“Determinación de la resistencia a Meloidogyne incognita, en tres especies de la sección Lasiocarpa: Solanum quitoense, Solanum hirtum y Solanum sp.”

Abstract

The naranjilla crop has a great potential in Ecuador, due to its excellent organoleptic characteristics. Nevertheless, the crop has a high susceptibility to attack of nematode Meloydogyne incognita, sometimes occasioning the total loss of crop. This research was carried out under greenhouse and the objectives were: determine the resistance to Meloidogyne incognita, in three species of the Lasiocarpa section: S. quitoense, S. hirtum and Solanum sp; and, find RGAs and SSR molecular markers associated with resistance. For phenotypic analysis, a completely randomized design with five repetitions was used, and for molecular analysis the polymorphism based on absence or presence of amplification products was considered. Nematode inoculum was extracted from roots infected with naranjilla. For molecular analyzes, we used RGAs and SSR primers defined on homology regions for crop resistance genes previously identified. We found that for variables: accumulated biomass, population increase, incidence, index of knotty and severity, results showed highly significant differences between S. hirtum and Solanum sp. with respect to susceptible specie (S. quitoense) at 80 days of evaluation. Regarding the molecular markers, we found two pairs of primers that amplified in S. hirtum and S. quitoense: an RGA defined on an LRR domain and an SSR defined in pepper. No amplifications were obtained in Solanum sp. Furthermore, these primers were found to be polymorphic in the segregating population between S. quitoense and S. hirtum.