Interpretation and Use of Estimates of Heritability and Genetic Variances in Plant Breeding1

Estimates of genetic variance and heritability provide useful guidelines for answering many questions which arise in a plant breeding program. In this paper we have attempted to (a) delineate appropriate questions which can be answered by estimation of genetic variance components and heritabilities (b) examine the assumptions necessary for estimation and (c) clarify the limitations imposed on interpretation of the estimates by the assumptions.