木材细胞壁超微构造的形成、表征及变化规律

细胞壁是木材的实体物质，细胞壁超微构造因纤维素大分子链复杂的排列方式而具有多样性。微纤丝和结晶区均属木材细胞壁的超微构造，其形成、表征及变化规律的研究取得了很多进展。从微纤丝和结晶区的生物形成、微纤丝角和结晶度的表征方法、微纤丝角和结晶度在木材径向及轴向上的变化规律和少数树种中微晶形态变化特点，以及细胞壁超微构造与细胞形态的相关关系进行了综述，提出微纤丝取向形成机制的研究，细胞壁各层厚度累积的过程，以及纤维素微晶形态在木材生长过程中的变化规律研究将成为新的研究热点，以期为基于细胞壁微纤丝角、结晶度和微晶形态来进行多性状的综合遗传改良和早期良种选育等提供重要的科学依据。

Formation,characterization and change of ultrastructure in wood cell wall

Cell walls are the solid substances of wood. The ultrastructure of cell wall in woods is diverse because of the complex arrangement of cellulose macromolecules. The microfibril angle and crystalline area are generalized ultrastructure of wood cell wall; the research on their formation, characterization and change have made great progresses. This paper reviewed the formation of microfibrils and crystalline area, the measurement methods of various cell wall ultrastructure and the change characteristics of microfibril angle and crystallinity in radial and axial direction, the size of crystallites in a few tree species and the relationship of wood tracheid or fiber length with microfibril angle and crystallinity. The paper also proposed future research on the formation mechanism of microfibrils orientation, the accumulative process of layers in cell wall and the characteristics of crystallite morphology in the growth period in order to provide important scientific basis for comprehensive genetic modification of multi-traits and early breeding according to the cell wall cellulose microfibril angle, the crystallinity and crystallite morphology.