Institute for Systematic Botany and Ecology, Ulm University, Ulm, Germany.
New Phytol. 2011 Jan;189(1):218-28. doi: 10.1111/j.1469-8137.2010.03448.x. Epub 2010 Sep 14.
• The hydraulic conductance of angiosperm xylem has been suggested to vary with changes in sap solute concentrations because of intervessel pit properties. • The magnitude of the 'ionic effect' was linked with vessel and pit dimensions in 20 angiosperm species covering 13 families including six Lauraceae species. • A positive correlation was found between ionic effect and vessel grouping parameters, especially the portion of vessel walls in contact with neighbouring vessels. Species with intervessel contact fraction (F(C)) values < 0.1 showed an ionic effect between 2% and 17%, while species with F(C) values > 0.1 exhibited a response between 10% and 32%. The ionic effect increased linearly with the mean fraction of the total vessel wall area occupied by intervessel pits as well as with the intervessel contact length. However, no significant correlation occurred between the ionic effect and total intervessel pit membrane area per vessel, vessel diameter, vessel length, vessel wall area, and intervessel pit membrane thickness. • Quantitative vessel and pit characters are suggested to contribute to interspecific variation of the ionic effect, whereas chemical properties of intervessel pit membranes are likely to play an additional role.
• 由于导管间纹孔特性，被子植物木质部的水力传导率被认为会随树液溶质浓度的变化而变化。• 在包括六个樟科物种在内的 13 个科的 20 种被子植物中，导管和纹孔的尺寸与“离子效应”的大小相关。• 在具有导管间接触分数（F(C)）值<0.1 的物种中，离子效应在 2%到 17%之间，而在 F(C)值>0.1 的物种中，离子效应在 10%到 32%之间。离子效应与纹孔总面积中导管间纹孔所占的平均分数以及导管间接触长度呈线性关系增加。然而，离子效应与每根导管的总导管间纹孔膜面积、导管直径、导管长度、导管壁面积和导管间纹孔膜厚度之间没有显著相关性。• 定量的导管和纹孔特征被认为有助于离子效应的种间变异，而导管间纹孔膜的化学性质可能起到额外的作用。
