Assessment of genetic variation among bread wheat genotypes based on yield-related traits

Genetic diversity is a base for the survival and improvement of crops. This experiment was conducted to evaluate genetic diversity among 400 bread wheat genotypes based on nine quantitative yield-related traits. The results of descriptive statistics showed that the highest and lowest amount of phenotypic variation belonged to kernel weight per spike (34.61%) and kernel length (7.61%), respectively. Correlation coefficient analysis showed a strong and positive correlation between kernel weight and spike weight (0.97) followed by the number of kernels per spike and number of kernels per spikelet (0.91). Principal component analysis reduced the nine traits into three principal components that explained 85 percent of the total variation. Factor analysis revealed three underlying factors that explained 86 percent of the variation. Cluster analysis based on all the studied traits divided the genotypes into four clusters. The first cluster included 145 genotypes and had the lowest means for most of the traits. The second cluster included 43 genotypes and had the highest mean for kernel length. The third cluster included 77 genotypes that had the highest means for spike weight, kernel weight per spike, kernel width, and thousand-kernel weight. The fourth cluster included 135 genotypes and had the highest means for spike length, number of spikelets, kernels per spikelet, and kernels per spike. The results of this study can contribute to the understanding of genetic diversity among bread wheat genotypes and can be used for bread wheat improvement programs.

Assessment of genetic variation among bread wheat genotypes based on yield-related traits Keywords:

Bread wheat , Genetic diversity , Morphological traits , Multivariate analysis