Telie
The Telie or Telium is a form of spore storage that occurs in the main fruit form of the rust fungi (Pucciniales). It produces the binuclear teliospores , in which karyogamy and meiosis occur and which later develop basidia . The teliospores usually also serve to overwinter the parasitic fungi and in spring form the basis for infestation of germinating plants. Telia are usually only up to a millimeter in size and stand out as small dark points on the host's epidermis . As the end point of sexual reproduction, the telia in the phenology of the rust fungi follow spermogonia , aecia and uredia . They grow partly on the same, partly on different hosts than aecia and spermogonia. The shape of the Telien and teliospores is in the taxonomy used to the main crop of the rust fungi in different form classes divide, such as Uromyces for mainly unicellular or Puccinia for primarily two-cell types.
Origin and structure
At the beginning of the telienation there are dikaryotic spores, which germinate on a suitable host and form a mycelium from binuclear hyphae . These spores can either be aeciospores originating directly from aecia or uredospores which are produced via the detour of the anamorphic uredia. In some species, the teliospores also grow directly from the uredia mycelium, so the uredia are transformed into telia. In many species, the telia produce long stalks, so-called pedicles, with one or more cells at the tip that represent the teliospores. Each cell has two nuclei and usually has thick walls that protect the inside of the cell from environmental influences. The teliospores exposed to the wind break off at the stem or at their base and fall to the ground or directly onto a new host plant. They often hibernate to re-infect plants the following spring. In the meantime, the nuclei first fuse and then meiosis . Only at this point in the development cycle does the fungus reproduce sexually, during which the cell nuclei from the spermogonia and aecia fuse together and produce new, recombined nuclei. The teliospores germinate by protruding basidia over a germ pore . The basidia grow partly as cell chains in which each link contains a nucleus, partly as simple cells from the germ pores. The nuclei are pinched off as basidiospores and, on suitable substrates, first develop spermogonia and then aecia. At this point the transition from the dikaryotic to the haplontic form of the rust fungi takes place.
Importance for the taxonomy
The common classification scheme of the rust fungi is based on the shape of the teliospores in order to assign the species to different genera . In the case of preserved species, single-cell teliospores are regarded as a characteristic feature of the genus Uromyces , while two-cell teliospores are usually assigned to the genus Puccinia . The genus Stereostratum exists for species with three germ pores per cell . Species with sessile spores are divided into the genera Phakopsora (subepidermically growing spore beds with an irregular spore arrangement), Physopella (chain-shaped teliospores in covered spore beds) and Dasturella (chain-shaped spores in open, fan-shaped beds) based on their telescopic shape .
swell
- Heinrich Dörfelt , Gottfried Jetschke (Ed.): Dictionary of mycology. 2nd Edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2001, ISBN 3-8274-0920-9 .