Methods of sexual reproduction
The following are the five methods, which the fungi employ to bring the compatible nuclei together for fusion.
1. Planogametic copulation
2.Gametangial contact (Gametangy)
3. Gametangial copulation (Gametangiogamy)
4. Spermatization
5. Somatogamy
1. Planogametic copulation or conjugation
A planogamate is a motile gamete or sex cell. The fusion of two gametes, one or both of which are motile is called planogametic copulation.
This type of sexual reproduction is common in aquatic fungi.
There are three different types of planogametic copulation. Eg. Allomyces.
a. Isogamy:
In this type morphologically similar but compatible type of mating type of gametes unite to form a motile zygote. e.g. Synchytrium.
b. Anisogamy:
It involves union of one larger gamete with another smaller gamete. The resultant zygote is motile.
c. Heterogamy:
In this type, a non-motile female gamete (oosphere) is fertilized by a motile male gamete.
2. Gametangial contact
In this method the male gamete (antheridium) and the female gamete (oogonium) come in contact and one or more nuclei from the male gamete enter the female gamete, oogonium dissolved in the intervening wall through a pore or through a fertilization tube.
Like Pythium, Albugo (oomycetes).
3. Gametangial copulation:
This is a process of fusion of entire contents of the two mating gametangia.
There are two types. a. Mixing of entire protoplasm of male and female gametangia Two gametangia meet and their entire contents fuse in the female gametangium leading to formation of a zygote.
