Department of Biology, University of New Mexico, 87131, Albuquerque, New Mexico.
J Chem Ecol. 1993 Jul;19(7):1429-37. doi: 10.1007/BF00984887.
The correlation between total phenolics and tannin content within a species is often considered to be suitably strong to allow researchers to assume, with some degree of confidence, that levels of one will approximately parallel the other. However, the manipulation of resource availability could lead to disproportionate changes in total phenolics and tannins and/or in the specific monomers of which these fractions are composed, thus altering the correlation between these components. In order to test this hypothesis, we examined the correlation between foliar levels of total phenolics (as measured by the ferric chloride assay) and tannins (as measured by an astringency assay) in Douglas-fir (Pseudotsuga menziesii Mirb. Franco) before and after the manipulation of nitrogen and water availability. Prior to manipulation of resources, the correlation between total phenolics and tannins was strong and highly significant (r(2)=0.869;P < 0.001). This correlation was considerably weaker and not statistically significant following resource manipulation (r(2) = 0.392; 0.20 <P < 0.50). These results demonstrate that manipulation of resource availability can alter the correlation between total phenolics and tannins in intraspecific comparisons. The causes underlying the observed degradation in the correlation between these measures (whether qualitative, quantitative, or both) are unknown and require further investigation.
在同一物种中，总酚类物质和单宁含量之间的相关性通常被认为是足够强的，以至于研究人员可以有一定程度的信心假设，一种物质的水平大致上与另一种物质的水平平行。然而，资源可用性的操纵可能导致总酚类物质和单宁类物质以及它们组成的特定单体之间不成比例的变化，从而改变这些成分之间的相关性。为了检验这一假设，我们在操纵氮和水分供应之前和之后，检查了花旗松（Pseudotsuga menziesii Mirb. Franco）叶片中总酚类物质（用氯化铁测定法测定）和单宁类物质（用收敛性测定法测定）之间的相关性。在资源操纵之前，总酚类物质和单宁类物质之间的相关性很强且高度显著（r(2)=0.869；P<0.001）。在资源操纵之后，这种相关性要弱得多，且不具有统计学意义（r(2)=0.392；0.20<P<0.50）。这些结果表明，资源可用性的操纵可以改变种内比较中总酚类物质和单宁类物质之间的相关性。这些措施之间观察到的相关性退化的原因（无论是定性的、定量的还是两者兼而有之）尚不清楚，需要进一步调查。
