Trait Evaluation Of The Insect-resistant And Herbicide-tolerant Transgenic Maize ZD12-6

Maize[(Zea may L.)]is one of the most important crops,which serves as food and feed sources.But pest insects and weeds are causing significant damage to yield and quality of maize.Insect-and herbicide-resistant transgenic maize can significantly improve the pests and weeds control efficiency and reduce production costs.We evaluated insect resistance and herbicide tolerance of transgenic maize event ZD 12-6,which was developed by our lab at Zhejiang University.The transgenic maize contained a fusion Bacillus thuringiensis(Bt)insecticidal gene cry1Ab/cry2Aj and a glyphosate-tolerant gene G10evo-epsps.The Bt gene was obtained by fusing cry1Ab and cry2Aj genes,which extends the insecticidal spectrum.G10evo-epsps is a novel glyphosate-tolerant EPSPS,has a high glyphosate tolerance.In this study,ZD12-6 was tested in laboratory as well as field to evaluate the insect resistance and glyphosate tolerance and analyze expression levels of the target genes.The proteins of Cry1Ab/Cry2Aj and GlOevo-EPSPS were detected in the leaves,ears,bracts,tassels and silks of ZD12-6 by western blot.ELISA analysis showed that Cry1Ab/Cry2Aj and G10evo-EPSPS expression levels were the highest in leaves,with Cry1Ab/Cry2Aj expressed at a concentration of 17.8?g/g fresh weight and G10evo-EPSPS expressed at a concentration of 11.2?g/g fresh weight.Insect resistance assay in lab showed that the mortality rate of cotton bollworm(Helicoverpa armigera),oriental armyworm(Mythimna seperata),Asiatic corn borer(Ostrinia furnacalis)were 95.51%,73.13%,93.08%,after feeding ZD12-6 48h,which indicated that ZD12-6 had high insecticidal activity against cotton bollworm,oriental armyworm,Asiatic corn borer.Insect resistance assay in the field showed that ZD12-6 had high insecticidal activity against Asiatic corn borer.Glyphosate spraying assays both in the green house and in the field showed that ZD12-6 was tolerant to 4x recommended amount of glyphosate,and no significant difference in height was found between the transgenic maize and the non-transgenic maize,indicating that ZD12-6 has a strong glyphosate-tolerant capacity.The result of above studies show that ZD12-6 has high insecticidal activity and high levels of glyphosate resistance,and it also has great potential for commercial cultivation.