Study of the tolerance for low temperature of woody plants

木本植物耐低温能力的研究

基本信息

批准号：
13460063
负责人：
TANGE Takeshi
金额：
$ 9.47万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

In temperate evergreen tree species, lowering of the turgor loss point of shoot and of the osmotic potential at full turgor from autumn into winter have been well known. These changes in shoot water relations closely relate to the tolerance to low temperature and frost in winter. We tested a hypothesis that such seasonal change in shoot water relations is driven by root temperature by manipulating temperature of root and shoot of Cryptomeria japonica seedlings separately. In field condition, the lowering of the turgor loss point of shoot becomes clear when the temperature was under 5℃. This change in shoot water relations might represent adaptive responses to increased root hydraulic resistance at low temperature, when the viscosity of water was increased. The lowering of the turgor loss point was accelerated by root cooling and delayed by root warming. However, shoot warming did not give any effect on the shoot water relations under the low root temperature (<5℃) in winter. The change in shoot water relations by root cooling needed about 1 week and was reversible by warming of the seedling or the root. The lowering of the turgor loss point was driven much more by the increasing in cell wall elasticity than by the osmotic adjustment such as increase in sugar content. From these results, we clarified that the changes in the shoot water relations from autumn to winter was the response to the decrease of root (soil) temperature and the adaptive response to the winter cold. It was considered that frost injury of Cryptomeria japonica in late autumn and early spring was occurred under the condition when soil temperature was higher than 5℃.

在温度常绿的树种中，众所周知，从秋天到冬季，降低了芽的芽损失点和全胃中的渗透潜力。芽水关系的这些变化与冬季低温和霜冻的耐受性密切相关。我们检验了一个假设，即芽水关系的这种季节性变化是由根温度通过操纵根温度和japonica幼苗的芽的驱动的。在野外条件下，当温度低于5℃时，芽的较低损失点的降低变得清晰。当水的粘度增加时，芽水关系的这种变化可能代表了在低温下根部水解耐药性增加的自适应反应。较低的损失点的降低通过根冷却加速，并通过根变暖延迟。但是，在冬季，在低根温度（<5℃）下，射击温暖对芽水的关系没有任何影响。射击水关系通过根冷却所需的变化大约需要1周，并且通过播种或根的变暖是可逆的。与渗透调节相比，诸如糖含量的增加，较高的细胞壁弹性降低的降低要多得多。从这些结果中，我们澄清说，从秋天到冬季，芽水关系的变化是对根（土壤）温度降低以及对冬季寒冷的自适应反应的反应。据认为，在土壤温度高于5℃的情况下，秋天和早春发生了弗罗斯特·贾普尼卡（Cryptomeria Japonica）。