DERIVATION OF PRESSURE VOLUME CURVES BY A NONLINEAR-REGRESSION PROCEDURE AND DETERMINATION OF APOPLASTIC WATER
DERIVATION OF PRESSURE VOLUME CURVES BY A NONLINEAR-REGRESSION PROCEDURE AND DETERMINATION OF APOPLASTIC WATER
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DOI：
10.1093/jxb/42.2.159
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发表时间：
1991-02-01
影响因子：
6.9
通讯作者：
LOSCH, R
中科院分区：
文献类型：
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作者：
ANDERSEN, MN;JENSEN, CR;LOSCH, R
来自压力-体积（PV）分析的数据可以提交给转换I [即叶水势（psi-1）对相对含水量的倒数（1/R）]或转换II（即1/psi-1对R）。由于1/psi-1比所覆盖的范围相对较大，这可能导致误差结构的本质失真，特别是在变换II中。类似地，当通过线性回归从1 n psi-p和1/R的值导出弹性的敏感性因子（β）时，叶膨压势（psi-p）的对数变换可能扭曲误差结构。为了研究通过回归对PV分析得出的参数的失真效应的大小，将非线性回归程序与普通线性程序在从膨胀区的β和膨胀区和非膨胀区的叶渗透势（PSI-P）计算PSI-P时进行了比较。作为测试植物，我们使用田间生长的春大麦（Hordeum distichum L.，cvs Gunnar和Alis）。结果表明，变换和应用线性回归程序扭曲的误差结构的psi-p比的psi-pi的误差结构，这是只有轻微的影响。然而，我们建议在这两种情况下使用的非线性程序。此外，从PV分析，通过热电偶湿度测定法获得的活的和死的叶组织，分别，我们推导出计算质外体水分数（R（a））的数学基础。在R = 1时，R（a）为0.15，并随脱水而降低。
Data from pressure-volume (PV) analysis may be submitted to transformation I [i.e. leaf water potential (psi-1) versus inverse relative water content (1/R)] or to transformation II (i.e. 1/psi-1 versus R). This may cause an essential distortion of the error structure especially in transformation II due to the relatively large range which is to be covered by the 1/psi-1 ratio. Similarly, logarithmic transformation of leaf turgor potential (psi-p) when deriving the sensitivity factor of elasticity (beta) by linear regression from values of 1n psi-p and 1/R may distort the error structure. In order to investigate the magnitude of the distortion effect on parameters derived from PV analysis by regression a non-linear regression procedure was compared with the common linear procedure when calculating psi-p from beta in the turgid region and leaf osmotic potential (psi-p) in both the turgid and non-turgid region. As test plants we used field grown species of spring barley (Hordeum distichum L., cvs Gunnar and Alis). The results show that transformations and application of linear regression procedures distort the error structure of psi-p more than the error structure of psi-pi, which was only slightly affected. However, we recommend the use of the non-linear procedure in both cases.Furthermore, from PV analysis, obtained by thermocouple hygrometry on living and killed leaf tissue, respectively, we derived the mathematical basis for calculating the apoplastic water fraction (R(a)). R(a) was 0.15 at R = 1 and decreased with dehydration.The equations describing the relation between psi-pi and R and between psi-pi and R were extended to take into account the apoplastic water fraction.