Application of Drought Tolerance Indices for Grouping Advanced Barley Cultivars and Lines

Due to the droughts of the last few years, the low need of barley crop to water and rich soil, the need of the country in the supply of Community Food and the importance of barley in the food industry, therefore, it is necessary to introduce high-yielding and drought-resistant genotypes.

The research was conducted at the Ilam Agricultural Research Station in 2020-2021. Identification of tolerant and sensitive genotypes was based on grain yield and drought tolerance indices. Accordingly, 16 barley genotypes were implemented in the form of random complete blocks with four repetitions in two conditions: dim and supplementary irrigation. After harvesting, grain yield was measured and stress tolerance indices were calculated.

The results of correlation between drought tolerance indices and grain yield in rainfed and irrigated conditions showed that tolerance index (STI), mean productivity (MP), harmonic mean (HM) and geometric mean productivity (GMP) were positively correlated, and had significance with grain yield traits in both environmental conditions. So, they were suitable indicators for selecting high yielding genotypes in both rainfed and irrigated environments. Based on SIIG index, genotypes 11 and 9 show the highest values, while genotypes 3 and 4 had the lowest values. Also, factor analysis based on principle component analysis showed that the first two factors explain 98.5%((the first factor 68.7% and the second factor 29.8%) of the total diversity.

Based on the obtained results, genotypes No. 9 and 11 have the highest resistance to drought stress and yield, which are suitable for cultivation in areas under moisture stress, and genotypes No. 3 and 13 are suitable for planting in areas without moisture stress.