Principles of Plant Breeding (2+1)

Mechanisms favoring self pollination:

Bisexuality:
The male and female reproductive units are present in the same flower.E.g., Hibiscus, Wheat, Paddy, etc.
Homogamy:
Here anther and stigma of bisexual flower mature at the same time.E.g. Green peas, etc.
Cleistogamy:
Flowers do not open at all in case of bisexual flowers ensures self pollination.E.g., Lettuce, Legumes, etc.
Flower structure:
In cotton the young pistil must grow through a staminal sheath, the pollen is shed on the respective stigma as it is pushed through the staminal column there by self pollination is favored.