Genetic Assessment in the Andean Tropical Fruits Solanum quitoense Lam. and S. betaceum Cav.: Efforts Towards a Molecular Breeding Approach

<i>Solanum quitoense</i> and <i>S. betaceum</i> called, respectively, naranjilla and tomate de arbol, are both tropical Andean fruits of growing interest in the region. Microsatellite primers (SSRs) identified by NGS technology in both species were screened for the development of SSR marker technology. In <i>S. quitoense</i>, it was found that 41 primers were successfully transferred to six Lasiocarpa closely related species. Using multiplex primer combinations with the M13-Tailing technology in the DNA analyzer LI-COR 4300s, the variability of these primers in seven <i>S. quitoense</i> landraces was characterized. This SSR survey confirmed the narrow genetic base of <i>S. quitoense</i> cultivars with the polymorphism of 14 SSR markers. Moreover, transferability rates and genetic diversity analysis revealed a closer genetic relationship between the species <i>S. candidum</i> and <i>S. hirtum</i> among the Lasiocarpa germplasm screened. On the other hand, 110 SSR primers were screened in four cultivars, segregating plants and wild-related accessions of <i>S. betaceum</i>. Polymorphisms for only eight SSR primers were found but including the wild relative <i>S. unilobum</i>; in <i>S. betaceum</i>, no SSR showed polymorphism confirming the high genetic homogeneity of the cultivars. The results of this study are potentially useful for <i>S.quitoense</i> and <i>S. betaceum</i> genomics, providing an initial set of SSR markers for molecular characterization in <i>S. quitoense</i> germplasm and perspectives for <i>S. betaceum</i>.