Genetic variability and diversity studies in cucumber genotypes

Study on genetic variability and divergence was carried out on 35 genotypes of cucumber (Cucumis sativus L.). The analysis of variance revealed highly significant differences among genotypes for all the 30 characters studied. The PCV was more than GCV for all the characters studied indicating the environmental influence on the expression of the traits. Large variation was found for flowering and earliness parameters among the genotypes. All the characters showed high heritability in broad sense but genetic advance as per cent of mean (GAM) was varied among the characters suggesting different gene actions. By the use of Mahalanobis D2 analysis, genotypes were grouped into 5 distinct clusters. Cluster I comprised of 26 genotypes, cluster II with 6 and cluster III, IV and V were solitary with one genotype each. Among the five clusters, cluster I showed maximum intra-cluster diversity followed by cluster II. The clusters III, IV and V had no intra-cluster distance as these possess single genotype. Higher intra-cluster distance observed in cluster I signify the existence of wide genetic variability among the constituent genotypes in it as compared to other clusters.