Genetic Basis of Biological Species in Heterobasidion annosum: Mendelian Determinants

Publisher Website
Google Scholar
Abstract
Mating experiments were conducted to determine the existence of biological species (intersterility groups) of the root-rotting fungus, Heterobasidion annosum (Basidiomycotina, Homobasidiomycetes) in North America. Initial screening utilized tester strains from Finland and identified represntatives of both the "S" and "P" intersterility groups. Pairings of North American "S" group strains with North American "P" group strains, however, revealed a significant degree of interfertility between the two groups. The data indicate that intersterility is under the regulation of simple, Mendelian determinants. These genes are distinct and separable from the mating-type (incompatibility) locus. The data suggest that H. annosum is undergoing speciation and may make an attractive model system for the study of evolutionary processes in higher fungi.