Comparison of fiber morphological properties and chemical compositions between normal wood and tension wood in poplar clone 107 (Populus×Euramericana cv.‘Neva’) tree | 欧美杨107正常木与应拉木纤维形态和化学组成比较

Chinese. 对欧美杨107（以下简称107杨）应拉木与正常木的纤维形态及化学组成进行全面比较和分析，为杨树应拉木的合理高效利用提供依据。以直立生长和倾斜生长的107杨为研究材料，通过合理方法区分正常木和应拉木，再对应拉木的解剖构造进行电镜观察，着重比较了107杨正常木和应拉木在纤维形态及化学组成的差异。107杨应拉木具有典型的应拉木解剖构造，即细胞壁中存在明显的胶质层。正常木与应拉木纤维形态比较结果表明，应拉木的双壁厚、壁腔比、木射线比量和纤维比量均高于正常木，而正常木的纤维长度、纤维宽度、纤维长宽比、胞腔径、微纤丝角、导管比量均大于应拉木。引用单因素方差分析比较正常木与应拉木之间纤维形态的差异，结果表明，正常木与应拉木纤维宽度、胞腔径、双壁厚、壁腔比在P=0.001水平上差异显著，纤维长度和微纤丝角在P=0.01水平上差异显著，其余形态指标差异均不显著。正常木与应拉木化学组成比较结果表明，应拉木的综纤维素、纤维素、α-纤维素含量均高于正常木，而正常木的半纤维素、木质素、苯醇抽提物含量、10 g/L氢氧化钠抽提物含量均高于应拉木；单因素方差分析表明，正常木与应拉木纤维素、α-纤维素、半纤维素、木素、10 g/L氢氧化钠抽提物含量的差异在P=0.001水平上显著，其余指标差异均不显著。107杨正常木与应拉木的主要纤维形态指标和化学组成存在明显差异，在木材加工利用时需要区别对待。

English. In order to provide information for effective utilization of tension wood, both fiber morphological properties and chemical compositions of normal wood and tension wood of poplar clone 107 were determined for implementing comprehensive comparison between them. Straight and inclining poplar clone 107 tree were selected as studying materials in this study. At first, normal wood and tension wood was separated by reasonable method, and then anatomical features of tension wood were observed by SEM. Comparison of fiber morphological properties, chemical composition, and specific density between normal wood and tension wood was implemented. The results showed that tension wood of poplar clone 107 had a typical anatomical feature as tension wood, which is characterized by an apparent gelatinous layer existed at cell wall. Value of double width of cell wall, runkel ratio, ray proportion and fiber proportion was higher at tension wood than normal wood. Conversely, fiber length, fiber width, ratio of fiber length to width, diameter of lumen, MFA and vessel proportion was higher at normal wood than tension wood. One-way ANOVA was introduced to illustrate difference of fiber morphological between normal wood and tension wood. It was shown that difference of fiber width, diameter of lumen, double width of cell wall and runkel ratio was significant at P=0.001 levels, and fiber length and MFA was significant at P=0.01 levels. Other comparisons were unapparent. When it came to comparison of chemical composition and specific density between normal wood and tension wood, it was found that tension wood had higher content of holo-cellulose, cellulose,α-cellulose than normal wood. In contrast, content of semi-cellulose, lignin, benzene-alcohol extractives, 10 g/L NaOH extractives was higher at normal wood than tension wood. Similar variance analysis was used for further clarified difference between normal wood and tension wood at chemical compositions and specific density. Significant different at P=0.001 levels was found at cellulose content,α-cellulose content, semi-cellulose content, lignin content, and 10 g/L NaOH extractives content. No further significant difference was detected. Most of difference of fiber morphological properties and chemical compositions between normal wood and tension wood were significant. So, this difference should be noticed when these wood materials were under further processing and utilizing.