SHARMA, HEM RAJTYAGI, NIDHI2020-09-222020-09-222020-08https://krishikosh.egranth.ac.in/handle/1/5810151745ABSTRACT The present investigation entitled “Genetic analysis of quantitative and qualitative traits in cucumber (Cucumber sativus L.)” was carried out at the HRS and KVK, Kandaghat, Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan, H.P. during pre-kharif seasons of 2017, 2018 and 2019. The experimental material comprised 18 F1 crosses, developed by crossing 3 gynoecious lines with 6 testers during the year 2017. During pre kharif 2018 and 2019, seeds of all the parents (3 lines and 6 testers) and their 18 F1’s along with the standard checks (KH-1) were planted in RCBD with 3 replications for their comparative analysis. The character studied viz., days to first female flower appearance, node number bearing first female flower, days to first fruit harvest, number of primary branches per plant, vine length (m), fruit length (cm), fruit breadth (cm), number of marketable fruits per plant, average fruit weight (g), marketable fruit yield per plant (kg), seed cavity size (cm), 100 seed weight, total soluble solids (°Brix), total sugar (%), ascorbic acid content (mg/100 g), severity of downy mildew (%) and severity of powdery mildew (%).The analysis of variance showed the significant differences among all parents and cross combinations for all the traits. Experimental results revealed that lines KTG 40, 2870 G and testers K-90 and UHF-16 were superior on the basis of mean performance and general combining ability therefore, could be potential donors in breeding. The cross combinations KTG 40 × K-90, 2870 G × K-90, KTG 40 × UHF-16 and 2870 G × UHF-16 were identified as having promise based on mean performance, heterosis and specific combining ability. Estimates of σ2s were higher in magnitude than those of σ2g (average), or variance ratio <1 and predictability ratio <0.5 found for all the traits thereby, indicating the predominant role of non-additive gene action governing these traits. Partial to overdominance response in inheritance of most traits contributes to the genetic basis of heterosis. Therefore, heterosis breeding could be exploited commercially for the development of high-yielding, quality, downy mildew and powdery mildew disease tolerance gynoecious hybrids in cucumber.EnglishThesis