脱落酸和玉米素结合使用对杂交鹅掌楸体胚分化及发育的影响

Effects of Combined ABA and ZT Treatment on Somatic Embryogenesis and Development of Liriodendron sino-americanum

【目的】探讨了不同浓度脱落酸(ABA)和玉米素(ZT)处理对杂交鹅掌楸体胚发生发育的效应,为杂交鹅掌楸大规模繁殖技术的建立提供理论依据。【方法】以15-5202基因型的杂交鹅掌楸胚性愈伤组织为材料,比较在体胚分化阶段单独添加ABA以及同时添加ABA和ZT对体胚分化的影响;通过体胚发生数量统计、体胚生长状况观察等筛选出诱导效率高、体胚发育正常的体胚分化培养基。【结果】1)在体胚分化培养基中添加ABA对体胚的分化及成熟具有促进作用,添加0.5～1.5 mg·L^(-1) ABA可加快体胚发育,且体胚形态正常;添加2.0～2.5 mg·L^(-1) ABA时,虽使体胚分化率明显提高,但畸形胚比例增加;低浓度ABA处理30天后转入光培养2周体胚即可成熟;而未添加ABA处理的体胚在同样条件下未完全发育成熟,体胚呈白色、子叶淡黄色。2)在体胚分化培养基中同时添加ABA及ZT能提高体胚分化率及促进体胚发育; 2.0 mg·L^(-1) ABA结合0.2～0.4 mg·L^(-1) ZT处理后光培养2周,体胚形态发育正常,子叶分化明显,胚根健壮,生长状况较佳;未经过ZT处理的体胚生长发育较慢; ZT浓度高于0.6 mg·L^(-1)时体胚生长发育受到抑制,不利于体胚分化及成熟。【结论】在杂交鹅掌楸体胚分化培养基中添加2.0 mg·L^(-1) ABA和0.2～0.4 mg·L^(-1) ZT能够进一步提高体胚发生效率,促进体胚正常发育。

【Objective】 In this article, we aimed to establish large scale propagation methodologies for Liriodendron sino-americanum (hybrid Liriodendron ) and to this end we investigated how various combined treatments with the plant hormones abscisic acid(ABA)and zeatin(ZT)affect its somatic embryogenesis and development.【Method】 We successfully induced somatic embryos using the embryogenic callus of L. sino-americanum genotype 15-5202. We tested how adding either ABA alone or ABA and ZT together to the differentiation medium affected somatic embryogenesis. Our differentiation medium induced somatic embryos with a high frequency and was screened by counting the number of somatic embryos and observing their growth and development.【Result】 1) The addition of ABA to the medium showed positive effect on the induction and maturation of somatic embryos. 0.5-1.5 mg ·L -1 ABA in the medium accelerated the development of somatic embryos with largely normal morphology. When adding 2.0 - 2.5 mg ·L -1 ABA, the differentiation rate of somatic embryos increased significantly, but the proportion of abnormal embryos increased. After 30 days of treatment with low-concentration ABA, somatic embryos matured with an additional 2 weeks of culture in light. By contrast, on medium without ABA, somatic embryos were white and not fully matured with pale yellow cotyledon. 2) Adding ABA together with ZT to the medium significantly increased the differentiation rate and development of somatic embryos. Treatment with 2.0 mg ·L -1 ABA combined with 0.2-0.4 mg ·L -1 ZT induced somatic embryos with normal morphology, clearly showing green cotyledons and a radicle after 2 weeks light culture, while the growth and development of somatic embryos was noticeably slower without ZT treatment. Adding ZT concentration of higher than 0.6 mg ·L -1 inhibited growth and development of somatic embryos and was unfavorable to their induction and maturation.【Conclusion】 A differentiation medium containing 2.0 mg ·L -1 ABA and 0.2-0.4 mg ·L -1 ZT, significantly increases the efficiency of L. sino-americanum somatic embryogenesis and promotes normal development of somatic embryos.