Distribution of IAA and ABA Levels and Reaction Wood Formation in Inclined Stems of Angiosperm Trees

倾斜双子叶树木与针叶树一样具有偏心生长和反应木的特征。而被子植物的反应木形成于学习茎的上侧，在解剖学上表现出与裸子植物不同的特征。此外，倾斜的树木并不总是表现出明显的张力木材的变化，因为一些物种没有显着的偏心和解剖特征的张力木材。在针叶树中，吲哚-3-乙酸（IAA）的作用已被假定和理解为控制压缩木材形成的因果因素。但是，这一概念应用于被子植物中形成的拉伸木材一定是困难的，因为它是值得怀疑的IAA浓度是否在倾斜的茎的上侧比下侧更高。本研究观察了三种双子叶树木的偏心生长现象和张力木的解剖特征 ...更多信息 paethiana）、水曲柳（Quercus crispula）和卵叶树（Pterostyrax hispida），人工倾斜。此外，IAA和脱落酸（阿坝）水平的分布进行了定量研究，在两个位置的倾斜茎，与张力木材的形成。(1)虽然有两个种，sioji和mizunara，倾斜后表现出偏心生长，在oobaasagara这是不承认的。证实了有些种的倾斜度与偏心率的出现无关。(2)细枝和水奈良的倾斜茎具有张力木的解剖学特征，而大笠原的倾斜茎则没有。在斜茎的上部，经番红-固绿染色的切片观察证实木质化减少，但次生壁内部没有发现典型的抗拉材解剖特征的胶质纤维。在水原中，通过在倾斜后形成的木质部中出现能够用肉眼观察到的新月形和浅色标记，作为张力木材的特征，确认了张力木材的形成。(3)水原倾斜后形成的典型抗拉材中IAA含量在上、侧、下侧之间没有明显差异。可以认为，IAA对针叶树抗拉材的形成作用不大或很小，而对压缩材的形成作用较大。在双子叶树种中，阿坝可能是形成抗拉材的重要物质，定量分析结果令人期待。少

Inclined dicotyledonous trees show characteristics of eccentric growth and reaction wood in common with coniferous trees. But in case of angiosperm trees, the reaction wood is formed on upper side of learning stem, and it exhibits anatomically different features from gymnosperms. Additionally, leaning trees do not always exhibit pronounced changes of tension wood, because some species show no marked eccentric and anatomical features as tension wood. In conifers the role of indole-3-acetic acid (IAA) has been postulated and understood as causal factors in controlling the formation of compression wood. But application of the concept to tension wood formed in angiosperms must be difficult, because it is questionable whether IAA concentration becomes higher in nature on upper side of inclined stem than lower side. In this study, appearances of eccentric growth and anatomical features as tension wood were, observed throughout stems in three species of dicotyledonous trees, sioji (Fraxinus s … More paethiana), mizunara (Quercus crispula) and oobaasagara (Pterostyrax hispida), inclined artificially. Furthermore, distribution of IAA and abscisic acid (ABA) levels were quantitatively examined on two positions of leaning stems, in relation to formation of tension wood.(1) Although two species, sioji and mizunara, exhibited eccentric growth after inclination, in oobaasagara it was not recognized. It was substantiated that there are some species which the inclination was not associated with appearance of eccentricity. (2) Anatomical features as tension wood were recognized in leaning stems of sioji and mizunara, but not oobaasagara. On upper side in inclined stems of sioji, reduction of lignification was confirmed by observing sections stained with safranine-fastgreen, though the gelatinous fibers were not found the inside of secondary walls which was anatomically typical features of tension wood. In mizunara the formation of tension wood was confirmed by appearance of crescent-shaped and light colored marks in xylem formed after inclination which was able to observe with the naked eye, as a feature of tension wood. (3) IAA levels examined in mizunara forming typical tension wood after inclination exhibited no apparent differences among upper, lateral and lower sides. It may be considered that IAA has little or a little role in tension-wood formation, whereas it effects strongly on compression-wood formation in conifers. In case of dicotyledonous trees, ABA may be more important substance for formation of tension wood, and the result of the quantitative analysis will be expected. Less