【作者】 孙晓梅；

【导师】 张守攻；

【作者基本信息】 中国林业科学研究院 ， 森林培育， 2003， 博士

【摘要】 日本落叶松Larlx kaempferi)是我国主要针叶纸浆用材树种。建立在优良家系选择基础上的直接无性扩繁利用，以及优良家系选择基础上的控制授粉及杂种优势利用，是提高我国落叶松纸浆用材良种化和集约化培育的有效途径。本文以湖北省建始县15年生日本落叶松自由授粉家系子代测定林为对象，以纸浆材培育为目标，全面、系统地研究了日本落叶松家系生长、干形和材质性状的遗传变异规律，首次从数量遗传理论和生物数学两个方面探索了日本落叶松家系生长变异及遗传增益的预测，在常规育种逻辑方法应用方面，注重育种的效率和效益；建立了家系树高生长模型，分析了遗传参数随时间变化的动态趋势，并借助多性状选择指数首次为南方亚热带落叶松新引种区筛选出一批生长、干形和材质兼优的纸浆专用材家系和个体。得出的主要结论如下：性状的遗传变异 方差分析结果表明，各年龄家系间胸径、树高和单株材积存在着极显著变异，家系内个体间也存在着丰富的变异，家系间主枝长、皮厚、综纤维素含量的变异达极显著水平，主枝粗、冠幅、新枝粗、新发枝数、基本密度、早材和晚材纤维长度、早材和晚材壁腔比差异显著，1％NaOH抽出物差异达10％显著水平，由此说明这些性状具有很大的家系选择潜力，是日本落叶松选择的主体。圆满度、新枝长、分枝角和活枝下高4个性状家系间差异不显著，开展家系选择的意义不大。 日本落叶松生长、材质性状及大部分的干形性状受中等或较强的遗传控制，家系遗传力一般在O．5以上，圆满度、分枝角和活枝下高的遗传力较低，只有0．29。 日本落叶松胸径、树高等生长性状早一晚相关紧密，且主要受遗传因素制约，胸径和树高的最适早期选择年龄为6年，胸径作为早期选择指标较树高更能准确地表达成熟龄时的信息。<WP=5>性状间的相关关系 性状间表型和遗传相关分析表明，日本落叶松家系不同性状间存在着不同程度的相关关系，且利弊共存，在开展性状的间接选择时应根据选育目标进行取舍，以达到综合性状最优的目的。通过合理选择及经营，选育出生长速度快、木材密度大、综纤维素含量高、木纤维长，而1％NaOH抽出物、晚材壁腔比都较低的纸浆材新品系是完全可能的。通过对与材积性状紧密相关的胸径等9个性状的通径分析发现，胸径和树高两个性状对单木材积的直接作用占材积总变异的63％，其余性状的直接控制作用很小；冠幅、壁腔比等性状通过胸径对单木材积具有很大的间接遗传控制作用，这种控制是通过与胸径、树高的遗传相关实现的。该控制系统可说明单木材积变异的98．66％。纸浆材优良家系选择和育种程序 由胸径、树高、基本密度、纤维长度和综纤维素含量5个性状构成的等权重约束选择指数方程I=0.2751Xl+0.5215X₂-4.2408X₅+1.7437X₆+10．9114X7及以生长为主的约束指数方程I=2.6420X1+3.7782X2-42.9166X5+14.1762X6-15.8136X-7的指数遗传进展最高，且各性状的期望遗传进展也比较合理。 日本落叶松纸浆材家系育种程序应以生长性状的改良为主，兼顾干形和材质性状的改良。枝粗和皮厚是两个非常重要的形质指标。材质性状中，需保证基本密度和综纤维素含量达到一定水平，同时使1％NaOH抽出物降至较低的水平，对于落叶松幼龄材不需把壁腔比和纤维长度作为重要的材性指标加以特别考虑。家系生长模型 同一立地的不同日本落叶松家系的树高一年龄曲线为多形曲线，模型的渐近参数和速率参数不同，形状参数相同，说明不同家系的树高生长规律不同，树木的优势高生长是环境差异和遗传变异的树木表现型的综合反映，<WP=6>树高的生长潜力（立地指数）随着遗传改良材料的应用而增大。 SchumacheT和Richards模型对日本落叶松幼龄阶段家系优势高生长过程的模拟均能达到令人满意的效果。如果模型选择和计算得当，通过对子代测定林资料模拟能够得到合理的家系树高一年龄曲线，再结合已建立的落叶松一般林分的生长模型系统完全能够实现改良林分生长收获和遗传增益的预测。更多还原

【Abstract】 Larix kaempferi(Japanese larch)is one ofthe most important coniferous speciesfor pulpwood in China．Direct application of clonal propagation and hybridutilization of controlled pollination based on selected superior families isessential for improved breeding and intensive silviculture of thepulpwood-oriented Larix kaempferi．This study Was carried out in a 15一year-oldprogeny test of open-pollinated families in Jianshi County,Hubei Province．With pulpwood as a cultivated target，the genetic variation of its growth traits，stem-form and pulpwood qualities of families was comprehensively and systematically studied，and the growth variations and prediction of genetic gains of these families were explored as the first time from both quantitative genetics and biological mathematics．Height-age models for each family were established，and the age trends in genetic parameters for growth traits were analysed．Furthermore，according to its growth trait，stem-form and pulpwood qualities，a number of superior families and plus trees were selected in the subtropical region of China．Main conclusions from the study were as follows：Genetic variations among growth，stem-form and wood traitsVariance analysis revealed that DBH，height and individual tree volume weresignificantly differed from 5 yr to 15 yr among Larix kaempferi families，and SOwere among individuals within a family,which mean that there was big potential<WP=8> either for individual selection or families selection and they were the maj or sources for its genetic improvement．Among families，there were very significant differences in the main-branch length，bark thic;ss，andholo-celouse；there were significant differences in the main-branch diameter,crown width，fresh-branch diameter,fresh．branch number,wood basic densitNfiber length of early and late wood，wall／lumina of early and late wood；andthere were significant differences in the 1％NaOH extract at 1 0％level as well．This showed that these traits had great potential for family selection，and thenshould be mainly considered when conducting such selection．However,therewere insignificant differences among families in the taper,flesh．branch length，branch angle and under-branch height，which mean that family selection fromthese traits were not necessary．Heritabilities and genetic correlations for growth，wood qualities and stem．formwere estimated for open-pollinated families of Larix kaempferi．Most traits，whose family heritabilities were over 0．5，were moderately or stronglycontrolled by genetics，while those for taper，branch angle and under branchheight were low,only with 0．29．The age-age phenotypic and geneticcorrelations for DBHs，heights and volumes were very high，indicating thatthese relationships were mainly controlled by genetic factors．Six years was themost proper age for early selection in the half-sib families，and DBH was abetter indicator than height due to its genetic stability．Phenotypic and genetic correlation among traitsThe phenotypic and genetic correlation among traits of Larix kaempferi familiesindicated that the relationships among traits were complicated，i．e．，positive andnegative correlations coexisted．It was important to take a comprehensiveselection SO as to optimise all the traits according to the breeding target．It wasquite possible to pick out the right families with better performance in fast<WP=9>growth，high wood density,holo celouse，and long fiber,and low 1％NaOHextract and wall／lumina through rational selection and silvicultural measures．Path analysis of nine traits，which were highly correlated with tree volume，showed that the direct contribution of DBH and height on the variations of treevolume took up about 63％of the total variations．On the other hand，those traits，such as tree crown and wall／lumina，affected the volume strongly by indirectway of the geneti更多还原