The genetics ofCochliobolus spiciferus. I. Genetic inhibition of perithecial and ascus formation

摘要

The present investigation showed that certain conidial isolates ofC. spiciferusexhibit complete mating inhibition, although the matings consisted of pairings between opposite compatibility types. Other isolates of opposite compatibility produced only sterile perithecia when mated under favorable cultural conditions. It was determined through a genetic analysis that perithecial inhibition inC. spiciferusis conditioned by the presence of the recessive allelic forms, in the homozygous condition in the fusion nucleus at either of two loci designated asI1andI2. The formation of asci in matings between strains of opposite compatibility was found to be inhibited when both isolates of the mating contain the recessive form of a third gene designated asS.The results are discussed in connection with their significance in assessing the biological relationship ofC. spiciferusto other members of the genusCochliobolusand to members of the genusCurvularia.