Enumeration of Genetic Parameters and Genetic Diversity of Morpho-Physiological Traits in CIMMYT Bread Wheat Accessions [Triticum aestivum (L.) em. Thell]

Fifty genotypes of CIMMYT bread wheat were evaluated at Agricultural Research Farm, BHU, Varanasi during 2019-2020.The analysis of variance revealed significant differences among genotypes for all traits. High Phenotypic coefficient of variation was recorded compared to the genotypic coefficient of variation. However, high genotypic coefficients of variation were found particularly for: grain yield per plot (8.71), harvest index (9.22), test weight (8.9), normalized difference vegetative index (9.59) and chlorophyll content (9.79), suggesting that these traits are having ample genetic potential for selection amongst genotypes, in breeding programs. The highest broad sense heritability manifested for harvest index (91.61%); remaining traits showed moderate estimates of heritability. Low to moderate genetic advance as percent mean was estimated for all the traits studied. This suggests the existence of variability for agronomic traits in the studied wheat genotypes which, should be exploited during future breeding programmes. Fifty genotypes were divided into six non-overlapping distinct clusters using tocher's method based on Euclidean distances. Thirty-one genotypes were classified in the first cluster accounting 62% of total genotypes followed by 15 genotypes categorized in the second cluster. The remaining four clusters have one genotype each. Divergence and cluster mean show that, crossings between genotypes of clusters (II, III), and VI could lead to recovery of good transgressive segregants for maximum heterosis in wheat varietal improvement.