Hydraulic Properties of Pine and Bean Roots With Varying Degrees of Suberization, Vascular Differentiation and Mycorrhizal Infection.
Hydraulic Properties of Pine and Bean Roots With Varying Degrees of Suberization, Vascular Differentiation and Mycorrhizal Infection.
复制标题
不同程度木栓化、维管束分化和菌根感染的松树和豆根的水力特性。
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
Cpp Reid
中科院分区：
文献类型：
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作者：
R. Sands;E. Fiscus;Cpp Reid
火炬松幼苗根系的水力行为符合Fiscus（1975）和道尔顿等（1975）的模型。单位根表面积的平均导水率为1.4 × 10-6 cm s-1 bar-1。采用断根法测定了松树根系不同部位的导水率。棕色（老栓化）根的平均导水率为7.55 × 10-7 cm s-1 bar-1，白色（新再生的未栓化）根的平均导水率为1.95 × 10-6 cm s-1 bar-1。导水率是独立的菌根感染量。在零静水压力差下，去顶幼苗的平均最大渗出速率为1.31 × 10-7 cm·s-1。在25°C下测定了菜豆和火炬松幼苗根系营养液的轴向传导率。豆导管和松树管胞进行了0.4和0.55倍的理想Poietville电导。具有分化导管的菜豆根单位面积的中轴导是松树根的8倍，是具有未分化导管的菜豆根的6.5倍。菜豆根轴向电导随温度的变化完全可以用溶液粘度的变化来解释。在测量整个根系水力传导的实验中，轴向阻力可以忽略不计。
The hydraulic behaviour of root systems of loblolly pine seedlings conformed to the model of Fiscus (1975) and Dalton et al. (1975). The average hydraulic conductance per unit of root surface area was 1.4 × 10-6 cm s-1 bar-1. The hydraulic conductance of various parts of pine root systems was determined using root severing experiments. The average hydraulic conductance of brown (older suberized) roots was 7.55 × 10-7 cm s-1 bar-1, and that of white (newly regenerated unsuberized) roots was 1.95 x 10-6 cm s-1 bar-1. Hydraulic conductance was independent of the amount of mycorrhizal infection. The mean maximum exudation rate from detopped seedlings at zero hydrostatic pressure difference was 1.31 × 10-7 cm s-1. Axial conductance of nutrient solution by roots of bean plants and loblolly pine seedlings was measured at 25°C. Bean vessels and pine tracheids conducted at 0.4 and 0.55 times idealized Poiseuille conductance. Bean roots with differentiated vessels had 8 times more axial conductance per unit area of stele than pine roots, and 6.5 times more axial conductance than bean roots with undifferentiated vessels. Change in axial conductance of bean roots with temperature was completely explained by change in viscosity of the solution. Axial resistance was negligible in the experiments where the hydraulic conductance of whole root systems was measured.