Abstract The pollen morphology of 23 Brazilian native species of Rubiaceae Juss. from forest fragments of a Cerrado area was analyzed using light microscopy (LM) and scanning electron microscopy (SEM), in the search for new characters that might increase the knowledge on the pollen morphology of the species, and also aiming to help in the taxonomic characterization of the genera. For LM, the pollen grains were acetolyzed, measured, photographed and described qualitatively, whereas for SEM, the non-acetolyzed pollen grains were observed for further details of ornamentation. The analyzed species were grouped into three pollen types based on pollen unit and polarity, and three subtypes were separated considering the type of apertures; the surface ornamentation details were evidenced within each pollen type. The pollen grains are tetrad (Randia, microreticulate) or monad, apolar and inaperturate (Psychotria, reticulate-retipilate) or 2-porate (Coussarea, microreticulate), isopolar and porate (3-porate – Chomelia, reticulate-retipilate; Faramea, microreticulate-striate; Guettarda, reticulate-retipilate or rugulate; 3–4-porate – Tocoyena, foveolate; 6-porate – Mitracarpus, microreticulate-baculate), colpate (3-colpate – Psychotria, reticulate-retipilate; 7-colpate – Borreria, microreticulate-baculate), colporate (3-colporate – Chiococca and Ixora, microreticulate, Genipa and Simira, reticulate; Coutarea, microreticulate-echinate; Rudgea, microreticulate-baculate; 4-colporate – Manettia, reticulate). The metric data of the pollen grains examined by descriptive and multivariate analysis (Principal component analysis and Cluster analysis) allow the distinction of groups of species based on the size and shape. The results indicate the importance of qualitative and quantitative data and reinforce a wide morphological pollen diversity of Rubiaceae species from forest fragments in Cerrado which confirms the family as eurypalynous.

中文翻译：

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塞拉多森林碎片茜草科的花粉形态：花粉单位、孔径类型的极性和多样性

摘要 巴西茜草科23种本土植物的花粉形态。使用光学显微镜 (LM) 和扫描电子显微镜 (SEM) 对来自塞拉多地区森林碎片的样本进行分析，以寻找可能增加对该物种花粉形态知识的新特征，并旨在帮助分类学属的表征。对于 LM，花粉粒被乙酰化、测量、拍照和定性描述，而对于 SEM，观察未乙酰化的花粉粒以获得更多的装饰细节。根据花粉单位和极性将分析的物种分为三种花粉类型，并根据孔的类型将其分为三个亚型；每种花粉类型都证明了表面装饰细节。花粉粒是四分体（Randia，通过描述性和多变量分析（主成分分析和聚类分析）检查的花粉粒的度量数据允许基于大小和形状区分物种组。结果表明定性和定量数据的重要性，并加强了来自塞拉多森林碎片的茜草科物种广泛的形态花粉多样性，这证实了该科是广花属。