
Cases of polyembryony have been reported in non-apomictic genotypes as a consequence of 2x Γ 4x hybridizations and in vitro culture of isolated nucelli. Aleza et al. demonstrate that embryogenic cells or proembryos, which normally remain quiescent, are formed by cleavage of the zygotic embryo. The development of these adventitious cells or embryos can take place in vivo and in vitro as a consequence of mechanic or genetic procedures that prevent the dominance of the initial zygotic embryo.