Genetic Study on Powdery Mildew Resistance and some Economic Traits in Melon (Cucumis melo L.)

The responses of seventeen melon (Cucumis melo L.) genotypes to powdery mildew pathogen (Erysiphe cichoracearum) were evaluated. The study was conducted at the experimental station of the Ismailia Research farm during the period from 2019 to 2020 to develop melon inbred lines and their hybrids resistance to powdery mildew to decrease injuries in yield and quality. Seventeen different inbred lines of melon were used to study genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), and environmental coefficient of variation (ECV), heritability and correlation, for twelve traits: number of leaves/plant, number of internodes/plant, number of branches/plant, tenth internodes length/plant, area of tenth plant leaf, fruit weight, fruit length, 1/2the diameter of the fruit, flesh thickness, total soluble solid (%), the average weight of seeds per fruit and 100-seeds weight. Inbred lines L1, L3, L10, L13, and L17 showed tope completely resistance to powdery mildew disease. Analysis of variance revealed high significance (P<0.05) for all characters. The results indicated the presence of substantial variability among the genotypes. Genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), and broad sense heritability (h²) estimates ranged from 11.14-60.69, 20.57-62.90, and 29.32-93.12% respectively. The high estimates of GCV and PCV in this study proved the existence of variability and the selection can be done. Whereas, the variation estimate of h² for the tested traits indicated that the selection in these characters were different