Efficient and new method for Tectona grandis in vitro regeneration

Abstract The aim of this study was to develop a shoot regeneration protocol for Tectona grandis by examining the effects of pretreatments, regeneration culture medium, adventitious rooting, and acclimatization. The best organogenic potential was achieved when hypocotyls and cotyledonary segments from seedlings germinated on a medium containing TDZ, were cultured for four weeks on MS medium supplemented with BAP/GA3. With TDZ pretreatment during seed germination, up to 70% of the cotyledonary segments (0.5 TDZ pretreatment and 1.0 BAP + 0.5 GA3 during regeneration, mg L-1) and 60% of the hypocotyl explants (0.1 TDZ pretreatment and 1.0 BAP + 0.5 GA3 during regeneration, mg L-1) resulted in shoot regeneration. Finally, 65% of the regenerated shoots rooted, of which 60% were successfully acclimatized ex vitro. Our protocol increases regeneration efficiency for teak and it can serve as a platform for genetic transformation to improve this important tree species.

摘要 本研究旨在通过考察预处理、再生培养基、不定根诱导及驯化培养对柚木（Tectona grandis）的影响，建立其高效芽再生体系。当使用在添加噻苯隆（TDZ）的培养基上萌发的实生苗的下胚轴与子叶切段，在添加苄氨基嘌呤（BAP）/赤霉素3（GA3）的MS培养基上培养4周时，可获得最佳器官发生潜能。若在种子萌发阶段采用TDZ预处理，子叶切段（萌发阶段TDZ浓度为0.5 mg·L⁻¹，再生阶段培养基添加1.0 mg·L⁻¹ BAP + 0.5 mg·L⁻¹ GA3）的芽再生率最高可达70%；下胚轴外植体（萌发阶段TDZ浓度为0.1 mg·L⁻¹，再生阶段培养基添加1.0 mg·L⁻¹ BAP + 0.5 mg·L⁻¹ GA3）的芽再生率可达60%。最终，再生芽的生根率达65%，其中60%可成功完成室外驯化炼苗。本研究建立的再生体系提升了柚木的再生效率，可作为该重要林木树种遗传转化改良的技术平台。