Effects of straw extracts of Bt transgenic maize on germination of wheat

This study was to analyze the effects of different concentrations of two maize(transgenic Bt maize and non-transgenic maize) straw extract on germination and seedling growth of wheat.All experiments were investigated by means of bioassay in laboratory.The results showed that both maize straw extract at low concentration(1∶100) had no significant effect on wheat germination while high concentration(1∶25) inhibited seed germination,especially treated by transgenic Bt maize straw extract.At 1∶100 concentration transgenic Bt maize straw extract significantly increased seedling height and root length,which reached 9.7 and 10.84 cm respectively.However,non-transgenic maize straw extract at concentration of 1∶25 significant decreased seedling height(6.9 cm) and root length(4.28 cm),transgenic Bt maize straw could release Bt protein into aqueous extract,but there was no influence on wheat germination when seed soaked in Bt solution for 24 h.Therefore,a certain proportion of Bt-maize straw ploughed into soil has no adverse affect on germination of the following crop.