Genetic and Environmental Aspects of Fruiting in Schizophyllum Commune Fr.

Abstract

SUMMARY An extensive study of fruiting in a large, world-wide sample of Schisophyllum has revealed genetic background as the most critical factor in determining the occurrence and time of fruiting and the form of the fruiting bodies. In a sample of 116 homokaryotic mycelia cross-mated in all combinations, fruiting occurred in 80% of the resulting 6546 dikaryons. The occurrence and time of fruiting, however, were not random: good fruiting and poor fruiting were conspicuously correlated with specific component strains. Detailed analysis of a smaller sample of 80 strains permitted a quantitative determination of fruiting competence and the classification of individual strains in respect to the character. Fruiting competence is inherited as a quantitative character; in dikaryotic mycelia, poor fruiting potential is masked by high fruiting competence. Five fruiting abnormalities, each genetically determined, have been analyzed and may be characterized as follows: The effects of light, nutrient, and other environmental factors have been again confirmed, but no restoration to normal fruiting in genetically inadequate stocks has been achieved through alterations of external factors.