Efecto del ácido salicílico en la inducción de la resistencia en tomate de árbol (Solanum betaceum) a la antracnosis y caracterización molecular

Abstract

The tree tomato (Solanum betaceum) is a species of Andean origin, which has great potential due to its organoleptic characteristics. However, it is very susceptible to the presence of anthracnose whose causal agent belongs to the complex Colletotrichum acutatum. This research was conducted in the field and laboratory. In the field, the effect of salicylic acid (AS) in tree tomato was evaluated against anthracnose. To fulfill this objective, the effect of salicylic acid was evaluated in three concentrations (0.1, 0.2, and 0.4 mM). The application was made directly in the crop. For this, a completely randomized block design with 10 repetitions and a control was used. It was also molecularly characterized 16 strains of Colletotrichum acutatum complex from Azuay and Loja provinces through multilocus analysis by PCR, based on primers defined in actin genes, β-tubulin, and glyceraldehyde 3-phosphate dehydrogenase. The following results were obtained for the effect of AS in resistance induction: 0.2 mM concentration showed significant results when anthracnose severity in fruits was reduced; 0.1 mM concentration had significant effects when anthracnose severity in leaves was reduced in front of control plants and anthracnose incidence in leaves. Besides, the 0.4 mM concentration showed a higher leaf and fruit shedding with contaminated tissue as a defense mechanism against the disease compared to the control. Regarding the molecular analysis by multilocus, it was demonstrated that the species responsible for anthracnose in tree tomato is Colletotrichum tamarilloi, which belongs to the Colletotrichum acutatum complex.