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

To assess the drought tolerance in advanced durum wheat lines, 20 genotypes were evaluated in a randomized complete block design with three replications under non-stress and drought stress conditions during 2009-2010 cropping season. Analysis of variance showed significant differences among genotypes for grain yield in two environmental conditions (non-stress and stress). The maximum grain yield under stress and non-stress conditions belonged to lines No. 13 (808.3 gm-2) and No. 14 (1177 gm-2) respectively. Investigation of correlation between yield in two conditions and drought resistance indices showed that STI, MP and GMP were desirable for identifying high yielding genotypes in two conditions, and the best index was STI. According to drawing of bi-plot, the genotypes were placed into tolerant and non-tolerant groups, as genotypes No. 4, 5, 10, 11, 14 and 15 were placed in area with high yield potential, low sensitive to drought, and near to MP, GMP and STI vectors, and genotypes No. 6, 16, 17, 19 and 20 were placed in area with low yield and high sensitive to drought. Based on cluster analysis and discrimination analysis according to desirable indices (MP, GMP and STI), genotypes were divided into 5 different groups. Finally based on drought resistance indices genotype No. 14 was determined as drought tolerant genotype.