ارزیابی شاخص‌های تنش برای گزینش تحمل به خشکی در نخود (Cicer arietinum L.)

In order to evaluate drought tolerance indices in chickpea, determination of the best indicator of drought tolerance and identifying tolerant cultivars in water limited condition, a randomized complete block design (RCBD) with three replications and 20 chickpea genotypes was used under irrigation and rainfed conditions at research farm of College of Agriculture, Razi University, Kermanshah. The results of correlation coefficient showed that STI and GMP indices are advisable for selection of higher yielding chickpea cultivars in water limited condition while in situations in which water supply is not critical MP index can be used. The results of stepwise regression showed that HM (R2= 0.92) and MP (R2= 0.75) indices determined the most variation of the traits in rainfed and irrigated condition, respectively. Based on evaluation of drought tolerance indices, the cultivars Bivanich, Flip-82-115, X95TH42 and X95TH54 were identified as tolerant chickpea cultivars in water limited condition. The results of dendrogram for cultivars based on HM, STI, GMP and MP was in agreement with three dimensional plots of these indices. Cluster analysis of cultivars based on evaluated indices showed that the cultivar X95TH42 was classified in a separated group while S95274, Flip-82-242, S96085, Flip-99-26c, IIC482, Flip-82-115, X95TH69, X96TH54 and Bivanich were belonged to the second group of cluster tree. Therefore, according to yield differences between cultivars, it seems that crosses between cultivars in second and third groups would enhance genetic variation in chickpea breeding programs. In general, the results of this study revealed that GMP and MP indices were more efficient to select drought tolerant chickpea cultivars and consequently the cultivars Bivanich, Flip-82-115, X96TH54 and X95TH42 could be considered as tolerate cultivars. In addition, due to low TOL for X95TH42 compared to other cultivars, it can be concluded that it has highest tolerance to drought condition among evaluated chickpea cultivars.