The Estimates of Heritability and Expected Genetic Advance by Using Analysis Generation Variances of Self – fertilizing Generations in Bread Wheat

Abstract

Four generations (F2 , F3 , Bs5 and Bs3) of two crosses in bread wheat , the first (S3- 69, S6 – 35) and the second (Germany X pandas), were used to study the components of variances , average degree of dominance , heritability and expected genetic advance form selction in the generations F2 , F3 , B1s and B2s for the quantitative traits : grain yield , number of per spikes , weight of 100 grains and number of grains per spike . The results of this study showed that the polygenes revealed over dominance for : (1) number of spikes and weight of 100 grains in the two crosses . (2) grain yield and number of grains per spike in the first cross . Broad and narrow sense heritabilities and expected genetic advance were high magnitude for some traits in the studied generations . Selection could used in the four generations to increase the frequency of desirable alleles for weight of 100 grains in the two crosses and recurrent selection could suggested to increase the frequency of desirable alleles for other traits .