连香树体细胞胚发生及植株再生体系建立

Establishment of Somatic Embryogenesis and Plant Regeneration of Cercidiphyllum japonicum

连香树(Cercidiphyllum japonicum)是连香树属的落叶乔木,为中国二级保护植物。本研究首次建立了一种稳定、高效的连香树体细胞胚发生及植株再生的方法。以未成熟种子中的幼胚为外植体,在附加1.0 mg/L2,4-D和0.5 mg/L 6-BA的MS培养基上培养5周,愈伤组织的诱导率为59.33%,在后续的增殖培养中100%转化为胚性愈伤组织。最适的胚性愈伤组织增殖培养基为附加0.1 mg/L的NAA、0.1 mg/L的6-BA、0.5 g/L活性炭和5%香蕉泥的MS培养基,增殖量达到1.5797 g。在增殖培养基中胚性愈伤组织实现了体细胞胚的分化发生,胚性愈伤组织最初都产生球形体细胞胚,在培养后期转化为心形期、鱼雷期和子叶期的体细胞胚。子叶期体细胞胚最终在无植物生长调节剂的MS培养基中萌发出苗,在附加1.0 mg/L IBA的MS培养基培养30 d后生根且植株健壮。

Cercidiphyllum japonicum is a second class protected wild plant of Cercidiphyllum.In this study,a stable and efficient method for somatic embryogenesis and regeneration was established for the first time.Immature embryos were used as explants and cultured on MS medium supplemented with 1.0 mg/L 2,4-D,0.5 mg/L 6-BA for 5 weeks,the callus induction rate was 59.33%,and 100%transformed into embryogenic callus in subsequent proliferation culture.The optimal medium for embryogenic callus proliferation was MS supplemented with 0.1 mg/L NAA,0.1 mg/L 6-BA,0.5 g/L activated carbon and 5%mashed banana,and the growth capacity reached 1.5797 g.Somatic embryos were differentiated from embryogenic callus in proliferative medium.All embryogenic callus initially produced spherical somatic embryos,which were transformed into heart-,torpedo-and cotyledon-shaped somatic embryos.The seedlings of somatic embryos were eventually differentiated in MS medium without plant growth regulators.After 30 days of culture in MS medium containing 1.0 mg/L IBA,the plants took root and were robust.