Maturation and plant recovery from embryogenic cells of Japanese larch: Effect of abscisic acid in relation to their morphology

Two embryogenic cell lines characterized by different morphology and color, white and red, were obtained from an immature zygotic embryo of Japanese larch (Larix leptolepis Gord.). Mature somatic embryos with cotyledons and regenerated plants were obtained from both cell lines. However optimal concentration of abscisic acid (ABA) for maturation varied depending on morphology of ECs. From the white ECs which intermingled with somatic embryos of very early stage, mature somatic embryos were induced on maturation medium containing 50 μM of ABA. On the other hand, mature somatic embryos with cotyledons were observed from the red ECs which consisted of somatic embryos of more developed stage on hormone-free medium or 0.1 μM ABA containing-medium.