Efficacy Evaluation Of Transgenic Maize Event DR 12-5 To Target Pests And The Risk Assessment To Non-Target Animals

Transgenic maize event DR 12-5 is a new generation of genetically modified maize varieties with complex traits independently developed by Zhejiang University.It is one of the important genetically modified maize varieties with commercial prospects in China.At present,it has been approved to enter the stage of production test.In the process of commercialization of GM maize,functional identification and impact assessment on non-target organisms are important components of safety assessment of GM plants.In this study,the insect resistance of maize was evaluated by combining bioassay with infecting insects,and the ecological safety of transgenic maize event DR 12-5 to non-target economic insects,bees,silkworms and soil biological earthworms was evaluated by feeding pollen,leaves and other plant materials.The resμlts show that:1.The highest expressed of Bt protein was leaves of 12-5,and the others from tall to low were in the following order:pollen,stamen,root and filament.Althoμgh the expressed protein content was different,it showed good resistance to corn borer in laboratory bioassay.2.Feeding Eisenia foetida with freeze-dried leaves of transgenic corn woμld not have negative effects on the survival,weight and reproduction of earthworms,nor would it cause abnormal activities of total protein,SOD,POD and CAT in earthworms.3.The Apis mellifera ligustica was fed with sμgar mixture of GM maize pollen and pure CryAb protein.The results showed that GM maize pollen and CryAb protein did not cause bee death compared with control treatment,but resμlted in a decrease in bee feeding.4.The Bombyx Mori Linnaeu was fed with different concentrations of GM maize pollen.The resμlts showed that the highest concentration of T-40 treatment could cause the death of the first-instar silkworm,and no death occurred in other treatments.Transgenic pollen treatment can reduce the development duration and weight of silkworm,and increasethe activities of SOD,POD and CAT in silkworm.But it had no effect on physiological indexes such as cocooning rate,emergence rate and cocoon weight.In summary,the transgenic maize 12-5 with CryAb/Ac and G10evo-epsps genes has excellent insect-resistance.It also does not threaten the safety of non-target insects such as bees,silkworms and earthworms of soil animals under natural conditions.