Exploration of biochemical and molecular diversity in chickpea seeds to categorize cold stress-tolerant and susceptible genotypes

Chickpea (Cicer arietinum L.) genotypes are sensitive to low temperature (< 10A degrees C) during its reproductive stage suffer from abortion of flowers, infertile pods and small shriveled seeds that resulted in a significant decrease in crop yield. In the present investigation seeds of a number of cold stress-tolerant and susceptible genotypes were evaluated for biochemical and molecular diversity with the purpose to categorize them. The activities of various antioxidative enzymes (superoxide dismutase, glutathione reductase, ascorbate peroxidase and catalase), content of H2O2 and malondialdehyde, enzymes involved in phosphate metabolism (acid and alkaline phosphatases), and content of phytic acid and proline were determined in seeds of 20 cold stress tolerant and seven cold stress susceptible genotypes. Higher activities of superoxide dismutase, ascorbate peroxidase, catalase and acid phosphatase and low content of malondialdehyde and phytic acid were observed in cold stress-tolerant genotypes as compared to cold stress susceptible genotypes. Seventeen chickpea genotypes comprising both cold stress-tolerant and susceptible ones were evaluated through 20 randomly amplified polymorphic DNA (RAPD) primers. The results of cluster analysis revealed two major groups. In the first group five tolerant (group 1a) and six susceptible genotypes (group 1b) clustered together whereas in second group all the tolerant genotypes clustered together (group 2). Out of 20 RAPD primers, 4 primers (Opa-13, Opa-14, Opa-15 and Opa-16) have been identified as markers for cold stress tolerance. In general high SOD activity, and H2O2 content and low MDA and phytic acid content are related with cold stress tolerance. The status of these markers was more pronounced in genotypes clustered in group 2 after RAPD analysis than in group 1a of cold stress-tolerant genotypes as compared to susceptible genotypes. The observed biochemical and molecular diversity could be useful for identifying and developing cold stress-tolerant genotypes of chickpea.