Data/hora: 09/06/2024 04:23:24

Biblioteca(s): | Embrapa Soja.
Data corrente: | 07/04/2004
Data da última atualização: | 27/07/2007
Autoria: | LEVY, S. M.; FALLEIROS, A. M. F.; MOSCARDI, F.; GREGÓRIO, E. A.
Título: | Is the nucleopolyhedrovirus of Anticarsia gemmatalis (AgMNPV) ineffective to infect AgMNPV resistant host larva midgut cells?
Ano de publicação: | 2004
Fonte/Imprenta: | In: WORLD SOYBEAN RESEARCH CONFERENCE, 7.; INTERNATIONAL SOYBEAN PROCESSING AND UTILIZATION CONFERENCE, 4.; CONGRESSO BRASILEIRO DE SOJA, 3., 2004, Foz do Iguassu. Abstracts of contributed papers and posters. Londrina: Embrapa Soybean, 2004.
Páginas: | p. 293.
Série: | (Embrapa Soja. Documentos, 228).
Idioma: | Inglês
Notas: | Editado por Flávio Moscardi, Clara Beatriz Hoffmann-Campo, Odilon Ferreira Saraiva, Paulo Roberto Galerani, Francisco Carlos Krzyzanowski, Mercedes Concordia Carrão-Panizzi.
Conteúdo: | Anticarsia gemmatalis is a key pests of soybean in Brazil. It has been controlled by a nucleopolyhedrovirus (AgMNPV), which is widely used as a microbial insecticide in the country. The constant and increase use of this biological insecticide in some regions have caused concerns about the possibility of selection of viral resistant populations. Although this phenomenon has not been detected in the field yet, a laboratory A. gemmatalis populations has been selected for high resistance to the AgMNPV. It is known that midgut is considered one of the most important barriers against viral invasion, before systemic infection can be caused in various tissues if the virus succeeds in reaching the host larvae hemocele. Our work aim to verify whether or not the AgMNPV invades and infects the midgut cells of resistant larvae, comparing the ultrastructure of the midgut epithelial cells from the susceptible (SL) and resistant (RL) A. gemmatalis infected larvae. The susceptible and resistant strains of A. gemmatalis were reared on artificial diet, under laboratory-controlled conditions at Embrapa Soja, Londrina-PR, Brazil. The AgMNPV used as inoculum was incorporated into the insect diet at 60,000 oclusion bodies/ml of diet. The midguts were collected up to 120h post infection, processed and analyzed under transmission electron microscopy. The columnar cells were the most affected among the different midgut epithelial cells. In the SL, this cells shows many morphological signs of cellular damage from 24 hours after infection, mainly at the proximal midgut region. However in RL, this cells exhibited minor morphological damages up to 120 hours. Polyhedra were visualized in the midgut of both SL and RL from 96 hours of infection, but the amount of viral structure were always higher in SL, affecting the midgut epithelial cells and tracheal cells, as well as attached hemocytes (mainly plasmatocytes and granulocytes). Our results showed that the AgMNPV, in fact, invade RL cells. However, the virus did not affect these insects as they did with the susceptible ones, allowing development and survival of RL. The mechanism interfering with the virus infection progress in the midgut cells of RL is still unknown. This work has been supported by FAPESP and PRONEX (MCT/Finep/CNPq).
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (23766-1) - UMT - PL - -- - RF 633.34072 - W927a -  - DIS