Use of biochemical indices and antioxidant enzymes as a screening technique for drought tolerance in Chickpea genotypes (Cicer arietinum L.)

In order to evaluate the physiological and biochemical traits regarding drought tolerance and further to determine the best criteria for screening and identification of drought tolerant chickpea genotypes, an experiment was conducted in controlled conditions in the Plant Science Research Center of Ferdowsi University of Mashhad in Iran. In this study, two tolerant genotypes (MCC392 and MCC877) and two susceptible genotypes (MCC68 and MCC448) were grown under controlled (field capacity) and drought stress (25% field capacity) conditions. In this experiment, tolerant and susceptible genotypes were compared with each other for proline, malondialdehyde and soluble protein content. We also compared these genotypes with each other for catalase, ascorbat peroxidase, peroxidase and superoxide dismutase during the stages of seedling, flowering and podding. The results showed that drought stress significantly increased proline content in the flowering and podding stages and also increased catalase activity in the three investigated stages. By contrast, the effects of drought stress on ascorbat peroxidase, peroxidase and malondialdehyde were not significant. In the flowering stage, tolerant genotype (MCC877) had higher catalase activity as well as, higher proline contents in comparison with susceptible genotypes (MCC68 and MCC448). Also, drought stress had significant effects on superoxide dismutase activity in the flowering stage. These results indicated that catalase and superoxide dismutase activity and proline content can be effective markers in the identification of drought tolerant chickpea genotypes. Also, the flowering and podding stages can be more suitable than seedling stage for comparing susceptible and tolerant genotypes under drought stress and also to classify adapted cultivars of chickpea under drought stress.   Key words: Antioxidant enzymes, Chickpea (Cicer arietinum L.), drought, malondialdehyde, proline.