Bacillus thuringiensis monogenic strains: screening and interactions with insecticides used against rice pests

Brazilian Journal of Microbiology

Laura M.n. Pinto²  Natália C. Dörr²  Ana Paula A. Ribeiro²  Silvia M. De Salles²  Jaime V. De Oliveira¹  Valmir G. Menezes¹  Lidia M. Fiuza² 

[1] ,Universidade do Vale do Rio dos Sinos Programa de Pós-Graduação em Biologia Laboratório de Microbiologia e ToxicologiaSão Leopoldo RS ,Brasil

关键词: Bacillus thuringiensis;    Cry proteins;    Insects;   

DOI  :  10.1590/S1517-83822012000200025

来源: SciELO

【 摘 要 】

The screening of Bacillus thuringiensis (Bt) Cry proteins with high potential to control insect pests has been the goal of numerous research groups. In this study, we evaluated six monogenic Bt strains (Bt dendrolimus HD-37, Bt kurstaki HD-1, Bt kurstaki HD-73, Bt thuringiensis 4412, Bt kurstaki NRD-12 and Bt entomocidus 60.5, which codify the cry1Aa, cry1Ab, cry1Ac, cry1Ba, cry1C, cry2A genes respectively) as potential insecticides for the most important insect pests of irrigated rice: Spodoptera frugiperda, Diatraea saccharalis, Oryzophagus oryzae, Oebalus poecilus and Tibraca limbativentris. We also analyzed their compatibility with chemical insecticides (thiamethoxam, labdacyhalothrin, malathion and fipronil), which are extensively used in rice crops. The bioassay results showed that Bt thuringiensis 4412 and Bt entomocidus 60.5 were the most toxic for the lepidopterans, with a 93% and 82% mortality rate for S. frugiperda and D. saccharalis, respectively. For O. oryzae, the Bt kurstaki NRD-12 (64%) and Bt dendrolimus HD-37 (62%) strains were the most toxic. The Bt dendrolimus HD-37 strain also caused high mortality (82%) to O. poecilus, however the strains assessed to T. limbativentris caused a maximum rate of 5%. The assays for the Bt strains interaction with insecticides revealed the compatibility of the six strains with the four insecticides tested. The results from this study showed the high potential of cry1Aa and cry1Ba genes for genetic engineering of rice plants or the strains to biopesticide formulations.

【 授权许可】

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