Microsatellite markers analysis for evaluation of genetic variation in mango genotypes

The study was under taken to evaluate the genetic variation in seven mango genotypes, namely, Amrapali, Dushehari, Janardan Pasand, Neelam, Pusa Arunima, Sensation and Tommy Atkins using SSR markers. At first, forty-two microsatellite markers were screened in mango genotypes for getting polymorphic SSR markers then polymorphic SSR markers were utilized for further analysis. Out of 42 primer pairs screened, 13 primer pairs namely LMMA2, LMMA3, LMMA4, LMMA7, LMMA8, LMMA9, LMMA11, LMMA12, LMMA16 and ESTD1, ESTD2, ESTD9 and ESTD10) were found polymorphic and rest of primers got monomorphic status. These 13 polymorphic markers were generated 43 alleles varied from 2 to 5 with an average of 3.30 alleles per locus among the mango genotype tested. The major allele frequency was varied from 0.36 to 0.86 for the locus ESTD9 and LMMA4, respectively. Mean major allele frequency was 0.60 for all the polymorphic loci. The observed heterozygosity (Ho) for individual loci ranged from 0.14 (ESTD2) to 0.86 (LMMA16), with an average of 0.44 over all loci. Whereas, gene diversity varied from 0.24 (LMMA4) to 0.74 (ESTD9), with an average of 0.53.The PIC value ranged from 0.21 (LMMA4) to 0.70 (ESTD9) with an average of 0.47. The microsatellite markers study helped in identification of genetic distance among mango genotypes. Dissimilarity matrix suggested a clear separation between Indigenous and exotic genotypes.