Results obtained from the germination of mature zygospores of Rhizopus stolonifer support the hypothesis that normal meiotic processes operate in the sexual cycle of this fungus. The mating-type allele and a second allele, sul, segregated independently. When immature zygospores were germinated no such regularity was observed, but recombinant auxotrophic genotypes were recovered indicating a predormancy meiosis. However, prototrophic recombinants were not found. Bisexual heterokaryotic strains were also recovered from immature zygospore germinations but were auxotrophic. When cultures were obtained from outgrowths of both suspensors of a single zygospore the genotypes were not always those of the respective parents. This suggests the occurrence of nuclear movement from the immature zygospore to the suspensor cells.
CutterV. M.Jr1942; Nuclear behavior in the Mucorales. 11. The Rhizopus, Phycomyces and Sporodinia patterns. Bulletin of the Torrey Botanical Club 69:592–616
EslavaA. P.,
AlvarezM. I.,
DelbrückM.1975; Meiosis in Phycomyces. Proceedings of the National Academy of sciences of the United States of America724076–4080
HawkerL.,
GoodayM.1969; Fusion, subsequent swelling and final dissolution of the apical walls of the progametangia of Rhizopus sexualis (Smith) Callen. An electron microscope study. New Phytologist 68:133–140
HockingD.1967; Zygospore initiation, development and germination in Phycomyces blakesleeanus. Transactions of the British Mycological Society 50:207–220
MagniG. E.1963; The origin of spontaneous mutations during meiosis. Proceedings of the National Academy of sciences of the United States of America50975–980