Quantitative Inheritance in Plant Breeding. Transgressive segregation. Plants with traits that arise by segregation of genes for a quantitative character that fall outside the range of the parents are known as transgressive segregates
Quantitative Inheritance in Plant Breeding
It follows then that
VP = VG+VE + VGE
VP = VG + VE + VGE
So now: VP = VA + VD + VI + VE + VGE
Types of Heritability Estimates.
Heritability may be given by H = VG /VP = VG/(VG+VE+VGE).
H = (VG /VP) x 100
The result is represented as heritability in the narrow sense (h2), Narrow-sense heritability cannot exceed, and is usually less than, broad-sense heritability.
Heritability and Selection
If a plant breeder is working with clonally propagated crops such as sugarcane, bananas, or if the crop reproduces apomictically,
estimates of broad-sense heritability would be appropriate
because vegetative propagation and apomixis fix both additive and non-additive (dominance plus epistatic) gene action and transfer it from parent to offspring.
Selection Intensity and Genetic Advance
Gs = (i)(√VP)(h2)
Gs = (c)(i)(√VP)(h2).
Therefore, the narrow-sense heritability percentage estimate was
h2 = [0.114/(0.114 + 0.035 + 0.022)]