Genetic Divergence Studies in Cucumber (Cucumis sativus L.) Genotypes for Yield and Quality

Abstract

Background: In an effort to identify divergent superior parents for hybridization programme, a study to examine the genetic divergence in yield and quality traits was conducted. Methods: Thirty two cucumber genotypes were collected from different states of India and were evaluated for yield and quality characters at Bhubaneswar, Odisha during Rabi season of 2019. Result: The genetic diversity of 32 cucumber genotypes was evaluated using a randomized block design. The Mahalanobis D2 statistic revealed the presence of substantial genetic diversity among the 32 genotypes examined. In a study of 32 cucumber genotypes, clustering based on interactions in genetic distances revealed substantial genetic divergence among the groups. Genotypes from different ecogeographic regions were distributed into distinct clusters in an apparently random fashion, suggesting that there was no correlation between geographic distribution and genetic diversity. Cluster I included the most unique genotypes, suggesting that it was a major contributor to the overall genetic divergence among the five groups. Results showed that Clusters II, IV and V were all monogenomic. Cluster II, IV and V had the smallest intra-cluster distances (0.00), whereas cluster I had the largest (45.08). There was the greatest genetic distance (133.68) between cluster’s I and V, suggesting that cluster V could be used in a future hybridization study. Clusters IV, V and III had the highest mean values of the five clusters for many of the characteristics. According to the ranking of D2 value, the contribution of fruit yield per vine (16.50%) towards genetic divergence was highest. Therefore, phenotypic selection could be used to further enhance this trait.