DISCRIMINATING SYNERGISM AND ANTAGONISM OF SPORES WITHIN SPECIES OF PHYTOPATHOGENIC FUNGI

Synergism and antagonism of spores of phytopathogenic fungi can be det ected by comparison of the changes in the infection probabilities at d ifferent inoculum densities. In this paper, we describe a model, devel oped from the formula of the multiple infection transformation and pro bability theory, that can be used to discriminate the synergism and an tagonism of spores. A function was derived that allows the easy evalua tion of synergism and antagonism. The model was used to analyze the ex perimental data of Puccinia striiformis spores and winter wheat. The d efinition of antagonism is broader than that used by Vanderplank.