cpSSR marker based DNA fingerprinting and diversity assessment of mango genotypes

Abstract

Germplasm characterization is a pre-requisite for their conservation and utilization in breeding programme. We used cpSSR markers for the first time to identify a set of polymorphic microsatellite loci and analysis of genetic diversity within mango genotypes. The present study was aimed to assess the intraspecific relationships among 28 diverse mango genotypes using uniparental and haploid chloroplast SSR (cpSSR) marker. A total of 27 alleles were identified with an average of 1.5 allele per locus. Seven out of 18 primer pairs showed polymorphic bands with a number of alleles ranging from one to three. The genotypes studied revealed significant levels of cpDNA genetic diversity. Shannon diversity index and gene diversity varied, from 0.07-0.32 and 0.34-0.95 respectively. Marker index and resolving power were ranged 0.04- 2.14 and 0.07-1.71. cpSSR markers are suitable for characterization and assessment across diverse mango genotypes and there is small difference in the genetic diversity with the species. Results indicated that two mango cultivars (Sukul and Himsagar) were found to be far distant of the genetic relationship from the other cultivars. Analysis of overall diversity of mango genotypes revealed the less intraspecies diversity (40%). This low intraspecific diversity is due to high degree of gene flow in population through random mating without barrier. The information of this work will be useful for selection and more efficient utilization of mango germplasm in breeding programs in the future.