Hamze Hamze; Ali Asghri; Seyed Abulghasem Mohammadi; Omid Sofalian; Soleiman Mohammadi
Abstract
IntroductionGrain growth in wheat depends on current photosynthesis and stem water-soluble carbohydrates (WSC). In semiarid regions with terminal drought, grain filling in wheat crops may depend more on stem WSC content than on current assimilates. Reduction in grain yield under drought is attributed ...
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IntroductionGrain growth in wheat depends on current photosynthesis and stem water-soluble carbohydrates (WSC). In semiarid regions with terminal drought, grain filling in wheat crops may depend more on stem WSC content than on current assimilates. Reduction in grain yield under drought is attributed to shorter duration of linear grain growth despite increased contribution of stem reserves to grain yield. The amount of stem reserves is measured either by changes in stem dry weight (indirect method) or by stem WSC content (direct method). Genotypic variation in the rate and duration of linear grain growth and in percent contribution of stem reserves to grain yield has a little evaluated in wheat. Materials and methods The objectives of this study were grouping of spring wheat recombinant inbred lines in term of phenological and partitioning of assimilates in normal and water deficit conditions. Plant materials used in this experiment, include 148 bread wheat recombinant inbred lines derived from the cross between Yecora Rojo and genotype No. 49. Lines were produced at Riverside University and through of Center of Excellence Molecular Breeding, University of Tabriz was placed at the disposal of this research. Studied lines with parents were planted on research farms of Mahabad University and Miyandoab Agricultural Research Center in 2014-2015. In both experiments used alpha lattice design with two replications under normal and water defect conditions. Irrigation in stress and non-stress treatments was done after 90 mm evaporation from class a pan, depending on the temperature and evapotranspiration until heading stage. In water deficit stress treatment, irrigation was stopped at heading stage. Measuring of these traits were done sampling before and anthesis stage. Results and discussionAccording to the combined analysis there was a significant difference between two normal and water deficit conditions in terms of days to head, remobilization, grain yield and remobilization portion in grain yield. Also genotypes had significant difference for all traits. Also, grain yield had a positive and significant correlation with days to heading, stem partitioning, spike partitioning and the remobilization rate in both conditions. Based on the results of cluster analysis, genotypes were classified into 4 groups in both conditions. In both conditions, genotypes 7, 17, 27, 32, 40, 50, 58, 62, 67, 69, 83, 106, 107 and 138 were classified in cluster number four which had the highest values of phonological traits, photosynthetic allocation and grain yield. These genotypes were identified as suitable genotypes for breeding programs to create high yielding cultivars. In factor analysis based on principle component analysis, in both conditions three factors were recognized that explained 77.85 and 68.76 percent of total variation of data under normal conditions and water deficit conditions respectively. ConclusionsIn this study, grain yield had a positive and significant correlation with days to heading, stem partitioning, spike partitioning and the remobilization rate in both conditions therefore genotypes with high values of these traits, had a high grain yield potential. Genotypes of 7, 17, 27, 32, 40, 50, 58, 62, 67, 69, 83, 106, 107 and 138 were identified as suitable genotypes for breeding programs to create high yielding cultivars.
Ramezan Gholizadeh Seresti; Hossein Sabouri; Ali Rahemi Karizaki; Hossein Ali Fallahi; Mohsen Rezaei
Abstract
Background Rice after wheat is the most important and essential foodstuff in the world and accounts for 40 to 50 percent of the world's food. Rice per capita consumption in iran is 40 kg. Rice consumption in Iran has increased since the 50 and is considered as an essential commodity and the second most ...
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Background Rice after wheat is the most important and essential foodstuff in the world and accounts for 40 to 50 percent of the world's food. Rice per capita consumption in iran is 40 kg. Rice consumption in Iran has increased since the 50 and is considered as an essential commodity and the second most important nutrient after wheat. Drought stress is a kind of potential reduction of soil water and in such a situation, plant to maintain and continue water absorption can regulate osmotic potential. The concept of stress in the plant is the negative and severe effect of a number of living or non-living factors in the plant. The environment is on the plant's natural plant that can disrupt dry matter production and decrease its yield. Plant adaptation behavior to drought stress plays an important role in stress tolerance. These behaviors are controlled and controlled by the genes and can function under non-stress conditions. The purpose of this experiment was to investigate the allelic variation, coupling analysis and haplotypes of continuous microsatellite markers to drought tolerance genes in rice. Materials and methods The plant material studied in this research, which included 48 varieties of rice, was prepared from Rice Research Center of iran, (IRRI) research institute and lines produced at Gonbad-e-Kavos University. In a completely randomized block design with Three replicates in two separate floodwaters (without stress) and drought stress in terms of diversity of morphological and genetic traits in Babol province in 2016 were surveyed. Irrigation was done from 40 days after transplantation, which was carried out on 2 irrigation regimes based on the crop year. In the processing stage, grain yield was taken from a surface area of one square meter and grain yield was calculated with a moisture content of 14%. Other traits including 100 grains weight, number of stems, number of filled grains, number of pods, plant height, panicle length, number of panicles, stem diameter, grain length, grain width, grain shape, straw weight, length of period, Flag leaf length, flag leaf width of 10 plants were randomly selected and traits were measured. Molecular studies were performed with nine microsatellite markers related to drought stress tolerance. Findings Considering the significance of interactions between cultivars and cultivations, the variance of the compound was divided into two distinct normal and stresses (Table 1-4, 2-4, and 3-4). Analysis of variance showed both in normal conditions and in drought stress Genotypes were significantly different for all studied traits in both conditions. The 48 genotypes examined were based on 9 microsatellite markers in a total of 31 alleles with an average of 44.3 alleles per gene site. The RM60 marker had the highest number of alleles (six), and RM 324 and RM472 markers had the lowest allele count (two). The average content of multiform data log (PIC) was 51.1, which showed RM22 and RM12093 with 0.68 and RM324 with the lowest of 0.14 (PIC). The results of coupling analysis showed that in the traits of yield and yield components for number of clusters, the number of three negative alleles (RM12093-A, RM60-B, RM22-E) and four alleles (RM216-B, RM28166-B, RM28166- C and RM324-A) had positive regression coefficients. For the number of grains in the cluster, there was a positive allele (RM22C) allele. Three positive alleles (RM19367-A, RM216-A and RM22-D) and a negative allele (RM472-A) were also detected for 1000-grain weight. The functional attribute was correlated with only one allele (RM510-C). The haplotype evaluation divided the microsatellite markers of the genotypes into 25 haplotype groups, of which 23 haplotypes were isolated and the other two groups had two genotypes in their subset. haplotype 1 group (48 and 47 genotypes) had the highest yield of 5540.9 kg / ha and in some cases it could be said that it had the highest drought tolerance. Discussion The comparison of the results of haplotype analysis and the analysis of the association of alleles with the evaluated traits showed that there is a correlation between the results of these two methods of examining the data for the obtained data. Combined analysis of variance showed that most of the studied traits were significant at 1% probability level.
Hassan Zali; Omid Sofalian; Tahereh Hasanloo; Mehrshad Zeinalabedini; Ali Asghari
Abstract
Background and objectiveRapeseed (Brassica napus L.) is a major crop cultivated worldwide mainly for oil, human consumption and renewable fuel. Plant growth is controlled by several factors, of which water plays a vital role. Large parts of the world are increasingly affected by drought. Drought stress ...
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Background and objectiveRapeseed (Brassica napus L.) is a major crop cultivated worldwide mainly for oil, human consumption and renewable fuel. Plant growth is controlled by several factors, of which water plays a vital role. Large parts of the world are increasingly affected by drought. Drought stress is one of the most important abiotic factors which adversely affect growth, metabolism and yield of crops worldwide. Drought stress, during any particular growth stage of crops results in yield reduction. Under shortage of water, plants accumulate metabolites, such as sugars and inorganic ion, to regulate osmotic potential. Mixed linear model (MLM) methods have proven useful in controlling for population structure and relatedness within genome-wide association studies. Materials and methodsIn other to identify the informative markers of physiologic traits and indices of 22 canola genotypes under drought stress, 36 microsatellite markers linked to the QTLs controlling morphologic characteristics (shoot dry weight, total dry weight, root dry weight and plant height) under drought stress were used. In order to identify genomic regions involved in controlling physiological traits, GLM and MLM association models were used. Results and discussionsThirteen six selected primers produced 166 bands, with 157 (94.58%) being polymorphic, indicating considerable genetic diversity among lines and genotypes. The polymorphic information content values of loci was varied from 0.043 (CB10502) to 0.398 (CB10234), respectively. The highest PIC values were for CB10234, CB10143, SR94102, NA10-E02 and BRMS-030 primers, and the lowest for CB10502, Ol10-B02, CB1003, and FITO133 primers.The results of Mantel test showed that the correlation coefficient for stress and non-stress conditions was 0.024 and 0.06, respectively. According to this test, the correlation between physiological traits and molecular data matrix was not significant. Based on the 36 microsatellite markers used in this study, population genetic structure subdivided into eight subpopulations (K=8) that barplat results also confirmed it. In association analysis based on GLM and MLM models, 6 and 16 loci showed significant relation with assessed traits at non-stress conditions, respectively. Also based on GLM and MLM models, 42 and 46 loci indicated significant relation with assessed traits at drought stress conditions, respectively.In this study, 16 markers include Ol10-B02, BRAS084, Na10E02B, BRAS074a, CB10526, Na10-C01f, CB10003b, OL11-H06, FITO133, Na14-096, BRAS072a, CB10143, NA10-E02b, BRMS-031, CB10502, CB10010 hadn’t significant relationship with the physiological and morphological traits. The markers BRAS041, CB10597, BRMS-036, Sorf73b, CB10081c, MR013c, Na12-B05 and NA14-E08a were associated with the traits in non-stress conditions. Also, the markers CB10597, BRMS-036, SR94102, BRAS100, CB1059b, BRMS-024, BRMS-096, BRMS-30, MR013c and Pmr52 showed a significant relationship with physiological and morphological traits in drought stress conditions. ConclusionFinally, the markers BRMS-036, SR94102, BRAS100, CB1059b, BRMS-024, BRMS-096, BRMS-30, MR013c and Pmr52 showed the most significant relationship with physiological traits in drought stress conditions. Therefore, it is probably that these markers would be a very suitable and promising candidate for drought stress tolerance programs, such as marker assisted selection for canola. Also, probably the genes associated with these traits are near genes in the chromosomal location and may be useful in providing basic information about the indirect selection of traits through relevant markers.
Bahareh Khatonabadi; Ali Akbar Ehsanpour; Amir Hossein Forghani
Abstract
Introduction The growth and production of crop plants are strongly affected by various environmental stress. Salinity stress affects all stages of plant development including germination, bud growth, vegetative growth, flowering, and fruiting. During the past few years, several genes that encoding various ...
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Introduction The growth and production of crop plants are strongly affected by various environmental stress. Salinity stress affects all stages of plant development including germination, bud growth, vegetative growth, flowering, and fruiting. During the past few years, several genes that encoding various structural and regulatory proteins have been used to produce tolerant plants of abiotic stress. Tolerant plants have been selected by improving our knowledge about molecular mechanism of stress tolerance in plants. Plants increase organic osmolytes such as proline, glycine betaine, polyols, alcoholic sugars, and soluble sugars to modulate osmotic stress. The P5CS gene (proline-5-carboxylate-synthase) is a key enzyme in the pathway for proline synthesis and this amino acid increases resistance of plants to salinity. Although there are many reports about the key role of accumulation proline in mechanism of salinity tolerance, a little information is available about physiological and non-enzymatic antioxidant response of transgenic plants by P5Cs overexpression in salt stress. Therefore, the aim of this study was to evaluate physiological and non-enzymatic antioxidant responses of transgenic and non-transgenic tobacco to salinity under in vitro culture. Materials and methods In order to achieve this goal, transgenic and non-transgenic plants were selected by PCR experiment with NPTII: P5CS proprietary primers. Consequently, the expression of the P5CS gene in transgenic plants was significantly higher than non-transgenic plants. To investigate the mechanism of salt tolerance in tobacco, transgenic and non-transgenic tobacco plants were grown on MS medium containing 0, 100, 150, 200 mM NaCl. After 4 weeks of treatments, fresh and dry weight, photosynthetic pigments, sodium and potassium, proline, phenol, anthocyanin, flavonoid, ascorbate, and hydrogen peroxide were measured. Results and discussion Based on the results, dry and fresh weight as well as chlorophyll content in transgenic plants decreased less than non-transgenic plant under salt stress. For example, the fresh weight of non-transgenic plants in the medium with 100 and 200 mM NaCl decreased by 47% and 33% and their dry weight decreased by 23 and 33%, respectively compared with transgenic plants. Total chlorophyll content of transgenic plants in the medium with 100, 150 and 200 mM salt was improved by 25%, 22%, and 41% compared with non-transgenic plants, respectively. Also, the leaves of transgenic plants accumulated less sodium than non-transgenic plants in response to salinity stress. By adding 100, 150 and 200 mM salt to medium, the level of sodium in transgenic plants decreased by 50%, 17%, and 18% compared with non-transgenic plants respectively. Moreover, the level of phenolic, anthocyanin and flavonoid compounds in the transgenic plants were less than non-transgenic plants by adding salt to medium. The proline content of both transgenic and non-transgenic plants increased in response to salinity. In addition, there was a significant increase in proline content of transgenic plants compared to non-transgenic plant under salt stress. The ascorbate content in transgenic and non-transgenic plants did not change significantly in response to salinity. However, the hydrogen peroxide decreased significantly in transgenic plants as compared with non-transgenic plants in salt stress. The results showed that the accumulation of hydrogen peroxide in transgenic plants in the medium with 100, 150 and 200 mM salt was 83%, 41%, and 23% lower than non-transgenic plants, respectively. So, it seems that transgenic and non-transgenic tobacco plants were salt tolerant and salt sensitive respectively. It has been suggested that high proline content may lead to salt tolerance in plants. According to our experiment, overexpression of P5CS gene increased proline content in other plants and improved salinity resistance in transgenic plants.
Massoumeh Zamani Farsi; Mehdi Rahimi; Maryam Abdoli Nasab; Amin Baghizadeh
Abstract
Introduction Maize (Zea mays L.) is considered as one of the most important cereals in the field of world production. Water stress due to water shortages and its various forms is one of the main and most common limiting factors of crop yield, especially in arid and semi-arid regions of the world. Therefore, ...
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Introduction Maize (Zea mays L.) is considered as one of the most important cereals in the field of world production. Water stress due to water shortages and its various forms is one of the main and most common limiting factors of crop yield, especially in arid and semi-arid regions of the world. Therefore, in corn, identification, selection and use of tolerant cultivars against drought stress in order to prevent the reduction of crop yield is considered as one of the most important and essential issues in breeding programs. In order to design and implement an effective and useful program, knowledge of the genetic control of the studied traits is essential the impact of environmental factors and the interaction between genetic and environmental factors. Among different methods of genetic analysis of quantitative traits, diallel analysis using Hayman method as an appropriate and efficient method for estimating the genetic structure of the populations in the relatively short time was considered by plant breeders. Therefore, the present study was conducted to evaluate the gene effects, heritability and the control of yield and its components in drought stress conditions compared to normal conditions in corn. In order to select suitable breeding methods and take an effective step in the production of high yielding maize cultivars. Materials and methods In order to estimate the gene action and heritability of important agronomic traits, five S7 maize lines in a 5×5 half-diallel cross with F1 hybrids derived from them in a randomized complete block design with two replications in two normal conditions (irrigation intervals of 5 days) and drought stress (10 days irrigation) were cultivated at the Research Farm of Graduate University of Advanced Technology, Kerman, Iran in 2017. Number of ear, grain number per row, grain row number, grain number per ear, ear length, 100-grain weight and grain yield per plant were evaluated in two conditions. The graphical analysis was carried out using the Hayman method and genetic parameters including additive variance (D), non-additive variance (H1 and H2) and covariance of additive with dominance effects (F) were also estimated by Hayman's proposed regression method. In order to carry out the diallel analyzes by Hayman method in two normal and drought stress conditions and combined analysis of variance was used SAS command. Results and discussion Combined analysis of variance showed that there was a significant difference between genotypes, environment and genotype×environment interaction for all studied traits, indicating the genetic differences between lines and corn hybrids. The simple effect of a for all traits, except for the number of ear and its interaction with the environment, was significant for all traits except number of ear, grain number per row and grain yield per plant which showed that additive effects play a role in controlling these traits and showed a different behavior in the two environments. The simple component b, which includes non-additive effects, was significant for all traits, and its interaction with the environment was also significant for all traits. The significance of the interaction between a and b effects with the environment indicates the difference in the type of additive and non-additive genes in both normal and drought stress conditions. Generally, the gene type for controlling traits and their gene action, potential of dominance and recessive genes in parents, and additive and dominance effects were different for most studied traits of this research in both normal and drought stress conditions. The graphical results of Hayman's analysis showed the role of over-dominance genes effects in controlling most traits in normal and drought stress conditions. Conclusions The results of this study showed that although genes with both additive and non-additive effects played a role in controlling the traits, the contribution of each of these effects was different in controlling each of the traits. Also, the control of these traits was different in both normal and drought stress conditions, and the genes controlling these traits differed from environment to environment. The results of narrow sense heritability and Hayman graphic analysis of traits showed that these traits were controlled by the non-additive gene effects. Therefore, it can be said that in order to breed and improve the genetic value of the population for these traits (yield and its components), the selection method will not be very successful, but it should use the phenomenon of heterosis and crossed the parents to produce hybrids.
Hossein Farzadi; Naser Zarifinia; Ali Assareh; Ahmad Ali Shoushi Dezfuli
Abstract
Introduction Water stress is the most important cause of reduced wheat yield in semi-arid areas. In most regions under wheat cultivation, especially in regions with Mediterranean climates, wheat plants are exposed to various stresses during the seed filling. Seed filling often occurs when temperature ...
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Introduction Water stress is the most important cause of reduced wheat yield in semi-arid areas. In most regions under wheat cultivation, especially in regions with Mediterranean climates, wheat plants are exposed to various stresses during the seed filling. Seed filling often occurs when temperature rises and less water is available. Irrigated wheat in Khuzestan Province mainly faces end-season drought caused by limited water supply on the one hand and the reduced precipitation and competition by other crops for water on the other hand. Therefore, introducing wheat genotypes tolerant to end-season drought is of great importance for this Province. Materials and methodsThis research was conducted at the Agricultural and Natural Resources Research Center of Safiabad- Dezful in the crop years 2014-2015 and 2015-2016. Eight promising durum wheat lines in warm regions in Iran together with the Behrang cultivar were studied. The following two separate experiments were conducted using the randomized complete block design with two replications: (1) full irrigation until maturity and (2) application of end-season water deficit stress through irrigation cessation from the spike emergence stage to physiological maturity.Results and discussion Results indicated that the effect of year was significant under drought conditions but not significant in the absence of drought conditions. Moreover, the mutual effect of genotype and year were significant in the absence of drought but not significant under drought conditions. The mean two-year yield under conditions without water deficit stress was 4844 kg/ha, with the highest average seed yield (5101 kg/ha) belonging to line 1 and the lowest (4669 kg/la) to line 2. Although yield of line 3 under conditions without water deficit stress (5039 kg/ha) was a little lower than that of line 1, it enjoyed higher yield stability compared to the other lines because it had the average ranking of 2.5 and the standard deviation of 0.5. Furthermore, the mean two-year seed yield under end-season drought conditions was 3991 kg/ha, with the highest mean seed yield of 4332.5 kg/ha belonging to line 4 and the lowest (3710 kg/ha) to line 9. Under end-season drought conditions, line 4 had the largest seed yield and the highest yield stability in the two years of experiments with the average ranking of 2.5 and the standard deviation of 0.5.Principal component analysis (PCA) and the shape of the by plot were employed for the simultaneous study of the relationships between the genotypes and the quantitative drought tolerance indices. Results of the PCA showed that most of the variance in the data could be explained by the two components of PCA1 (the first component) and PCA2 (the second component) with 63% and 30%, respectively. In addition, among all of the calculated components, only PCA1 and PCA2 had eigenvalues higher than 1 (5.67 and 2.66, respectively). ConclusionThe strong positive correlation between seed yield in the two environments with and without water stress and the STI, MP, and GMP indices indicated that these indices had a high efficiency in selecting drought tolerant genotypes. Based on the results of PCA, genotypes 1 and 3 were selected as water deficit stress tolerant genotypes because of their high PCA1 and suitable PCA2 values and also due to their closeness to the important drought tolerance indices MP, GMP, K1STI, K2STI, and STI; whereas lines 6, 9, and 10 were introduced as water deficit stress sensitive genotypes because of their low PCA1 and PCA2 values and also due to their closeness to the SSI vector. Line 7 was between important drought tolerance indices and drought sensitivity indices and enjoyed relatively desirable drought tolerance, but the high estimated values of SSI and TOL for this cultivar indicated that it lacks suitable yield stability. Moreover, this cultivar is close to the Yp vector, which shows that drought tolerance in this genotype is due to its high yield in stress free environments.
Hassan Hamidi; S.Sanaz Ramezanpour; Masoud Ahmadi; Hassan Soltanloo
Abstract
IntroductionThe dry and semi-arid climate of the country has become inevitable the cultivation and production of crops under the conditions of environmental stresses (drought, salinity and heat).Crops are show different reactions against these stresses. The occurrence of any of the stresses, or a combination ...
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IntroductionThe dry and semi-arid climate of the country has become inevitable the cultivation and production of crops under the conditions of environmental stresses (drought, salinity and heat).Crops are show different reactions against these stresses. The occurrence of any of the stresses, or a combination of them, leads to a reduction in production. Sugar beet is one of the plants that tolerates these stresses. The aim of this research was to determine the tolerance of sugar beet S1 pollinator lines to drought stress in field conditions in terms of yield and physiological traits so that based on the results, a model could be presented for better and more effective management of water on farms. Materials and methods This experiment was conducted to evaluate the physiological characteristics of 34 sugar beet genotypes (30 S1 pollinator lines with three controls including Shokoofa, Motahar and Paya and Origin population) under normal irrigation and drought stress conditions in a Randomized Complete Block Design with three replications at experimental field of Khorasan Razavi Agricultural and Natural Resources Research and Education Center in 2016. Irrigation was done routinely up to the thinning and weeding stage. Subsequent irrigations were done after 90 mm and 200 mm evaporation from the class A evaporation pan in non-stress and stress conditions, respectively. In this research, traits such as root yield, sugar content, sugar yield, chlorophyll, Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), Index of difference between the temperature of environment and leaf, leaf relative water content, specific leaf weight, succulence index, specific leaf area and electrolyte leakage were measured. Analysis of variance and estimation of correlations were performed with SAS 9.1 software and also factor analysis was done using Statgraphics 18 software. Results and discussionResults showed that in both conditions (non-stress and drought stress conditions) there are significant different (p≤0.01) between all genotypes for all traits. Combined analysis of variance showed that there was a significant difference (p≤0.01) among studied genotypes and different irrigation regimes in the most traits. In normal irrigation and drought stress conditions, Motahar and S1-15 line had the highest sugar yield (9.09 and 10.5 ton/ha), respectively. Correlation coefficients showed that root yield had a positive and significant correlation with sugar yield and NDVI in normal and stress conditions. In both conditions (non-stress and drought stress conditions), factor analysis led to introduce four main factors which explained 69.55 and 74.75 percent of total variation, respectively. ConclusionsIn general, the results showed that there are considerable variations in yield and physiological traits among the different genotypes of sugar beet due to the potential for drought tolerance in them.
Amir GHolizadeh; Hamid Dehghani; Mostafa Khodadadi
Abstract
Introduction Coriander is an annual herb belongs to the umbel family and is native from North Africa to south-western of Asia. Coriander is one of the important medicinal plants that used in the pharmaceutical industry and it mainly cultivated and widely distributed for the fruits. The dried fruits are ...
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Introduction Coriander is an annual herb belongs to the umbel family and is native from North Africa to south-western of Asia. Coriander is one of the important medicinal plants that used in the pharmaceutical industry and it mainly cultivated and widely distributed for the fruits. The dried fruits are widely employed as a condiment, especially for flavoring of sauces, meat products and bakery and confectionery items. Also, coriander fruits are as a source of essential oils and fatty oil. Water deficit stress is one of the most important factors limiting the growth and survival of the plants in arid and semi-arid regions in the world. Water is a major component of the plant materials and significantly influence the quantity and quality of plant production. Drought stress leads to significant changes in the yield and composition of essential oils in aromatic and medicine plants. So that, it was reported that water deficit increased essential oil content but decreased essential oil yield in coriander. Iran with an average annual rainfall of 240 mm is classified as arid and semi-arid regions of the world. However, Iran is one of the world’s commercial coriander producers. Coriander has been cultivated for many years in different parts of Iran. Therefore, development of drought-tolerant cultivars with high essential oil and fatty oil yield is important in coriander. Indirect selection through yield components and yield-related traits is one of the most effective methods for improving complex traits such as fruit yield. Therefore, this research was conducted in order to understand the genetic association between quantitative and qualitative traits and also to identify the indirect selection indices for selection appropriate genotypes in coriander. Materials and Methods F1 and F2 generations derived from half-diallel crosses between six endemic coriander genotypes including Isfahan, Hamedan, Bushehr, Mazandaran, Markazi and Alborz, along with with their parents were evaluated in three irrigation regimes through randomized complete block design with three replications in each experiment during the growing season in 2016. Plants were grown in different irrigation regimes: well-watered (WW), moderate drought stress (MDS) and severe drought stress (SDS). The plant height, leaf number, branch number per plant, umbel number per plant, fertile umbel number per plant, fruit number per plant, thousand fruit weight, fruit yield, biological yield, essential oil content, fatty oil content, essential oil yield, fatty oil yield, SPAD chlorophyll content, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, relative water content and ion leakage were measured. Results and Discussion Results showed that fruit yield had the significant positive genetic correlation with days to flowering, SPAD chlorophyll content, relative water content, fruit number per plant and thousand fruit weight. Therefore, these traits could be used as suitable criterion for selection to increase fruit yield in drought stressed conditions. Consideration, the genetics of early ripening and fruit yield and a significant positive genetic correlation between days to ripening and fruit yield, improving coriander fruit yield under drought stress may be possible through breeding for drought escape. There were the positive genetic correlations between fruit yield and other economical traits in different irrigation regimes. Therefore, improving fruit yield can simultaneously be led to improve in the economical traits. Conclusion Generally, the results indicated that traits of days to flowering, SPAD chlorophyll content, relative water content, fruit number per plant and thousand fruit weight could be used as suitable criterion for selection to increase fruit yield in drought stressed conditions. Also, improving fruit yield can simultaneously be led to improve in the economical traits in both the non-stressed and drought stressed conditions
Azim Ahmadi; Majid Amini Dehaghi; Mohammad Hossein Fotokian; Mohammad Sedghi; Cyrus Mansourifar
Abstract
IntroductionDrought is one of the most important environmental stresses that influence various growth steps of the plant including germination, plantlet establishment, and production all over the world (Bacilar et al., 2007; Ben Ahmad et al., 2009). Drought stress has significantly increased in recent ...
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IntroductionDrought is one of the most important environmental stresses that influence various growth steps of the plant including germination, plantlet establishment, and production all over the world (Bacilar et al., 2007; Ben Ahmad et al., 2009). Drought stress has significantly increased in recent years because of changes in climate and increasing CO2 levels. Therefore, identification of the resistant plant varieties against drought stress in a necessity. Investigation the enabling mechanisms of plants to adapt to drought stress and protect their growth in that condition can help to select the resistant plants against drought stress to be cultivated in dry and semi-dry regions. Identification of the physiological mechanisms Lentil with the scientific name of Lens culinaris is from leguminous, one-year, long-day, self- pollinated, and diploid family (2n=14) with mean 5.28% protein. Lens culinaris is resistant to drought. Materials and methods12 Lens culinaris genotypes (Table 1) were examined in rainfed and deficit irrigation conditions in 2015-2016 agricultural years as the split spots based on randomized complete block designs with three repetitions whose main irrigation factor was in 2 levels (rainfed and deficit) and the secondary factor of genotypes in two individual Ardabil agriculture research stations and central part of Germi city in different conditions and climates to evaluate the genetic varieties of Lens culinaris cultivars, screening the quantitative indexes of resistance against drought, and identification of the resistant cultivars against drought. All plots were simultaneously irrigated in two steps of flowering and pot filling in 10ml in deficit irrigation treatment in each region and weren’t irrigated in stress treatment or rainfed and just raining was used up to the end of harvest. Each test unit was made of 4 cultivation line with 4m length, 30cm row distance, and 133 bushes in each row. Hand weeding was done in several steps to fight with weeds. Each genotype is harvested in proportion to its physiological consideration. In this step, two edge lines and 0.5m of two middle lines end were omitted to remove edge effect. Harvest was with hand. Seed performance was determined after threshing and separating the seeds from the straw based on seed weight (gr). Physiological characteristics were measured after the plant sheathing in both rainfed and deficit irrigation typesResults and discussionTable of the combined variance analysis (Table 1) showed that the significant difference was observed among proline, chlorophyll a and chlorophyll b and peroxidase enzyme values of two cultivation methods, the comparison of the mean chlorophyll a and chlorophyll b (ml/gr) of wet weight in Germi region was 0.22 and 0.079 with the significant difference from Ardabil region. The reaction of chlorophyll a and chlorophyll b to drought stress may be resulted by the plant metabolism tolerance in addition to the genetic differences against drought, and lack of the significant reaction between chlorophyll to stress can be attributed to the growth reduction in leaf. There was a significant difference in proline (μm/gr of wet weight) in Germi and Ardabil, but the amount of enzyme peroxidase (μgr of enzyme/gr of leaf) was higher in Ardabil. Proline accumulation is a popular physiological response of plants to the extensive range of bio and non-bio stresses (Geravandi et al., 2011). The maximum imposed damage by drought stress was for proline of Germi; as though, stress increased 23% of proline than Ardebil condition. In Gunes et al. (2008) research, drought stress after pollination significantly increased proline. There was a significant difference between rainfed and deficit irrigation conditions based on variance analysis. Bilesavar cultivar was considered as a control sample with the maximum peroxidase enzyme. ConclusionsThe results of this test show that in rainfed cultivation (drought stress) enzyme activity of the antioxidant and peroxidase, ascorbate peroxidas, proline and some characteristics for resistance plant against drought stress are increase.
Hamzah Shirui; Mehrshad Barary; Ali Hatami; Ali Ashraf Mehrabi
Abstract
In order to investigate the effect of supplemental irrigation and plant density on growth characteristics, yield and yield components of three dry lentil cultivars, Experiment in the crop year 2010 - 2011 A randomized complete block design with four replications was used in the research field of the ...
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In order to investigate the effect of supplemental irrigation and plant density on growth characteristics, yield and yield components of three dry lentil cultivars, Experiment in the crop year 2010 - 2011 A randomized complete block design with four replications was used in the research field of the Faculty of Agriculture of the University of Ilam. Rainfed conditions with complementary irrigation and non-irrigated dryland were the main factors of the experiment. Planting density factor (at two levels of 200 and 400 plants m-2) and lentil cultivar (including three cultivars Gauche saran, Bile saver, Kimia) formed the sub-plots of the experiment. The results showed that supplemental irrigation increased the number of full pods and decreased the number of empty pods and increased the number of pods per plant and single plant yield. An increase in the density of all traits (height, number of flowers, number of main and sub-branches, number of pods, single dry weight and yield per plant) decreased and only the number of empty pods increased. According to the results, Bile saver cultivar had the highest number of main and secondary shoots as well as the highest dry weight of a single plant. The highest number of flowers and number of pods per plant belonged to Kimia cultivar interaction effect on a number of pods per plant was significant at 1% probability level. The number of hollow pods and the number of branches were also affected by irrigation interaction. The interaction of all three factors on the number of branches was significant at one percent probability level.
Mona Poureisa; Majid Nabipour; Musa Meskabashi
Abstract
IntroductionIn semiarid regions with a Mediterranean climate, grain-filling period of barley (Hordeum vulgare L.) faces different kinds of biotic and abiotic stresses including water deficit, heat stress and foliar diseases. Current assimilation as a carbon source for grain filling is dependent on light ...
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IntroductionIn semiarid regions with a Mediterranean climate, grain-filling period of barley (Hordeum vulgare L.) faces different kinds of biotic and abiotic stresses including water deficit, heat stress and foliar diseases. Current assimilation as a carbon source for grain filling is dependent on light absorptive green surfaces after anthesis. This source decreases normally due to natural senescence and different stresses. Simultaneously, demand of growing grain increases in addition to the demand of maintenance and respiration of live plant biomass. So stem reserves are one of the important carbon reserves for grain filling. (Blum, 1998). Stem reserves are mainly in the form of WSC (Kuhbauch and Thome, 1989; Przulj and Momcivilic, 2001; Schnyder, 1993). The final grain weight is one of the main determinant components of yield, which is determined by two factors: grain filling rate and grain filling period (Blum, 1998, Yang and Zhang, 2005). These two components are influenced by environmental and genetic factors and are physiologically completely independent of each other. Ehdaie et al. (2008) studied grain growth in 11 wheat genotypes. Under drought stress, 26% grain weight reduction was due to 29 percent reduction in grain filling rate and 50 percent grain filling period. The aim of this experiment was to investigate the changes in grain weight and carbohydrate concentration of four barley cultivars under end of season drought stress, and to investigate the role of stem reserves and current photosynthesis in grain weight stability under drought stress.Materials and methods A pot experiment was carried out in a factorial design with three replicates at the faculty of Agronomy, University of Shahid Chamran in the duration of 2010-2011 growing seasons. Four spring barley cultivars (Hordeum vulgare L.) selected from preliminary experiment including Nimruz, Jonub, Nosrat and Torkaman were grown under two water treatments including water stress vs. fully irrigation. The chlorophyll Content of flag leaf was assessed from anthesis to maturity at 5-day intervals from the same-age plants. Sampling was done from anthesis to maturity at 5-day intervals from the same-age plants. The spikes were removed and the weight of nine middle grain was measured. The linear rate of grain growth was estimated by The linear regression analysis for each cultivar in well-watered and droughted treatment. The penultimate internodes were separated from stems and then frozen in liquid nitrogen after removing leaf sheet. Five main spikes at maturity were harvested for assessment of main spike grain yield, the number of grains and grain weight. WSC were extracted based on Sonnewald et al. (1992) and measured according to Dubois et al. (1956). Results are expressed as milligrams of WSC per gram of fresh weight for WSC concentration. The mobilized WSC (MWSC) in penultimate internode was estimated as the difference between postanthesis maximum and minimum WSC concentration. Remobilization efficiency (Re) of WSC was estimated by the proportion (%) of postanthesis maximum WSC concentration of penultimate internode that mobilized. Result and discussionSignificant difference was observed among cultivars in WSCc at anthesis. Jonub showed the highest and Nosrat showed the lowest concentrations. Inspite of lower WSC concentration (WSCc) at anthesis, Torkaman and Nimruz could be set in the same group with Jonub, based on maximum WSCc (Fig. 1). The ratio of preanthesis WSC to total reserved WSC was different among cultivars. Jonub had the highest ratio, while Torkaman had the lowest ratio.Water withholding elevated remobilisation efficiency by 10%. Nosrat was affected the most by water-stressed conditions by increase of 47% in mobilised carbohydrates and increase of 44% in remobilisation efficiency. On the other hand, Nimruz and Jonub had high level of WSC remobilisation in both conditions and these cultivars weren’t highly affected by drought. Water withholding increased the rate of chlorophyll loss by 66%. Nosrat and Nimruz showed the highest and the lowest rate of chlorophyll loss in both circumstances respectively. On the other hand, Jonub and Nosrat showed the highest and the lowest increase in this feature by entering drought. Drought decreased grain filling rate by 35 that resulted in decrease of 15% in grain weight. Reduction by 17% was observed for yield of main spike by entering drought that was mainly due to the decrease of grain weight , Because grains per spike didn’t change. ConclusionCultivars were different in WSC-related traits such as WSC concentration at anthesis, maximum WSC concentration and rate of WSC accumulation in ten-day period after anthesis. Water withholding elevated WSC remobilisation efficiency. Water withholding increased the rate of chlorophyll loss by 66%. Drought decrease the the rate of grain filling by 35%. The decrease of 15% in grain weight led to decrease of 17% in grain yield of main stem. Cultivars showed different manner about use of current photoassimilates and reserved WSC in the second phase of grain filling that led to different changes in grain weight by entering drought conditions.
Neda Ebadi; Raouf Sseyed Sharifi; Mohammad Sedghi
Abstract
Introduction Drought is the most severe abiotic stress factor limiting plant growth and crop production. Many physiological processes in plants are impaired by drought stress. Also this stress can damage the photosynthesis of plants, pigments and plastids reduce chlorophyll a, chlorophyll b and other ...
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Introduction Drought is the most severe abiotic stress factor limiting plant growth and crop production. Many physiological processes in plants are impaired by drought stress. Also this stress can damage the photosynthesis of plants, pigments and plastids reduce chlorophyll a, chlorophyll b and other carotenoids, hydrolyze proteins and prevalent photochemical reactions in most plants. The response of plants to drought stress depends on several factors such as developmental stage, severity, duration of stress, and cultivar genetics. Several strategies have been developed in order to decrease the water limitation-induced toxic effects on plant growth, among them use of bio fertilizers and supplementary irrigation play a key role in yield improvement. The aim of this study was to investigate the effects of supplementary irrigation and biofertilizers on yield and some biochemical and physiological traits of barley under rain fed and supplementary irrigation condition. Materials and methods In order to study the effects of biofertilizers on yield and some biochemical and physiological traits of barley (Sahand cultivare) under rainfed and supplementary irrigation conditions, a factorial experiment was conducted based on randomized complete blocks design with three replications in the village of Khalkhoran viand of Ardabil province in 2016-2017 cropping season. Experimental factors were irrigation levels (no irrigation as rainfed, supplementary irrigation at 50% heading and booting stages) and biofertilizers application at four levels (without bio fertilizers as control, application of mycorrhiza, Azetobacter, and both application of mycorrhiza with Azetobacter). Results The results showed that the highest catalase, polyphenol oxidase and peroxidase enzymes activity (99.9, 66.9 and 78.2 OD µg Protein min-1 respectively), proline and soluble sugars content (10.25 µg/g FW and 105.7 mg g-1 FW) were obtained in both applications of mycorrhiza and Azetobacter under rain fed condition. The highest grain yield (2682 kg.ha-1) was obtained from supplementary irrigation at heading stage with both application of mycorrhiza and Azetobacter, and the lowest it (2065 kg.ha-1) was obtained in no application of bio fertilizers under rainfed condition. In conclustion, it seems that application of bio fertilizers and supplementary irrigation can be as a suitable method for increasing grain yield of Sahand barley cultivare under rainfed conditions. In conclustion, it seems that application of bio fertilizers and supplementary irrigation can be as a suitable method for increasing grain yield of Sahand barley cultivare under rainfed conditions.
Ali Karimi; Mohammad Eghbal Ghobadi; Mokhtar Ghobadi; iraj Nosratti
Abstract
Introduction Drought is one of the most important risks to crop growth. Corn is plant with spring growth and its production in our country that summer rain is lacking, depends heavily on irrigation water. Any change in irrigation time in each period of growth causes problems on yield. Delay in irrigation ...
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Introduction Drought is one of the most important risks to crop growth. Corn is plant with spring growth and its production in our country that summer rain is lacking, depends heavily on irrigation water. Any change in irrigation time in each period of growth causes problems on yield. Delay in irrigation that does not damage the performance depends on growth stage, stress duration, air temperature, soil texture and the type of hybrid. Accordingly, this experiment was conducted to investigate the possibility of removing some of the irrigation steps or reducing irrigation water levels at some stages of development, leading to the least yield loss. Materials and methods In order to evaluate the effect cutting of irrigation at different times of growth on yield and yield components and some physiological traits of corn (SC704) carried out a research in a randomized complete block design (RCBD) with three replications in the village of Ciahgol, Gilangharb (tropical region), Kermanshah, Iran, in summer 2015. Treatments including control (irrigation each week) and no irrigation (NI) for two weeks (from 7, 21, 35, 49, 63, 72 and 91 days after planting) and no irrigation (NI) for three weeks (from 7 , 28, 49, 70 and 91 days after planting). In all treatments was delayed only once irrigation for two or three weeks and before and after the no irrigation treatments was done each week. Soil text was clay-loam. Each plot including 5 rows × 6 meter length. Plant density was 85000 plants per hectare. In this experiment were measured economic yield, biological yield, water use efficiency, plant height, chlorophyll a, b and total, proline, kernels traits and ear. Finally, data analyzed by SAS software and means compared with LSD test. Results and discussion The results of analysis of variance showed that NI for 3 weeks cause decreased grain yield, 1000-kernel weight, plant height, water use efficiency of biological and economic, chlorophyll a, chlorophyll b and increased proline. Maximum of grain yield (13600 kg ha-1) and 1000-kernel weight (232 g) obtained at control treatment and at 3 weeks NI from 49 days after sowing (tassel emergence), were 0.0 and 0.0 kg ha-1, respectively. Grain yield reductions in most treatments were due to the decrease in the number of rows, number of kernels per row and 1000-seed weight. Biomass yield at this treatment of stress decreased about 66 percent compared to control. Thousand grain weights at control treatment and two weeks NI from 7 days after of sowing had the highest amount (232 g) and the lowest was at 3 weeks NI and 70 days after sowing (220 g). The highest and lowest number of kernels per row was in control (50) and three weeks in the treatment of NI from 49 days after sowing was zero. Treatment two weeks of stress from 7 days after sowing had the maximum number of rows per ear (14.9). The highest number of grains per ear was two weeks in the treatment of NI from 7 days after sowing (732.1) and the lowest total grains per ear in the treatment of 11 (zero). With increasing drought duration (two weeks to three weeks) at the beginning of the emergence of male inflorescence reduced number of seed per row, So that was two weeks in the treatment of NI from 49 days (15.1) and at 49 days of treatment three weeks of stress (zero). Control had the highest plant height (206 cm). The lowest of plant height was at three weeks of treatment 28 days after sowing (123 cm) that decline of about 40 percent Compared to control. Conclusions However, results showed that early and late stages of corn growth had the lowest susceptive and the most resistance were anthesis and grain filling period according as no irrigation for two weeks cause decreased significant in grain yield. Acknowledgements We thank all of friends that help us. This work was supported by the Razi University, Campus of Agriculture and Natural Resources.
Khatereh Tavakoli Oujani; Varahram Rashidi; Mehrdad Yarnia; Alireza Tarinejad; Bahram Mirshekari
Abstract
Introduction Maize (Zea mays L.) is one of the most important crops and after wheat and rice, it has the third place among cereals. Water in arid and semi arid regions is one of the most important limiting factors for crop production. And water resources in the country are limited, new hybrids that are ...
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Introduction Maize (Zea mays L.) is one of the most important crops and after wheat and rice, it has the third place among cereals. Water in arid and semi arid regions is one of the most important limiting factors for crop production. And water resources in the country are limited, new hybrids that are suitable for drought tolerance and their economic performance should be developed. Various studies have shown that mycorrhizal fungi can have adverse effects on drought stress in plants The reduction of arbacterial mycorrhiza with the roots of most plants has a similar relationship with the plant in the absorption of mineral elements, soil and In addition to enhancing food absorption, this fungi may stimulate growth regulators, increase photosynthesis, improve osmotic pressure regulation in drought conditions, and increase resistance to environmental stress. Materials and methods To investigate the reaction of some physiological traits, grain yield and its components of maize cultivars to water deficit under the conditions of mycorrhizal application and non-application, A split factorial experiment based on randomized complete block design was performed during two years 2015 and 2016 , at the Research Station of the Faculty of Agriculture, Islamic Azad University, Tabriz Branch. The main factor was drought stress based on evaporation from class A pan with two levels of 70 mm (as control) and 140 mm (as stress) and subsidiary factor including 14 factorial combinations of application and non-application of mycorrhiza on seven maize cultivars (260, 301, 400, 4015, 703, 704 and 705). The traits measured included relative water content, chlorophyll index, leaf area index, number of ear per plant, ear length, number of seeds per row, row number of seeds, weight 300 hundred seeds and grain yield. Results The results of combined analysis of the data showed that the interaction of year in stress in cultivar and also stress in the cultivar in Mycorrhiza was significant on grain yield. Based on the comparison of mean values, the highest seed yield was related to single-cross 301 and in non-stress conditions. While the lowest grain yield was related to single-cross 4015 in drought stress conditions. The highest yield in non-stressed conditions and drought stresses was in single-cross 400 and 301 respectively under microscopic conditions. In other words, mycorrhiza had a positive effect on some of the cultivars under stress conditions. The correlation coefficients between traits showed that in both conditions of normal irrigation and drought stress, grain yield had the highest correlation with 300 grain weight. Conclusion The results of this study showed that the occurrence of drought stress in corn field from the 6th leaf stage to seed had a negative and significant effect on grain yield. The response of the cultivars was different under stress and non stress conditions. Regarding the existence of significant differences in grain yield between two levels of application and non-application of mycorrhiza under water resources constraints, it is possible to use precise irrigation management and mycorrhiza application in some The cultivars significantly reduced dehydration losses on corn grain yield. The correlation between seed yield with 300 grain weight, number of seeds per row and number of grain rows were positive and significant.
Ali Moshatati; Aydin Khodaei Joghan; Seyed Ataollah Siadat; Seyyed Hashem Mousavi; Mohsen Rezaei
Abstract
Introduction According to statistical yearbook of agriculture in cropping season of 2015-2016, Khuzestan province with wheat area harvested about 535 thousand hectares, production of 1.86 million ton and average yield of 4.4 ton per hectare had the first place between other provinces in the country. ...
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Introduction According to statistical yearbook of agriculture in cropping season of 2015-2016, Khuzestan province with wheat area harvested about 535 thousand hectares, production of 1.86 million ton and average yield of 4.4 ton per hectare had the first place between other provinces in the country. In recent years there was a shortage in water for irrigated wheat farms, therefore irrigated and rain-fed farms have drought stress. In water stress conditions, reduced yield and yield components of wheat. One of the important ways to reduce the negative effect of drought stress on plant is using animal manures and zeolite in the soil. Using animal manure in agricultural soils lead to increase nutrient elements and conserving the soil water. Also using zeolite in soils cause increase soil water and decrease the negative impacts of drought stress on plant. Generally, manure and zeolite contribute to preserving the moisture storage of the soil and to supply the nutrients required by the plant. In this study, the most important aim is to study the effect of cattle manure and zeolite on bread wheat yield and yield components under water stress condition in Ahwaz condition. Materials and methods In order to evaluate wheat response to using cattle manure and zeolite under drought stress condition, a field experiment using split-factorial design based on randomized complete block with three replicates was conducted in research farm of Agricultural Sciences and Natural Resources University of Khuzestan (in 31º N, 48º E, 35 Km north-east of Ahwaz, and 20 m above the sea level) during 2016-2017 cropping season. Experimental factors were three levels of irrigation cutoff (without irrigation cutoff (control), irrigation cutoff from milky-dough stage to physiological maturity and irrigation cutoff from flowering stage to physiological maturity) in main plots and three rates of cattle manure (0, 15 and 30 ton/ha) and three rates of zeolite (0, 6 and 12 ton/ha) in sub plots. Results and discussion Results showed that the effect of irrigation cutoff, cattle manure and zeolite and interaction effect of cattle manure and zeolite were significant of more measured traits. The mean comparison of interaction effect indicated that using 30 ton/ha cattle manure and 12 ton/ha zeolite than control increased grain yield by 70 percent in complete irrigation and 72 percent in irrigation cutoff from milk-dough stage to physiological maturity. Also, in irrigation cutoff from flowering stage to physiological maturity, using 15 ton/ha cattle manure and 12 ton/ha zeolite increased grain yield by 82 percent. Therefore, in regions with irrigation shortage or lack of rainfall in the milky-dough stage, 30 tons per hectare manure and 12 tons per hectare of zeolite are recommended for increasing grain yield. Conclusions Generally, the results showed that drought stress decreased grain yield of wheat but using cattle manure and zeolite decreased the negative impact of drought stress. Means comparison of interaction effect showed that in full irrigation condition could use 30 ton/ ha of cattle manure and 12 ton/ha zeolite to producing the highest grain yield. In irrigation cut-off from milky-dough stage to physiological maturity, using 30 ton/ ha of cattle manure and 12 ton/ha zeolite decreased the effect of drought stress on wheat yield. Also, in areas with irrigation shortage or lack of rainfall at the beginning of flowering stage, 15 tons per hectare of manure and 12 tons per hectare of zeolite are recommended for maintaining grain yield.
Mahdieh Soleymani Sardoo; Mohammad Galavi; Hamid Reza Fanaei; Mahmood Ramroudi
Abstract
Introduction Drought is the biggest factor limiting the production of agricultural products. One of the effective strategies for stress modification is the production and introduction of high yielding and drought tolerant cultivars in combination with low water management methods. Safflower (Carthamus ...
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Introduction Drought is the biggest factor limiting the production of agricultural products. One of the effective strategies for stress modification is the production and introduction of high yielding and drought tolerant cultivars in combination with low water management methods. Safflower (Carthamus tinctorius) is promising due to spring and autumn types and deep roots as a plant resistant to salinity stress and drought stress. The balanced and optimal nutrition of different types of fertilizers, especially micronutrient fertilizers, which have low absorption potential in soil, can be effective in achieving a quality product and balancing environmental and non-living stresses. One of these micronutrient elements is zinc. Irrigation method and suitable planting method depending on the weather conditions in each region are important components for suitable establishment and high yield. With regard to the special conditions of soil and water due to limitations in humidity, low soil organic matter and high soil pH, use of maximum capacity of new plants such as safflower in the field cultivation pattern by applying the correct methods of agricultural management is inevitable. Therefore, with the aim of increasing the productivity, experimental comparing the method of planting and soluble zinc Nano chelate on grain yield and water use efficiency and some agricultural characteristics of safflower under drought stress. Materials and methods In order to evaluation of yield, water productivity and some crop characteristics of safflower in different planting methods with Zn Nano chelate spraying under drought stress a split split- A completely randomized complete block design with three replications was conducted at Agricultural and Natural Resources Research and Education Station of Sistan in 2016-2017. Experimental factors including planting method in two levels (Flat and Furrow) as the main factor, irrigation regime at three levels (irrigation after 45% (control), 65% and 85% of admissible moisture depletion) as subsidiary factor, spraying of zinc Nano chalat in three levels (non spraying zinc, 0.5 and 1 g / liter spraying) as sub-subfactor. The irrigation time was determined according to the soil moisture curve using the Trim model of humidity (1TDR). At the end of the growing season, after leaving side effect from the start and end, 5 plants of the 2 middle rows of each plot were randomly selected and plant height and number of heads per plant were determined and by selecting head 10 random samples of each plot has also calculated the number of seeds per head. Seed 1000 weight was determined with a gravity of 0.01 g. In order to determine the grain yield with respect to the marginal effect, an area equal to 1.6 M2 (square meters) harvested. Water productivity was also calculated by dividing the grain yield per hectare into water consumption per hectare. Data were analyzed using MSTAT-C software and the mean comparison was performed based on Duncan multi-domain test at 5% probability level. Results The irrigation regime and spraying of zinc Nan ochelat was significantly affected by morphological traits, yield, yield components and water use efficiency. number of heads per plant, 1000- seed weight, grain yield and Water use efficiency was under the influence by the planting method. According to the mean comparisons, less irrigation significantly reduced and spraying of Zn Nano chelat increased the studied traits. Grain yield in Flat method increased 29% compared to Furrow method. Irrigation after 45% moisture depletion compared to irrigation after 85% moisture depletion of 61 percent increased grain yield but water use efficiency reduction by 11.5%. The spraying of zinc Nan ochelat with a concentration of 1 g / lit compared to non-spraying grain yield increased by 36 percent and increased water use efficiency by 37% and oil percentage by 12%. Conclusion Grain yield in flat planting method increased compared to furrow planting method. Irrigation after 45 percent moisture depletion compared to irrigation after 85 percent moisture depletion of increased grain yield but water productivity reduction. The spraying of Zinc Nano chelate compared to non-spraying increased grain yield and water productivity. According to the results of flat planting method with spraying of Nano chelate on 1 g. Li-1 under drought stress conditions, it can compensate and eliminate the stress-induced damage for economic production of safflower in Sistan weather conditions.
Taiebe Naderi; Usef Sohrabi
Abstract
Introduction Water deficit stress is an abiotic stress that seriously affects crop production in more parts of the world. Drought stress affects growth and yield of plants in different ways. A wide range of molecular disorders stress can result from the production of reactive and destructive oxygen species ...
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Introduction Water deficit stress is an abiotic stress that seriously affects crop production in more parts of the world. Drought stress affects growth and yield of plants in different ways. A wide range of molecular disorders stress can result from the production of reactive and destructive oxygen species (ROS) that lead to physiological damage to plants under drought. These radicals lead to the reactions that destroy the DNA, fat peroxidation, membrane proteins and Macro proteins including photosynthetic pigments and enzymes. The activity of the anti-oxidant enzymes in plant cells is often increased when the plant is encountered with environmental stress, and from this way the plants would be to reduce the damages due to oxygen free radical production. Considering the increasing drought stress in arid and semi-arid regions and with regard to the importance of providing the food need of the growing population of the world, finding the ways to reduce the effects of drought stress on plant growth and yield is very important. Proper nutrition and supply of required nutrients of the plant through the use of bio-fertilizers along with the chemical fertilizers application, would reduce the use of chemical fertilizers and environmental impacts caused by the excessive use of these fertilizers, because the positive effects of microorganisms in biological fertilizers can be considered as a strategy to reduce the effects of stress on growth and yield of crops. This research was conducted, in order to study the effect of bio and chemical fertilizers application on some physiological traits and grain yield in maize in order to reduce of drought stress effects on grain yield of maize and reduce the chemical fertilizers. Materials and methods This experiment was conducted in research farm of university of Kurdistan in 2012. The research was arranged in split-plot based on a randomized complete block design with three replications. In this experiment, irrigation levels including full irrigation and drought stress in flowering stage allocated to main plots, and fertilizer levels (100% chemical fertilizer, 100% chemical fertilizer + micronutrients, biosuperphosphate + nitroxin, biosuperphosphate + nitroxin + micronutrients, 50% chemical fertilizer + biosuperphosphate, 50% chemical fertilizer + biosopperphosphate + nitroxin and control without fertilizer) were assigned to sub plots. In this study, the Mv500 corn hybrid was sown. The traits studied in present study were: chlorophyll content of leaf, hydrogen peroxide (H2O2), membrane lipid peroxidation, proline content, activity of catalase and peroxidase enzymes. The content of leaf chlorophyll was measured by the Arnon (1949) method, and the amount of hydrogen peroxide was determined by the Loreto and Velikova (2001) method. Measurement of malondialdehyde was performed using the Cakmak and Horst (1991) Method. Proline content was measured by the Bates et al. (1973) method, and the activity of catalase enzyme was determined using the Chance and Maehly (1995) method. The activity of peroxidase enzyme was also measured by the Mac Adam et al. (1992) method. For analyzing variance of data and means comparison, MSTAT-C software was used and the means comparison was done by the Duncan test procedure. Also the charts were drawn using Excel software. Results and discussion The study results showed that water deficit stress increased antioxidant enzymes activities, while bio-fertilizers and micronutrients elements reduced the enzymes activities. Water deficit stress reduced the leaf chlorophyll content, but the proline concentration, malondialdehyde (MDA) and hydrogen peroxide were significantly increased in response to the stress. Application of bio and chemical fertilizers partly prevented from decreasing leaf chlorophyll content and increasing hydrogen peroxide induced by drought stress and could largely moderated the effects of drought stress on grain yield of corn. The lowest grain yield was obtained in non-fertilized condition, which was significantly less than other fertilizer treatments. Consumption of fertilizers caused a significant increase in grain yield in drought stress condition, and although the highest grain yield (7840 kg ha-1) was obtained in corn treated with 100% chemical fertilizer + micronutrient, which significantly had more yield than other treatments, but using bio fertilizers alone or along with 50% chemical fertilizers, significantly increased grain yield under drought stress condition. Conclusion Application of bio and chemical fertilizers could increased resistance of corn plant to drought stress and recovered its yield through supply of nutrients required by the plant. Therefore the correct using fertilizers can be considered as a way for decreasing and moderating the drought stress effects on crop yield.
Bahareh Parsa Motlagh; Parviz Rezvani Moghadam; Reza Ghorbani; Zabihollah Azami Sardooei
Abstract
IntroductionRoselle is an annual plant, Short day, self-pollinated and in terms of weather conditions is sensitive to cold and frost stress (Duke, 2006). Evaluation of water use efficiency is a way to study the water management and its relative values it is appropriate to compare the different crops. ...
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IntroductionRoselle is an annual plant, Short day, self-pollinated and in terms of weather conditions is sensitive to cold and frost stress (Duke, 2006). Evaluation of water use efficiency is a way to study the water management and its relative values it is appropriate to compare the different crops. Water use efficiency is the amount of dry material produced per unit of water and it is usually expressed in kilograms of dry material per cubic meter of water. Severe restriction of water and high costs for water supply and transfer causes that in some cases or regions from an economic perspective, the optimal level of irrigation is less than the required amount to produce maximum yield. The proper management of irrigation and planting for drought resistant plants (Ston and Nofziger, 1993). Due to the beneficial effects of organic and biological fertilizers in agricultural ecosystems, increased vegetative growth, yield components and sepal yield in Abelmoschus esculentus L. (Tiamiyu et al., 2012), Hibiscus cannabinus L. (Basri et al., 2013), Borago officinalis L. (Naghdi Badi et al., 2011; Ahmadabadi et al., 2011), Hibiscus sabdariffa L. (Gendy et al., 2012; Dahmardeh, 2012) have been reported. Nowadays, the cultivation of drought resistant plants has been proposed as a strategy against drought. Roselle is one of the low water requirement and drought resistant, in Southern Iran, which is facing a shortage of irrigation water can be used as a suitable plant in cropping pattern. This research was conducted in Jiroft with the aim of studying the effect of fertilizer resources and different levels of irrigation on yield and water use efficiency of Roselle medicinal plant. Material and methodsA field experiment was conducted at the experiment station of Faculty of Agriculture, University of Jiroft (latitude: 28°40´ N; longitude: 57°44´ E; elevation: 650 m) during 2013 and 2014 growing season. Experimental site was located in southeast of Iran Kerman Province, Jiroft county. The climate of the area is arid and semiarid. A strip plot based on a randomized complete blocks design with three replications was used. Horizontal factor were irrigation regimes at threelevels of 100%, 80% and 60% ofcrop water requirement and fertilizer resourceswere fertilizer resourceswere mycorrhiza, vermicompost, cow manure, chemical fertilizer (NPK) and controlas vertical factor. Plant water requirement is calculated by AGWAT software (Alizadeh and Kamali, 2008). The evaluated traits included number of bolls per plant, sepal dry weight per plant, 100 seed weight, sepal yield, seed yield, biomass yield, sepal water use effeicency, seed water use effeicency and biomass water use effeicency. Harvesting the plant was done on December 1, 2013 in the first year and December 1, 2014 in the second year. Results The average number of bolls showed that the higher number of bolls and weight of dried sepal in irrigation levels of 100% and 80% of plant water requirement in terms of cow manure and vermicompost and the lowest of them in irrigation levels of 60% plant water requirement were belonged to control and mycorrhizal treatments, respectively. Sepal yield at all three levels of irrigation showed increase in the plants treated with manure, vermicompost and chemical compared with mycorrhizal and control treatment and sepal yield in the second year than the first year was higher. The highest seed yield and biomass yield was related to cow manure, vermicompost and chemical fertilizers that was observed in irrigation level of 100% and then 80% water requirement and the lowest of it was belonged to control and mycorrhizal treatment and irrigation level of 60%, respectively. During the two years study, sepal water use efficiency in the second year with the amount of 116.90 g.m-2 of water was significantly higher than the first year with the amount of 102.99 g.m-³. The average comparison in result of applying different levels of irrigation showed that the highest and lowest levels of seed water use efficiency was observed in 60% irrigation treatment and irrigation level of 100%. Rezapour et al (2011), by investigating the effect of drought stress and different amounts of sulfur fertilizer on Nigella sativa L. Similar results observedin Roselle (Hibiscus sabdariffa L.) (Gendy et al., 2012; Dahmardeh, 2012), and Okra (Abelmoschus esculentus L.) (Tiamiyu et al., 2012). ConclusionBased on two years data combined analysis, the results indicated that fertilizer resources and irrigation regimes had significant effect on the most morphological and agricultural traits. The interaction effect of fertilizer resources and irrigation regimes had a significant effect on calyx yield, 100 seed weight and sepal water use efficiency . The highest calyx yield (1248 kg.ha-1) was obtained at 100% crop water requirement cow manure treatment and the lowest calyx yield (510 kg.ha-1) was obtained at 60% crop water requirement control treatments. According to the results, it can be concluded that 80% crop water requirement treatment with the use of cow manure, vermicompost and chemical fertilizer are desirable treatments in roselle production.
Kamran Parvanak
Abstract
IntroudationSalvia sahendica is a perennial native odorant plant of Iran with a right stem, crustal and about 90-40 cm height. Due to the importance of the use of Salvia sahendica in various pharmaceutical, food and sanitary industries, and because of its potential for cultivation in stressful climates, ...
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IntroudationSalvia sahendica is a perennial native odorant plant of Iran with a right stem, crustal and about 90-40 cm height. Due to the importance of the use of Salvia sahendica in various pharmaceutical, food and sanitary industries, and because of its potential for cultivation in stressful climates, this plant has attentions to cultivate in low-yielding lands. Until now, there is not a comprehensive study on the response of Salvia sahendica to drought stress. Therefore, in order to evaluate the possibility of production and development of its cultivation under drought stress conditions, this research was carried to investigate the effects of drought stress on some physiological parameters, percentage and yield of essential oil of Salvia sahendica and determining the tolerance threshold of this plant to stress in 1395 in field conditions. Material and MethodsThis experiment was conducted at the research farm of Mobarakeh steel complex which located at 40th kilometers of southwest of Isfahan, at latitude of 32˚ 21′ northern and longitude of 51˚ 27′ eastern. After field preparation, the plants were cultivated in plots with size of 1.5 × 1.5m by 50 × 50 cm spacing in a randomized complete block design with three replicates and 9 plants per replicate. At the beginning of planting, all plots were irrigated three times a week for two weeks until the plants were established. Then, the effect of various irrigation intervals including 4 (as control, which is traditionally the optimum irrigation rate of plant in studied area), 8, 12 and 16 days intervals were applied. At the end of the summer, a sample was taken from the cultivated plant. The plants were fractioned to roots and shoots and some physiological and biochemical indices including, relative water content of leaves (RWC), water potential of leaves, total chlorophyll and chlorophyll a and b, proline and soluble sugars contents, electrolyte leakage, the essential oil percentage and yield were determined. Statistical analysis was performed on the data using MSTAT-C software at 5% level and the correlation between traits was determined by SPSS software. Results The results of analysis of variance showed that the effects of different levels of irrigation intervals on water potential of leaves, relative water content of leaves, soluble sugars, electrolyte leakage, percentage and essential oil yield were discriminated at 1% statistical level while on proline and total chlorophyll, chlorophyll a and b contents at 5%. Based on the results of the comparison of the mean, by increasing irrigation interval from 4 to 8 and 12 days, the differences in the means of all investigated parameters were not significant and only in 16 days irrigation interval the noted parameters differed significantly(pr<0.05). The highest amount of RWC (95%), chlorophyll a, b and total chlorophyll were 2.47, 1.32, and 0.98 mg.g-1 respectively in control treatment. The highest water potential of leaves (-1.78 MPa), proline accumulation (3.1 mg.g-1) and electrolyte leakage (57.7%) were observed in16- day irrigation interval. Maximum amount of soluble sugar, percentage and essential oil yield by the mean of 2.55 mg.g-1, 0.3% and 14.3 kg.ha-1 respectively were obtained in the 12-day irrigation interval. The correlation of traits showed a negative relationship between chlorophyll a, chlorophyll b with proline, soluble sugars, percentage and essential oil yield. Conclusion By considering that non-significant differences were observed in stress resistance indices of this plant up to 12-days interval in comparison with control, it can be concluded with 95% confidence that an optimal irrigation interval for using of this plant in areas arid and semi-arid regions is 12 days irrigation interval, which saves irrigation water. Also, the results of this study showed that Salvia sahendica resisted to water stress by increasing accumulation of proline and soluble sugars (osmotic regulation). Therefore, the accumulation of proline and soluble sugars can be considered as a sensitive indicator for determining the degree of leaf turgidity. Also, in order to produce the highest amount of essential oil from Salvia sahendica, the mild stress (12-day irrigation) can be used.
Shilan Davodi; Bahram Mir Shekari; Touraj Mir Mahmoodi; Farhad Farahvash; Saman Yazdan Seta
Abstract
IntroductionSunflower is one of the major and most important non-conventional oilseed crops in the world due to its excellent oil quality. Though sunflower is known as a drought tolerant crop or grown under dry land conditions, substantial yield increases are obtained with frequent irrigation. Drought ...
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IntroductionSunflower is one of the major and most important non-conventional oilseed crops in the world due to its excellent oil quality. Though sunflower is known as a drought tolerant crop or grown under dry land conditions, substantial yield increases are obtained with frequent irrigation. Drought stress damages the thylakoid membrane, disturb its functions, and ultimately decrease Photosynthesis and crop. Drought stress usually induces the accumulation of reactive oxygen species (ROS), which cause oxidative damage to plants. If not effectively and rapidly removed from plants, ROS can damage a wide range of cellular macromolecules such as lipids, enzymes and DNA. Plants can protect themselves against oxidative damage by antioxidant system including antioxidative enzymes and nonenzymatic compounds. Materials and Methods This study was done in agricultural research farm of the Islamic Azad University, mahabad Branch in south of West Azerbaijan, Iran during 2014 to 2016. The experiment was laid out in a split plot on the basis of randomized complete block design with three replications. The main plots included two irrigation regimes (Irrigation after 50 mm evaporation from class A pan and irrigation after 100 mm evaporation from class A pan, as control and water stress conditions, respectively) and the sub plots included three seed praiming with salicylic acid (0 (control), 100 and 200ppm) and seed praiming with ascorbic acid (0 (control), 50 and 100ppm). Common Sunflower seeds (cv. Euroflore) were soaked for 6 h in salicylic acid and ascorbic acid solutions. In this research superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), Di-tyrosine (D.T), Malondialdehyde (MDA), grain yield and oil perecentage was measured.Finally all data were analyzed by SAS. 9.2 statistical software and the means were compared by Duncan′s Multiple Range Test at the 5% probability level by MSTAT-C. Result and discussion Analysis of variance showed, there was significant difference between irrigation levels in terms of effect on all traits. Effect of salicylic acid and salicylic acid and ascorbic acid interaction on all traits was significant except of malondialdehyde. The effect of ascorbic acid and salicylic acid whit irrigation levels interaction on all traits except of amount of D-tyrosine was significant. Finally interaction of irrigation levels and ascorbic acid on the proline, catalase and malondialdehyde were significant. In this study water deficit increased amount of proline, catalase, superoxide dismutase, glutathione peroxidase, D-tyrosine and Malondialdehyde by 9.75, 19.18, 36.83, 14.36,17.51 23.97 and 25.10 percent, and decreased amount of grain yield and oil percentage by 51.26 and 24.48% compared with control treatment. Also priming with salicylic acid and ascorbic acid, individually or combined together increased amount of proline, catalase and glutathione peroxidase and D-tyrosine, and decreased amount of malondialdehyde compared with control treatment. Furthermore the highest grain yield (2.72 t/ha) and oil content (52.09) were belonged 200ppm of salicylic acid with 100 ppm of ascorbic acid, Also, level of 200ppm of salicylic acid and 100ppm of ascorbic acid increased the activity of proline, catalase, superoxide dismutase and glutathione peroxidase and D-tyrosine enzymes, grain yield and oil percent by 9.21, 50.35, 54.25, 49.18,48.24, 36.68 and 39.31percent compared to control treatment, respectively. Conclusions The present study indicated that drought stress increased oxidative damage, membrane lipid peroxidation and MDA content as well as antioxidant enzymes (SOD, CAT and GPX) activities, proline level and oil percentage but decresed grain yield in sunflower, nevertheless seeds priming with salsilic (especially 200 ppm) and ascorbic acid (especially 100 ppm) induced protection against drought stress via maintenance of membrane integrity by decline in MDA content and more increase in antioxidant enzymes activities (especially SOD) as well as prolin accumulation, grain yield and and oil percentage. Our results showed priming with salicylic acid and ascorbic acid it can induce drought tolerance in sunflower and improve grain yield and oil content in underwater stress conditions.
Hamideh Ghafari; Mahmoud Reza Tadayon
Abstract
Introduction Drought stress has become the major limitation factor on plant yield at global scale. It is due to the current environmental changes not only in dry areas but also in temperate ones. Deficit irrigation allows to the plants receive water lower than request. Sugar beet production requires ...
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Introduction Drought stress has become the major limitation factor on plant yield at global scale. It is due to the current environmental changes not only in dry areas but also in temperate ones. Deficit irrigation allows to the plants receive water lower than request. Sugar beet production requires supplementary irrigation in sugar beet producing areas such Mediterranean regions, but recently drought stress has restricted sugar beet cultivation in these areas. In arid and semi-arid regions, sugar beet production is limited by insufficient rainfall or restricted the availability of irrigation water. Breeding new cultivar for drought tolerance, developing new irrigation and soil management techniques and innovating new cultural practices may contribute to improve yield and quality of sugar beet under drought conditions. Sugar beet is one of the most important crops. It is also well recognized that drought stress is the main restrictive factor for sugar beet yield. However, the response of sugar beet to drought stress has been insufficiently studied. Jasmonic acid is a member of plant growth regulators named jasmonates which are important cellular regulators involved in several developmental processes such as seed germination, root growth, fertility, fruit ripening and senescence. Most of the plant parts contain jasmonates and the highest concentration appears to be present in reproductive tissues whereas much lower levels are found in roots and mature leaves. Till now it is considered that jasmonates particularly methyl esters of JA (Me-JA) as a chemical stress agent mimicking the effect of that appear in response to external stress factors inducing senescence. Materials and methods To explore the germination mechanism of drought-stressed sugar beet improved by exogenous jasmonic acid, and provide a theoretical basis to sugar beet direct sowing technology for water deficit and the effects of soaking with jasmonic acid on germination status, an experiment was conducted in factorial randomized complete design with four replications in laboratory, Faculty of Agriculture, University of Shahrekord in 2016. In this experiment, treatments included five levels of drought treatments (distilled water,-0/2,-0/6,-1 and-1/4 MPa with PEG) and seed soaking with jasmonic acid (0 (control), 5 and 10 µM for 2 days. Germination percentage and rate, shoot and length, shoot weight, mean germination time, coefficient of velocity of germination, relative germination, allometry coefficient, seed length and weight vigor index were measured. Results and discussion The results showed that drought stress and jasmonic acid on germination indexes including germination percent and rate, shoot and root length, shoot weight, coefficient of velocity of germination, relative germination, allometry coefficient and seed length and weight vigor index significantly decreased under drought stress, while, mean germination time increased. Drought stress in 1/4 MPa level decreased germination percentage and rate, shoot and root length, shoot weight 90, 84, 49, 44 and 33 percent as compared with control, respectively. In other hand, soaking with exogenous jasmonic acid improved all of germination indexes, while mean germination time decreased under drought stress. Moreover, interaction effect drought and jasmonic acid on germination indexes showed 5 µM jasmonic acid had highest germination percent and rate, shoot length and weight, coefficient of velocity of germination, relative germination, and seed length and weight vigor index. The highest germination percentage and rate was detected when 5 µM jasmonic acid under non-stress that increased 21% as compared with control, while the lowest was detected when pre-soaking water under 1/4 MPa. Also, highest increase in mean germination time was recorded under 1/4 MPa with pre-soaking water, whereas, the lowest was measured under non-stress with 5 and 10 µM jasmonic acid. To conclude, soaking with 5 µM jasmonic acid improved drought tolerance in sugar beet.
Siavash Heshmati; Gholam Abbas Akbari; Elias Soltani; Majid Amini Dehaghi
Abstract
IntroductionDrought and salinity are major environmental factors that influence crop productivity worldwide .Plants are normally subjected to a combination of various types of abiotic stresses in nature, such as the combined effects of drought and salinity .Studies have revealed that the physiological ...
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IntroductionDrought and salinity are major environmental factors that influence crop productivity worldwide .Plants are normally subjected to a combination of various types of abiotic stresses in nature, such as the combined effects of drought and salinity .Studies have revealed that the physiological and biochemical responses of plants to the interaction of drought and salinity are unique and cannot be directly extrapolated from the responses to the two stresses individually.Storage of orthodox seeds for prolonged period induces their deterioration leading ultimately to loss of their viability. The rate of seed deterioration varies among plant species and seed lots, but high moisture content and high temperature accelerate this process. During long-term storage, all seeds undergo aging processes leading to deterioration in seed quality, especially in the humid tropical regions. However, the rate of seed deterioration can vary among various plant species. When aged seeds are sown, they show decreased viability, lower germinability performance, and produce weak seedlings which could not manage to survive in their habitat. Seed priming (osmoconditioning) has been successfully demonstrated to improve seed germination and seedling establishment for many field crops.The beneficial effects of priming have also been demonstrated on germination and seed emergence, as well as seedling establishment of many crops, particularly under drought and salt stress.Use of chemical compounds as priming agents has been found to improve plant tolerancesignificantly in various crop and non-crop species against a range of different individually applied abiotic stresses.Melatonin, due to its pleiotropic effects can play important roles in improving plant tolerance to adverse conditions.Safflower (Carthamus tinctorius L.) is one of the prospective oilseed crops because it yields about 32–40 % seed oil. However, due to its considerable salt resistance than commonly grown oilseed crops, it is cultivated in arid and semi-arid regions where soil salinity is one of the major threats to agriculture.Drought is very unpredictable among abiotic stresses in terms to occurrence, severity, timing. and duration and safflower can be a promising alternate crop in dryland agro-ecosystems due to its growth potential under water stress without a substantial reduction of oil and seed yields. Safflower cultivation constitutes a more profitable crop for the farmers in some countries, compared to other conventional crops such as barley, lentil, and chickpea.The fact that safflower can overcome environmental stresses such as extreme temperatures, drought, and salinity has facilitated its expansion in areas around the world, where soil and climatic restrictions have impeded the cultivation of conventional food and cash crops.In particular, safflower has demonstrated drought resistance with a slight decrease in crop yield and significant stability in water use efficiency Materials and methods In order to study the effect of seed priming of naturally aged seed by melatonin on seedling emergence and growth characteristic of safflower, three experiments were conducted at seed science technology laboratory, greenhouse and research farm of Aburaihan Campus, the University of Tehran in 2017. The experimental design for all experiment was factorial in completely randomized design (laboratory) and randomized complete block design (research farm and greenhouse) with 4 replicates. The main treatments that common between experiments consist of seed quality (1-naturally aged seed 2- new seed) and seed priming (1-without priming 2- hydropriming 3- Melatonin 0.1 mM 4- Melatonin 0.5 mM). Soil water was determined based on soil moisture release curve, which indicates the relationship between soil water potential andsoil moisture content. Prior to the pot experiments, three samples of wet soil (wet soil = drysoil ? soil moisture content) were dried and soil moisture content at the beginning of experiment was determined.Then pots were equally filled with wet soil. Two pots were considered as references and were weighted each day: one for drought stress and one for other abiotic stresses. The soil moisture content could be obtainable after weighing and it was possible to calculate soil water potential from soil moisture release curve. Results and discussionThe results of this research indicated that the highest percentage of seedling emergence of naturally aged seed obtained by hydropriming and melatonin priming at 0.1 mM by %54.50 and %57.50 that increased the seedling emergence up to %39.74 and %47 respectively, in comparison to control in the farm condition. Also, the results showed that highest percentage of seedling emergence under drought condition belong to melatonin priming at 0.1 mM concentration that increased the seedling emergence up to %154 in comparison to control in the greenhouse condition. The results of this experiment indicated melatonin priming at 0.1 mM concentration led to the highest rate and percentage of seedling emergence under salinity and combination of salinity and drought condition while melatonin priming at 0.5 mM concentration has decreased the rate of seedling emergence.ConclusionsIn general, using of seed priming as a cost-effective method also hydropriming and melatonin priming could enhance the seed quality for growth under salinity and drought conditions.
Vahid Atlassi Pak; Omid Bahmani; Samira Afshin Nik
Abstract
Background and Objectives Plants are often subjected to water deficit and soil salinity in arid and semiarid regins. Water deficit and salinity threaten crop productivity as both stresses reduced the soil water potential. In the natural invironment drought and salinity frequently combined. Understanding ...
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Background and Objectives Plants are often subjected to water deficit and soil salinity in arid and semiarid regins. Water deficit and salinity threaten crop productivity as both stresses reduced the soil water potential. In the natural invironment drought and salinity frequently combined. Understanding how plants responds to water deficit, salt and co-occurring stresses can play a major role to improving the toleranc of crops to both water deficit and salinity. Salinity may cause ions imbalances, due to the competition of Na+ with nutritons such as K+. Reduced transpiration rates due to water deficit reduces the nutrient uptake and transport. Deficit irrigation with fresh water can increase water use efficiency without significantly decreasing yield. Several studies have focused on effect of water deficit and salinity on nutrients uptake but there is still no information on the effect of these conditions on ions relations and water use efficiency. The aim of this study was to investigate the effects of salinity and water deficit on ion distribution in different tissues and water use efficiency of bread wheat cultivars with contrasting of sodium concentration. Materials and methods In this study, ions distribution and grain water use efficiency (WUE) of two bread wheat cultivars (Arg and Tajan) with contrasting of sodium concentration to different irrigation regimes (full irrigation, 80 and 70 percent of water requirement) and different salinity levels (0 and 150 mM NaCl) in a greenhouse experiment with three replications were evaluated. Treatments were imposed when the leaf 4 was fully expanded. For sodium and potassium analysis, at 7 weeks after treatments, plants were completely harvested from pots, washed and divided into required parts. Roots, flag leaf sheath, flag leaf blade and leaf 3 blade used for determining Na+ and K+ concentrations. The remaining plants were left to grow until physiological maturity. Plants were harvested after 16 weeks to measure yield and root biomass. Results and discussion Whole plant sodium concentration of cultivars was significantly increased under salt stress. In salt treatment, the tissues Na+ and K+ concentration was significantly higher in Arg than Tajan. Under salt stress, water deficit caused a reduction in Na+ concentration in all tissues. Sodium uptake by root was similar in cultivars but Tajan maintained lower Na+ concentration in shoot tissues under salinity. Differences in sodium concentration were found in flag leaf blade in cultivars. Genotypic differences in the rate of sodium transfer from the root to shoot are caused to occure genotypic differences in leaves Na+ concentration. Tajan had more control of ion transport from root to shoot. Under salt stress, K+ concentration was not affected by water deficit in tissues. Arg maintained higher K+ concentration with K+/Na+ ratios in flag leaf blade than Tajan cultivare. Root biomass decreased in cultivars at 150 mM NaCl whereas don’t affected by deficit irrigation. An NaCl concentration of 150 mM was found suitable to identify genetic variation in root wheat genotypes. NaCl decreased grain yield and grain WUE in salt stress conditions and Tajan showed more decreases from this aspect. It seems that, a lower decrease in grain WUE in Arg, is due to greater tissue tolerance. Conclusions: Differences in Na+ concentration under salinity and drought, mainly occur in the youngest leaf blade between cultivars and lower sodium transfer from the root to shoot, lower sodium accumulation in younger leaves and higher K+/Na+ ratios can be important in stabilizing wheat yield and grain water productivity. Tajan have a more resistance to osmotic stress than Arg and tissue tolerance in Arg was greater than Tajan cultivare. Cultivars that maintained low concentration of Na+ in shoots and have a greater degree of tissue tolerance, in regions with poorer quality irrigation water, have more water productivity and thus this is an imperative to develop cultivars with above mentioned characteristics in soils with higher salt and limited water.
Mehdi Karimi
Abstract
IntroductionThere is an increasing trend in salt affected lands and it plays a crucial role for reduced crop production. Associated with Social and economic dimentions such as employment losses and environmental degradation (Butcher et al., 2016), it is estimated that annual losses of yield due to salt ...
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IntroductionThere is an increasing trend in salt affected lands and it plays a crucial role for reduced crop production. Associated with Social and economic dimentions such as employment losses and environmental degradation (Butcher et al., 2016), it is estimated that annual losses of yield due to salt induced land degradation is US$ 27.3 billion globally (Qadir et al., 2014). In addition, it is well documented that application of chemical fertilizers usually improve plant performance under saline conditons but results in plant fertilizer requirement under salt affected soils are contrary. While there is little evidence of yield benefits due to application of fertilizers in salinized fields at rates beyond optimal in non-saline conditions, there is enough evidence indicating that soil salinity does not affect or decrease plant fertilizer needs (Hanson, 2006). These contradictory results can be attributed to the types of experiments (field, greenhouse or laboratory), composition of the saline substrate, studies conducted over the short term vs. the long term and many other differences in experimental conditions (Grattan and Grieve, 1999).The salinity stress may modify the Fe fertilizer management for wheat production under arid and semiarid conditions of Yazd peovince with wide range of irrigation water qualities. Accordingly, the objectives of this field study were to (a) evaluate the interactions between Fe nutrition and the salinity of irrigation water and their effects on wheat growth and (b) test the possibility of wheat improvement at saline conditions by applying higher levels of Fe fertilizer. Materials and methodsA field experiment was conducted on wheat at Sadooq Salinity Research Station, Ashkezar, Yazd, Iran. The soil at the experimental site was calcareous with 30.92% total nutrient value, sandy loam texture, pH 8.06 and 0.22 % organic carbon. Mean annual temperatue is 18°C and precipitation is 70 mm. The treatments, four potassium sulphate application rates (0, 100, 200 and 300 kg ha-1) and three irrigation water qualities (1.88, 7.22 , 14.16 dS/m), arranged in a randomized block, split plot design with three repelications. Consisting 12 rows of wheat, each field plot was 3*5 m. All plots received common agricultural practices including tillage and fertilizer application. Rgarding typical recommendations and guidelines for this region and soil type (Balali et al., 2000: Moshiri et al., 2015), all fertilizers, except urea that applied in 4 splits, were soil-applied before plnating and included 100 kg ha-1 triple superphosphate, 40 kg ha-1 ZnSO4, 40 kg ha-1 MnSO4 and 20 kg ha-1 CuSO4. To model the relationship between plant properties and irrigation water salinity, the data were subjected to different regression models at the probability level of 0.01 and 0.05 with the help of the Sigmaplot software. The analysis of variance for different parameters was done following ANOVA technique. When F was significant at p ≤ 0.05 level, treatment means were separated using DMRT. Results and discussion The results showed that increasing irrigation water salinity to 7.22 dS/m did not significantly affect wheat graine yield. This is due to the positive effect of salinity on 1000 seed weight and harvesting index. At the same time, the results showed 50% decrease in wheat grain and straw yield due to the increase in the salinity of irrigation water from 1.88 to 14.16 dS/m. The heighest graine yield for treatments irrigated with irrigation water salinity of 1.88, 7.22 and 14.16 dS/m was obtained from application of 40, 20 and 0 kgha-1 FeSO4, respectively. Overall, it was concluded that salinity stress beyond salt tolerance decreased wheat requirement to iron sulphate fertilizer.
Hadi Mehdikhani; Ebrahim Izadi Darbandi; Mehdi Rastgoo; Mohammad Kafi
Abstract
Introduction Salinity is one of the major environmental factors which limits plants productivity and it is considered acting as the main source of yield reduction. The adverse effects of soil salinity in plants growth include ions toxicity, ...
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Introduction Salinity is one of the major environmental factors which limits plants productivity and it is considered acting as the main source of yield reduction. The adverse effects of soil salinity in plants growth include ions toxicity, osmotic stress, nutritional dis-orders, and it also hampers the water uptake by the seeds and plants. Salt tolerance in plants is a multifarious phenomenon involving a variety of changes at molecular, organelle, cellular, tissue as well as whole plant level. In addition, salt tolerant plants show a range of adaptations not only in morphological or structural features but also in metabolic and physiological processes that enable them to survive under extreme saline environments. Bassia scoparia is a dicotyledonous annual herb and belongs to the Amaranthaceae family. Genetic diversity and resistance to drought stress of this plant has made it widely scattered in different regions which contains highly genetic diversity and great potential as fodder and can grow on salty, drought affected areas. The objectives of this study were to the effect of salt stress on growth response and some morphological and physiological traits of Bassia. Materials and methods In order to study the effect of salinity on morphological and physiological traits of Bassia (Bassia scoparia L.) an experiment was conducted in the randomized complete block design with four replications in 2014 at the Research Greenhouse in the Faculty of Agriculture, Ferdowsi University of Mashhad. Treatments included different levels of salinity (10, 16, 22, 28 and 34 dS.m-1 and non-saline water (1.4 dS.m-1) as the control.). The seeds were planted in plastic pots (with 23 cm diameter), filled with a mixture of leaf soil, sand and loam soil (1:1:1; v/v). Salt solution was added to each pot containing sodium chloride, magnesium sulfate, magnesium chloride and calcium chloride in a ratio of 6: 2: 1: 1 with irrigation water after complete plant establishment. The type and ratio of solutes used in the saline solution is simulated based on Caspian Sea water and several saline rivers in Iran. Irrigation with saline water until complete seedling establishment (plant height were about 10 cm) was followed by non-saline water. After that, until the end of experiment (56 days after emergence, when plant height in control treatment was about 50 cm) irrigation was done with the desired salinity water treatments. At the end of the experiment after plants harvesting, different morphological traits of plants including plant height, fresh and dry weights of shoots, number of lateral branches, leaf area index were measured on all 5 plants in pots. One week before planting, physiological traits including chlorophyll index, stomatal conductance, membrane stability index, relative leaf water content, ash %, organic matter %, potassium, sodium and K/Na. photosynthesis, transpiration were measured, and chlorophyll fluorescence indices including maximum fluorescence (Fm), minimum fluorescence (Fo), variable fluorescence (Fv) and maximum quantum yield (Fv / Fm) were measured in two vegetative (35 days after emergence and when plant height was approximately was 30 cm) and reproductive stages (49 days after emergence when plant height was about 45 to 50 cm). The youngest developed leaves were used to measuring physiological traits. Analysis of variance and comparison of means using duncan's multiple range test at the 5% level of probability and stepwise regression analysis to determine relative share of traits were performed using SAS 9.1 software. Results and Discussion The results showed that salt stress was significantly decreased plant height, leaf area, dry matter, number of lateral branches, Fo at the vegetative stage, stomata conductance, transpiration, ash %, organic matter %, potassium, sodium and K/Na. That there was no significant and positive correlation between fresh and dry weight with physiological traits and nutrients. Based on step-wise regression analysis, three traits of the number of lateral branches, leaf area and dry matter were only traits that were entered to the model and were justified 90 % of the dry weight changes. No relationship was observed between fresh and dry weight with physiological traits and nutrients. Physiological traits were less affected by salinity in compared to morphological traits. According to the results, due to the saline nature of Bassia, most of morphological and physiological traits and its growth were better than non-stress conditions even in low and medium salinity. Conclusion The results confirmed the reports of high tolerance of Bassia to salinity, indicating that the use of non-destructive and physiological indices, especially chlorophyll fluorescence index, can be a reliable and rapid indicator in assessing plant salinity response. On the other hand, high tolerance of Bassia to salinity, allowing the use of saline water in the production of this plant as an economic plant or in green areas, is an important and determinant trait in its ability to compete with crops in saline soils. When it is present as an invasive plant.
Somayeh Hasani; Seraleh Galeshi; Ebrahim Zeinali; Benyamin Torabi; Mohamad Khadempir
Abstract
Introduction Due to inappropriate irrigation methods, poor drainage in the fields and also warming the planet, flood stress has become an important stress in recent years for crops. On the other hand, due to the importance of soybean in supplying oil and animal feed, sufficient information is available ...
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Introduction Due to inappropriate irrigation methods, poor drainage in the fields and also warming the planet, flood stress has become an important stress in recent years for crops. On the other hand, due to the importance of soybean in supplying oil and animal feed, sufficient information is available on soybean flooding stress tolerant cultivars or lines in Iran Which have a high yield under flooding stress conditions, Does not exist. Therefore, this experiment In order to select soybean genotypes tolerant to flood stress in the country based on seed yield, seed yield components and tolerance and stress resistance indices. Materials and methods This experiment was conducted as factorial in a completely randomized design with 3 replications and two factors: 1- flooding stress (no flooding stress and 15 days flooding stress) and 2- cultivars (31 soybeans cultivar and lines). Time of action flooding stress was 5-leaf stage (V5). In this experiment, seed yield and biological yield of soybeans, components yield of soybean (number of pods per plant, number of seeds per pod, 100 seed weight), and tolerance and stress resistance indices were measured and calculated. Data analysis was done using SAS software and drawings of diagrams and forms with Excel software. Results and discussion The results of this experiment showed that flooding stress significantly reduces the seed yield and biological yield of soybeans, So that the seed yield for 15 days of flooding stress decreased from 40.6 to 61.7% and biological yields decreased by 17% to 44% during 15 days of flooding stress. The highest seed yield after 15 days of flooding in 326 and 827 cultivars, and the lowest seed yield after 15 days of flooding was observed in cultivars 114 and 937. The results of this experiment also showed that GMP, MP and STI indices have a very high correlation with seed yield under stress conditions and these three indicators can be used to select high yield cultivars under stress and non stress conditions. Based on SSI, STI, MP and GMP indices cultivars 859, 827 and 326 are the most resistant cultivars among the cultivars studied in this experiment. Acknowledgements In general, according to the results of this experiment, soybean varieties do not differ much in terms of response to flood stress and among 31 soybean varieties studied three varietie of 859, 827 and 326 have a good tolerance to flooding stress have and in conditions without flooding stress and in flooding stress conditions seed yield is acceptable.
Volume 12, Issue 4 , January 2020, Pages 1340-1340
