摘要： 基于PCR的DNA指纹鉴定技术AFLP广泛应用于生物多样性、遗传图谱构建、基因定位、分子系统发育和品种鉴定等方面.为了筛选出大白菜适宜的AFLP引物组合,研究以抗根肿病大白菜双单倍体CR Shinki、感病自交系94SK及其后代F2构成的纯合抗病和纯合感病DNA混合池为材料,利用25对Pst I/Mse I引物组合进行了AFLP分析.结果表明:平均每个组合检测到55条带,共扩增13 079条带,平均每1 000条带检测到1.30个根肿病抗性基因连锁标记;多态性带数为3 17条,双亲间多态性频率约为0.24;扩增带数与多态性带数呈线性正相关,引物组合中的不同GC含量与扩增带数和多态性带数存在显著性差异,并表现出线性负相关.筛选出的适宜53对引物组合共扩增出4 381条带,占总扩增片断的33.50%,平均每对扩增出83条,其中9个组合扩增出与抗根肿病基因连锁标记.

关键词: 大白菜, AFLP, 引物组合, GC含量

Abstract: The PCR-based DNA fingerprinting technique AFLP is widely used in analysis of genetic diversity, the construction of linkage maps, gene mapping, molecular phylogeny and cultivar identification. In this study the clubroot resistant CR DH line, suscept ible inbred line 94SK of Chinese cabbage, the resistant and susceptible DNA bulks constructed from F2 individuals of CR DH line and 94SK were used to select the adaptive AFLP primer combinat ion. AFLP analysis was performed with 256 Pst I/ Mse I primer combinat ions.The result indicated that 237 combinations amplif ied a total of 13 079 AFLP fragments with an average of 55 fragments, the average of 1. 30 markers per 1 000 AFLP fragments were found to be linked to clubroot resistant gene; the amplified polymorphic fragments were 3 167 between the two parents, account for 24 percent of polymorphic frequency; the number of amplified fragments and the number of polymorphic fragments was in pos-i tive linear correlation; GC content of AFLP primer combinat ions significantly affects the number of amplified fragments and the number of polymorphic fragments, indicating negative linear correlat ion between them. Fifty-three primer combinations were found to amplify nuclear DNA of Chinese cabbage, properly. They amplified the fragments up to 4 381 with an average of the 83.Among them, 9 markers derived from 9 primer combinations were linked to the clubroot resistance gene.

Key words: Chinese cabbage, AFLP, Primer combination, GC content

中图分类号: 

• Q78