Assessment of genetic diversity of mango (Mangifera indica L.) cultivars from Indian Peninsula using Sequence Tagged Microsatellite Site (STMS) markers.
Ravishankar K. V., Dinesh M. R., Mani B. H., Padmakar B., Vasugi C.
Author Affiliation: Indian Institute of Horticultural Research, Hesarghatta Lake Post, Bangalore, India.
Abstract : India has been considered as the world's richest germplasm centre for mango (Mangifera indica L.). Mango is being cultivated in India for thousands of years. In India, mango gene pool has not been explored with regard to extent of variability, identification, collection and conservation of germplasm. This necessitates mango germplasm characterization for its conservation and improvement. Genetic diversity and relationships among 269 mango (Mangifera indica L.) cultivars of Indian peninsula was evaluated using Sequence Tagged Microsatellite Site (STMS) markers. Microsatellite markers were developed for studying genetic diversity in our lab. Fourteen microsatellites, which showed high PIC values, were used for the analysis of 269 mango cultivars. The results of genetic analysis showed that the allele size ranges from 11 to 39 with an average of 24.21 alleles per locus. The observed heterozygosity (H0) ranged from 0.249 to 0.773 with mean of 0.584, expected heterozygosity (He) ranged from 0.653 to 0.941 with mean of 0.854. PIC values ranged from 0.593 to 0.936 with mean of 0.838. Probability of identity for 14 microsatellite loci was 5.45×10-19. Dissimilarities among genotypes were calculated using simple matching coefficient. A dendrogram was constructed following Neighbour Joining methodology using DARWin software. Dendrogram analysis classified mango cultivars into two major groups. There were many subgroups found in these major groups based on their genetic relatedness. These results show the application of microsatellites for studies in identification, variability, domestication and improvement of germplasm in mango.