EVALUATION OF DROUGHT TOLERANCE OF CHICKPEA (CICER ARIETINUM L.) LINES USING AGRO-PHYSIOLOGIC CHARACTERISTICS

To evaluate of the reactions of chickpea lines to drought stress during seed germination and later growth stages, 17 lines were studied under controlled conditions at four water potential levels and in field at optimum and water-limited conditions. Physiologic characteristics including leaf water potential ( Y w), leaf relative water loss (RWL), and chlorophyll content (Chl) at flowering and pod filling stages were measured. The results showed that with decrease of water potential (0 to -1.2 Mpa), all characteristics of germination were significantly decreased. The highest germination stress index (GSI) was related to the lines Bivanij and Flip < sub>95-48C. Positive and significant correlation was observed between maximum germination (Gmax) and GSI. In field, drought stress reduced Y w in the both growth stages. Significantly reduction for Chl was not observed. Based on stress tolerance index (STI), lines 18-59-15 and Flip < sub>97-188C were superior to the other lines. In pod filling stage, the highest Y w was related to these two lines as well as line 12-60-31 under stress condition. In flowering stage, Flip < sub>89-50C, and in pod filling stage two above mentioned lines with the highest STI, as well as lines Flip93-166C and Flip < sub>95-42C had the lowest RWL. In the both growth stages, and both conditions, the highest Chl belonged to Flip94-111C. Under water-limited condition, Y w had negative and significant correlation with RWL in the both growth stages. Based on the obtained results, drought tolerance was related to high leaf water contents. The results of stepwise regression showed that biological yield in optimum condition unfilled pod percent and grain weight in stress condition, as well as number of pods per plant had the highest effect on yield.