毛白杨枝条木质部细胞分化的动态变化及其与形成层活动的相互关系

Dynamic Changes in Cambial Anatomy and Xylem Cell Differentiation of Shoots in Populus tomentosa

应用定量解剖学和显微图像分析技术 ,得到了毛白杨枝条形成层细胞与其衍生木质部细胞解剖特征在形成层活动期内的变化情况 ,并探讨了两者之间的关系。采用X射线微密度测定技术 ,了解了同一生长轮内木材密度沿径向方向上的变异 ,讨论了其与木质部细胞解剖特征之间的关系。结果表明 ,形成层纺锤形细胞的径向和弦向宽度在活动期不同阶段差异不显著 ,而纤维长度、纤维宽度、壁腔比、微纤丝角、导管分布频率和胞壁率差异极显著 ;导管组织比量差异显著 ;导管分子长度、纤维比量和射线比量差异不显著。同一生长轮内木材密度的径向变异与活动期不同阶段形成的木质部细胞数量及其解剖特征直接相关。形成层带细胞层数与纤维长度、纤维长宽比和壁腔比呈极显著负相关 ,与纤维宽度呈显著正相关 ;形成层纺锤形细胞的径向宽度与纤维长度、纤维长宽比和射线比量呈显著负相关 ;形成层纺锤形细胞的弦向宽度与纤维宽度呈显著正相关。总体看来 ,在整个形成层活动期 ,形成层纺锤形细胞与木纤维的解剖特征之间随时间变化的相关性较好 。

Some approaches of quantitative anatomy, micrological image analysis and X ray microdensitometry were used to explore the anatomical properties of cambial cells and different xylem cells at different phases in this paper, and the histological relationships between cambial cells and xylem cells were discussed. The dynamic changes were determined in the anatomical properties of cambial cells and xylem cells during cambial active phase. No significant differences in tangential and radial width of cambial fusiform cell, length of vessel element, ratio of fiber and ray tissue were found among different stages. However, there existed significant differences in fiber length and width, ratio of fiber wall to lumen, microfibril angle, cell wall percentage, ratio of vessel tissue and distributing frequency of vessel. The radial variation of wood density within annual ring had a close relationship to that of the productivity and anatomical properties of xylem cells at different stages. Correlation analysis indicated that cambial cell number had strong negative correlations with fiber length, ratio of fiber length to width and ratio of fiber wall to lumen, and a positive correlation with fiber width. Meanwhile, the radial width of cambial fusiform cell had negative correlations with fiber length, ratio of fiber length to width and ratio of ray tissue, and a positive correlation existed between tangential width of cambial fusiform cell and fiber width. In conclusion, the histological correlations between cambial fusiform cell and wood fiber were stronger than cambial fusiform cell and vessel element.