III- SEXUAL REPRODUCTION
Sexual reproduction in fungi involves union of two compatible nuclei or somatic cells or somatic hyphae for the formation of new individuals.
Phases of sexual reproduction- three typical phases occur in sequence during the sexual reproduction.
1. Plasmogamy:
In plasmogamy anastomosis of two cells or gametes and fusion of their protoplasts take place.
In the process the two haploid nuclei of opposite sexes (compatible nuclei) are brought together.
2. Karyogamy:
The fusion of two haploid nuclei brought together as a result of plasmogamy is called karyogamy (Gr. karyon = nut, nucleus + gamos = marriage).
This stage follows immediately after plasmogamy.
Nuclear fusion, which eventually takes place in all sexually reproducing fungi, is followed by meiosis.
Karyogamy results in the formation of a diploid (2n) nucleus.
3. Meiosis:
Meiosis (Gr. meiosis=reduction) reduces the number of chromosomes to haploid and constitutes the third phase of the sexual reproduction.
