【作者】 韩照祥；

【导师】 张文辉； 山仑；

【作者基本信息】 西北农林科技大学 ， 植物学， 2004， 博士

【摘要】 本文以陕西境内处于分布区不同位置（秦岭北坡半干旱核心区、巴山湿润核心区和黄土高原分布边缘区）的栓皮栎种群为研究对象，通过野外实地考察、调查计测和室内实验相结合，运用种群统计学和分子生态学等的原理和方法，从生境因子、表型变异与分子动态等方面沿生境梯度系统地研究了栓皮栎种群的径级结构、种群增长、种群构型的区域变异性、种群性状分化与地理变异性以及种群的遗传多样性规律，将生态对策和生态分化有机联系起来探讨栓皮栎种群的适应性变异和进化策略，结果表明：栓皮栎种群的径级随着生境梯度的变化，径级结构也呈现出一定的区域变异性。种群补充更新能力主要靠根和伐桩的萌生苗，萌生苗更新量的变化，有助于种群通过“瓶颈效应”，保证栓皮栎有较充分的幼苗后续资源。种群的年龄和种群密度是影响栓皮栎蓄积量的主导因子，种群结构参数与生境因子的最优组合可以使栓皮栎种群蓄积量最大。栓皮栎的冠形体积、叶面积指数、总分枝率、逐步分枝率、分形维数对树冠特性的影响较大，而冠层厚度对树冠特性的影响呈现出负相关。秦岭北坡的栓皮栎种群中，种群综合性生长指标对树高的影响最大。在黄龙山区的栓皮栎种群中，树冠特性指标对胸径和栓皮厚度的影响较大，在其它两个地区树冠特性对树高和胸径的影响相差不大。不同地区栓皮栎种群的分枝分形维数、分枝角度、叶倾角存在较大的差异。从栓皮栎分布中心到分布边缘，其侧枝分枝分形维数、分枝角度和叶倾角都呈现出逐渐增大的趋势。不同地区栓皮栎的逐步分枝率和总体分枝率也是不同的，同一植株的不同层次，分枝率也呈现出层次性差异。栓皮栎种群冠型体积辅助参数的变异表明在不同的生境条件下，栓皮栎种群营养分配的不均衡性。在密度大的地区，将营养优先配送到树高生长的构件上，在密度小的地区，将营养首先分配到冠层的横向扩展上。不同生境的栓皮栎种群性状参数分化差异明显。栓皮栎种群的叶脉对数、叶柄长、叶长、叶宽和叶长宽比随着生境条件的差异而产生较大的地理变异。栓皮栎种群的叶柄长、叶长、栓皮厚度、种长和种宽随纬度的变化模式以二次抛物线方程描述最为合适；栓皮栎种群的叶柄长、叶长和栓皮厚度随海拔高度呈现明显的二次抛物线关系；而叶宽和种宽随海拔高度的变化呈现出明显的正线性相关；种长与海拔的关系为一种典型的负线性相关。多维分析认为：栓皮栎种群的同一性状的叶柄长和叶宽的相关性最强，叶长和叶宽对栓皮厚度的影响最大，叶柄长对栓皮厚度的影响最小；不同性状的叶长、种宽与栓皮厚度的相关性最强，种长对栓皮厚度的影响较小。从栓皮栎种群的分布中心到分布边缘，MDH‐1a、MDH‐1b、MDH‐2b、MDH‐2c、PGI<WP=6>２ 陕西地区栓皮栎种群区域变异性与遗传多样性的研究‐1 b、PGI‐2 b、 ADH‐1a 、ADH‐1b、ADH‐2b 的等位基因频率呈现出逐渐递减趋势；而 PGI‐1a、PGI‐2a、ADH‐2a 的等位基因频率呈现出逐渐递增趋势。说明生境条件的不同引起等位基因频率的高低之分，改变了栓皮栎种群在分布区的遗传结构。 栓皮栎种群的等位基因百分数 P、实际杂合度 H0和预期杂合度 He均高于远交风媒木本植物和其它木本被子植物，而平均每个位点的等位基因数 A 和平均每个位点的等位基因的有效数 Ae则均低于远交风媒木本植物和其它木本被子植物。 栓皮栎种群总的遗传多样性为 0.2868，种群内的遗传多样性为 0.2057，约占总遗传多样性的 78.7%，种群间的遗传变异为 0.0600，约占总数的 21.3％，种群遗传分化系数为 0.2279，群体间遗传分化为 22.79%，种群间遗传分化程度较低，在总的遗传多样性中，有 78.7%来自种群内，种群间的遗传变异为 21.3％。表明栓皮栎种群的遗传多样性主要来源于种群内不同个体间的遗传变异，而非种群间的遗传变异。从分布中心到分布边缘，栓皮栎种群内平均基因多样性表现出较大的差异。具体表现在：秦岭北坡>秦岭南坡>巴山北坡>黄龙山区，表现出栓皮栎种群内遗传多样性分布格局的不均匀性。 对栓皮栎种群内的遗传多样性与生态因子进行相关性分析认为：坡度、年平均气温、光照时间和 pH 值等生态因子与遗传多样性的相关性不显著（P>0.05），而平均土壤厚度和年降雨量生态因子与遗传多样性的相关性系数分别为 0.8764 和 0.8957，相关性较为显著（P*<0.05）；总氮和有机质的含量与遗传多样性的相关性呈现出显著的负相关性（P*<0.05）。土壤越厚，年降雨量越大，栓皮栎种群的遗传多样性越丰富。表明氮、有机质、平均土壤厚度和年降雨量在调节栓皮栎种群遗传多样性方面起着较为重要的作用。 对栓皮栎种群遗传结构的空间自相关性分析可知：栓皮栎种群内大多数等位基因不存在显著的空间自相关关系，等位基因的分布与邻近植株的基因型相关性较弱。说明栓皮栎种群的多数位点缺乏空间结构模式，其遗传变异呈现出随机分布的空间格局，与种群间地理分布的相关性不大。更多还原

【Abstract】 Quercus variabilis population of semiaridity core of north slope of Qinling ,humidity core of Bashan and Huanglong coteau was taken as the object of our studyin Shaanxi region, through field investigation 、 field determination andexperiments in the laboratory, the principles and methods were applied to studysystematically the regularity of diameter structure、increment、architecturevariability 、character differentiation and geographic variability as well asgenetic diversity of Quercus variabilis population along with habitat grads fromhabitat factors、exterior variance and molecular dynamic in Shaanxi region, suchas population ecology and molecular ecology, and also explore the adaptivevariability and evolution of Quercus variabilis population, the results are asfollows: Diameter structure takes on a certain area variability along with habitatgrads. As a whole, seedling number is lacking in four regions, population renewalmainly relys on stump-sprouting sampling, and the number of stump-sproutingsampling can help population get over “bottleneck”，and ensure adequatelycontinual resources. Population age and density are the dominant factors in influencing onpopulation accumulation volume. Meanwhile, The optimal combination ofpopulation structure parameters and habitat factors can arrive at the most foraccumulation volume Crown volume、LAI、total ramification ratio、gradual ramification ratio、branch dimension influence on tree high is the most in NSQ; Influence of crowncharacters on BD and bark thickness is the most in HLC. Ramification angle and leaf obliquity take on increscent trend along withhabitat grads, Gradual ramification ratio R1:2、R2:3 and total ramification ratioRb、secondary parameters of crown volume are different in different habitats. In general, nervation 、footstalk length、leaf length、leaf breadth、seedthickness、seed length、seed diameter and rear hair are different along withhabitats. Variance models of footstalk length、leaf length、bark thickness isparabola equation along with altitudes, variance models of leaf breadth、seedbreadth are obviously linear equation, variance model of seed length is typicallynegative correlation.<WP=8>4 陕西地区栓皮栎种群区域变异性与遗传多样性的研究 Allele frequency of MDH‐1a、MDH‐1b、MDH‐2b、MDH‐2c、PGI‐1 b、PGI‐2 b、 ADH‐1a 、ADH‐1b、ADH‐2b show minish trend, allele frequency of PGI‐1a、PGI‐2a、ADH‐2a take on increscent trend from distribution center to margin,indicate: habitat bring about allele frequent change, it influences on geneticstructure of Quercus variabilis population in distribution regions, postingadaptive significance of enzyme allele as well as correlation of allele frequencyand environments. Percentage of loci polymorphism P、observed heterozygosity H0、expectedheterozygosity He value of Quercus variabilis population is higher than that oflong distance mutual wind medium angiosperm. Average genetic diversity is different in different region, distributionpattern of genetic diversity is asymmetrical within population. Correlation of grade、average temperature、light time as well as pH valueand genetic diversity is not significant(P>0.05) by correlation analysis, andthat correlation of genetic diversity and soil thickness as well as rainfallis significant( P*<0.05), correlation of genetic diversity and nitrogen、organicmatter is remarkably negative correlation(P*<0.05), the more soil thickness, themore rainfall, the more genetic diversity, the result reveals that nitrogen、organic matters、soil thickness and rainfall play an important role in regulatinggenetic diversity of population of Quercus variabilis. Most alleles in population of Quercus variabilis markedly inexistenceautocorrelation, distribution of allele and genotype correlation of adjacentstand is weak though spatial-autocorrelation analysis, detailed analysis showedthat most allele loci lack of spatial structure pattern更多还原