Reproductive Terminology of Fungi


anamorph
An asexual or mitotic reproductive stage in a pleomorphic life cycle that also includes a teleomorph or meiotic reproductive stage.
aneuploid
A nucleus with a chromosome number that is not an exact multiple of the normal haploid number (2N+1, 2N-1, etc.)
anisogamy
Fusion of motile gametes that are unequal in size; occurs in some Chytridiomycetes, not in any plant pathogenic fungi.
biallelic
With two alleles for incompatibility; the inbreeding level and outbreeding level in biallelic fungi are both 50 percent.
bipolar
With incompatibility between homokaryons controlled by one pair of alleles; a single dikaryon gives rise to two different mating types; also referred as unifactorial.
compatibility type
A diploid stage that produces compounds that stimulate the development of gametangia in the other compatibility type; occurs in oomycetes.
compatible
Having the ability to fuse together and give rise to heterokaryons.
conidiation
Fusion between non-motile cells that can function as gametes or conidia and specialized female structures; occurs in ascomycetes.
dioecious
Having two types of diploid individuals, some with male gametangia only and some with female gametangia only; occurs in oomycetes, not in any plant pathogenic fungi.
dikaryon
A fungal stage in which all cells contain two nuclei; dikaryons may be homokaryotic or heterokaryotic.
diploid
A fungal stage in which the nuclei contain two genomes (2N). Diploid nuclei maybe homozygous or heterozygous.
gametangial contact
Fusion between an antheridium and an oogonium followed by fertilization of oospheres by antheridial nuclei; occurs in oomycetes.
gametangial fusion
Fusion between morphologically similar gametangia to form a zygote that develops into a zygospore or an ascus; occurs in zygomycetes and lower ascomycetes.
haploid
A fungal stage in which the nuclei contain one genome (N).
heterogenic incompatibility
Limiting of infertility to pairings of homokaryons that bring together like factors; these systems operate independently of homogenic incompatibility systems.
heterokaryon
A fungal stage that contains nuclei of different genotypes.
heteroplasmon
A fungal stage with cytoplasm from different individuals following plasmogamy.
heterothallic
Self-sterile; a dikaryon or diploid results from fusion of compatible mating types.
holomorph
The whole fungus consisting of all mitotic and meiotic stages in the life cycle.
holomorph diversity
A paradigm based on the concept that recognizes meiotic, pleomorphic, and mitotic fungal species.
homogenic incompatibility
Limiting of interfertility to pairings of homokaryons that bring together different alleles at the incompatibility loci (different mating types).
homokaryon
A fungal stage in which all nuclei are of the same genotype.
homothallic
Self-fertile; a dikaryon or diploid develops from single meiospores.
inbreeding
The level of compatibility between homokaryons derived from one dikaryotic or diploid parental genotype following meiosis.
incompatible
Lacking the ability to undergo fusion and form heterokaryons.
isogamy
Fusion of morphologically identical motile gametes; occurs in myxomycetes and chytridiomycetes.
karyogamy
Fusion of haploid nuclei to form a diploid stage.
mating type
A homokaryotic haploid stage that will produce a diploid or dikaryotic stage only after pairing with a compatible mating type.
meiospore
A spore that results directly from karyogamy and meiosis and consequently is characterized by genetic recombination.
meiotic holomorph
A fungus for which the only known reproductive stage is a meiotic or sexual stage.
mitospore
A spore that results directly from mitosis and consequently is not characterized by genetic recombination.
mitotic holomorph
A fungus for which the only known reproductive stage is a mitotic or asexual stage or two or more mitotic stages.
monoecious or hermaphroditic
With both male and female sex structures on the same individual.
monokaryon
A fungal stage in which all cells contain a single nucleus.
multiallelic
With a series of alleles at the locus or loci for incompatibility in a heterothallic species; multiallelic systems restrcit inbreeding and enhance outbreeding and are known in myxomycetes and basidiomycetes only.
oogamy
Fusion of motile sperm and non-motile egg; occurs in some chytridiomycetes, not in any fungal plant pathogens.
outbreeding
The level of incompatibility between homokaryons derived from different dikaryotic or diploid parental genotypes following meiosis.
parasexual cycle
A nuclear cycle that results in recombinant haploid genotypes without meiosis; it involves heterokaryosis, karyogamy to produce heterozygous diploid nuclei, and mitotic crossing over and/or nondisjunction and aneuploidy.
plasmogamy
Fusion of cells to bring nuclei and cytoplasm from two different individuals together in the same cell.
pleomorphic holomorph
A fungus with a meiotic or sexual reproductive stage and one or more mitotic or asexual reproductive stages.
primary homothallism
A condition in which a mating system is operating but two nuclei of compatible mating types are incorporated in each meiospore; the spores are therefore self fertile.
sclerotium
A hard vegetative resting structure consisting of thick-walled, usually pigmented, modified fungal cells.
somatogamy
Fusion of morphologically undifferentiated somatic cells; the method of sexual reproduction in basidiomycetes except rusts and smuts.
spermatization
Fusion of non-motile spermatia with specialized female reproductive structures; occurs in rusts ans some ascomycetes.
synanamorph
Term of individual anamorphs of pleomorphic species with two or more anamorphs.
teleomorph
A sexual or meiotic reproductive stage ina pleomorphic life cycle that also includes one or more asexual or mitotic reproductive stages.
tetrapolar
With incompatibility controlled by two pairs on non-linked alleles that segregate independently at meiosis; a single dikaryon gives rise to four different mating types; all tetrapolar systems are multiallelic and known in basidiomycetes only; also referred as bifactorial.
universal holomorph
A paradigm based on the concept that a morphologically expressed sexual or meiotic state will eventually be found for all fungal species.
vegetative incompatibility
Limiting of interfertility to pairings of homokaryotic, diploid, or dikaryotic vegetative stages that bring together like factors; a type of heterogenic incompatibility.