Defining Selection Indices for Drought Tolerance in Chickpea under Terminal Drought Stresses

Abstract

Chickpea improvement for drought tolerance requires reliable assessment of drought tolerance variability among different
genotypes. In order to evaluate quantitative drought resistance criteria in some chickpea breeding lines, thirty five genotypes
were evaluated both under moisture stress (E1) and non-stress (E2) field environments using a randomized complete block design
for each environment. Seven drought tolerance indices including stress susceptibility index, stress tolerance index, tolerance,
yield index, yield stability index, mean productivity and geometric mean productivity were used. The significant and positive
correlations of Yp and (MP, GMP and STI) and Ys and (MP, GMP and STI) under both the seasons as well as significant negative
correlation of SSI and TOL in E1 revealed that selection could be conducted for high MP, GMP and STI under both environments
and low SSI and TOL under E1 conditions. The calculated correlation coefficients revealed that STI, MP, and GMP are the superior
criteria for selection of high yielding genotypes both under E1 and E2. Results of calculated gain from indirect selection indicated
that selection from moisture stress environment would improve grain yield in moisture stress environment better than selection from non-moisture stress environment.