Principles of Plant Breeding (2+1)

Types of heritability

• There aretwo estimates of heritability.

1 Broad sense heritability.
Heritability estimated usingthe total genetic variance (VG) is called broad senseheritability. It is expressed mathematically as: H = VG/VP

2 Narrow sense heritability.
Because the additivecomponent of genetic variance determines theresponse to selection, the narrow sense heritabilityestimate is more useful to plant breeders than thebroad sense estimate. It is estimated as: H2 = VA/VP
The magnitude of narrow sense heritabilitycannot exceed, and is usually less than, the correspondingbroad sense heritability estimate