转cry1Ab/cry2Aj玉米对亚洲玉米螟的抗性评价

为探讨转cry1Ab/cry2Aj玉米对亚洲玉米螟Ostrinia furnacalis(Guenée)的抗性,采用室内生测和田间人工接虫鉴定方法评价了6个转cry1Ab/cry2Aj玉米品系对亚洲玉米螟的杀虫效果,并利用酶联免疫吸附法(ELISA)测定了Cry1Ab蛋白在各品系主要组织的表达水平.结果显示,亚洲玉米螟幼虫取食转基因玉米各品系雄穗、苞叶、花丝和雌穗48 h后死亡率在90％左右,取食心叶的死亡率在70％左右,96h后大部分幼虫死亡,而取食非转基因玉米的死亡率为3.3％～8.7％;春播和夏播田转基因玉米叶片、茎秆、雌穗基本没有被害,而对照玉米叶片、茎秆、雌穗被害严重,春播和夏播玉米平均每株分别有2.9、2.3头幼虫和蛹,2.8、3.4个蛀孔,隧道长度为7.5、14.2 cm,雌穗被害级别为5.3和5.1;6个转基因玉米品系中Cry1Ab蛋白在心叶、雄穗、花丝、苞叶和雌穗中稳定表达.综合评价认为,转基因玉米各品系在整个生育期内对亚洲玉米螟有很好的抗性,其中N50品系抗虫效果最佳,可以作为抗虫转多基因玉米育种的备选材料.

Evaluation of transgenic cry1Ab/cry2Aj maize for its resistance to Ostrinia furnacalis

In order to assess the control efficacy of transgenic cry1Ab/cry2Aj maize to Ostrinia furnacalis(Guenée), six events of transgenic cry1Ab/cry2Aj maize were evaluated through laboratory bioassay and artificial infestation in field test, and the levels of Cry1Ab protein expressed in main tissues of transgenic maize were measured using enzyme-linked immunosorbent assays. The results showed that the mortalities of O.furnacalis neonate larvae were around 90.0% when fed on tassels, husks, silks, kernels of transgenic maize events, around 70.0% when fed on whorl leaves 48 h after infestation, and most larvae could survive no longer than 96 h. The mortalities of neonate larvae fed on non-transgenic control were 3.3%-8.7%. There were no significant damages of leaves, stalks and kernels in transgenic maize plants in spring and summer crop seasons, compared with severe damages of leaves, stalks and kernels in non-transgenic control plants with an average number of 2.9 and 2.3 larvae (or pupae) per plant, 2.8 and 3.4 tunnels per stalk, an average length of 7.5 and 14.2 cm of damaged tunnel, as well as 5.3 and 5.1 ear damage ratings. Additionally, the expression levels of Cry1Ab protein in whorl leaves, tassels, silks, husks and kernels of these six transgenic maize events were stable. In conclusion, these transgenic cry1Ab/cry2Aj maize events could provide protection against O.furnacalis for the whole season, and the event N50 offered the highest insect resistance and could serve as breeding source for the development of insect-resistant pyramided transgenic maize.