A STUDY ON ULTRASTRUCTURE OF COTTON FIBER
棉纤维超微结构的研究

Ultrastructure of cotton fiber was studied by X-ray diffraction technique. The results were:Crystallite size in fiber axis direction and direction of normal to fiber axis are 12.7nm and 6.6nm respectively,Distortion in these direction are 0.69% and 3.28% respectively.The mean microfibrillar spiral angle of S2 secondary cell walls of cotton fiber during development declined with days of post-anthesis,and orientational degree of cellulose crystallites increased with days of post-anthesis. Crystallinity increased slowly and steeply which did in 5-14 days and 14-17 days respectively. Later it increased very slowly and became stable.The microfibril spiral angle increased in the upper level fruit branches and the outer fruit nodes. The relative orientational index decreased slowly as the ordinal number of fruit branches increased from below,and decreased slowly as the ordinal number of fruit nodes increased from inside. This research demonstrated that qualitative characters were significant correlaed with orientational parameters of cotton fiber and relationship between them was developed. Qualitative characters of cotton fiber depended mainly on the orientation parameters.