Assessment of diversity and population structure of mango (Mangifera indica L.) germplasm based on microsatellite (SSR) markers

Abstract

The assessment of genetic diversity is essential for the conservation and breeding purposes. This study aimed to assess and evaluate the genetic diversity of 116 accessions of mango (Mangifera indica) germplasm using microsatellite markers. The DNA was extracted from young fresh leaf before genotyping using microsatellites to determine the allele size. The analysis of 20 polymorphic microsatellite markers revealed a total of 122 alleles ranging from two (MiIIHR10, MiIIHR21, and MiIIHR25) to 11 alleles per locus (MiIIHR28 and MiIIHR30) with an average of 6.1. The mean polymorphic information content (PIC) value was 0.4585 which ranged between 0.0081 (MiIIHR10) to 0.9573 (MiIIHR28). The UPGMA dendrogram indicated that the accessions were divided into two major clusters, which were divided into several sub-clusters based on their genetic distance matrix values. Some accessions were highly similar to each other, probably due to the duplication of collected accessions or insufficient microsatellite markers to differentiate them. The analysis of the population structure of the individuals also showed two subpopulations, suggesting that the accessions could be separated into two groups, which supported the generated dendrogram. The findings of this study facilitate improved conservation management of the germplasm and help to find strategies for future breeding activities.