Analysis of genetic variation among red flesh apple genotypes using microsatellite markers and polymorphism of MYB10 gene

Red flesh apple is one of the Iranian apple genotypes containing high level of anthocyanin in the cortex and flesh of fruit which causes red color in fruits. In order to assess genetic diversity of these native red flesh genotypes, 20 genotypes from red and white flesh fruits were selected and evaluated using 11 SSR primer pairs among which seven pairs showed polymorphism and a total of 56 alleles were generated. The number of alleles per locus varied from 3 to 11 with an average of 8 and also the average number of effective alleles was 5.74 per SSR locus. Furthermore, the averages of expected and observed heterozygosity were 0.6 and 0.77, respectively. The cluster analysis based on Dice similarity coefficient and UPGMA method distinguished genotypes into 7 groups. According to the dendrogram, no significant relation between classification and geographical origin was observed therefore those genotypes originating from the same area classified into different groups. As MYB10 gene is responsible for color of red flesh apple, we used the information about polymorphism in the promoter of the gene from all the studied genotypes. Considering self-incompatibility of apple, it seems that crossing between heterozygote red flesh genotypes with MYB10 and white fleshes have resulted in generation of the red and white flesh apples that are closely related.