Assessment of genetic diversity in khirni [Manilkara hexandra (Roxb.) Dubard]: An important underutilized fruit species of India using Random Amplified Polymorphic DNA markers

Manilkara hexandra (Roxb.) Dubard (khirni), is an important underutilized fruit species from western and central India with high potential as commercial horticultural crop. Agro-morphological characters and random amplified polymorphic DNA (RAPD) markers were used to estimate genetic variability in 23 diverse accessions of this species. Fifteen RAPD primers were used which generated a total of 119 bands, out of which, 103 bands (78%) were polymorphic revealing substantial genetic diversity within this species. Similarity value among all the M. hexandra accessions ranged from 0.52 to 0.82 with an average of 0.68. Dendrogram of 23 accessions revealed two main clusters. Principle Component Analysis (PCA) also showed almost similar grouping patterns with the dendrogram. The results obtained from morphological and RAPD analyseis indicated the presence of substantial genetic diversity among the khirni genotypes. The out-crossing nature of this species is responsible for the presence of high level of genetic diversity providing rich genepool for selecting genotypes with desirable characters for commercial exploitation. The most promising accessions identified based on desired horticultural attributes and RAPD analysis were IC-552938, IC-552940, IC-552918 and IC-552953. These accessions needs to be further evaluated and could be used either as direct selections or in the improvement of this fruit species.