Evaluation of Durum Wheat Lines using Seed Yild based Indices in Drought Condition and relation between these Indices

In order to study tolerance of durum wheat (Triticum durum) lines to drought stress and also evaluating stress tolerance indices, an experiment based on randomized complete block design with four replications was conducted under two rain fed and supplementary irrigation conditions at Gachsaran station during 2011-2012 cropping season using 20 durum wheat lines. Results of combined analysis of variance for seed yield showed significant differences (p≤0.01) between lines and interaction between lines and environment. The yield based indices were calculated in rain fed and supplementary irrigation conditions. With considering of significant positive correlation between grain yield in the rain fed condition (YS) with geometric mean productivity index (GMP), mean productivity index (MP), stress tolerance index (STI), yield index (YI), drought response index (DRI), drought resistance index (DI), harmonic mean (HM) and modified stress tolerance index (K1STI), these indices were suitable criteria for identification of drought tolerant lines. Also, tolerance index (TOL), yield stability index (YSI), stress susceptibility index (SSI), relative drought index (RDI), abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI) and stress non-stress production index (SNPI) didn’t have important role in the differentiation of lines. Grouping of lines using cluster analysis method showed that the lines 3 and 13 had high yield and were tolerant rain fed condition and the lines 7 and 18 were sensitive to rain fed condition. The results from grouping of lines using three dimensional graphs based on yield in rain fed and supplementary irrigated condition and STI index were same as cluster analysis.