(GCA) the relative ability of a individual to transmit genetic superiority to its offspring when crossed with other individuals —note 1. the general combining ability of a parent signifies the average performance of its progenies in various crosses, compared with progenies of other parents in the same test —note 2. the breeding value of a parent is twice its GCA —see additive genetic variation, breeding value, combining ability, progeny, specific combining ability This definition last updated 10/24/2008