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

倾斜的双子叶树种与针叶树种一样，表现出偏心生长和反作用木材的特征。但在被子植物中，反应木形成在学习茎的上侧，在解剖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变化，因为一些物种没有表现出明显的偏心和解剖特征，就像张力木材一样。在针叶树中，吲哚-3-乙酸(IAA)被认为是控制压缩木材形成的原因因素。但是，将这一概念应用于被子植物中形成的张力木肯定是困难的，因为倾斜茎的上侧的IAA浓度是否比下侧的IAA浓度在本质上变得更高是值得怀疑的。在本研究中，观察了三种双子叶乔木--白蜡树(Fraxinus S…)的茎的偏心生长和作为拉力木材的解剖特征更多的是Patiiana)、Mizunara(皱叶栎属)和Oobaasagara(Pterostirax Hispida)，人工倾斜。此外，还定量研究了倾斜茎两个部位的IAA和ABA水平的分布与张力材形成的关系。(1)倾斜后，两个树种SIOji和Mizunara表现出偏心生长，而Oobaasagara则不被识别。结果表明，有些物种的偏心率与偏心率的出现无关。(2)SIOji和Mizunara的倾斜茎具有张力木的解剖特征，而Oobaasagara则没有。在Sioji倾斜的茎的上部，用藏红牢牢绿色染色的切片观察到木质化的减少，但次生壁内侧没有发现胶状纤维，这是张力木的典型解剖特征。在Mizunara，木质部倾斜后形成的月牙形浅色记号证实了拉伸木材的形成，这是拉伸木材的一个特征，肉眼可以观察到。(3)Mizunara形成的典型张拉材倾斜后的IAA水平在上、侧、下三面无明显差异。可以认为，IAA在针叶树张紧材形成中的作用很小或很小，而对压紧材的形成有很强的作用。对于双子叶乔木，ABA可能是抗拉材形成的更重要物质，其定量分析结果将是令人期待的。较少

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