Abstract:

Effect of MSA and MSB, transgenic rice with fused genes of Cry1Ac and SCK, and 21S/MSB and II-32A/MSB, progenies from crosses between Cry1Ac/SCK-transgenic rice and conventional rice varieties on the pest insect community in paddy field was tested by the suction machine sampling method combined with the field denudation method. The results indicated that both MSA and MSB were highly resistant against the rice leaf roller, Cnaphalocrocis medinalis. The rice lines 21S/MSB and Ⅱ-32A/MSB also obtained the trait of high resistance to C. medinalis. Although MSA, MSB, 21S/MSB and II-32A/MSB showed some effect on the temporal dynamics of species richness, number of individuals, diversity, evenness and dominant concentration indices, the results from analysis of the whole period of rice growing revealed that the four rice varieties had no remarkable effect on the species richness, total number of individuals, diversity, evenness and dominant concentration indices of communities of pest insects in paddy fields compared with their respective control. Comparison of the results of different rice revealed high compositional similarities in the total and key pest insect species. The removal or depressing of population of target pest insect C. medinalis had negligible effect on the dominant species, composition, and structure of pest insect communities in paddy fields planted with Cry1Ac/SCK transgenic rice. 

Key words: Transgenic rice, biosafety, Cry1Ac, SCK, resistance to insects, community parameter