5种裸子植物花粉外壁成分及结构分析比较

利用傅里叶变换红外光谱仪对银杏、日本冷杉等5种裸子植物的花粉外壁成分进行测定分析,结果表明,这5种裸子植物花粉外壁的红外光谱主要由蛋白质、脂类及多糖类物质的特征吸收峰组成。但不同科属间的花粉外壁主要成分含量存在较大差异,其中银杏科的银杏花粉外壁以蛋白质含量最为丰富;松科的雪松花粉外壁以脂类物质较为丰富;杉科的日本冷杉、杉木和日本柳杉花粉外壁成分以多糖类物质为主,但种间花粉外壁成分仍存在差异。采用扫描电镜观察5种裸子植物花粉,显示银杏、柳杉和杉木花粉粒体积较小,不具气囊,银杏花粉粒外壁表面具较均一条纹状纹饰,日本柳杉和杉木花粉粒外壁具颗粒状突起。雪松和日本冷杉花粉粒具气囊,体积较大,花粉外壁分别是粗糙具小穴状纹理以及表面光滑具微穿孔。

Analysis on Composition of Pollen Exine and Pollen Morphology in Five Species of Gymnosperm

Fourier transform infrared (FTIR) spectroscopy was used to study the composition of pollen exine in five species of gymnosperm, including Ginkgo biloba L., Abies firma Sieb et Zucc., Cedrus deodara(Roxb.) G.Don, Cunninghamia lanceolata(Lamb.) Hook, and Cryptomeria japonica(L.f.) D.DON. The results showed that the infrared spectra of these pollen exines are mainly composed of the absorption bands of protein, lipids and polysaccharides, however, there were different components of pollen exine in these 5 species of gymnosperm. For example, there was much protein in pollen exine of G.biloba; rich lipids in pollen exine of Sonko; and polysaccharides in pollen exine of Taxodiaceae. In addition, there are significant differences in the spectra of different genus. Using scanning electron microscope, we observed that the pollens of C.deodara and A.firma are big in size, with two sacs. In contrast, the pollens of the other three species are small in size, without sacs. The surface of pollen exine in C.japonica and C.lanceolata showes orbicules, but that of C.deodara(Roxb.) G.Don and A.firma Sieb et Zucc shows the ornamentation of microgranulates with rough surfaceand smooth surface showing apertures.