Volume 19 Part 1 Article 140
Title: Asexual spores as means for de-dikaryotization of mycelia
Author: Weeradej Khonsuntia, Susanna Badalyan, Shanta Subba, Mandira Sen, Ursula Kües
Mitospores have been observed on mycelia of various Agaricomycetes but usually have found only limited interest in the past. A general believe was that mitospores are more often produced on monokaryons than on dikaryons [1,2]. A recent literature account on multiple species of Agaricomycetes comes to a different conclusion, i.e. that mitospore production on dikaryons might be much more widespread on dikaryons than so far thought . Mitotic spores can be broadly distinguished into arthroconidia (oidia), blastoconidia and chlamydospores. The latter are thick-walled and produced within aging hyphae and serve for dormancy. Arthroconidia and blastoconidia in contrast might have functions in fungal distribution and in mycelial spermatisation. Such spores when formed on monokaryons can naturally only germinate into monokaryons. Mitospores on dikaryons might either be homokaryotic or heterokaryotic although the nuclear status of the spores is often still unknown. Here we will give a summary of species where the nuclear status of spores formed on dikaryons is known (Table 1). Species differ in whether only homokaryotic spores are formed on dikaryons, or only heterokaryotic spores or percentages of both. Homokaryotic spores with only one type of haploid nuclei can be of impacts in genetic structures of populations when they mate with new compatible partners . Coprinopsis cinerea is a species that forms abundant uninucleate oidia on monokaryotic mycelia and lower numbers of uninucleate oidia upon light induction on the dikaryon. Oidia are also formed on dikaryons of other Coprinopsis species and of Coprinellus species [3,5]. We now analyze the nuclear status of these spores formed on dikaryons, their numbers of production and their germination abilities.