Notes on Mucorales—I. Observations on Absidia

An account is given of species of Absidia maintained in the CBS collection. Cultures were studied on the basis of morphology, temperature relations and mating results. Synonymy is concluded for A. atrospora, A. griseola, and A. hyalospora with A. blakesleeana; A. hesseltinei with A. corymbifera. Mating activity was strong in the subgenus Mycocladus, weak or absent in the subgenus Absidia, under the test condition. A key to the species is included

Various aspects of the mating system in Mucorales

Several aspects of the sexuality in Mucorales are discussed. It is stated that neither heterothallism nor homothallism are absolute conditions and that a continuum exists between zygospores and azygospores. Mating type switching as known in ascomycetous yeasts would explain several up to now inexplicable phenomena

Comparison of Zygospore ornamentation in intra- and interspecific matings in some related species of mucor and Backusella

Zygospores resulting from intraspecific matings of Mucor amphibiorum, M. inaequisporus, M. indicus, M. recurvus, M. variosporus, Backusella circina, and B. lamprospora are compared with azygospores (zygospores) formed in matings of Mucor amphibiorum strain CBS 764.74 and strains of the other species by means of scanning electron microscopy. In general zygospores in interspecific matings cease to develop at an earlier stage than those of intraspecific matings. No proof could be obtained for our hypothesis that M. amphibiorum strain CBS 764.74 merely initiated a process of azygospore formation