DPPH radical scavenging activity and contents of H2O2, malondialdehyde and proline in determining salinity tolerance in chickpea seedlings.
The involvement of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and contents of H2O2, malondialdehyde (MDA) and proline was investigated in determining salinity tolerance among seedlings of thirty chickpea (Cicer arietinum L.) genotypes having different pedigrees. Chickpea genotypes, including cultivars and advanced lines were grown for 7 days under control and salt stress (50 mM NaCl) conditions. The genotypes showed differential response to salt stress in terms of growth, DPPH radical scavenging activity and contents of H2O2, MDA and proline in seedlings. On the basis of seedling growth, the genotypes having better performance under stress conditions had reduced levels of H2O2 and MDA contents, but increased levels of proline and DPPH radical scavenging activity. Stress tolerance index for these parameters was also determined. Agglomerative hierarchal clustering by Pearson correlation coefficient grouped the genotypes into two major clusters--MC I and MC II. MC II and Al-1 sub-cluster of MC-I comprised mainly of genotypes that showed higher stress resistance levels for the respective parameters in comparison to genotypes in other sub-clusters. Thus, it is possible to identify salt-tolerant genotypes on the basis of above parameters without a field trial.