Estimation of genetic variability for different quantitative characters under heat stress condition in bread wheat (tritium aestivum L.) genotypes.

The current investigation comprising of 108 various genotypes of bread wheat were assessed to detect appropriate and high yielding genotypes under heat stress situation. The experiment was conducted during Rabi 2014-15 and Rabi 2015-16 in RBD having three replications under heat stress condition. The data were noted on 16 quantitative and physiological characters to work out tolerant genotypes under heat stress condition. The analysis of variance revealed highly significant differences among 108 genotypes for all the sixteen quantitative and physiological characters under study, this point to the existence of adequate variation in the present gene pool. High heritability accompanied by high genetic advance will be more helpful to arrive at more reliable conclusion. It can be determined that the present research revealed that many traits have adequate genetic variability for the various agronomic characters among genotypes. Study showed effectiveness of germplasm for further use in breeding program. Lower genetic advance limits the greater scope of improvement but higher phenotypic and genotypic coefficient of variation and higher heritability provides good chance for its further improvement. Effective selection is dependent on a high heritability of a character. In the present study heritability was ranged from (0.30) to (0.95) which was recorded for harvest index and chlorophyll content respectively.