| In this paper, laboratory feeding experiments using transgenic corn expressing aCry!Ab protein derived from Bacillus thuringiensis (Berliner) subsp. Kurstaki onnon-target insect, corn leaf aphis, Rhopalosiphum maidis Fitch , and its predator,Propylaea japonica (Thunberg) were carried on in laboratory. Host plants were threetransgenic Bt corn hybrids, MON810, Bt11 and 176, and their nontransgenic isogenicB. thuringiensis free corn hybrids. The levels of the transgenic CryIAb in R. maidisfeeding on Bt corn and P. japonica feeding on Bt pollen are analyzed by using aquantification assay (ELISA). It will be helpful to evaluate the ecological risks of thetransgenic crops resistant to insects and take full advantage of the transgenic crops inIPM. The results are shown as follows:1. The effect of Bt corn on the survival rate, fecundity and intrinsic rate of thepopulation increase of corn leaf aphid experimental population was studied inlaboratory. There were no significant difference in developmental time, fecundity andsurvival rate of R. maidis between the MON810, Bt11 and their non-transgenic corn,respectively. No significant difference were observed in the rate of alatae, themortality of immature, the longevity, the days for fecundity and the ecdysis rate ofcorn leaf aphid when feeding on Bt and non-Bt corn hybrids.2.There was no obvious difference in total mean survival rate from hatch to adulteclosion between P. japonica nymphs reared on B. thuringiensis-fed or B.thuringiensis-free prey. The pupation of P. japonica reared on B. thuringiensis-fed orB. thuringiensis-free prey is no difference. No significant difference in totaldevelopmental time and mean weight of the adults were detected between P. japonicareared on B. thuringiensis-fed or B. thuringiensis-free prey. So no lethal or sublethaleffects were observed when P. japonica were reared on B. thuringiensis-fed preycompared with the B. thuringiensis-free control.3. Provided different corn pollen to P. japonica and following completion of the1st instar individuals were given a corn leaf aphis at the beginning of 2nd ,3rd and 4thinstar stages, the survival is very low. So a modified method to provide a R. maidisthe every other day for P. japonica nymphs reared on corn pollen was adopted and thesurvival of P. japonica was increased. There was no difference in the survival of 1stinstar P. japonica between the Mon810, and Bt11 and their corresponding non-Btisogenic corn hybrid, respectively. And no difference was observed in the total meanmortality, ecdysis rate and weight of 2nd instar P. japonica between the treatments.The significiently higher mortality of 3rd instar P. japonica appeared to have norelation to Bt toxin, because the mortality of P. japonica reared on B. thuringiensiscorn pollen was lower than reared on non-Bt corn pollen before 13th days, andsignificant difference was observed in pupation and emergence. There was nodifference in the mortality, pupation and emergence of 4th instar P. japonica betweenthe treatments. So no acute detrimental effects were observed when P. japonica werereared on Bt corn pollen compared with non-Bt corn pollen.4. The quantity of Cry1Ab in R. maidis reared on Bt corn in different days ordifferent generatings, and the P. japonica,s nymphs of different instars were conducted,and there was significant difference between the Cry1Ab in R. maidis reared on Btcorn and non-Bt corn. The Cry1Ab protein is more higher in R. maidis reared on Btcorn. The Cry1Ab protein is obviously higher in P. japonica,s reared on Bt corn pollenthan non-Bt corn pollen.There is only little Cry1Ab protein in the R. maidis which collected from Bt cornplants in field, and have great difference among MON810 and other corn varieties.
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