台灣穗花杉扦插、高壓及種子繁殖與苗木生長

Propagation and Growth of Amentotaxus formosana by Stem Cutting, Air-Layering, and Seeds

鍾振德(Jeng-Der Chung) ； 簡慶德(Ching-Te Chien) ； 陳建帆(Chien-Fan Chen) ； 陳正豐(Cheng-Fong Chen) ； 林則桐(Tzer-Tong Lin)

《台灣林業科學》 34卷3期 (2019/09) Pp. 155-168

https://doi.org/10.7075/TJFS.201909_34(3).0002

摘要

台灣穗花杉（Amentotaxus formosana Li）僅分布於台灣南部，由於族群稀少，被列為積極保育之本土樹種。台灣穗花杉有性生殖能力薄弱，種子產量少，原生地多行萌芽更新，成為族群拓展最大的限制因子。本研究探討台灣穗花杉扦插與高壓繁殖方法，並利用環狀剝皮誘導開花結種子，培育實生苗，最後比較扦插、高壓與實生苗的生長，以作為後續復育之基石。台灣穗花杉最適扦插時間是在10～11月芽休眠時期，發根時間需5～6個月，61株母樹間枝條扦插發根率13～100%。從11株台灣穗花杉13年生扦插林木進行高壓處理，發根率以3月後樹液流動芽綻放時較佳，於7月達到最高89～100％。扦插或高壓處理之發根率，不同母樹間有很大的差異。台灣穗花杉扦插育苗2年後之成苗率低於10%，而高壓育苗4.5年後之成苗率82%，種子育苗1.6年後之成苗率57.9%。台灣穗花杉於6月中旬，利用高壓環剝處理容易誘導花芽分化，開花比率約40%，每株雄毬花數量1.5～5.0個，雌毬花數量1.0～10.8個，且不同營養系間雌雄花數量沒有顯著差異。經高壓環剝之發根枝條栽種後經人工輔助授粉，平均每株最多僅2.7個飽滿種子。台灣穗花杉小苗栽種初期生長緩慢，扦插苗年生長高度小於5cm，實生苗年生長高度7.3cm，然高壓苗木年生長高度大於10cm，顯示高壓苗成長幅度優於實生苗和扦插苗，原因是實生苗與扦插苗培育初期每年僅抽芽1次，但高壓苗則每年抽芽2次，芽體的萌發次數影響其生長速度。

關鍵字

台灣穗花杉 ； 開花 ； 生長 ； 高壓 ； 種子苗 ； 扦插

並列摘要

Amentotaxus formosana Li is endemic to southern Taiwan. Due to a small limited population, this species had been conserved and protected. Seeds of A. formosana in its natural habitat are very few, and natural generation by sprouting from basal stems was investigated. In this paper, stem cutting and air layering techniques were used for vegetative propagation, and the growth of rooted cuttings and air-layered twigs was measured. Further, seeds collected from air-layered plants were germinated, and seedling growth was measured. A suitable time for stem cutting of A. formosana was in October and November when bud dormancy began, and rooting percentages from 61 mother trees were 13~100% within 6 mo. In 11 trees selected from 13-yr-old stem-cut trees and used for air-layering treatment, rooting percentages increased in late March when tree sap began to flow and further increased to high percentages of 89~100% in mid-July. There were great differences in rooting percentages among mother trees treated with stem cutting and air-layering. Rooted cuttings did not grow well, and ＞ 90% died after 2 yr of cultivation in a nursery, but rooted small trees from air-layering grew well, and the survival percentage was 82% after 4.5 yr of cultivation, while the survival percentage of seedlings from seeds was 57.9% after 1.6 yr of cultivation. Air-layered rooted twigs of A. formosana were planted in pods, and bud differentiation was induced in June; the flowering percentage in all the planted trees was about 40%. However, the number of male flowers per tree ranged 1.5~5.0 and that of female flowers was 1.0~10.8. Further, by hand pollination, the maximum number of filled seeds per tree was 2.7 seeds. Rooted cuttings grew slowly, and the annual average height was ＜ 5 cm, while the annual average height of seedlings from seeds was 7.3 cm. However, the annual average height of rooted air-layer trees exceeded 10 cm due to budding twice a year: vegetative buds first followed by reproductive buds.

並列關鍵字

Amentotaxus formosana Li ； flowering ； growth ； air-layering ； seedling ； stem cutting