12种十字花科植物花粉形态研究

摘要

采用扫描电子显微镜对十字花科8属12种植物的花粉形态特征进行了观察分析.其中8种为首次报道.观察结果表明:4族8属12种十字花科植物花粉形态的一般特征为:花粉粒长球形至超长球形;极面观三裂圆形,少数四裂圆形;外壁纹饰为网状或细网状纹饰;三沟,偶四沟.12种植物的花粉可划分为5种类型:(1)花粉粒长球形,网状纹饰,三沟;(2)花粉粒超长球形,网状纹饰,三沟;(3)花粉粒长球形,细网状纹饰,三沟;(4)花粉粒超长球形,细网状纹饰,三沟;(5)花粉粒长球形,三或四沟,网状纹饰.十字花科花粉形态特征在不同族间、不同属间以及同属不同种间均没有明显规律,在十字花科分类过程中,不宜单独以花粉形态特征作为依据.%Pollen morphology of 12 species belonging to 8 genera of Brassicaceae were observed by using scanning electron microscope (SEM),among which 8 species were reported for the first time.The pollen morphology of 12 species belonging to 8 genera is very similar,their shape varies from prolate to perprolate with reticulate or reticulate-fine sculpture.The pollen grains are most tricolpate(rarely teracolpate).Five pollen types can be distinguished based on the shape of pollen grains,the size of the areole and the number of the aperture: (1)Pollen grains three-colpate, prolate, with reticulate sculpture; (2)Pollen grains three colpate,perprolate, with reticulate sculpture; (3)Pollen grains three-colpate, prolate, with reticulate-fine sculpture; (4) Pollen grains three-colpate, perprolate, with reticulate-fine sculpture; (5) Pollen grains threecolpate or four-colpate,prolate,with reticulate sculpture.There is not distinct rule about grains morphology on the level of tribe,genus and species.It is not suitable for identification in Brassicaceae only by morphological characteristics of pollen.