For investigations of ongoing processes in plants, such as photosynthesis in conifer leaves, nondestructive and noninvasive measuring techniques are needed. In this paper, a novel approach has been developed for the measurement of chloroplasts’ numbers and pigment contents in conifer leaves based on the measurements of leaf absorption spectra using optical fibers and an array spectrophotometer. To eliminate the effect of scattering on the measured absorption spectra, a strategy has been applied taking advantage of the combined use of thin optical fibers normal to the needle's longitudinal axis and the phenomenon that scattering is largest in the forward direction. The optical path in the leaf is nearly the distance between the fiber tips; thus, we were able to obtain the absorption spectrum of the pigments in situ. A effect of the measured absorption spectra, occurring due to the organization of pigments in the leaf and interaction between light and leaf interior, can be accounted for by using the so-called Duysens transformation. Using this transformation, pigment contents and the relative number of chloroplasts can be obtained from the measured absorption spectra. We applied the method to observe pigment concentrations in different stages of the greening process in the leaves of two conifer species, Taxus baccata and Picea abies . The presented method may be used to estimate changes in chloroplast number and pigment content during various phases of greening of a species and to observe differences among various species.

中文翻译：

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使用光纤测量完整针叶树叶子的吸收、叶绿体的相对数量和色素含量


为了研究植物正在进行的过程，例如针叶树叶子的光合作用，需要非破坏性和非侵入性测量技术。在本文中，基于使用光纤和阵列分光光度计测量叶片吸收光谱，开发了一种测量针叶树叶片中叶绿体数量和色素含量的新方法。为了消除散射对测量的吸收光谱的影响，采用了一种策略，结合使用垂直于针纵轴的细光纤和向前方向散射最大的现象。叶片中的光路接近光纤尖端之间的距离；因此，我们能够原位获得颜料的吸收光谱。由于叶子中色素的组织以及光与叶子内部之间的相互作用而发生的测量吸收光谱的影响可以通过使用所谓的杜伊森斯变换来解释。利用这种变换，可以从测量的吸收光谱中获得色素含量和叶绿体的相对数量。我们应用该方法观察了两种针叶树种红豆杉和冷杉叶子在绿化过程不同阶段的色素浓度。该方法可用于估计物种绿化不同阶段叶绿体数量和色素含量的变化，并观察不同物种之间的差异。