13 results on '"Stout, Michael Joseph"'
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2. Induced Jasmonate Signaling Leads to Contrasting Effects on Root Damage and Herbivore Performance
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Lu, Jing, Robert, Christelle Aurélie Maud, Riemann, Michael, Cosme, Marco, Mène-Saffrané, Laurent, Massana, Josep, Stout, Michael Joseph, Lou, Yonggen, Gershenzon, Jonathan, and Erb, Matthias
- Published
- 2015
3. Protocol for assessing soybean antibiosis to Chloridea virescens.
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Boiça Júnior, Arlindo Leal, Eduardo, Wellington Ivo, de Souza, Bruno Henrique Sardinha, de Moraes, Renato Franco Oliveira, Louvandini, Helder, Barbosa, José Carlos, and Stout, Michael Joseph
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SOYBEAN ,ANTIBIOSIS ,TOBACCO budworm ,INTEGRATED pest control ,SOYBEAN as feed ,LARVAE - Abstract
There are no standard protocols for assessing antibiosis in soybean, Glycine max (L.) (Fabaceae), cultivars to lepidopterans, including tobacco budworm, Chloridea virescens (Fabricius) (Lepidoptera: Noctuidae), an important species that causes damage to soybean crops in several production regions. This study was conducted to assess methodologies to determine the optimal combination of larval density, confinement container size, and plant structure in soybean antibiosis assays to C. virescens. In addition, primary and secondary metabolites in plant structures were analyzed to elucidate potential chemical resistance mechanisms against this lepidopteran. Antibiosis assays to C. virescens in resistant (IAC‐100) and susceptible (BR‐16) soybean cultivars were performed using three larval densities (one, two, and three larvae), two confinement container sizes (150 and 300 ml), and combinations of soybean plant structures (leaves, uncut pods, leaves + uncut pods, cut pods, and leaves + cut pods). Phenol, tannin, fiber, and lignin contents were quantified in the leaves, uncut pods, and grains of the soybean cultivars and related to biological development of C. virescens. Resistance levels in soybean cultivars in antibiosis assays were best differentiated using one larva per 150‐ml confinement container, fed only on soybean leaves. Higher contents of condensed tannins in the leaves of IAC‐100 cultivar may be one of the main chemical mechanisms of resistance to C. virescens. Our study is the first to determine the optimal combination of larval density, confinement container size, and plant structure for antibiosis assays in soybean cultivars to C. virescens. The developed protocol will benefit high‐throughput phenotyping in genetic breeding programs to obtain cultivars resistant to lepidopterans for use in integrated pest management. [ABSTRACT FROM AUTHOR]
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- 2022
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4. Comparative Efficacies of Next-Generation Insecticides Against Yellow Stem Borer and Their Effects on Natural Enemies in Rice Ecosystem
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Rahaman, Muhammad Matiar, primary and Stout, Michael Joseph, additional
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- 2019
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5. A fungal endophyte helps plants to tolerate root herbivory through changes in gibberellin and jasmonate signaling
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Cosme, Marco, primary, Lu, Jing, additional, Erb, Matthias, additional, Stout, Michael Joseph, additional, Franken, Philipp, additional, and Wurst, Susanne, additional
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- 2016
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6. Advances in the management of insect pests in rice
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Stout, Michael Joseph, primary
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- 2016
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7. Effect of plant compounds on induced activities of defense-related enzymes and pathogenesis related protein in bacterial blight disease susceptible rice plant
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Nisha, Selvamathiazhagan, primary, Revathi, Kannan, additional, Chandrasekaran, Rajamanickam, additional, Kirubakaran, Suyambulingam Arunachalam, additional, Sathish-Narayanan, Subbiah, additional, Stout, Michael Joseph, additional, and Senthil-Nathan, Sengottayan, additional
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- 2012
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8. Induced Jasmonate Signaling Leads to Contrasting Effects on Root Damage and Herbivore Performance.
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Jing Lu, Maud Robert, Christelle Aurélie, Riemann, Michael, Cosme, Marco, Mène-Saffrané, Laurent, Massana, Josep, Stout, Michael Joseph, Yonggen Lou, Gershenzon, Jonathan, and Erb, Matthias
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JASMONATE ,PLANT roots ,PLANT defenses ,HERBIVORES ,OXYLIPINS ,PLANT hormones - Abstract
Induced defenses play a key role in plant resistance against leaf feeders. However, very little is known about the signals that are involved in defending plants against root feeders and how they are influenced by abiotic factors. We investigated these aspects for the interaction between rice (Oryza sativa) and two root-feeding insects: the generalist cucumber beetle (Diabrotica balteata) and the more specialized rice water weevil (Lissorhoptrus oryzophilus). Rice plants responded to root attack by increasing the production of jasmonic acid (JA) and abscisic acid, whereas in contrast to in herbivore-attacked leaves, salicylic acid and ethylene levels remained unchanged. The JA response was decoupled from flooding and remained constant over different soil moisture levels. Exogenous application of methyl JA to the roots markedly decreased the performance of both root herbivores, whereas abscisic acid and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid did not have any effect. JA-deficient antisense 13-lipoxygenase (asLOX) and mutant allene oxide cyclase hebiba plants lost more root biomass under attack from both root herbivores. Surprisingly, herbivore weight gain was decreased markedly in asLOX but not hebiba mutant plants, despite the higher root biomass removal. This effect was correlated with a herbivore-induced reduction of sucrose pools in asLOX roots. Taken together, our experiments show that jasmonates are induced signals that protect rice roots from herbivores under varying abiotic conditions and that boosting jasmonate responses can strongly enhance rice resistance against root pests. Furthermore, we show that a rice 13-lipoxygenase regulates root primary metabolites and specifically improves root herbivore growth. [ABSTRACT FROM AUTHOR]
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- 2015
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9. Factors Influencing Expression of Antixenosis in Soybean to Anticarsia gemmatalis and Spodoptera frugiperda (Lepidoptera: Noctuidae).
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Boiça Júnior, Arlindo Leal, Souza, Bruno Henrique Sardinha De, Costa, Eduardo Neves, Ribeiro, Zulene Antonio, and Stout, Michael Joseph
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ARMYWORMS ,PLANT parasites ,HOST plants ,PLANT-pathogen relationships ,VELVET-bean caterpillar - Abstract
This study aimed to evaluate some factors that influence the expression of antixenosis in soybean genotypes against Anticarsia gemmatalis Hübner and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Free-choice and no-choice feeding assays were performed with the resistant soybean genotype IAC 100 and the susceptible genotype BRSGO 8360 using A. gemmatalis and S. frugiperda larvae. The following factors that may affect expression of resistance were evaluated: one larva versus two larvae per leaf disc; use of larvae without prior feeding suspension versus larvae starved for 3 h prior to the assay; leaf discs versus entire leaflets; upper part versus lower part of the plant; and, vegetative versus reproductive growth stages. The level of resistance exhibited by the genotype IAC 100 was high enough to not be obscured by the effects of all factors assayed in the present study upon the feeding preference of A. gemmatalis and S. frugiperda larvae. However, our results demonstrate the importance of knowing the optimal conditions for conducting an assay for evaluating resistance of genotypes for specialist and generalist insect species. Utilization of two larvae of A. gemmatalis per leaf disc, not starved before the assays, with leaf discs from the upper part of plants at the reproductive growth stage provided better discrimination of differences in antixenosis expression in soybean genotypes. For S. frugiperda, use of one larva per leaf disc, not starved before the assays, with leaf discs from the lower part of plants at the reproductive growth stage gave more satisfactory results for feeding preference tests. [ABSTRACT FROM PUBLISHER]
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- 2015
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10. Factors Influencing Expression of Antixenosis in Soybean to Anticarsia gemmatalis and Spodoptera frugiperda (Lepidoptera: Noctuidae)
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Júnior, Arlindo Leal Boiça, Souza, Bruno Henrique Sardinha De, Costa, Eduardo Neves, Ribeiro, Zulene Antonio, and Stout, Michael Joseph
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- 2015
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11. Resistance of bean genotypes to Chrysodeixis includens and influence of mycorrhizas and silicon on corn and soybean tolerance to pests
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Ulhoa, Lucas Adjuto, Universidade Estadual Paulista (Unesp), Boiça Junior, Arlindo Leal [UNESP], and Stout, Michael Joseph [UNESP]
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Glycine max ,Lagartas ,The soybean looper ,Zea mays rugosa ,Phaseolus vulgaris ,Feijão - Abstract
Submitted by Lucas Adjuto Ulhoa (lucas.ulhoa@unesp.br) on 2022-10-14T03:11:59Z No. of bitstreams: 1 Tese - Lucas Adjuto Ulhoa.pdf: 1504518 bytes, checksum: a06c2939bc4743fa67578a72f1abe054 (MD5) Approved for entry into archive by Laudicélia Martins Arantes (lm.arantes@unesp.br) on 2022-10-14T11:29:06Z (GMT) No. of bitstreams: 1 ulhoa_la_dr_jabo.pdf: 1549683 bytes, checksum: edad671a238fb87f579a713e79b85d5c (MD5) Made available in DSpace on 2022-10-14T11:29:06Z (GMT). No. of bitstreams: 1 ulhoa_la_dr_jabo.pdf: 1549683 bytes, checksum: edad671a238fb87f579a713e79b85d5c (MD5) Previous issue date: 2022-09-02 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) O controle de Crysodeixis includens na cultura do feijão e Spodoptera frugiperda nas culturas da soja e do milho tem sido realizado principalmente através da aplicação de inseticidas químicos e/ou do uso de plantas transgênicas que expressam as proteínas inseticidas de Bacillus thuringiensis (Bt). Entretanto, estes métodos de controle podem impor uma forte pressão de seleção nas populações das lagartas, favorecendo a evolução da resistência. Portanto, o uso de genótipos resistentes a insetos-praga e a aplicação de Silício (Si) e Fungos Micorrízicos Arbusculares (FMAs) para induzir a resistência e/ou melhorar o desenvolvimento das plantas, são alternativas promissoras para serem usadas no manejo integrado desses insetos-praga. As plantas resistentes possuem complexos mecanismos bioquímicos e morfológicos de defesa contra pragas. O Si absorvido pelas plantas é depositado no tecido das folhas, formando uma barreira mecânica que dificulta a alimentação do inseto herbívoro. Os FMAs formam associações com as raízes e ajudam as plantas na absorção de nutrientes e água. Os objetivos deste trabalho foram avaliar a expressão de possíveis fontes de resistência constitutiva e induzida de doze genótipos comerciais de feijão à C. includens. Além disso, avaliar os efeitos da aplicação de Si e FMA no desenvolvimento e na tolerância de soja e milho a S. frugiperda em casa de vegetação e de soja as diferentes pragas no campo. Foram realizados ensaios de atratividade, preferência alimentar, índices nutricionais e antibiose para selecionar genótipos de feijão com fontes de resistência á C. includens. Além disso, foi avaliado o desenvolvimento das plantas e de S. frugiperda, os danos causados pelos insetos, o nível populacional de espécies de pragas e a qualidade das sementes colhidas nos diferentes tratamentos com Si e FMA. Analisando os dados de resistência constitutiva, os genótipos BRS MG Madrepérola (antixenose e antibiose), BRS Sublime (antixenose) e IAC 1850 (antibiose) foram resistentes. Os seguintes genótipos apresentaram resistência induzida: BRS Sublime (antixenose), IAC 1850 (antixenose), Pérola (antixenose e antibiose), IAC Sintonia (Nova seleção) (antixenose e antibiose), BRS FC 402 (antixenose e antibiose) e ANFC 9 (antibiose). Os testes em casa de vegetação e campo demonstraram que a inoculação e colonização de FMAs nas raízes e a aplicação de Si no solo individualmente ou em conjunto (FMA+Si) influenciaram positivamente em alguns parâmetros o desenvolvimento, resistência e tolerância das plantas de milho e soja. Os resultados deste trabalho são importantes para buscar alternativas sustentáveis no cultivo dessas importantes culturas, como a seleção de novas fontes de resistência do feijão e demonstração que a aplicação de Si e FMA no solo pode ser benéfico para as culturas do milho e da soja. The control of Crysodeixis includens in the bean crop and Spodoptera frugiperda in the soybean and corn crops has been carried out mainly through the application of chemical insecticides and/or the use of transgenic plants that express the insecticidal proteins of Bacillus thuringiensis (Bt). However, these control methods can impose strong selection pressure on caterpillar populations, favoring the evolution of resistance. Therefore, the use of insect-pest resistant genotypes and the application of Silicon (Si) and Arbuscular Mycorrhizal Fungi (AMF) to induce resistance and/or improve plant development are promising alternatives to be used in the integrated management of these insects-Prague. Resistant plants have complex biochemical and morphological defense mechanisms against pests. The Si absorbed by the plants is deposited in the leaf tissue, forming a mechanical barrier that makes it difficult for the herbivorous insect to feed. AMFs form associations with the roots and help plants absorb nutrients and water. The objectives of this work were to evaluate the expression of possible sources of constitutive and induced resistance of twelve commercial bean genotypes to C. includens. In addition, to evaluate the effects of Si and AMF application on the development and tolerance of soybean and corn to S. frugiperda in a greenhouse and soybean to different pests in the field. Attractiveness, food preference, nutritional indices and antibiosis assays were carried out to select bean genotypes with sources of resistance to C. includens. Furthermore, the development of plants and S. frugiperda, the damage caused by insects, the population level of pest species and the quality of the seeds collected in the different treatments with Si and AMF were evaluated. Analyzing the constitutive resistance data, the genotypes BRS MG Madrepérola (antixenosis and antibiosis), BRS Sublime (antixenosis) and IAC 1850 (antibiosis) were resistant. The following genotypes showed induced resistance: BRS Sublime (antixenosis), IAC 1850 (antixenosis), Pérola (antixenosis and antibiosis), IAC Sintonia (Nova seleção) (antixenosis and antibiosis), BRS FC 402 (antixenosis and antibiosis) and ANFC 9 (antibiosis). The tests in greenhouse and field showed that the inoculation and colonization of AMFs in the roots and the application of Si in the soil individually or together (AMF+Si) positively influenced the development, resistance and tolerance of maize and soybeans plants in some parameters. The results of this work are important to seek sustainable alternatives in the cultivation of these important crops, such as the selection of new sources of bean resistance and demonstration that the application of Si and FMA in the soil can be beneficial for corn and soybean crops. 88882.433791/2019-01
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- 2022
12. Research methodology, levels in the categories of constitutive resistance in soybean genotypes and induced resistance against Heliothis virescens and the defense mechanisms envolved
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Eduardo, Wellington Ivo [UNESP], Universidade Estadual Paulista (Unesp), Boiça Júnior, Arlindo Leal [UNESP], and Stout, Michael Joseph [UNESP]
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chemical analyses ,resistência de plantas ao ataque de insetos ,host plant resistance ,morphological analyses ,análises bioquímicas ,análises morfológicas ,Glycine max (L.) ,Tobaco budworm - Abstract
Submitted by WELLINGTON IVO EDUARDO null (wellington_ie@hotmail.com) on 2018-03-02T21:56:43Z No. of bitstreams: 1 Tese_Wellington_Ivo_Eduardo.pdf: 2274097 bytes, checksum: 93aec24e46ac9b4cc80b0d41df05e805 (MD5) Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-03-05T18:08:57Z (GMT) No. of bitstreams: 1 eduardo_wi_dr_jabo.pdf: 2274097 bytes, checksum: 93aec24e46ac9b4cc80b0d41df05e805 (MD5) Made available in DSpace on 2018-03-05T18:08:57Z (GMT). No. of bitstreams: 1 eduardo_wi_dr_jabo.pdf: 2274097 bytes, checksum: 93aec24e46ac9b4cc80b0d41df05e805 (MD5) Previous issue date: 2018-02-07 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Existem poucos estudos a respeito da utilização de genótipos de soja resistentes no manejo de Heliothis virescens (Fabricius, 1781) (Lepidoptera: Noctuidae) e com o aumento de seu ataque nas últimas safras, eles se tornam necessários. Para isso é primordial a padronização de métodos de pesquisa para obtenção desses genótipos, assim como, estudos sobre os mecanismos de defesas e a indução de resistência dessas plantas frente ao ataque desta praga. Com isso, os objetivos deste trabalho foram avaliar metodologias de pesquisa para testes de resistência nas categorias não preferência para alimentação, não preferência para oviposição e antibiose e classificar os genótipos de soja a H. virescens em níveis de resistência; além de verificar a expressão de resistência induzida sob diferentes níveis de injúrias e tempo após as injúrias e analisar alguns possíveis mecanismos morfológicos e químicos envolvidos com a resistência constitutiva e induzida desses genótipos. Nos experimentos de metodologia de pesquisa para testes de resistência na categoria não preferência para alimentação foi possível observar que a densidade de nove lagartas recém-eclodidas e duas lagartas de seis dias de idade por genótipo e folíolos novos de plantas em estádio vegetativos foram os mais indicados para a realização dos testes de resistência com genótipos. Na categoria não preferência para oviposição, as densidades de casais liberadas por genótipo não influenciaram na diferenciação dos genótipos de soja. A quantidade de ovos por fêmea em densidades de dois casais por genótipo não diferiu das densidades de um e três casais, desta forma a densidade de dois casais foi a selecionada para os testes de resistência na categoria de oviposição com os genótipos; em relação a escolha da estrutura vegetal mais apropriada para avaliação, também não houve diferenciação entre os genótipos resistentes e suscetíveis, optando-se assim, em contar os ovos de todas as estruturas vegetais da planta nos testes posteriores desta categoria; ainda na categoria não preferência para oviposição, o estádio fenológico em que se utilizou a planta também não interferiu na diferenciação dos genótipos, adotando-se assim, utilizar para os testes posteriores plantas em estádio vegetativo pela a rapidez na obtenção e facilidade no manejo das plantas. Nos testes de metodologia de pesquisa na categoria antibiose, determinou-se a utilização da densidade de uma lagarta em recipientes de 150 ml por proporcionar maior diferenciação entre o genótipo resistente do suscetível principalmente na viabilidade de lagartas aos 12 dias e viabilidade larval total; nos testes para determinação da estrutura vegetal, determinou-se utilizar somente os folíolos por diferenciar melhor o genótipo resistente do suscetível nos parâmetros peso de lagartas aos 12 dias, viabilidade larval e peso de pupas. Com base nesses resultados foram realizados os testes de resistência constitutiva de genótipos de soja a H. virescens nas categorias não preferência para alimentação, não preferência para oviposição e antibiose, utilizando densidades de lagartas e casais, tamanho de recipiente, estrutura vegetal e plantas em estádio fenológico determinados anteriormente pelos testes de metodologia de pesquisa. Nos testes na categoria não preferência para alimentação, dentre os 26 materiais avaliados, os genótipos IAC-100, Dowling, UFUS Impacta, UFUS Capim Branco e UFUS Milionária se destacaram como vi resistentes, enquanto os genótipos BR-16, CD-208, UFUS Xavante e M8230RR foram classificados como suscetíveis a H. virescens. Esses genótipos classificados como resistentes e suscetíveis foram submetidos aos testes de resistência constitutiva na categoria não preferência para oviposição e o genótipo UFUS Impacta se destacou por expressar resistência. Na categoria antibiose, os genótipos UFUS Xavante e IAC-100 expressaram resistência a H. virescens e o genótipo CD-208 foi classificado como altamente suscetível. Nos testes indução de resistência para determinar o nível de injúria necessária para que plantas de soja fossem induzidas a expressar resistência contra H. virescens observou que todos os níveis de injúria foram suficientes para essas plantas expressarem resistência a esta praga. Determinou-se ainda que no período de 72 a 144 horas após as plantas serem injuriadas por H. virescens ocorreu a maior expressão de resistência. Para elucidar esses resultados foram realizadas análises morfológicas e químicas nas plantas, sendo possível relacionar a densidade de tricomas com a menor oviposição de H. virescens; as concentrações de fibras e lignina, assim como dos flavonoides rutina e hesperidina com a resistência constitutiva de plantas de soja; além de verificar um aumento dos compostos fenólicos com o passar do tempo após as plantas serem injuriadas. Conclui-se assim que, as densidades de lagartas de H. virescens que melhor diferenciam o genótipo de soja resistente do suscetível são nove e duas, para lagartas recém-eclodidas e de seis dias de idade, respectivamente; os folíolos novos de plantas em estádio vegetativo discriminam melhor o genótipo resistente do suscetível; nos testes de não preferência para oviposição não há diferenciação dos materiais resistentes e suscetíveis nas diferentes densidades de casais, estruturas vegetais e estádios fenológicos; a densidade de uma lagarta de H. virescens e o recipiente de plástico com volume de 150 ml assim como as folhas são melhor discrimina os genótipos de soja resistente do suscetível em teste de resistência da categoria antibiose; os genótipos IAC-100 e UFUS Milionária são altamente resistentes e os genótipos Dowling, UFUS Capim Branco, UFUS Impacta são moderadamente resistentes a H. virescens na categoria não preferência para alimentação; o genótipo UFUS Impacta é resistente a H. virescens na categoria não preferência para oviposição; o genótipo UFUS Xavante é altamente resistente e o genótipo IAC-100 é moderadamente resistente a H. virescens na categoria antibiose; plantas de soja do genótipo 84 Davis expressam resistência induzida a H. virescens depois de sofrerem injúrias de 25, 50 e 75% no trifólio mais velho por essa praga; plantas de soja do genótipo 84 Davis expressam resistência induzida a H. virescens a partir de 36h do ataque desta praga, aumentando a resistência até 200h após do ataque, diminuindo após este período; os tricomas são um dos possíveis mecanismos de defesa relacionados com a oviposição das mariposas e não alimentação em vagens de lagartas jovens; o baixo teor de taninos e compostos fenólicos totais estão relacionados com a preferência das lagartas por grãos em desenvolvimento ao invés de folhas; lagartas recém-eclodidas e com seis dias de idade de H. virescens preferem se alimentar de folhas com menores concentrações de fibras e ligninas; os flavonoides rutina e hesperidina estão relacionados com a resistência da categoria não preferência para alimentação em genótipos IAC-100, Dowling, UFUS Capim Branco, UFUS Impacta e UFUS Milionária por H. virescens. There are few studies on the use of resistant soybean genotypes in the management of Heliothis virescens (Fabricius, 1781) (Lepidoptera: Noctuidae) and with the increase of their attack in the last few seasons, these study become necessary, being important a standardization of the research methods to obtain these genotypes, as well as, studies on the defense mechanisms and the resistance induction of these plants against the attack of this pest. Thus, the aims of this work were to evaluate research methodologies for resistance tests in the categories, non-preference for feeding, non-preference for oviposition and antibiosis, and to classify the soybean genotypes in resistance levels against H. virescens in these categories; besides verifying the expression of induced resistance under injuries levels and time after the injuries caused by H. virescens, and to analyze some possible morphological and chemical mechanisms involved with the constitutive and induced resistance of these genotypes. In the research methodology experiments for resistance tests in the non-preference for feeding category was possible to observe that the density of nine caterpillars neonates and two caterpillars with six-day old per genotype; new leaf of plants in vegetative stage plants were the most indicated for the performance of resistance tests with genotypes soybean. In the non-preference for oviposition category, the couples densities released per genotype did not influence in the distition of the soybean genotypes; in parallel, the amount of lay eggs per female at densities of two couples per genotype did not differ from the densities of one and three couples, in this way the density of two couples was selected for the resistance tests in the non-preference for oviposition category with the genotypes soybean against H. virescens; in relation to the choice of the most appropriate plant structure for evaluation of the resistance tests, there was also no differentiation between the resistant and susceptible genotypes, thus choosing to count the eggs of all structures of the plant in the later resistance tests of this category; the phenological stage in which the plant was used also did not interfere in the differentiation of the genotypes, using, at the later resistance tests, plants at the vegetative stage by the speed in obtaining and ease in the management of the plants. In turn, in the research methodology tests in the antibiosis category, it was determined the use of the density of a caterpillar per containers of 150 ml, for providing greater differentiation between the resistant genotype of the susceptible, mainly in the larval viability at 12 days and larval viability; in the tests to determine the plant structure more suitable for resistance tests, the leaves alone were choose because in these structures there was a greater differentiation of the resistant genotype than susceptible genotype in the parameters larval weight at 12 days, larval viability and pupal weight. Based on these results, constitutive resistance tests of soybean genotypes to H. virescens were performed in the categories non-preference for feeding, no preference for oviposition and antibiosis, using larvae and couples densities, container size, plant structure and plants in phenological stage determined previously by the research methodology tests. In the tests of the non-preference for feeding category, among the 26 genotypes evaluated, the genotypes IAC-100, Dowling, UFUS Impacta, UFUS Capim Branco and UFUS viii Millionaria were the genotypes most resistant, while genotypes BR-16, CD-208, UFUS Xavante and M8230RR were classified as susceptible to H. virescens. These genotypes classified as resistant and susceptible were submitted to constitutive resistance tests in the non-preference for oviposition category and the UFUS genotype. Impacta was noted for expressing resistance to this pest. In the antibiosis category the UFUS Xavante and IAC-100 genotypes expressed resistance to H. virescens, while the CD-208 genotype was classified as highly susceptible. In the induced resistance tests to determine the level of injury required for soybean plants to be induced to express resistance against H. virescens was observed that all injury levels tested were sufficient for these plants to express resistance to this pest We also determined that in the period of 72 to 144 hours after the plants were be injured by H. virescens was respnsable by greatest expression of resistance against this pest occurred among the times tested. In the attempt to elucidate these results, morphological and chemical analyzes of the plants were carried out, being possible to relate the trichomes density with the lowest oviposition of H. virescens; the concentrations of fiber and lignin, as well as the flavonoids rutin and hesperidin with the constitutive resistance of soybean plants to this pest; in addition, we noticed that there was an increase of the phenolic compounds with the increase of the time after the injuries in plants. It is concluded that the densities of H. virescens caterpillars that best differentiate susceptible and resistant soybean genotype are nine and two neonates and six-day old caterpillars, respectively; new folioles of plants in vegetative stage better discriminate the susceptible and resistant genotype; in the non-preference for oviposition tests there is no differentiation of the resistant and susceptible materials for the different densities of couples, plant structures and phenological stages; the density of a H. virescens caterpillar and the plastic container with a volume of 150 ml as well as the leaves are best discriminated against susceptible soybean genotypes susceptible in antibiosis resistance test; in the non-preference category for feeding the IAC-100 and UFUS Millionaria genotypes are highly resistant and the Dowling, UFUS Capim Branco and UFUS Impacta genotypes are moderately resistant to H. virescens; in the non-preference category for oviposition the genotype UFUS Impacta is resistant to H. virescens; in the antibiosis category the UFUS Xavante genotype is highly resistant and the IAC-100 genotype is moderately resistant to H. virescens; soybean plants of the Davis 84 genotype express induced resistance to H. virescens after suffering 25, 50 and 75% injuries in the older trefoil by this pest; soybean plants of the Davis 84 genotype express induced resistance to H. virescens from 36 hours of the attack of this pest, increasing resistance up to 200 h after the attack, decreasing after this period; trichomes are one of the possible defense mechanisms related to oviposition of moths and not feeding on young caterpillar pods; the low content of tannins and total phenolic compounds are related to the preference of caterpillars for developing grains rather than leaves; Neonates and six-day-old caterpillars of H. virescens prefer to feed on leaves with lower fiber and lignin concentrations; the flavonoids rutin and hesperidin are related to resistance of the non-preference category for feeding in genotypes IAC-100, Dowling, UFUS Capim Branco, UFUS Impacta and UFUS Millionaire by H. virescens. 2014/08373-3
- Published
- 2018
13. Fatores e mecanismos que influenciam a resistência em soja a Anticarsia gemmatalis Hübner e Spodoptera frugiperda (J. E. Smith)
- Author
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Souza, Bruno Henrique Sardinha de [UNESP], Universidade Estadual Paulista (Unesp), Boiça Júnior, Arlindo Leal [UNESP], and Stout, Michael Joseph [UNESP]
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Inibidores da tripsina ,Enzimas ,Lagarta da soja ,Agricultural pests ,Flavonoides ,Soja - Doenças e pragas ,Plantas - Resistencia a doenças e pragas - Abstract
Made available in DSpace on 2015-04-09T12:28:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-28Bitstream added on 2015-04-09T12:47:39Z : No. of bitstreams: 1 000817707.pdf: 784315 bytes, checksum: 7b270c28b49a7aab4fb0d82140c6c370 (MD5) A lagarta-da-soja Anticarsia gemmatalis Hübner e a lagarta-militar Spodoptera frugiperda (J. E. Smith) são duas das principais pragas desfolhadoras da cultura da soja. Entre os métodos disponíveis para seu controle destaca-se o uso de genótipos que apresentam moderada e alta resistência a insetos. No entanto, diversos fatores, inerentes à planta ou ao inseto, podem influenciar a expressão da resistência nas plantas. Desse modo, esse trabalho teve o objetivo de avaliar possíveis fatores que possam influenciar a expressão da resistência em soja, testando-se as hipóteses de que flavonoides, nutrientes, enzimas oxidativas, compostos fenólicos, proteínas e inibidores de proteinase possam ser alguns dos mecanismos responsáveis pela resistência à lagarta-da-soja e lagarta-militar. Três experimentos foram realizados a fim de elucidar essas questões. O primeiro experimento avaliou a influência dos seguintes fatores na expressão de antixenose nos genótipos resistente IAC 100 e suscetível BRSGO 8360 a ambas as espécies de insetos em testes de preferência alimentar com e sem chance de escolha: uma lagarta versus duas lagartas por disco foliar; uso de lagartas sem interrução de alimentação versus com suspensão de alimentação por três horas antes do ensaio; disco foliar versus folíolo inteiro; parte superior versus parte inferior da planta; e estádio vegetativo versus estádio reprodutivo. O segundo experimento avaliou a influência da parte superior versus inferior da planta e de plantas em estádio vegetativo versus plantas em estádio reprodutivo na expressão de antibiose a A. gemmatalis e S. frugiperda nos genótipos resistente PI 227687 e suscetível IGRA RA 626 RR. Além disso, foram avaliadas as concentrações de nutrientes e flavonoides como possíveis mecanismos responsáveis pela resistência em soja. Os macronutrientes quantificados nas folhas dos genótipos de soja provenientes dos respectivos tratamentos ... The velvetbean caterpillar Anticarsia gemmatalis Hübner and the fall armyworm Spodoptera frugiperda (J. E. Smith) are two of the major defoliating pests of soybeans. Among the methods available for their control, the use of genotypes possessing moderate and high resistance stands out. However, numerous factors, inherent to the plant or to the insect, may influence the expression of resistance in plants. Thus, this work aimed to evaluate potential factors influencing the expression of resistance in soybeans, and we tested the hypotheses that flavonoids, nutrients, oxidative enzymes, phenolics, proteins, and proteinase inhibitors may be some of the mechanisms responsible for resistance to the velvetbean caterpillar and fall armyworm. Three experiments were performed in order to elucidate these issues. The first experiment evaluated the influence of the following factors on the expression of antixenosis in the resistant genotype IAC 100 and susceptible genotype BRSGO 8360 to both insects in free-choice and no-choice feeding assays: one larva versus two larvae per leaf disc; use of non-starved larvae versus larvae starved for three hours prior to the assay; leaf disc versus entire leaflet; upper part versus lower part of plants; vegetative growth stage versus reproductive stage. The second experiment assessed the influence of the upper part versus lower part of the plant, and plants at vegetative growth stage versus reproductive stage on the expression of antibiosis to A. gemmatalis and S. frugiperda in the resistant genotype PI 227687 and susceptible genotype IGRA RA 626 RR. In addition, the concentration of nutrients and flavonoids were evaluated as potentital mechanisms responsible for resistance in soybeans. The macronutrientes quantified in the leaves of the soybean genotypes from the respective treatments were N, P, K, Ca, Mg, and S; the quantified micronutrients were B, Cu, Fe, Mn, and Zn; among the flavonoids, we quantified ...
- Published
- 2014
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