Appraising of barley promising lines relying on high grain yield and desirable agronomy traits in rainfed conditions using SIIG and ASIIG techniques

This study aimed to investigate the genetic diversity of 140 barley advanced lines, using Selection Index of Ideal Genotype (SIIG) and Adjusted Selection Index of Ideal Genotype (ASIIG) indicators for introduction and cultivation of suitable lines in rainfed conditions. The highest coefficient of variation was related to the type of spike, flag leaf area, seeds per spike, peduncle length, flag leaf width, and early growth vigor. The stepwise regression showed that the early growth vigor, 1000-seeds weight, spike type, days to heading, plant height, number of seeds per spike, and flag leaf length were the most critical components, which affect the grain yield under the rainfed conditions. The results of SIIG showed that lines 4, 43, 47, 40, 70, 96, 137, 3, 57, and 45 were the best lines with the highest SIIG values. The SIIG index divided all lines into seven groups; the average grain yield of lines in groups I and II were higher than the average grain yield of control cultivars and the other groups. According to ASIIG plots, lines 47, 3, 43, 45, 137, 96, and 40 were placed in the ideal quarter. Finally, the SIIG and ASIIG were compatible in selecting the best lines. ASIIG was more suitable for separating the ideal lines, because it participated all traits commensurate with their importance in the end product quantity and quality.