Bt-Cry5Aa 基因转化棉花及其抗虫性鉴定

我国棉花抗虫基因大都为Cry1Ab/c,抗性风险日趋增加。本研究依据棉花密码子偏好,人工合成Bt-Cry5Aa抗虫基因,通过花粉管通道法转入棉花,并通过卡那霉素法及PCR方法对不同世代转化株进行鉴定,同时进行了抗虫性测试。结果表明,通过花粉管通道法成功获得转Bt-Cry5Aa基因植株,通过田间卡那霉素鉴定,阳性株率T1为7.76%,T2为73.1%,T3为95.5%;PCR检测显示,T1阳性率为2.35%,T2为55.8%,T3为94.5%;田间抗性试验分析,转Bt-Cry5Aa株系对第2、3、4代棉铃虫校正死亡率分别达到85.42%、75.35%和62.79%,其抗虫性与GK19相比差异不显著;Bt-Cry5Aa能够部分替代目前主流鳞翅目抗虫基因,是棉铃虫的新抗源。

Transformation of Cry5Aa BT in Cotton and Identification of its Insect-resistant

Almost all insect-resistant genes applied in China is Cry1Ab/c and the resistance risk is increasing. Cry5Aa insect-resistant gene was synthesized according to the codon preference of cotton, it is transformed through pollen tube pathway into cotton plants, and it is identified through Kanamycin test, PCR and insect resistance test for different generation in the paper. The main results are shown as following: Firstly, transgenic plants of Cry5Aa were gotten successfully by pollen tube pathway method, and gene transformation efficiency of T1generation, T2 generation T3 generation was 7.76%, 73.1%, 95.5%, respectively. Secondly, results of identification of PCR showed that the positive rate of transgenic plants in T1 generation, was 2.35%, and 55.8% in T2 generation. Thirdly, corrected mortality rates of second, third and fourth generation of cotton bollworm for these transgenic plants was 85.42%, 75.35% and 62.79%, respectively, and the difference between these Cry5Aa insect-resistant transgenic plants and GK19 is not significant. Lastly, all above results indicate that Cry5Aa Bt can replace the current insect-resistant genes, and it is an ideal source for bollworm resistance.