Effectiveness of SSR molecular markers in evaluating the phylogenetic relationships among eight Actinidia species

The aim of the present study is to evaluate a set of microsatellites and their effectiveness in determining the phylogenetic relationships among Actinidia species. A set of 14 genotypes belonging to eight Actinidia species were subjected to PCR using SSRs as molecular markers. The PCR products were analyzed on denaturing polyacrylamide gels. The discriminating ability of SSRs was based on the number of alleles and the indices DI, I and PIC. All SSR primer pairs were polymorphic and identified a total number of 61 alleles corresponding to an average of 7.8 alleles per locus. Data showed that the di-nucleotide microsatellites were more polymorphic, than the tri-nucleotide and penta-nucleotide, and were more efficient in establishing genetic similarities. The genetic similarity of the genotypes calculated with Jaccard and/or Dice similarity coefficients varied from 0.100 to 0.579, indicating a broad genetic base for the genetic material tested. Both similarity matrices clustered either with UPGMA or NJ, produced similar topology with minor clustering differences among genotypes. Thus, the eight species were clustered in two main groups and each main group in two subgroups. Data showed a close genetic relationship among Actinidia chinensis and Actinidia deliciosa species. The same conclusions were, also, drawn using the principal coordinate analysis.