Meisam Ghavampoor; Seyyed Gholamreza Moosavi
Abstract
Introduction Iran with mean annual precipitation of 240 mm is categorized in arid zones of the world. High evapotranspiration, limited water resources and other parameters invokes the interests for studying the effect of water stress in field crops. Also, N fertilization and plant density were ...
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Introduction Iran with mean annual precipitation of 240 mm is categorized in arid zones of the world. High evapotranspiration, limited water resources and other parameters invokes the interests for studying the effect of water stress in field crops. Also, N fertilization and plant density were important factors for growth and production of field crops. Management of balanced and efficient use of fertilizers is certainly necessary to obtain maximum yield. Plant deficit per unit area prevents maximum usage of production parameters and on the other hand, excessive density can increase the competition and decrease the yield. The objective of the present study was to examine the influence of the plant density and N application levels on yield and yield components of Eruca sativa under late-season water deficit stress in Birjand, Iran. Materials and Methods This research was carried out in the research farm of Islamic Azad University of Birjand, Iran in 2013-2014 in a factorial split-plot experiment on the basis of a Randomized Complete Block Design with three replications. The main plot was devoted to irrigation at two levels of no stress (optimum irrigation) and stop irrigation in reproductive stage, the sub-plot was devoted to plant density at two levels of 50 and 150 plants m-2 and N fertilization at three rates of 0, 100 and 200 kg N ha-1 as factorial. In optimum irrigation treatment, the farm was irrigation with the intervals of 9 days during whole growing season. The N demand of the plots in terms of N fertilization levels was supplied at the first irrigation after final thinning of the plants in late-March from urea source. The texture of the soil in research farm was loam with the pH of 7.79, electrical conductivity of 7.23 mmos/cm whose organic carbon, total N, P, and K content was 0.17%, 0.04%, 15.4 ppm and 266 ppm at the depth of 0-30 cm, respectively. In the end, all data were analyzed by MSTAT-C statistical software and means were compared by Duncan Multiple Range Test at 5% level. Results and Discussion Analysis of variance revealed that seed yield was significantly influenced by irrigation, plant density, N fertilization and the interaction between irrigation and N and between irrigation, plant density and N. The interaction between irrigation and plant density was significant for seed number per pod, pod number per m2 and pod number per plant. The interaction between irrigation and nitrogen was significant for pod number per m2, pod number per plant, seed yield and biological yield. The interaction between plant density and nitrogen was significant for pod number per plant and biological yield. Also, the interaction between irrigation, plant density and nitrogen was significant for seed yield and biological yield. The results showed that stop irrigation in reproductive stage increased pod number per m2, pod number per plant, 1000-seed weight, seed yield and biological yield, 60.1, 51.3, 23.6, 68.5 and 62.7%, respectively. Also, the increase in plant density from 50 to 150 plants. m-2 increased pod number per m2, seed yield and biological yield 41.5, 29.5 and 41.9%, respectively and decreased pod number per plant 36.49%. Moreover, the increase in nitrogen application from 0 to 200 kg N ha-1 increased pod number per m2, pod number per plant, seed yield and biological yield 91.8, 68.3, 70.2 and 55 %, respectively. Means comparison for the interaction between irrigation and N revealed that the highest seed yield (174.27 g m-2) was produced under the treatment of optimum irrigation fertilized with 200 kg N ha-1 and the lowest one (41.78 g m-2) under the treatment of water deficit stress at reproductive stage with no application of N fertilization. In other words, at under optimum irrigation, E. sativa was able to use N more effectively for increasing seed yield. It implies that the necessary condition for appropriate efficiency of N use is the availability of enough moisture in root zone so that soil N content can readily be available to plant and is used for inducing vegetative growth, photosynthesis and seed yield enhancement. Furthermore, means comparison for the interaction between irrigation, plant density and N showed that the highest seed yield (193.30 g m-2) was produced under the treatment of optimum irrigation at the density of 150 plants m-2 fertilized with 100 kg N ha-1 and the lowest one (33.67 g m-2) under the treatment of water deficit stress at reproductive stage at the density of 50 plants m-2 and no application N fertilization. Seed yield variation under optimum irrigation is tangibly affected by the variations of plant density and N, while the treatment of water deficit stress at reproductive stage did not result in significant changes in seed yield between various levels of density and N rate, so that all density levels and N rates were ranked in the same statistical group. Conclusions Generally based on means comparison of interaction effects, it is recommended to use the density of 150 plants m-2 optimally irrigated and fertilized with 100 kg N ha-1 for cultivation Eruca sativa because of its optimum seed yield and which takes environmental issues under consideration too.
Saeed Sadeghzadeh Hemayati; Daryoush Fathollah Taleghani; Parviz Fasahat
Abstract
Introduction Water stress is considered as one of the most widespread limitations to crop productivity and yield stability. In sugar beet, drought causes yield reductions between 10 and 30 %, which is increased in arid and semiarid regions. A solution is to improve the drought tolerance of sugar beet ...
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Introduction Water stress is considered as one of the most widespread limitations to crop productivity and yield stability. In sugar beet, drought causes yield reductions between 10 and 30 %, which is increased in arid and semiarid regions. A solution is to improve the drought tolerance of sugar beet varieties and to identify sugar beet germplasm that is drought-tolerant and high yielding so that it can be included in future breeding programmes. Materials and methods To evaluate the effects of drought stress on qualitative characteristics of sugar beet including sugar content, Na, K, N, alkalinity coefficient, molasses sugar, root dry matter, canopy ground cover and wilting score of 36 sugar beet genotypes, a study was conducted in split plot based on randomized complete block design with three replications in Kamal-Abad station in Sugar Beet Seed Institute, Karaj in 2012. Main plots were allocated to two irrigation systems including normal and water stress and sub-plots were assigned to sugar beet genotypes including 29 o-type lines, developed from 7221, 110 and 111 seed bulks (BC1F2), as well as susceptible and resistant controls. Class A evaporation pan was used to measure evaporation. Irrigation was conducted after 80-90 and 270 mm evaporation from evaporation pan under normal and stress conditions. Each plot consisted of one planting raw with 8 m length and an interrow spacing of 0.5 m. During the growing season, number of plants after establishment, growth score, and growth uniformity were recorded. Canopy ground cover, wilting score and plant death were measured in three stages. Canopy ground cover was measured using a 0.25 m2 quadrat and wilting and senescence scores were measured at 11-13 am. Qualitative characteristics such as sugar content, white sugar content, sodium, potassium, nitrogen, alkalinity coefficient, molasses sugar and root dry matter were measured at harvest. Results Drought stress and genotype had significant effect (P<0.01) on canopy ground covering. With increasing irrigation frequency from 90 to 270 mm evaporation, drought stress reduced canopy ground cover from 57 to 38% and accelerated the green ground cover reduction from 81 to 67 days after sowing. Drought stress, scoring time, and their interaction had significant effect on wilting score but no significant effect was observed among genotypes. Under normal condition, 116 days after planting, wilting score increased 97% compared with 87 days after planting. However, under stress condition, 87 days after planting, wilting score increased 51% compared with 116 days after planting. In addition, drought stress increased senescence score (1.90) as compared to normal conditions (1.54 and 1.50, respectively). Furthermore, sugar content and white sugar content were decreased by 33 and 43%, respectively whereas root Na content and molasses sugar were significantly increased by 23 and 13%, respectively. Conclusion With consideration of all qualitative indices including sugar content and white sugar content, root impurities, alkalinity coefficient and molasses sugar, genotypes 1 and 30 for all six traits, and genotypes 10, 28, 31 and 33 for five traits, and genotypes 8, 12, 27, 34, and 35 for four traits had more optimum level than the other genotypes.
Roghayeh Aminian; Maesomeh Paknejad; Seyed Mohsen Hoseini
Abstract
Introduction Plant oil is one of the basic human food needs. Due to the increasing population,increase the area under crop cultivation and enhance the performance of them is essential. Increase of oil yield is primarily associated with increase in seed yield. The importance of oil crops such as safflower ...
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Introduction Plant oil is one of the basic human food needs. Due to the increasing population,increase the area under crop cultivation and enhance the performance of them is essential. Increase of oil yield is primarily associated with increase in seed yield. The importance of oil crops such as safflower has increased in recent years. Safflower has the special place in Iran because it shows high compatibility with the country's climate. Drought stress is one of the most important environmental stresses affecting agricultural productivity around the world and may result in considerable yield reductions. Safflower (Carthamus tinctorius L.) is a tap-rooted annual crop which can tolerate environmental stresses including salinity and water stress. In most plants, the time during flowering to seed developments are sensitive to water deficit. Nanoparticles can facilitate effective absorption of fertilizers at Nano scale. Furthermore nanoparticles can facilitate enhanced ability of water absorption by roots, and increase antioxidant enzyme activity such. Thus, nanoparticles can increase plant resistance against different stresses. Titanium dioxide nanoparticles are used in agriculture to increase growth and yield, improve the rate of photosynthesis and reduce disease. The application of TiO2 has been found to show excellent efficacy in wheat, soybean, Lentil and spinach This study aimed to investigate the effect of foliar application of Nano Tio2 on yield and yield components of safflower genotypes under normal and low irrigation. Materials and methods To study the effect of Tio2 Nano particles spraying on yield and yield components of safflower genotypes under normal and low irrigation conditions, a split factorial experiment was conducted in randomized complete block design with three replications in the research field of Imam Khomeini International University, Qazvin, in 2014. Irrigation regime includes regular watering (irrigation after 60 mm evaporation from class A evaporation pan) and low irrigation (watering until late flowering similar to normal irrigation and late flowering to maturity, irrigation after 100 mm evaporation from class A evaporation pan) were considered as the main factor. Tio2 in two levels, including the use of Tio2 (0.05 percent concentration before flowering) and non-use (control) and genotypes in eight levels including Kuseh Local, Sina, Isfahan Local, Mexican 88, Faraman, Soffe, Goldasht, Mexican 11 were considered as sub-factors. In this experiment traits number of heads per plant, number of seed per head, head diameter, 1000 grain weight, harvest index and grain yield were studied. Results and discussion The irrigation effect was significant for traits 1000 grain weight, harvest index and grain yield. Low irrigation stress reduced the number of heads, head diameter, 1000 grain weight, harvest index, and grain yield. In other experiment water stress caused plant height, number of heads and grain yield decreasing in safflower. The effect of Tio2 utilization was significant on head diameter, harvest index and grain yield. Tio2 increased head diameter, harvest index and grain yield as well as significantly reduced the adverse effect of low irrigation stress on head diameter. The other research results on effects of different Nano titanium dioxide concentrations (0.01, 0.02, and 0.03 percent) and titanium dioxide (bulk) spray treatment on barley plants showed that traits of grain yield, number of ears and harvest index in all treatments of Nano titanium dioxide application were more effective than the control treatment. The Irrigation and Nano Tio2 interaction effect was significant for grain yield. Nano Tio2 particles increased grain yield only in normal irrigation. Nano-titanium dioxide is likely to increase grain yield through improving light absorption and increasing the efficiency of photosynthesis. Genotype differences for all traits except head diameter were significant. Although the highest grain yield was obtained from Faraman, Sina and Isfahan Local were not significantly different from Faraman. The lowest grain yield was belonged to Mexican 11 and Mexican 88. Conclusions The results demonstrated that low irrigation stress caused significant reduction in 1000 grain weight, harvest index and grain yield. The seed weight is an important component of yield and due to decreasing in seed weight grain yield decreased. The adverse effect of stress on head number, reduced by application of Tio2 although, Tio2 effect was not significant for other traits in stress condition. The plant growth stage and concentration of Tio2 are also important and they are different for different plants or even for different characteristics. Generally, Faraman, Sina, Isfahan Local had the highest performance in Qazvin climate.
Farzad Paknejad; Zinab Fatemi Rika; Mohamad Elkaee Dehno
Abstract
Introduction Barley (Hordeumvulgare) is one of the most important crops in the world. Water deficit at each growth stage of crop leads to a reduction in the different levels of yield. The amount of this decrease depends on many factors such as time, duration and severity of the stress period. Today’s ...
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Introduction Barley (Hordeumvulgare) is one of the most important crops in the world. Water deficit at each growth stage of crop leads to a reduction in the different levels of yield. The amount of this decrease depends on many factors such as time, duration and severity of the stress period. Today’s using suitable barley cultivars under drought stress is important in increase economical yield due to the importance of stage of barley under stress, the aim of this study was to investigate the effects of terminal drought stress on yield and yield components of different barley varieties. Matreials and methods This research was conducted in the field of research of Islamic Azad University, Karaj Branch (latitude 35 ° 43'N, longitude 50 ° 49 'East) at the altitude of 11784 m above sea level with an average annual rainfall of 251.2 mm. This site had a clay loam texture. EC, pH and saturated moisture content were 33.3 dS,7.4 and 36%. a split-plot based on randomized complete block design with four replications was carried out. The main plots consisted of two levels: normal irrigation and water stress (irrigation after spike emergence) and subplots including 10 barley cultivars, Valfajar, Basil, Kavir, Zarjoo, Goharjoo, Karoon, Dasht, Turkmen, Nosrat and Yousef. Each experimental plot included 8 sowing lines with a length of 8 meters spacing between lines of 15 cm. 3 meters between main plots and .05 meter between subplot. The first irrigation was carried out immediately after planting. Also, traits such as grain yield, total dry matter, harvest index, 1000 grain weight, number of seeds per spike, number of spikes per unit area, grain weight per spike, plant height and peduncle length were measured. SAS software (V.9) was used to analyze statistics. The comparison of the means was performed using Duncan multiple tests at a significant level of 5%. Results and discussion According to obtained results drought stress caused significant decreasing on grain yield, total dry weight, 1000 grain weight, ear number per unit area, grain weight per ear, plant height and peduncle length and harvest index. Highest grain yield obtained in full irrigation condition relevant to Kavir (7781.5 kg/ha) and Nosrat (7414.8 kg/ha) cultivars also Goharjo cv. in both full irrigation and drought condition produced grain yield 2685.2and 1962.8 kg/ha, respectively.In addition, Kavir cv. with reduction 46.36% and Dasht cv. with reduction, 2.34% of grain yield have highest and lowest sensitivity to drought, respectively. Grain yield showed positive correlation to some traits such 1000 grain weight, ear number per unit area, harvest index, plant height and peduncle length. Also, the highest correlation of grain yield relevant to harvest index (r = 0.74) and total dry matter (r = 0.67), respectively. The cultivar of Dasht had the highest number of spikes per unit area and cultivar GoharJo had the least number of spike per square meter (1181.78, 234.28, respectively). Stress condition had not a significant effect on number of grain per spike, but cultivars had a significant effect on this trait so that the highest number of seeds per spike was shown in Basil cultivar (45.7 seeds) and the lowest of it was shown in Dasht (16.08 seeds). In this regard, the Kavir cultivar has a loss of 36.66% yield in stress conditions and Dasht cultivar have a decreasing of 34.2% with the least susceptibility. Conclusions Kavir cultivar has a reduction of 36.66% of grain yield with the highest susceptibility to stress and cultivar of Dasht have a decrease of 34.2% grain yield and shown the least susceptibility to stress. The highest correlation was observed between grain yield and harvest index (r = 0.74) and total dry matter (r = 0.67).
Mojdeh Jamali; Farshid Ghaderi-Far; Hamid Reza Sadeghipour; Elias Soltani; Seyed Majid Alimagham
Abstract
Introduction Hydrotime model and its coefficients are used to investigate the relationship between water potential and germination rate and percentage. The coefficients of this model puts seed quality indexes such as speed and uniformity of germination and tolerance to environmental stresses at the disposal ...
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Introduction Hydrotime model and its coefficients are used to investigate the relationship between water potential and germination rate and percentage. The coefficients of this model puts seed quality indexes such as speed and uniformity of germination and tolerance to environmental stresses at the disposal of researchers. The reducing of water potential significantly decreased seed germination percentage, the chance of plant establishment, uniform emergence, germination rate and seed yield. On the other hand, has been reported that priming increases seed germination in stressful conditions such as salinity, drought and temperature stresses. The coefficients of hydrotime model can be also used for assessment of reaction of wheat deteriorated seeds to drought stress, and indicated that priming improved which germination components of wheat deteriorated seeds. According to these, the aim of this study was to evaluate the germination of deteriorated seeds of wheat under drought stress by Hydrotime model and its coefficients evaluation and comparison at different levels of deterioration and priming. Materials and methods This study conducted in seed research laboratory of Gorgan university of Agricultural Sciences and Natural Resources in 2012. In this experiment, wheat seeds of cv. Koohdasht with different levels of vigor were used. For creating different levels of seed vigor, natural deteriorated seeds (two years of storage) and artificial deteriorated seeds (0, 48, 96 and 120 hours at 43 ° C) were used in two priming and no priming conditions. Priming performed with the use of gibberellic acid in 50 ppm. Different levels of water potential obtained by using polyethylene glycol 6000 in four levels included 0, -0.6, -1.2, and -1.8 MPa. Finally, the hydrotime model (θH=[ψ - ψb(g)]× tg) was used to study the reaction of deteriorated seeds of wheat to drought stress and the effects of priming on improving seed germination. Results and discussion The results showed that hydrotime coefficient (θH) increased by increasing in seed deterioration (either artificial or natural) in terms of both primed and control seeds, In other words, the germination rate was decreased. But, the reduction in germination rate in primed seeds was lower than non- primed seeds. So that, the hydrotime coefficient increased at a rate of 14.8 MPa hours by seed deterioration per day in the primed seeds, But in the control seeds this index increased at a rate of 29.6 MPa hours by seed deterioration per day. In fact, priming compared to control treatment reduced the hydrotime coefficient and increased germination rate of deteriorated seeds especially in severe deterioration. Increase percentage of this coefficient in the natural deteriorated seeds was lower than artificial deteriorated seeds, and this suggests that intensity of artificial deterioration is more than natural deterioration. Thus, the damage that caused by artificial deterioration is more than natural storage. In addition, the model output showed that increase in deterioration significantly reduced the uniformity of seed germination (increase ψσb), But priming had not significant influence on seed germination uniformity. Stored seeds has less germination uniformity compared to non-deteriorated seeds (more ψσb). In priming treatments, was not observed any change on this coefficient by increased duration of deterioration to 3.12 days. But with increasing duration of deterioration more than 3.12 days, its value increased, which suggested that priming did not have a positive impact on improving drought resistance. But resistance to drought reduced significantly in severe deterioration conditions. By increasing the duration of deterioration after 3.12 days, increased 4.0 MPa per day. In control treatment, variation of Ψb(50) to deterioration period was different compared to priming. By increasing deterioration to 1.99 days in control, this coefficient was more negative (increased drought resistance). With increasing duration of deterioration, the value of this coefficient increased after this period. Also, priming has not significant effect on Ψb(50) in natural storage conditions. For natural deterioration during two years, the value of Ψb(50) has not significant difference with not deteriorated seeds (for both priming and control). Conclusions Generally these results showed that the deterioration cause decrease of rate, uniformity and drought resistance, and priming only increases the germination rate and no effect on the other components.
Mojtaba Hosseini; Mehdi Nojab; Gholan Reza Zamani
Abstract
Introduction Germination is an important critical phenomenon which is influenced by weeds. This growth stage indicates the first stage as weed might be a competitor for ecological niche. This process of germination is influenced by several environmental factors such as light, temperature, salinity, pH ...
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Introduction Germination is an important critical phenomenon which is influenced by weeds. This growth stage indicates the first stage as weed might be a competitor for ecological niche. This process of germination is influenced by several environmental factors such as light, temperature, salinity, pH and soil moisture. Knowledge about the pattern of germination and emergence of weed species can provide useful information for the future development of management strategies. Salt and drought stresses are among constraints for plant growth and development. Wild barley )Hordeum spontaneum Koch.) is an annual winter weed from poaceae family. It enumerates ancestor barley (Hordeum vulgare) which is sharply spreading in wheat fields in Iran. Climate conditions of Iran showed a dramatic spread of wild barley on wheat field, vital role of water potential on germination stage and no enough information about wild barley germination; This experiment was designed to evaluate the effect of salt and drought stresses on wild barley germination and early growth in comparison with wheat. Materials and Methods In order to assess the effects of different salt and drought stress levels on germination and early growth of wheat (Triticum aestivum) and wild barely (Hordeum spontaneum). Four experiments were conducted in growth chamber at the Advance Research Laboratory, Faculty of Agriculture, The University of Birjand. Treatments were four levels of drought and salt stress that created by PEG 6000 and NaCl respectively (-0.3, -5, -10 and -15 bars and distilled water as control). Salt stress were created using NaCl based on the Vant Hoff formula and drought stress were created using polyethylene glycol (PEG600), based on the Michel formula. The seeds were disinfected by sodium hypochlorite, 2% for a minute and then washed with distilled water. Four replications of 25-seeds of wheat and wild barely were placed in 9-cm Petri dishes lined with two discs of filter paper, moistened with either 10 ml demonized water or treatment solution when required. The Petri dishes were sealed with Parafilm to minimize evaporation and placed directly in the germinator. The number of germinated seeds recorded daily until the end of the germination test. Seeds were considered to have germinated when the radical emerged. Each treatment measured radical fresh weight, plumule fresh weight, radical length, plumule length A functional three-parameter logistic model was fitted to the germination values (percentage) obtained at different concentrations of NaCl or PEG for both wheat and wild barely using SigmaPlot . Results The results revealed that as increase in salt and drought stresses significantly decreased the percentage of germination, germination rate, seedling fresh weight, radicle fresh weight, plumule fresh weight and radicle and plumule length in wheat and wild barely. In order to, evaluation the effect inhibition of salt and drought stresses did apply orthogonal contrast between wheat and wild barley on percentage germination, germination rate, radical length and seedling fresh weight. Orthogonal comparison in two stresses showed that percentage of germination, germination rate, root length and seedling fresh weight of wild barely decreased more than wheat. The functional three-parameter logistic model showed that, salinity at -10.82 and -6.40 bar, respectively caused 50 percent maximum germination percentage of wheat and wild barley and drought stresses at -12.82 and -5.20 bar respectively, caused 50 percent maximum germination percentage of wheat and wild barley. Decreasing in germination rate in salt and drought stresses were similar to germination percentage. Decrease of germination rate was recorded 76.08 and 100 % in salt stress in wheat and wild barely respectively, and 74.60 and 100 % respectively in wheat and wild barely in drought stress. Conclusion Overall, result showed that wild barely was more sensitive to salt and drought stresses as compared to the wheat.
Razieh khalilzadeh; Raouf Seyed Sharifi; Jalal Jalilian
Abstract
Introduction Soil salinity is one of the most serious limiting factors for crop growth and production in the arid and semi-arid regions due to increasing use of poor quality of irrigation water. Salt stress is known to affect many physiological activities related to the accumulation of ions and osmolytes ...
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Introduction Soil salinity is one of the most serious limiting factors for crop growth and production in the arid and semi-arid regions due to increasing use of poor quality of irrigation water. Salt stress is known to affect many physiological activities related to the accumulation of ions and osmolytes such as proline. Several strategies have been developed in order to decrease the toxic effects caused by high salinity on plant growth. Among them, use of bio-fertilizers such as plant growth promoting rhizobacteria (PGPR) plays a very important role in yield improvement. Inoculation of plants with native suitable microorganisms may decrease the deleterious effects of environmental stresses and increase stress tolerance of plants by a variety of mechanisms, including synthesis of phytohormones such as auxins, cytokinin and gibberellins, solubilization of minerals like phosphorus, production of siderophores and increase in nutrient uptake, N2 fixation. Cycocel is an essential growth regulator for plants that reduced concentration of gibberellins and interfere with the concentration of other plant hormones such as cytokinins, ethylene, and abscisic acid, which can affect physiological processes. Better understanding of wheat l responses under salinity may help in programs in which the objective is to improve the grain yield under salinity levels. Therefore, the aim of this study was to evaluate the effects of bio fertilizers and cycocel on yield and some agro-physiological traits of wheat under salinity stress conditions. Materials and Methods In order to study the interaction cycocel and bio- fertilizers on yield and some agro-physiological traits of wheat at soil salinity condition, a factorial experiment based on randomized complete block design with three replications was conducted in research greenhouse of the Faculty of Agriculture, University of Mohaghegh Ardabili in 2015 growing season. Experimental factors were soil salinity at four levels (0 as control, 30, 60 and 90 mM) as NaCl and seed inoculation with bio- fertilizers in four levels (without inoculation as control, seed inoculation with Azotobacter chrocoocum strain 5, Pseudomonas putida strain 186 and Azotobacter+ Pseudomonas) and foliar application of cycocel at three levels (0, 600, and 1000 mg.L). Results The results showed that the effects of salinity, cycocel and bio-fertilizers were significant on grain filling period, grain yield and yield components. The highest grain yield (2.47 g) was obtained from foliar application of 1000 mg.L cycocle × seed inoculation with Azotobacter +Pseudomonas and the least of it (1.98g) was obtained to non-application of cycocle, non-inoculated seed treatment. Interaction effect between salinity and bio fertilizers showed that the highest grain yield (2.65 g per plant) was obtained in no salinity with Azotobacter+ Pseudomonas application and the least it (1.74 g per plant) was obtained in the highest salinity level (90 Mm) and without application of bio fertilizers. Foliar application of 1000 mg.L cycocel, seed inoculation with Azotobacter + Pseudomonas under no salinity condition had the highest ear length (10.25 cm), 100 grain weight (5.3 g) and grain filling period (43.26 days). Maximum of grain filling rate (0.002 g/day) was obtained in inoculation with Azotobacter +Pseudomonas under no salinity condition. Leaf area index increased slowly at all treatment combinations until 35 days after sowing (DAS), then increased rapidly till 65 DAS. Then it decreased till harvest time due to aging of leaves. The highest leaf area index (LAI) was obtained in 65 DAS and Azotobacter+ Pseudomonas application and without application of cycocel and salinity. The least it was obtained in application of 1000 mg.L cycocel and without application of bio fertilizer at the highest salinity level. 30 and 60 mM salinity levels had little effect on chlorophyll content and stomatal conductance. The highest level of cycocel and seed inoculation with Azotobacter+Pseudomonas showed the highest SPAD and stomata conductivity under no salinity stress. Conclusion Generally, it can be suggested that foliar application of 1000 mg.lit-1 cycocel and seed inoculation with Azotobacter+Pseudomonas increased about 20% from grain yield in comparison with control and both inoculation of Azotobacter+Pseudomonas compensated about 15% of yield reduction due to salinity.
Semira Moravveji; Golam Reza Zamani; Mohammad Kafi; Zohre Alizadeh
Abstract
Introduction Salinity is one of the most important abiotic stresses that makes large areas of arable lands substantially or partially unproductive (Ashraf and McNeilly, 2004) and generally causes slowed plant growth rate, smaller leaves, reduced plant height and economic yield (Steppuhn and Raney, 2005). ...
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Introduction Salinity is one of the most important abiotic stresses that makes large areas of arable lands substantially or partially unproductive (Ashraf and McNeilly, 2004) and generally causes slowed plant growth rate, smaller leaves, reduced plant height and economic yield (Steppuhn and Raney, 2005). Two oilseed amphidiploids Brassica species including canola (Brassica napusL.) and Indian mustard (B. junceaL.) are relatively salt tolerant amongst oilseed crops. This experiment was conducted to evaluate seed yield, oil yield and yield components of two spring canola cultivars (Hyola 401 & RGS003) and Indian mustard and to compare these genotypes under irrigation with different salinity levels. Materials and Methods This experiment was conducted as factorial based on randomized complete block design (due to lack of uniformity of the light) with three replications in the Research Greenhouse of Agriculture Faculty, University of Birjand, in 2015. The first factor consisted of four salinity levels including 1.9 (Hoagland solution as control), 5, 10 and 15 dS/m (NaCl in Hoagland solution) and the second one was genotype consisting of two spring canola cultivars (Hyola401 and RGS003) and Indian mustard landrace. The medium was sand culture in pots with 8 plants per 0.123 m2square-sahped cross section pot. Pots were irrigated from planting to emergence stage with distilled water and thereafter with Hogland solution using gravity drip irrigation system. At four-leaf stage, by adding sodium chloride to Hoagland solution, salinity stress was gradually started and continued until the end of maturity. At the end of every two weeks, pots were leached to avoid excessive accumulation of salts. At physiological maturity for each genotye, two randomized selected plants were harvested from each pot to determine seed yield and yield components. Seed oil percentage was measured using Soxhlet extractor (AOAC, 1990) and oil yield was calculated with multiplication of seed oil percentage by seed yield. Seed protein percentage was determined by the Kjeldahl method (Licitra et al., 1996). Data analysis and statistical calculations were done using SPSS and EXCEL softwares. Mean comparisons were accomplished according to FLSD Test, at 5% probability level. Results and Discussion Analysis of variance on data demonstrated that the main effect of salinity and genotype on protein percentage and interaction effects of salinity and genotype were not significant on biological yield, while on all other traits were significant at 1% probability level. Results showed that by rising irrigation salinity up to 15 dS/m, amongst all seed and oil yield components the greatest and lowest significant reduction percentage compared to the control, were observed with the number of fertile pods per plant and seed oil percentage , respectively. Mean comparison of evaluated traits illustrated that Hyola 401 had the lowest amount of number of pods per plant and fertile pods per plant and possesed the highest amount of traits including 1000- seed weight and seed oil percentage which were significantly different from those of RGS003 and Indian mustard. Indian mustard in response to different salinity levels, with significant difference in comparison to canola cultivars, showed the lowest amount of evaluated traits including seed number per pod, 1000- seed weight and biological yield. RGS003, with significant difference in comparison to other genotypes, had the highest biological yield. The lowest seed yield of all genotypes was observed with the highest salinity level with a reduction of 73.31, 55.15 and 67.61 percent relative to control, which were achieved with Hyola 401, RGS003 and Indian mustard, respectively. There were not significant differences in oil yield between genotypes in salinity level of 15 dS/m, whereas in other levels Hyola 401 indicated a significant advantage. Correlation analysis of different traits showed that the most effect of salinity on oil yield in canola cultivars and Indian mustard was related to seed yield (r= 0.97**), biological yield (r= 0.75**), 1000- seed weight (r= 0.76**), number of seeds per pod (r= 0.74**), oil percentage (r= 0.64**) and harvest index (r= 0.59**). Conclusion Among the applied salinity treatments, the salinity level of 15 dS/m had the greatest effect on reducing studied traits. Seed and oil yield of Hyola 401 in comparison to two other genotypes showed significant advantage in low levels of salinity. However increased salinity level, resulted in a downward turn in yield differences, so that, at 15 dS/m no significant differences were observed.
Maesomeh Alizadeh Forutan; Hemmatollah Pirdashti; Yaser Yaghoubian; Valiollah Babaeizad
Abstract
Introduction Green bean (Phaseolus vulgaris L.) is one of the four species of the genus Phaseolus with the highest protein among a variety of commercial plants (Nasri and Khalatbari, 2011(. This plant can be grown in different times in Mazandaran weather conditions (Motaghian et al., 2010). Green beans ...
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Introduction Green bean (Phaseolus vulgaris L.) is one of the four species of the genus Phaseolus with the highest protein among a variety of commercial plants (Nasri and Khalatbari, 2011(. This plant can be grown in different times in Mazandaran weather conditions (Motaghian et al., 2010). Green beans as well as other crops during their growth stages faced with environmental stresses such as chilling. Chilling stress referred to conditions as temperature between 0 and 10 ᵒC which resulted in damages to the plant (Baninasab, 2009). Chemical and biological inducers can be used to increase chilling stress tolerance of plants. Paclobutrazol (PBZ) is a member of the Tryazol families with growth regulating effect (inhibitors) and increased stress tolerance through changes in plant growth and morphological, anatomical and biochemical changes (Berova et al., 2002; Chaturvedi et al., 2009). Meanwhile, Piriformospora indica fungus is one of the soil microorganisms which form a symbiotic relationship with plants and could increase plant growth and resistance to environmental stresses throughout systemic changes or defense induction (Deshmukh et al., 2006). Hence, the present research was aimed to determine PBZ and P. indica efficiency in green bean tolerance against chilling stress. Materials and Methods The experiment was conducted under controlled conditions at Genetics and Agricultural Biotechnology Research Institute, Sari Agricultural Sciences and Natural Resources University in factorial arrangement based on completely randomized design with three replications in 2013. Treatments were three levels of chilling stress (control, three and six days exposure to five centigrade degree temperature), two levels of fungi inoculations (control and inoculation with P. indica) and three levels of PBZ (0, 40 and 80 mg/L). To inoculate the plants with P. indica, fungal spore suspension was prepared (5×105 spore/ml). The sprouted seed were soaked for four hours in fungal suspension and were sown in pots containing two kg of sterilized soil. PBZ was sprayed twice at two stages of five and six week after sowing. Then pots were transferred to growth chamber after eight weeks from sowing and then chilling stress was imposed. After 12 hours of stress, aerial dry weight, SPAD value, chlorophyll a, b and a+b, carotenoid content and electrolyte leakage were measured. The data were analyzed using SAS statistical software and significant differences between means were estimated using least significant difference (LSD) test at P<0.05 of probability level. Results and discussion Results showed that chilling stress particularly for six days decreased aerial dry weight, chlorophyll a and b and carotenoid content (nearly 19, 18 and 8%, respectively) as compared to the uninoculated control. In all levels of chilling stress, however, P. indica inoculation increased plant dry weight in which the most beneficial effect (up to 65%) was recorded in severe stress. Mean comparison of three factors indicated that at all levels of chilling stress and PBZ, P. indica increased leaf and whole plant dry weight at the range of eight to 280% and 0 to 143%, respectively. The maximum increase for leaf dry weight (2.68 g/plant) was recorded where inoculated plants grown in normal conditions in no applied PBZ. Furthermore, the highest value of aerial dry weight (3.42 g/plant) recorded in plants which inoculated both with P. indica and sprayed with 80 mg/L of PBZ under normal conditions. PBZ spraying at the rate of 40 mg/L increased chlorophyll a, carotenoid and SPAD value by 5, 9 and 7%, respectively. In inoculated plants, however, PBZ spraying decreased plant dry weight particularly at the rate of 40 mg/L (nearly 17%). PBZ spraying, also, reduced electrolyte leakage in which the maximum reduction (up to 20% lower than non-application) was obtained with 80 mg/L of PBZ. Conclusion In conclusion, the results indicated that P. indica inoculation along with Paclobutrazol spraying had a positive effect on chilling tolerance in green beans. Therefore, these factors can be used to induce chilling stress tolerance. However, further tests should also be applied to other growth stages of plant.
Mehdi Jalilian; Massoud Dehdari; Reza Amiri Fahliani; Mohsen Movahedi Dehnovi
Abstract
Introduction Low temperature stress is one of the important abiotic limiting factors for plants growth, production and distribution. Low temperature also reducing plants biological activity and their economical yield. In spite farmers are regulated planting data of sugar beet to reduce plants damage ...
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Introduction Low temperature stress is one of the important abiotic limiting factors for plants growth, production and distribution. Low temperature also reducing plants biological activity and their economical yield. In spite farmers are regulated planting data of sugar beet to reduce plants damage from cold and frozen stresses in moderate and cold regions but, there are several reports which show root and sugar yield reducing due to cold stress especially at the early growth stages. This study aimed to investigate the effect of low temperatures on the morpo-physiological traits of sugar beet varieties at seedling stage, and to introduce cold tolerant genotypes and effective cold tolerance related characters of sugar beet plants. Material and method In order to study of cold tolerance of number of sugar beet cultivars, an experiment was conducted at Agriculture Faculty of University Yasouj in 2013-2014. Seedling of ten sugar beet cultivars {(Karaji, SBSI- 005, Shirin, Rastad, Zarghan, Persia (Iranian cultivars) and Anaconda, Dorothy, Merak, Antic (exotic cultivars)} at stage of 2 to 3 leaves (25 days after planting) exposed to four levels of temperature including: 0, 5, 10 and 25º C (as a control). The experiment for each temperature level was completely randomized design with three replications. In order to application of cold stress the pots were placed in a growth chamber at the above mentioned temperatures. Physiological and morphological traits of seedling plants including: shoot height, shoot and root dry weight, electrolyte leakage, proline content, SPAD number, total soluble sugars content and chlorophyll fluorescence were measured. Stress tolerance index (STI) calculated based on shoot and root dry matter. Combined analysis of variance was done and means of main (temperature and cultivar) and interaction effects were compared using LSD and LSmeans methods, respectively. Descriptive statistics, genetic and phenotypic coefficients of variation and broad sense heritability were calculated. Stress intensity for all the above mentioned traits was calculated and the most affected traits by cold stress determined based on its value. Data were subjected to factor analysis using principal component method and the most important factors were interpreted. Four factor scores were calculated and cultivar classification was done using three-dimensional scatter plot based on scores of the first three factors. Results and discussion Results of combined analysis showed that the effects of temperature, cultivar and their interaction were significant for the all measured traits. There was high diversity among the studied sugar beet cultivars for cold stress tolerance. Based on the results, cultivars showed different responses to temperature levels. The means of shoot (68%) and root (77%) dry matter reduced in stress condition (0˚C) than control condition (25˚C) but, the means of electrolyte leakage, proline content, total soluble sugars content increased 25, 90.5 and 71% respectively, in cold stress condition (0˚C) than control condition (25˚C). The highest genotypic correlation was observed between shoot height and total soluble sugars (-0.67) in non-stress (25˚C) and between root fresh weight and shoot dry weight (-0.43) in cold stress (0˚C) conditions. Leaf proline content had the highest (0.9) stress intensity indicating that it was most affected by cold stress. Shoot height had the highest (75.09%) broad sense heritability so; this trait can be transmitted to next generation. Factor analysis identified 4 factors in the cold stress (0˚C) condition that justified 71.7 percent of total variation. The first three factors were related to cold stress tolerance. Genotypes grouping using three-dimensional plot based on the first three factor scores, introduced Merak and Antic cultivars as cold tolerant, Drothy and Anaconda cultivars as semi-cold tolerant and other cultivars as cold sensitive. Conclusion In general, results of this investigation showed that there is enough genetic diversity of cold tolerance in sugar beet cultivars at seedling growing stage. In this study proline content, Fv/Fm ratio and root dry matter played key role in genotypes grouping based on their response to cold stress. The tolerant cultivars had high amounts of these traits than other cultivars. The results of this investigation can be used in sugar beet breeding programs to improve cold tolerance at seedling growth stage.
Volume 10, Issue 3 , October 2017, Pages 490-490
