Dissection of Genetic Diversity in Local Collections of Cucumis melo and Cucumis sativus Germplasm for Growth and Yield Traits

Abstract

One hundred and fifty cucumis species genotypes were collected from different states of India of which 116 were Cucumis melo and 36 were Cucumis sativus types and were evaluated for yield and qualitytraits at College of Horticulture, Bagalkot during Kharif season of 2019.The genetic diversity of 150 cucumber genotypes was evaluated in a Augmented Block design to assess the extent of diversity within and between the cucumis species. Mahalanobis D2 statistic revealed wide diversity among the melo and sativus species. Eight clusters were formed and this clustering based on eighteen quantitative traits and interactions in genetic distances. Among the 8 clusters, the Cluster I was the largest and composed of 66 collections, followed by cluster II with 34 collections and least number of genotypes in clusters VIII with 3 genotypes indicating that large amount of diversity. The highest intra cluster distance was observed in cluster VII (D2=10537.96) and lowest was observed in cluster I (D2=3807.4) and in cluster VII (D2=0.000) indicating the presence of solitary clusters. The highest inter-cluster distance was observed between for cluster VII and cluster V (D2=89964.23) and lowest was reported in cluster IV and Cluster I with a D2value of 8248.25. Maximum contribution towards genetic divergence was from number of fruits per plant (12.2%) Lowest contribution reported by number of nodes per vine (1.0%).Genotypes from different geographic regions were grouped in random fashion, suggesting that there was no correlation between geographic distribution and genetic diversity. D2 statistics revealed the presence of substantial genetic diversity within the melo compared to sativus types.