Isolation and in vitro culture of zygotes and central cells of Oryza sativa L.

All component cells of the embryo-sac before and after fertilization in rice were isolated by manual microdissection under conditions either free of enzymes or combined with a short pulse of enzymatic treatment. In general, the frequency of isolated unfertilized or fertilized egg cells or central cells reached 15-40%. Various component cells of the embryo-sac after isolation were distinguished by their own morphological characteristics. The isolated cells were cultured in a microchamber and fed with dividing rice suspension cells. Both unfertilized and fertilized egg cells and central cells were induced to divide. Among them only the fertilized egg cells (the zygotes) developed into proembryo-like multicellular structures. The frequency of the first zygotic division and the frequency of multicellular structures were higher using the non-enzymatic method than using the enzymatic one.