Principles of Plant Breeding (2+1)

Factors affecting Heterosis

1. Mode of pollination: The magnitude of heterosis is generally higher in cross pollinated species than in self pollinated species.
2. Genetic diversity of parents: The expression of heterosis is influenced by genetic diversity of parents. For example in alfalfa and cotton, greater heterosis was associated with greater parental diversity.
3. Genetic base of parents: Higher heterosis is associated with broad genetic base of the parents.
4. Adaptability of parents: Heterosis is associated with wider adaptability of the parents, because there is close association between adaptability and genetic base.