SSR-based genetic relationship in eggplant (Solanum melongena) genotypes with varying morphological response to drought

This study assessed the genetic diversity among selected eggplant accessions with different drought responses using simple sequence repeat (SSR) markers. Twenty eggplant accessions from Turkey, China, India, Laos, Taiwan, Africa and different provinces of the Philippines were analyzed for genetic diversity. The selections include 15 Solanum melongena and 5 genotypes from 4 Solanum species (S. ferox, S. linociera, S. parkinsonii and S. nodiflorum). Eighteen polymorphic SSR markers were used to establish the genetic relationship among the 20 eggplant accessions. The selected 18 polymorphic SSR primers amplified 46 alleles with the number of alleles per primer ranging 2-4 and had an average of 2.6 alleles per primer. Null alleles were also detected in 5 SSR markers. The genetic relationship among 20 eggplant accessions was established based on UPGMA clustering. The dendrogram scale varied from 0.14 to 0.95 with a mean similarly of 0.54. At 0.70 similarity coefficient, S. melongena accessions mainly clustered together. The rest of the Solanum species (S. ferox, S. linociera, S. parkinsonii and S. nodiflorum) formed distinct single groups except for S. linociera, STL6. The highest similarity of 0.95 was obtained between S. melongena accessions while the least similarity was observed between S. nodiflorum and the rest of eggplant accessions used. The grouping of commercial varies with other landraces indicates that the commercial varieties used were similar to the landraces and that the commercial varies were bred from local materials. Cluster analysis did not distinctly separate the 20 accessions based on drought response. However, the results of the present study can be used in the selection of candidate eggplant accessions for the development of eggplant varieties for drought tolerance.