小菜蛾对阿维菌素抗性基因的AFLP连锁图谱的构建

世界性害虫小菜蛾Plutella xylostella (L.) 田间种群已对阿维菌素药剂产生了高抗药性。本研究以小菜蛾对阿维菌素的抗性品系、敏感品系和回交群体组建作图家系，再利用AFLP技术构建小菜蛾对阿维菌素抗性基因的连锁图谱。用10组AFLP引物组合对未经药剂处理的小菜蛾成虫DNA选择性扩增，共获得1 044条可区分的DNA条带，271条带具有多态性，χ²检验表明只有123个位点符合1∶1 （P=0.05），其中的112个构成28个连锁群，其总长度为1 222.7 cM； 用10组AFLP引物对经药剂处理后存活的小菜蛾成虫DNA扩增，所得的DNA条带中有54个条带符合分离比1∶1，经Mapmaker 3.0对多态性位点分析，只有E1M4-15、E1M1-4和E1M4-2标记位点位于同一连锁群，3个AFLP标记与抗性基因的遗传距离分别为0 cM，8.3 cM和13.1 cM。比较分析得出，抗性基因所在的连锁群是第5连锁群。结果显示AFLP连锁图谱对小菜蛾对阿维菌素的抗性监测具有很好的应用潜力。

Linkage mapping of resistance to abamectin in the diamondback moth using AFLP marker

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is an important insect pest in cruciferous vegetables and has developed high resistance to avermectin all over the world. In this study, AFLP was used to construct a linkage map of resistance to avermectin in diamondback moth. The mapping families consisted of the susceptible strain, the abamectin-resistant strain and their backcross progeny. A total of 1 044 DNA bands and 271 polymorphic loci were amplified using 10 combinations of AFLP primers. Chi-square (χ²) analysis indicated that only 123 bands fit the segregation ratio of 1∶1 (P=0.05) in these polymorphic loci. Twenty-eight linkage groups were constructed with 112 bands, covering about 1 222.7 cM of the genomics of the diamondback moth. Three markers of E1M4-15, E1M1-4, and E1M4-2, linked with abamectin-resistant gene were situated on the same linkage group and their distance apart from resistant gene was 0 cM, 8.3 cM, and 13.1 cM, respectively. Comparison with the constructed linkage map showed that the gene was located on the fifth linkage group. These AFLP markers associated with resistance to abamectin show a strong potential of application in monitoring diamondback moth resistance to abamectin.