Comparison between two methods of generating pressure—volume curves
Comparison between two methods of generating pressure—volume curves
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两种压力-体积曲线生成方法的比较
DOI：
10.1111/j.1365-3040.1985.tb01208.x
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发表时间：
1985
影响因子：
7.3
通讯作者：
J. R. Roden
中科院分区：
文献类型：
--
作者：
G. Ritchie;J. R. Roden
抽象的。使用两种程序在沿海花旗松 [Pseudotsuga menziesii (Mirb.) Franco] 幼苗的根和芽上生成压力-体积 (PV) 曲线。在第一种方法（方法 A）中，样品在压力室内脱水。收集渗出的茎汁液并在连续压力增加时称重以得出PV曲线。在第二种方法（方法B）中。切除的样品通过蒸散作用在压力室外干燥。定期称重以确定汁液损失，并在压力室中确定其相应的平衡压力，以得出 PV 曲线。
从 P-V 曲线以图形方式导出的全膨胀时体积平均渗透势和零膨胀时水势的估计值对于每种方法都是不同的。一般来说，方法 A 的估计结果更为负面，在一种情况下高达 1.5 MPa。此外，方法 B 没有记录遭受严重水分胁迫的幼苗的渗透调节，而方法 A 则记录了这一情况。
Abstract. Pressure—volume (P—V) curves were generated on roots and shoots of coastal Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings using two procedures. In the first (Method A), samples were dehydrated inside a pressure chamber. Exuded stem sap was collected and weighed at successive pressure increases to derive the P—V curve. In the second method (Method B). excised samples were allowed to dry outside the pressure chamber by evapotranspiration. They were weighed periodically to determine sap loss and their corresponding balance pressures were determined in a pressure chamber in order to derive the P—V curve.
Estimates of volume averaged osmotic potential at full turgor and water potential at zero turgor which were derived graphically from the P—V curves, were different for each method. In general, estimates were more negative in Method A, by as much as 1.5 MPa in one case. Also, Method B did not record an osmotic adjustment in seedlings which were subjected to severe water stress while Method A did.