Effects of drought stress gradient on agronomic traits in Kabuli chickpea core collection

Drought stress is the most important limiting facor in rainfed agriculture all over the world. Generally, in the west Asia region, chickpea is cultivated as a rainfed crop, and its pod- filling phase often sufferes from late season drought which significantly reduces seed yield. To study the genetic variation and to determine the relationship between seed yield and some agro- morphological traits, the reaction of 103 accessions of Kabuli chickpea core collection of Natioanl Plant Gene Banak plus three improved cultivars (Jam, Arman and Hashem) was evaluated under four moisture conditions: normal (T1), low (T2), medium (T3) and limited (T4), using line source irrigation system. Experiment was conducted in Karaj Research Field Station Seed and Plant Improvement Institute, Karaj, Iran in 2006-07 cropping season. Different agro- morphological traits have been measured and recorded. Descriptive statistics nalysis revealed that there were significant variation in number of sub- branches, plant dry weight, number of seed per plant, harvest index, 100 seed weight and seed yield. Seed weight per plant had the most coefficience of variation. Variation in stress tolerance and susceptibility indices suggested a high genetic variation in studied Kabuli chieckpea genotypes. The correlation between seed yield, in stressed and non-stress conditions, and different drought tolerance indices indicated that STI and GMP were the more suitable indices for screening of Kabuli Chickpea genotypes for drought tolerance. Comparison of three dimension plot and bi-plot showed that in T3 condition, genotypes no. 67, 68 and 74 and in T4 conditions, genotypes no. 45, 47,105 and 110 were of higher drought tolerance.