Genetic variation in drought tolerance in chickpea (Cicer arietinum L.) genotypes

Drought is one on the most important factors limiting the productivity of spring chickpea in drylands of Iran. Sixty genotypes of chickpea from ICARDA's germplasm accessions, as well as one drought susceptible check (ILC 3279), were sown in spring of 2010 at two locations, Sanandaj and Maragheh, in the western highlands of Iran for one year. The experiment in each location was laid out in a randomized complete block design with two replications. The results of the analysis of variance for seed yield, 100-seed weight, pods per plant, plant height and days to maturity indicated that genotypic differences were significant. Seed yield ranged from 266 kg/ha (FLIP06-58C) to 1020 kg/ha (FLIP 06-60C). The phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) and the environmental coefficient of variation (ECV) for all traits. The PCV was highest for drought tolerance score (44.54%), followed by plant vigor (32.24%), seed yield (28.47%) and pods per plant (27.59%). Similarly, the GCV was highest for drought tolerance (39.27%), followed by plant vigor, seed yield and pods per plant. The GCV and PCV were lowest for days to maturity, followed by days to flowering and 100-seed weight. Heritability of days to maturity, days to flowering and drought tolerance was greater than the heritability of the other traits. Positive significant (P < 0.05) relationships were found between seed yield per plant and traits pods per plant, 100-seed weight and plant height. The genotypic path coefficient analysis based on seed yield per plant as a dependent variable revealed that drought tolerance score, 100-seed weight, plant height and pods per plant exhibited high positive direct effects. Vigor, days to maturity and 100-seed weight showed the highest direct influence. Therefore, this research suggests that drought tolerance score and pod per plant can be good selection criteria for improving seed yield per plant in chickpea for drought stress environments.