Abscisic acid and osmotic induction of synchronous somatic embryo development of sweet potato

Somatic embryos of sweet potato have potential as synthetic seeds. The effe cts of abscisic acid (ABA) (0.0, 0.1, 1.0, 10.0 and 50.0 muM) were examined to improve synchrony and proliferation of somatic embryos. Transferring em bryonic cultures at day 7 to solid medium with 0.1 or 1.0 muM ABA produced more torpedo and cotyledonary somatic embryos compared to those cultures tr ansferred at day 0. The development of embryos in suspension culture supple mented with ABA was poor. However, when calli proliferation cultures were i n gelled medium and pulsed with 0.1 muM ABA for 14 d, the number of somatic embryos increased. Proembryonic masses cultured in mannitol-containing med ium (Y = - 1.5 MPa) increased embryo development and synchrony of embryo de velopment. Thus, in this work ABA and mannitol have been shown to improve b oth the total number and the synchrony of sweet potato somatic embryos.