| In order to evaluate the ecological security of transgenic cry1Ab maize,the direct observation method and the trap method were used to investigate species and quantity of non-target arthropods communities in transgenic insect-resistant maize field and non transgenic maize field in the two growing seasons.The effect of transgenic insect-resistant maize on biodiversity of non-target arthropods in the field was analyzed.In order to evaluate insect resistance of transgenic cry1Ab maize,Enzyme-Linked Immunosorbent Assay(ELISA)was used to determine the contents of Bacillus thuringiensis(Bt)CrylAb protein in different organizations of transgenic insect-resistant maize and different stages,The spatiotemporal expression of CrylAb protein in transgenic insect-resistant maize was definited.At the same time,the insecticidal effects of transgenic cry1Ab maize to neonates of Ostrinia furnacalis Guenee,Helicoverpa armigera Hubner and Mythimna seperata Walker were tested in the laboratory and field.The main results were as follows:1.The biodiversity of non-target arthropods in maize fields was investigated by the direct observation and the trap survey in 2018 year and 2019 year.During the two growing seasons,there was no significant difference in the non-target total biomass,total species,biodiversity index,evenness index and dominance index between the transgenic maize field and the non transgenic maize field.2.The measured results of Cry1Ab protein at different stages of transgenic insect-resistant maize showed that the content of CrylAb protein in the grain filling stage was the highest,then followed by seedling stage,silking stage,jointing stage and bellmouth stage.The CrylAb protein content of the functional leaf at the filling stage was 827.62 ng/g.The CrylAb protein content of the seedling stage and silking stage were 580.00 ng/g.The Cry1Ab protein content of the jointing stage and bellmouth stage were 300.00 ng/g.In the same stage of maize,The CrylAb content in root was the highest,followed by the functional leaf,the content of the stem was lowest.In the silking stage,for example,the content of CrylAb protein was 1528.27 ng/g in roots,578.40 ng/g in functional leaves and 421.58 ng/g in stems.At the later stage of growth,the Cry1Ab protein content in grains was relatively low due to the transfer of growth center,and the Cry1Ab protein content in grains at the ripe stage was 251.95 ng/g.3.The resistances of the transgenic cry1Ab maize to three species of corn pests were determined in the laboratory and field respectively.The results showed that the transgenic cry1Ab maize to O.furnacalis,H.armigera and M.seperata exhibited all high resistance in field.The laboratory bioassay results showed that the transgenic insect-resistant maize had a high resistance to O.furnacalis neonates with more than 70%death rate in 3 d.The leaves and seeds of transgenic insect-resistant maize were highly resistant to H.armigera neonates with the more than 80%death rate.The filament was only intermediate resistant to H.armigera neonates with 50%death rate in 3 d.Although the transgenic insect-resistant maize had a low insecticidal activity to M.seperata neonates,it could inhibit the growth and development of M.seperata,and the weight was significantly declined.The average weight of M.seperata neonates fed on transgenic maize was 5.90±1.73 mg on the 7th day,while that fed on non transgenic maize was 62.00±5.24 mg on the 7th day.The inhibition rate of weight was 90.48%. |
