Two-celled teliospore of Gymnosporangium globosum

Teliospore (sometimes called teleutospore) is the thick-walled resting

spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

of some

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

( rusts and smuts), from which the

basidium A basidium () is a microscopic sporangium (a spore-producing structure) found on the hymenophore of fruiting bodies of basidiomycete fungi which are also called tertiary mycelium, developed from secondary mycelium. Tertiary mycelium is highly-c ...

arises.

Development

They develop in '' telia'' (sing. ''telium'' or ''teliosorus''). The telial host is the primary host in heteroecious rusts. The aecial host is the alternate host (look for pycnia and

aecia An aecium (plural aecia) is a specialised reproductive structure found in some plant pathogenic rust fungi that produce aeciospores. Aecia may also be referred to as "cluster cups". The term aecidium (plural aecidia) is used interchangeably but i ...

). These terms apply when two hosts are required by a heteroecious rust fungus to complete its life cycle.

Morphology

Teliospores consist of one, two or more dikaryote cells. Teliospores are often dark-coloured and thick-walled, especially in species where they overwinter (acting as chlamydospores). Two-celled teliospores formerly defined the genus ''

Puccinia ''Puccinia'' is a genus of fungi. All species in this genus are obligate plant pathogens and are known as rusts. The genus contains about 4000 species. The genus name of ''Puccinia'' is in honour of Tommaso Puccini (died 1735), who was an Italia ...

''. Here the wall is particularly thick at the tip of the terminal cell which extends into a beak in some species. Teliospores consist of dikaryote cells. As the teliospore cells germinate, the nuclei undergo

karyogamy Karyogamy is the final step in the process of fusing together two haploid eukaryotic cells, and refers specifically to the fusion of the two nuclei. Before karyogamy, each haploid cell has one complete copy of the organism's genome. In order for ...

and thereafter

meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately resu ...

, giving rise to a four-celled

with

haploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

basidiospore A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are pro ...

References

*C.J. Alexopolous, Charles W. Mims, M. Blackwell, ''Introductory Mycology, 4th ed.'' (John Wiley and Sons, Hoboken NJ, 2004) Germ cells Fungal morphology and anatomy Mycology {{Basidiomycota-stub

Development

Morphology

See also

References