Effective selection criteria for assessing drought tolerance in chickpea

الملخص EN

Ten chickpea genotypes were evaluated at two separate field experiments conducted during spring growing season 2011 under non-stress and stress conditions.

Some drought tolerance indices such as tolerance index (TOL), mean productivity (MP), harmonic mean (HM), stress susceptibility index (SSI), geometric mean productivity (GMP), stress tolerance index (STI), yield index (YI), yield stability index (YSI) and modified stress tolerance index (k1STI and k2STI) were calculated based on seed yield under non-stress (Yp) and stress (Ys) conditions.

In addition to laboratory experiment included the effect of three osmotic potentials (0, – 0.4, and – 0.8 MPa) on germination and early seedling growth of these genotypes.

The aim of this study is to determine the best index and also identifying the best drought tolerance chickpea genotypes.

Genotypic correlation, genetic components and heritability were calculated for seed yield and all indices, as well as path coefficient analysis and selection indices were carried out for some tolerance indices including seed yield.

Significant differences among genotypes were observed for Yp, Ys and all other drought tolerance indices.

High heritability and genetic advance were observed for Yp, Ys and most of drought tolerance indices.

Yp and Ys was positively and significantly genetic correlated with GMP, HM, MP, STI, k1STI and K2STI.

Path coefficient analysis revealed that the same indices (YI, and K1STI) exhibited positive direct effects on seed yield under non-stress and stress conditions.

The most effective indices have relative efficiency up to 37.785% and 6.338% over the direct selection were obtained (TOL, K1STI) and (Ys, K2STI) under both non-stress and stress conditions, respectively.

Regarding to laboratory experiment, the germination and seedling growth were significantly inhibited at higher osmotic potentials compared to control.

Based on results of field and laboratory experiments, three genotypes were selected which are superior in most of drought tolerance indices and germination and early seedling growth under osmotic potential and can be recommended for cultivation in semi-arid areas or used in breeding programs in the future.