Editing Basidiomycota (section)

==Variations in lifecycles==
Many variations occur: some variations are self-compatible and spontaneously form dikaryons without a separate compatible thallus being involved. These fungi are said to be homothallic, versus the normal heterothallic species with mating types. Others are secondarily homothallic, in that two compatible nuclei following meiosis migrate into each basidiospore, which is then dispersed as a pre-existing dikaryon. Often such species form only two spores per basidium, but that too varies. Following meiosis, mitotic divisions can occur in the basidium. Multiple numbers of basidiospores can result, including odd numbers via degeneration of nuclei, or pairing up of nuclei, or lack of migration of nuclei. For example, the chanterelle genus ''[[Craterellus]]'' often has six-spored basidia, while some corticioid ''[[Sistotrema]]'' species can have two-, four-, six-, or eight-spored basidia, and the cultivated button mushroom, ''[[Agaricus bisporus]]''. can have one-, two-, three- or four-spored basidia under some circumstances. Occasionally, monokaryons of some taxa can form morphologically fully formed basidiomes and anatomically correct basidia and ballistic basidiospores in the absence of dikaryon formation, diploid nuclei, and meiosis. A rare few number of taxa have extended diploid lifecycles, but can be common species. Examples exist in the mushroom genera ''[[Armillaria]]'' and ''[[Xerula]]'', both in the [[Physalacriaceae]]. Occasionally, basidiospores are not formed and parts of the "basidia" act as the dispersal agents, e.g. the peculiar mycoparasitic jelly fungus, ''[[Tetragoniomyces]]'' or the entire "basidium" acts as a "spore", e.g. in some false puffballs (''[[Scleroderma (genus)|Scleroderma]]''). In the human pathogenic genus ''[[Cryptococcus (fungus)|Cryptococcus]]'', four nuclei following meiosis remain in the basidium, but continually divide mitotically, each nucleus migrating into synchronously forming nonballistic basidiospores that are then pushed upwards by another set forming below them, resulting in four parallel chains of dry "basidiospores".{{cn|date=January 2024}}

Other variations occur: some as standard lifecycles (that themselves have variations within variations) within specific orders.{{cn|date=January 2024}}

===Rusts===
[[rust (fungus)|Rusts]] ([[Pucciniales]], previously known as [[Uredinales]]) at their greatest complexity, produce five different types of spores on two different host plants in two unrelated host families. Such rusts are heteroecious (requiring two hosts) and macrocyclic (producing all five spores types). Wheat [[stem rust]] is an example. By convention, the stages and spore states are numbered by [[Roman numerals]]. Typically, basidiospores infect host one, also known as the alternate or sexual host, and the mycelium forms [[pycnidia]], which are miniature, flask-shaped, hollow, submicroscopic bodies embedded in the host tissue (such as a leaf). This stage, numbered "0", produces single-celled spores that ooze out in a sweet liquid and that act as nonmotile [[spermatia]], and also protruding [[receptive hyphae]]. [[Insect]]s and probably other [[Vector (epidemiology)|vectors]] such as rain carry the spermatia from spermagonium to spermagonium, cross inoculating the mating types. Neither thallus is male or female. Once crossed, the dikaryons are established and a second spore stage is formed, numbered "I" and called [[aecia]], which form dikaryotic [[aeciospore]]s in dry chains in inverted cup-shaped bodies embedded in host tissue. These aeciospores then infect the second host, known as the primary or asexual host (in macrocyclic rusts). On the primary host a repeating spore stage is formed, numbered "II", the [[urediospore]]s in dry pustules called [[uredinia]]. Urediospores are dikaryotic and can infect the same host that produced them. They repeatedly infect this host over the growing season. At the end of the season, a fourth spore type, the [[teliospore]], is formed. It is thicker-walled and serves to overwinter or to survive other harsh conditions. It does not continue the infection process, rather it remains dormant for a period and then germinates to form basidia (stage "IV"), sometimes called a [[promycelium]]. In the Pucciniales, the basidia are cylindrical and become 3-[[septum|septate]] after meiosis, with each of the 4 cells bearing one basidiospore each. The basidiospores disperse and start the infection process on host 1 again. [[Autoecious]] rusts complete their life-cycles on one host instead of two, and microcyclic rusts cut out one or more stages.{{cn|date=January 2024}}

===Smuts===
The characteristic part of the life-cycle of [[smut (fungus)|smuts]] is the thick-walled, often darkly pigmented, ornate, teliospore that serves to survive harsh conditions such as overwintering and also serves to help disperse the fungus as dry [[Diaspore (botany)|diaspores]]. The teliospores are initially dikaryotic but become diploid via karyogamy. Meiosis takes place at the time of germination. A promycelium is formed that consists of a short hypha (equated to a basidium). In some smuts such as ''[[Mycosarcoma maydis]]'' the nuclei migrate into the promycelium that becomes septate (i.e., divided into cellular compartments separated by cell walls called ''[[Septum#In mycology|septa]]''), and haploid yeast-like conidia/basidiospores sometimes called sporidia, bud off laterally from each cell. In various smuts, the yeast phase may proliferate, or they may fuse, or they may infect plant tissue and become hyphal. In other smuts, such as ''[[Tilletia tritici|Tilletia caries]]'', the elongated haploid basidiospores form apically, often in compatible pairs that fuse centrally resulting in H-shaped [[diaspore]]s which are by then dikaryotic. Dikaryotic conidia may then form. Eventually the host is infected by infectious hyphae. Teliospores form in host tissue. Many variations on these general themes occur.{{cn|date=January 2024}}

Smuts with both a yeast phase and an infectious hyphal state are examples of [[Polymorphism (biology)|dimorphic]] Basidiomycota.<ref name="Prillinger_2002">{{cite journal |last1=Prillinger |first1=Hansjörg |last2=Lopandic |first2=Ksenija |last3=Schweigkofler |first3=Wolfgang |last4=Deak |first4=Robert |display-authors=3 |date=February 2002 |title=Phylogeny and Systematics of the Fungi with Special Reference to the Ascomycota and Basidiomycota |url=https://www.researchgate.net/publication/11274315 |journal=Chemical Immunology |volume=81 |issue=9413 |pages=207–295 |doi=10.1159/000058868 |pmid=12102002 |access-date=2024-03-12}}</ref> In plant parasitic taxa, the saprotrophic phase is normally the yeast while the infectious stage is hyphal. However, there are examples of animal and human parasites where the species are dimorphic but it is the yeast-like state that is infectious.<ref name="Carres_2010">{{cite journal |last1=Rodriguez-Carres |first1=Marianela |last2=Findley |first2=Keisha |last3=Sun |first3=Sheng |last4=Dietrich |first4=Fred S. |last5=Heitman |first5=Joseph |date=2010-03-10 |title=Morphological and Genomic Characterization of Filobasidiella depauperata: A Homothallic Sibling Species of the Pathogenic Cryptococcus Species Complex |journal=PLOS ONE |volume=5 |issue=3  |pages=e9620 |doi=10.1371/journal.pone.0009620 |doi-access=free |pmid=20224779 |pmc=2835752 |bibcode=2010PLoSO...5.9620R }}</ref> The genus ''[[Filobasidiella]]'' forms basidia on hyphae but the main infectious stage is more commonly known by the [[anamorph]]ic yeast name ''[[Cryptococcus (fungus)|Cryptococcus]]'', e.g. ''[[Cryptococcus neoformans]]''<ref name="Erke_1976">{{cite journal |last1=Erke |first1=K. H. |date=October 1976 |title=Light microscopy of basidia, basidiospores, and nuclei in spores and hyphae of Filobasidiella neoformans (Cryptococcus neoformans) |journal=Journal of Bacteriology |volume=128 |issue=1 |pages=445–455 |doi=10.1128/jb.128.1.445-455.1976 |pmid=789347 |pmc=232872 }}</ref> and ''[[Cryptococcus gattii]]''.<ref name="Carres_2010" />

The dimorphic Basidiomycota with yeast stages and the pleiomorphic rusts are examples of fungi with [[anamorph]]s, which are the asexual stages. Some Basidiomycota are only known as anamorphs. Many are called basidiomycetous yeasts, which differentiates them from ascomycetous yeasts in the [[Ascomycota]]. Aside from yeast anamorphs and uredinia, aecia, and pycnidia, some Basidiomycota form other distinctive anamorphs as parts of their life cycles. Examples are ''[[Collybia tuberosa]]''<ref>{{cite web|url=http://www.bio.utk.edu/mycology/ATBI/Photos/12000to12099/12074.jpg |title=Archived copy |access-date=2007-09-13 |url-status=dead |archive-url=https://web.archive.org/web/20071025221100/http://www.bio.utk.edu/mycology/ATBI/Photos/12000to12099/12074.jpg |archive-date=2007-10-25 }}</ref> with its apple-seed-shaped and coloured [[sclerotium]], ''[[Dendrocollybia racemosa]]''<ref>{{Cite web|url=http://www.pnwfungi.org/pdf%20files/manuscripts%20volume%201/pnwf20069.pdf|archiveurl=https://web.archive.org/web/20070927203256/http://www.pnwfungi.org/pdf%20files/manuscripts%20volume%201/pnwf20069.pdf|url-status=dead|title=Microsoft Word – Machnicki revised for pdf final august 24<!-- Bot generated title -->|archive-date=27 September 2007|access-date=3 March 2022}}</ref> with its sclerotium and its ''[[Tilachlidiopsis racemosa]]'' conidia, ''[[Armillaria]]'' with their [[mycelial cord|rhizomorphs]],<ref name="autogenerated1">{{Cite web |url=http://www.bioart.co.uk/lux/mycit.html |title=LUXGENE.COM: The glow-in-the-dark website |access-date=2007-09-13 |archive-date=2007-09-28 |archive-url=https://web.archive.org/web/20070928040055/http://www.bioart.co.uk/lux/mycit.html |url-status=dead }}</ref> ''[[Hohenbuehelia]]''<ref>{{cite web |url=http://www.uoguelph.ca/~gbarron/ZBiodiversity/hohenbue.htm |title=Hohenbue<!-- Bot generated title --> |access-date=2007-04-17 |archive-url=https://web.archive.org/web/20061221075703/http://www.uoguelph.ca/~gbarron/ZBiodiversity/hohenbue.htm |archive-date=2006-12-21 |url-status=dead }}</ref> with their ''[[Nematoctonus]]'' [[nematode]] infectious, state<ref>{{cite web |url=http://www.uoguelph.ca/~gbarron/ZBiodiversity/8knobs.htm |title=8knobs<!-- Bot generated title --> |access-date=2007-04-17 |archive-url=https://web.archive.org/web/20061221075333/http://www.uoguelph.ca/~gbarron/ZBiodiversity/8knobs.htm |archive-date=2006-12-21 |url-status=dead }}</ref> and the coffee leaf parasite, ''[[Mycena citricolor]]'',<ref name="autogenerated1" /> and its ''[[Decapitatus flavidus]]'' [[propagule]]s called gemmae.