摘要
利用随机扩增多态性DNA(RAPD)和微卫星两种分子标记技术分析了从法国 (F)、英国 (E)、西班牙 (S)引进我国的三个大菱鲆群体的遗传结构。 2 0个RAPD随机引物对每个群体各 2 0尾大菱鲆的基因组DNA进行扩增 ,共获得 1 2 5个重复性好且谱带清晰的RAPD标记 ,片段大小在 2 0 0— 2 5 0 0bp之间 ,三群体的多态位点比例在 1 2 80 %— 2 0 0 0 %之间 ,Nei基因多样性指数在 0 0 1 42— 0 0 35 2之间 ,Shannon多样性指数在 0 0 4 2 3— 0 0 72 0之间。微卫星引物的分析结果与RAPD一致。总体上 ,三个群体的遗传多样性均较低 ,其中西班牙群体遗传多样性水平最高 ,英国群体次之 ,而法国群体最低。利用Shannon多样性指数和Nei多样性指数估算群体遗传变异的来源 ,两者得出一致的结论 :群体间遗传分化很弱。AMOVA分析结果进一步证实了Shannon多样性指数和Nei基因多样性指数的分析结果 :群体的遗传变异有 97%以上是由群体内个体间的遗传变异引起的 ,遗传变异主要来自于群体内个体间 ,显著性检验表明群体间的变异对总变异的影响不显著。
Random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) molecular markers were used to detect genetic diversity, genetic structure and genetic divergency among three populations of Scophthalmus maximus L. imported from England, France and Spain (June 2002). Genetic DNA was extracted from muscle of the 60 S. maximus L. Inter-stock genetic similarity and intra-stock genetic similarity was then analyzed. Thirty random primers were used for analysis of nuclear DNA polymorphism of the three populations. Results showed that twenty primers were effective. 20 RAPD primers together produced 125 reproducible bands ranging from 200bp to 2500bp. The mean percentage of polymorphic loci of the three populations ranged from 12.80%-20.00%, while Nei's gene diversity was between 0.0142 and 0.0352. The average Shannon's indices of population phenotype ranged from 0.0423 to 0.0720. All these polymorphic indices revealed genetic diversity between the populations differing from each other. Shannon indices suggested that differentiation of S. maximus L. were divided into two parts, 1.05% from inter-populations and 98.95% from intra-populations. Hierarchy analysis of the population verified Shannon indices, 98.81% of the variance was from intra-populations. Concurrently, results of Analysis of Molecular Variation (AMOVA) revealed that the variance of inter-population hadn't significantly affected the total variance of S. maximus L. AMOVA (Analysis of Molecular Variation) analysis verified Shannon indices and Nei's gene diversity, over 97% of the variance was from intra-populations. At the same time, results of AMOVA revealed that the variance of inter-populations did not affect the total variance of S. maximus L. Results of SSR analysis including mean percentage of polymorphic loci, Nei's gene diversity and average Shannon's indices of phenotypic were all consistent with the results of RAPD revealing low genetic diversity of S. maximus L. populations. The lowest genetic diversity was in French population while the highest was in Spanish. Genetic distance of the three populations by RAPD analysis was 0.0124 to 0.0192 consistent with results of SSR. By comparing the results of RAPD and those of SSR, SSR was found to be more sensitive than RAPD in revealing polymorphism. SSR can reflect a higher level of genetic diversity than RAPD. In terms genetic similarity and distance, differences were seen between the results obtained from each method. Genetic diversity revealed by SSR was higher than that obtained by RAPD. As a whole, the results for population genetic structure detected by RAPD and SSR were consistent, yet a slight difference appeared with in intra-population genetic diversity, mainly due to differences in genetic variance detection abilities of the two techniques. All results here suggest that genetic diversity of imported turbot populations was very low. Thus, measures must be taken to avoid inbreeding depression of S. maximus L. in domestic populations in China.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2004年第4期332-341,共10页
Oceanologia Et Limnologia Sinica
基金
国家"8 6 3"计划资助项目
2 0 0 1AA6 2 0 2 0 7号
关键词
大菱鲆
种群
RAPD
微卫星
遗传变异
Turbot Scophthalmus maximus L., Population, RAPD, SSR, Genetic diversity
