Suscetibilidade e interação de proteínas Cry1 e Vip3A de Bacillus thuringiensis para o controle de lepidópteros-praga

• Autor(a) principal: Crialesi, Paula Cristina Brunini [UNESP]
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/108500
• topic: Pragas agricolas - Controle biologico; Bactérias; Bacillus thuringiensis; Proteinas de bacterias; Lepidoptero; Agentes no controle biologico de pragas; Bacterial proteins

Chemical insecticides are widely used to control insect pests, however, cause enormous environmental damage. An alternative to these insecticides is the use of entomopathogenic microorganisms which selectively control insects and preserve the environment. The Bacillus thuringiensis Berliner is the species of greatest interest responsible for production of insecticidal proteins. Genes of B. thuringiensis have been widely studied and used in the construction of transgenic crops worldwide. However, when not associated with refuge areas can accelerate the selection of resistant organisms in populations of insect pests. Studies have reported the need to slow the evolution of resistance to insect pests and among the possibilities, the use of more than one gene in the construction of transgenic plants proves efficient. Thus, the present study evaluated the susceptibility of Anticarsia gemmatalis (Hübner, 1818) (Lepidoptera: Erebidae) and Chrysodeixis includens (Walker, 1857) (Lepidoptera: Noctuidae), from the proteins isolated from B. thuringiensis Cry1Aa , Cry1Ab , Cry1Ac , Cry1Ca , Cry1Ea , Vip3Aa , Vip3Ae and Vip3Af . After estimating the LC50 of each protein for each species evaluated the interaction between combinations of Vip3A + Cry1 and Cry1 + Cry1. The results suggest that all proteins were effective in controlling both species, emphasized the Cry1Ac protein (0.75 ng.cm-2) to A. gemmatalis and Vip3Af protein (1.4 ng.cm-2) to C. includens. A comparison of the susceptibility of the species to proteins indicated that there is a significant difference in toxicity for each species. There was a large inhibition of larval development of caterpillars surviving the LC50 of each protein. The interactions of proteins indicated the synergistic combinations Vip3Aa + Cry1Ea, Cry1Aa + Cry1Ab and Cry1Ea + Cry1Ac as alternatives for the control and management of resistance in A. gemmatalis and C. includens ...