【作者】 孙丰波；

【导师】 张志毅；

【作者基本信息】 北京林业大学 ， 林木遗传育种， 2007， 硕士

【摘要】 毛白杨是我国特有的优良乡土树种,主要分布在我国黄、淮海流域约100万km2的范围内,在我国北方,尤其是黄河中下游地区的林业生产和生态环境建设中占有重要地位。对毛白杨自然分布区内的优良无性系进行木材品质遗传变异研究,将为该树种重要材性性状的遗传改良及其分子育种奠定重要的科学理论基础,具有重要的实践意义。本文以全国毛白杨基因库中8个种源(北京、河北、山东、河南、山西、陕西、安徽、江苏)共574个无性系为试材,对毛白杨重要的木材品质性状进行了遗传变异研究。研究的主要木材品质性状包括:木材基本密度、纤维长度、纤维宽度、纤维长宽比、纤维壁腔比等5个性状。分析了这些性状在种源间和种源内无性系间的遗传变异,以及株内径向不同取样部位的变异趋势。得到如下主要研究结果:1、毛白杨无性系木材品质性状在种源间的差异均达到极显著水平。木材基本密度、纤维长度及纤维宽度等性状种源间的变化范围分别为0.4204g/cm3-0.4615g/cm3、0.75mm-1.56mm、18.46um-28.86um。对于木材基本密度这一重要性状,其种源间重复力为0.926;而对于木材纤维形态如纤维长度、纤维宽度、纤维长宽比和纤维壁腔比等性状的种源间重复力在径向不同取样部位的均值分别为0.976、0.971、0.942、0.809。研究结果初步表明,种源间毛白杨无性系木材品质性状主要受强的遗传控制。种源间毛白杨无性系木材品质性状的多重比较结果显示,所有种源间的差异在不同性状和不同取样部位中表现的变化规律不同。2、种源内毛白杨无性系间大多数木材品质性状的变异极其明显。木材基本密度最大值为0.4814g/cm3,最小值为0.4204 g/cm3,分别出现在北京种源和安徽种源;纤维长度性状最大值为1.97mm,出现在北京种源,最小值为0.44mm,出现在河北种源;纤维宽度性状最大值为38.85um,出现在北京种源的。最小值出现在河北种源,值为8.43um。研究表明,除木材基本密度在部分种源内的差异不显著外,其它性状在种源内无性系间的差异均达到极显著水平。在此基础上,对纤维形态种源内的重复力进行了分析,结果表明,纤维长度,纤维宽度、纤维长宽比及纤维壁腔比等性状在无性系间的重复力均值分别为0.946、0.949、0.935、0.905。以上分析表明,种源内毛白杨无性系间木材品质性状也受强的遗传控制。3、毛白杨无性系株内径向不同取样部位的木材品质性状间的变异呈一定的变化规律,其主要表现为:纤维长度与纤维长宽比的径向变异趋势相似,即从髓心到树皮逐渐变大,当达到最大值后趋于稳定;纤维宽度与纤维壁腔比的径向变异均在中心值附近,呈不规则的上下波动。所有种源内毛白杨无性系株内径向不同取样部位间木材品质性状的差异均达到极显著水平。8个种源内毛白杨无性系径向不同取样部位纤维长度、纤维宽度、纤维长宽比、纤维壁腔比的重复力均值分别为0.992、0.888、0.983、0.920。上述研究表明,所研究的毛白杨各木材品质重要性状在种源间、种源内以及径向不同取样部位间变异及其明显,均受强的遗传因子控制。这一研究为毛白杨木材纤维品质性状的优良无性系选择、亲本选配及分子育种提供了重要的理论依据,对毛白杨木材工业的纤维原料遗传改良具有深远的意义。更多还原

【Abstract】 Populous tomentosa Can., a native species in China, has played a key role in timber production and ecological environment construction along the Yellow River. It is mainly distributed in the vast area of northern China, and occupied about one million km~2. Study on inheritance and variation of wood property for excellent clones, collected from 8 provinces or city in China, found the base of scientific theory for improvement of important traits of wood property, and has great practical significance in Populus tomentosa.A total of 574 clones sampled from 8 provenances, i.e. Beijing, Hebei, Shandong, Henan Shanxi, Shannxi, Anhui, and Jiangsu, planted in the national gene pool of Populous tomentosa, were studyed on inheritance and variation of wood property with wood basic density, fiber length, fiber width, ratio of fiber length to width and ratio of wall to cavity. The patterns of inheritance and variation among provenances, clones and sample locations in radial direction were analyzed. The major results and conclusions are described as follows.1. Variation of wood property among provenances is of significant difference at the level (P >0.01) in Populous tomentosa. The variation range among provenances at different sample locations of fiber length, fiber width were 0.4204g/cm~3～0.4615g/cm~3,0.75mm～1.56mm and 18.46um～28.86um, respectively. As for the wood basic density, an important trait, its repeatability of among provenances was 0.926. On average, repeatability among provenances at different sample locations of fiber length, fiber width, ratio of fiber length to width and ratio of wall to cavity respectively were 0.976, 0.971, 0.942, 0.809. The results showed that the traits of wood property among provenances were mainly controlled by genetic factors. From the multiple contrast among provenances of wood property, the patterns of variation between each two provenances were strongly different in different traits and samples locations in radial direction.2. The variation of wood property in provenances was apparent in Populous tomentosa. The maximum values of wood basic density, fiber length and fiber width appeared in Beijing provenance, they respectively were 0.4814g/cm~3 , 1.97mm, 38.85um. The minimum value of wood basic density , 0.4204 g/cm~3, appeared in Anhui provenance, the other two traits, e.l., fiber length and fiber width appeared in Hebei proveance, they respectively were 0.44mm and 8.43um. Variation of the wood property in provenance were significant difference (P>0.01), except for the wood basic density. The average repeatability of fiber length, fiber width, ratio of fiber length to width and ratio of wall to cavity were 0.946, 0.949, 0.935, 0.905, respectively. The results showed above revealed that the traits of wood property in provenances were mainly controlled by genetic factors in Populous tomentosa.3. The variation of wood property in radial direction marked the patterns of changes, i.e., The patterns of variation of fiber length and ratio of fiber length to width with radial direction was similar. They are continually come up to the maximum with direction of from marrow to cortices, and then fixed. Pattern of changes of fiber width and ratio of wall to cavity were waved above and below along one center point. Variation of the wood property in different sample locations were different at the level of P>0.01. The average repeatability at different sample of fiber length, fiber width, ratio of fiber length to width and ratio of wall to cavity were 0.992, 0.888, 0.983 and 0.920, respectively.The results showed above indicated that the variation of all important traits of wood property analyzed in this study were significant difference in provenance, among provenances, and in different sample locations in radial direction, and they were mainly controlled by the genetic factors. This study provided important theoretical foundation for selection of excellent clones, parental selection of hybridization and molecular breeding for improvement of wood property. The results, therefore, will produce the important effects on genetic improvement of industrial feedstocks of fiber material in P. tomentosa.更多还原