转两类抗虫基因棉花优良纯合品系的选育

 用含合成的Cry1Ac杀虫蛋白嵌合基因 (Bt2 9K)及慈菇蛋白酶抑制剂B(API B)基因表达框的双抗虫基因植物表达载体 ,通过根癌农杆菌介导转化棉花生产品种冀合 32 1,获得了一批抗卡那霉素的转化再生植株。在对转化再生植株进行PCR、卡那霉素抗性和抗虫性测定的基础上 ,经 6代筛选培育出棉铃虫抗性 90 %以上且农艺性状优良的 9个转双抗虫基因棉纯合品系。各纯合株系子代植株的抗虫性及部分序列检测结果进一步表明上述Cry1Ac嵌合蛋白基因是能稳定遗传的。这些品系具有很好的农艺性状 ,其结铃性和纤维比强度明显高于转化受体冀合 32 1,这些纯合系可直接用于生产或作为双抗虫棉种质利用。

Selection of Homozygous Cotton Lines Transformed with Two Types of Insect-resistant Genes

A plant expression vector containing a chemeric Bt29K gene coding for the activated Cry1Ac protein and the arrowhead proteinase inhibitor gene API B was introduced into an elite cotton cultivar Jihe321 mediated by Agrobactertium tumefaciens . Based on the results of kanamycin resistant test, PCR detection for both foreign genes and insect bioassay using Heliethis armigera , nine transgenic homozygous cotton lines with insect resistance of more than 90% and better agronomic traits were bred through six generations of selection of the original transgenic plants. Results from insect bioassay and sequence analysis of the PCR products of plants from some homozygous lines indicated that the chimeric Bt29K gene had been stably inherited in these transgenic cotton lines. The main agronomic characters of these homozygous lines, such as boll productivity and fibre strength, were better than that of the original cotton cv. Jihe321. These homozygous lines can be applied directly or can be used as elite germplasm in breeding of new insect resistant cotton cultivars.