中国无患子科的花粉形态及其系统学意义

利用扫描电镜对国产无患子科(狭义,Sapindaceae)23属30种1变种植物的花粉形态进行了观察。结果显示,该科花粉粒多为扁球形,部分为长球形,少数为球形或近球形,极面观多为三角形;从花粉萌发孔类型看,大多数种类具三沟孔,有的形成合沟,少数仅具三孔而无沟;从花粉外壁纹饰看,多数花粉外壁具网状或条纹状雕纹,少数花粉的外壁具刺状或颗粒状纹饰。花粉形态特征支持文冠果亚科(Xanthoceroideae)以及广义鳞花木属(Lepisanthes)概念,并支持仍将茶条木属(Delavaya)置于车桑子亚科(Dodonaeoideae)。观察发现黄梨木(Boniodendron minus)与栾树属(Koelreuteria),龙眼属(Dimocarpus)、荔枝属(Litchi)与韶子属(Nephelium)从花粉形态上表现出较近的亲缘关系。基于花粉形态特征编制了国产无患子科分属检索表。

Pollen Morphology and Its Systematic Significance in Sapindaceae from China

Using scanning electron microscopy (SEM), we observed the pollen grains of 30 species and one variety representing 23 genera of Sapindaceae in China. The shapes of the pollen grains of most species in this family were oblate or prolate, rarely spheroidal to subspheroidal in equatorial view and triangular in the polar view. The aperture types were tricolporate, rarely triporate. The pollen exine sculptures were striate or reticulatoid, rarely prickly or granulate. The Xanthoceroideae, broadly defined Lepisanthes,and placement of Delavaya in Dodonaeoideae were supported by the pollen morphology. The close relationships between Boniodendron minus and Koelreuteria,and that among Dimocarpus,Litchi and Nephelium were also supported by the pollen morphology. A key to the genera of Sapindaceae based on the pollen morphology was presented.