THE SIGNIFICANCE OF THE ACCESSORY TISSUES OF THE HYDROSYSTEM FOR OSMOTIC WATER SHIFTING AS THE 2ND PRINCIPLE OF WATER ASCENT, WITH SOME THOUGHTS CONCERNING THE EVOLUTION OF TREES
THE SIGNIFICANCE OF THE ACCESSORY TISSUES OF THE HYDROSYSTEM FOR OSMOTIC WATER SHIFTING AS THE 2ND PRINCIPLE OF WATER ASCENT, WITH SOME THOUGHTS CONCERNING THE EVOLUTION OF TREES
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DOI：
10.1163/22941932-90000414
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发表时间：
1984-01-01
期刊：
影响因子：
--
通讯作者：
BRAUN, HJ
中科院分区：
文献类型：
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作者：
BRAUN, HJ
水系的副组织包括木质部射线的薄壁接触组织、裸子植物的气管旁薄壁组织和被子植物的气管旁接触薄壁组织。裸子植物的副组织相对发育较差。在热带被子植物的木质部射线中，副组织以木质部射线接触组织和气管旁接触薄壁组织的形式广泛而高度发达。然而，在温带的木本被子植物中，副组织一般只很少存在。副组织在根上比在茎轴上更广泛地发育。热带落叶树的副组织与其他薄壁组织不同，总是不含淀粉，而且它们不断显示出高活性的酸性磷酸酶。温带落叶乔木的附属组织在冬季储存淀粉，但在春天，这些淀粉比其他薄壁组织的淀粉分解得早。淀粉的分解标志着酸性磷酸酶剧烈活动的开始。这种活动在春季的动员阶段（3月、4月）继续进行，然后随着叶子的冲洗突然停止。春季酸性磷酸酶的活性通常在根中比在树干中开始得早。木质部副组织的活动伴随着淀粉的分解和次生韧皮部酸性磷酸酶的活动。辅助组织中酸性磷酸酶的活性只出现在功能完备的导水血管附近。副组织的活动在树木中产生高渗透压。这带来了水的吸收，通常是正压力（系统压力），以及树木内部的渗透水转移。寒温带地区的木本植物在春季动员阶段进入树液，这是渗透吸水和水分转移的结果。在热带落叶乔木中，渗透水分吸收和水分转移似乎与蒸腾交替进行，这是一个全年的水分上升原理。对蕨类植物、裸子植物和被子植物的进化进行了讨论。
The accessory tissues of the hydrosystem consist of the parenchymatic contact tissue of the xylem rays, as well as the paratracheidal parenchyma in gymnosperms, and the paratracheal contact-parenchyma in angiosperms. In the gymnosperms the accessory tissues are relatively poorly developed. In the xylem rays of tropical angiosperms the accessory tissues can be extensive and highly developed in the form of contact tissue of the xylem rays and of the paratracheal contact-parenchyma. In the woody angiosperms of the temperate zone, however, the accessory tissues are in general only scantily present. The accessory tissues appear more extensively developed in the roots than in the shoot axes. The accessory tissues of tropical deciduous trees are, in contrast to the rest of the parenchyma, always free of starch, and they continually display a high activity of acid phosphatases. The accessory tissues of deciduous trees in the temperate zones store starch during the winter, but in the spring this starch is broken down earlier than that of the rest of the parenchyma. This breakdown of starch marks the beginning of an intense activity of acid phosphatases. This activity continues during the springtime mobilization phase (March, April), then ceases suddenly with the flushing of the leaves. The springtime activity of acid phosphatases usually begins earlier in the roots than in the trunk. The activity of the accessory tissues in the xylem is accompanied by a breakdown of starch and an activity of acid phosphatase in the secondary phloem. The activities of acid phosphatases in the accessory tissues only appear near water-conducting vessels which are fully functional. The activity of the accessory tissues produces a high osmotic pressure in the trees. This brings about an uptake of water, often a positive pressure (system pressure), and an osmotic water shifting within the tree. The woody plants of the cool-temperate climatic zones come into sap during the springtime mobilization phase as a result of this osmotic water uptake and water shifting. In tropical deciduous trees it seems that osmotic water uptake and water shifting is.sbd.in alternation with transpiration.sbd.a year-round principle of water ascent. Some thoughts concerning the evolution of pteridophyte, gymnosperm and angiosperm trees are discussed.