Morphological, pathogenic and genetic diversity of Botrytis cinerea Pers. in blackberry cultivations in Colombia

Abstract The Andean blackberry (Rubus glaucus Benth) is one of the most important fruits with the greatest commercial projection in Colombia. The factors that most affect its production are the attack of diseases and the scarce information about its control. One of the most limiting diseases of the crop is the gray mold, produced by the fungus Botrytis cinerea. This research presents the diversity of B. cinerea isolates from fields of andean blackberry in Colombia, based on the morphological, pathogenic and genetic characteristics allowing broadening the knowledge of the phytopathogen for subsequent management measures. Andean blackberry fruits were collected with characteristic symptoms of gray mold in farms located in eight producing areas of Colombian Andean region. A total of 50 samples were analyzed finding two types of growth, miceliar and sclerocial, differences in the layout and size of the sclerotia, as well as differences in the daily growth of the mycelium. Regarding genetic characterization with microsatellite markers, it was shown that genetic diversity is concentrated within populations and that there is a tendency to group by geographical origin. With the pathogenicity tests, the two most pathogenic isolates were selected and it was found that, although the four possible genotypes were found with the transposable elements (Vacuma, Transposa, Boty, Flipper), none of them presented high resistance to the fungicide fenhexamide.