Some Cultural and Genetic Aspects of a New Heterothallic Sordaria

Abstract

Fields, William G., and James Maniotis. (Wayne State U., Detroit, Mich.) Some cultural and genetic aspects of a new heterothallic Sordaria. Amer. Jour. Bot. 50(1): 80–85. lllus. 1963.— Sordaria heterothallis sp. nov., isolated from rabbit dung collected in Austin, Texas, is characterized as a spermatium‐prcducing, hcterothallic Sordaria with carbonous stromatic walls. Spermatia may germinate, but their low frequency of germination suggests their role in asexual reproduction is minor. The fungus was determined to be biotin‐ and thiamine‐deficient. A single pair of factors about 1.9 units from the centromere governs compatibility. Ordered tetrad analyses indicates regular segregation of factors for ascospore germination, the production of aerial mycelium and pigmentation. Intra‐ and intergeneric reactions stimulating protoperithecial production occurs between Sordaria heterothallis and the related species Sordaria brevicollis and Gelasinospora atilosleira.

Reproductive Biology of Fungi

“…Typical examples of Ascomycetes with bipolar mating types are Neurospora crassa. N. sitophilla (Whitehouse 1949b), Sordaria brevicollis (Olive and Fantini 1961), S. heterothallis (Fields and Maniotis 1963), S. sclerogenia (Fields and Grear 1966), Ascobolus stercorarius (Bistis and Raper 1963), Aspergillus heterothallicus (Raper and Fennel 1965) and species of Chaetomium (Seth 1967). In some bipolar heterothallic fungi an interesting mechanism operates during spore formation, whereby two nuclei of opposite mating types are incorporated in each spore.…”

Genetic Evidence for Hybridization in an Interspecific Cross in the Genus Sordaria

“…The germinable ascospores germinated without any of the pre-germination activation that was mandatory for Sordaria heterothallis and S. thermophila. The ascospores of S. heterothallis are only known to germinate when incubated on a medium containing 7 % sodium acetate (Fields & Maniotis, 1963), and those of S. thermophila require a 2-hr heat shock treatment and incubation on a medium containing 0.55 % ammonium acetate (Lewis, 1969).…”