In situ MORPHOLOGICAL VARIATION OF Carica papaya L. NATIVE TO MEXICO

Abstract

In Mexico there are wild and domesticated populations of Carica papaya; however, studies related to its variation in situ have been limited in number of both individuals and geographic areas. The objective of this study was to characterize in situ the morphological variation of C. papaya specimens native to Mexico. Twelve morphological characteristics (six quantitative and six qualitative) of fruits collected from 222 specimens of C. papaya from 10 states of the slopes of the Pacific and the Gulf of Mexico were evaluated. Analysis of variance, principal component (PCA) and hierarchical grouping with euclidean distances were performed. According to the analysis of variance, all the morphological characteristics between accessions showed significant differences (P ≤ 0.01). The PCA revealed that the characteristics of greater contribution to the variation among the evaluated specimens were edible volume, diameter of the central cavity, length, diameter, thickness of pulp, shape of the peduncular end and fruit shape. The cluster analysis formed three statistically different phenotypic groups (P ≤ 0.01) and detected continuity based on the dimensions and shape of the fruit. Both multivariate analyses showed differences between the wild and domesticated types collected in homegardens. The high morphological variability among C. papaya is appropriate to establish a national germplasm conservation program of genotypes with genetic dissimilarity to be used in breeding programs.