2个抗虫棉的外源Bt基因分子鉴定及其染色体定位

以中美2个抗虫棉品种GK19与33B为试验材料,利用检测中美Bt基因的特异性引物,分别对抗虫棉亲本GK19和33B进行PCR扩增,并通过SSR分子标记技术对其Bt基因进行分子鉴定与染色体定位,旨在从外源基因转化事件的视角探究中美转基因抗虫棉差异的分子基础。结果表明, GK19为中国转Bt基因抗虫棉, 33B为美国转Bt基因抗虫棉; GK19的Bt基因被定位在棉花Chr.20上,共16对SSR多态性标记与其Bt基因连锁,两侧的分子标记为NAU3907和NAU2579,其遗传距离分别为2.4 cM和1.5 cM; 33B的Bt基因被定位在棉花Chr.26上,共20对SSR多态性标记与Bt基因连锁,目标Bt基因位于标记NAU460和dc40260之间,其遗传距离分别为3.6 cM和2.0 cM。以上结果表明GK19和33B属于不同的遗传转化事件。

Molecular identification and chromosomal mapping of exogenous Bt gene in two insect-resistant cotton varieties

Molecular identification and chromosomal localization of Bt genes in two insect-resistant cotton varieties GK19 from China and 33B from the United States were conducted to explore the molecular basis of the differences between the two transgenic cotton varieties in perspective of exogenous gene transformation events. GK19 was a domestic Bt transgenic insect-resistant cotton variety, its Bt gene was located on cotton Chr.20, and linked to a total of 16 pairs of SSR polymorphic markers, flanking sides were markers NAU3907 and NAU2579 with genetic distance of 2.4 cM and 1.5 cM, respectively. The Bt gene in 33B was located on cotton Chr.26, with a total of 20 pairs of SSR polymorphic markers linking to the Bt gene, the target Bt gene was located between markers NAU460 and dc40260, with genetic distance of 3.6 cM and 2.0 cM, respectively. This study revealed that GK19 and 33B were from different transgenic events.