Resumo: O objetivo deste trabalho foi avaliar uma gama de hospedeiros, in vitro, quanto à resposta a Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), um vírus patogênico à lagarta-do-cartucho (Spodoptera frugiperda; Lepidoptera: Noctuidae), para o posterior desenvolvimento de um biopesticida baseado em sistema de cultura de células. As linhagens celulares de Bombyx mori (BM-5), Lymantria dispar (IPLB-LD-625Y), Trichoplusia ni (BTI-Tn-5B1-4), Anticarsia gemmatalis (UFL-AG-286) e S. frugiperda (IPLB-SF-21AE e Sf9) foram testadas quanto a sua suscetibilidade a um isolado brasileiro de SfMNPV altamente virulento. Os efeitos citopáticos induzidos pelo vírus, a produção de partículas virais e a síntese de polipeptídeos virais foram examinados e comparados. Ambas as células de S. frugiperda apresentaram hipertrofia dos núcleos celulares e produção de muitos poliedros. O SDS-Page de proteínas com radiomarcação mostrou que as proteínas celulares apresentaram inibição de síntese, enquanto uma intensa banda de cerca de 30 kDa, reconhecida como poliedrina, era sintetizada. As outras linhagens celulares não apresentaram produção de poliedros, apesar de algumas terem apresentado alterações morfológicas e inibição de síntese proteica em resposta à infecção viral. As linhagens celulares SF-21 e Sf9 são recomendadas para a posterior produção in vitro de SfMNPV.

Abstract: The objective of this work was to evaluate the response of an in vitro host range to Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), a pathogenic virus to the fall armyworm (Spodoptera frugiperda, Lepidoptera: Noctuidae), for the further development of a biopesticide based on cell culture systems. The cell lines from Bombyx mori (BM-5), Lymantria dispar (IPLB-LD-625Y), Trichoplusia ni (BTI-Tn-5B1-4), Anticarsia gemmatalis (UFL-AG-286), and S. frugiperda (IPLB-SF-21AE and Sf9) were tested for their susceptibility to a highly-virulent Brazilian isolate of SfMNPV. The cytopathic effects induced by the virus, the production of viral particles, and the synthesis of viral polypeptides were examined and compared. Both S. frugiperda cell lines showed hypertrophy of cell nuclei and production of many polyhedra. The SDS-Page of radiolabed proteins showed that the cell protein synthesis was shutoff, while an intense band of about 30 kDa, recognized as polyhedrin, was synthesized. The other cell lines did not show polyhedra production, although some of them underwent morphological changes and protein synthesis shutdown in response to virus infection. The SF-21 and Sf9 cell lines are recommended for further in vitro production of SfMNPV.

Abstract Mesosetum is a Neotropical genus with 25 species, and 21 of them occur in Brazil. Mesosetum forms a clade closely related with Keratochlaena rigidifolia and Tatianyx arnacites. The objective of this work was to establish the taxonomic value of the upper anthecium micromorphology for the group. A total of 96 specimens, representing all Mesosetum species (except M. wrightii), K. rigidifolia and T. arnacites were examined under a scanning electron microscope (SEM). PCA and UPGMA analysis were applied using the micromorphologicalcharacters. Fifithteen useful taxonomic characters were identified. We highlight the following characters to distinguish the Mesosetum species: the presence, type and distribution of papillae on the abaxial surface of the upper lemma; the presence of unicellular macrohairs and bicellular microhairs; presence or absence of silica cells and the structure of the germination lid. The present work shows that the micromorphological characters identified are important taxonomically at the specific level, allowing the species identification in many cases.

O objetivo deste trabalho foi investigar prováveis modos de ação da levedura Cryptococcus magnus, que resultam no controle da antracnose (Colletotrichum gloeosporioides) em frutos de mamoeiro na póscolheita. A microscopia eletrônica de varredura foi utilizada para avaliar o efeito da levedura sobre inoculações realizadas após a colheita. Os resultados mostraram que C. magnus é capaz de colonizar a superfície de ferimentos nos frutos e vencer a competição por espaço e, provavelmente, por nutrientes. Além disso, C. magnus produz uma matriz de textura característica que afeta a integridade da hifa do patógeno. A competição por espaço e a produção de substâncias que afetam a integridade das hifas estão entre os mais importantes modos de ação desta levedura.

The objective of this work was to investigate possible modes of action of the yeast Cryptococcus magnus in controlling anthracnose (Colletotrichum gloeosporioides) on post harvested papaya fruits. Scanning electron microscopy was used to analyze the effect of the yeast on inoculations done after harvest. Results showed that C. magnus is able to colonize wound surfaces much faster than the pathogen, outcompeting the later for space and probably for nutrients. In addition, C. magnus produces a flocculent matrix, which affects hyphae integrity. The competition for space and the production of substances that affect hyphae integrity are among the most important modes of action of this yeast.

O objetivo deste trabalho foi selecionar e caracterizar, no Banco de Germoplasma de Bacillus spp., da Empresa Brasileira de Pesquisa Agropecuária, as estirpes de Bacillus thuringiensis mais tóxicas à Plutella xylostella, por métodos morfológicos, bioquímicos e moleculares. Das 203 estirpes testadas, sete causaram 100% de mortalidade e foram semelhantes à estirpe padrão utilizada, B. thuringiensis subsp. kurstaki. Elas apresentaram proteínas de 130 kDa e 65 kDa, presença de genes cry1 e cry2 e cristais bipiramidais, cubóides e redondos. As estirpes selecionadas oferecem novas perspectivas de controle de P. xylostella.

The aim of this work was to select and characterize the most toxic Bacillus thuringiensis strains, from the Germplasm Bank of Bacillus spp. of Empresa Brasileira de Pesquisa Agropecuária, against Plutella xylostella. Strains were characterized by morphological, biochemical and molecular methods. It was observed that seven out of the 203 strains tested showed high toxicity compared to the standard used B. thuringiensis subsp. kurstaki (HD-1), which showed 100% mortality. Selected strains showed features described for lepidoptera regarding the protein of 130 kDa and 65 kDa; profile and features were obtained through the PCR reactions, making possible to identify the presence of cry1 and cry2 genes. Moreover, the scanning electron microscopy showed the bipiramydal, cubed and round crystal forms. The selected strains offer new perspectives to control P. xylostella.

Neste trabalho foram realizados testes de patogenicidade com 210 estirpes de Bacillus thuringiensis contra larvas de Aedes aegypti e Culex quinquefasciatus, a fim de se determinar as mais eficazes. Estas estirpes foram isoladas de diversas regiões do Brasil e estão armazenadas na coleção de Bacillus spp. da Embrapa Recursos Genéticos e Biotecnologia. As estirpes selecionadas foram caracterizadas por métodos morfológicos (microscopia), bioquímicos (SDS-PAGE 10%) e moleculares (Reação em Cadeia da Polimerase). Foram selecionadas seis estirpes entomopatogênicas de Bacillus thuringiensis. Nenhuma das estirpes de Bacillus thuringiensis apresentou produtos de PCR esperados para a detecção dos genes cry4, cry11 e cyt1A. A patogenicidade das estirpes não está associada à presença das toxinas Cry4, Cry11 ou Cyt, assim, essas estirpes poderão ser utilizadas para a formatação de um bioinseticida alternativo contra mosquitos.

The objective of this work was to evaluate 210 Bacillus thuringiensis strains against Aedes aegypti and Culex quinquefasciatus larvae to select the most effective. These strains were isolated from different regions of Brazil and are stored in a Bacillus spp. collection at Embrapa Recursos Genéticos e Biotecnologia, Brasília, Brazil. The selected strains were characterized by morphological (microscopy), biochemical (SDS-PAGE 10%) and molecular (PCR) methods. Six B. thuringiensis strains were identified as mosquito-toxic after the selective bioassays. None of the strains produced the expected PCR products for detection of cry4, cry11 and cyt1A genes. These results indicate that the activity of mosquitocidal Brazilian strains are not related with Cry4, Cry11 or Cyt proteins, so they could be used as an alternative bioinsecticide against mosquitoes.

O objetivo deste trabalho foi selecionar entre 300 estirpes de Bacillus thuringiensis as efetivas simultaneamente contra larvas de Spodoptera frugiperda J.E. Smith e Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), Anthonomus grandis Boheman (Coleoptera: Curculionidae), Aedes aegypti Linnaeus e Culex quinquefasciatus Say (Diptera: Culicidae). Foram selecionadas duas estirpes de B. thuringiensis, denominadas S234 e S997, que apresentaram atividade contra as três ordens de insetos. As estirpes foram caracterizadas por métodos morfológicos, bioquímicos e moleculares. As mesmas apresentaram duas proteínas principais de 130 e 65 kDa, produtos de reação em cadeia da polimerase de tamanho esperado para a detecção dos genes cry1Aa, cry1Ab, cry1Ac, cry1B e cry2 e cristais bipiramidais, cubóides e esféricos.

The aim of this work was to select among 300 strains of Bacillus thuringiensis those which are simultaneously effective against larvae of Spodoptera frugiperda J.E. Smith and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), Anthonomus grandis Boheman (Coleoptera: Curculionidae), Aedes aegypti Linnaeus and Culex quinquefasciatus Say (Diptera: Culicidae). Two strains of B. thuringiensis were selected, S234 and S997, which presented activity against those three insect orders. Both strains were characterized by morphological, biochemical and molecular methods. They have presented two main proteins with 130 and 65 kDa, polimerase chain reaction products with expected sizes for detection of the genes cry1Aa, cry1Ab, cry1Ac, cry1B and cry2 and bipiramidal, cubical and spherical crystals.