Induction of embryogenesis in cultured mature zygotic embryos of Abies fraseri (Pursh) Poir

Embryo suspensor masses were induced by culture of isolated mature zygotic embryos of Fraser fir (Abies fraseri [Pursh] Poir.). Maximum induction frequencies were observed after 10 weeks culture on one-half strength Murashige and Skoog medium containing 10 μM thidiazuron and on one-half strength Verhagen and Wann medium containing 10 μM cytokinin [6-(dimethylallylamino)purine, 6-benzyladenine, or thidiazuron). Proliferation of embryo suspensor masses occurred on one-half strength Verhagen and Wann medium supplemented with 10 μM cytokinin. When embryo suspensor masses were transferred to media containing 5-80μM abscisic acid, cotyledonary-stage embryos were formed. Somatic embryos germinated on medium lacking plant growth regulators, but abnormal cotyledonary-stage somatic embryos with stunted cotyledons and reduced embryo axes were also observed.