Sajad Esapour Nakhjiri; Majid Ashouri; Seyyed Mostafa Sadeghi; Naser Mohammadian Roshan
Abstract
Introduction
Due to the continuous water shortages in rice cultivation areas, unbalanced use of nitrogen chemical fertilizers, the need to pay less attention to the use of water in rice cultivation and balance in the use of chemical fertilizers in saving and preventing water loss is important. Periodic ...
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Introduction
Due to the continuous water shortages in rice cultivation areas, unbalanced use of nitrogen chemical fertilizers, the need to pay less attention to the use of water in rice cultivation and balance in the use of chemical fertilizers in saving and preventing water loss is important. Periodic irrigation has been introduced as an important research finding to reduce water consumption and increase water use efficiency in paddy lands. As water stress increases, the uptake of nitrogen, phosphorus and potassium decreases.
Materials and methods
Therefore, this study conducted for evaluation the effects of different irrigation regimes and N fertilizer on yield, and the content of micronutrients in brown and white rice was conducted in Rashat during cropping season of 2016-2017 and 2017-2018 in Rasht. Experiment was arranged in split split plot based on completely randomized block design with 3 replications in which water regimes were main factor included continuous submergence, 7 and 15 day interval irrigation and nitrogen fertilizer levels were sub factor included 50 , 75 , and 100 kg ha-1 and cultivars were sub sub factor included Gilanh and Hashemi. Before conducting the composite data analysis, Bartlett's test was used to ensure the homogeneity of experimental error variance. Analysis of variance and statistical calculations were performed using SAS software version 9.1 and the mean of the studied traits were compared using Duncan test at 5% probability level. In order to check the normality of the data, the normality test in SAS program was used.
Results and discussion
The results showed that by increasing the irrigation interval, paddy yield decreased, while application of 75 and 100 kg ha-1 nitrogen fertilizer increased paddy yield in all three irrigation levels compared to the level of 50 kg ha-1 nitrogen fertilizer. There was a significant effect (at the level of one percent probability) between the treatment of irrigation regimes, nitrogen fertilizer and cultivar on brown and white rice and macro elements. The highest yield of rice for the Gilaneh variety was achieved under flooded irrigation treatment combined with the application of 100 kg ha-1 of nitrogen fertilizer, resulting in 12.4 T ha-1 in 2017 and 4.05 T ha-1 in 2018. Increasing the irrigation interval also increased the content of macro elements in brown and white rice. The highest protein content in brown rice was recorded at an average of 9.45% from the flooded irrigation treatment, with the application of 100 kg ha-1 of nitrogen fertilizer, specifically in the native Hashemi variety. The highest phosphorus in brown rice in the treatment of 7 days of irrigation, 75 kg of nitrogen per hectare in Gilaneh cultivar with a rate of 0.303% and the lowest amount in the treatment of 7 days of irrigation with 50 kg of nitrogen and in Gilaneh cultivar with 0.056 percent and the highest percentage of potassium in white rice in the treatment of 14 days of irrigation, 50 kg of nitrogen per hectare and in Hashemi cultivar with the amount of 0.246 percent and the lowest amount in the flooded treatment with Consumption of 50 kg of nitrogen in Hashemi cultivar was 0.143%.
Conclusion
The results of this study showed that the application of nitrogen fertilizer has the ability to increase yield and yield components at all three irrigation levels and in both Hashemi and Gilaneh cultivars. In all three levels of irrigation in this study with increasing nitrogen fertilizer application with increasing vegetative growth, increasing the number of spikes per square meter, number of seeds per spike and paddy yield was observed. Consumption of 100 kg ha-1 of nitrogen fertilizer resulted in the highest yield of paddy in both cultivars and all three irrigation levels.
Khadijeh Sourazar; Raouf Seyed Sharifi
Abstract
Introduction
Salinity is a global challenge issue that is drastically reducing agricultural production. More than 800 million hectares of agricultural land suffer from soil salinity. Intense salinity stress may cause accelerated aging enzymatic and metabolic disorders of the plant. Salinity stress leads ...
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Introduction
Salinity is a global challenge issue that is drastically reducing agricultural production. More than 800 million hectares of agricultural land suffer from soil salinity. Intense salinity stress may cause accelerated aging enzymatic and metabolic disorders of the plant. Salinity stress leads to plant death by reducing photosynthetic carbon dioxide uptake and electron transport activity, chlorophyll degradation, reactive oxygen species (ROS) accumulation, and membrane damage. Methanol is one of the simplest alcohols, which is oxidized in the form of formaldehyde and carbon dioxide in the plant, and is produced in the form of amino acids (serine and methionine) and carbohydrates in various tissues of three-carbon plants (C3). Plants treated with methanol can increase their net absorption rate. Vermicompost provides a great potential to enhance crop productivity besides protecting soil health and environmental sustainability. Its application also enhances the physico-chemical, as well as the organic properties of the soil. Vermicompost is a solid product of organic residues enriched with earthworms and other micro-faunas that provide a significant source of growth regulator hormones, degrading enzymes (such as chitinase, cellulase, lipase, amylase, and proteases), and some essential vitamins. The aim of this study was the investigation the effects of vermicompost and methanol on the activity of antioxidant enzymes, compatible osmolytes and some traits of triticale under saline conditions.
Materials and methods
An experiment was conducted as factorial based on randomized complete block design with three replications in greenhouse research of Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili during 2022. Experimental factors were included salinity in three levels (no salinity as control, salinity 50 and 100 mM by NaCl), application of vermicompost at two levels (without vermicompost as control and application of vermicompost) and methanol foliar application in three levels (foliar application with water as control, foliar application 15 and 30% volume). "Sanabad" cultivar was used. The seeds were placed in a cold incubator (model IKH.RI90) for 12 days at 2°C for vernalization. The amount of vermicompost used in this experiment was 6 tons per hectare (equivalent to 83.08 g.pot-1). In this study, activity of CAT, PPO, POD, soluble sugar, protein, proline, MDA, H2O2, EC, RWC and grain yield were investigated. Electrical conductivity (EC) values were measured using an electrical-conductivity meter (Mi 180 Bench Meter model). The activity of antioxidant enzymes (CAT, PPO and POD) by the method of Sudhakar (Sudhakar et al., 2001), the total protein content of the flag leaf by the Bradford method (Bradford, 1976), the content of soluble sugars by method of Dubios (Dubios et al., 1956), malondialdehyde content by Stewart and Beweley's method (Stewart and Beweley, 1980), proline content by Bates et al.'s method (Bates et al., 1973) and hydrogen peroxide content was measured by the method of Alexieva et al. (Alexieva et al., 2001) on the flag leaf at the flowering stage (61 BBCH). At plant maturity, five plants of each pot were randomly harvested to measure grain yield per plant. Analysis of variance and mean comparisons were performed using SAS9.4 computer software packages. The main effects and interactions were tested using the least significant difference (LSD) test at 0.05 probability level.
Results and discussion
The results showed that both application of vermicompost and foliar application of 30% volume of methanol under salinity 100 mM increased the activity of peroxidase (73.4%), polyphenol oxidase (89.6%), soluble sugar (20.3%), protein (38%), proline (101.9%) and relative water content (20.6%) in compared to no application of vermicompost and methanol under the same of salinity level. Application of vermicompost decreased MDA and H2O2 content (9 and 20% respectively) in compared to no application of vermicompost. Foliar application of 30% volume of methanol decreased MDA and H2O2 content (40 and 55% respectively) in compared to no methanol application. Maximum of grain yield was obtained in both application of vermicompost and methanol at 30% volume under no salinity.
Conclusion
Based on the results of this study, it seems that the application of vermicompost and methanol can increase the grain yield of triticale under salinity stress due to improving activity of antioxidant enzymes and compatible osmolytes.
Fatemeh Hosseini; Sayyed Saeed Moosavi; Mohammad Reza Abdollahi; Ali Sepehri
Abstract
Introduction: Wheat is the most important crop that occupies the most area under rainfed cultivation. Drought stress is the most important factor in wheat yield reduction. The scope of this stress is expanding day by day in the world. Drought resistance is a quantitative trait with a complex ...
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Introduction: Wheat is the most important crop that occupies the most area under rainfed cultivation. Drought stress is the most important factor in wheat yield reduction. The scope of this stress is expanding day by day in the world. Drought resistance is a quantitative trait with a complex phenotype that is affected by plant growth stages. Breeding requirements for resistance to drought stress in wheat are two factors: high genetic diversity among cultivated and wild genotypes of wheat and selection based on traits related to this resistance. One of the important strategies to deal with moisture stress is using wild relatives of wheat, especially the genus Aegilops, as one of the important gene sources containing genes for resistance to environmental stresses. Based on this limitation, the use of wild wheat relatives is one of the important goals of wheat breeding programs. This research aimed to evaluate the relationship between grain yield and 32 different phenological and agro-physiological traits in ten ecotypes of Aegilops tauschii which was carried out under moisture-stress conditions and for two period. Materials and methods: This study was conducted for two consecutive periods in the research greenhouse of the Faculty of Agriculture of Bu-Ali Sina University in Hamedan. In this study, 33 phenological, morphophysiological, and root traits were evaluated in ten ecotypes of diploid wheat Aegilops tauschii (2n=2x=14, DD) under drought stress conditions. These ten different ecotypes of Aegilops tauschii were collected from different geographical regions of Iran.The mentioned ecotypes were evaluated in a randomized complete block design with three replications. At first, the seeds of the plant samples were grown in seedling trays containing equal proportions of perlite and cocopeat. Then, for the vernalization of the plants, after the initial germination of the seeds, in the two-leaf stage of the seedlings, the culture trays were moved to a cold room with a temperature of 4 degrees Celsius for about 35 days. After this stage, the vernalized seedlings were transferred to 10 kg pots, containing a combination of agricultural soil, sand, and rotted animal manure at a ratio of 50, 25, and 25%. After transplanting, the pots were irrigated at 100 percent of the soil's field or pot capacity for about two weeks. Then, in order to apply drought stress treatment, the humidity of the pots was kept at 45% of the field or pot capacity until the plants were harvested, by weighted moisture method. Results and discussion: Economic yield has a positive and significant correlation (p≤0.01) with the traits of grain water use efficiency, peduncle length, plant harvest index, main spike weight, grain weight in main spike, number of fertile spikes per plant, thousand-grain weight, plant height, excited leaf water retention, number of grains per plant, peduncle weight and leaf surface index. This was despite the fact that most of the phenological and root traits had a significant negative correlation with grain yield. According to the stepwise regression results, the traits of grain water use efficiency and the number of fertile spikes per plant with a positive coefficient and the traits of root diameter and days to heading, with a negative coefficient, as the most important traits affecting grain yield, were entered into the regression model respectively. The results of the path analysis indicated that the trait of grain water use efficiency had the most direct and positive effect on increasing grain yield. Also, the trait of water use efficiency, through the trait of day to heading, had the most negative indirect effect on grain yield. Conclusion: According to our findings, the selection based on higher values of grain water use efficiency and the number of fertile spikes per plant and lower values of phenological and root traits may lead to improvement of wheat grain yield under drought stress conditions.
Elaheh Seyfipour Naghneh; Najmeh Yarami; Abolfazl Azizian; Gholamhassan Ranjbar
Abstract
Introduction:
In the irrigated agriculture of Iran, the quantitative and qualitative limitations of water resources and consequently, drought and salinity stresses, always threaten crop production. This problem exists in most regions of the country. Sesame is one of the oilseed and industrial ...
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Introduction:
In the irrigated agriculture of Iran, the quantitative and qualitative limitations of water resources and consequently, drought and salinity stresses, always threaten crop production. This problem exists in most regions of the country. Sesame is one of the oilseed and industrial crops that is somewhat resistant to drought and salinity and its placement in the cultivation pattern can provide some part of the country's need for sesame production and oilseed crops. Sesame is known as the queen of oil seeds because of its high percentage and quality of oil and high properties for health. The aim of this study was to investigate the water productivity, leaf area index, and some physiological traits of sesame Oltan variety including canopy cover temperature, Chlorophyll index, and water potential under simultaneous drought and salinity stresses.
Materials and methods:
A factorial experiment in randomized complete block design was conducted in Research Farm of Ardakan University during the 2019 to 2020 growing season with three replications. Experimental factors were four salinity levels of irrigation water including 1.5, 4, 7, and 10 dS.m-1 and three drought levels with different irrigation intervals as 4, 8 and 12 days, respectively. During the growing season, leaf area index, canopy cover temperature, and chlorophyll index were measured for four times (35, 50, 65 and 85 days after sowing). Leaf water potential was also measured in the mid-growing season. Water productivity for grain production was also determined. Statistical analysis was done using SPSS version 22 software and averages were compared with Duncan's test at 5% probability level.
Results and discussion:
Results showed that the irrigation interval had a significant effect on the leaf area index, leaf water potential, grain yield, and water productivity. Irrigation water salinity had a significant effect on all of the studied traits, the interaction of the drought and salinity stresses was not only significant on SPAD index. Increasing the irrigation interval from 4 to 12 days and increasing water salinity from 1.5 to 10 dS m-1 decreased the maximum leaf area index of sesame by 49% and 58%, respectively. Also, an increase in salinity from 1.5 to 10 dS.m-1 resulted in 18% increase in leaf temperature, 40% decrease in SPAD index, and 17% decrease in leaf water potential. The increase in drought stress also had no significant effect on leaf temperature, while it caused 14% increase in SPAD index and 15% decrease in leaf water potential. Increasing the irrigation interval from 4 to 8 and 12-day caused a 67 and 68% significant decrease in grain yield, respectively. There was no significant difference in the grain yield of 8 and 12-day irrigation interval. Increasing the water salinity from 1.5 to 4, 7, and 10 dS.m-1 decreased the grain yield by 35, 80, and 96%, respectively. Increasing the irrigation interval from 4 to 8 and 12 days caused a 55 and 51% decrease in water productivity, respectively. This index decreased significantly (95%) by increasing water salinity from 1.5 to 10 dS.m-1.
Conclusion:
Water productivity and maximum leaf area index decreased significantly by increasing water salinity and irrigation interval. An increasing trend in leaf temperature was observed with increasing salinity, which is due to the decrease in plant transpiration under exposure to salinity stress. The SPAD index showed a decreasing trend with the increase in salinity, while the increase in drought stress (increasing the irrigation interval) caused an increase in this index. Sesame leaf water potential also decreased by increasing salinity and drought stresses. Generally, results showed that leaf area index and studied physiological traits of sesame were more affected by water salinity stress than drought stress. The results of interaction also showed that in all investigated traits, except for leaf water potential, no significant difference was observed between 8 and 12-day irrigation interval at all salinity levels. In 1.5 and 4 dS.m-1 salinity levels, the difference in grain yield and water productivity were significant in 4 and 8-day irrigation interval, while there was no significant difference in 7 and 10 dS.m-1 salinity levels. Although the highest grain yield and water productivity were observed in the 4-day irrigation interval and 1.5 dS m-1 salinity level treatment, based on the results of physiological traits, grain yield, and water productivity of sesame, especially under water shortage conditions, it is recommended to use 12-day irrigation interval instead of 8-day because there was no significant difference in the water productivity.
Fatemeh Mohamadi Azar; Omid Sofalian; Ali Asghari; Asghar Ebadi; Rahmatollah Karimizadeh
Abstract
Introduction
Wheat is one of the most important crops and an essential source of calories and protein in the world. Food security depends on agricultural production to supply the growing world population with certain nutrients. Plants are often exposed to stressful conditions. Stress can occur within ...
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Introduction
Wheat is one of the most important crops and an essential source of calories and protein in the world. Food security depends on agricultural production to supply the growing world population with certain nutrients. Plants are often exposed to stressful conditions. Stress can occur within minutes, days, or even months. Temperature is the most important environmental variable that affects the growth, development, and final productivity of agricultural grain products. Cold or freezing temperatures cause a lot of damage to agriculture, especially in cereal crops in subtropical and temperate regions. Most of the world's wheat fields are often under low-temperature stress. The ability of plants to tolerate cold without damaging their growth cycle is called cold tolerance. Crop plants, including wheat, tend to overcome cold stress through cold adaptation. In winter cereals, low-temperature stress in the vegetative stage causes chlorosis and wilting of leaves and eventually leads to necrosis and growth inhibition. Wheat needs an ideal temperature range for growth and ideal performance, and any deviation from it affects the natural growth process. In general, winter cereals like wheat have two varieties, sensitive to cold and resistant to cold. Numerous studies show that the intraspecies genetic diversity of wheat has not yet been fully exploited. The purpose of this study is to investigate the diversity of durum wheat lines under conditions of freezing stress, identify cold-resistant lines in durum wheat based on some morphophysiological traits, and determine the relationship between durum wheat traits and cold tolerance.
Materials and methods
Freezing and laboratory experiments were carried out in the greenhouse and plant breeding laboratory of Mohaghegh Ardabili University in 2019 on 45 durum wheat genotypes as a factorial experiment in the form of a randomized complete block design with three replications. In this experiment, four control temperature treatments (without freezing), -8, -10 and -12 degrees Celsius were investigated. LT50 of several applied temperatures (-8, -10, and -12), and by analyzing Probit was calculated for each genotype. The mean comparison was done with the LSD method at the five percent probability level. Lines grouping was done by Ward's clustering method using the square measure of Euclidean distance.
Results and discussion
The highest amount of LT50 trait was observed in genotype number 44, and the lowest amount was observed in genotype number 36. LT50, survival percentage, height, fresh weight of shoots, dry weight of shoots, saturated weight of shoots, number of leaves, relative water content, and electrolyte leakage were investigated. The correlation was calculated separately in stress levels. Lines with high height in terms of LT50 trait were also included in the group of resistant lines. Multivariate variance analysis based on unbalanced one-way variance analysis was used to determine the most favorable groups. The lines were placed in four groups in the control conditions, the stress of -8, and -12°C, and in five groups in the -10°C stresses. The traits of shoot weight, number of leaves, relative leaf water content and electrical conductivity had an important role in the average of the groups. Decomposition into factors was done in separate stress levels. Four factors were selected in control levels, and -8°C stress, and three factors were selected in the -10°C, and -12°C stress levels.
Conclusion
In general, lines 35, 40, and 44 were recognized as lines with higher averages in all clusters, and lines 4, 5, 6, and 20 were placed in groups with lower averages. The traits of shoot weight, number of leaves, relative leaf water content, and electrical conductivity had an important role in the average of the groups. According to the final results of the study, lines 17, 24, 27, 35, 38, and 40 were recognized as resistant lines. Lines 3, 12, 18, 20, and 44 were found to be sensitive.
Acknowledgments
We sincerely thank Gachsaran Agricultural Research Institute and Maragheh dryland Agricultural Research Institute for providing the studied lines seeds.
Elham Afsharnia; Alireza KhavaninZadeh; Mehdi Karimi
Abstract
IntroductionWater and soil salinity is one of the most important environmental factors limiting the growth and performance of plants around the world, especially in arid and semi-arid regions. The increase in population on the one hand and the decrease of fresh water and soil resources on the other hand ...
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IntroductionWater and soil salinity is one of the most important environmental factors limiting the growth and performance of plants around the world, especially in arid and semi-arid regions. The increase in population on the one hand and the decrease of fresh water and soil resources on the other hand has doubled the necessity of studying in relation to the identification of salinity resistant plant species and strategies for the efficiency of saline soil and water resources. Therefore, this study was conducted with the aim of finding and determining the salinity resistance of artichoke plant species and the growth rate of the species under different conditions of irrigation water salinity and evaluating the performance of vegetative and physiological growth parameters in field conditions in order to use this plant in areas with limited water salinity.Materials and methodsIn order to evaluate the salinity resistance of the artichoke medicinal plant species and to determine the salinity resistance of this species, an experiment was conducted with six salinity levels including (control), 9, 12, and 15 dS m-1 in a completely randomized design and in three replications in potted conditions. Four weeks after applying salinity stress, traits including photosynthetic pigments, dried leaves, leaf water content, leaf dry weight, ash content, SLA were measured. Finally, significant difference at 5 percent level statistically were calculated among treatments using analysis of variance and mean differences was calculated using Multiple Duncan test.Results and discussionResults showed that salinity treatment has a significant effect on the characteristics of total chlorophyll, percentage of dryness and leaf fall, percentage of leaf ash, leaf specific weight and moisture content of leaves at the level of five percent, and the Artichoke plant can tolerate salinity up to 9 dS m-1 but it is sensitive at higher levels of salinity. In other words, the salinity of 12 dS m-1 has reduced the germination of Artichoke species by more than 50% and caused a significant increase in ash percentage, as well as drying and leaf fall percentage by 50%, and significant decreasing in leaf water content, dry root weight while it significantly increased electrolyte leakage which can indicate a significant decrease in vegetative growth and performance of this species at this level of salinity. According to the results, per unit increase in salinity, the weight loss of Artichoke leaves was recorded as 11%. In general, Artichoke plant species, in terms of resistance to salinity, it has a relatively good tolerance, and it seems this plant species can be used for cultivation and production by using saline water sources up to 9 dS m-1 in condition of the study area.ConclusionsThe results showed that there is no significant difference in yield and growth of Artichoke by increasing water salinity up to 9 dS m-1 in the study area. In farm and pod condition, experimental treatments showed a significant effect on increasing leaf fall, ash and water content, leaf dry weight by increasing water salinity to 12 dS m-1 . In general, Artichoke as an important medicinal plant, is a moderate up to tolerant species in salinity and it seems it is a proper species for cultivation and plant production in area with saline water up to 9 dS m-1 in condition of study area. According to the results, it seems water salinity up to 12 dS m-1 significantly decreases vegetative growth of the species up to 50% but it is a need more studies for impact of salinity on flowering and seeding stages as well. we recommend more studies in different climate conditions to reveal impact of these conditions on salinity resistance of the plant species.AcknowledgementsWe thank the National Salinity Research Center for their cooperation in the implementation and providing water and land for experiments in this study.
Toktam Ahmadi; Seyed Hossein Nemati; Jafar Nabati
Abstract
Introduction
Cold and freezing temperatures can cause serious damage to the potato plant (Solanum tubersum L.) and decrease yield. In intense cases, the cold stress can even destroy the entire production. Most potato cultivars are sensitive to cold, and temperature plays a crucial role in their geographic ...
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Introduction
Cold and freezing temperatures can cause serious damage to the potato plant (Solanum tubersum L.) and decrease yield. In intense cases, the cold stress can even destroy the entire production. Most potato cultivars are sensitive to cold, and temperature plays a crucial role in their geographic dispersal. Physiological responses of plants to cold stress include increased calcium transfer, changes in membrane lipid composition, enhanced antioxidant capacity, and accumulation of osmotic protectors. Compatibility, which involves the aggregation of cold-protecting polypeptides and osmolytes, is the primary method that plants use to cope with cold stress. Cold-compatible plants often store higher levels of soluble carbohydrates in their underground tissues. This study was conducted to investigate the mechanisms of cold tolerance in four potato cultivars: Agria, Fontane, Arinda, and Santé, highlighting the importance of cold stress to potato plants.
Materials and methods
The study was conducted using a completely randomized design with four replications. The factors considered were temperature (4, 2, 0, -2, -4°C) and potato cultivars (Agria, Fontane, Arinda, and Sante). To evaluate the response to cold, six-week-old seedlings were transferred to a thermogradient freezer with darkness and a temperature of five degrees Celsius. The temperature gradually decreased at a rate of two degrees Celsius per hour, and the seedlings were exposed to the desired temperatures (-4, -2, 0, +2, +4 °C) for one hour. Two weeks after exposure to cold stress, the percentage of survival, plant height, and the highest shoot dry weight of the cultivars were recorded. The content of malondialdehyde (MDA), soluble carbohydrates, total phenols, proline, catalase enzyme activity, peroxidase, and superoxide dismutase were evaluated. The statistical analysis was performed using Minitab v.17.3.1 software, and mean comparison was conducted using Duncan's multi-range test at a five percent probability level with standard error.
Results and discussion
The results revealed that the survival rate in cultivar Santé significantly decreased with decreasing temperature. Cultivar Fontane exhibited a higher survival rate than other cultivars at a temperature of -4°C. The phenol content in cultivar Santé at -2°C was 81% higher than in cultivar Fontane. In cultivar Sante, the proline content increased fourfold as the temperature decreased from 4 to 0°C. In cultivar Fontane, the proline content increased with a temperature decrease from 4 to -2°C and then decreased with further temperature reduction. The soluble carbohydrate content increased with a temperature decrease in cultivars Santé, Arinda, and Agria, while it decreased in cultivar Fontane. Cultivar Santé exhibited the highest increase in MDA (malondialdehyde) content, whereas cultivar Fontane showed the lowest increment when the temperature decreased from 4 to -4°C. Regarding enzyme activities, the CAT (catalase) enzyme activity increased 9.2-fold in cultivar Santé at a temperature of 0°C. In cultivar Fontane, the highest CAT enzyme activity was observed at 2°C. The POD (peroxidase) enzyme activity showed the highest increase in cultivar Santé with a temperature decrease to -2°C. In cultivar Fontane, the SOD (superoxide dismutase) enzyme activity decreased with a temperature decrease to 2°C and then increased by 80% with further temperature reduction to 0°C. After exposure to cold stress, plant height decreased in cultivars Santé and Agria compared to the control, while it increased in cultivar Fontane with a temperature decrease. The highest shoot dry weight was observed in cultivar Fontane at a temperature of -4°C, whereas the lowest shoot dry weight was observed in cultivar Sante.
Conclusion
Generally, this study showed that cultivar Santé is more sensitive to cold than cultivars Agria, Fontane, and Arinda. On the other hand, cultivars Fontane and Agria were found to be more tolerant. The studied metabolites and antioxidant compounds of cultivar Fontane were more significant under cold stress conditions, indicating more efficient defensive mechanisms compared to other cultivars. This ultimately resulted in better cold tolerance for cultivar Fontane.
Hamid Najafinezhad; Mohammad Ali Javaheri; Nader Koohi
Abstract
IntroductionLack of fodder for feeding livestock is one of the main problems of dry areas, especially in the southern regions of Iran. In this situation, the climate changes and the decrease of rainfall in the southeast of the country in recent years, have doubled the important of compatible plants with ...
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IntroductionLack of fodder for feeding livestock is one of the main problems of dry areas, especially in the southern regions of Iran. In this situation, the climate changes and the decrease of rainfall in the southeast of the country in recent years, have doubled the important of compatible plants with the potential to produce fodder in water shortage conditions. Fodder cactus is a drought-resistant plant that adapts to dry and low-water conditions as a source for fodder production in dry areas. This research was conducted to explore the effect of drought stress on yield, water productivity, and some agronomic characteristics of cactus as a new crop in the climatic conditions of Shahmaran region of Kerman, Iran. Materials and methodsThe experiment was carried out in the form of randomized complete block design with four replications. Three treatments of normal irrigation, moderate and severe drought stress were considered based on 160, 210 and 260 mm cumulative pan evaporation. The cladodes (Opuntia ficus-indica) used for planting, originating from Tunisia. In each plot, 32 cladodes were planted at a distance of 2 meters between rows and 1.5 meter between cladodes on a row. At the time of irrigation of each treatment, volumetric soil moisture was measured at the active depth of root development using a calibrated Time-Domain Reflectometry device (Trime-FM, IMKO, Ettlingen, Germany). To calculate the fodder yield of cactus, the cladodes produced on plants in each plot were harvested and weighed. For measuring the length, width, and thickness of the cladode in each plot, 10 cladodes were randomly selected, and the average of each trait was finally determined. Results and discussionThe number of pads produced under the influence of drought stress was significant. The highest number of pads per plant was observed in the normal irrigation treatment (27.7 pads per plant) and the lowest in the severe drought stress treatment (15 pads per plant). The maximum thickness of the pad under normal irrigation condition was 2.4 cm and the minimum thickness was observed under severe drought stress condition. The main reason in reducing the thickness of the pad in water stress condition was the decreasing of the pad moisture content.The effect of drought stress on the length and width of the pad, was significant. Minimum length and width of the pad was observed with 29.5 and 18 cm in severe drought stress treatment and the maximum with 37.7 and 24.7 cm in normal irrigation treatment.The percentage of pad dry matter at the time of sampling was significantly affected by water stress treatments. The dry matter percentage was the lowest in the normal irrigation treatment with 8% and the highest in the severe water stress treatment with 12.7%.The weight of the each pad and the yield of wet and dry fodder per hectare were significant under the influence of different water stress treatments. The wet weight of the pad per plant was the highest in the normal irrigation treatment with 1245 g and the lowest in the severe water stress treatment with 870 g. Normal irrigation treatment produced the highest yield by producing 112 and 8.97 t.ha-1 of fresh and dry fodder, respectively. The lowest wet and dry yield belonged to severe water stress treatment with production of 46.77 and 6.05 t.ha-1.The highest water productivity for wet and dry cactus fodder was 41.02 and 3.29 kg m-3 respectively, which belonged to the normal irrigation regime. There was no significant difference between moderate and severe water stress treatments for dry fodder in terms of water productivity. ConclusionOverall, the research results showed that drought stress has a significant effect on fodder yield, water productivity, cladode thickness, cladode length and width, cladode weight, and crude protein of cactus fodder. Despite the physiology of the cactus and its resistance to water stress, with the increase of drought stress, the wet and dry yield, water productivity, and fodder protein content showed a significant decline. According to the results, reduction of 58.2% in wet fodder yield and of 32.5% in dry fodder yield were seen in severe drought stress treatment compared to normal irrigation. The average water consumption was 2507.6 m3.ha-1. According to the results, in order to benefit from the potential of the cactus to produce fodder, it is necessary to avoid long-term and severe drought stress. The vegetative growth period of cactus was mainly found in spring and early summer. With the cooling of the air from late fall to early March, the plant is going to be entered the stage of growth stagnation. Due to the evergreen nature of the plant, the fodder of this plant can be used for feeding livestock in the fall and winter seasons, when there is a lack of fresh fodder. This research determined that there is a possibility of growing and developing cactus plant as a new plant in Shahmaran region with a subtropical climate. Also, through cultivation of this plant with low water consumption, part of the fodder shortage for livestock in Kerman province can be resolved.
Ahmad Shahizadeh; Rasool Asghari Zakaria; Marefat Ghasemi K.; Parisa Sheikhzadeh Mosaddeq
Abstract
Introduction
Drought stress is the most critical cause of wheat yield reduction in semi-arid regions. Drought affects wheat yield somewhat during the growing season, but yield reduction predominantly occurs during the reproductive and grain-filling stages. This research aimed at the identification of ...
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Introduction
Drought stress is the most critical cause of wheat yield reduction in semi-arid regions. Drought affects wheat yield somewhat during the growing season, but yield reduction predominantly occurs during the reproductive and grain-filling stages. This research aimed at the identification of end-season drought stress-tolerant wheat genotypes based on tolerance and sensitivity indices using the ideotype genotype selection index (IGSI) and the multi-trait genotype–ideotype distance index (MGIDI) multi-trait selection indices.
Materials and methods
In this study, 18 bread wheat genotypes and two control cultivars were evaluated based on a randomized complete block design with three replications under two conditions: full irrigation and end-season drought stress. The experiment was conducted at the Ardabil Agricultural Research Station during the 2021-2022 season. The genotypes were sown in plots of 2.5 m × 3 m with a row spacing of 20 cm. The full-irrigation treatment received 100% of the crop's water requirement, while in the drought stress treatment, the irrigation stopped after heading. Standard agronomic practices were followed throughout the growing season and data on traits such as yield were recorded. Tolerance and stress indices, including tolerance index (TOL), mean productivity (MP), stress tolerance index (STI), modified stress tolerance index (MSTI), geometric mean productivity (GMP), harmonic mean (HM), stress susceptibility index (SSI), yield index (YI), yield stability index (YSI), and yield reduction percentage (YRP) were calculated. Statistical analysis was performed using ANOVA, and the means were compared using the least significant difference (LSD) test at the 5% probability level. Additionally, IGSI and MGIDI selection indices were also determined to evaluate the drought tolerance of the genotypes.
Results and discussion
The experiment results indicated that based on lower YRP, TOL, and SSI indices, genotypes 11, 5, 9, and 10 were selected as tolerant genotypes. Nevertheless, genotypes 12, 2, 1, and 6 were superior based on higher STI and Harm indices. Also, genotypes 12, 1, 11, and 3 were best in the k2STI and YI indices. Additionally, genotypes 14, 4, 2, and 6 were tolerant based on the k1STI index, genotypes 11, 9, 5, and 10 in the YSI index, genotypes 2, 12, 14, and 4 in the MP index, and genotypes 12, 2, 4, and 1 in the GMP index. Using the multivariate selection indices of the IGSI and MGIDI, genotypes 11, 5, 1, and 12, with the highest IGSI value and the lowest MGIDI value, are among the genotypes with high end-season drought stress tolerance. This was confirmed through heat map cluster analysis and bi-plot diagram in principle components analysis. Also, genotypes 20, 16, and 19, having the lowest value of IGSI and the highest MGIDI, showed higher sensitivity to drought stress. The comparison of the means of the selected genotypes with the total means showed that these genotypes under the end-of-the-season drought stress conditions performed better in stress conditions (with higher Ys) and had less yield reduction compared to the average of other genotypes.
Conclusion
The ideotype genotype selection index (IGSI) and the multi-trait genotype–ideotype distance index (MGIDI) for different genotypes based on the quantitative indices of tolerance and stress show that genotype 11, having a high value of IGSI and the lowest value of MGIDI is the most tolerant to end-season drought stress. The genotypes 5, 1, and 12 were ranked next. Based on these results, it is clear that different genotypes exhibit varying levels of drought tolerance based on the indices evaluated. Overall, the results of this experiment provide valuable insights into the potential for improving drought tolerance in wheat through the selection of tolerant genotypes using IGSI and MGIDI indices. The selected genotypes can be further evaluated for their agronomic and physiological traits to confirm their suitability for cultivation in drought-prone areas.
Leila Sadooghi; Aliakbar Noroozi; Ali Mohammadi Torkashvand; Ebrahim Pazira
Abstract
Introduction
Cooling stress has led to irreparable damage to the paddy fields of Gilan province. Climate research has shown the prevalence of increasing climate-related hazards including frost, drought, hail, and flood. Environmental stresses, including frost, affect different rice growth stages and ...
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Introduction
Cooling stress has led to irreparable damage to the paddy fields of Gilan province. Climate research has shown the prevalence of increasing climate-related hazards including frost, drought, hail, and flood. Environmental stresses, including frost, affect different rice growth stages and affect the morphological and physiological characteristics of rice. Cooling stress is a major risk to be managed and quantitative determination of cooling stress hazard is very serious in realizing the hazard and planning to reduce it. In developing countries such as Iran, meteorological stations are usually scattered. For this reason, they use sensors such as MODIS, that are free and available to help compensate for these deficiencies. Nowadays, remote sensing technology and satellite data provide an opportunity to achieve high-resolution data. Therefore, with the development of GIS and remote sensing, real-time cooling stress monitoring can be achieved in large areas. Also, we used interpolation models so scattered observations can be converted into continuous prediction maps of the entire study area. The objective of this research is to investigate the cooling stress hazard in different rice growth stages, using remote sensing technology and MODIS satellite images in Gilan province.
Materials and methods
In this research, the MOD11A1 product provides daily land surface temperature (LST) data used from the MODIS sensor, and the coordinates of meteorological stations in Gilan province and the required data from these stations during the statistical period from 2000 to 2017 were obtained from the Meteorological Department. The rice growth stage was determined based on the information and statistics of the province and using MODIS sensor images and according to the critical temperature limit below which the plant experiences cold stress.
Results and discussion
Cooling stress hazard zoning maps in ArcGIS software, according to the number of days when the cooling stress hazard in each of the plant growth stages (the germination, the seedling, the vegetative, and the reproductive stages) occurred in the region prepared. According to the root mean square error (RMSE) and coefficient of determination (R2) obtained, among the different interpolation methods, In different rice growth stages, the IDW method was chosen to prepare the zoning map.Then, the hazard zoning map was prepared according to the cooling stress hazard classification for the rice crop in different plant growth stages between 2000 and 2017 using the IDW method. Five different classes of cooling stress hazard rice were considered as very low, low, medium, high, and very high.
Conclusion
Based on the cooling stress hazard zoning maps during the 17 years investigated in the studied area, in the germination, seedling, vegetative, and reproductive stages, it showed that the highest cooling stress hazard is related to the altitudes of 1000 to 2000 meters in the mountainous areas, and during the growth stage germination and reproductive, the amount of this hazard is very high and we should choose the appropriate date for the germination period and every as we get to the sea, the level of hazard in all growth stages, even in the growth stages of germination and reproductive, is low and very low.
Akram Abasmanesh; Arash Fazeli; Reza Haghi Darehdeh
Abstract
IntroductionCereals are among the most vital agricultural products on a global scale, with an estimated annual production of around 904 million tons. Barley (Hordeum vulgare), a species within the Gramineae family, ranks as the fourth most important grain crop worldwide based on production. It is also ...
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IntroductionCereals are among the most vital agricultural products on a global scale, with an estimated annual production of around 904 million tons. Barley (Hordeum vulgare), a species within the Gramineae family, ranks as the fourth most important grain crop worldwide based on production. It is also the second most extensively cultivated cereal, covering 18% of the total cultivation area. This plant, which is currently at risk, demonstrates a considerable tolerance to non-living stresses. Abiotic stresses influence living organisms in diverse manners. In recent years, dust has emerged as a significant environmental challenge in western and southern Iran, leading to a reduction in soil moisture retention and negatively affecting plant health. Plants, due to their immobility, are particularly vulnerable to the adverse effects of air pollution compared to other organisms. Additionally, dust diminishes soil fertility, contributing to lower agricultural productivity and economic losses. The presence of dust on leaves further complicates these issues by obstructing light penetration, disrupting photosynthesis, reducing biomass production, and ultimately decreasing crop yields. This research seeks to analyze the impact of dust on the physiological characteristics of different barley genotypes.Materials and methodsThe research was conducted during the agricultural year 2022-2023 at the Faculty of Agriculture's research greenhouse at Ilam University. A factorial design was employed within a randomized complete block structure, incorporating three replications. The experimental factors included micro-dust treatments at two levels (with and without dust) and a selection of ten barley genotypes sourced from the IPK Institute's seed bank in Germany. To simulate dust stress, soil was collected from the Mehran region, sieved through 53-micron screens, and analyzed for physicochemical properties (refer to Table 2). A plastic chamber measuring 150 x 2.20 x 3.40 meters (length x width x height) was constructed to mimic conditions of a dust storm. Dust was applied during the seedling phase, and physiological traits such as leaf chlorophyll content, leaf soluble protein concentration, leaf proline content, and leaf soluble carbohydrates were evaluated ten days after the dust application. Following the assessment of these traits, variance analysis and mean comparisons were conducted using SAS 9.4 software, while graphs were generated using the GraphPad program. Mean comparisons were performed using the LSD (least significant difference) test at a 5% probability level, and correlation comparisons along with principal component analysis were executed using JMP software.Results and discussionThe results of this research highlighted the importance of the cultivar×dust interaction in influencing the levels of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, ion leakage, relative water content (RWC), proline, catalase, and sugars, all at a significance level of 1%. In contrast, neither dust nor dust treatment showed a significant effect on protein content. Exposure to dust resulted in decreased levels of chlorophyll, ion leakage, relative water content, and protein, while it caused increases in proline, catalase, and soluble sugars. Correlation analysis revealed a positive relationship among photosynthetic pigments, whereas their association with relative water content was negative. Furthermore, a strong positive correlation (r = 1) was identified between protein and carbohydrates. Factor analysis conducted on the examined traits identified three factors with eigenvalues exceeding one, which collectively accounted for 99.72% of the total data variation. Notably, relative water content exhibited a significant positive correlation with protein (r=0.758) at the five percent significance level.ConclusionThe findings indicate that dust stress negatively impacted photosynthesis, ion leakage, relative water content, and protein levels, while simultaneously elevating carotenoids, proline, catalase, and soluble carbohydrates. The effects of dust stress varied across different cultivars, with certain traits in specific cultivars showing increased vulnerability. Remarkably, the HOR6964 genotype demonstrated a higher level of resilience in comparison to other genotypes.
Parvaneh Gholizadeh Sarcheshmeh; Jalal Saba; Hassan Amirioghan; Farid Shekari; Amir Gholizadeh
Abstract
Introduction
Today, lack of water is one of the most important factors limiting crop growth in arid and semi-arid regions, and the reduction in growth caused by drought stress is far more than other environmental stresses. In order to investigate the relationships between yield and agronomic and phenological ...
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Introduction
Today, lack of water is one of the most important factors limiting crop growth in arid and semi-arid regions, and the reduction in growth caused by drought stress is far more than other environmental stresses. In order to investigate the relationships between yield and agronomic and phenological traits and to determine the relationships between these traits in spring rapeseed genotypes, seven rapeseed lines were crossed with five testers under two moisture conditions in the 2019-2020.
Materials and methods
The first generations hybrids along with 12 parents were evaluated under normal irrigation conditions and drought stress at the end of the season. Under normal irrigation conditions, irrigation was carried out in the stages of cultivation, rosette, stem growth, flowering, stem formation and grain development. Manual weeding was done to control weeds. In order to apply drought stress at the end of season, irrigation is stopped after flowering. The traits evaluated in this research included days to flowering, days to end of flowering, length of flowering period, days to physiological maturity, plant height, number of pods per plant, length of pods, number of grain per pods, height of the first pods from the ground, 1000 grain weight, grain yield per hectare, oil percentage, number of pods in the sub-branches, number of pods in the main stem, number of sub-branches, diameter of pods, length of the main stem, diameter of the stem at a height of 20 cm.
Results and discussion
The correlation results of traits in normal irrigation conditions showed that grain yield had a positive and significant correlation with the traits of number of pods per plant, number of pods in sub-branches, stem diameter at a height of 20 cm, number of seeds in pod and number of sub-branches. Under drought stress at the end of the season, number of pods per plant, number of seeds per pod and diameter of pod had a positive and significant correlation with grain yield and day to flowering had a negative and significant correlation with grain yield. Based on the results of the stepwise regression analysis in both conditions, the number of pods per plant under normal irrigation conditions and drought stress justified most of the changes in the regression model. Based on the results of path analysis in both experiment conditions, number of pods per plant, thousand grain weight, number of grains per pod and the height of the first pod from the ground have direct positive effects and days to physiological maturity had direct negative effect on grain yield. Also, the length of the main stem under normal irrigation conditions and the number of pods in the sub-branches under drought stress conditions at the end of the season had direct negative effects on grain yield. However, all these negative direct effects were neutralized by positive indirect effects through other traits and caused the correlation coefficients of these traits with grain yield to become insignificant. In principle component analysis, in normal irrigation conditions, the total of 6 independent factors justifed about 75.9% of the changes, the first component including the number of pods in sub-branches, the number of pods per plant and the diameter of the stem at a height of 20 cm. In the conditions of drought stress at the end of the season, a total of 7 independent factors justified about 75.2% of the changes, the first factor consisting of the number of pods in the sub-stem, the number of pods per plant, the number of sub-branches, the diameter of the stem in the height of 20 cm.
Conclusion
In general, in both conditions of normal irrigation and drought stress at the end of the season conditions, the number of pods per plant and the number of grains per pod had a high share of total changes and were the most effective traits on grain yield. Therefore, since these traits are more heritable than grain yield, selection to increase them can be recommended for indirect improvement of grain yield in breeding programs.
Majid Rajaie; Sirus Tahmasebi; Manouchehr Dastfal
Abstract
Introduction
Environmental stresses are the most important factors reducing the yield of agricultural crops in the world. Salinity stress affects 20% of the worl’s arable lands, which increases day by day due to climate change and human activities. Wheat has great genetic diversity for salt tolerance. ...
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Introduction
Environmental stresses are the most important factors reducing the yield of agricultural crops in the world. Salinity stress affects 20% of the worl’s arable lands, which increases day by day due to climate change and human activities. Wheat has great genetic diversity for salt tolerance. Improvement and development of salinity tolerant cultivars is a suitable solution to reduce the negative effects of salinity. This research was conducted to investigate and determine the most tolerant varieties and promising lines of wheat to different levels of irrigation water salinity.
Materials and methods
In order to evaluate the response of bread wheat cultivars and lines to different levels of salt water and to determine the salinity tolerance indices, a factorial greenhouse experiment was conducted in a completely randomized design with three replications in the Agricultural and Natural Resources Research and Education Center of Fars province in 1399-1400 years. The light condition of the greenhouse was natural and its temperature was in balance with the outside environment. The experimental factors included wheat genotypes and different degrees of salt water. Wheat genotypes including commercial cultivars and some promising lines including Sistan, Narin, Brat, Sarang, Shush, Ayeneh, Sahar, Mehrgan, Ms-90-15, Ms-92-8, Ms-93-5, Ms-93-6, Ms-93-14, Ms-93-16 and S-94-12 were investigated. The salinity treatments tested with salinities lower and higher than the tolerance limit of wheat in values of 1, 10 and 16 dS m-1. Grain yield (g pot-1) and yield components including 1000 grain weight, number of fertile spikes per pot, number of grains per spike and biological yield (g pot-1) were recorded. Also, using the grain yield data, stress tolerance indices were calculated for medium and severe salt stress. Also, selection index of ideal genotype (SIIG) technique was used in order to investigate genetic diversity and integrate different indices into one selection index. Data variance analysis for different traits was done using SAS statistical software version 9.1. and mean comparison was done using Duncan's multi-range test at 5% probability level.
Results and discussion
Medium salt stress caused a decrease of 30, 26, 24, 26 and 20% in grain yield, biological yield, number of spikes per pot, number of grains per spike and 1000 seed weight of genotypes compared to control respectively. These reductions for severe salt stress were 53, 50, 42, 43 and 33% respectively. Mean comparison for the average of all cultivars in salinity levels showed that Sarang, Mehrgan, Brat, Sistan, Narin and S-94-12, without significant differences, had the highest biological yield, respectively. Also, for other yield components, the same genotypes along with Shush had the highest amount without significant difference. For grain yield, Sarang, Mehrgan, S-94-12, Barat, Shush, Narin and Sistan genotypes had the highest values. In the medium saline environment, S-94-12 and MS-92-8 lines had the lowest and highest percentage of grain yield reduction, respectively, compared to the non-saline environment. For severe salinity environment, the same reductions were observed in Mehrgan variety and MS-93-6 line. Based on the obtained results, the use of saline water of 10 ds/m decreased the grain yield of Sistan, Narin, Ms-90-15, Ms-92-8, Ms-93-5, Ms-93-6, and Ms-93-14, Ms-93-16, Brat, Sarang, Shush, Ayeneh, Sahar, Mehrgan and S-94-12 by 32.6, 36.2, 24, 40.5, 29.8, 32.5, 32.3, 26, 27.3, 30.5, 36.6, 21.7, 26.8, 30.2 and 15.6% respectively compared to non-saline irrigation water. These reduction values for 16 dS m-1 were 47.3, 56.3, 47.8, 50.6, 57, 65.4, 56.2, 50.2, 51.2, 50.5, 50.6, 46.6, 50.8, 47.3, 43.4 and 48.8%. Sodium content of leaves increased significantly with increase in salinity stress. The lowest sodium content with the amount of 0.257 and 0.259 percent was observed in Mehrgan and Sarang. Leaf potassium content in Sistan, Mehrgan, Brat, Sarang and S-94-12 showed a significant increase compared to other genotypes. Mehrgan and Sarang cultivars had the lowest ion leakage with the amount of 33.04 and 34.44%, respectively. The highest ion leakage was observed MS-93-6, MS-93-14, MS-93-5 and MS-93-16 lines. In order to increase the selection efficiency of superior genotypes, in addition to stress tolerance indices, the selection index of ideal genotype (SIIG) was used to integrate all stress tolerance indices into a single index. Investigation of the relationships between genotypes using the biplot analysis method and salinity tolerance indices showed that MP, GMP, HM and STI indices had a positive and significant correlation with yield in all levels of salinity.
Conclusion
The results of the biplot analysis and the relatively high correlation between yield under normal and stress conditions showed that cultivars that have high yields under normal conditions will also show high yield under salinity stress conditions. Also, based on stress tolerance indices as well as SIIG selection index, Mehrgan, Sarang and Brat cultivars as well as promising line S-94-12 in greenhouse test conditions (under natural ambient light and temperature conditions), had better yield under saline conditions. The reason for this could be the greater adaptability of these cultivars to the climatic conditions of the introduced region compared to other investigated cultivars, including the cultivars introduced for saline conditions of other regions.
Esmaeil Fayaz; Ali Sorooshzadeh; Ali Heidarzadeh
Abstract
IntroductionRapeseed is one of the most important oilseed plants is cultivated in most regions of the world. Drought stress hurts the growth, development, and productivity of plants. and Canola, like many crops, is affected by this stress. Amino acids are one of the most important primary metabolites ...
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IntroductionRapeseed is one of the most important oilseed plants is cultivated in most regions of the world. Drought stress hurts the growth, development, and productivity of plants. and Canola, like many crops, is affected by this stress. Amino acids are one of the most important primary metabolites in plant cells that perform structural, metabolic and transport functions in plants, and many physicochemical characteristics of plant cells, tissues and organs are affected by the presence of amino acids. Considering the importance of oilseed rape cultivation in Iran in oil production and the problems of water scarcity at the end of the growing season of this plant, this research was conducted to study the oil rapeseed biochemical traits and oil yield change under amino acid foliar spraying and drought stress at the end of the season.Materials and methodsThis experiment was carried out as a factorial design based on randomized complete blocks in the research farm of the Faculty of Agriculture of Tarbiat Modares University, during the 1401-02 growing season. The experimental treatments include irrigation regimes at three levels (full irrigation, withholding irrigation from 50% flowering stage, withholding irrigation from pod forming) and foliar spraying at five levels (no foliar spraying, zero foliar spraying (distilled water), one, two and three grams of amino acids per liter). leaf area index (by DELTA-T DEVICES made in England) and greenness index (by SPAD) were measured one week after the last foliar spraying. Total chlorophyll, anthocyanin, flavonoid, proline, and phenol were measured based on fresh plant samples in laboratory according to the protocol. At maturity, biological yield, oil content and oil yield were measured. Statistical calculations of analysis of variance and mean comparisons were performed using SAS 9.4 software.Results and discussionThe results showed that the interaction of drought stress and foliar spraying significantly affected the percentage and yield of oil, total chlorophyll, anthocyanin, flavonoid, proline, total phenol, leaf area index, SPAD and biological performance. Drought stress caused a significant decrease in traits such as leaf area index, yield and oil percentage, biological yield and total chlorophyll content. However, foliar spraying of amino acids at different levels reduced the negative effect of drought stress on the investigated traits. The results showed that the interaction of drought stress and foliar spraying significantly affected leaf area index, SPAD, biological yield, oil percentage and yield, total chlorophyll, anthocyanin, flavonoid, proline and total phenol. The highest leaf area index (3.52), biological yield (25955 kg/ha) and oil content (43.3%) were achieved by full irrigation conditions and foliar spraying of two grams of amino acids per liter. Also, the highest amount of anthocyanin (0.093 µmol g-1FW), flavonoid (1.64 µmol g-1FW) and proline (238.2 µmol g-1FW) were obtained by foliar spraying two grams of amino acids per liter under withholding irrigation from the flowering stage. Also, applying two grams of amino acid per liter produced the highest yield of oil (1924.6 kg/ha).ConclusionAccording to the results of this research, the positive effect of foliar spraying of amino acids on biochemical traits and oil yield was obtained by foliar spraying of two grams of amino acids per liter in all three irrigation regimes (full irrigation, withholding irrigation from 50% flowering stage, withholding irrigation from pod forming). Therefore, foliar spraying of two grams of amino acid per liter is recommended to increase oil yield in oilseed rap cultivation.
Leila Akbari; Zeinab Chaghakaboodi
Abstract
IntroductionOne of the most significant global challenges is drought stress, which leads to a reduction in agricultural and horticultural crop yields and an increase in secondary metabolites. Zinc, as a mitigating factor against drought stress, plays a crucial role in this context. Chlorophyll fluorescence ...
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IntroductionOne of the most significant global challenges is drought stress, which leads to a reduction in agricultural and horticultural crop yields and an increase in secondary metabolites. Zinc, as a mitigating factor against drought stress, plays a crucial role in this context. Chlorophyll fluorescence parameters are essential for assessing the photosynthetic capacity throughout the plant's lifecycle. This study aimed to compare resistance to varying moisture levels, evaluate physiological indicators, and assess the functionality of photosystem II using chlorophyll fluorescence parameters and biochemical characteristics. Plant adaptation to drought is examined through various physiological, morphological, biochemical, and molecular responses and adjustments. Soluble sugars help prevent protein and cell membrane dehydration by maintaining osmotic pressure in plant leaves under drought stress conditions.Materials and methodsIn a factorial experiment with a completely randomized design, the first factor comprised three levels of drought stress (75%, 50%, and 25% of field capacity), while the second factor included three concentrations of zinc nitrate (0, 5, and 10 mg.l-1) applied to the Balangue (Lallemantia iberica) plant. The uppermost leaves of the plant were selected to determine the desired indices and were covered with special clamps for fifteen minutes. Subsequently, light was shone on the leaf for two seconds using a device, and the desired indicators were recorded. The aerial parts of the plants were harvested, dried, powdered, and soaked in ethanol and methanol at room temperature for 48 hours to assess biochemical characteristics. The concentration of methanolic and ethanolic extracts was performed using a rotary evaporator, and the samples were stored in a refrigerator.Results and discussionIn the results comparing the mean with increasing levels of drought stress and application of foliar spraying with nitrate, there was no decrease in Pi and Fv/Fm at different stress levels. The greatest effect of foliar spraying was related to the amount of ten milligrams per liter of zinc nitrate in the investigated levels. Also, at different levels of drought stress, foliar spraying using zinc nitrate caused a significant change in the amount of phenol (13.50 mg.l-1), soluble sugar (94.15 mg.l-1), and flavonoid (8.49 micrograms). per liter and anthocyanin content (0.138 μg.l-1).ConclusionThe results have shown that the application of moisture stress at the investigated levels significantly increased the content of biochemical traits (soluble sugar, total phenol, flavonoid content, and anthocyanin content) and chlorophyll fluorescence indices. Increasing the level of carbohydrates, especially sugars, plays an important role in protecting and regulating osmosis. Additionally, the accumulation of soluble sugar molecules stabilizes the structure of macromolecules and ultimately prevents the deformation and destruction of biological molecules. Therefore, the use of foliar spraying at two levels of five and ten milligrams of zinc nitrate during the stress period has shown a decrease in the level of these compounds. The highest difference was related to 50% moisture stress and the use of 10 mg.l-1 of zinc nitrate. The use of zinc oxide and green zinc nanoparticles in the soil and foliar application by spray significantly increases the absorption of nitrogen, phosphorus, potassium, and zinc and reduces the adverse effects of drought stress. Therefore, under the influence of different moisture regimes at various growth stages of the plant, it is possible to improve the growth of the plant and enhance the biochemical characteristics of the balangue plant under drought stress conditions by using foliar spraying.
Mohammad Valipour; Afrasyab Rahnama; Payman Hassibi; Ali Monsefi
Abstract
IntroductionArid and semi-arid regions of the world are primarily characterized by water scarcity, which limits agriculture mainly to irrigated land. Presently and in the future, irrigated farming systems will have to operate under conditions of water scarcity, which significantly impacts food production ...
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IntroductionArid and semi-arid regions of the world are primarily characterized by water scarcity, which limits agriculture mainly to irrigated land. Presently and in the future, irrigated farming systems will have to operate under conditions of water scarcity, which significantly impacts food production and threatens global food security. Deficit irrigation is an important strategy involving the application of limited irrigation during drought-sensitive phenological stages of a crop. Water restriction is targeted at drought-tolerant growth stages, particularly the vegetative stages and late stages of ripening. The response of plants to deficit irrigation-induced water stress varies with growth stages and stress intensity. Deficit irrigation can maximize crop water productivity without significant yield loss, and various deficit irrigation strategies have been developed to improve crop performance under water deficit conditions. However, it is crucial to develop crop management strategies aimed at enhancing crop sustainability in stressful environmental conditions. Therefore, our study aimed to investigate the influence of different irrigation regimes at various growth stages on the morphological characteristics, and oil and grain yield of oilseed flax genotypes.Materials and methodsThis experiment was carried out during the 2022-2023 growing season, using a split-plot arrangement in a randomized complete block design with three replications. The study site was located at the research farm of Shahid Chamran University of Ahvaz, Iran. The main plots consisted of four irrigation regimes: control (irrigation at 80%, 80%, 80%, and 80% of field capacity), mild water deficit (irrigation at 60%, 70%, 70%, and 60% of field capacity), moderate water deficit (irrigation at 60%, 60%, 60%, and 60% of field capacity) and severe water deficit (irrigation at 40%, 50%, 50%, and 40% of field capacity). The sub-plots consisted of four oilseed flax genotypes: Isfahan, Kerman, Indian and Hungarian. Deficit irrigation treatments were applied at stem elongation, branching, flowering, and seed-filling stages. The control treatment was watered with sufficient water (80% field capacity) until the end of the experiment.Results and discussionThere were significant differences among genotypes and irrigation regimes in most traits. Deficit irrigation depend on plant growth stage and stress severity led to a significant reduction in the number of capsule per plant, the number of grain per capsule, grain number per plant, grain weight per plant, 1000-grain weight, plant height, branch number, biomass yield, harvest index, and grain and oil yield. The grain yield of all genotypes significantly decreased under mild, moderate and severe water-deficit stresses by 34%, 39% and 49%, respectively, compared to the control. Similarly, the oil yield reduced by 35%, 40%, and 52%, respectively, compared to the control. There was genetic variation in grain yield between genotypes in response to water deficit. Grain yield was significantly reduced for all genotypes in response to severe water-deficit stress, with larger reductions in Indian and Hungarian genotypes (56 and 62%, respectively) than Isfahan and Kerman genotypes (with 46 and 32%, respectively). The Isfahan and Kerman genotypes with higher grain yield exhibited a higher oil yield.ConclusionDifferent irrigation regimes applied at various growth stages had different effects on the morphological traits and yield of oil seed flax genotypes. The developmental stage and severity of water deficiency played an important role in the genotype responses to deficit irrigation management. The moderate deficit regime led to a 37% and 29% decrease in grain yield of Isfahan and Kerman genotypes, respectively, while saving about 35% of available water. Therefore, this deficit irrigation regime is recommended as a suitable strategy to improve water productivity. Moreover, Isfahan and Kerman genotypes are recommended for cultivation in semi-arid regions due to their greater stability in grain yield under deficit irrigation conditions.
Hamid Esmaili Khanbehbin; Mohammad Reza Dadashi; Mohamad Taghi Feyzbakhsh; Fatemeh Sheikh; Ali Nakhzari Moghaddam
Abstract
Introduction
Faba bean (Vicia faba L.) is a rich source of phosphorus, calcium, iron, and protein and is very effective in rotation, cropping patterns, and in maintaining the sustainability of agricultural systems and fixing atmospheric nitrogen through symbiosis. Achieving figures with high performance ...
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Introduction
Faba bean (Vicia faba L.) is a rich source of phosphorus, calcium, iron, and protein and is very effective in rotation, cropping patterns, and in maintaining the sustainability of agricultural systems and fixing atmospheric nitrogen through symbiosis. Achieving figures with high performance and a wide range of adaptation to drought stress and climatic changes is one of the most important breeding goals in Faba bean (Vicia faba L). This study was conducted to evaluate the effects of drought stress on grain yield and some biochemical traits of new Faba bean lines.
Materials and methods
This experiment was carried out in the crop year of 2022-2023 in the form of a split-plot experiment in the form of randomized complete blocks design with 3 replications at the Gorgan Agricultural Research Station. In this study, 9 low tannin lines of Vicia faba L along with two control cultivars Mehta (low tannin) and Shadan (high tannin) were compared and evaluated in two environments of drought stress (after flowering) and normal irrigation. The lines studied in this experiment were selected and cultivated from the superior lines of the preliminary faba bean experiments. Each experimental unit was in four lines with a distance of 60 cm, a length of 6 m and a plant distance on the row of 8 cm. In the normal irrigation environment (without stress), the time required for irrigation was based on weather conditions and the water requirement of the plant (sowing, before flowering, the beginning of flowering and seed filling) in four irrigation times so that the plant does not face drought stress, but in the drought stress environment, no irrigation was done from the beginning of flowering to the end of the growing season.
Results and discussion
The results of composite variance analysis (mean square) showed that the interaction between drought stress and variety on chlorophyll b, total chlorophyll, proline, soluble sugar, carotenoid, number of branches per plant and number of pods at a statistical level of 1% and on chlorophyll a and weight Seed dryness in the plant was significant at the five percent level. Comparison of the average interaction between drought stress and variety showed that Shadan variety and lines BPL4104, WRB1-3, FLIP03-07FB had the highest seed yield per hectare with 5100, 4950, 4750, 4633 kg respectively. Also, in the conditions of drought stress, FLIP03-07FB, WRB1-3 and Shadan varieties had the highest production of 500, 473 and 437 kg of seed yield per hectare, respectively. In the normal environment, Shadan variety had the highest amount of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid at 1.53, 0.46, 0.2 and 0.58 mg g-1 respectively, and the line FLIP03-07FB with 9.47 μmol ml-2 had the most proline and line S2008,033 with the amount of 1.16 mg per gram had the most soluble sugar. The highest number of seeds per pod (3.28) was obtained in normal environment and the lowest number of seeds per pod (0.303) was obtained in drought stress environment. Identifying drought-resistant cultivars at the end of the season is one of the strategies for developing faba bean cultivation in the country. Drought stress during flowering and pod formation reduces the transport of photosynthetic materials, resulting in grain shrinkage, reduced grain weight, and reduced grain yield, while lack of stress during the flowering stage increases the length of the grain filling period, increases grain weight, and grain yield.
Conclusion
According to the results, it can be stated that drought stress in the flowering and seed filling stage caused a decrease in seed yield and an increase in carotenoid, proline and soluble sugar levels in all cultivars. Shadan variety and lines WRB1-3 and FLIP03-07FB had the highest seed yield in both environments. Therefore, the cultivation and development of two new lines are suggested after carrying out compatibility tests in different regions of the country and achieving the stability of seed yield.
Mansoureh Tashakorizadeh; Pooran Golkar; Mohammad Reza Vahabi
Abstract
Introduction
Copper (Cu2+) is an essential element for the plant's metabolic processes, which is required by the plant for many enzymatic activities and playing a vital role in various physiological processes, growth, and development in small amounts. On the other hand, high concentrations of ...
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Introduction
Copper (Cu2+) is an essential element for the plant's metabolic processes, which is required by the plant for many enzymatic activities and playing a vital role in various physiological processes, growth, and development in small amounts. On the other hand, high concentrations of copper can be toxic to plants and high accumulation of this element in the soil prevents the elements needed for growth from reaching the aerial organs and prevents the normal growth of the plant. Drought stress also disrupts the growth and water relations in the plant and leads to a decrease in the efficiency of water consumption in the plant and causes a variety of physiological responses along with yield reduction. Soil contamination with heavy metals adversely affects plants growth, its development and metabolism in many parts of the world including arid and semi-arid regions. Multiple stresses caused a wide range of changes in plant physiology and metabolisms in plants. Fumaria parviflora Lam (Fumariaaceae) is an annual herbaceous medicinal plant with branched stems that is cultivated in arid and semi-arid regions of Iran.
Materials and methods
This study was conducted as a factorial experiment based in a completely randomized design in greenhouse conditions with three replications. In this study, the independent and combined effects of different concentrations of copper element (control, 50, 150, 300 and 400 mg kg-1) and different levels of drought stress (control, 50% and 75% based on soil moisture percentage discharge) was investigated on seed yield, malondialdehyde, soluble carbohydrates, proline, total anthocyanin content, total phenolics content, total flavonoids content, and antioxidant activity of Fumaria Parviflora Lam. The seeds of the plant were collected from two mining areas (Askari ravar and Rabor) from four zones (Z1, Z2, Z3 and Z4) in Kerman province.
Results and discussion
The results of this study showed that the lowest amount of total phenoolics (89.3 mg GAE g-1 DW) and total flavonoids (8.1 mg QE g-1 DW) content was observed in the control treatment and the highest amounts for total phenolics (123.2 mg GAE g-1 DW) and total flavonoids (14.7 mgQE g-1 DW) were observed in severe drought stress. Here, the independent and combined effects of different concentrations of copper element and drought stress showed an increasing effect the biochemichal traits. The interaction effect of 50 mg kg-1 of copper on drought stress was decreasing in grain yield, proline and anthocyanin content. At a concentration of 150 mg kg-1, the copper element had an increasing effect on the drought stress for proline content, amount of soluble carbohydrates and anthocyanin content. The interaction effects of copper and drought stress showed that in concentrations of 300 and 400 mg kg-1, copper has an increasing effect in the presence of drought stress for proline, anthocyanin, total phenolics, total flavonoids, antioxidant activity and malondialdehyde content, but had a reducing effect on soluble carbohydrates.
Conclusion
This study was studied by the first time on the combined effects of a heavy metal and drought stress on F. parviflora. Under moderate drought stress, F. parviflora Lam. was able to withstand the stress up to the concentration of 150 mg kg-1 of copper by using defense mechanisms. Also, the areas with high concentration of copper (Z3 and Z4) in the studied mining areas were more tolerant to high copper stress and showed higher grain yield than the areas with lower concentration of copper (Z1 and Z2). The findings confirmed the use of F. parviflora as a suitable species for soils contaminated with low to moderate copper (50-150 mg kg-1) under moderate drought stress. Based on these findings, it can be concluded that F. parviflora can deal with copper stress due to its active antioxidant defense system. It is possible to collect the seeds of this plant from areas with high concentration of copper (300 and 400 mg kg-1) for the cultivation of F. parviflora under contaminated areas with copper stress.
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