Qu Tianmeng, Xie Gan, Zheng Xinyi, Chen Xinyu, Zhang Yanru, Lu Lili, Fu Zhixi
Key Laboratory of Land Resources Evaluation and Monitoring in Southwest, Sichuan Normal University, Ministry of Education, Chengdu, China.
College of Life Sciences, Sichuan Normal University, Chengdu, China.
Front Plant Sci. 2025 Apr 8;16:1558995. doi: 10.3389/fpls.2025.1558995. eCollection 2025.
Astereae, the second-largest tribe within Asteraceae, includes numerous species of economic and medicinal importance. While comprehensive systematic studies have been conducted on Astereae classification, certain controversies remain unresolved. The taxonomic boundaries between alpine and are uncertain due to their morphological similarity, and the systematic placement of remains debated. To address these issues, we applied a combination of morphological and molecular phylogenetic approaches. 21 species from 12 genera within Astereae were selected based on a morphological and molecular phylogenetic framework. Sampling, experiments, photography, and measurements were conducted using standardized methods, resulting in 12 pollen trait parameters. These parameters were then used to construct a hierarchical dendrogram of pollen morphology. A molecular phylogeny was constructed based on ITS sequences to further elucidate the systematic relationships among these species. The results revealed that pollen morphology provides valuable insights into subtribal classifications. Significant differences in pollen size and spine morphology were observed between and , with the former exhibiting larger pollen grains with long, broad, and sparsely distributed spines. Clustering results also provided the first palynological evidence for placing within Asterinae. This study underscores the importance of integrating pollen morphology and molecular evidence to refine the classification and phylogeny of Astereae.
紫菀族是菊科中第二大的族，包含许多具有经济和药用价值的物种。虽然已经对紫菀族的分类进行了全面的系统研究，但某些争议仍未解决。由于形态相似，高山[属名未给出]和[属名未给出]之间的分类界限尚不确定，[属名未给出]的系统位置也仍有争议。为了解决这些问题，我们应用了形态学和分子系统发育方法相结合的手段。基于形态学和分子系统发育框架，从紫菀族内的12个属中选取了21个物种。采用标准化方法进行采样、实验、拍照和测量，得到了12个花粉性状参数。然后利用这些参数构建了花粉形态的层次聚类图。基于ITS序列构建了分子系统发育树，以进一步阐明这些物种之间的系统关系。结果表明，花粉形态为亚族分类提供了有价值的见解。在[属名未给出]和[属名未给出]之间观察到花粉大小和刺形态的显著差异，前者花粉粒较大，刺长、宽且分布稀疏。聚类结果也为将[属名未给出]置于紫菀亚族内提供了首个孢粉学证据。本研究强调了整合花粉形态和分子证据以完善紫菀族分类和系统发育的重要性。
