In this study, the morphology and chemical composition of pollen grains of six birch species (Betula utilis Doorenbos, B. dahurica, B. maximowicziana, B. pendula, B. pubescens and B. humilis) were examined to verify which of these features allow distinguishing them in a more unambiguous way. For this purpose, scanning electron microscopy and light microscopy, as well as Fourier transform infrared (FTIR) spectroscopy and curve-fitting analysis of amide I profile, were performed. The microscopy images show that the pollen grains of B. pubescens, B. pendula and B. humilis are similar in diameter and significantly smaller than those of others species, with the largest diameter observed for B. utilis Doorenbos. However, the results obtained from FTIR spectroscopy indicate that the chemical compositions of B. pubescens and B. pendula are similar, but B. humilis is outlaying. Summarizing, it is not possible to unambiguously state, which feature or which technique is the best for differentiating between the six chosen birch species. However, the study showed that both techniques have potential for identification of birch pollen species.

中文翻译：

---

使用 FTIR 光谱鉴定桦树花粉种类

在这项研究中，检查了六种桦树（Betula utilis Doorenbos、B. dahurica、B. maximowicziana、B. pendula、B. pubescens 和 B. humilis）的花粉粒的形态和化学成分，以验证哪些特征允许以更明确的方式区分它们。为此，进行了扫描电子显微镜和光学显微镜，以及傅里叶变换红外 (FTIR) 光谱和酰胺 I 曲线的曲线拟合分析。显微镜图像显示，B. pubescens、B. pendula 和 B. humilis 的花粉粒直径相似且明显小于其他物种，其中 B. utilis Doorenbos 的直径最大。然而，从 FTIR 光谱获得的结果表明 B. pubescens 和 B. pendula 的化学成分相似，但 B. humilis 正在支出。总而言之，不可能明确说明哪种特征或哪种技术最适合区分六种选定的桦树物种。然而，该研究表明，这两种技术都具有识别桦树花粉种类的潜力。