As Proteaceae subfamily Proteoideae are richly represented in the Cape Floristic Region of southern Africa and in south-western Australia, it is a convenient group for comparative studies of evolution and adaptation of plants in widely separated areas with a Mediterranean-type climate. Although species of Proteoideae attract considerable attention of researchers, the structural diversity of wood in this group remains under-explored. The wood structure of 51 species of 14 African and Australian genera of Proteoideae (Proteaceae) has been studied. These taxa are uniform in their wood structure; the diversity patterns are more related to plant stature, climatic factors and fire-survival strategies than to the taxonomy or phylogeny of the subfamily. Increases in length and diameter of fibres and diameter of pits in fibre walls are associated with a shift from a semi-arid winter-dry climate to a milder climate with winter rainfall. These trends may imply the transition from non-conducting imperforate tracheary elements to conducting elements in Mediterranean-type climatic regions. This presumable gain of hydraulic function of imperforate tracheary elements could be explained by adaptation to freeze–thaw stress during the late Quaternary, at least in the Cape Region. Vessel grouping shows no correlations with climatic factors. The seeders have a higher vessel frequency and narrower and lower rays than sprouters. We hypothesize that the larger rays in overground stems of sprouters serve as the sites of epicormic buds that provide for resprouting after fire or other damage. The occurrence of sclerified cells and/or irregularly arranged (occasionally circular) tracheary elements in broad rays of some species are thought to be responses to excessive sucrose transport in secondary phloem.

中文翻译：

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Proteoideae (Proteaceae) 树冠谱系的木材解剖：对无孔气管元件中边缘凹坑的进化和适应性价值的影响

由于 Proteaceae 亚科 Proteoideae 在南部非洲的开普植物区和澳大利亚西南部有丰富的代表性，它是比较研究在地中海型气候的广泛分离地区的植物进化和适应的方便组。尽管 Proteoideae 的物种引起了研究人员的极大关注，但该组中木材的结构多样性仍未得到充分探索。已经研究了 Proteoideae (Proteaceae) 的 14 个非洲和澳大利亚属的 51 个物种的木材结构。这些分类群的木结构是统一的；多样性模式更多地与植物高度、气候因素和火灾生存策略有关，而不是与亚科的分类学或系统发育有关。纤维长度和直径的增加以及纤维壁中凹坑直径的增加与从半干旱的冬季干燥气候向冬季降雨的温和气候的转变有关。这些趋势可能意味着地中海型气候区从非导电无孔气管元件向导电元件的转变。至少在开普地区，无孔气管元件的这种假定的水力功能增益可以通过适应晚第四纪的冻融应力来解释。船舶分组显示与气候因素没有相关性。播种机比发芽机具有更高的血管频率和更窄和更低的射线。我们假设发芽者地上茎中较大的射线可作为外生芽的位点，在火灾或其他损坏后提供重新发芽。