Genetic Variability and Association Studies for Morpho-Physiological and Quality Traits in Wheat Genotypes

Genetic variability is the foundation for adaptation of populations in the context of environmental changes. This study evaluated the morpho-physiological and quality traits of 194 wheat genotypes under timely sown irrigated conditions during crop season 2023-24 at Chaudhary Charan Singh Haryana Agricultural University, Hisar (Haryana). The genotypes were assessed using an Augmented Design with a plot size of 2.5 m x 0.4 m. The results revealed significant mean sum of squares due to genotypes for all the traits under study except flag leaf length and canopy temperature depression at 15 days after anthesis. The estimates of phenotypic coefficient of variation were observed slightly higher than their corresponding genotypic coefficient of variation for all the studied traits, indicating a small effect of environment on the expression of these traits. Heritability in broad sense was found to be high along with higher genetic advance as a percentage of the mean for biological yield per plot, number of tillers per meter, grain yield per plot, spike length, 1000-grain weight, number of grains per spike, awn length, gluten content, sedimentation value and crude protein. Association study reflected significant and positive correlation of grain yield with days to physiological maturity, flag leaf length, flag leaf breadth, number of tillers per meter, spike length, peduncle length, number of spikelets per spike, number of grains per spike, biological yield per plot, grain filling duration, harvest index, 1000-grain weight, chlorophyll content, relative water content and hectolitre weight. Path coefficient analysis demonstrated highest positive direct effect of biological yield per plot on grain yield followed by gluten content and harvest index. These findings hence may be explored in future breeding strategies intended to improve the target trait and to develop high yielding varieties.