Investigation and Selection Index for Drought Stress

Considering the special position of durum wheat in terms of resistance to environmental stress and diseases and lack of water resources for cultivation of this plant so valuable study on drought resistance in plants is important. The objective of this study was to evaluate the ability of several selection indices to identify drought resistance cultivars under a variety of environmental conditions. Twenty two durum wheat lines and cultivars were evaluated under both 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 indices were adjusted based on grain yield under drought and normal conditions. The significant and positive correlation of Yp and MP, GMP and STI showed that these indices were more effective in identifying high yielding cultivars under different moisture conditions. The results of calculated gain from indirect selection from moisture stress environment would improve yield in moisture stress environment better than selection from non moisture stress environment. Wheat breeders should, therefore, take into account the stress severity of the environment in choosing an index