Pyxidiophora

Fungalpedia – Note 3190, Pyxidiophora

Citation when using this data: Wenping Wu & Yongzhao Diao. 2023 – Fungalpedia.

Index Fungorum, Facesoffungi, MycoBank, GenBank

Classification: Pyxidiophoraceae, Pyxidiophorales, Laboulbeniomycetidae, Laboulbeniomycetes, Pezizomycotina, Ascomycota, Fungi

= Acariniola T. Majewski & J. Wiśn., Acta Mycologica, Warszawa 14: 7, 1978.

= Amphoropsis Speg., Anal. Soc. cient. argent. 85(3): 312, 1918.

= Ascolanthanus Cailleux, C. r. hebd. Séanc. Acad. Sci., Paris, sér. III. 265: 1473, 1967.

= Copranophilus Speg., Anal. Mus. nac. B. Aires, Ser. 3, 12: 410, 1909.

= Eleutherosphaera Grove, J. Bot., Lond. 45: 171, 1907= Endosporella Thaxt., Bot. Gaz. 69: 16, 1920.

= Entomocosma Speg., Anal. Soc. cient. argent. 85(3): 315, 1918.

= Mycorhynchus Sacc. & D. Sacc., Syll. Fung. (Abellini) 18: 418, 1906

= Myriapodophila Speg., Anal. Soc. cient. argent. 85(3): 313, 1918.

= Rhynchomyces Sacc. & Marchal, in Marchal, Bull. Soc. R. Bot. Belg. 24(1): 60, 1885.

= Rhynchonectria Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 111: 1023, 1902.

= Thaxteriola Speg., Anal. Soc. cient. argent. 85(3): 314, 1918.

= Treleasia Speg., Revista Fac. Agron. Univ. nac. La Plata 2(19): 235, 1896.

Coprophilous or saprophytic on other substrates, rarely mycoparasitic. Anamorph: Stroma absent. Setae absent. Conidiophores macronematous, mononematous, arising laterally from aerial hyphae, scattered, solitary or aggregated, hyaline, septate, rarely branched, smooth. Conidiogenous cells integrated, terminal, determinate, phialidic, erect, straight or slightly curved, hyaline to very pale brown, smooth, transition from venter to collarette gradual, venter subcylindrical, collarette cylindrica. Conidia endogenous, catenate, hyaline, cylindrical, smooth-walled, truncate at each end, aseptate, first formed conidia subglobose or ellipsoid. Teleomorph: See Lundqvist (1980).

Ecology/substrate/host: Mostly saprotropic, growing on dung or decaying vegetable material, associated with insect, mites and nematode, but a few (P. asterophora, P. lundqvistii, P. spinulorostrata) are mycoparasites (Lundqvist 1980; Haelewaters et al. 2021a, b; Doveri and Coué 2016).

Geographical distribution: Widely distributed (Marchael 1885; Lundqvist 1980; Haelewaters et al. 2021a, b). Description and illustration: Lundqvist (1980).

Notes: Taxonomy of Pyxidiophora were discussed by Breton and Faurel (1967), Hawksworth and Webster (1977), Lundqvist (1980), Blackwell et al. (1986, 1989) and Haelewaters et al. (2021a, b, 2022). Lundqvist (1980) considered Mycorhynchus, Treleasia, Copranophilus, Ascolanthanus, and Acariniola to be congeneric with Pyxidiophora and recognized about twenty species in the genus. Since then, a number of new species have been added to the genus (Hawksworth and Webster 1977; Barrasa and Moreno 1982; Blackwell et al. 1986; Kirschner 2003; Haelewaaters et al. 2021b). Pyxidiophora differs from the only other genus Mycorhynchidium (sexually typified genus, without known anamorph) of the family in having long beaked perithecioid rather than cleistothecioid ascomata.

Pyxidiophora was placed under Hypocreales (Breton and Faurel 1967; Rogerson 1970; Müller and von Arx 1973; Hawksworth and Webster 1977; Webster and Hawksworth 1986). Arnold (1971), however, considered the genus distinct from other hypocrealean genera and erected the monotypic family Pyxidiophoraceae. Lundqvist (1980) followed this arrangement and emended the family to include the cleistothecial genus Mycorhynchidium (Malloch and Cain 1971). Lundqvist (1980) was the first to recognize the similarity between ascospores of Pyxidiophora and the thalli of Acariniola spp. and Thaxteriola spp. On mites associated with bark beetles and placed these species in Pyxidiophora. The hypophoretic spores of Pyxidiophora often possess an attachment apparatus (a dark, adhesive, apical or subapical area) which allows them to be carried by the mites linked to these insects (Lundqvist 1980; Blackwell et al. 1988; Blackwell & Malloch 1989; Blackwell 1994; Weir and Beakes 1995; Gams and Arnold 2007; Haelewaters et al. 2021a, b), 2022)). The closely phylogenetic relationship of Pyxidiophora with Laboulbeniales was recently confirmed by molecular phylogenetic analyses (Blackwell et al. 2015; Tedersool et al. 2017; Haelewaters et al. 2019; Haelewaters et al. 2022).

Pyxidiophora includes about 30 species, mostly saprotrophic, growing on dung or decaying vegetable material, but a few (P. asterophora, P. lundqvistii, P. spinulorostrata) are mycoparasites (Kirschner 2003; Jacobs et al. 2005; Doveri and Coué 2016; Haelewaters et al. 2021a, b); 2022). As discussed by Haelewaters et al. (2021b), the life cycle of most species of Pyxidiophora is complicated, consisting of three different morphs: (1) a dispersal morph (Thaxteriola state) derived from an ascospore that delivers conidia to a fresh substrate, (2) a conidial morph developed on hyphae, and (3) an ascospore-producing perithecial morph to come full circle.

The conidiophores of Chalara s. lat. in Leotiomycetes are usually pigmented, being pale to dark brown, but those of a few species including C. schoenoplecti, C. sibika, C. siamense, C. hyalina and Chalara state of Cryptendoxyla hypophloia were reported to have hyaline to subhyaline conidiophores (Nag Raj and Kendrick 1975; McKenzie et al. 2002). In the phylogenetic tree (Wenping and Yongzhao 2023), the two species, C. hyalina and C. schoenoplecti, clustered together as a strongly supported clade distinct from other Chalara s. lat. species. The other phylogenetic analyses showed that Chalara hyalina and C. schoenoplecti belonged to Pyxidiophoraceae (Blackwell et al. 2015; Tedersool et al. 2017; Haelewaters et al. 2019, 2021a, b, 2022). The first formed conidia among these species with hyaline conidiophores and conidiogenous cells were described with different morphology from the normal cylindrical conidia, for example, the turbinate in C. sibika, and the subglobose or ellipsoid in C. hyalina, C. schoenoplecti and C. siamense (Subramanian and Sudha 1986; Morgan-Jones et al. 1984; Traue and Arnold 1991; McKenzie et al. 2002).