Evaluation of Drought Tolerance in Durum Wheat Genotypes Using Drought Tolerance Indices

Abstract

Drought has become challenging globally, particularly under rain-fed crop production systems of Ethiopia. It is one of the major causes for wheat  yield reduction. One hundred forty-four durum wheat genotypes were evaluated at Debre-Zeit experiment station in 2017 dry season, under  drought stressed and non-stressed environments, to identify drought tolerant genotypes and suitable drought screening indices. The trial was  conducted during the off-season. Based on grain yield under stressed and non-stressed conditions, various drought tolerant indices including  Abiotic tolerance indices (ATI), Geometric mean productivity (GMP), Stress tolerance indices (STI), Stress stability indices (SSI), Tolerance indices  (TOL), Yield index (YI) and Drought resistance indices (DRI) were computed. The combined analysis of variance showed that moisture, genotypes and  their interaction had a significant (p≤0.01) effect on grain yield. Principal component and Correlation analysis indicated that DRI, YI, YSI and REI,  as important indices highly correlated with grain yield under stress suggesting their suitability to identify drought tolerant genotypes. Cluster  analysis also grouped the genotypes into five different clusters having various characteristics. Overall, evaluation of durum wheat genotypes for  drought stress using different analysis identified G-16, G-763, G-31, G-119, G-63 and G-30 as drought tolerant genotypes. DRI, YI and YSI could be  regarded as good indices for the identification of drought tolerant lines. MP, GMP, and REI were the best indices to identify suitable genotypes to  both drought and non-drought stressed environment.