Errors Arising From Rapid Water Loss in the Measurement of Leaf Water Potential by the Pressure Chamber Technique
Errors Arising From Rapid Water Loss in the Measurement of Leaf Water Potential by the Pressure Chamber Technique
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DOI：
10.1071/pp9800527
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
N. Turner;M. J. Long
中科院分区：
文献类型：
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作者：
N. Turner;M. J. Long
在快速蒸腾的叶片中，在压力室中测量的未覆盖的叶片的水势比用塑料鞘覆盖的叶片的水势低0.2- 0.7MPa，从刚被切除之前到测量完成。未覆盖叶片的水势误差是由于切除后前30 s内水分快速流失造成的。水势降低的程度取决于蒸腾速率、切除时的叶水势、物种以及植物是否生长在温室或田间。有人建议，物种之间的变化和温室生长和田间生长的植物之间产生的植物组织的保水特性的差异，以及在切除的蒸腾速率的差异。在叶水势的昼夜变化的快速失水引起的误差的大小证明和膨压势的计算和水流过植物的阻力的误差的影响进行了讨论。
In rapidly transpiring leaves, the water potentials of uncovered leaves measured in a pressure chamber were 0.2-0.7 MPa lower than the water potentials of leaves that were covered with a plastic sheath from just prior to their excision to the completion of the measurement. The error in the water potential of uncovered leaves arose from rapid water loss in the first 30 s after excision. The degree to which the water potentials were lowered depended on the rate of transpiration, the leaf water potential at the time of excision, the species, and whether the plants were grown in the glasshouse or field. It is suggested that the variation between species and between glasshouse-grown and field-grown plants arises from differences in water retention characteristics of plant tissue as well as to differences in the rates of transpiration at excision. The size of the error induced by the rapid water loss on diurnal changes in leaf water potential is demonstrated and the effect of the error in the calculation of turgor potentials and in the resistances to water flow through the plant is discussed.