Pachnocybe
{{Short description|Genus of fungi}}
{{Taxobox
| image =
| image_caption =
| regnum = Fungi
| divisio = Basidiomycota
| classis = Pucciniomycetes
| ordo = Pachnocybales
| familia = Pachnocybaceae
| familia_authority = Oberw. & R.Bauer
| genus = Pachnocybe
| type_species =
| type_species_authority =
}}
The Pachnocybe are a genus of fungi, within the monotypic family of Pachnocybaceae {{Au|Oberw. & R.Bauer, 1989}}, and within the monotypic order of Pachnocybales, within the class Pucciniomycetes. They are parasitic on plants or saprobic on rotten wood.
History
The genus of Pachnocybe was created in 1836, when English cryptogamist Miles Joseph Berkeley moved several species from other genera into his new genus. Such as Sporocybe albida became Pachnocybe albida.
The genus name of Pachnocybe was derived from Greek word Pachne meaning hoar-frost and also cybe meaning head.
Hughes in 1958 in his review of classical hyphomycete genera selected Pachnocybe ferruginea as type species of the genus. He also excluded Pachnocybe grisea as a synonym of Cephalotrichum purpureofuscum (in the family Microascaceae).{{cite journal |last1=Hughes |first1=S.J. |title=Revisiones hyphomycetum aliquot cum appendice de nominis rejiciendis. |journal=Can. J. Bot. |date=1958 |volume=36 |issue=6 |pages=727–836|doi=10.1139/b58-067 }}
The genus Pachnocybe was then assigned as fungi imperfecti by Ellis in 1971,{{cite book |last1=Ellis |first1=M.B. |title=Dematiaceous Hyphomycetes. |date=1971 |publisher=Commonwealth Mycological Institute |location=Kew, Surrey, England |page=608}} then in 1980
Carmichael et al. suggested it had an ascomycetous relationship.{{cite book |last1=Carmichael |first1=J.W. |last2=Kendrick |first2=W.B. |last3=Conners |first3=I.L. |last4=Sigler |first4=L. |title=Genera of Hyphomycetes. |date=1980 |publisher=University of Alberta Press. |location=Alberta, Canada}} Then Oberwinkler and Bandoni in 1982, after studying the morphology of species Pachnocybe ferruginea found strong basidiomycetous relationships.{{cite journal |last1=Oberwinkler |first1=F. |last2=Bandoni |first2=R.J. |title=A taxonomic survey of the gastroid, auricularioid Heterobasidiomycetes. |journal=Can. J. Bot. |date=1982 |volume=60 |issue=9 |pages=1726–1750|doi=10.1139/b82-221 }} In 1986, Kropp and Corden proposed it should be placed in the ''Chionosphaeraceae family.
The genus was later placed in order Atractiellales,{{cite journal |last1=Walker |first1=William F. |title=5S rRNA sequences from Atractiellales, and Basidiomycetous yeasts and fungi imperfecti |journal=Systematic and Applied Microbiology |date=October 1984 |volume=5 |issue=3 |pages=352–359 |doi=10.1016/S0723-2020(84)80037-5}} due to species in the group having gastroid basidia and simple septal pores.
The genus Pachnocybe was placed in family Septobasidiaceae (Septobasidiales order), even though many Septobasidiaceae species were mostly parasitic on scale insects.{{cite journal |last1=Henk |first1=Daniel A. |last2=Vilgalys |first2=Rytas |title=Molecular phylogeny suggests a single origin of insect symbiosis in the Pucciniomycetes with support for some relationships within the genus Septobasidium |journal=American Journal of Botany |date=September 2007 |volume=94 |issue=9 |pages=1515–1526 |doi=10.3732/ajb.94.9.1515|pmid=21636518 |doi-access=free }} The family placement was based on weakly supported phylogenetic inference,Frieders, E. M. 1997. An integrated approach to understanding the moss parasites and their role in basidiomycete evolution. Ph.D. dissertation, University of Minnesota, St. Paul, Minnesota, USA. and the reported presence of 'microscala', (which are membrane complexes, consisting of layers of membranes of endoplasmic reticulum, interconnected by a regular array of rodlets which may also connect to the mitochondriaDavid J. McLaughlin and Joseph W. Spatafora (Editors) {{google books|Cyv7CAAAQBAJ|Systematics and Evolution (2013)|page=46}}) (Kleven and McLaughlin, 1989; Bauer and Oberwinkler, 1990).
Description
They were originally described in 1836 and 1863 as having "a solid stem, filiform below, clavate above, dusted with minute spores".Mordecai Cubitt Cooke {{google books|t_ZAAQAAMAAJ|Handbook of British Fungi, with full descriptions of all the species and illustrations of the genera, Volume 2 (1863)|page=550}}
Species in the Pachnocybaceae family have a basidiomata (spore stem) that stilboid (pin-shaped), stipitate (possessing a stipe, stem) and capitate (resembles the head of a pin), smooth, not viscid or gelatinous in form. The fertile head is globose (rounded), hyaline (glass-like) or pale yellowish, with the entire surface composed of packed basidia (spore-producing structures). The dark reddish brown stipe is composed of closely adherent thick walled hyphae (long, branching, filamentous structure). The hyphae have simple septal spores, with no clamp connections and fertile hyphae are frequently branched. The basidia is clavate to cylindrical (in form), aseptate (undivided), with basal clamp connections and an apical cluster of 4-6 minute sterigmata (small supporting structures). The basidiospores are ellipsoidal (in form), hyaline or yellowish with smooth and thick walls.P. F. Cannon and P. M. Kirk (Editors) {{google books|Lw1VLSH1xnAC|Fungal Families of the World (2006)|page=253}}
Pachnocybe ferruginea was thought to be a dikaryotic mycelium that formed brown capitate basidiocarps. However, one form had associated blastic-sympodial conidia, larger basidiocarps, chlamydospores, and had a slower growth rate. Single uninucleate basidiospores of both forms produced dikaryotic mycelium with simple septal pores and holobasidia in which karogamy and meiosis occurred. Thus, P. ferruginea has a primary homothallic life cycle. Spores from conidial isolates gave rise to both basidiocarps and the conidial form demonstrating that the conidial form is the anamorph of P. ferruginea.
They have a primary homothallic life cycle.
List of species
The genus Pachnocybe contain 4 known species;{{cite web |title=Pachnocybe - Search Page |url=http://www.speciesfungorum.org/Names/Names.asp?strGenus=Pachnocybe |website=www.speciesfungorum.org |publisher=Species Fungorum |access-date=4 October 2022}}
- Pachnocybe acicula {{Au|Berk. (1836)}}
- Pachnocybe albida {{Au|(Fr.) Berk. (1836)}}
- Pachnocybe ferruginea {{Au|Berk. (1836)}}
- Pachnocybe incerta {{Au|(P. Karst.) S. Hughes (1958)}}
- Pachnocybe clavulata {{Au|Grove (1885)}} = Phaeoisaria clavulata Diatrypaceae
- Pachnocybe grisea {{Au|Berk. (1836)}} = Cephalotrichum purpureofuscum Microascaceae
2 other species are noted elsewhere but not listed in Species Fungorum.
- Pachnocybe rosea {{Au|Berk. & M.A. Curtis}} (found on the wood of Acacia julibrissin in America) M.C. Cooke (Editor) {{google books|H_BmAAAAcAAJ|Grevillea: a monthly record of cryptogamic botany and its literature, Volume 3 (1874)|page=62}}Buffalo Society of Natural Sciences {{google books|1MwoAAAAYAAJ|Bulletin of the Buffalo Society of Natural Sciences, Volume 3, Issues 4-5 (1877)|page=195}}
- Pachnocybe subulata {{Au|(Nees & T. Nees) Berk.}} (found on the bark of Robinia pseudoacacia species, William Gilson Farlow, Arthur Bliss Seymour and A. B. Seymour {{google books|YtYUAAAAYAAJ|A Provisional Host-index of the Fungi of the United States, Part 1 (1888)|page=28}} and in Scotland, on decaying plants and fir cones,George Dickie {{google books|UW3oYayICxUC|The Botanist's Guide to the Counties of Aberdeen, Banff, and Kincardine (1860)|page=334}})
Hosts
Pachnocybe ferruginea has been found on domestic wood, such as pine floorboards in a house,{{cite journal |last1=Mason |first1=E.W. |last2=Ellis |first2=M.B. |title=British species of Periconia. |journal=Mycological Papers |date=1953 |volume=56 |pages=1–127}} on a wine cask and also on timbers inside a mine (Levy and Lloyd, 1960,{{cite journal |last1=Levy |first1=J.F. |last2=Lloyd |first2=F.J. |title=A study of the fungi present in timbers in Tywarnhale Mine (Cornwall). |journal=Journal of the Institute of Wood Science |date=1960}}) within the UK.{{cite book |last1=Legon |first1=N.W. |last2=Henrici |first2=A. |last3=Roberts |first3=P.J. |last4=Spooner |first4=B.M. |last5=Watling |first5=R. |title=Checklist of the British and Irish Basidiomycota |isbn=1-84246-121-4 |date=2005 |publisher=Royal Botanic Gardens, Kew |location=London, U.K.}} It was also found in Douglas fir (Pseudotsuga menziesii) made utility poles in western Oregon, USA.Chun-Juan Wang and Robert A. Zabel {{google books|JoLwAAAAMAAJ| Identification Manual for Fungi from Utility Poles in the Eastern United States (1990)|page=161}}
Distribution
The order has a scattered distribution, they are recorded mostly in Europe, North America (including Canada,), some in Africa and rarely in India and the Pacific Ocean. They can be found in terrestrial and aquatic environments.{{cite journal |last1=Kleven |first1=N.L. |last2=McLaughlin |first2=D.J. |title=Sporulation of the Basidiomycete Pachnocybe ferruginea in Terrestrial and Aquatic Environments |journal=Mycologia |date=1988 |volume=80 |issue=6 |pages=804–810|doi=10.1080/00275514.1988.12025727 }}
Species Pachnocybe albida has been found on rotten logs of Buxus, Fraxinus and Quercus.{{cite book |last1=Ellis |first1=M.B. |last2=Ellis |first2=J.P. |title=Microfungi on Land Plants. |date=1985 |publisher=Croom Helm. |location=London |edition=2nd Edn. (1997)}}
References
Other sources
- C.J. Alexopolous, Charles W. Mims, M. Blackwell et al., Introductory Mycology, 4th ed. (John Wiley and Sons, Hoboken NJ, 2004) {{ISBN|0-471-52229-5}}
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