Os autores gostariam de agradecer aos membros anteriores do Banco de laboratório: Sam-Kyu Kim, Kathryn Plichta e Victoria Miranda-Thompson por suas contribuições para a melhoria de muitos destes protocolos. Agradecemos o apoio da National Science Foundation (subvenções IOS-0840932 e IOS-0724978) a SP estoque.

1. Coleta de Amostras de solo <ol><li> Considere que cobre uma área mínima de 2 - 4 m 2 para cada local de amostragem. </li><li> Recolha de amostras de solo a uma profundidade de pelo menos 15 cm (Figura 4). </li><li> Tome pelo menos 5 amostras aleatórias dentro desta área. </li><li> Tome 3 subamostras por amostra. Dependendo do objetivo do estudo, ou combinar as subamostras ou mantê-los separados. </li><li> Coloque cada amostra em um saco plástico. Considere duplo ensacamento para evitar vazamento de amostras (Figura 4). </li><li> Amostras de etiquetas com um marcador à prova d&#39;água. Inclua as seguintes informações de cada local de amostragem: informações do site (incluindo localidade / área / nome do site e GPS coordenar informações), data, habitat, a vegetação associada, temperatura, altitude, etc NOTA: Se for o caso, recolher e / ou registrar a presença de insetos e outros invertebrados coletados com a amostra para posterior identificação. Eles podem representar potencial naturhospedeiros al EPN. </li><li> Ferramentas de recolha limpos entre as amostras mediante a lavagem com água e / ou desinfectar as com etanol a 70% ou solução de lixívia a 0,5%. </li><li> Manter as amostras em um refrigerador (8 - 15 ° C) durante o transporte para o laboratório. </li><li> Pegue uma porção da amostra de solo para análise para obter informações sobre a composição do solo, textura, umidade, condutividade elétrica ou outros parâmetros do solo desejados. </li></ol> . 2 Isolamento Nematóides de amostras de solo: Técnica do Inseto-baiting <ol><li> Remova todos os detritos (ie., Rochas, pedaços de madeira ou casca, folhas, etc.), Coletados com suas amostras para evitar a contaminação com microorganismos saprobic. </li><li> Adicionar água para umedecer o solo e facilitar a circulação de nematóides. NOTA: Use um frasco de spray para aumentar lentamente o nível de umidade do solo. </li><li> Colocar aproximadamente 200 a 250 ml de solo húmido num recipiente de plástico limpo com uma tampa. </li><li> Adicionar iscas de insetos. Considere 5 a 10 insectos para a superfície do solo de cada amostra (Figura 5). </li><li> Cobrir o recipiente com tampa e ligar recipientes de cabeça para baixo. </li><li> Manter recipientes no escuro e à temperatura ambiente (normalmente 22-25 ° C). </li><li> Verifique os recipientes a cada 2 - 3 dias, e remover insetos mortos. NOTA: adicionar insetos saudáveis ​​adicionais para cada recipiente para posterior baiting da amostra de solo. </li><li> Remover insetos mortos dos recipientes. NOTA: Cadáveres com um marrom ou ocre coloração geralmente são parasitados por steinernematids, enquanto tijolo vermelho para cadáveres roxo escuro são parasitados por heterorhabditids. </li><li> Enxágüe cadáveres em água estéril. </li><li> Coloque cadáveres em uma armadilha Branco modificado para recuperação de nematóide progênie (ver procedimento abaixo). </li></ol> . 3 Nematode recuperação de cadáveres infectados: Modificado Armadilha Branco <ol><li> Coloque a parte superior de um diâmetro 50 (ou 60) mm. Placa de Petri dentro de um prato grande (100 mm). </li><li> Definir um pecadopapel de filtro circular gle (Whatman # 1) no interior do prato menor. </li><li> Coloque cadáveres sobre o papel de filtro do prato menor certificando-se de cadáveres não se tocam para evitar qualquer contaminação. </li><li> Encha o exterior (maior) placa de Petri com ca. 20 ml de água destilada estéril. Não adicionar água no prato que contém os cadáveres. </li><li> Cobrir a grande placa de Petri e seu conteúdo, com a tampa (Figura 6). </li><li> Rotular pratos de acordo. Adicione as seguintes informações: Nome do Nemátodo (espécie / isolado), a data de infecção (infecção data foi definida) e data armadilha (esta é a data em que a armadilha está configurado). </li><li> Mantenha a armadilha RT até a emergência dos estágios juvenis infectantes (IJS) ocorre. Este processo pode levar entre 10 - 25 dias, dependendo da espécie e / ou tensão considerado nematóides. </li><li> Colheita de água com IJs removendo o maior prato da armadilha e despejar água com nematóides para um copo. </li><li> Permitir nemátodos decantar para a parte inferior da bEaker. Este processo pode demorar alguns minutos. </li><li> Despeje água cuidadosamente, certificando-se de nematóides permanecem no fundo do copo. </li><li> Lavar nematóides, adicionando mais água e permitindo que os nemátodos para decantar. Este passo pode ser repetido 2-3 vezes, até que a água é limpa. </li><li> Colocar a suspensão de nemátodos num balão de cultura de tecidos (250 ml). Manter a concentração da suspensão a 1.000 - 3.000 nemátodos / ml. </li><li> Frasco loja com suspensão de nematóides em uma sala fria ou em estufa entre 10-20 ° C. NOTA: verifique frascos armazenados periodicamente como a vida de prateleira de EPN é variável. Normalmente steinernematids pode ser armazenado por 6-12 meses, sem a necessidade de subcultura, enquanto heterorhabditids pode exigir mais check-ups periódicos. </li></ol>

<ol>
	<li>Bedding, R. A., Akhurst, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+technique+for+the+detection+of+insect+parasitic+rhabditid+nematodes+in+soil.">A simple technique for the detection of insect parasitic rhabditid nematodes in soil.</a> Nematologica. 21, 109-110 (1975).</li><li>Boemare, N. E., Akhurst, R. A., Dworkin, M., Falkow, S., Rosenberg, E., Schleifer, K. -. H., Stackebrandt, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Genera Photorhabdus and Xenorhabdus. In The Prokaryotes. , 473-488 (2007).</li><li>Gaugler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Entomopathogenic Nematology. , (2002).</li><li>Gaugler, R., Kaya, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Entomopathogenic Nematode s in Biological Control. , (1990).</li><li>Hazir, S., Keskin, N., Stock, S. P., Kaya, H. K., &#214;zcan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diversity+and+distribution+of+entomopathogenic+nematodes+(Rhabditida:+Steinernematidae+and+Heterorhabditidae)+in+Turkey.">Diversity and distribution of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) in Turkey.</a> Biodiversit., &amp; Conservation. 12, 375-386 (2003).</li><li>Kaya, H. K., Gaugler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entomopathogenic+nematodes.">Entomopathogenic nematodes.</a> Annual Review of Entomology. 38, 181-206 (1993).</li><li>Kaya, H. K., Stock, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Techniques in insect nematology. In Manual of techniques in insect pathology. , 281-324 (1997).</li><li>Lacey, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manual of techniques in invertebrate pathology. , (2012).</li><li>McCoy, C. W., Shapiro-Ilan, D., Duncan, L., Nguyen, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entomopathogenic+nematodes+and+other+natural+enemies+as+mortality+factors+for+larvae+of+Diaprepes+abbreviatus+(Coleoptera:+Curculionidae).">Entomopathogenic nematodes and other natural enemies as mortality factors for larvae of Diaprepes abbreviatus (Coleoptera: Curculionidae).</a> Biological Control. 19, 182-190 (2000).</li><li>Meyling, N. V., Eilenberg, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Occurrence+and+distribution+of+soil+borne+entomopathogenic+fungi+within+a+single+organic+agroecosystem.">Occurrence and distribution of soil borne entomopathogenic fungi within a single organic agroecosystem.</a> Agriculture, ecosystem., &amp; environment. 113, 336-341 (2006).</li><li>Poinar, G. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Taxonomy and biology of Steinernematidae and Heterorhabditidae. In: Entomopathogenic Nemtaodes in Biological. , 23-61 (1990).</li><li>Stock, S. P., Gress, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diversity+and+phylogenetic+relationships+of+entomopathogenic+nematodes+(Steinernematidae+and+Heterorhabditidae)+from+the+Sky+Islands+of+southern+Arizona.">Diversity and phylogenetic relationships of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) from the Sky Islands of southern Arizona.</a> Journal of invertebrate pathology. 92, 66-72 (2006).</li><li>Stock, S. P., Hunt, D. J., Grewal, P. S., Ehlers, R. U., Shapiro-Ilan, D. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nematode+morphology+and+systematics.">Nematode morphology and systematics.</a> Nematodes as biological control agents. CAB International Publishing. , 3-43 (2005).</li><li>Stock, S. P., Goodrich&#8211;Blair, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entomopathogenic+nematodes+and+their+bacterial+symbionts:+The+inside+out+of+a+mutualistic+association.">Entomopathogenic nematodes and their bacterial symbionts: The inside out of a mutualistic association.</a> Symbiosis. 46, 65-75 (2008).</li><li>Stuart, R. J., Gaugler, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patchiness+in+populations+of+entomopathogenic+nematodes.">Patchiness in populations of entomopathogenic nematodes.</a> Journal of Invertebrate Pathology. 64, 39-45 (1994).</li><li>White, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+obtaining+infective+nematode+larvae+from+cultures.">A method for obtaining infective nematode larvae from cultures.</a> Science. 66, 302-303 (1927).</li></ol>

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Esta demonstração é a primeira de duas apresentações que descrevem um número de técnicas que são comummente usados ​​para estudar EPN e suas bactérias simbióticas. Estas técnicas representam passos fundamentais para o sucesso da criação culturas EPN em laboratório e também servir de base para outros bioensaios que empregam EPN como organismos modelo para a pesquisa. Vários levantamentos de solos de EPN têm mostrado que a sua abundância e distribuição pode variar entre...

Muitos nematóides estão associados com insetos, e suas interações hospedeiro variam de benéfico para prejudicial. Aqui, vamos nos concentrar em um grupo de nematóides que são patógenos de insetos, também conhecido como nematóides entomopatogênicos (ou EPN). Duas famílias de nematóides pertencem a este grupo de nematóides: Steinernematidae e Heterorhabditidae 11,13. O seu efeito patogênico é de fato conferida pela sua interação com anaeróbios facultativos bactérias entéricas (bactérias Xenorhabdus associar steinernematids e bactérias Photorhabdus associar heterorhabditids) 2. As bactérias são vetorizado de um hospedeiro a outro por insetos a única fase livre nematóide de vida, a terceira fase juvenil infecciosa (também conhecida como juvenil Dauer, juvenil infecciosa ou IJ), que vive no solo. Uma vez dentro do inseto, os nematóides liberar as bactérias na hemolinfa do inseto, que matam o inseto hospedeiro por septicemia maciça. As bactérias tambémdegradam os tecidos do insecto e se tornar fonte de alimento dos nematóides, permitindo-lhes a amadurecer e multiplicar. Normalmente, uma ou duas gerações de nematóides adultos são produzidos dentro do cadáver do inseto. A progênie dos últimos reassociates geração de adultos com algumas células bacterianas em um mais especializar maneira que sua relação nutricional anterior e cultivar essas células em seus intestinos que se deslocam para fora do inseto carcaça no solo onde irão aguardar outro inseto parasitar 6,11,14 (Figura 1). Desde sua descoberta em 1927, EPN foram consideradas alternativas valiosas para pesticidas químicos como eles podem parasitar uma grande variedade de insetos que são pragas agrícolas 3,4,5. No entanto, ao longo das últimas duas décadas, esses nematóides e suas bactérias simbióticas ter sido reconhecido como um sistema modelo para o estudo de aspectos maleável biológicos, ecológicos e evolutivos de host-micróbio interactions 14. O objetivo desta apresentação é mostrar os métodos e técnicas mais comumente utilizadas para a amostragem do solo e isolamento de EPN. Uma variedade de ferramentas está disponível e pode ser usado para a coleta de amostras de solo, incluindo: corers solo, espátulas, escavadoras pós-buracos, brocas, tubos de amostragem, pás de mão, entre outros (Figura 2). Dependendo do objectivo do estudo, duas estratégias de amostragem pode ser considerada: a) estratificado, b) amostragem (Figura 3). A amostragem estratificada é normalmente usado como parte de um estudo intensivo de uma área específica ou demarcada sobre um dado período de tempo. Em geral, uma seção transversal é demarcado e amostras de solo são tomadas a intervalos previstos na transecção ao longo de um período de tempo (Figura 3A) 15. A amostragem aleatória é geralmente empregada quando o foco em uma área extensa. Esta estratégia de amostragem foi usado para estudar a diversidade de EPN fesde uma grande área geográfica ou região (Figura 3B) 12. Uma série de fatores podem ser considerados, dependendo do foco do estudo, incluindo uma grande variedade de elevações, texturas de solo e habitats (por exemplo., Campos cultivados, florestas, pastos, parques, praias, matas ciliares, etc.) Mostramos a técnica de atracção de insectos, que foi originalmente descrito por Bedding e Akhurst 1 e representa uma alternativa simples e selectiva para a recuperação a partir de amostras de solo de EPN. Este é um processo selectiva que é baseado na premissa de que os nemátodos (estádio IJ) será atraído para uma série de insectos e que parasitam. Esta técnica também pode ser considerada para o isolamento de outros agentes patogénicos de insectos, tais como fungos, bactérias e 8,10. Também demonstramos a técnica armadilha branco modificado que é utilizado para a recuperação de nemátodo progenitura de hospedeiros infectados insectos 7,14. Este é um esforço method que oferece a vantagem de recuperar uma &quot;limpa&quot; nematóide progênie livre de restos de cadáveres de insetos degradantes. Finalmente, as técnicas descritas e mostradas neste artigo correspondem aos concebido e / ou realizados no nosso laboratório, bem como os descritos por vários colegas e colaboradores.

<table><tbody><tr><td>&lt;em&gt;Galleria mellonella&lt;/em&gt;</td><td>Timberline</td><td>http://www.timberlinefisheries.com/ProductDetails.asp?ProductCode=WAXLG</td><td>For insect baiting technique</td></tr><tr><td>Filter paper, 55 mm Grade 1 Cellulose</td><td>Whatman/VWR</td><td>28450-048</td><td>Infection chamber and White trap assembly</td></tr><tr><td>60 x 15 mm Petri dishes</td><td>VWR</td><td>25384-092</td><td>Infection chamber and White trap assembly</td></tr><tr><td>100 x 15 mm Petri dishes</td><td>VWR</td><td>25384-088</td><td>Infection chamber and White trap assembly</td></tr><tr><td>ZIPloc plastic bags</td><td>Ace Hardware or local hardware store</td><td></td><td>Soil sampling</td></tr><tr><td>Mechanical pipettor P1000, P200 ml</td><td>VWR</td><td>89130-562; 89130-566&amp;nbsp;</td><td>Infection chamber and White trap assembly</td></tr><tr><td>Pippetor tips 1000ml, 200 ml</td><td>VWR</td><td>16466-004 ; 53510</td><td>Infection chamber and White trap assembly</td></tr><tr><td>Bleach</td><td>Ace Hardware or local hardware store</td><td></td><td>Soil sampling , disinfecting</td></tr><tr><td>Sodium hypochlorite</td><td>Ace Hardware or local hardware store</td><td></td><td>Soil sampling , disinfecting</td></tr><tr><td>70% Ethyl alochol</td><td>AAPER</td><td>17212945</td><td>Soil sampling , disinfecting</td></tr><tr><td>Shovels</td><td>Ace Hardware or local hardware store</td><td>N/A</td><td>Soil sampling</td></tr><tr><td>Tubular soil sampler</td><td>Accuproducts</td><td></td><td>Soil sampling</td></tr><tr><td>Soil probe, long handle</td><td>Nupla&amp;nbsp;</td><td>PRB4T 69401 Classic</td><td>Soil sampling</td></tr><tr><td>Measuring tape</td><td>Ace Hardware or local hardware store</td><td></td><td>Soil sampling</td></tr><tr><td>Flagging tape, various colors</td><td>Ace Hardware or local hardware store</td><td></td><td>Soil sampling</td></tr><tr><td>Tissue culture flasks</td><td>VWR</td><td>Falcon, 29185-304&amp;nbsp;</td><td>White trap, collection of EPN</td></tr><tr><td>Wash bottles, polyethylene, wide mouth</td><td>VWR</td><td>16650-107</td><td>White trap, collection of EPN</td></tr></tbody></table>

soil sampling and isolation of entomopathogenic nematodes (steinernematidae, heterorhabditidae)

Nematóides entomopatogênicos (aka EPN) representam um grupo de nematóides que vivem no solo que parasitam uma grande variedade de insetos. Esses nematóides pertencem a duas famílias: Steinernematidae e Heterorhabditidae. Até agora, mais de 70 espécies já foram descritas no Steinernematidae e existem cerca de 20 espécies no Heterorhabditidae. Os nematóides têm uma parceria de mutualismo com bactérias Enterobacteriaceae e, juntos, eles agem como um complexo potente inseticida que mata uma grande variedade de espécies de insetos. Aqui, vamos nos concentrar nas técnicas mais comuns considerados para a recolha de EPN do solo. A segunda parte desta apresentação centra-se na técnica de atracção de insectos, uma abordagem amplamente utilizada para o isolamento de EPN de amostras de solo, e a técnica de armadilha branco modificado, que é utilizado para a recuperação destes nematóides de insectos infectadas. Estes métodos e técnicas são passos fundamentais para o sucesso da criação EPN cultUres em laboratório e também servir de base para outros bioensaios que consideram estes nematóides como organismos modelo para a pesquisa em outras disciplinas biológicas. As técnicas indicadas nesta apresentação correspondem às realizadas e / ou concebida por membros da SP laboratório, bem como os descritos por vários autores.

Coleta de Amostras de solo Em estágio Terceiro juvenis infectantes de EPN são os únicos estágios gratuitos de vida no ciclo de vida desses nematóides que residem no solo (Figura 1). Portanto, a recolha de amostras de solo é um método muito eficiente para recuperar estes nemátodos. Figura 4 mostra um perfil de solo que indica a profundidade a que devem ser recolhidas amostras. Preservar a umidade de uma amostra é um fator chave para a sobrevivência ...

Watch this Scientific Journal Video about Soil Sampling and Isolation of Entomopathogenic Nematodes Steinernematidae, Heterorhabditidae at JoVE.com

Soil Sampling and Isolation of Entomopathogenic Nematodes Steinernematidae, Heterorhabditidae

Nematóides entomopatogênicos são vermes que vivem no solo que parasitam uma grande variedade de insetos. Demonstramos métodos de amostragem utilizados para o isolamento destes nematóides do solo utilizando duas técnicas: a iscagem inseto ea armadilha Branco modificado, para a recuperação de nematóides de amostras de solo e cadáveres de insetos infectados, respectivamente.

Amostragem do solo e isolamento de nematóides entomopatogênicos (Steinernematidae, Heterorhabditidae)

Entomopathogenic nematodes (a.k.a. EPN) represent a group of soil-inhabiting nematodes that parasitize a wide range of insects. These nematodes belong to ...

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Environment

Soil Sampling and Isolation of Entomopathogenic Nematodes (Steinernematidae, Heterorhabditidae)

24.9K visualizações.  University of Arizona.  Nematóides entomopatogênicos são vermes que vivem no solo que parasitam uma grande variedade de insetos. Demonstramos métodos de amostragem utilizados para o isolamento destes nematóides do solo utilizando duas técnicas: a iscagem inseto ea armadilha Branco modificado, para a recuperação de nematóides de amostras de solo e cadáveres de insetos infectados, respectivamente. 

Vídeo: Soil Sampling and Isolation of Entomopathogenic Nematodes Steinernematidae, Heterorhabditidae

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes and soil organic matter formation to small-scale stable-isotope biomarker probing. Coupling multiple stable isotopes such as 13C with 15N, 18O or&#160;2H has the potential to reveal even more information about complex stoichiometric relationships during biogeochemical transformations. Isotope labeled plant material has been used in various studies of litter decomposition and soil organic matter formation1-4. From these and other studies, however, it has become apparent that structural components of plant material behave differently than metabolic components (i.e. leachable low molecular weight compounds) in terms of microbial utilization and long-term carbon storage5-7. The ability to study structural and metabolic components separately provides a powerful new tool for advancing the forefront of ecosystem biogeochemical studies. Here we describe a method for producing 13C and 15N labeled plant material that is either uniformly labeled throughout the plant or differentially labeled in structural and metabolic plant components.
Here, we present the construction and operation of a continuous 13C and 15N labeling chamber that can be modified to meet various research needs. Uniformly labeled plant material is produced by continuous labeling from seedling to harvest, while differential labeling is achieved by removing the growing plants from the chamber weeks prior to harvest. Representative results from growing Andropogon gerardii Kaw demonstrate the system&#39;s ability to efficiently label plant material at the targeted levels. Through this method we have produced plant material with a 4.4 atom%13C and 6.7 atom%15N uniform plant label, or material that is differentially labeled by up to 1.29 atom%13C and 0.56 atom%15N in its metabolic and structural components (hot water extractable and hot water residual components, respectively). Challenges lie in maintaining proper temperature, humidity, CO2 concentration,&#160;and light levels in an airtight 13C-CO2 atmosphere for successful plant production. This chamber description represents a useful research tool to effectively produce uniformly or differentially multi-isotope labeled plant material for use in experiments on ecosystem biogeochemical cycling.

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

This method explains how to build and operate a continuous 13C and 15N isotope labeling chamber for uniform or differential plant tissue labeling. Representative results from metabolic and structural labeling of Andropogon gerardii are discussed.

Projeto e operação de uma contínua<sup&gt; 13</sup&gt; C e<sup&gt; 15</sup&gt; N Labeling Câmara de uniforme ou Diferencial, metabólica e estrutural, Fábrica de Marcação por Isótopo

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes ...

Ambiente

Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals is often not well understood. Here we demonstrate an integrated field lysimetry and porewater sampling method for evaluating the mobility of chemicals applied to soils and established vegetation. Lysimeters, open columns made of metal or plastic, are driven into bareground or vegetated soils. Porewater samplers, which are commercially available and use vacuum to collect percolating soil water, are installed at predetermined depths within the lysimeters. At prearranged times following chemical application to experimental plots, porewater is collected, and lysimeters, containing soil and vegetation, are exhumed. By analyzing chemical concentrations in the lysimeter soil, vegetation, and porewater, downward leaching rates, soil retention capacities, and plant uptake for the chemical of interest may be quantified. Because field lysimetry and porewater sampling are conducted under natural environmental conditions and with minimal soil disturbance, derived results project real-case scenarios and provide valuable information for chemical management. As chemicals are increasingly applied to land worldwide, the described techniques may be utilized to determine whether applied chemicals pose adverse effects to human health or the environment.

Field lysimetry and porewater sampling allow researchers to evaluate the fate of chemicals applied to soils and established vegetation. The goal of this protocol is to demonstrate how to install required instrumentation and collect samples for chemical analysis during integrated field lysimetry and porewater sampling experiments.

Integrado Campo Lysimetry e Porewater Amostragem para Avaliação de Química Mobilidade em Solos e Vegetação Fundada

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals ...

Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance

A major concern when developing commercial mycoinsecticides is the kill speed compared to that of chemical insecticides. Therefore, isolation and screening for the selection of a fast-acting, highly virulent entomopathogenic fungus are important steps. Entomopathogenic fungi, such as Metarhizium, Beauveria, and Nomurea, which act by contact, are better suited than Bacillus thuringiensis or nucleopolyhedrosis virus (NPV), which must be ingested by the insect pest. In the present work, we isolated 68 Metarhizium strains from infected insects using a soil dilution and bait method. The isolates were identified by the amplification and sequencing of the ITS1-5.8S-ITS2 and 26S rDNA region. The most virulent strain of Metarhizium anisopliae was selected based on the median lethal concentration (LC50) and time (LT50) obtained in insect bioassays against III-instar larvae of Helicoverpa armigera. The mass production of spores by the selected strain was carried out with solid-state fermentation (SSF) using rice as a substrate for 14 days. Spores were extracted from the sporulated biomass using 0.1% tween-80, and different formulations of the spores were prepared. Field trials of the formulations for the control of an H. armigera infestation in pigeon peas were carried out by randomized block design. The infestation control levels obtained with oil and aqueous formulations (78.0% and 70.9%, respectively) were better than the 63.4% obtained with chemical pesticide.

Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance

Here, we report the different stages involved in the knowledge-based development of an effective mycoinsecticide, including the isolation, identification, screening, and selection of the "best-fit" entomopathogenic fungus, Metarhizium anisopliae, for the control of insect pests in agriculture.

Desenvolvimento de<em&gt; Metarhizium anisopliae</em&gt; Como um Mycoinsecticide: do isolamento ao desempenho do campo

A major concern when developing commercial mycoinsecticides is the kill speed compared to that of chemical insecticides. Therefore, isolation and ...

In vivo and In vitro Rearing of Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae)

Entomopathogenic nematodes (EPN) (Steinernematidae and Heterorhabditidae) have a mutualistic partnership with Gram-negative Gamma-Proteobacteria in the family Enterobacteriaceae. Xenorhabdus bacteria are associated with steinernematids nematodes while Photorhabdus are symbionts of heterorhabditids. Together nematodes and bacteria form a potent insecticidal complex that kills a wide range of insect species in an intimate and specific partnership. Herein, we demonstrate in vivo and in vitro techniques commonly used in the rearing of these nematodes under laboratory conditions. Furthermore, these techniques represent key steps for the successful establishment of EPN cultures and also form the basis for other bioassays that utilize these organisms for research. The production of aposymbiotic (symbiont&#8211;free) nematodes is often critical for an in-depth and multifaceted approach to the study of symbiosis. This protocol does not require the addition of antibiotics and can be accomplished in a short amount of time with standard laboratory equipment. Nematodes produced in this manner are relatively robust, although their survivorship in storage may vary depending on the species used. The techniques detailed in this presentation correspond to those described by various authors and refined by P. Stock&#8217;s Laboratory, University of Arizona (Tucson, AZ, USA). These techniques are distinct from the body of techniques that are used in the mass production of these organisms for pest management purposes.

In vivo and In vitro Rearing of Entomopathogenic Nematodes Steinernematidae and Heterorhabditidae

The goal of this presentation is to demonstrate in vivo and in vitro techniques for the rearing of entomopathogenic nematodes. In vivo methods consider the rearing of these nematodes with an insect host, whereas the in vitro methods utilize rich agar media.

In vivo e in vitro criação de Nematóides entomopatogênicos (Steinernematidae e Heterorhabditidae)

Entomopathogenic nematodes (EPN) (Steinernematidae and Heterorhabditidae) have a mutualistic partnership with Gram-negative Gamma-Proteobacteria in the ...

Bioengenharia

Rapid Isolation of Wild Nematodes by Baermann Funnel

Beyond being robust experimental model organisms, Caenorhabditis elegans and its relatives are also real animals that live in nature. Studies of wild nematodes in their natural environments are valuable for understanding many aspects of biology, including the selective regimes in which distinctive genomic and phenotypic characters evolve, the genetic basis for complex trait variation, and the natural genetic diversity fundamental to all animal populations. This manuscript describes a simple and efficient method for extracting nematodes from their natural substrates, including rotting fruits, flowers, fungi, leaf litter, and soil. The Baermann funnel method, a classical nematology technique, selectively isolates active nematodes from their substrates. Because it recovers nearly all active worms from the sample, the Baermann funnel technique allows for the recovery of rare and slow-growing genotypes that co-occur with abundant and fast-growing genotypes, which might be missed in extraction methods that involve multiple generations of reproduction. The technique is also well suited to addressing metagenetic, population-genetic, and ecological questions. It captures the entire population in a sample simultaneously, allowing an unbiased view of the natural distribution of ages, sexes, and genotypes. The protocol allows for deployment at scale in the field, rapidly converting substrates into worm plates, and the authors have validated it through fieldwork on multiple continents.

This protocol outlines a method for efficiently extracting live nematodes from natural substrates in the field.

Isolamento Rápido de Nematoides Selvagens por Baermann Funnel

Beyond being robust experimental model organisms, Caenorhabditis elegans and its relatives are also real animals that live in nature. Studies of wild ...

Genética

Culturing and Genetically Manipulating Entomopathogenic Nematodes

Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects that live in the soil. The main characteristic of their life cycle is the mutualistic association with the bacteria Photorhabdus and Xenorhabdus, respectively. The nematode parasites are able to locate and enter suitable insect hosts, subvert the insect immune response, and multiply efficiently to produce the next generation that will actively hunt new insect prey to infect. Due to the properties of their life cycle, entomopathogenic nematodes are popular biological control agents, which are used in combination with insecticides to control destructive agricultural insect pests. Simultaneously, these parasitic nematodes represent a research tool to analyze nematode pathogenicity and host anti-nematode responses. This research is aided by the recent development of genetic techniques and transcriptomic approaches for understanding the role of nematode secreted molecules during infection. Here, a detailed protocol on maintaining entomopathogenic nematodes and using a gene knockdown procedure is provided. These methodologies further promote the functional characterization of entomopathogenic nematode infection factors.

Entomopathogenic nematodes live in symbiosis with bacteria and together they successfully infect insects by undermining their innate immune system. To promote research on the genetic basis of nematode infection, methods for maintaining and genetically manipulating entomopathogenic nematodes are described.

Culturing e Geneticamente Manipulação Nematodes Entomopatômicos

Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects that live in the soil. The main characteristic ...

Imunologia e Infecção

Isolation and Selection of Entomopathogenic Fungi from Soil Samples and Evaluation of Fungal Virulence against Insect Pests

Entomopathogenic fungi (EPF) are one of the microbial control agents for integrated pest management. To control local or invasive pests, it is important to isolate and select indigenous EPF. Therefore, the soil bait method combined with the insect bait (mealworm, Tenebrio molitor) system was used in this study with some modifications. The isolated EPF were then subjected to the virulence test against the agricultural pest Spodoptera litura. Furthermore, the potential EPF strains were subjected to morphological and molecular identifications. In addition, the conidia production and thermotolerance assay were performed for the promising EPF strains and compared; these data were further substituted into the formula of effective conidia number (ECN) for laboratory ranking. The soil bait-mealworm system and the ECN formula can be improved by replacing insect species and integrating more stress factors for the evaluation of commercialization and field application. This protocol provides a quick and efficient approach for EPF selection and will improve the research on biological control agents.

Here we present a protocol based on the&#160;mealworm (Tenebrio molitor)-bait system that was used for isolating and selecting entomopathogenic fungi (EPF) from soil samples. An effective conidia number (ECN) formula is used to select high stress tolerant EPF based on physiological characteristics for pest microbial control in the field.

Isolamento e Seleção de Fungos Entomopatômicos de Amostras de Solo e Avaliação da Virulência Fúngica contra Pragas de Insetos

Entomopathogenic fungi (EPF) are one of the microbial control agents for integrated pest management. To control local or invasive pests, it is important ...

Biologia

Comparison of Methods for Isolating Entomopathogenic Fungi from Soil Samples

The goal of the present study is to compare the effectiveness of using insect baits versus artificial selective medium for isolating entomopathogenic fungi (EPF) from soil samples. The soil is a rich habitat for microorganisms, including EPF particularly belonging to the genera Metarhizium and Beauveria, which can regulate arthropod pests. Biological products based on fungi are available in the market mainly for agricultural arthropod pest control. Nevertheless, despite the high endemic biodiversity, only a few strains are used in commercial bioproducts worldwide. In the present study, 524 soil samples were cultured on potato dextrose agar enriched with yeast extract supplemented with chloramphenicol, thiabendazole, and cycloheximide (CTC medium). The growth of fungal colonies was observed for 3 weeks. All Metarhizium and Beauveria EPF were morphologically identified at the genus level. Additionally, some isolates were molecularly identified at the species level. Twenty-four out of these 524 soil samples were also surveyed for EPF occurrence using the insect bait method (Galleria mellonella and Tenebrio molitor). A total of 51 EPF strains were isolated (41 Metarhizium spp. and 10 Beauveria spp.) from the 524 soil samples. All fungal strains were isolated either from croplands or grasslands. Of the 24 samples selected for comparison, 91.7% were positive for EPF using Galleria bait, 62.5% using Tenebrio bait, and 41.7% using CTC. Our results suggested that using insect baits to isolate the EPF from the soil is more efficient than using the CTC medium. The comparison of isolation methods in addition to the identification and conservation of EPF has a positive impact on the knowledge about biodiversity. The improvement of EPF collection supports scientific development and technological innovation.

Entomopathogenic fungal colonies are isolated from tropical soil samples using Tenebrio bait, Galleria bait, as well as selective artificial medium, i.e., potato dextrose agar enriched with yeast extract supplemented with chloramphenicol, thiabendazole, and cycloheximide (CTC medium).

Comparação de métodos para isolar fungos entomopatômicos de amostras de solo

The goal of the present study is to compare the effectiveness of using insect baits versus artificial selective medium for isolating entomopathogenic ...

A Highly Scalable Approach to Perform Ecological Surveys of Selfing Caenorhabditis Nematodes

Caenorhabditis elegans is one of the major model organisms in biology, but only recently have researchers focused on its natural ecology. The relative sparsity of information about C. elegans in its natural context comes from the challenges involved in the identification of the small nematode in nature. Despite these challenges, an increasing focus on the ecology of C. elegans has caused a wealth of new information regarding its life outside of the laboratory. The intensified search for C. elegans in nature has contributed to the discovery of many new Caenorhabditis species and revealed that congeneric nematodes frequently cohabitate in the wild, where they feed on microbial blooms associated with rotting plant material. The identification of new species has also revealed that the androdioecious mating system of males and self-fertilizing hermaphrodites has evolved three times independently within Caenorhabditis. The other two selfing species, C. briggsae and C. tropicalis, share the experimental advantages of C. elegans and have enabled comparative studies into the mechanistic basis of important traits, including self-fertilization. Despite these advances, much remains to be learned about the ecology and natural diversity of these important species. For example, we still lack functional information for many of their genes, which might only be attained through an understanding of their natural ecology. To facilitate ecological research of selfing Caenorhabditis nematodes, we developed a highly scalable method to collect nematodes from the wild. Our method makes use of mobile data collection platforms, cloud-based databases, and the R software environment to enhance researchers&#39; ability to collect nematodes from the wild, record associated ecological data, and identify wild nematodes using molecular barcodes.

A Highly Scalable Approach to Perform Ecological Surveys of Selfing Caenorhabditis Nematodes

This protocol can be used to perform large-scale ecological surveys of selfing Caenorhabditis nematodes. The primary advantage of this method is the efficient organization and analysis of ecological and molecular data associated with the nematodes collected from nature.

Uma abordagem altamente escalável para realizar pesquisas ecológicas de nematodes de caenorhabditis

Caenorhabditis elegans is one of the major model organisms in biology, but only recently have researchers focused on its natural ecology. The relative ...

Isolation and Characterization of the Natural Microbiota of the Model Nematode Caenorhabditis elegans

The nematode Caenorhabditis elegans interacts with a large diversity of microorganisms in nature. In general, C. elegans is commonly found in rotten plant matter, especially rotten fruits like apples or on compost heaps. It is also associated with certain invertebrate hosts such as slugs and woodlice. These habitats are rich in microbes, which serve as food for C. elegans and which can also persistently colonize the nematode gut. To date, the exact diversity and consistency of the native C. elegans microbiota across habitats and geographic locations is not fully understood. Here, we describe a suitable approach for isolating C. elegans from nature and characterizing the microbiota of worms. Nematodes can be easily isolated from compost material, rotting apples, slugs, or attracted by placing apples on compost heaps. The prime time for finding C. elegans in the Northern Hemisphere is from September until November. Worms can be washed out of collected substrate material by immersing the substrate in buffer solution, followed by the collection of nematodes and their transfer onto nematode growth medium or PCR buffer for subsequent analysis. We further illustrate how the samples can be used to isolate and purify the worm-associated microorganisms and to process worms for 16S ribosomal RNA analysis of microbiota community composition. Overall, the described methods may stimulate new research on the characterization of the C. elegans microbiota across habitats and geographic locations, thereby helping to obtain a comprehensive understanding of the diversity and stability of the nematode's microbiota as a basis for future functional research.

Isolation and Characterization of the Natural Microbiota of the Model Nematode Caenorhabditis elegans

Caenorhabditis elegans is one of the main model species in biology, yet almost all research is performed in the absence of its naturally associated microbes. The methods described here will help to improve our understanding of the diversity of associated microbes as a basis for future functional C. elegans research.

Isolamento e Caracterização da Microbiota Natural do Nematoide Modelo Caenorhabditis elegans

The nematode Caenorhabditis elegans interacts with a large diversity of microorganisms in nature. In general, C. elegans is commonly found in rotten plant ...

Amostragem do solo e isolamento de nematóides entomopatogênicos (Steinernematidae, Heterorhabditidae)

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