SOCR 330 Lecture Notes - Heritability, Genetic Variation
Document Summary
Vp = va + vd + ve + v(g x e) Genetic variation (additive variance va and dominance variance vd) Environmental variation (environmental variance ve + genotype x environmental interaction variance v(g x e) ) Vp = va + vd + ve = v (g x e) Total observed phenotypic variation = genetic + environmental variation. Field or greenhouse trials of different crop varieties. Difficult to ensure all genotypes in identical environment. Heritability measures how much of phenotypic variation for a trait in a given population is due to genotypic variation. Heritability is important to animal and plant breeders because the heritability of a quantitative trait tells us how much the trait will respond to selection. Narrow sense heritability (h2) best predictor of response to selection. Realized heritability can be calculated from selection response. A bull weighing 1351 lbs and a cow weighing 1121 lbs were selected from a herd with a mean live weight of 1095. 7 lbs and mated.