为研究抗虫杂交棉苏杂6号抗虫亲本YL02⁃1的Bt抗虫基因类型，抗虫性状遗传方式以及Bt基因在染色体上的插入位置，首先利用特异引物对抗虫亲本YL02⁃1的Bt基因来源进行PCR鉴定，结果显示，其扩增条带符合国产Bt抗虫基因引物设计的特征片段长度456 bp。而后以抗虫亲本YL02⁃1与非抗虫海岛棉种质系海7124杂交配组获得F1，F1自交获得F2分离群体。对F2分离群体的分析结果显示，Bt抗虫基因符合3∶1理论分离比例。进一步利用F2中含有Bt和不含Bt基因的棉株DNA构建近等基因混合池，以覆盖棉花26对染色体的234对核心引物检测混合池，共获得38对SSR多态性引物。将获得的多态性引物检测 F2分离群体基因型，发现分子标记NAU2579与目的基因连锁。已知分子标记NAU2579位于棉花第20染色体，对该分子标记上、下50 cM之内的其他分子标记进行多态性筛选，共获得17个与Bt基因连锁的分子标记，目的基因位于分子标记Gh564和NAU3813之间，其遗传距离分别为2�8 cM和12�2 cM。由此，将亲本YL02⁃1中的Bt抗虫基因定位于棉花第20染色体上。%To determine the Bt gene types, the inheritance of insect resistance traits, and chromosomal position of Bt gene in parental cotton material YL02⁃1, insect⁃resistant hybrid cotton Suza No.6, Bt genes were firstly identified by PCR using specific primers. The PCR product was 456 bp in length, the same size as domestically⁃bred insect⁃resistant Bt⁃transgenic cotton GK19. Then, F1 generation derived from the cross between insect⁃resistant parent YL02⁃1 and non⁃insect⁃resistant island cotton Hai7124 generated the F2 segregating population through selfing. The Bt⁃harboring plants in F2 population and non⁃harboring plants showed a 3∶1 segragation ratio, indicating that the insect resistance was controlled by a pair of domi⁃nant genes. A total of 38 pairs of SSR polymorphic primers were selected by detecting the mixed gene pool with 234 pairs of primers covering 26 chromosomes, among which, primer NAU2579, found to link to the target Bt gene in F2 generation, was located on chromosome 20. The target gene was located between SSR markers Gh564 and NAU3813,with genetic dis⁃tance of 2�8 cM and 12�2 cM respectively. Thus, the insect⁃resistant Bt gene from the parent YL02⁃1 is mapped on the cot⁃ton chromosome 20.
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