Reaction of Capsicum peppers commercialized in the Federal District to bacterial wilt

Reação à murcha bacteriana de pimentas Capsicum comercializadas na região do Distrito Federal

ABSTRACT

In Brazil, the bacterial pathogens Ralstonia solanacearum and R. pseudosolanacearum cause substantial losses by inducing bacterial wilt on several solanaceous crops; R. pseudosolanacearum is the main species associated with peppers (Capsicum sp.). To verify the bacterial wilt reaction on Capsicum peppers commercialized in the Federal District (DF), fruits of several genotypes within this genus were collected from six different fairs distributed in the satellite cities of Gama, Sobradinho and Guará. Seedlings with four true leaves derived from seeds extracted from such fruits were root inoculated with 10⁸ CFU/mL with a representative isolate of R. pseudosolanacearum (race 1, biovar 3, phylotype I, sequevar 18). The evaluated species were: Capsicum frutescens (‘pimenta-malagueta’), Capsicum baccatum var. pendulum (‘pimenta-dedo-de-moça’) and C. chinense (‘pimenta-de-bode’ red and yellow, ‘pimenta-cumarí-do-Pará’, ‘pimenta-biquinho’, ‘pimenta-habanero’ and ‘pimenta-de-cheiro’). Not all species were found in all six fairs. The reaction to bacterial wilt was variable and species-dependent. From 26 evaluated genotypes, none presented an immune-like response, 10 were considered resistant and 16 susceptible based on wilt incidence (Scott-Knott, 5%). Four Capsicum baccatum accesses were positioned in the resistant group, whereas 14 out of 18 of C. chinense were susceptible. Capsicum frutescens showed variable reactions. These results contribute to indicate cultivation of specific groups of pepper according to the presence of the pathogen in the soil.

Keywords:
Ralstonia solanacearum; Ralstonia pseudosolanacearum; Capsicum sp.; Capsicum chinense; Capsicum baccatum var. pendulum; Capsicum frutescens; disease resistance