Determination And Analysis Of The Hazard Quotient(HQ)of Three Bt Rice Lines To Nontarget Organisms

Transgenic insect-resistant crops expressing insecticidal proteins from Bacillzus thuringiensis(Bt)have provided huge economic and environmental benefits.But it also has potential safety risks to the ecological environment while bringing huge benefits.Therefore,it is necessary to systematically evaluate whether transgenic insect-resistant crops is harm to the non-target organisms(NTOs)before commercial planting.We apply the hazard quotient(HQ)of pesticide risk assessment to ecological risk assessment of non-target organisms of Bt rice,and simplify the process of ecological risk assessment of Bt rice.We have determined no observed adverse effect concentrations(NOAECs)of three types of Bt proteins(CrylAb,Cry2A and Cry1C)for eight kinds of non-target organisms in artificial diets under laboratory conditions,as well as we have determined concentrations of Bt proteins in leaves,stems,pollen and seeds in the three kinds of Bt rice(KMD2,T1 C-19 and T2A-1)in seedling stage and tillering stage,jointing stage and heading stage and mature stage,and then calculated the estimated envirornmental concentrations(EECs).The hazard quotient(HQ=EECs/NOAEC)of three Bt rice for eight non-target organisms have been further calculated.In addition Nasonia vitripennis was applied to verify the results.The results are as follows:1.Determination of the hazard quotient of three Bt proteins against non-target organisms.As indicator organisms.Nilaparvata lugens,Nephotettix bipunctatus,Cyrtorhinus lividipennis,Harmonia axyridis,Bombyx mori,Tribolium castaneum,Nasonia vitripennis and Habrobracon hebetor,are used to measure the hazard quotients.The results showed that hazard quotient of the three Bt rice for eight non-target organisms was less than 1,indicating that three Bt rice had no potential risk to the non-target organisms.2.The effecs of three Bt proteins under the concentration of NOAEC on the biological parameters of Nasonia vitripennisAfter measuring NOAEC.three Bt proteins(CrylAb,Cry2A and Cry1C)under the concentration of NOAEC are added in the artificial diet of N.vitripennis.After feeding the artificial diet,the longevity of female adult,parasitic rate and reproduction of N.vitripennis showed no significant difference with control.It testifies that NOAEC is reliable.So,the result that the Bt rice lines KMD2,TIC-19 and T2A-1,respectively,are safe for the non-tagret model organism N.vitripennis is authentic.