Functional consequences of stenophylly for leaf productivity: comparison of the anatomy and physiology of a rheophyte, Farfugium japonicum var. luchuence, and a related non-rheophyte, F. japonicum (Asteraceae)
Functional consequences of stenophylly for leaf productivity: comparison of the anatomy and physiology of a rheophyte, Farfugium japonicum var. luchuence, and a related non-rheophyte, F. japonicum (Asteraceae)
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DOI：
10.1007/s10265-006-0024-5
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发表时间：
2006-10
影响因子：
2.8
通讯作者：
Naofumi Nomura;H. Setoguchi;T. Takaso
中科院分区：
文献类型：
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作者：
Naofumi Nomura;H. Setoguchi;T. Takaso
本研究比较了海滨、林地和河岸三个不同种群的狭叶风沙生植物法夫根(Farfugium Japan onicum.Luchuence)的狭叶和非风沙生草的遮阳叶和遮阳叶的解剖和生理特性。光适应导致叶片变小，河岸适应导致叶片变窄(狭叶)。单位叶面积的光饱和光合作用速率(Pmax)与生境的光可利用性相对应。不考虑叶片大小，阳叶和阴叶的最大单位叶质量相似。而狭叶叶的最大质量显著低于阳叶和阴叶。这是因为叶肉细胞的数量和大小大于胞间CO2扩散所需的数量和大小，从而导致单位叶面积的叶质量更大。较高的细胞密度增加了叶肉细胞之间的接触，并增强了叶片的韧性。当水位上升时，风生植物的茎叶经常暴露在强烈的水流中，这表明物理压力引起的机械约束。
We investigated the anatomical and physiological characteristics of stenophyllous leaves of a rheophyte,Farfugium japonicumvar.luchuence, and sun and shade leaves of a non-rheophyte,F. japonicum, comparing three different populations from coastal, forest floor, and riparian habitats. Light adaptation resulted in smaller leaves, and riparian adaptation resulted in narrower leaves (stenophylly). The light-saturated rate of photosynthesis (Pmax) per unit leaf area corresponded to the light availability of the habitat. Irrespective of leaf size, thePmaxper unit leaf mass was similar for sun and shade leaves. However, thePmaxper mass of stenophyllous leaves was significantly lower than that of sun and shade leaves. This was because the number and size of mesophyll cells were greater than that required for intercellular CO2diffusion, which resulted in a larger leaf mass per unit leaf area. Higher cell density increases contact between mesophyll cells and enhances leaf toughness. Stenophyllous leaves of the rheophyte are frequently exposed to a strong water flow when the water level rises, suggesting a mechanical constraint caused by physical stress.