Caracterização fisiológica, cultural e patogênica de diferentes Isolados de Lasiodiplodia theobromae

Abstract

Lasiodiplodia theobromae is responsible for diseases in several cultivated plants, causing significant losses in production, particularly among fruit trees in the Brazilian Northeast. Basic studies on this fungus are necessary to understand better the pathogen-host interactions and to trace control strategies. This work aimed to characterize eight isolates of L. theobromae from different hosts, accessing the mycelial growth, pycnidium production and fertility, morphological aspects of the colonies and pathogenicity. The isolates varied in all the characteristics studied. The culture medium of oatmeal agar provided best pycnidium production and fertility, with the isolate obtained from mango and passion fruit standing out. The culture medium of carrot agar did not provide pycnidium production. With relation to mycelial growth, V-8 juice medium was the culture medium which provided fastest mycelial growth. Coloration of the colony varied across a wide range, with white-gray coloration prevailing. As to the formation of pycnidia, it was verified that most of the isolates formed pycnidia. Assays evaluating pathogenicity by cross inoculation revealed that all isolates were pathogenic against all tested host plants.