竹材木质素在细胞壁中的微区分布

Lignin Distribution in Cell Wall of Bamboo Culms(Phyllostachys pubescens and Pseudosasa amabilis)

对12个月的毛竹和茶秆竹进行了木质素微区分布的研究,实验运用光学显微镜和激光共聚焦扫描显微镜鉴定了木质素的存在,并且利用组织化学染色方法及其可见光显微分光光度计半定量测定竹材纤维?薄壁组织和导管的细胞壁各微区木质素含量。毛竹竹茎各组织细胞壁各微区的木质素含量均大于茶秆竹相应部位的。木质素在各组织中均有分布,其含量因组织类型及其细胞壁不同微区而有差异,其结构中存在愈创木基(G)和紫丁香基(S)两种木质素组成单元。竹壁径向和纤维帽不同位置的木质素含量未有明显的规律性变化。纤维次生壁具有薄厚层交替的多层结构,薄层的木质素含量大于厚层的。

Lignin distribution in different anatomical regions of 12-month-old bamboo species,namely moso bamboo and Pseudosasa amabilis Keng f.was investigated.Lignification was studied by means of optical microscopy and confocal laser scanning microscopy.In addition,distribution of lignin in different tissues（fibre,parenchyma and vessel） was investigated by visible-light microspectrophotometry coupled with Wiesner and Mule reaction.Lignin is widely distributed in different tissues,in which there is lignin content difference among tissues and anatomical regions.Guaiacyl lignin units and syringyl lignin units can be found in cell wall of fibre,parenchyma and vessel.There is no regular variation in lignin content along different radial location of culms and different location in fibre strands.The multilayer of the fibre secondary cell wall has alternating thick and thin layers,while lignin content of thin layer is higher than that of thick layers.