摘要
以浙江乐清泥蚶养殖群体为育种基础群,经过2代连续选育获得了泥蚶快速生长品系,生长对比试验发现其在壳长、壳高、壳宽、总体质量等性状上都表现出了显著的生长优势。为了研究快速生长品系的遗传结构并筛查生长性状相关的分子标记,利用AFLP标记技术对泥蚶快速生长品系和对照组群体的基因组DNA进行了PCR扩增和电泳检测。采用40对多态性丰富的引物组合在64个个体中共扩增出2180条带谱,扩增位点总多态性比例达85.6%。从Nei’s基因多样性和Shannon’s信息指数反映的遗传多样性来看,选育品系的遗传多样性略高于对照组群体。群体遗传分化系数GST(0.0224)和基因流Nm(22.2811)数据显示,两群体间遗传变异很小,存在明显的基因流动。通过比对AFLP指纹图谱的位点差异,在2180条扩增带中共筛选出了7个显著性差异位点,其中2个位点只在选育品系中出现,2个位点在选育品系中出现的频率极显著高于对照组(P<0.01),另有3个位点在对照组中出现频率显著高于选育品系(P<0.05)。据此初步确定这些位点为与生长性状相关的候选标记。
The bloody clam, Tegillarca granosa, is an important commercial bivalve which is extensively cultured from South Korea to Malaysia. Due to its economic value, it is important to cultivate rapid growth strains for the sustainable development of aquaculture industry of T. granosa. The emergence of molecular markers provides a rich theoretical basis for the rapid cultivation varieties. By the method of group selec-tion, the rapid growth strains of T. granosa were bred though two generations. According to the compari-son test, the rapid growth strains showed significant advantages in shell length, shell height, shell width and total weight than control group under the same environmental conditions. AFLP marker was applied in this study to evaluate the genetic variation of the rapid growth strains, and to screen the molecular markers associated with the traits of growth. A total of 2180 bands were amplified from 64 individuals of the rapid growth strain and control group by 40 primer combinations. The analysis of Nei’s genetic diversity index and Shannon’s genetic information index of two groups indicated that the genetic diversity of breeding group was slightly higher than the control group. The genetic distance between two groups was about 0.011 3, the value of GST was 0.022 4 and Nm was 22.281 1, from which we concluded that there is a little genetic differentiation after selection. Of all amplified bands, 7 bands showed significant differences in frequency between two groups. 2 bands of all were only found in rapid growth strains, with the frequency of 0.812 5 and 0.343 8, respectively. And 2 bands showed significantly higher frequencies in rapid growth strains, while 3 bands showed significantly higher frequencies in control group. The bands with higher frequencies in rapid growth strains may be associated with the traits of growth. The unique AFLP markers associated with growth traits would be useful for growth-related gene cloning, quantitative trait locus （QTL） mapping, and molecular-assisted selection
出处
《水产学报》
CAS
CSCD
北大核心
2012年第6期825-831,共7页
Journal of Fisheries of China
基金
国家现代贝类产业技术体系(nycytx-47)
宁波市科技局农业择优委托项目(2010C10011)
温州市重大科技项目(S20080019)
关键词
泥蚶
生长性状
扩增片段长度多态性
遗传变异
Tegillarca granosa； growth traits； amplified fragment length polymorphism（AFLP）； genetic variation
