Evaluation of Some Egyptian Barley Cultivars under Water Stress Conditions Using Drought Tolerance Indices and Multivariate Analysis

Abstract

The present work was carried out in two separate field experiments of Sakha Research Farm during two growing seasons 2012/2013 and 2013/2014 to evaluate 15 barley cultivars under normal and water stress conditions. The results indicated that the cultivars Giza 2000, Giza 126 and Giza 131 had the highest performance for most of the studied traits under normal and water stress conditions. Also, these cultivars exhibited highly significant differences for all drought tolerance indices. First principal component analysis (PCA1) contributed 76.1% of the total variation with high positive values of grain yield under normal (Gyp), under water stress conditions (GYs), yield index (YI) ,stress tolerance index (STI), mean product (MP), geometric mean product (GMP) and harmonic mean (HM) indices while had negative values with tolerance index TOL and stress susceptibility index (SSI), but second PCA2 explained 23.0% of the total variability. Biplot diagram and cluster analysis divided the cultivars into four groups A, B, C and D based on the basis of PCA1 values, PCA2 values, GYp, GYs and selection drought tolerance indices. So, the cultivars which are found on A region, had high yield under both normal and water stress conditions, so we could consider these cultivars Giza 2000, Giza 126 and Giza 131 as water stress tolerant and we recommend them for using in breeding program for high yielding under normal and water stress conditions, and consider YI, STI, MP, GMP and HM as major and suitable indices for selecting cultivars with high yield at both environments.