[Objective] In order to reveal chemical constituents distribution rule of bamboo fiber cell wall,distribution of some important chemicals within single fiber cell was studied.[Method] Six-year-old moso bamboo (Phyllostachys edulis) was chosen and sampled into ultrathin section as research material.High-resolution confocal Raman microscopy was used to collect Raman spectrum of bamboo fiber in situ.The chemical constituents distribution of moso bamboo fiber cell wall was analyzed through Raman imaging technique.[Result] S unit and G unit of lignin widely distributed in all layers of wood cell wall,but H unit mainly distributed in layers that close to peripheral region.The distribution pattern of hydroxycinnamic acids was similar to that of H unit,i.e.mainly distributed in peripheral region of cell wall.Cellulose had a relatively even distribution in thick layers,and the concentration of cellulose was higher in thick layers than that of thin layers.Lignin concentration decreased from periphery to central part of a fiber cell,with relative higher value at compound middle lamella,lumen edge as well as interface between two layers which formed local accumulation at those regions.[Conclusion] The bamboo fiber cell wall has different chemical composition in radial direction,and cellulose,lignin and hydroxycinnamic acid have different distribution density within different cell wall layers.%[目的]研究竹纤维单细胞中重要化学组分的分布,揭示竹纤维细胞壁中化学组分的分布规律.[方法]以6年生毛竹为研究对象,取竹壁中部竹材,制成超薄切片,利用高分辨率激光共聚焦拉曼显微镜对纤维细胞进行原位光谱采集,通过光谱成像技术分析毛竹纤维单细胞中重要化学组分的分布.[结果]S型木质素和G型木质素广泛分布于细胞壁各壁层中,而H型木质素则主要分布在细胞外缘.羟基肉桂酸的分布与H型木质素类似,也主要存在于细胞外缘的壁层中.纤维素在细胞壁宽壁层中的分布相对稳定,且比窄壁层具有更高的分布密度;从细胞外围向细胞内部,木质素的分布密度总体呈下降趋势,在复合胞间层、细胞腔周围以及各壁层之间的交界处还具有相对较高的分布密度,形成局部聚集分布.[结论]竹纤维细胞壁径向方向具有不同的化学组成,纤维素、木质素以及羟基肉桂酸在不同壁层之间具有不同的分布密度.
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