فهرست مطالب سید محمد ناصح حسینی

Chickpea (Cicer arietinum L.) is the third most important grain legume in the world and the second grain legume in the Mediterranean environment including Iran. Average of chickpea grain yield in Iran is about 500 Kg ha−1 while in the world this average is 900 Kg ha−1.These data indicate the importance of research on chickpea. Water deficit stress is one of the most important factors in reducing grain yield of chickpea in the Mediterranean region. In such areas, water shortage almost take place at flowering and post flowering period. Generally, water deficit stress with decreasing plant photosynthesis and consequently reducing the production of photosynthetic products, the process of plant growth and development caused reduction of plants economic grain yield. In chickpea, flowering and podding stages are the most sensitive growth stages to water deficit and water shortages in these stages result in a significant reduction in grain yield. Hence, the present study was conducted to investigate the resistance of commonly chickpea cultivars used under cultivation in Kermanshah region in different water deficit stress conditions from the beginning of flowering and podding until maturity time.

In order to investigate the effect of post anthesis water deficit on yield and its components in different chickpea cultivars, a split-plot experiment based on complete block design with three replication conducted in research filed and labs of agronomy and plant breeding department of Razi university. The main factor was the moisture regime with three levels included: 1) control, 2) Irrigation cut from flowering till maturity and 3) irrigation cut from podding till maturity. Sub-factor consisted of different chickpea cultivars (Arman, Azad, Bivanij, Hashem and ILC482). Sowing was done manually. Each plot was consisted of six rows with three meters in length and with a spacing of 25 cm and 10 cm seeds space on the row. Harvesting was performed when each cultivar were matured under control and water deficit treatments and different traits was evaluated. These traits consist of: grain yield, biomass, straw yield, harvest index, number of pod per plant, number seed per pod, number of seed per plant, and 100 grain weight. Correlation coefficients between different traits under different water regime were estimated. The obtained data were exposed to analysis of variance (ANOVA). Means comparison was done using Duncan's new multiple range test (DMRT) using MSTAT-C software. Correlation coefficients between traits were estimated with SAS software ver. 8.0 (SAS Institute Inc., Cary, NC, USA).

 According to the results, water deficit at both levels, significantly reduced the grain yield, biomass, harvest index, 100 seed weight, number of seeds per plant and pod and number of pods per plant. The highest reduction in grain yield and biomass under water deficit from beginning of flowering till maturity was observed with about 51 and 36 percent, respectively. Under control condition, the highest grain and biological yield in Arman cultivar was 1355 and 3126 Kg ha-1, respectively. In application of water deficit from the beginning of podding until maturity, the highest grain and biological yield in Azad and Bivanij cultivars was 1035 and 2570 Kg ha-1, respectively and under water deficit stress from the beginning of flowering until maturity the highest grain and biological yield in ILC482 cultivar was 715 and 2000 Kg ha-1, respectively. Also, according to the results of correlation analysis, there was a positive and significant correlation between grain yield and biological yield, harvest index, number of pods per plant and number of seeds per plant. Azad, Bivanij and ILC482 cultivars showed better performance at both levels of moisture stress. Regarding the occurrence of moisture stress in the studied area at flowering and podding time in spring planting, spring cultivation of these cultivars is more desirable.

The results of this study showed that Azad, Bivanij and ILC482 cultivars were resistant to drought stress and their yield reduction was less than Arman and Hashem cultivars, also it is recommended that the Hashem cultivar dose not cultivate in spring at Kermanshah region. Generally, more resistant to drought varieties were more capable of water management which also improved the process of photosynthesis and helped to maintain better functionality in these conditions

To study the effect of water deficit on biochemical changes in chickpea, a split-plot experiment based on complete block design with three replications was carried out at the Research Farm of Razi University in Iran. Moisture regimes with three levels, were: 1) irrigation cut off from beginning of flowering till maturity, 2) irrigation cut off from beginning of podding till maturity and 3) irrigating plants at all stages of growth (control) assigned to the main-plots and five chickpea cultivars: Arman, Azad, Bivanij, Hashem and ILC482 to the sub-plots. Based on the results, two levels of water deficit resulted in significant reduction in the chlorophylls and carotenoids concentration and significant increase in the activity of antioxidant enzymes such as: catalase, peroxidase and super oxide dismutase of leaves, in comparison with control. Therefore, there was a negative correlation between the activity of antioxidant enzymes and the amount of available water in soil, and their activity increased with increasing the severity of water stress. Seed yield was significantly affected by water deficit. In comparison of control treatment, irrigation cut off from the beginning of flowering up to maturity compared to irrigation cut off from podding up to maturity resulted in more reduction in seed yield (36 and 15% respectively). ILC482 cultivar with seed yield of 715 kg.ha-1 under irrigation cut off from the beginning of flowering up to maturity and Arman cultivar with a seed yield of 1355 kg.ha-1 under irrigation cut off from podding up to maturity produced highest grain yield. High yield cultivars under two levels of water deficit including: ILC482, Azad and Bivanij also had the highest photosynthetic pigments concentration and highest antioxidant activity in their leaves. The results also indicated a positive relationship between the antioxidant enzymes activities and photosynthetic pigment concentrations in chickpea which may help to increase growth and yield of chickpea under drought stress conditions.

In order to investigate the physiologic and biochemical changes of drought tension in chickpea, a split-plot experiment based on randomized complete blocks design with three replications at the research farm of Campus of Agriculture and Natural Resources of Razi University of Kermanshah was conducted. The main factor was the moisture regimes including: 1-normal irrigation, 2- water deficient tension at podding stage and 3- flowering and the sub factor, including: five chickpea cultivars (Arman, Azad, Bivanij, Hashem and ILC482). The obtained results indicated a high effect of the moisture content of chickpea, on grain yield and biological yield, and among cultivars under intense moisture tension , ILC482 cultivar with seed yield of 715 (kilogram per hectare) and in non-tension conditions , Arman cultivar with the yield of 1355 (kilogram per hectare) showed the best performance. Based on the results, the photochemical efficacy of the photo cysteine II and the relative water content of the leaf had a positive and significant relationship with the amount of water available and the moisture restriction reduced these significant traits and in resistant cultivars including Azad, ILC482 and bionic, higher values of these traits were observed during drought tension. The content of soluble sugars and proline in chickpea leaves increased with decreasing moisture content, so that the amount of soluble sugars in the ILC482 and Azad cultivars and the amount of proline in ILC482 and Bivanij cultivars were higher, but on the contrary, the concentration of soluble proteins increased with increasing moisture content and was the highest in Hashem and Arman cultivars.