@article{mbs:/content/journal/micro/10.1099/00221287-107-1-113, author = "ELLIOTT, T. J.", title = "Comparative Sexuality in Agaricus Species", journal= "Microbiology", year = "1978", volume = "107", number = "1", pages = "113-122", doi = "https://doi.org/10.1099/00221287-107-1-113", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-107-1-113", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "The sexuality of the wild four-spored Agaricus species, A. bitorquis, A. nivescens, A. macrosporus and A. silvicola, was investigated and compared with that of the two-spored commercially cultivated mushroom, A. bisporus. For each of the wild species, 20 single spore isolates were mated in all combinations. Heterokaryosis was considered to have occurred when novel mycelial growth was apparent at the junction zones. Unifactorial heterothallism was confirmed in A. bitorquis and shown to occur in A. nivescens and A. macrosporus. There was no indication that nuclear migration occurred. Additional alleles of the mating-type factor were detected in other stocks of these three species. In A. macrosporus, heterokaryosis was enhanced by the addition of activated charcoal to the culture medium. Heterokaryosis was confirmed where possible by fruiting tests in conditions used for growing A. bisporus. Agaricus bitorquis and A. macrosporus fruited but A. nivescens did not. All matings of A. silvicola isolates were negative which, together with fruiting data, suggests that this species may be homothallic. There was no indication of heterokaryosis in interspecific matings amongst these species or with A. bisporus. The expression of sexuality in A. bitorquis, A. nivescens and A. macrosporus is contrasted with that in A. bisporus. It is suggested that A. bisporus evolved from a species of the macrosporus/nivescens type and that the constitutive heterokaryosis of A. bisporus spores may be leading to true homothallism.", }