جستجوی مقالات مرتبط با کلیدواژه « relative water content » در نشریات گروه « اکولوژی »

Intercropping reduces the application of chemical pesticides to control pests and weeds, reducing the environmental risks associated with chemical pesticide application (Himmelstein et al., 2017). Biochar is a soil amendment because of its potential to retain water and nutrients, prevent nitrogen leaching, increase soil fertility, and improve plant growth (Fang et al., 2018; Munoz et al., 2016). Other benefits of vermicompost are increased stability of soil resources, maintenance of production, reduction of environmental pollution, and increased soil biological activity too (Demir, 2019). Therefore, the purpose of this study was to investigate the quality of forage turnip (Brassica rapa var. rapa) leaves in different intercropping ratios of forage turnip and basil (Ocimum basilicum) using biochar as soil amendment and vermicompost.

A biennial study was conducted on the quality performance of forage turnip (Brassica rapa var. Rapa) in the form of split-plot factorial in a randomized complete block design with three replications in the research farm of Islamic Azad University of Karaj in two years (2018-2019). The treatments of this study include: intercropping in four ratio (100% forage turnip (monoculture), 90% forage turnip + 10% basil, 80% forage turnip + 20% basil, 70% forage turnip + 30% basil), in main plots, and vermicompost in two levels (15, 18.5 ton.ha-1) and biochar in two levels (No consumption and 5 ton.ha-1) which was placed in subplots. The forage turnip cultivar was PacFB05. In this study, Photosynthetic pigments were measured by the Arnon  (1967) method, membrane permeability (Ferrat and Loval, 1999), relative moisture content (Bertin et al., 1996), soluble leaf sugars (Sheligl, 1986), catalase (Dazy et al., 2008) and soil respiration (Isermeyer, 1952). Using SAS software (Ver.9) for data analysis of a two-year experiment and analysis of means was done with Duncan’s test in significance at 5% probability level. Excel software was used to plot the graphs.

The results of this study indicated that by increasing the ratio of basil in intercropping, the quality traits of forage turnip leaves increased. Consumption of biochar and application of vermicompost at the level of 18.5 ton.ha-1 increased the quality of forage turnip leaves. The highest chlorophyll a ((17.52 mg.g-1Fw), chlorophyll b (8.76 mg.g-1Fw) total chlorophyll (26.38 mg.g-1Fw), carotenoids (6.91 mg.g-1Fw), relative water content (59.54%), of soluble sugars (69.43%), catalase (0.018 micromole Fresh weight/min) were due to the interaction of (70% forage turnip + 30% basil) × vermicompost 18.5 ton ha-1 × application of biochar. The highest value of membrane stability index was related to 100% forage turnip × vermicompost 15 ton ha-1 (4.85 (mol.ml-1.s-1)). The highest amount of soil respiration is associated with the interaction of vermicompost 18.5 ton.ha-1 × 70% forage turnip + 30% basil with value of 0.28 (micromole.gsoil-1.hour-1)), interaction of biochar ×70% forage turnip + 30% basil (0.32 (micromole.gsoil-1.hour-1)), and interaction of vermicompost of 18.5 ton.ha-1 × biochar 0.31 (micromole. g soil-1.hour-1). Due to the potential of biochar (water and food retention and prevent of nitrogen leaching) it can increase the availability of water and nutrients for the plant, which leads to increased photosynthesis of the plant and thus the quality of forage turnip leaves (Akhtar et al., 2015; Hammer et al., 2015). Vermicompost increases soil organic matter and the uptake of zinc, copper, iron, phosphorus, potassium, and nitrogen in soil. The presence of these elements in the soil and their absorption by the roots increases vegetative growth and leaf production in the plant, which causes the level of light absorption, photosynthetic level, the formation of hydrocarbons in the leaves, and the resulting growth also increases leaf quality (Theunissen et al., 2010).

The results of this study indicated that the application of vermicompost ​​18.5 ton ha-1 and biochar increased forage turnip quality, which is due to the availability of water and nutrients for forage turnip. The best intercropping ratio was related to 70% forage turnip + 30% basil, which can be said to be due to the increase in the percentage of basil and the competition of plants for better use of intercropping components of growth sources such as light, water, and food.

Salinity stress is an important abiotic stress threatening the production of cotton in arid and semi-arid regions of the country and the world, which can be reduced by the proper use of organic materials. Cotton is the most important fiber product, which is widely cultivated for agricultural and industrial purposes in temperate and hot regions of more than 15 countries of the world. Although cotton is known as a salinity-tolerant plant, not only is the resistance to salinity limited in this plant, but different stages of development also show different reactions to salinity. One of the effects of stress is disturbing the nutritional balance in the plant. Proper nutrition during times of stress can partially help the plant deal with various environmental stresses. In this regard, by using fertilizers containing micronutrient elements, firstly, plant yield increases, secondly, increasing the concentration of these elements in agricultural products plays an important role in improving the quality of food consumption. Using organic fertilizers, especially organic and animal manure such as humic acid, can improve the performance and performance components of different products under stress conditions.

To study the effect of manure and humic acid on some of the physiological qualities of cotton under salt water salinity stress, an experiment was conducted as factorial split plots (factorial split plot) in which different levels of irrigation water salinity at three levels (2.5, 5.5 and 8.5 ds.m-1) as the main factor and two treatments of manure at two levels (0 and 20 t/h) and humic acid at two levels (0 and 200 gr/100 kg of seeds) as sub-factor in 4 replications in a farm located in Boshrouyeh city in 1398 years. The software SAS (V9.1) and Excel were used to analyze the data and draw the figures. Means were compared using the FLSD test at a 5% probability level.

Analysis of variance results showed that the simple effects of three experimental factors (salinity stress, manure, and humic acid) were significant on all studied traits (on the relative water content, Electrical conductivity and membrane stability, chlorophyll a and b contents, and proline content). With increasing salinity level, increased proline content (286.5%), membrane Electrical conductivity (4.2%) and carotenoids (88.79%) and decreased chlorophyll a (20.7 1 %) and b content (39.38%), relative water content (23.16%) and membrane stability (13.54%). The application of animal manure and humic acid increased the relative water content, membrane stability and chlorophyll content under stress conditions, which indicates the modifying effect of these fertilizers in reducing the adverse effects of salinity stress. The interaction effects were significant, too.

The results of this research showed that the use of water with high salinity, such as salinity of 8 ds.m-1, caused significant changes in the physiological traits of the plant, including relative leaf water content, membrane stability, membrane electrolyte leakage, chlorophylls, and proline. With increasing salinity levels, the amount of proline, membrane electrolyte leakage, and carotenoid increased, and the content of chlorophyll a and b, relative water content, and membrane stability decreased. The application of animal manure and humic acid increased the relative water content, membrane stability, and chlorophyll content under stress conditions, which indicates the moderating effect of these fertilizers in reducing the adverse effects of salinity stress. Considering the positive effects of using organic fertilizers in this experiment, it is recommended to test and investigate the use of humic acid during the growing season in addition to the use of animal manure before planting and the use of humic acid in bulk Thus, it is suggested to use humic acid and animal manure in cotton cultivation to adjust the salinity levels.

The aim of this study was to investigate the effect of biochar produced from wastes from pruning of pomegranate trees and compare it with vermicompost Oenothera biennis under drought stress.

Treatments included different levels of organic modifier application (seven levels including no modifier application, application of 10, 20 and 30 ton ha-1 vermicompost and application of 10, 20 and 30 ton ha-1 biochar) and three levels of drought stress (irrigation in 80, 60 and 40% of field capacity (FC)).

The results showed that drought stress significantly decreased leaf length, leaf area, stem diameter, plant height, chlorophyll index and relative water content (RWC) while increased the ratio of root dry weight to shoot and ion leakage. Application of 30 ton ha-1 biochar and all application levels of vermicompost decreased root dry weight to shoot ratio under severe drought stress. All application levels of vermicompost were increased the chlorophyll index under severe stress while different levels of biochar had not significant effect. All amendments significantly increased RWC compared to the control under moderate and severe stress conditions. Application of 30 ton ha-1 biochar and vermicompost decreased ion leakage compared to the control.

It seems that organic amendments can help the plant in stressful conditions by affecting the availability of nutrients and increasing the soil moisture holding capacity. In this study the effectiveness of vermicompost was better compared to biochar, which can be attributed to the higher content of nutrients in vermicompost.

The appropriate amount of nitrogen consumption and the positive effects of wheat straw mulch in medicinal plants are important to reduce the negative effects of drought stress and achieve high yield.

In this study, the growth and yield of black seed by combining nitrogen and wheat straw mulch at different irrigation intervals. This research was conducted as a split plot in a randomized complete block design. The first factor is different irrigation intervals in three levels including 25, 50 and 75% moisture drainage and the second factor in six levels includes 50 and 100 kg of urea per hectare in combination with mulch and consumption alone, mulch and control.

Increasing irrigation intervals decreased the amount of leaf elements. Also, an increase in ion leakage and decrease in the relative leaf water content were observed in 75% of moisture depletion. Application of wheat straw mulch was able to reduce ion leakage of black seed under drought stress conditions. Urea was effective in increasing nitrogen uptake and as a result increased the amount of photosynthetic pigments. At 25% moisture discharge, shoot dry weight per 100 kg of urea with wheat mulch and consumption alone showed an increase of 8.7% and 7.1%, respectively, compared to the control. The highest harvest index and yield components were observed in the use of mulch in combination with urea.

In total, the application of 100 kg of urea per hectare in combination with wheat straw mulch for planting black seed is recommended.

Following climate change, drought stress has become the most important limiting factor for crop production and. Plants become under dry when the water available to the roots is limited or the water loss through transpiration is very high. Decreased photosynthetic active radiation absorption, impaired light consumption efficiency and reduced harvest index are the most important factors reducing yield in soil moisture deficit conditions. On the other hand, the adverse effects of the use of chemical drugs in recent years have led to much attention to the cultivation of medicinal plants, which with the increase in their use requires the development of cultivation, management and proper planning. Bio-fertilizers as an alternative in some cases and in most cases as a complement to chemical fertilizers can help to ensure the sustainability of agricultural production systems.

 The study was aimed to evaluate the effect of nitroxin biological fertilizer on ecotypes of black cumin under drought stress. The experiment was conducted as a split-split plot with three replicates at Ilam University during growing season of in 2018. Drought stress levels including no stress (Irrigation based on 100% of plant water needs), moderate stress (Irrigation based on 50% of plant water needs) and severe stress (Irrigation based on 35% of plant water needs) as main plot, nitroxin fertilizer treatments including no nitroxin (control) and application of 1 liter ha-1 nitroxin as sub plot and ecotype treatments including Neyshabour, Mashhad, Semirom and Isfahan Sub-plots were considered as sub-plots. Measured traits included plant height, number of sub-branches, yield, grain yield components (number of follicle and number of seeds per follicle), relative leaf water content, ion leakage and photosynthetic pigments.

 The results showed that the main effect of drought stress, nitroxin and ecotype on all treats were significant (p≤0/01). The highest plant height and the first sub-branch height of Mashhad ecotype were obtained under Irrigation based on 100% of plant water needs conditions under moderate stress. The highest number of branches per-plant of Neyshabur ecotype was obtained under nitroxin under drought stress conditions. The highest number of capsules per plant was obtained from Mashhad ecotype treatment with no nitroxin and Irrigation based on 100% of plant water needs. The highest number of seeds in main capsule, seed yield and harvest index were obtained from Semirom ecotype under nitroxin under Irrigation based on 50% of plant water needs. The highest biological yield was obtained in Isfahan ecotype, nitroxin consumption and Irrigation based on 50% of plant water needs.The results of this study showed that drought stress caused a significant reduction (p≤0.01) in the values of chlorophyll a, b and total chlorophyll traits and relative moisture content of leaves Meanwhile, the use of nitroxin biological fertilizer in most cases improved these traits in different ecotypes, which can be due to the positive effects of biological fertilizer in helping to better absorb water and nutrients under drought stress and reduce the negative effects of water deficiency on Physiological traits of the plant.

 Since better absorption of nutrients depends on the existence of an extensive root system, it seems that the lack of expansion of the plant root system under drought stress and the lack of use of chemical fertilizers, the ground for the activity of microorganisms. This has led to the improvement of the root system and consequently better absorption of water and nutrients needed by the plant in conditions of moisture stress. In general, the results of this study indicate that the application of biological fertilizers may have had a positive effect on improving the yield and quantitative properties of the herbicide under drought stress conditions, however, this issue needs further investigation. From the results it can be concluded that moderate drought stress can be applied in weather conditions Ilam province in addition to reducing water consumption will lead to better outcomes.

In order to consider some echo-physiological responses related to the productivity of safflower fall genotypes to drought stress at plant greening, establishment, and seed filling stages and to recognize drought-tolerant genotypes, the present study was done.

An experiment was conducted as a split-plot based on a randomized complete blocks design with three replications in the Khosrow Shah station of East Azarbaijan Agriculture and Natural Resources Research and Education Center during the 2019-20 cropping season. The experimental factors included drought stress (non-stressed and stressed during plant greening and the establishment and seed filling stages, and five safflower genotypes including Padideh, Golemehr, Parnian, Mexico248, and Mexico14.

Occurring drought stress at the seed filling stage significantly decreased chlorophyll concentration, stomatal conductance, relative water content, seed and oil yields, and seed yield components in fall genotypes of safflower. Correlation among mentioned indices echo-physiological indices with each other and with seed and oil yields were positive and significant. Also, the amounts of mentioned indices among studied genotypes were significantly different.

The seed filling period of fall genotypes of safflower was critical for water requirements. Chlorophyll concentration, stomatal conductance, relative water content indices were able to reflect the drought stress effect during the seed filling period and can recognize the fall genotypes of safflower with high seed and oil yields under drought conditions. It seems that these echo-physiological indices are suitable to select late-season drought-tolerant safflower genotypes.

Quinoa (Chenopodium quinoa Willd.) is an herbaceous spring-annual plant and a pseudocereal, belonging to the Chenopodiaceae, and have high nutritional value. Studies have shown that the use of organic fertilizers such as vermicompost can reduce the negative effects of salinity stress on plants and improve their growth and yield. 

This experiment was conducted in a completely randomized design with factorial arrangement with three replications in a sterile sandy loam soil under greenhouse conditions. Experimental factors included vermicompost levels of 0 and 2%, and sodium chloride salinity levels of 1.06 (soil initial electrical conductivity), 5, 10, 20 and 30 dS.m-1.

The results showed that the interaction between salinity and vermicompost was significant (p≤0.05) on all measured traits. The fresh and dry weight of roots decreased in the presence and absence of vermicompost with increasing salinity. At different salinity levels (except for 30 dS.m-1), vermicompost treatment increased roots fresh and dry weight. The negative effect of salinity on fresh and dry weight of shoots was less than roots and a significant decrease occurred at 30 dS.m-1. Chlorophyll index decreased with increasing salinity but it increased significantly at all salinity levels in vermicompost treated plants. Vermicompost treatment showed a positive effect on stomatal conductance at salinity levels of ≤10 dS.m-1. Electrolytes leakage decreased in vermicompost treated plants at salinity levels of ≤10 dS.m-1.

The vermicompost application had a positive effect on the biomass production, growth status and yield of quinoa under salinity stress.

The pear is one of the most important fruit trees in temperate regions and is salt-sensitive trees. Studies have shown that the use of Piriformospora indica as an endophytic fungus reduces the adverse effects of salinity stress on plants and improves morphophysiological traits.

In the present study, the experiment was performed as a factorial completely randomized design with 5 replications on the pyrus rootstock CV Pyrodvarf in pot culture experiment. The first factor includes two levels of P. indica fungus (inoculation and non-inoculation) and the second factor is four salinity levels of soil (1.7, 3, 4.5 and 6 dS.m-1) using sodium chloride. After inoculation with the fungus, the salinity levels were applied to the plants.

The results showed that the interaction effect of salinity × fungi on morphophysiological characteristics, total chlorophyll content (P <0.05), branch diameter growth, electrolyte leakage, proline, soluble sugars, peroxidase and polyphenol oxidase enzymes and root colonization percentage (P <0.01) were significant. At the highest salinity levels (6 dS/m), fungal inoculation caused an increase in surface-to-root dry weight ratio (38.81%), branch diameter growth (31.14%), total chlorophyll (27.72%), peroxidase (100%), polyphenol oxidase (62.5%) and root colonization percentage (100%) and decrease in electrolyte leakage rate (19.34%), proline (10.34%) and soluble sugars (8.77%) ) compared to non-inoculated control plants.

In general, the results of this study showed that the coexistence of P. indica can modulate the destructive effects of salinity on this pear cultivar.

The goals of study were to recognize the effects of water deficit on eco-physiological and agronomic responses of safflower and introducing drought tolerant genotypes to cultivate in saline and dry lands.

The experiment was conducted as split plot based on randomized complete blocks design with three replications in the East Azarbaijan Agriculture and Natural Resources Research and Education Center during two cropping seasons (2017-19). The experimental factors included drought stress as non-stressed and stressed from flowering to maturity and six safflower genotypes including Padideh, Golemehr, Mexico14, Mexico248, Mexico295 and Parnian.

Seed and oil yields and yield components of genotypes decreased by drought. Water deficit stress decreased RWC, stomatal conductance and leaf chlorophyll index significantly. Amounts of these characters were significantly different among genotypes. Correlations among studied traits were significant. Stomatal conductance and RWC indicated significant correlations with capitulum number per plant and oil percent. Also RWC indicated significant correlation with seed yield. Correlations among capitulum number per plant and grain number per capitulum with each other and seed oil percent, seed and oil yields, were positive and significant. These yield components had important role in productivity.

stomatal conductance and RWC are able to reflect the effects of late season drought stress on safflower and can be used to select drought-tolerant genotypes. Golemehr, Mexico14, Mexico248 and Mexico295 genotypes indicated higher seed and oil yields in both normal and drought conditions and were seen suitable to cultivate in saline areas around Ormieh lake and areas with similar climate.

In order to study the effects of salicylic acid (SA) and megafol (MF), on pod and seed yield and quality of common bean cv. Sanry under water deficit stress, the field experiment was conducted in split plot based on randomized complete block design with three replications. Three different irrigation regimes (33, 66 and 100% ETc) and foliar application of SA (0.5, 1 and 1.5 mM) and megafol (0, 0.1, 0.2 and 0.3 percent) were conducted. The results showed that water deficit stress significantly reduced pod lengh, pod fresh weight, seed number per pod, pod and seed yield, leaf relative water content and nitogen, phosphor and potassium contents. Water deficit stress reduced pod yield of 67.6% in 75% ETc and 94% in 50% ETc. Foliar application of SA and MF improved yield and quality of seed and pod, leaf relative water content and nutrient contents. The highest pod yield (13625.3 kg.ha-1), number of pods per plant (7.69), seed yield (4303.87 kg.ha-1), protein yield (671.8 kg.ha-1), carbohydrate yield (3356.7 kg.ha-1) was obtained with application of MF 0.2% under irrigation 100% ETc. The maximum value of carbohydrates (55.9 and 55.25%) was observed with application of MF 0.2% under irrigation 75 and 50% ETc, respectively. According to the results, the application of SA 1.5 mM and MF 0.2% can be proposed to improve yield and quality of pod under normal irrigation and water deficit stress.

Nowadays, the development of green space with ornamental species of cypress is a common in different dry areas of Iran. Regarding the limitation of water resources in dry areas, study on the response of cypresses to drought is essential. This study was carried out to recognize the responses of survival, growth, gas exchange and water relations in seedlings of two cypress species (Cupressus arizonica and C. sempervirens var. fastigiata) under water deficit condition in greenhouse. The experiment was conducted as complete randomized block design with different watering levels (3, 6 and 9 days) in three replicates. Results showed that water deficit had a significant effect on most of the traits measured in seedlings. Survival of C. sempervirens at 9-day irrigation was decreased about 50.2% but in C. arizonica seedling no mortality was detected in each watering level. During drought application, shoot growth and diameter growth in both species prominently decreased, while at 6- and 9-day irrigation, shoot growth in C. arizonica was 43-47% greater than that in C. sempervirens. With increasing drought, photosynthesis activity, stomotal conductance and water potential decreased but intracellular CO2 concentration (Ci) and leaf temperature did not change. Transpiration rate and relative water content (RWC) of leaf were significantly decreased in both species, but in C. arizonica the decrease of transpiration rate at 6- and 9-day irrigation was 12-32/3% less than that in C. sempervirens. Generally, it can be stated that C. arizonica seedling is more tolerant than C. sempervirens seedling under drought stress.

IntroductionOilseed rape (Brassica spp L.) is one of the valuable oilseed crops which has been attracting attention in recent years. Iran is located in a semi-arid region, and water shortage has caused problems, namely providing drinking water as much as water supply for crop production. Not only does Plant Growth Promoting Rhizobacteria (PGPR) make plant growth stimulating hormones like Auxin and Gibberellin but also can ease stress conditions by producing ABA. Consequently, considering the current water shortage crisis in Iran, we took three main criteria into account: the roles of PGPRs in increasing resistance to abiotic stress, relief of drought effects, and the importance of cultivation of oilseed rape. The present research has been compiled to study drought and some Plant Growth Promoting Rhizobacteria (PGPR) on Physiological Traits and Ultimate Yield of Cultivars of Oilseed Rape.
Materials and MethodsThe current study was done on the basis of two simultaneous experiments (under stress and non-stress experiments) during 2010- 2011 growing season at Agriculture and Natural Resources Research Station of Torogh, Mashhad is situated in East-North of Iran (36° N, 59° E, 1003 ASL ) . Two research sites (under stress and no-stress fields) were selected beside each other. This region has a semi-arid climate (annual rainfall 286 mm). The experimental design was factorial based on randomized completely block design with three replications in each experiment. The first treatment was Plant Growth Promoting Rizobactria, including B0: no inoculation (control), B1: co-inoculation (Pseudomonas flourescens 169. putida 108), B2: inoculation with P. flourescens 169 and B3: inoculation with P. putida 108. Second treatment was cultivar, including Hayola401 and Hayola330 cultivars belong to Brassica napus, Parkland and Goldrush cultivars belong to B. rapa and BP18 and landrace cultivars belong to B.juncea .Greenness index, plant height, relative water content, canopy temperature depletion , harvest index and final seed yield were measured in the present study as well. In addition, variance analysis (ANOVA) was performed using SAS ver. 9.1 software.
Result and DiscussionThe examination of physiological characteristics including Harvest Index (HI), chlorophyll content, and Relative Water Content (RWC) showed that there is a considerable difference between location, cultivar, and bacteria cultivar. At the second stage of sampling, due to the reduction of cell water content and enhancement of concentration of cell content in stress field, the chlorophyll rate was enhanced in stressed locations. While findings in RWC showed that Pseudomonas putida had the highest percentage (64.23%), and no inoculation had the lowest RWC (60.32%). Therefore, inoculation treatment, specifically the individual inoculation in the study of RWC, could ease the effects of drought stress. Results of the final stem height were significant, only in cultivar level and BP.18 with 1.24m was the highest and Hayol 330 with 0.9m was the shortest cultivars regarding to stem height. Individual and interaction effects of bacteria with other treatments on harvest index were significant. In current study, it seems that application of bacteria treatments has caused better formation of final seed yield .There was a considerable difference between location, cultivars and interaction of location×cultivar regarding to ultimate yield. Final seed yield in non-stress location (1351.85 Kg.ha-1) was significantly higher than in stress location (535.38 Kg.ha-1). In the study of both morphological and physiological traits and final seed yield of the current research, Hayola hybrid showed more superiority than other cultivars.
ConclusionIt seems the individual application of either P. flourescens 169 or P. putida 108 leads to better formation results than two mixed strains of the aforementioned bacteria. In the current study, Hayola hybrids showed a better function in physiology and ultimate yield; therefore, plantation of these hybrids would be valuable even in water deficits as well as application of PGPR.

Evaluation of drought effects on some physiological traits relevant to drought tolerance, seed and oil yields, yield components and recognizing tolerant oilseed rape genotypes were the goals of research. The experiment was conducted as split plot based on a randomized complete block design with three replications in East Azarbaijan Research and Education Center for Agriculture and Natural Resources during 2015.The experimental factors were drought stress with three levels: non-stressed and drought stress from flowering and pod formation stages and genotype in 5 levels: RGS003, Zafar, Sarigol, Zarfam and Dalgan. Occurring drought from flowering and pod formation stages led to significant increase in leaf temperature and significant decrease in leaf relative water content, stomatal conductance, pods per plant, 1000 seeds weight, seed and oil yields. But the effects of drought from flowering stage were too hard. In case of water resources limitation, irrigation during flowering stage will be more important than pod formation stage. The existence of significantly negative correlation among leaf temperatures and significantly positive correlations among leaf relative water content, stomatal conductance with the pods per plant, 1000 seeds weight, seed and oil yields showed that, these traits can indicate drought effects on spring oilseed rape. Also the existence of significantly positive correlations among the pods per plant and 1000 seeds weight with seed and oil yields, showed that, drought reduced yields via decreasing these components. All of studied genotypes indicated similar performance under non-stressed condition. But under drought conditions, RGS003 indicated higher seed and oil yields.

To evaluate the response of wheat to drought stress and salicylic acid، this field experiment was carried out at the Experimental Farm of College of Agriculture، University of Shahid Bahonar Kerman، Iran in 2011-2012، in a split-plot arrangement using completely randomized block design with four replications. Main plot was irrigation (normal irrigation and cut off at flowering) and sub plot was salicylic acid (0، 0. 1 and 0. 5 mM). The results of analysis of variance showed that drought stress significantly reduced relative water content (35%)، fertile spikes per m-2 (10%)، grain per spike (25%)، 1000 grain weight (30%)، grain yield (65%) and biological yield (40%). Results also showed that drought stress increased electrolyte leakage (55%) as well as proline of flag leaf (60%). In contrast، salicylic acid significantly increased relative water content، grain yield، biological yield as well as proline of flag leaf and also reduced electrolyte leakage. However، the effect of 0. 5 mM was more pronounced. Therefore، it is concluded that seed treatment with salicylic acid may promote resistance of wheat under drought conditions via maintaining cellular membrane integrity and increasing proline concentration.

Two field experiments were conducted at the Research Farm of the Faculty of Agriculture، University of Tabriz، Iran during 2009-2010 and 2010-2011، to evaluate the response of fennel (Foeniculum vulgare L.) landraces to limited irrigation. Experiments were arranged as split plot based on randomized complete block design in three replications with irrigation treatments (Irrigation after 60، 90، 120 and 150 mm evaporation from class A pan) in main plots and landraces (Hamdan، Ezmir and Gaziantep) in subplots. Chlorophyll a، Chlorophyll b and Proline contents، soluble carbohydrates، relative water content and leaf water potential of fennel were recorded at flowering stage. The results showed that the all traits of fennel were significantly affected by limited irrigation. Chlorophyll a، chlorophyll b، relative water content and leaf water potential decreased by 30، 24، 27 and 41%، but proline and soluble carbohydrate increased by 41 and 23%، respectively، due to water deficit. Ezmir and Hamdan were more drought tolerant than Gaziantep land race. Therefore، fennel plant uses osmoregulation by increasing proline and soluble carbohydrate in order to tolerate water limitation.