Genetical Analysis of variances for Early Generation in Bread Wheat (Triticum aestivum L.)

Six early generations (P1,P2 ,F1,F2,B1,and B2) of two crosses in bread wheat (Triticum aestivum L.). Pandas Gemeney and S3- 69 S6-S3 , were used to study components of variances for maturity time ,plant height ,flag leaf area, grain yield and its components. The phenotypic variance for the studied characters in six generations for each cross was analyzed to estimate : additive genetic variance, dominance genetic variance, environmental variance, average degree of dominance, additive dominante genetic covariance, heritability and expected genetic advance from selection in F2 generation. Average degree of dominance revealed all the types of dominance for the studied traits. The dominant genes for most of the traits were found in pandas and S3-69. The values of narrow sense heritability was high and significant for : number of spikes and grain yield in the first cross,spike length , weight of 100 grains and number of grains per spike in the second cross : Dricet selection can be used to improve the spik length in the first cross. Recurrent selection can be used to increase the frequency of the desirable alleles for other traits.