DROUGHT STRESS EFFECTS ON PHOTOSYNTHESIS, CHLOROPHYLL FLUORESCENCE AND WATER RELATIONS IN TOLERANT AND SUSCEPTIBLE CHICKPEA (CICER ARIETINUM L.) GENOTYPES

In order to evaluate morphological and physiological traits related to drought tolerance and to determine the best criteria for screening and identification of drought-tolerant genotypes, we grew two tolerant genotypes (MCC392, MCC877) and two sensitive genotypes (MCC68, MCC448) of chickpea under drought stress (25% field capacity) and control (100% field capacity) conditions and assessed the effect of drought stress on growth, water relations, photosynthesis, chlorophyll fluorescence and chlorophyll content in the seedling, early flowering and podding stages. Drought stress significantly decreased shoot dry weight, CO2 assimilation rate (A), transpiration rate (E), and PSII photochemical efficiency (F-v root F-m) in all genotypes: In the seedling and podding stages, PSII photochemical efficiency was higher in tolerant genotypes than in sensitive genotypes under drought stress. Water use efficiency (WUE) and CO2 assimilation rate were also higher in tolerant than in sensitive genotypes in all investigated stages under drought stress. Our results indicated that water use efficiency, A and F-v root F-m can be useful markers in studies of tolerance to drought stress and in screening adapted cultivars of chickpea under drought stress.