Biochemical Assessment of Chickpea Genotypes for Drought Tolerance in Relation to Osmolytes and Limiting Amino Acids in Protein

The present research work was carried out with a view to evaluate the levels of crude protein, methionine and tryptophan from the defatted meal of ten each of drought tolerant and susceptible chickpea genotypes. In addition, the contents of proline, glycine betaine, and the activity of Δ¹–pyrroline-5-carboxylate synthetase (P5CS) along with soluble protein contents were determined in the leaves of these genotypes by imposing -0.5 MPa stress created by PEG-6000. Further, the extracted soluble proteins were resolved on a denaturing polyacrylamide gel in order to observe the differences in banding patterns under stressed condition. The seeds of a drought tolerant genotype recorded the mean crude protein, methionine and tryptophan content of 22.08 per cent, 0.78 g 16g⁻¹ N and 0.61 g 16g⁻¹ N, respectively. Amongst the drought susceptible ones, the mean crude protein, methionine and tryptophan content was 23.43 per cent, 0.78 g 16g⁻¹ N and 0.63 g 16g⁻¹ N, respectively. The increased stress reveled significant accumulation of proline in drought tolerant genotypes. The genotype PG-96006 showed the highest increase in proline content in addition to increase in P5CS activity and glycine content. The increased stress did not reveal significant differences in soluble protein contents in the leaves of drought tolerant and susceptible genotypes. The drought tolerant genotype such as PG-96006, Annegeri and Vijay with comparatively higher potential to accumulate proline and glycine betaine could be further exploited for introgression of drought tolerance character in the existing germplasm.