Additive Variance and Open‐Pollinated Progenies Under Mixed Mating

Open‐pollinated progeny tests are still widely interpreted as if all the individuals within a maternal family were true half‐sibs. However, in species with mixed mating systems, this assumption is often biologically unrealistic and may bias the estimation of the additive variance, narrow‐sense heritability and expected selection gains. It concerns crops, forages, perennial species and any breeding population where selfing and outcrossing coexist. Here, it is argued that the routine half‐sib interpretation should no longer be treated as the default view of open‐pollinated families in mixed‐mating populations. Here, I build on the covariance framework of relatives under mixed selfing and random mating to interpret maternal progenies through the mean coancestry within families rather than through a fixed half‐sib coefficient. The increasing availability of molecular markers now makes it feasible to infer mating systems, realized relatedness and pedigree structures, more accurately, allowing breeders to replace convenience‐based assumptions with biologically informed genetic evaluations.