- 期刊
- OpenAccess
台灣紅豆杉不同苗齡的微體繁殖與傾斜惰性的恢復
Micropropagation of Taxus Mairei Seedlings at Different Ages and Recoverability of Their Plagiotropic Shoots
摘要
以0.5年生台灣紅豆杉之頂芽、莖段進行培養，發現MS培養基添加0-5mg/l BA與活性碳的培養基最適合新芽發生，但沒有多芽體的產生。將BA濃度提高到20mg/l，可誘導多芽體產生，芽體發生率隨苗齡的增加而減少，但多芽數則隨苗齡的增加而增加，一個莖段培植體平均可產生7.4個芽體。將1.5-2cm芽體培養在1/2MS添加2.5mg/l IBA之培養基，可使60%的芽體發根。探討紅豆杉1.5年生苗，不同位置培植體的生長惰性，發現來自直立主幹上的頂芽與莖段均會維持原來的直立生長，而發育中的小側枝也可以100%恢復直立。來自側枝頂芽與莖段有31.7%與24.4%會恢復直立，其餘的芽體除了2.4-11.1%仍維持水平生長外，生長惰性也都會改善，惰性角度減少，而且再經過6個月的繼代培養，95%傾斜惰性的芽體都會恢復近於直立生長。
並列摘要
Shoot multiplication of shoot tip and stem explants derived from 0.5-yr-old Taxus mairei plants in vitro cultured in MS medium containing various combinations of plant growth regulators and different absorbents was tested. MS medium containing 0-5mg/l BA and activated charcoal promoted all explants to produced one elongating shoot. No multishoots occurred under this condition. Increasing BA concentrations up to 20mg/l in this medium induced multishoots not only from explants of 0.5-yr-old plants but also from explants of 1.0- and 1.5-yr-old plants. Explants from older plants produced a lower multiplication rate but more shoot numbers than did those from younger plants. Some explants from older plants could form 7.4 shoots per culture. About 60% of shoots 1.5-2cm tall rooted well when cultured in 1/2MS medium containing 2.5mg/l IBA. Topophysis of new shoots initiated from explants positioned at different parts of 1.5-yr-old seedling, including erect shoot tips and stems, developing short branches of less than 1cm long, and developed branch-shoot tips and stems, was investigated. New shoots from erect shoot tips and stems maintained their orthotropism, while those from branch explants showed none to various plagiotropic degrees. All developing branches could grow orthotropic shoots completely. The percentages of orthotropic shoots out of developed branch shoot tip and stem cultures were 31.7% and 24.4%, respectively. Most of the remaining cultures reduced their plagiotropism; only 2.4% and 11.1% of them still maintained their original plagiotropism. However, 95% of these plagiotropic shoots would be changed to nearly complete orthotropism after having been successively cultured for 6 months.