Assessment of Genetic Variability for Physiological Traits and Yield in Bread Wheat (Triticum aestivum L. em. Thell.)

The present investigation was carried out with 32 diverse genotypes of bread wheat in completely randomized block design with 3 replications at Norman E. Borlaug Crop Research Centre, G.B. Pant University of agriculture & Technology Pantnagar for the screening of genetic variability under three environments viz., timely sown (E1), late sown (E2) and very late sown (E3) seasons. The observations were recorded on 16 agronomic traits and 3 physiological traits. The statistical analysis for genetic variability was done using ANOVA, h2, GCV, PCV, GA and genotypic correlation. The analysis of variance was carried out for all the characters in randomized block design indicated highly significant differences among treatments for all the characters under study. High heritability values were observed in all the characters studied except grain filling duration in which heritability was moderate. High ECV was observed for characters such as canopy temperature depression-I, canopy temperature depression-II, canopy temperature-III, and canopy temperature depression-IV. Characters plot yield, canopy temperature depression-I, and canopy temperature depression-IV were marked with high GCV. Characters days to 75% heading, days to 75% anthesis, days to 75% maturity, grain yield per plant, plot yield, canopy temperature depression-I, canopy temperature depression-II, canopy temperature depression-III, and canopy temperature depression-IV exhibited high PCV values. The genetic advance was observed high for plot yield. There were highly significant positive as well as highly significant negative correlations were observed among physiological and yield related traits. The CTD-I, III, IV, and relative water content had shown highly significant positive correlation with days to 75 % heading and days to 75 % anthesis. CTD-III, IV, SPAD and relative water content were also marked with highly significant positive correlations with different yield attributes. The genotypes bearing the desired values for different genetic variability parameters can be exploited in future breeding programme for the improving wheat genotypes. These genotypes can be used as donor parents in crop improvement programme.