【作者】 瞿超；

【导师】 李悦； 殷亚方；

【作者基本信息】 北京林业大学 ， 林木遗传育种， 2005， 硕士

【摘要】 本文以尾巨桉、尾叶桉、粗皮桉为研究对象,利用应变片法测量了三个桉树树种不同无性系和家系的生长应变。在生长应变测试的基础上,分别从上述树种中选取生长应变值高于900×10^-6和低于400×10^-6的样木制作显微切片,利用可见光显微分光光度计结合M（a|¨）ule和Wiesner反应研究分化的木质部木纤维细胞和导管分子中木质素含量变化同生长应变的关系,以及成熟区域木纤维细胞和导管分子中各个形态区域木质素含量同生长应变间的关系,以便确定桉树生长应力形成的主导因子,主要研究结果如下: 1.1)尾巨桉（Eucalyptus urophylla×E.grandis）,尾叶桉（E.urophylla）,粗皮桉（E.pellif）三种不同树种间,在0.05水平下,活立木生长应变平均值差异显著。2)尾叶桉具有最低的生长应变水平。3)三种桉树活立木胸高处表面轴向生长应变多分布在450×10^-6～600×10^-6之间。 2.所测树种木质部木纤维细胞和导管分子经M（a|¨）ule反应后的可见光特征吸收峰在510nm处,经Wiesner反应后,特征吸收峰在515nm处。 3.M（a|¨）ule反应后:生长应力低的树种,分化的木质部木纤维细胞随着细胞朝着成熟细胞的发展,表现出紫丁香基木质素变化趋势较平缓;而生长应力高的树种则相对于应力低的树种,表现出更急剧变化的特点,且处于相同分化阶段的细胞数目相对较少。Wiesner反应后:表现出同M（a|¨）ule反应一致的变化。 4.在尾巨桉ECl、3327、粗皮桉和尾叶桉U6中,其木纤维细胞和导管分子在S₁分化阶段就开始沉积紫丁香基和愈疮木基木质素。低生长应力树种木纤维细胞中,其紫丁香基和愈疮木基木质素沉积量均大于高生长应力树种。在导管分子中,也有相似的结论,但是高生长应力树种在细胞分化阶段导管分子的形成似乎受到抑制,直至S₃分化阶段才出现。 5.在尾巨桉ECl成熟木纤维细胞的各个形态区域,紫丁香基和愈疮木基木质素含量都基本上为角隅处大于胞间层,胞间层大于S₂层;在导管分子中,紫丁香基和愈疮木基木质素在三个壁层含量基本相同,而在高生长应力尾巨桉ECl成熟细胞S₂层中,紫丁香基含量较S₁层要少,和S₃层相当,而愈疮木基木质素较其它两个壁层要多,其余所测树种也表现出相似的规律。更多还原

【Abstract】 The mainly materials used in this study are Eucalyptus urophylla × E. grandis, E. urophylla and E. pellit. Their growth strain was measured by strain gauge. The growth strain value of samples which were made into microsection were higher than 900 and less than 400 respectively. Then the change of lignin content in differentiating fibre and vessel as well as different morphologic region in matured fibre and vessel was observed by light microspectrophotometer couped with Maule and Wiesner reaction. According to result, the relations between the change of lignin content and growth strain are as following:A comprehensive research was conducted on eucalyptus trees from three plantation species, including E. urophylla × E. grandis, E. urophylla and E. pellita, grown in south of China. Growth strain was measured on standing trees. The analysis results in this paper showed that: 1) There were highly significant differences in the mean surface longitudinal growth strain （SLGS） of standing trees among different species. 2) E. urophylla had the lowest growth strain level in all three species tested. 3) The mean SLGS of standing trees distributes between 450 × 10^-6600 × 10^-6 mainly at 1.3m height.The results of lignin research by light microspectrophotometer couped with Maule and Wiesner reaction are as following: 1) The special absorbance values are 510nm and 515nm in fibre cell and vessel after Maule reaction and Wiesner reaction, respectively. 2) After Maule reaction, the change trend of Syringlpropane lignin content is more tempered in the species of low growth strain than high growth strain as development of differentiating fibre cell forward mature cell. After Wiesner reaction, the change trend of guaiacylpropane lignin content has the similar trend as Maule reaction. Moreover, the cell numbers in the specials of high growth strain are relatively less than low growth strain when in the same differentiated stage. 3) Syringlpropane lignin and Guaiacylpropane lignin appeared in the differentiated stage of S₁ in fibre cell and vessel of Eucalyptus urophylla × E. grandis, E. urophylla and E. pellit. In fibre cell, the species of low growth strain haslower Syringlpropane lignin and Guaiacylpropane lignin content than the species of high growth strain, hi vessel, it has the similar result as in fibre cell.But the development of vessel was restrained in Si and S2 differentiated stage in Eucalyptus urophylla x E.grandis and E. urophylla of high growth strain. 4) Different morphologic region in matured fibre and vessel have different Syringlpropane lignin and Guaiacylpropane lignin content in three species. In fibre cell, Cell corner has the most lignin content, then middle lamella, S2 layer has the least lignin content.In vessel, Si layer, S2 layer and S3 layer almost have the same Syringlpropane lignin and Guaiacylpropane lignin content. But in S2 layer of differentiating cell, Syringlpropane lignin content is less than Si layer, which have the almost same content as S3 layer. Guaiacylpropane lignin content in S2 layer is higher than the other two layer.更多还原