Linkosia

Fungalpedia – Note 2826, Linkosia

Linkosia. A. Hern.-Gut. & B. Sutton.

Citation when using this data: Wenping Wu et al. 2022 – Fungalpedia.

Index Fungorum, Facesoffungi, MycoBank, GenBank

Classification:, Incertae sedis, Incertae sedis, Incertae sedis, Incertae sedis, Pezizomycotina, Ascomycota, Fungi

Colonies effuse, hypophyllous, brown. Mycelium superficial, composed of septate, brown to dark brown hyphae. Teleomorph: Unknown. Anamorph: Conidiophores absent. Conidiogenous cells discrete, determinate, lageniform, ampulliform, subcylindrical, solitary or aggregated at the base, short, simple, truncate at the apex. Conidial ontogeny holoblastic, one locus per conidiogenous cell, solitary conidia, delimitated by one septum, maturation by diffuse wall-building, secession schizolytic, no proliferation. Conidia holoblastic, straight or slightly curved, narrowly obclavate to obclavate-rostrate, filiform, conical-truncate at the base, distoseptate, pale brown to brown, smooth, subhyaline at the apex (Adapted from Wu and Zhuang 2005).

Ecology/Substrate/Host: Saprobes on decaying plant material, and commonly found on dead culm of bamboo.

Known distribution: Broadly distribution, especially from subtropical and tropical areas.

Description and illustration: Hernández-Gutiérrez and Sutton (1997); Wu and Zhuang (2005); Seifert et al. (2011).

Notes: Linkosia differs from Sporidesmium Link and the other segregated genera in that the conidiophores are absent, the conidiogenous cells are directly formed from superficial hyphae, and the conidia are distoseptate 25 (Subramanian 1992; Hernández-Gutiérrez and Sutton, 1997). Stanjehughesia and Janetia are the two related genera to Linkosia in many respects such as absence of conidiophores, lageniform conidiogenous cells directly formed from superficial mycelium and obclavate conidia. However, the conidia in these two genera are euseptate (only one species in Janetia, J. longispora is with distoseptate conidia). In addition, all members of the genus Janetia superficially grow on leaves of various plant species (Ellis 1976; Hughes 1983; Hernández-Gutiérrez and Mena Portales 1996; Goh and Hyde 1996a, b, c). A total of 12 species are known in the genus Linkosia and they can be distinguished by shape, size and septation of conidia (Hernández-Gutiérrez and Sutton 1997; Castañeda-Ruíz et al. 2000; Wu and Zhuang 2005; Zhang et al. 2009; Ma et al. 2011b; Almeida et al. 2014; Delgado 2014; Conceição

et al. 2016; Xu et al. 2017).

The ITS and LSU sequences were obtained from four species, L. filiformia, Linkosia gelatinosa, L. multiseptum, L. obclavata, and L. rostrata, the phylogenetic analysis showed that these four species with distoseptate conidia, Linkosia gelatinosa, L. filiformia, L. multiseptum and L. rostrata, were clustered together, while one species L. obclavata, with euseptate conidia, is phylogenetically closer to Stanjehughesia. No DNA sequence is available from the type species L. coccothrinacis, and assignment of the genus to Chaetosphaeriaceae needs to be further confirmed when the DNA sequence data will be available from fresh collection. Ten species of Linkosia, including four new species, are known from China and documented here (Wu and Zhuang 2005; Zhang et al. 2009; Ma 2011; Xu et al. 2017).