Differentiation of somatic embryos from protoplasts isolated from embryogenic suspension cultures of Abies alba L.

Embryogenic suspension cultures of Abies alba were established using an embryogenic suspensor mass culture originating from the zygotic embryo in immature seed explants (Schuller et al. 1989). Protoplasts were isolated from the suspension material. The protoplasts were immobilized in alginate layers in order to follow the development of single protoplasts. During the first days of protoplast culture a modified Kao and Michayluk (1975) medium proved to be necessary for subsequent divisions. The formation of proembryos succeeded within 2-3 weeks when subcultured with a modified Schenk and Hildebrandt (1972) liquid medium. Light, enhanced sugar concentration, and the addition of abscisic acid led to the formation of slightly green "torpedo"-shaped somatic embryos after 6-8 weeks from protoplast isolation.