Harnessing genetic diversity in papaya: Cluster analysis and its implications for breeding 

Abstract

A comprehensive study was conducted at the Horticultural Research Centre, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, to evaluate genetic diversity among 54 papaya genotypes, including 14 Parents and 40 F1 hybrids developed through a Line × Tester mating design. The research aimed to analyze inter- and intra-cluster distances, cluster means, and associated genetic traits under the subtropical climatic conditions of Meerut. Observations encompassed key agronomic and quality parameters such as flowering time, fruit yield, pulp thickness, and total soluble solids (TSS), with data analyzed using Mahalanobis' D² statistic and Tocher's method for cluster grouping. Five distinct clusters were identified, with significant genetic divergence observed between Clusters I and IV (inter-cluster distance: 6.976), suggesting potential for hybridization to enhance genetic variability. Cluster IV demonstrated superior performance in yield-related traits, with the highest fruit yield per plant (60.52 kg), heavy fruits (2.48 kg), thick pulp (3.70 cm), and large fruit diameter (55.05 cm), making it a prime candidate for improving yield and quality. Cluster I excelled in early flowering (95.45 days) and dwarf plant height (78.38 cm), offering opportunities for developing compact, early-maturing varieties. Cluster V, the largest group, exhibited high genetic variability, ideal for breeding programs targeting diverse traits. These findings underscore the importance of genetic diversity for targeted papaya breeding. Strategic selection of genotypes from clusters with complementary traits can address specific breeding goals, including high yield, superior fruit quality, compact growth habit, and early maturity, ensuring the development of improved papaya varieties for diverse agricultural and market demands.