Abstract

REYES-TENA, Alfredo et al. Morphological characterization of Phytophthora capsici isolates from Jalisco and Michoacán, Mexico. Rev. mex. fitopatol [online]. 2021, vol.39, n.1, pp.75-93.  Epub May 07, 2021. ISSN 2007-8080.  https://doi.org/10.18781/r.mex.fit.2007-5.

Phytophthora capsici is the main phytopathogen of the chili pepper crop (Capsicum annuum) and diverse commercial plants in Mexico. The limited knowledge of farmers on the presence of this pathogen in cropping areas makes it difficult to prevent and manage the disease. In order to identify and morphologically characterize isolates obtained from cucurbits and solanaceous crops with “wilt” symptoms, in Jalisco and Michoacán, Mexico, samples were collected during 2016 and 2017. The 41 P. capsici isolates obtained from diseased plants were analyzed by comparative morphology based on sexual and asexual characteristics. Were characterized 33 isolates from the C. annuum crop, six from C. pepo and two S. lycopersicum. Most isolates showed typical characteristics of P. capsici, whereas only one isolate showed terminal, globose chlamydospores (isolated from Queréndaro, Mich.). Forty heterothallic isolates were registered and only one homothallic isolate was reported. The pathogenicity of seven isolates was tested, therefore according to the results obtained, P. capsici is the main causal agent of wilt for these isolates and for seven more analyzed in a previous study, the remaining 27 are associated with the disease. Calling for the development of a strategy for integrated management of this pathogen in the Jalisco and Michoacán production areas.

Keywords : Capsicum; Cucurbita; isolation; chili wilt; diagnosis.