ESTIMATING HERITABILITY OF FAMILIES DERIVED FROM SINGLE PLANTS AT AN ADVANCED GENERATION OF SELF-FERTILIZING SPECIES: DEVELOPING GENERAL FORMULAS AND ESTIMATING SPRING WHEAT TRAITS

Abstract

Genetic expectations of total genetic variance, and between-family and within-family variance components were developed for any given generation (Fn) derived from single selfed plants of an earlier generation (Fk). A formula to estimate the heritability (h2) in any desired generation (Fn) was developed on the basis of these expectations. This formula estimates the value of the genetic variance from the phenotypic variance adjusted to the F2 generation. Heritability estimates of culm length, heading date, and mean grain weight from two populations of F6 families, each derived from a single F5 plant, were computed using this formula, and a formula which estimates the value of the genetic variance from the phenotypic variance in the Fn generation (“Fn estimates”). The FN h2 estimates at F6 were always higher than those adjusted to F2 variance, due to the increase in additive variance and the reduction in dominance variance.