THE BEHAVIOR OF Colletotrichum gossypii SOUTH. Var. cephalosporioides COSTA IN SUBSTRATE WITH DIFFERENT CARBON SOURCES

Abstract

In this experiment, the behavior of Colletotrichum gossypii South. var. cephalosporioides Costa, in a solid substrate containing different sources of carbon, was attempted to be determined. The vegetative growth, intensity of sporulation, size of the conidia, were measured and the morphological characteristics of the colony were described. A synthetic substrate was used as the basic medium, and to this, the source of carbon, according to the treatment (maltose, dextrose, lactose, starch, saccharose and galactose), was added. It was concluded that the doxtrose produced a greater vegetative growth in the colonies, but the starch produced greater intensity of sporulation. The galactose seemed to have exercised a harmfull effect on the development of the fungus, stimulating the formation of small colonies, atypical and the few conidia produced exhibited shorter length than the conidia formed in the other tested substances. There was no correlation between the intensity of sporulation and the size of conidia, nor between the vegetative growth and intensity of sporulation. The composition of the substrate affected profoundly the color, the shape, the aspect, the periphery and the topography of the colony.