Estimation of some genetic parameters through generation mean analysis in melon

This study was done to determine the types and magnitude of gene effects and heritability of some yield and physiological traits in melon (Cucumis melo L.). After generating of F₁, F₂, BC₁ and BC₂ generations from the meeting of the two parents, Tashkandi (P₁) and Alien (P₂), the six generations were used in the generation mean and variance analysis. The experiment was carried out in a randomized complete block design with three replications. The results indicated that, additive gene effect was significant for fruit length, seed length and TSS. The significant additive and dominance effects was observed in fruit diameter, fruit length/diameter ratio, flesh thickness and skin thickness. Significant additive×additive effects was detected for all traits except TSS. Additive×dominance gene effects was significant for fruit length, fruit diameter, fruit length/diameter ratio and seed length. Dominance×dominance significant effects were detected for flesh thickness, skin thickness and TSS. The additive genetic variance estimates for fruit length, fruit length/diameter ratio, flesh thickness, skin thickness and seed length were positive and the dominance variance estimates for these traits were negative or small. In contrast, in fruit diameter and TSS dominance variances were high. So, narrow sense heritability was high for all traits except fruit diameter and TSS. These results indicate that selection may be more effective for improving traits of genotypes in early generations