中文摘要：

为了探讨杨树无性系木材密度、纤维形态及纤维素含量在无性系间和株内的变异模式,对7个杨树无性系胸径处按年轮取样测定了木材密度、纤维长度、纤维宽度和纤维素含量,同时对南林-95和南林-895杨这2个无性系,分别在0、5.6、9.6、13.6、17.6、19.6和21.6m处取样测定其纵向变异。研究结果表明:1)7个杨树无性系胸径处的木材基本密度、纤维素含量、纤维宽度和纤维长宽比存在显著差异;2)木材密度、纤维长度、纤维宽度和纤维素含量在不同生长年轮间也存在显著差异,且由髓心向外呈现逐渐增大的趋势;3)不同树干高度处的平均木材密度、纤维长度和纤维宽度存在显著差异。平均木材密度随树干高度的增加而增大,最小值出现在树干基部,而纤维长度和纤维宽度呈现随树干高度递增逐渐降低的趋势,其最大值均出现在树干的5.6m处;4)回归分析表明:木材密度、纤维长度、纤维宽度和纤维素含量与生长年轮及不同树干高度的关系均可用多项式方程来描述。本文的研究结果可为杨树人工林的定向培育提供理论依据。图8表2参26。

英文摘要：

The wood basic density, cellulose content and fiber form were investigated for all sample trees at breast height (1.3 m) in seven poplar clones, and at 0 (butt), 5.6, 9.6, 13.6, 17.6, 19.6 and 21.6 m for clone Nanlin-95 and Nanlin-895, respectively, for providing information on variation patterns of wood density, fiber characteristics and holocellulose content within trees and among clones. The results showed that significant variations about wood density, cellulose content, fiber diameter and the ratio of fiber length to diameter existed among poplar clones examined. Variance analysis indicated that there were significant differences in wood basic density, fiber length, fiber diameter and cellulose content among the growth rings, which had an increasing tendency along the direction from pith to bark. The significant differences also existed in wood basic density, fiber length and fiber diameter at different tree height. The mean wood basic density had a general increase trend with increasing height of trees and the lowest was found at the base, while fiber length and fiber diameter had a general decline pattern with increasing height of trees and the biggest value was observed at the height of 5.6 m. Regression analysis indicated that the relationship between examined wood properties and growth ring number (cambial age), and the relationship between examined wood properties and tree height can be described by polynomial functions.