Relationships between photosynthesis, nitrogen and leaf structure in 14 grass species and their dependence on the basis of expression
Relationships between photosynthesis, nitrogen and leaf structure in 14 grass species and their dependence on the basis of expression
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DOI：
10.1046/j.1469-8137.1999.00426.x
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发表时间：
1999-07-01
期刊：
影响因子：
9.4
通讯作者：
Sonié, L
中科院分区：
文献类型：
--
作者：
Garnier, E;Salager, JL;Sonié, L
在室内非限制营养条件下，研究了14种牧草叶片结构、氮素浓度与CO2同化率(A)的关系。结构特征包括叶片厚度和密度，以及不同类型组织(叶肉、表皮、维管束和厚壁组织)所占叶体积的比例。评估了单位叶面积和鲜重表示的数据之间的关系。后者与叶体积密切相关，可以用单位叶鲜重A(Fm)代替单位叶体积A。单位叶面积同化率(A(A))与叶片厚度和单位叶面积叶肉细胞数呈正相关，与单位面积叶片含氮量的关系不显著。A(Fm)与叶片厚度呈负相关，与鲜叶有机氮浓度呈正相关。涉及这两个变量的多元回归解释了A(Fm)中81%的方差。A值(Fm)也与叶肉细胞在叶体积中的比例显著相关，但令人惊讶的是，这种相关性是负的。这是因为具有高A(Fm)和氮浓度的薄叶具有比厚叶更多的机械支持组织；因此，它们的叶肉比例也较低。这些数据表明，除了叶片氮，叶片厚度对所研究的草种的二氧化碳同化速率也有很大的影响。
The relationships between leaf structure, nitrogen concentration and CO2 assimilation rate (A) were studied far 14 grass species grown in the laboratory under non-limiting nutrient conditions. Structural features included leaf thickness and density, and the proportion of leaf volume occupied by different types of tissue (mesophyll, epidermis, vessels and sclerenchyma). Relationships were assessed for data expressed per unit leaf area and fresh mass. The latter was found to be closely related to leaf volume, which allowed us to use A per unit leaf fresh mass (A(fm)) as a surrogate of A per unit leaf volume. Assimilation rate per unit leaf area (A(a)) was positively correlated with leaf thickness and with the amount of mesophyll per unit leaf area; the relationship with leaf nitrogen content per unit area was only marginally significant. A(fm) was negatively correlated with leaf thickness and positively with fresh mass-based leaf organic nitrogen concentration. A multiple regression involving these two variables explained 81 %, of the variance in A(fm). The value of A(fm) was also significantly related to the proportion of mesophyll in the leaf volume, but surprisingly the correlation was negative. This was because thin leaves with high A(fm) and nitrogen concentration had proportionally more mechanically supportive tissues than thick ones; as a consequence, they also had a lower proportion of mesophyll. These data suggest that, in addition to leaf nitrogen, leaf thickness has a strong impact on CO2 assimilation rate for the grass species studied.