结球甘蓝抗虫转基因植株及其后代的抗性表现

应用农杆菌介导法将含有豇豆胰蛋白酶抑制剂 (CpTI)基因和新霉素磷酸转移酶 (NPTⅡ )基因的重组质粒导入结球甘蓝栽培品种春甘蓝“鸡心 2 3”和秋甘蓝“黑叶头”。对转基因当代植株 (T0 )及其自交后代 (T1、T2 、T3)群体进行卡那霉素抗性、抗虫性鉴定和分子检测。经PCR DNA分子杂交检测 ,确认抗虫基因———豇豆胰蛋白酶抑制剂基因已整合到受体植株的基因组中 ,并在有性生殖过程中传递给后代。卡那霉素抗性和抗虫性状在T0 代植株上得到表达 ;T1代植株中发生分离 ;T2 代中呈现出 3种不同类型的株系 :抗性纯合、杂合型和敏感性纯合株系 ;从T3 代中获得卡那霉素抗性和抗虫性纯合的株系。试验结果显示 ,卡那霉素抗性和抗虫性状在转基因植株自交后代中的表现基本符合显性单基因的分离规律。在T2 、T3 代抗虫性纯合的株系中 ,鳞翅目小菜蛾、甜菜夜蛾和斜纹夜蛾的 1～ 2龄幼虫校正死亡率为 6 %～ 10 0 % ,从中选出一批校正死亡率达 80 %左右的单株

Resistant Characteristics of Insect-resistant Transgenic Plants and Progenies of Cabbage

Through an agrobacterium-mediated transformation，the recombinant plasmids carrying CpTI gene and NPT Ⅱ gene were introduced into hypocoty1 segments of two cabbage （Brassica oleracea L．var．capitata）varieties-"Jixin 23" and "Heyeto"．Regenerated plants with kanamycin-resistance and insect-resistance were selected in T0 generation．PCR-DNA hybridization showed that CpTI gene was integrated into genome of the acceptor plants and genetically delivered to their progenies．Segregation of kanamycin-resistance and insect-resistance was observed in T1 generation.Three phenotypes：the homozygous line of resistance，heterozygosis line and homozygous line of sensitivity were exhibited in T2 generation.The homozygous lines of kanamycin-resistance and insect-resistance were obtained in T3 generation．Results indicated that the behaviours of kanamycin-resistance and insect-resistance in the transgenic plants and progenies were conformed to Mendelian Law of the dominant single gene segregation．Identification of insect-resistance showed that the transgenic plants carried outstanding resistance to Plutella xylostella（Linnaeus），Laphygma exigua Hübner and Prodenia litura Fabricius．The corrected mortalities of first or second instar larvae ranged 6％～100％ in T2 generation and T3 generation.A number of single plant with 80％ insect-resistance were selected．