贵州产蜘蛛抱蛋属植物花粉扫描电镜研究

Study of pollen of Aspidistra from Guizhou by scanning electron microscopy

目的:研究贵州产蜘蛛抱蛋属植物不同种之间花粉外壁纹饰的特征差异及演化关系。方法:采用扫描电子显微镜对平塘蜘蛛抱蛋A.pingtangensis、荔波蜘蛛抱蛋A.liboensis、赤水蜘蛛抱蛋A.chishuiensis、贵州蜘蛛抱蛋A.guizhouensis、黔南蜘蛛抱蛋A.australis等14种贵州产该属植物的花粉形态进行了观察,通过对不同种花粉的极面观、赤道面观及表面纹饰进行拍照,详细描述该属植物不同种花粉的外部形态。结果:通过对花粉影像的观察发现,花粉粒均为球形或长球形,极轴长21μm^38μm,赤道轴长18μm^30μm,极轴与赤道轴比为1.04~1.36。花粉粒外壁可归纳为三大类型:皱波状纹饰,芽孢状纹饰和瘤棒状纹饰;而不同种的花粉外壁纹饰皆有自己独有的特点,说明了不同种之间在花粉特征上存在着较大差异。结论:花粉粒的外部形态特征可为贵州产该属植物的鉴别提供一个较为重要的依据,具有一定的分类学意义。14种贵州产该属植物的花粉外壁纹饰演化方式为:皱波纹修饰—芽孢状修饰—瘤棒状修饰。

In this research we studied the pollen surface structure of different species of Aspidistra from Guizhou,and tried to figure out their differences in characteristics and their connection in evolution. The pollen morphology of14 species of Aspidistra from Guizhou,including A. pingtangensis,A. liboensis,A. chishuiensis,A. guizhouensis,A. australi etc. were examined by SEM. Images of the polar view,equator view and surface pattern of the pollen of each species were taken to depict their surface structures in detail. By observing the images of the pollen,we found out that the shape of the pollen grains of the 14 species are either globular or prolate,with their polar axis length of 21μm to 38 μm,their equatorial axis length of 18 μm to 30 μm,and P/E value of 1. 04 to 1. 36. The surface patterns of the pollen could be categorized into three types： wavy wrinkle shape,spore shape,and tumor rod shape.Each species bore its own characteristics and the differences between them were great. Therefore the surface structure of pollen grains could provide a prominent clue for identifying Aspidistra plants. The evolving process of the surface structure of these 14 species of Aspidistra in Guizhou was from wavy wrinkle shape to spore shape,then to tumor rod shape.