Studies on Heterosis and Combining Ability for Growth, Yield and Quality Traits in Cucumber [cucumis Sativus L.]

Abstract

The present investigation “Studies on Heterosis and Combining Ability for Growth, Yield and Quality Traits in Cucumber [Cucumis sativus L.]” was conducted to assess the variability among the genotypes. The experimental material consisted of fifteen lines and five testers were crossed in line x tester and their resultant 75 F1s were assessed in a RBD with three replications during the year 2020-21. The observations were recorded in RBD for all the thirteen characters viz., number of primary branches, days to open first female flower, days to open first male flower, days to first fruit set, fruit weight, vine length, number of fruits per plant, number of seeds per fruit, total soluble solids and yield per plant. Analysis of variance for all the characters was highly significant. Therefore, there is a good scope for enhancement of the genotypes for all the characters. The mean performance of the parents and their hybrids revealed that the overall performance of the hybrids was superior to their parents. PCV was higher than the GCV for all the traits under the study. A perusal of genetic parameters revealed that number of primary branches, vine length and yield per plant exhibited high phenotypic and genotypic coefficient of variation suggesting that the existence of sufficient genetic variability for these traits in the population. Highest values for heritability were estimated for days to open first female flower followed by days to open first male flower, fruit length, days to first fruit set, number of primary branches, days to last fruit harvest and yield per plant. High heritability indicated that the traits were least affected by the environment. As a result, selecting these characteristics for improvement may be effective. High estimates of genetic advance as a per cent of means were observed for number of primary branches followed by yield per plant, vine length, fruit length, fruit weight, days to open first male flower, days to open first female flower and fruit diameter. High heritability and high genetic advance suggested that the traits were predominantly control by additive gene action. Yield per plant had positive and highly significant association with fruit weight followed by number fruits per plants, vine length, fruit diameter, fruit length, number seeds per fruit, total soluble solids and number of primary branches at genotypic level. Yield per plant had positive and highly significant association with fruit weight followed number of fruits per plant, vine length, fruit length, fruit diameter, number of seeds per fruit, number of primary and total soluble solids at phenotypic level. As a result of the study, it revealed that fruit weight followed by number of fruits per plant had high positive direct effect at both genotypic and phenotypic levels on yield per plant which indicated that fruit weight and number of fruits per plant are most vital characters in influencing yield per plant. In case of yield per plant, Heterosis over better parent the best five highest significant and positive values (desirable) were recorded for crosses Pusa Uday X Kalyanapur Green followed by Pant Khira-1 X Gujrat Cucumber-1, Pant Khira-1 X Pusa Long green, Pusa Barkha X DC-54 and Punjab Naveen X Himangi. In case of yield per plant, Heterosis over mid parent the best five highest significant and positive values (desirable) were observed for crosses Pusa Uday X Kalyanapur Green followed by Pant Khira-1 X Pusa Long Green, Pant Khira-1 X Gujrat Cucumber-1, Pusa Barkha X Gujrat Cucumber-1 and Pant Khira-1 X Swarana Ageti. The estimates of SCA variance were higher than GCA variance for fruit weight, number of seeds per fruit, days to last fruit harvest, fruit length, number of fruits per plant, number primary branches, vine length, yield per plant, fruit diameter and total soluble solids revealed prevalence of non-additive gene action. Whereas, estimates of GCA variance were higher than SCA variance for days to open first male flower, days to open first female flower and days to first fruit set were due to additive gene action. Significant GCA effects for parents Kalayanpur Green, PCUC-9, Swarana Ageti, Russion Picklies, JLG, Pusa Long Green and Pant Khira-1 were found good general combiners for yield per plant. the highest significant and positive values for SCA effects were observed for crosses Swarana Sheetal x Gujrat Cucumber-1, Pusa Uday x Kalyanpur Green, Pant Khira-1 x Pusa Long Green, Punjab Naveen x Himangi and Pant Khira -1 x Gujrat Cucumber-1 which showed good specific combiner for yield per plant.