Principles of Genetics and Breeding

11.1.6 Properties of heritability

1. It is the property of a character. Characters of fertility and reproduction usually have low heritability. Characters of growth and conformation have high heritability.

2. The range of h² is from 0 to 1. The same character may have different h² estimates depending on the method of estimation and the population concerned. The populations have actual gene frequency differences, which are reflected in the magnitude of the variance components used for h² calculation. Hence, heritability is also a property of the population.

3. The environment where the population is reared influences the magnitude of variance components. More variable conditions in environment decrease the h² estimate where as more uniformity increases it.
4. A population subjected to several generations of selection for any character exhibits a low heritability due to decreased genetic variance.
5. Inbreeding in a population also decreases the heritability estimate due to increased genetic uniformity and increase in environmental variance.