Gas Exchange Characteristics of the Invasive Species Mikania Micrantha and its Indigenous Congener M. Cordata (Asteraceae) in South China

華南入侵植物薇甘菊與其同屬本地種假澤蘭的氣體交換特性

鄧雄(Xiong Deng) ； 葉萬輝(Wan-Hui Ye) ； 馮惠玲(Hui-Ling Feng) ； 楊期和(Qi-He Yang) ； 曹洪麟(Hong-Ling Cao) ； 許凱揚(Kai-Yang Xu) ； 張雲(Yun Zhang)

《Botanical Bulletin of Academia Sinica》 45卷3期 (2004/07) Pp. 213-220

https://doi.org/10.7016/BBAS.200407.0213

摘要

研究了華南地區外來入侵種薇甘菊 Mikania micrantha H.B. Kunth 和它的本地同屬種假澤蘭 Mikania cordata (Burm.f.) B.L.Robinson的氣體交換特性。薇甘菊的 Rubisco活性 (V(下標 cmax))和電子傳遞速率 (J(下標 max))比假澤蘭更高，因而表現出更強的最大淨光合速率值 (A(下標 max))，表現出更強的光合能力。二者的光補償點、表觀量子產量(α)和暗呼吸(R(下標 d))無顯著差異，意味著它們具有相似的耐陰性。高A(下標 max)、光飽和點和CO2飽和點意味著薇甘菊比假澤蘭更易於適應強光環境和積累更多碳同化物。這些光合能力的差異可能是它們產生生態位分異的基礎。兩個種的葉性因數表現出以下的形式：本地種假澤蘭的構建成本(CC)和單位葉面積的氮含理比外來種薇甘菊更高，但葉重比(SLA)以及單位幹重的葉氮含量和光合氮利用率則顯著低於後者。薇甘菊較高的水分利用效率(WUE)和δ^13C值更可能歸功於其交強的光合能力而不是減小其氣孔導度，因而導致WUE和PNUE消長規律的喪失。

關鍵字

假澤蘭 ； 入侵種 ； 光合特性 ； 葉重比 ； 氮利用率

並列摘要

In South China, the photosynthetic characteristics of an invasive exotic weed Mikania micrantha H.B. Kunth and its indigenous close congener Mikania cordata (Burm. f.) B.L. Robinson were studied. Mikania micrantha exhibited a greater biochemical capacity for photosynthesis than M. cordata, as the former had higher V(subscript cmax) and J(subscript max), which lead to its higher maximum assimilation rate A(subscript max) values. Similar light compensation point, apparent quantum yield (α), and dark respiration (R(subscript d)), suggested a similar shade-tolerance. Higher A(subscript max), light saturating point, and CO2 saturating point give M. micrantha greater potential to acclimate to brighter environments and a larger pool of available carbon. These differences in photosynthetic characteristics could be a basis for their niche partitioning. The leaf traits of the native and invasive Mikania species were as follows; higher construction cost (CC), lower specific leaf area (SLA), as well as lower mass-based leaf N and photosynthetic nitrogen-use efficiency (PNUE) for the native species, but M. micrantha had lower area-based leaf N. The higher water use efficiency (WUE) and δ^13C observed in M.micrantha was probably due to its high photosynthetic capacity and not to reduced stomatal conductance, explaining the absence of any trade-off between WUE and PNUE.

並列關鍵字

Invasive species ； Mikania ； Nitrogen use efficiency ； Photosynthetic characteristics ； Specific leaf area