目标:近年来,相当多的努力集中在将木材解剖学和关键生态特征联系起来。分析大型数据库的研究描述了这些生态特征如何随着与传导和支持相关的木材解剖特征而变化。但没有考虑这些功能如何与参与水和碳水化合物储存的细胞(即薄壁组织细胞)相互作用。
方法:我们分析了,在系统发育的背景下,执行三种木质部功能中每一种功能的细胞类型之间的功能关系(传导,支撑和储存)和木材密度和理论电导率,使用大约的样品。800种来自中国。
结果:轴向实质和射线具有不同的进化相关模式。在高传导能力和大量轴向薄壁组织之间发现了进化联系,这可能与储水能力和栓塞修复有关。而大量的射线组织随着机械支撑的增加和水力能力的降低而进化。在系统发育主成分分析中,轴向薄壁组织与传导能力增加以及射线与木材密度的这种关联代表了正交的变化轴。在多变量空间中,然而,射线的比例可能与电导呈正相关,与木材密度呈负相关,表明这些轴在具有宽射线的物种中的灵活性。
结论:研究结果表明,薄壁组织类型可能在功能上有所不同。不同细胞类型代表的功能轴在谱系之间是保守的,表明在被子植物的生态策略中具有重要作用。
OBJECTIVE: In recent years considerable effort has focused on linking wood anatomy and key ecological traits. Studies analysing large databases have described how these ecological traits vary as a function of wood anatomical traits related to conduction and support, but have not considered how these functions interact with cells involved in storage of water and carbohydrates (i.e.
parenchyma cells).
METHODS: We analyzed, in a phylogenetic context, the functional relationship between cell types performing each of the three xylem functions (conduction, support and storage) and wood density and theoretical conductivity using a sample of approx. 800 tree species from
China.
RESULTS: Axial
parenchyma and rays had distinct evolutionary correlation patterns. An evolutionary link was found between high conduction capacity and larger amounts of axial
parenchyma that is probably related to water storage capacity and embolism repair, while larger amounts of ray tissue have evolved with increased mechanical support and reduced hydraulic capacity. In a phylogenetic principal component analysis this association of axial parenchyma with increased conduction capacity and rays with wood density represented orthogonal axes of variation. In multivariate space, however, the proportion of rays might be positively associated with conductance and negatively with wood density, indicating flexibility in these axes in species with wide rays.
CONCLUSIONS: The findings suggest that
parenchyma types may differ in function. The functional axes represented by different cell types were conserved across lineages, suggesting a significant role in the ecological strategies of the angiosperms.