Evaluation of drought stress tolerance based on grain yield, grain yield components and drought tolerance indices in cold rainfed spring barley genotypes

Drought stress is one of the major limiting factors for crop production worldwide. The purpose of this research was to evaluate the effect of drought stress on grain yield, grain yield components and evaluation of drought tolerance indices in several spring two-row barley genotypes and cultivars of cold areas. The genetic materials were evaluated in a factorial experiment based on randomized complete blocks design with three replications. The factors included thirteen rainfed spring two-row barley genotypes and cultivars from cold areas with different origins and various irrigation levels (complete irrigation and irrigation based on 60% and 80% depletion of available soil water). The results showed that with increasing the level of drought stress, grain yield and grain yield components decreased. Based on all results at both stress levels, two genotypes originated from Pakistan and Iran and Abidar cultivar and Dayton / Ranney cultivar (improved by ICARDA) were identified as drought-tolerant genotypes. Also, a genotype originated from Ethiopia and Denmark cultivar (improved by ICARDA) failed to produce an acceptable yield in normal condition irrigation but Ethiopian genotype was able to tolerate 60% depletion of available soil water stress and Denmark cultivar could tolerate 60% and 80% depletion of available soil water stress. Also, the results of principal coordinate and cluster analyses for yield, yield components traits and drought tolerance indices were in complete agreement. The best indices for recognition of the superior genotypes in terms of drought tolerance under 60% and 80% depletion of available soil water stress were GMP, MP and STI indices. Therefore, after completion tests under drought stress in real rainfed conditions in cold and drought or semi drought areas, these genotypes can be introduced in breeding programs of barley cultivars under adverse and unpredictable rainfed conditions in cold and drought or semi drought areas.