Hybridization studies within the genus Schwanniomyces Klöcker.

Hybridization studies based on the prototrophic selection technique involving the use of auxotrophic mutants of seven Schwanniomyces strains are reported. Recombinant formation was not detected in any of the 87 experiments comprising both intrastrain and interstrain crosses of strains previously identified as S. alluvius, S. castellii, S. occidentalis, and S. persoonii.