可去除选择标记的转Bt基因抗虫玉米研究

将组成型表达的玉米泛素启动子与苏云金杆菌杀虫蛋白基因Bt连接，插入根瘤农杆菌双T-DNA质粒，构建一个T-DNA结构域含有抗潮霉素选择标记基因hyg，另一个T-DNA结构域含有抗虫基因的双T-DNA单子叶植物表达载体，用以转化农杆菌菌株，再通过共培养转化玉米胚性愈伤组织。通过潮霉素培养基抗性筛选，用特异PCR扩增和Southern杂交检测，从分化再生的T0代植株中，鉴定出4个转化Bt基因的阳性植株。目前，正结合进行田间分离纯合和DNA分子鉴定，培育去除选择标记基因的转基因抗虫玉米自交系。

Study on Bt Transgenic Insect Resistant Maize with Removable Selective Marker

Insecticidal protein gene of Bacillus thuringiensis(Bt), promoted by ubiquitin promoter of constitutive expression, was inserted into double T-DNA plasmid of Agrobacterium tumefaciens. Monocotyledonous expression vector of double T-DNA was constructed with selective marker gene hyg (hygromycin resistance) in one T-DNA structural domain and insect resistant gene in another T-DNA domain. Agrobacterium strain was transformed with this vector and used to transform embryonic callus of maize by co-culture. Four Bt transgenic plants were identified from differentiated and regenerated T0 population through resistant selection on hygromycin medium and molecular detectin of specific PCR amplification and Southern hybridization. At present, inbred lines of transgenic insect resistant maize with selective marker gene removed are in separating and inbreeding program assisted by DNA marker detection.