Evaluación de la resistencia a la interacción entre Meloidogyne incognita y Fusarium oxysporum en dos especies de la sección Lasiocarpa: Solanum hirtum y Solanum sp.

Abstract

In Ecuador, cultivation of naranjilla crop (Solanum quitoense Lam.) is mainly limited by the nematode Meloidogyne incognita and the fungus Fusarium oxysporum. Interaction between these two pathogens causes low production and in some cases total loss of the crop. This research was carried out with the objective of evaluating the resistance to interaction between M. incognita and F. oxysporum in two species of the Lasiocarpa section: Solanum hirtum and Solanum sp. The study consisted of two phases: first, inoculation of M. incognita and F. oxysporum for three species on greenhouse; and, second, search for molecular markers associated with resistance. For the first phase, seedlings of approximately two months old of S. hirtum, Solanum sp. and S. quitoense (sensitive control) were inoculated with M. incognita and F. oxysporum. A randomized complete block design (DBCA) in a 3x3 factorial arrangement with five repetitions was used. For the second phase, molecular markers SSR and RGAs associated with resistance were analyzed in the Molecular Biology Laboratory of the University of Cuenca for parents and a segregating population of S. hirtum x S. quitoense cross. The results showed indicate that S. hirtum and Solanum sp. obtained the best performances in terms of the variables accumulated biomass, height, stem diameter, degree of discoloration and degree of severity of wilting, since they presented significant differences compared to the sensitive control S. quitoense. Two SSR markers and four RGAs markers based on resistance genes showed polymorphism. They amplified only in S. hirtum, and presented polymorphism in the segregating population of the S. hirtum x S. quitoense cross.