title: Understanding lichenicolous heterobasidiomycetes: new taxa and reproductive innovations in Tremella s.l.
abstract: Four new lichenicolous Tremella species are described and characterized morphologically and molecularly. Tremella celata grows on Ramalina fraxinea, inducing the formation of inconspicuous galls, and having hyphae with incomplete clamps. Tremella endosporogena develops intrahymenially in the apothecia of Lecanora carpinea, having single-celled basidia and clampless hyphae. Tremella diederichiana is the name proposed for a species micromorphologically close to T. christiansenii but inducing the formation of small, pale galls on the thallus and apothecia of Lecidea aff. erythrophaea Tremella variae grows on Lecanora varia thallus, instead of on the apothecia, as do the other known Tremella species parasitizing Lecanora s.l. Phylogenetic relationships and host specificity of these species are investigated and compared with other taxa that show morphological resemblances, phylogenetic affinities or similar hosts. The formation of mitotic conidia inside old basidia (endospores), which is a poorly known reproductive strategy in the Basidiomycota, is also a distinctive character of Tremella endosporogena A discussion on the reproductive role and systematic implications of endospores is included.
authors.affiliation: Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, E-28040 Madrid, Spain jcsenoret@gmail.com.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Zamora
authors.affiliation: Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, E-28933 Móstoles, Spain.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Millanes
authors.affiliation: Department of Botany, Swedish Museum of Natural History, P.O. Box 50007, SE-10405 Stockholm, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Wedin
authors.affiliation: Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, E-28040 Madrid, Spain.
authors.forename: Víctor J
authors.initials: VJ
authors.lastname: Rico
authors.affiliation: Real Jardín Botánico, CSIC, E-28104 Madrid, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Pérez-Ortega
mesh_terms: D001487:Basidiomycota / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D008011:Lichens / Q000382:microbiology*; D010802:Phylogeny; D013045:Species Specificity
keywords: ITS; Tremellomycetes; endospores; host specificity; rDNA