Altitudinal Variation of Resin Ducts in Pinus Taiwanensis Hayata (Pinaceae) Needles

台灣二葉松針葉內松脂管之海拔變異

許秋容(Chiou-Rong Sheue) ； 楊遠波(Yuen-Po Yang) ； 黃玲瓏(Ling-Long Kuo-Huang)

《Botanical Bulletin of Academia Sinica》 44卷4期 (2003/10) Pp. 305-313

https://doi.org/10.7016/BBAS.200310.0305

摘要

本研究以生長於台灣中部海拔700至3,100公尺的台灣二葉松為材料，針對其針葉內的松脂管變異進行首次探討，包括位置型、數目、大小、排列型和解剖結構等。葉肉內可發現中生、邊生及交截型之初生松脂管，且同一針葉內的松脂管即為此三種型的混合。交截型松脂管的數目隨著海拔的升高呈明顯遞減；而中海拔地區的針葉內比低海拔和高海拔者有較多的中生型松脂管。葉肉組織內的松脂管數為3-7個，本特徵依不同海拔高度之變化而表現出顯著差異，以中海拔之針葉內具最多的松脂管，海拔3,100公尺者為次之，而海拔700公尺的為最少。葉肉中的松脂管可區分為八個排列型（基本型和型I-VII），多數呈I-IV型。另發現一種相當罕見的次生松脂管位維管束組織內，且其中現頻度依海拔升高而明顯遞減。生長於台灣的台灣二葉松其針葉內的松脂管均為中生、邊生及交截型之混合，和中國大陸所稱僅具中生型松脂管之台灣二葉松明顯不同，可惜以往均未被分類學者所辨識，此特徵和其他之形態特徵實是未來分類處理之重要參卓。

關鍵字

海拔變異 ； 針葉 ； 松脂管 ； 台灣二葉松

並列摘要

The variation of resin ducts in needles of Pinus taiwanensis along an altitude gradient (700 m- 3,100 m) in central Taiwan is revealed for the first time in this study, including position type, number, size, arrangement pattern and anatomical structural variation. Three types of resin ducts-medial, external and septal-were found according to their relative positions in the mesophyll. All needles sampled showed combinations of these three resin duct types. Mostly, 3-7 resin ducts were found in the mesophyll per needle, and the number of resin ducts was significantly greater at mid altitudes than at high and low altitudes. Septal ducts decreased in number with an increase in altitude; however, needles from mid altitudes had more external ducts. Eight patterns (basic and patterns I-VII) of resin ducts in the mesophyll of needles were delineated to present the arrangement variations. In addition to the primary ducts found in the mesophyll, we found the rare bundle sheath ducts in some needles, and their frequencies decreased obviously with an increase in altitude. The consistent combination feature of medial, external, and septal ducts in needles of P. taiwanensis from Taiwan could be easily distinguished from those with medial ducts from mainland China. However, this difference has unrecognized before, and it should be considered in future taxonomic work.

並列關鍵字

Altitudinal variation ； Needle ； Resin duct ； Pinus taiwanensis