Evaluation of Yield and Yield Components in Promising Wheat Lines using Multivariate Statistical Methods

Wheat (Triticum aestivum L.) is the most important crop and staple food of three quarters of the world's population. Therefore, the study of genetic diversity of this strategic plant helps breeders to identify the genetic potential and capacity of traits related to breeding goals, including yield and yield components. Knowing the differences between different wheat genotypes and how these differences relate to their potential yield is crucial in improving the yield of new cultivars.

In order to achieve the desired wheat genotypes, study of genetic diversity of yield, yield components and interaction of genotype × treat of 21 promising wheat lines in terms of 14 important agronomic traits in a randomized complete block design (RCBD) in three replications with important commercials cultivars of the region (Tirgan and Kalateh) as controls, was performed. The experiment was planted in the Agricultural Research Station of the Ardabil Agricultural and Natural Resources Research and Education Center (Moghan). Among the existing methods for evaluating diversity, multivariate analysis is one of the most important and widely used methods.

The results of analysis of variance at the probability level of 0.01 and 0.05 indicated that the studied wheat lines had significant differences in all traits except the number of grains per spike. Comparison of the mean performed by Duncan method also showed that G17 and G15 lines were selected as desirable lines in terms of all measured traits; while, G3 and G19 lines also had the lowest rank in this analysis. The results of correlation analysis also showed that the grain yield had a positive and significant correlation with all the evaluated traits except the number of tillers, peduncle length and number of grains per spike. Based on the principal component analysis performed on the experimental data, the first 5 components explained more than 75% of the variance of the data. According to the grouping diagram of the lines in terms of the first and second components, the lines were grouped into four groups. Based on the graphical analysis of the line ranking chart, the promising wheat lines G15 and G17 had better performance in the evaluated traits than the other studied lines, and the G4 line in terms of stability in the traits, as stable line, was selected. The multidimensional diagram also identified G15, G17, G18, G23, G6, G10 and G12 lines as desirable genotypes, and in terms of line ranking diagram based on the ideal line, G15 and G17 lines were also identified as the top ranking line.

Lines with high yield potential and other desirable agronomic traits identified in this study can be used to create superior populations and compatible with the characteristics of hot and humid zone in the north of the country.