【作者】 陈伟；

【导师】 施季森；

【作者基本信息】 南京林业大学 ， 林木遗传育种， 2006， 博士

【摘要】 光皮桦(Betula luminif era H. Winkl)，福建省优良乡土速生阔叶树种，适应性强，材质好，用途广。由于经济价值高，市场供不应求，木材被大量采伐利用，天然林资源破坏相当严重，其基因资源保护已迫在眉睫。同时，由于光皮桦树种的采种难，实生苗分化大，难以保持优良遗传特性，达到丰产要求，光皮桦树种资源的培育受到严重的制约。2003年福建省科技厅设立重点项目“速生树种西南桦、光皮桦快繁技术及应用研究”以及福建省林业厅设立了林业科技项目“光皮桦天然居群遗传变异和遗传多样性研究”，对光皮桦树种的天然林群落结构和遗传多样性以及快繁技术进行了系统的研究，旨在研究的基础上，提出光皮桦树种天然林资源分布状况，基因资源保护策略：选择优良无性繁殖材料，推广应用。课题的研究具有重要的经济和科学价值。主要研究结果如下： 1、光皮桦天然群落结构特征及物种多样性研究 对福建省光皮桦主要分布区的10个天然群落的群落结构特征，群落物种多样性进行调查研究，结果表明：光皮桦群落由各种植物所组成的森林类型多。调查的9个样地中与光皮桦混生的植物种类有46科，78属，117种之多。其中乔木层有20科41种，灌木层有21科39种，藤本植物13科20种，草本、蕨类12科20种。光皮桦天然林群落散布性强、不连续，地域中相对独立小群体是主要存在形式，共建种各异，由混生、异龄个体组成；群落树种组成混杂，乔木层种类较多，结构不明显。光皮桦天然林群落中原生性较强的多样性指数较高，如武平县梁野山自然保护区；人为干扰强的多样性指数则较低，如邵武市卫闽乡中村。较原生的森林类型中，光皮桦重要值很低，以壳豆科为基本建群种，原生性森林类型砍伐后光皮桦作为迹地更新先锋树种，具速生、适应性强的特性，在原生类型遭到破坏后的演替过程中，光皮桦取而代之，重要值增高，成为落叶阔叶林类型之一。从植被演替的动态观点分析，光皮桦环境适生性强，在不受严重破坏的情况下，可以在自然状态下进行正常演替。 2、光皮桦天然群落遗传多样性分析 对福建省光皮桦11个天然种群的RAPD和ISSR的遗传多样性和基因多样性分析结果表明：11个天然种群的多态位点百分率RAPD标记在80％-100％之间(平均98.52％)，ISSR标记为100％。Shonnon指数和Nei指数对RAPD和ISSR数据的统计结果表明，11个天然种群中沙县罗卜岩保护区种群和武平梁野山自然保护区的遗传多样性和基因多样性最高，三明岩前镇白叶坑种群最低。种群内的遗传多样性和基因多样性明显高于种群间的遗传多样性和基因多样性。按Nei方法计算光皮桦种群间的遗传相似度和遗传距离，结果表明11个光皮桦种群间的遗传相似度两种标记的平均值在0.8943-0.9923之间，种群间的遗传分化不大，遗传距离与地理位置没有显著相关性。本文所调查的天然群落主要分布在各自然保护区以及少部分边远的山区，遗传多样性和基因多样性十分丰富，其余的光皮桦天然林种群散布性强、不连续，呈零星状分布，共建种各异，由混生、异龄个体组成，光皮桦更多还原

【Abstract】 Betula luminifera H. Winkl. is one of the with fast growth broad-leaf and high-quality timber production tree species in Fujian province. The adaptability of cultivation is wide and lumbers are used popularly. Because of the high economy value, a great deal of the timber was demanded. The natural resources were broken seriously. The Germplasm resources protection is extremely urgency. Meanwhile, it was difficult to adopt the seed, and moreover there were large differentiation by seedlings. That was difficult to keep the plantation uniform to produce high quality timber. So, the resources growing of B. luminfera was restricted seriously. In last five year’s development planning, one of the research projects was initiated by the Fujian Provincial Scientific and technological Bureau. "The mass propagation technology and application to fast growth tree species—Betula alnoides Buch-Ham and Betula luminfera H. Winkl ". And another related project to cosponsored by the Fujian province forestry department was approved "Genetic variation and diversity of natural populations of B. luminifera (first term)". This thesis was based on the main results of those projects. The community characteristics, genetic diversity of natural populations of B. luminifera and the mass propagation of B. luminifera superior materials were studied. The current situation of genetic resource of B. luminifera was evaluated, and the strategies for collection, conservation and utilization of the genetic resource were suggested. And the vegetative propagation properties of selected individuals were to be examined. The main results are as follows:1. In order to understanding the structure of natural stands, the tree population, shrub and grass layer, species diversity and spatial structure of Betula luminifera H. Winkl. communities were investigated carefully. It was showed that, the community was rich in higher plant species, which was composed by 58 plant species belonging to families or genus. The Betula luminifera H. Winkl. were showed in multiple dominance populations, the species diversity indexes of shrub layer are the biggest, and the shrub layer has richer species than other layers.2. The Random Amplified Polymorphic DNA (RAPD) markers were used for estimating the genetic variation among 11 natural populations of from Fujian province. A total of higher reproducible and discernible bands were generated by listed Primers in polymorphism. There were 91.40% of genetic variance was to be found within populations by analysis of molecular variance (AMOVA). In this case, it was suggested that more attention should to be paid within populations of Betula luminifera H. Winkl... The populations on the National Forest Farm should also be taken into consideration due to their unique genetic attributes and rich in forest resources. Some populations contained more individuals were to be sampled under the programs of collection, ex situ conservation and utilization of the genetic resources of this species.3. One hundred and one plus trees of Betula luminifera H. Winkl. were selected from更多还原