When one of the parents of progeny is unknown, and the species can self-fertilize, we need to account for the possibility of selfing in the genetic relationship matrix. For example, in eucalyptus species, it is quite common to assume up to 0.3 probability of selfing (Grattapaglia et al., 2004; Patterson et al., 2004). If the selfing is not accounted for, the additive genetic variance will be biased upward because the progeny are not all half-sibs – they are more closely related, and therefore more similar, than the model assumes.