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

Abstract

The present experiment was conducted to estimate themheterosis and dominance effects in the inheritance of fruitmyield and its contributing traits in cucumber by using ninem parents (6 lines and 3 testers) crossed in Line × Tester design. ANOVA for Line × Tester analysis revealed thepresence 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 by the seed vigour index II, number of marketable  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 × Poinsette were 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.