柠条正常木与受拉木纤维细胞超微结构及木质素微区分布研究

采用透射电子显微镜（TEM）、扫描电子显微镜-X射线能谱仪（SEM-EDXA）及共聚焦激光扫描显微镜（CLSM）研究了柠条（Caragana korshinskii）正常木与受拉木纤维细胞的超微结构及木质素在细胞壁中的分布。结果表明,柠条正常木纤维细胞壁分为胞间层（ML）、初生壁（P）、次生壁外层（S1）、次生壁中层（S2）、次生壁内层（S3）;而受拉木与正常木不同,其细胞S3层被凝胶层（G层）取代。正常木与受拉木中导管和木射线细胞壁的木质素浓度均比纤维细胞壁的高。正常木纤维细胞各形态区的木质素浓度不同,细胞角隅区的木质素浓度最高,其次是复合胞间层（CML）,S2层最低。柠条受拉木纤维细胞壁中除G层未木质化外,与正常木细胞壁各层木质素分布相似。

Ultrastructure and Lignin Distribution in Fiber Cell Walls of Caragana Korshinskii Normal Wood and Tension Wood

Ultrastructure and lignin distribution in fiber cell walls of Caragana korshinskii normal wood and tension wood were studied by using TEM, SEM-EDXA and CLSM. The results showed that fiber cell wall in normal wood consists of middle lamella ( ML), the primary wall (P) , the outer (S_1 ) , the middle ( S_2 ) and the inner layers ( S_3) of secondary wall. However, the Gelatinous (G) layer is replaced the S3 layer in tension wood. Both normal wood and tension wood has higher lignin concentration in vessels and rays than in fibers. In normal wood, lignin concentration is the highest in cell corner midlle lamella ( CCML) , followed by in compound middle lamella (CML), and is the lowest in S2 layer. Lignin distribution in tension wood is similar to that in normal wood, except for the non-lignified G layer.