Pollen analysis of representatives of the tribes Ampelopsideae, Cayratieae and Parthenocisseae and evolutionary history of Vitaceae genera

The family Vitaceae has a wide distribution, occurring in temperate, subtropical, and tropical climates. Vine members of the family thrive in different types of vegetation. Currently, the family includes five recognized tribes: Ampelopsideae, Cisseae, Cayratieae, Parthenocisseae, and Viteae. This study describes the pollen morphology of representatives of Ampelopsideae, Cayratieae, and Parthenocisseae. The other tribes are not described because they have been the subject of previous studies. The aim was to assess the relationships among the five tribes using multivariate analysis and to reconstruct the evolution of pollen characters using existing phylogenetic hypotheses. Specimens representing the three tribes were obtained from herbaria, treated by the acetolysis method, measured, photographed, and described using light and scanning electron microscopy. Results showed that pollen grains are medium (25–50 µm) in size, isopolar, tricolporate, and subprolate to prolate. Ornamentation varies between species. Multivariate analysis was based on quantitative characters, of which pollen diameters, apocolpium side, and polar area index were the most significant. Tracing of pollen characters showed that size, shape, and ornamentation are an evolutionary trend within the family. This investigation expands the palynological knowledge on representatives of Vitaceae tribes, contributing to future palynotaxonomic and evolutionary studies.葡萄科（Vitaceae）分布范围广泛，涵盖温带、亚热带及热带气候区域。该科的藤本类群可在多种植被类型中茁壮生长。目前学界公认该科包含5个正式认定的族：蛇葡萄族（Ampelopsideae）、白粉藤族（Cisseae）、乌蔹莓族（Cayratieae）、地锦族（Parthenocisseae）以及葡萄族（Viteae）。本研究针对蛇葡萄族（Ampelopsideae）、乌蔹莓族（Cayratieae）与地锦族（Parthenocisseae）的代表类群的花粉形态展开了描述。其余两个族因已有既往研究涉及，故未纳入本次研究范畴。本研究的目标为通过多元分析评估该科5个族之间的亲缘关系，并依托现有系统发育假说重建花粉性状的演化路径。本次研究所用的三个族的标本均取自标本馆，经醋酸分解法处理后完成测量、拍照，并分别利用光学显微镜与扫描电子显微镜进行形态描述。研究结果显示：花粉粒大小属于中型（25–50 µm），为等极结构，具三孔沟，形状呈近长球形至长球形。不同物种间的花粉纹饰存在差异。本次多元分析以定量性状为基础，其中花粉直径、极面区边长及极区指数为最具显著性的指标。花粉性状的演化追踪结果表明，花粉大小、形状及纹饰在该科内呈现出明确的演化趋势。本研究拓展了葡萄科（Vitaceae）各族类群的孢粉学认知，可为后续的孢粉分类学与演化研究提供重要参考。