Hydraulic efficiency of the leaf venation system in sun- and shade-adapted species
Hydraulic efficiency of the leaf venation system in sun- and shade-adapted species
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DOI：
10.1071/fp05100
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发表时间：
2005-01-01
影响因子：
3
通讯作者：
Salleo, S
中科院分区：
文献类型：
--
作者：
Nardini, A;Gortan, E;Salleo, S
我们验证了叶片水力学与不同植物对光的适应相关的假设，特别是叶片脉序(R脉序)的水力阻力在阳光适应的物种中比在遮荫适应的物种中要低。用高压流量计(HPFM)测量了6种日照和6种遮荫植物的R-脉序。计数中肋近端1/3处的导管数目，测量最宽导管的直径和静脉密度。遮荫树种的R-脉序高于阳生树种，且与最宽导管的平均直径呈负相关。不同树种的最大水汽导度与相应的R脉呈负相关。适应阳光的物种似乎已经发展出一种高效的传导系统，为活的叶肉细胞提供水分，以应对阳光充足的栖息地典型的高水分需求。相比之下，适应阴凉生境的物种表现出更高的R-脉络值，这是因为它们在叶片中产生宽管道所需的碳投资较低。
We tested the hypothesis that leaf hydraulics is correlated with the light adaptation of different plant species and specifically that the hydraulic resistance of the leaf venation (R-venation) is lower in sun-than in shade-adapted species. R-venation was measured in six sun- and six shade-adapted species with a high-pressure flow meter (HPFM). The number of conduits at the proximal third of the midrib was counted and the diameter of the widest conduits together with vein density were measured. R-venation was higher in shade species than in sun species and it was negatively correlated with the mean diameter of the widest conduits. Maximum leaf conductance to water vapour recorded for the different species was negatively correlated with the corresponding R-venation. Sun-adapted species coping with the high water demand typical of sunny habitats appeared to have developed a highly efficient conducting system to supply living mesophyll cells with water. In contrast, species adapted to shady habitats showed higher R-venation values according to their lower need for investment of carbon into producing wide conduits in the leaf.