Fruiting and Genetic Analysis of Heterobasidion annosum

Abstract
Several methods for fruiting H. annosum are presented. The methods are simple, reproducible, and can be applied to heterokaryotic mycelia isolated from nature as well as the mycelia resulting from crosses of homokaryotic strains. Methods for mutagenesis and recovery of auxotrophic and morphological mutants are discussed. Instances of fruiting in common-A heterokaryons and in homokaryons are analyzed. The importance of meeting genetic criteria for successful fruiting is discussed.