毛红椿天然群体遗传多样性及取样策略探讨  

Discussion on Genetic Diversity and Sampling Strategy of Natural Toona ciliata var. pubescens Populations

作　　者：刘军[1] 乔卫阳 邱勇斌 刘学松[3] 陈日红[3] 钟志真 余峰 姜景民[1] LIU Jun;QIAO Wei-yang;QIU Yong-bin;LIU Xue-song;CHEN Ri-hong;ZHONG Zhi-zhen;YU Feng;JIANG Jing-min(Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, Zhejiang, China;Kaihua County Forest Farm, Zhejiang Province, Kaihua 234300, Zhejiang, China;Forest Bureau of Jiande City, Zhejiang Province, Jiande 311600, Zhejiang, China)

机构地区：[1]中国林业科学研究院亚热带林业研究所,浙江杭州311400 [2]浙江省开化县林场,浙江开化234300 [3]浙江省建德市林业局,浙江建德311600

出　　处：《林业科学研究》2019年第1期175-184,共10页Forest Research

基　　金：国家自然科学基金项目(31570658);浙江省农业(林木)新品种选育重大科技专项(2016C02056-3)

摘　　要：[目的]研究毛红椿天然群体遗传多样性取样策略,为其种质资源收集、保存和遗传多样性保护等提供参考依据。[方法]利用8对微卫星分子标记进行毛红椿天然群体遗传多样性和空间自相关分析,综合制定其天然群体合理取样策略。[结果]毛红椿天然群体等位基因数平均为7.5个,期望杂合度(H_e)和多态性信息指数(PIC)均值分别为0.643 7和0.636 0,基因分化系数(G_(ST))均值为0.290 7。在遗传多样性取样策略方面,提出了根据毛红椿群体基因分化系数来确定取样群体遗传变异所占总变异比例的运算公式为1-(G_(ST))^(n-1),其中,n为取样群体的数量。当取样群体达到4个时,基本上能包括该树种97.5%的遗传变异;同时确定了目标群体的选择方法,应选择与其它群体间基因分化系数均值较大的4个群体,即贵州册亨(CH)、浙江遂昌(SC)、浙江仙居(XJ)和云南师宗(SZ)。通过构建云南宾川(BC)、云南师宗(SZ)和江西宜丰(YF)群体内取样单株数量与基因多样性和等位基因之间的捕获曲线,确定了群体内取样单株数量应达到15个以上;毛红椿天然群体内300～520 m范围内的单株间存在相似关系,超出此范围个体间差别较大,说明在进行群体内单株取样时,单株间距应大于520 m。[结论]取样群体数量、群体间遗传分化系数、群体内单株数量以及单株间距离等影响了毛红椿取样群体的遗传多样性。毛红椿天然群体遗传多样性取样策略为取样群体4个、每个群体最少取样15个单株,单株间距大于520 m。[Objective] To study the genetic diversity and sampling strategy of natural Toona ciliata var. pubescens populations and provide references for protecting their genetic diversity as well as collecting and preserving germplasm resources.[Method] Nine natural populations of T. ciliata var. pubescens were collected in its distribution zone. The population genetic diversity, spatial autocorrelation analysis were conducted with 8 microsatellite markers. Simulated sampling methods were used to develop sampling strategy of natural T. ciliata var. pubescens populations.[Result] The results showed that the average number of alleles were 7.5. The mean expected heterozygosity and polymorphism information index ( PIC ) was 0.643 7 and 0.636 0, respectively. The average coefficient of genetic differentiation ( G ST ) among populations was 0.290 7. For genetic diversity sampling strategy of T. ciliata var. pubescens , a formula for determining the proportion of genetic diversity was found using G ST and number of populations: 1-(GST )^ n-1 , where n means the number of populations. Therefore, when four natural populations, which from Ceheng of Guizhou Province, Suichang of Zhejiang Province, Xianju of Zhejiang Province, and Shizong of Yunnan Province, were selected for conservation and sampling, 97.5% of genetic variation was captured. The population with higher average coefficient of G ST among other populations was chosen. The mean allele number and genetic diversity increased with the increase of sampling individual in Shizong population from Yunnan Province, Binchuan population from Yunnan Province, and Yifeng population from Jiangxi Province by using captured curve. When sampling individual in a population reached 15, total alleles and 99.5% genetic diversity were captured. So more than 15 individuals should be sampled when germplasm of T. ciliata var. pubescens were conserved and sampled. Similarity relation existed among individuals within a distance of 300-520 m. There were great differences among individuals over this

关 键 词：种质资源 保护遗传学 香椿属 遗传变异 基因分化系数 

分 类 号：S718.46[农业科学—林学]