POLYPLOIDY IN THE BASIDIOMYCETE CYATHUS STERCOREUS

Chromosome analysis of the basidiomycete Cyathus stercoreus (Nidulariaceae) reveals that certain chromosomes of the haploid complement structurally resemble one another. These like chromosomes exhibit with high frequency a tendency to form quadrivalents or to show secondary association at diplotene and diakinesis of meiosis, suggesting some degree of homology. This indicates that C. stercoreus is a tetraploid species. It is suggested that the polyploidy of the present species may have resulted from allotetraploidy involving species which may have been evolved from a single ancestor.