Heterothallia

Heterothallia is a reproductive mechanism in fungi . Sexual processes take place exclusively between genetically different mycelia or their sex cells. The terms self-incompatibility or self-sterility are also used for heterothallia . The opposite of the heterothallia is the homothallia .

The phenomenon of heterothallia was discovered and described in 1904 by Albert Francis Blakeslee in yoke mushrooms .

Heterothallic taxa are characterized by the fact that their thallus can only be assigned to one type of crossing or mating. A conjugation between two thalli is therefore only possible if they differ in terms of their type of crossing. Thalli of the same mating type cannot fuse with one another, they are self-sterile. The different mycelia are designated with (+) or (-) . The designation male or female is avoided because the mycelia do not differ morphologically.

A distinction is made between two types.

In morphological heterothallia , only one type of "sexual organ" is formed on a mycelium that has arisen from a spore . These "organs" can either release or take up nuclei during conjugation. This form is also known as a diocese .

In physiological heterothallia , both nuclear donating and receiving "sexual organs" are formed on a mycelium that has arisen from a spore. However, two differently polarized "organs" on the same mycelium are themselves incompatible and therefore cannot mutually release nuclei. The mycelium is monoecious .

In homothallia, the mycelium is also monoic and also self-fertile . The "sexual organs" of one and the same mycelium can therefore exchange nuclei for one another.

Except for yoke mushrooms , these mechanisms occur in other mushroom taxa, such as tube and stand mushrooms .

literature

• Blakeslee, AF (1904): Sexual reproduction in the Mucorineae. Proc. Amer. Acad. Arts Sci. (40): 205-319.
• Burgeff, H. (1928): Variability, inheritance and mutation in Phycomyces blakesleeanus. Z. induct. Descent. u. Inheritance (49): 26-94