THE BEHAVIOR OF THE FUNGUS Colletotrichum gossypii South Var. cephalosporoides Costa IN SUBSTRATE CONTAINING DIFFERENT SOURCES OF NITROGEN

Abstract

In this experiment, the effect of different nitrogenous substances on the mycelium growth, sporulation and morphological aspects of the colonies of the fungus Colletotrichum gossypii  South Var. cephalosporoides Costa planted in a solid substrate were observed. A synthetic substrate was used as a basic medium, and to this was added peptone metionine, asparagine, sodium nitrate or ammonium salicylate, according to the treatment. The control (group) received no nitrogen whatsover. It was concluded that peptone was the best treatment for sporulation and mycelium growth, and that the next best was asparagine which was helpfull in inducing sporulation. Ammonium salicylate inhibited the vegetative growth and the sporulation of the fungus. For the production of inocule, over a short period of time, the use of peptone as source of nitrogen is recommended. Differences in the pigmentation, edges, and density of the colonies were observed. Sporulation, though abundant in the substrate containing peptone and asparagine, ocurred in the form of localized masses of conidia in the first and as dispersed conidia in the second.