Heterosis and potence ratio studies for yield and its contributing traits in cucumber (Cucumis sativus L.)

The present experiment was conducted to estimate the heterosis and dominance effects in the inheritance of fruit yield and its contributing traits in cucumber by using nine parents (6 lines and 3 testers) crossed in Line × Tester design. ANOVA for Line × Tester analysis revealed the presence of sufficient genetic diversity for different traits in the experimental material. The mid parent heterosis among different genotypes was obtained in both positive and negative direction for different traits under study. Maximum average heterosis was observed for the yield per hectare followed bytheseed vigour index II, number ofmarketable fruits per plant, severity of downy mildew, average fruit weight, harvest duration, severity of powdery mildew, node number bearing first female flower, fruit length, incidence of fruit fly, fruit breadth, seed vigour index I, total soluble solids, seed germination, days to marketable maturity and days to first female flower appearance. Partial to over dominance effects were involved in the inheritance of the studied traits. Hybrids estimated positive or negative potence ratio with >1 value is the indication of prevalence of over dominance in desirable direction and scope for exploitation via heterosis breeding in cucumber. Experimental results revealed that among 18 crosses, five crosses naming LC-1-1 × K-75, LC-1-1 × Poinsette, LC-2-2 × K-75, LC-2-2 × Poinsette and CGN-20515 × Poinsettewere found superior on the basis of overall mean performance and heterotic response for most of the traits. These hybrid combinations could be exploited commercially for the development of hybrids/varieties for better yield, quality (TSS), insect-pest & disease resistance and seed traits in cucumber.