Genetic diversity in qualitative and quantitative traits of papaya

Abstract

The present study was conducted for the diversity analysis of 11 dioecious genotypes of papaya based on various morphological traits. A significant range of variation was noticed for stem colour, which varied from green to greenish light grey in majority of the studied population. The genotype P-9-15-5 was observed with an extreme variation in stem colour i.e., purple pink. For stem pigmentation a predominantly indiscriminate pattern was recorded in most of the genotypes whereas two genotypes namely, P-15-1 and P-9-15-5 were distinct with purple colour pigmentation on the stem of the female and male plants. Leaf petiole colour was primarily light green to green in most of the genotypes, whereas in case of genotype P-9-25, P-14-9 and P-15-2, it was noticed green with shades of purple. Petiole sinus shape varied from slightly open to strongly closed. The wild relative of papaya genotype V. cauliflora was distinct with other genotype with open shape of petiole sinus shape. The mature leaf teeth shape for all the genotypes of papaya was of two types i.e., straight and convex type. Genotype V. cauliflora, RCTP-I, Pusa Dwarf, Pusa Nanha, P-15-1, P-14-6, and P-9-15-5 were with straight mature leaf teeth shape whereas convex leaf teeth shape was recorded in P-9-25, P-14-9 and P-15-2. Inflorescence stalk colour varied from light green to green for all the studied genotypes. Flower colour varied from cream, yellowish white to white in colour in both female and male sexes of the plants. The wild relative, mountain papaya (V. cundinamarcensis) was most distinct genotype among the dioecious population studied. In UPGMA dendrogram based on quantitative traits of dioecious papaya revealed wide distinctness between V. cauliflora and V. cundinamarcensis.