著生杜鵑之微體繁殖

In vitro Micropropagation of Rhododendron kawakamii Hay.

何雅齡(Ya-Ling Ho) ； 廖宇賡(Yue-Ken Liao)

《台灣林業科學》 35卷2期 (2020/06) Pp. 161-172

https://doi.org/10.7075/TJFS.202006_35(2).0004

摘要

本研究以植物組織培養技術建立臺灣原生著生杜鵑（Rhododendron kawakamii Hay.）大量繁殖之方法。以著生杜鵑成熟種子經無菌消毒並播種，生長6-8 wk後，取無菌苗頂芽作為培植體，培養於含有1.07～34.4 μM 6- （γ-γ-dimethylallylamino） purine （2iP）之1/2 Anderson培養基中24 wk，結果顯示以17.2 μM 2iP處理者可獲得最高芽體數（533.8個），將叢生小芽體接續繼代到含有較低濃度（4.3～8.6 μM）2iP之培養基中促進生長。將培養8 wk後的叢生芽團整塊未切移入添加有0～2 μM indole-3-butyric acid（IBA）的洋菜培養基中誘導發根，可獲得短根、長根及叢根等不同根形態。調查單一小苗之發根率，顯示以1～2 μM IBA處理發根率最高（＞97.5%），且有超過80%屬於長根及叢根。將具有不同形態根系之小苗移出瓶外種植，三種形態根系小苗其馴化成活率均達95%以上，這些小苗在溫室培養1年後苗高可達8 cm。本研究使用少量種子建立著生杜鵑組織培養繁殖方法，在繁殖材料採集不易情形下，利用此法可於短時間內生產大量種苗作為復育之用。

關鍵字

馴化 ； 杜鵑 ； 發根 ； 芽體增殖

並列摘要

Plant tissue culture techniques were used for the mass propagation of the native Taiwanese azalea, Rhododendron kawakamii Hay., in this study. Apical shoots of 6~8-wk-old in vitro seedlings derived from mature seeds of R. kawakamii were collected as explants for shoot proliferation. Explants, cultured for 24 wk, were incubated in a 1/2 Anderson medium containing 1.07~34.4 6-(γ-γ-dimethylallylamino) purine (2iP) to induce shoots. The highest shoot production (533.8 shoots explant-1) was obtained from medium supplemented with 17.2 μM 2iP. Shoot elongation was enhanced in media containing lower levels of 2iP (4.3~8.6 μM) with 8 wk of culturing. Multiple shoots in clumps obtained from the shoot elongation stage were subcultured as 1 unit without separation in agar medium supplemented with 0~2 μM indole-3-butyric acid (IBA) for root induction. Various types of adventitious roots including short, long and cluster-rooted types were observed in rooting culture. The highest rooting percentages (＞ 97.5%) were observed in media containing 1~2 μM IBA, among which over 80% were of the long and clustered types of roots. High survival rates (＞ 95%) were obtained from explants with various types of roots after acclimatization. Plants of 8 cm in height were obtained after 1 yr of cultivation in a greenhouse. In the present study, an in vitro propagation protocol was successfully established using limited seeds for indigenous R. kawakamii which is rare in Taiwan nowadays and difficult to collect in the field.

並列關鍵字

acclimatization ； azalea ； rooting ； shoot proliferation