Variation in pathogenicity among and within populations of the fungus Phomopsis subordinaria infecting Plantago lanceolata

Abstract

The expression of the pathogen appeared to be quantitative rather than qualitative in character, which suggests polygenic inheritance of host susceptibility. Significant statistical interaction between pathogen and host pointed to some degree of physiological specialization between them. None of the individual host-pathogen combinations contributed significantly to the interaction. Environmental factors (in particular weevils that spread the disease) are important for the development of the disease. The pathogen varied in pathogenicity in the field, even among scapes within an individual host plant. -from Authors