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Sample records for antibiosis

  1. Study on the antibiosis of exudate JK-91-b against rice sheath blight (SHB)

    Institute of Scientific and Technical Information of China (English)

    CHENZhiyi; YINShangzhi; GAOXianting

    1994-01-01

    Antagonistic bacterial strain 91-b possessed stronger antagonistic ability against SHB infection. The control effects of the bacterization against SHB were 58.1% in greenhouse and 45.1% in paddy. The effect of antibiosis JK-91-b exudated by strain 91-b was studied in the present research.

  2. Antibiosis by Pantoea agglomerans biocontrol strain E325 against Erwinia amylovora on apple blossom stigmas

    Science.gov (United States)

    Pantoea agglomerans E325, the active ingredient in a commercial product for fire blight control, was previously shown in vitro to produce a unique alkaline- and phosphate-sensitive antibiotic specific to Erwinia amylovora. Antibiosis was evaluated as a mode of antagonism on blossom stigmas using two...

  3. Antibiosis functions during interactions of Trichoderma afroharzianum and Trichoderma gamsii with plant pathogenic Rhizoctonia and Pythium.

    Science.gov (United States)

    Zhang, Xinjian; Harvey, Paul R; Stummer, Belinda E; Warren, Rosemary A; Zhang, Guangzhi; Guo, Kai; Li, Jishun; Yang, Hetong

    2015-09-01

    Trichoderma afroharzianum is one of the best characterized Trichoderma species, and strains have been utilized as plant disease suppressive inoculants. In contrast, Trichoderma gamsii has only recently been described, and there is limited knowledge of its disease suppressive efficacies. Comparative studies of changes in gene expression during interactions of these species with their target plant pathogens will provide fundamental information on pathogen antibiosis functions. In the present study, we used complementary DNA amplified fragment length polymorphism (cDNA-AFLP) analysis to investigate changes in transcript profiling of T. afroharzianum strain LTR-2 and T. gamsii strain Tk7a during in vitro interactions with plant pathogenic Rhizoctonia solani and Pythium irregulare. Considerable differences were resolved in the overall expression profiles of strains LTR-2 and Tk7a when challenged with either plant pathogen. In strain LTR-2, previously reported mycoparasitism-related genes such as chitinase, polyketide synthase, and non-ribosomal peptide synthetase were found to be differentially expressed. This was not so for strain Tk7a, with the only previously reported antibiosis-associated genes being small secreted cysteine-rich proteins. Although only one differentially expressed gene was common to both strains LTR-2 and Tk7a, numerous genes reportedly associated with pathogen antibiosis processes were differentially expressed in both strains, including degradative enzymes and membrane transport proteins. A number of novel potential antibiosis-related transcripts were found from strains LTR-2 and Tk7a and remain to be identified. The expression kinetics of 20 Trichoderma (10 from strain LTR-2, 10 from strain Tk7a) transcript-derived fragments (TDFs) were quantified by quantitative reverse transcription PCR (RT-qPCR) at pre- and post-mycelia contact stages of Trichoderma-prey interactions, thereby confirming differential gene expression. Collectively, this research

  4. Genetic mechanisms underlying apimaysin and maysin synthesis and corn earworm antibiosis in maize (Zea mays L.).

    OpenAIRE

    Lee, E A; Byrne, P.F.; McMullen, M D; Snook, M E; Wiseman, B. R.; Widstrom, N W; Coe, E. H.

    1998-01-01

    C-glycosyl flavones in maize silks confer resistance (i.e., antibiosis) to corn earworm (Helicoverpa zea [Boddie]) larvae and are distinguished by their B-ring substitutions, with maysin and apimaysin being the di- and monohydroxy B-ring forms, respectively. Herein, we examine the genetic mechanisms underlying the synthesis of maysin and apimaysin and the corresponding effects on corn earworm larval growth. Using an F2 population, we found a quantitative trait locus (QTL), rem1, which account...

  5. Antibiosis in Soybean Genotypes and the Resistance Levels to Spodoptera eridania (Cramer) (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Souza, B H S; Silva, A G; Janini, J C; Boica Júnior, A L

    2014-12-01

    The southern armyworm (SAW) Spodoptera eridania (Cramer) is one of the most common armyworm species defoliating soybeans. Preliminary screening trials have indicated that some soybean genotypes exhibit resistance to SAW. Therefore, in this study, we evaluated the development of SAW larvae fed on ten soybean genotypes in order to identify genotypes with antibiosis-type resistance. Neonate SAW larvae were daily fed with young leaves collected from plants at the vegetative growth stages V4-V5. Larval development and survival were recorded. Genotypes PI 227687 and PI 227682 delayed larval, pupal, and larva-adult development and yielded larvae with the lowest weight and survival and pupae with the lowest weight. Genotypes IAC 100 and DM 339 also negatively affected larval and pupal development and larval survival but at a lower level. Based on our results, the soybean lines PI 227687 and PI 227682 could be used as sources of genes for soybean breeding programs aiming to develop high yield, SAW-resistant cultivars. Moreover, further trials must be carried out under field conditions to validate if the commercial cultivars IAC 100 and DM 339, which expressed moderate levels of antibiosis-type resistance in the laboratory, are effective in suppressing SAW larvae populations. PMID:27194067

  6. Isolation and Identification of an Endophytic Strain with Antibiosis Ability from Davidia involucrate Brail.

    Institute of Scientific and Technical Information of China (English)

    NI Guo-rong; PAN Xiao-hua; TU Guo-quan; KUANG Fu-yuan; WEI Sai-jin

    2011-01-01

    [Objective]The aim was to isolate and identify an endophytic bacteria strain with antimicrobial activity from Davidia involucrate Brail.[Method]Endophytic strain with antibiosis ability was isolated from D.involucrate Brail by using cylinder-plate method.Then,it was identified through physiological and biochemical tests,16S rDNA homology analysis as well as some gene-specific sequence analysis.[Result]B221 stain had antimicrobial activity against a variety of rice plant pathogens,and it was identified as Bacillus subtilis.[Conclusion]This study enriches the research on endophyte within D.involucrate Brail,application of Bacillus bio-control,and therefore has laid a good foundation for the development of fungus used in biological control of crop pathogens.

  7. Role and prevalence of antibiosis and the related resistance genes in the environment

    DEFF Research Database (Denmark)

    It becomes increasingly clear that the basis of antibiotic resistance problem among bacterial pathogens is not confined to the borders of clinical microbiology but has broader ecological and evolutionary associations. This Research Topic “Role and prevalence of antibiosis and the related resistance...... genes in the environment” in Frontiers in Microbiology, section Antimicrobials, Resistance and Chemotherapy, presents the examples of occurrence and diversity of antibiotic resistance genes in the wide range of environments, from the grasslands of the Colombian Andes, to the dairy farms and small animal...... veterinary hospitals in the United Stated, and to the various environments of Continental Europe and Indochina. Besides, various genetic mechanisms and selection/co-selection factors contributing to the dissemination and maintenance of antibiotic resistance genes are presented. The topic is finalized...

  8. Characterization of antibiosis and antixenosis to the woolly poplar aphid (Hemiptera: Aphididae) in the bark of different poplar genotypes.

    Science.gov (United States)

    Pointeau, Sophie; Ameline, Arnaud; Sallé, Aurélien; Bankhead-Dronnet, Stéphanie; Lieutier, François

    2013-02-01

    The woolly poplar aphid, Phloeomyzus passerinii (Signoret) (Hemiptera: Aphididae), is a major pest of poplar plantations in the Mediterranean basin and the Near East. Aphids colonize poplar trunks and feed upon the cortical parenchyma. Despite the economic importance of poplar, little is known about the mechanisms involved in poplar resistance to this pest. However, Populus x canadensis Moench genotypes show various levels of resistance to P. passerinii. This study has investigated the type of poplar resistance (antibiosis or antixenosis) by assessing aphid settlement, physiology (survival, development, and reproduction), and stylet penetration behavior (electrical penetration graph) on three P. x canadensis genotypes; '1214' (susceptible), 'Brenta' (resistant), and '145/51' (intermediate). Because settlement was reduced, the highly resistant genotype Brenta exhibited surface antixenosis. In addition, nymphal survival was null on Brenta, and twice less adult aphid initiated a sustained intracellular phase in the cortical parenchyma of that genotype compared with the other two genotypes. Thus, Brenta also showed parenchyma-located antixenosis coupled with antibiosis characteristic. In contrast, P. passerinii had no difficulty to initiate a sustained ingestion in the cortical parenchyma of the intermediate genotype 145/51, but decreased fecundity and lower intrinsic rate of natural increase were clear expressions of antibiosis. PMID:23448064

  9. Antibiosis of Trichoderma spp strains native to northeastern Mexico against the pathogenic fungus Macrophomina phaseolina

    Directory of Open Access Journals (Sweden)

    José Luis Hernández Mendoza

    2015-12-01

    Full Text Available Abstract Sampling of agricultural soils from the Mexican northeastern region was performed to detect Trichoderma spp., genetically characterize it, and assess its potential use as a biologic control agent against Macrophomina phaseolina. M. phaseolina is a phytopathogen that attacks over 500 species of cultivated plants and causes heavy losses in the regional sorghum crop. Sampling was performed immediately after sorghum or corn harvest in an area that was approximately 170 km from the Mexico-USA border. Sixteen isolates were obtained in total. Using colony morphology and sequencing the internal transcribed spacers (ITS 1 and 4 of 18S rDNA, 14 strains were identified as Trichoderma harzianum, T. koningiopsis and T. virens. Subsequently, their antagonistic activity against M. phaseolina was evaluated in vitro, and 11 isolates showed antagonism by competition and stopped M. phaseolina growth. In 4 of these isolates, the antibiosis phenomenon was observed through the formation of an intermediate band without growth between colonies. One strain, HTE808, was identified as Trichoderma koningiopsis and grew rapidly; when it came into contact with the M. phaseolina colony, it continued to grow and sporulated until it covered the entire petri dish. Microscopic examination confirmed that it has a high level of hyperparasitism and is thus considered to have high potential for use in the control of this phytopathogen.

  10. Antibiosis and antixenosis to Aphis gossypii (Homoptera: Aphididac) in Colocasia esculenta.

    Science.gov (United States)

    Coleson, Jenifer L; Miller, Ross H

    2005-06-01

    Fifty cultivars of taro, Colocasia esculenta (L.) Schott (Araceae), collected from islands in Micronesia and Polynesia, eight cultivars from the University of Hawaii's taro germplasm collection, and a closely related aroid, Xanthosorna sagittifolium (L.) (Araceae), were screened for antibiosis and antixenosis to Aphis gossypii Clover. Life history data for A. gossypii were collected by assessing survivorship and fecundity of aphids caged on taro leaves in the field. Significant differences in aphid reproductive rate and longevity were observed among the taro cultivars, and cultivars were ranked from most resistant to most susceptible. Antixenosis was assayed in the laboratory in a multiround choice test where A. gossypii were offered four leaf discs excised from different taro cultivars. Additionally, field observations of aphid abundance on taro cultivars were made to corroborate clip cage studies and laboratory experiments. 'Iliuaua','Rumung Mary','Maria', 'Ketan 36', and'Agaga' were the most resistant in terms of reducing aphid fecundity and survivorship, whereas the Iliuana,'Purple', 'TC-83001', and 'Putih 24' were least preferred in aphid choice tests. X. sagittifolium consistently exhibited strong aphid resistance. Resistant cultivars identified in this study may form the basis of breeding programs seeking to combine aphid resistance with other desirable agronomic traits in taro.

  11. Antibiosis of Trichoderma spp strains native to northeastern Mexico against the pathogenic fungus Macrophomina phaseolina.

    Science.gov (United States)

    Mendoza, José Luis Hernández; Pérez, María Isabel Sánchez; Prieto, Juan Manuel González; Velásquez, Jesús DiCarlo Quiroz; Olivares, Jesús Gerardo García; Langarica, Homar Rene Gill

    2015-01-01

    Sampling of agricultural soils from the Mexican northeastern region was performed to detect Trichoderma spp., genetically characterize it, and assess its potential use as a biologic control agent against Macrophomina phaseolina. M. phaseolina is a phytopathogen that attacks over 500 species of cultivated plants and causes heavy losses in the regional sorghum crop. Sampling was performed immediately after sorghum or corn harvest in an area that was approximately 170 km from the Mexico-USA border. Sixteen isolates were obtained in total. Using colony morphology and sequencing the internal transcribed spacers (ITS) 1 and 4 of 18S rDNA, 14 strains were identified as Trichoderma harzianum, T. koningiopsis and T. virens. Subsequently, their antagonistic activity against M. phaseolina was evaluated in vitro, and 11 isolates showed antagonism by competition and stopped M. phaseolina growth. In 4 of these isolates, the antibiosis phenomenon was observed through the formation of an intermediate band without growth between colonies. One strain, HTE808, was identified as Trichoderma koningiopsis and grew rapidly; when it came into contact with the M. phaseolina colony, it continued to grow and sporulated until it covered the entire petri dish. Microscopic examination confirmed that it has a high level of hyperparasitism and is thus considered to have high potential for use in the control of this phytopathogen. PMID:26691467

  12. Novel Strategies for Combating Pathogenic Biofilms Using Plant Products and Microbial Antibiosis.

    Science.gov (United States)

    Khan, Mohd S A; Lee, Jintae

    2015-01-01

    Microorganisms prefer to live in three-dimensional self-organized communities (biofilms), and this behavior provides microbial pathogens inhabiting various sites in the human body or on medical devices with survival advantages. In fact, pathogens in the biofilm stage exhibit up to a thousandfold more tolerance to conventional antimicrobial agents, and thus, they are difficult to eradicate and biofilms generated during acute infections become persistent, chronic, and recurrent. Consequently, novel strategies are being sought to control biofilm associated infections. The developmental strategies used include improved drug delivery and the penetration of biofilm matrices, and in particular, natural products that interfere with virulence and cross talk between microbial cells are being investigated as potential anti-biofilm agents. This article provides an overview of existing and promising biofilm control strategies based on plant and microbial products. Control strategies like quorum sensing inhibition, microbial antibiosis, and the uses of phages and probiotics are reviewed along with current developments in high throughput screening and in our understanding of structure activity relationships related to the regulation of biofilms by small molecules. PMID:26343132

  13. Assesing Bemisia tabaci (Genn. biotype B resistance in soybean genotypes: Antixenosis and antibiosis Evaluación de la resistencia de genotipos de soya a Bemisia tabaci (Genn. biotipo B: Antixenosis y antibiosis

    Directory of Open Access Journals (Sweden)

    José Paulo Gonçalves Franco da Silva

    2012-12-01

    Full Text Available Since it was first reported in Brazil in the 1990s, the B biotype of silverleaf whitefly (Bemisia tabaci Genn., Hemiptera: Aleyrodidae has been recognized as an important pest in soybeans (Glycine max L., reducing the productivity of this legume species in some areas of the country. As an alternative to chemical control, the use of resistant genotypes represents an important tool for integrated pest management (IPM. This study evaluated the performance of 10 soybean genotypes prior to whitefly infestation, by testing attractiveness and preference for oviposition in the greenhouse and antibiosis in the laboratory. In a multiple-choice test, 'IAC-17' was the least attractive to insects. In a no-choice test, 'IAC-17' was the least attractive for egg deposition, indicating the occurrence of non-preference for oviposition on this genotype. Trichome density was positively correlated with the oviposition site and may be associated with the resistance of 'IAC-17' to infestation. The genotypes 'IAC-PL1', 'IAC-19', 'Conquista', 'IAC-24' and 'IAC-17' extended the insect's life cycle, indicating the occurrence of a small degree of antibiosis and/or non-preference for feeding.Desde que se registró por primera vez en Brasil en la década de 1990, el biotipo B de la mosca-blanca (Bemisia tabaci Genn., Hemiptera: Aleyrodidae, se reconoce como una importante plaga de la soya (Glycine max L. y es lo que reduce la productividad de estas especies de leguminosas en algunas zonas del pais. Como una alternativa al control químico, el uso de genotipos resistentes representa una herramienta importante para la gestión integrada de plagas (MIP. Este trabajo evaluó el comportamiento de 10 genotipos de soya frente al ataque de la mosca-blanca, por medio de ensayos de atractividad y preferencia para ovipostura en invernaderos y antibiosis en laboratorio. En una prueba de elección multiple, 'IAC-17' fue el menos atractivo para los insectos. En una prueba sin elecci

  14. Antibiosis Contributes to Biological Control of Fire Blight by Pantoea agglomerans Strain Eh252 in Orchards.

    Science.gov (United States)

    Stockwell, V O; Johnson, K B; Sugar, D; Loper, J E

    2002-11-01

    the incidence of fire blight by 55 +/- 8%, 10:12 by 30 +/- 6%, streptomycin by 75 +/- 4%, and oxytetracycline by 16 +/- 14%. The effectiveness of strain 10:12 compared with water treatment indicates that other mechanisms (e.g., competitive exclusion or habitat modification) also contribute to disease suppression by P. agglomerans. The increased suppression of fire blight by the parental strain Eh252 compared with the antibiotic-deficient mutant 10:12 indicates that antibiosis is an important mechanism of biological control of fire blight. PMID:18944246

  15. In vitro growth inhibition of intra root canal pathogenic microorganisms by Lactic Acid Bacteria, an Antibiosis method

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    A. Nakhjavani F.

    2008-12-01

    Full Text Available "nBackground and Aim: Elimination of microorganisms and their byproducts from root canal system is one of important aims of root canal therapy. This object is gained by using of many chemomechanical techniques but with noncertain success. A new method is used of nonpathogenic bacteria for growth inhibition of pathogenic bacteria, Antibiosis, in root canal therapy.The aim of this study was in vitro evaluation of antimicrobial effect of probiotics, such as Lactic Acid Bacteria (LAB on the infected root canal bacteria. "nMaterials and Methods: Isolated bacteria from infected root canal were grown and then scattered onto the muller Hinton agar plates which contain wells, LAB, extracted from dairy products, were added into these wells, Inhibition effected of LAB was determined. Furthermore the sample taken from the inhibition zone and possible resistant monoclonal bacteria also were identified, then 6 sensitive and 14 resistant samples were selected and E. faecalis species were added to them; Then antimicrobial effects of LAB on these samples was reevaluated. "nResults: The results showed that 66.7% of the samples were sensitive at least to one type of LAB, and 33% were resistant to all kind of LAB. Meanwhile the outgrowing anaerobic bacteria inside the inhibition zone were from the low frequency oral bacterial flora. Furthermore, adding E. faecalis to the samples caused more sensitivity of them to LAB. Mc-Neamar test recognized the difference significant. "nConclusion: This study showed that the LAB inhibit growth of the pathogenic root canal bacteriae. Furthermore, presence of E. faecalis reinforces the antimicrobial effect of LAB. It seemed that LAB maybe have potential to use in endodontic practice for elimination of root canal infections.

  16. Folliculitis et perifolliculitis capitis abscedens et suffodiens controlled with a combination therapy: Systemic antibiosis (Metronidazole Plus Clindamycin, dermatosurgical approach, and high-dose isotretinoin

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    Georgi Tchernev

    2011-01-01

    Full Text Available Folliculitis et perifolliculitis capitis abscedens et suffodiens is a rare disease of unknown etiology. It is a suppurative process that involves the scalp, eventually resulting in extensive scarring and irreversible alopecia. The condition is also known as ′acne necrotica miliaris′ or ′Proprionibacterium′ folliculitis. Most often the disease affects men of African-American or African-Caribbean descent between 20 and 40 years of age. The clinical picture is determined by fluctuating painful fistule-forming conglomerates of abscesses in the region of the occipital scalp. The cause of scalp folliculitis is not well understood. It is generally considered to be an inflammatory reaction to components of the hair follicle, particularly the micro-organisms. These include: bacteria (especially Propionibacterium acnes, but in severe cases, also Staphylococcus aureus, Yeasts (Malassezia species and mites (Demodex folliculorum. The initial histopathologic finding is an exclusively neutrophilic infiltration followed by a granulomatous infiltrate. The treatment of the disease is usually difficult and often disappointing. Successful treatment with isotretinoin 1 mg/kg body mass could be achieved only after regular systematic administration in the course of 3-4 months. Here we describe a patient with eruptive purulent form of the disease, which has been controlled with combination therapy: systemic antibiosis with metronidazole and clindamycin, dermatosurgical removal of single nodular formations, and isotretinoin 1 mg/kg body mass for 3-5 months.

  17. Efecto rizosférico de Parmelia sp y Solanum lixioides sobre actinomicetos y ensayos de antibiosis in vitro Rhizozpheric effect of Parmelia sp and Solanum lixioides on actinomycetes and their in vitro antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Zárate Lyda

    1999-11-01

    Full Text Available

    La presencia de actinomicetos en muestras de suelo alrededor de raíces y rizoides de Parmelia sp y de Solanum lixioides fue investigado. 5e evaluó el efecto rizosférico del liquen Parmelia sp sobre poblaciones de actinomicetos con un R/5 ~ 2.5, mientras el radio R/5 resultante en S.lixioides fue <1. En los ensayos de antibiosis los mejores resultados se obtuvieron al modificar el medio de cultivo, o medio mínimo de Hopwood (1967, con relación a medio estándar. Se determinó el espectro de actividad antibiótica de 9 aislamientos, sobre organismos Gram positivos: Staphylococcus aureus, Bacillus subtilis y Gram negativos: Escherichia coli, Klebsiella pneumoniae y Pseudomonas aeruginosa. Los aislamientos A-2, A-4, A-5 YA-6 presentaron un amplio espectro de actividad antimicrobiana sobre E. coli, B. subtilis y K. pneumoniae. A-11, presentó una antibiosis selectiva y en grado alto sobre P. aeruginosa.

    The occurrence of actinomycetes from rhizospheric soils of Parmelia sp and Solanum lixioides was investigated. The rhizospheric effect from Parmelia sp (Lichen upon actinomycetes isolates was evaluated and was (R/5 ~ 2.5, while by the solanaceae the resultant ratio R/5 was <1. For the antibiosis assays the better results were obtained by moditying the culture médium (Hopwood minimun medium, 1967. The antimicrobial activity from nine isolates against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae; Pseudomonas aeruginosa was determined. A-2, A-4, A-S and A-6 isolates showed a broad spectrum of antimicrobial activity, while A-'Il showed a selective antimicrobial activity against P. aeruginosa.

  18. Expresión de la antibiosis y de la antixenosis contra el pulgón negro de los cereales (Sipha maydis) en cultivares comerciales de trigos

    OpenAIRE

    Saldúa, Vilma Luciana; Castro, Ana María

    2011-01-01

    Sipha maydis Passerini es una nueva plaga de cereales de invierno; su primera aparición en la Argentina ocurrió en el año 2002 expandiéndose rápidamente por todo el territorio infestando cereales y pastos. El presente trabajo tiene por objetivo analizar la antixenosis y la antibiosis de 47 cultivares comerciales de trigo frente a S. maydis. Se evaluó la antixenosis mediante la prueba de libre selección de hospedero contabilizando el número de áfidos por planta luego de 24 hs de infestación. L...

  19. Resistência por antibiose de Lycopersicon peruvianum à traça do tomateiro Antibiosis resistance of Lycopersicon peruvianum to tomato leafminer

    Directory of Open Access Journals (Sweden)

    Fábio Akiyoshi Suinaga

    2004-06-01

    Full Text Available Este trabalho foi realizado em casa de vegetação na Universidade Federal de Viçosa e objetivou estudar a resistência por antibiose do acesso CNPH 101 de Lycopersicon peruvianum a traça do tomateiro Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae e as possíveis causas químicas desta resistência. Os tratamentos foram as espécies de tomateiro Lycopersicon esculentum (cvs. IPA-5 e Santa Clara: padrões de suscetibilidade e o acesso de L. peruvianum. As características avaliadas foram: mortalidade larval, peso de pupas e proporção sexual, duração das fases larval e pupal e números de ovos/fêmea de T. absoluta. Realizou-se extração hexânica nas folhas e os extratos obtidos foram submetidos a cromatografia gasosa associada a espectrômetro de massa. O acesso CNPH 101 de L. peruvianum apresentou resistência a T. absoluta afetando a mortalidade larval e duração da fase pupal. Duas substâncias (provavelmente o 4-metil-2,6-di-tert-butilfenol e outra com tempo de retenção 18,8 min. no cromatograma estiveram associadas ao fato de que L. esculentum é mais suscetível a T. absoluta do que L. peruvianum. Foram detectadas duas substâncias associadas a plantas da cultivar Santa Clara (provavelmente o transcarofileno e de L. peruvianum (provavelmente o hexadecano mais suscetíveis a T. absoluta. Foi detectada uma substância (com tempo de retenção 22,796 min. no cromatograma associada a plantas de L. peruvianum mais resistentes a T. absoluta.This work was carried out in a greenhouse in the Federal University of Viçosa, to evaluate the antibiosis of Lycopersicon peruvianum (CNPH 101 to tomato leafminer Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae and its possible chemical causes. The treatments were represented by the species of tomato Lycopersicon esculentum (cv. Santa Clara and IPA-5: susceptibility patterns to T. absoluta and the introduction CNPH 101 of L. peruvianum. The characteristics assessed were: larval mortality, pupal

  20. Study on Anti-oxidation,Antibiosis and Blood Sugar Lowering of the Momordica Charantia Extracts%苦瓜提取液的抗氧化、抑菌和降血糖活性

    Institute of Scientific and Technical Information of China (English)

    傅明辉; 陈健汉; 庄东红

    2001-01-01

    This paper studied the anti - oxidation, antibiosis and blood sugar lowering of the extracts of the fruit flesh and seeds from Momordica charantia. It was found that the anti - oxidation activity of two extracts was very obvious. All three extracts could inhibit the growing of many kinds of common bacteria. The MIC of flesh of fruit was 1100 ~ 2500mg/ml and the MIC of seeds was 75 ~ 150mg/ml. All extracts had no obvious action on the lowering of blood sugar.%本文对苦瓜果肉及籽的提取液的抗氧化、抑菌和降血糖活性进行了探讨,发现苦瓜果肉及籽的提取液均具有明显的抗氧化活性,对常见多种细菌具有良好的抑制作用,其果肉MIC为1100~2500mg/ml,苦瓜籽的MIC为75~150mg/ml。提取液的降血糖活性并不明显。

  1. Tipos de resistência a Alabama argillacea (Huebner, 1818 (Lepidoptera: Noctuidae envolvidos em genótipos de algodoeiro: II. Antibiose Evaluation of cotton genotypes resistance to Alabama argillacea (Huebner, 1818 (Lepidoptera: Noctuidae: II. Antibiosis

    Directory of Open Access Journals (Sweden)

    ALVEMAR FERREIRA

    1999-01-01

    Full Text Available Objetivou-se verificar a ocorrência do tipo de resistência antibiose em genótipos de algodoeiro (Gossypium hirsutum L. em relação a Alabama argillacea (Huebner, 1818, em experimentos de laboratório (27 ± 2oC, 70 ± 10% de U.R. e fotofase de 14 horas. Folhas dos genótipos T 1122-13-1, STO 285 N, JPM 157, T 953-13-4-2, CNPA 9211-21 e CNPA 9211-31 foram fornecidas às larvas, diariamente, verificando-se a duração de cada fase do inseto, avaliando-se a massa de larvas aos 3 e aos 8 dias de idade, a massa de pupas e as porcentagens de mortalidade larval, pré-pupal e pupal. O delineamento utilizado foi inteiramente casualizado, com dez repetições, cada uma com dez larvas/genótipo. Em comparação com STO 285 N, todos os genótipos provocaram períodos mais longos de larva a adulto em A. argillacea; entretanto, os menores valores de massa de larvas com 3 dias e de massa média de pupas, e os maiores valores de duração do período larval e de mortalidade de larva a adulto foram verificados em CNPA 9211-31 e CNPA 9211-21, evidenciando que antibiose é um dos tipos de resistência presentes em ambos os genótipos.Cotton genotypes resistance to Alabama argillacea (Huebner, 1818 due to antibiosis has been evaluated in laboratory trials (at 27 ± 2oC, 70 ± 10% relative humidity and 14 hours photoperiod. Six different genetic materials (T 1122-13-1, STO 285 N, JPM 157, T 953-13-4-2, CNPA 9211-21, and CNPA 9211-31 have been tested in a completely randomized experimental design, with ten replications, each one with ten larvae/genotype. Larvae have been supplied with leaves daily. The following variables have been scored: time length of several insect stages (from larvae to adult, average mass of larvae and pupae as well as average larval, pre-pupal and pupal mortality rates. All genotypes have revealed longer overall average time length of stage duration from larvae to adult, as compared to STO 285 N; however, CNPA 9211-31 and CNPA 9211-21 have

  2. Antibiosis of the ferment of the endophyte Brevibacillus brevis strain 011%内生短短芽胞杆菌011菌发酵滤液抑菌活性研究

    Institute of Scientific and Technical Information of China (English)

    王宇婷; 易有金; 夏菠; 杨建奎; 曾静

    2013-01-01

    为明确短短芽胞杆菌011菌株在植物病害生物防治中的应用潜力,采用平皿打孔法测定011菌发酵滤液抗菌谱及其活性稳定性;采用孢子萌发法测定011菌发酵滤液对番茄早疫病菌最低抑菌浓度MIC及EC50;并显微观察其对番茄早疫病菌菌丝及孢子抑制作用.结果表明:011菌发酵滤液对8种植物病原真菌均有抑制作用,其中对番茄早疫病菌抑制作用较强,抑菌带宽度为5.5 mm;对番茄早疫病菌菌丝及孢子均有致畸作用;对番茄早疫病菌最低抑菌浓度MIC为30%,有效抑菌中浓度EC50为9.64%;其活性具有较好的热稳定性(100℃处理1h活性保持在95%0),耐酸性及抗紫外线(pH2.0处理及紫外20 W,30 cm照射120 min,活性保持不变).%To investigate the utilization potential of the strain 011 of Brevibacillus brevis in biocontrol of plant diseases,antibiosis spectrum and stability of its ferment were evaluated by plate-perforation method.MIC and EC50 of the ferment against Alternaria solani were determined by spore germination assay,and its inhibitive effects on both hyphae and spores of A.solani were validated by microscopy.The results suggested that the ferment of the strain 011 had an inhibitive effect on 8 fungal plant pathogens,and the strongest inhibition was observed in A.solani,with a 5.5 mm width of inhibition band.Moreover,the ferment had a teratogenic effect on both hyphae and spores of A.solani ; the MIC and EC50 were 30% and 9.64%,respectively; the ferment had considerable heat stability (with 95% bioactivity reserved after treatment at 100 ℃ for 1 h),acid tolerance and anti-UV property (bioactivity was unaffected by pre-treatment at pH2.0 or 20 W UV radiation from a distance of 30 cm for 120 min).

  3. Registration of two sugarcane germplasm clones with antibiosis to the sugarcane borer (Lepidoptera: Crambidae)

    Science.gov (United States)

    ‘Ho 08-9001’ and ‘Ho 08-9003’ germplasm were selected as early-generation clones (Saccharum x S. spontaneum) for the combined traits of resistance to the sugarcane borer (Diatraea saccharalis), vigorous growth habit, biomass yield, and high sucrose levels for a wide cross. Ho 08-9001 expressed 13% b...

  4. Role and prevalence of antibiosis and the related resistance genes in the environment

    DEFF Research Database (Denmark)

    Nazaret, Sylvie; Aminov, Rustam

    2014-01-01

    veterinary hospitals in the United Stated, and to the various environments of Continental Europe and Indochina. Besides, various genetic mechanisms and selection/co-selection factors contributing to the dissemination and maintenance of ARGs are presented. The topic is finalized by the mathematical modeling...... genes in the environment” in Frontiers in Microbiology: Antimicrobials, Resistance, and Chemotherapy presents the examples of occurrence and diversity of antibiotic resistance genes (ARGs) in the wide range of environments, from the grasslands of the Colombian Andes, to the dairy farms and small animal...

  5. Ancient host-pathogen associations maintained by specificity of chemotaxis and antibiosis.

    OpenAIRE

    Gerardo, Nicole M.; Jacobs, Sarah R.; Currie, Cameron R; Mueller, Ulrich G.

    2006-01-01

    Switching by parasites to novel hosts has profound effects on ecological and evolutionary disease dynamics. Switching requires that parasites are able to establish contact with novel hosts and to overcome host defenses. For most host–parasite associations, it is unclear as to what specific mechanisms prevent infection of novel hosts. Here, we show that parasitic fungal species in the genus Escovopsis, which attack and consume the fungi cultivated by fungus-growing ants, are attracted to their...

  6. Cross-Species GacA-Controlled Induction of Antibiosis in Pseudomonads▿

    OpenAIRE

    Dubuis, Christophe; Haas, Dieter

    2006-01-01

    Signal extracts prepared from culture supernatants of Pseudomonas fluorescens CHA0 and Pseudomonas aeruginosa PAO stimulated GacA-dependent expression of small RNAs and hence of antibiotic compounds in both hosts. Pseudomonas corrugata LMG2172 and P. fluorescens SBW25 also produced signal molecules stimulating GacA-controlled antibiotic synthesis in strain CHA0, illustrating a novel, N-acyl-homoserine lactone-independent type of interspecies communication.

  7. On the Function of Antibiosis of Honey Bees%浅析蜂蜜的抗菌作用

    Institute of Scientific and Technical Information of China (English)

    万金娥

    2015-01-01

    蜂蜜具有很强的抗菌作用,抗菌谱广泛。蜂蜜的抗菌作用既强又广,几乎对所有的菌类都有抑制或毁灭作用。%A honey bee is of an antibiotics with broad antibacterial spectrum,and it can Inhibit or destroy almost all kinds of bacteria.

  8. Antibiosis and dark-pigments secretion by the phytopathogenic and environmental fungal species after interaction in vitro with a Bacillus subtilis isolate

    Directory of Open Access Journals (Sweden)

    Alexandre Paulo Machado

    2010-10-01

    Full Text Available In this work, different reactions in vitro between an environmental bacterial isolate and fungal species were related. The Gram-positive bacteria had terminal and subterminal endospores, presented metabolic characteristics of mesophilic and acidophilic growth, halotolerance, positive to nitrate reduction and enzyme production, as caseinase and catalase. The analysis of partial sequences containing 400 to 700 bases of the 16S ribosomal RNA gene showed identity with the genus Bacillus. However, its identity as B. subtilis was confirmed after analyses of the rpoB, gyrA, and 16S rRNA near-full-length sequences. Strong inhibitory activity of environmental microorganisms, such as Penicillium sp, Aspergillus flavus, A. niger, and phytopathogens, such as Colletotrichum sp, Alternaria alternata, Fusarium solani and F. oxysporum f.sp vasinfectum, was shown on co-cultures with B. subtilis strain, particularly on Sabouraud dextrose agar (SDA and DNase media. Red and red-ochre color pigments, probably phaeomelanins, were secreted by A. alternata and A. niger respectively after seven days of co-culture.Na presente investigação, nosso objetivo principal foi relatar diferentes interações in vitro de um isolado bacteriano ambiental com espécies fúngicas. Através da identificação clássica, nós verificamos que o bacilo ambiental apresentava endósporos terminais e subterminais, características metabólicas de mesofilia, acidofilia, halotolerância, redução de nitrato e produção de enzimas, como caseinase e catalase. Análise de seqüências parciais do gene 16S RNAr contendo de 400 a 700 bases revelou identidade com gênero Bacillus. No entanto, a espécie Bacillus subtilis foi confirmada somente depois da análise de seqüências dos genes rpoB, gyrA, and 16S RNAr. Intensa atividade inibitória aos fungos ambientais, como Penicillium sp, Aspergillus flavus, A. niger, e fitopatogênicos, como Colletotrichum sp, Alternaria alternata, Fusarium solani e F. oxysporum f.sp vasinfectum, foi observada em coculturas com a cepa bacteriana (B. subtilis, particularmente em ágar Sabouraud dextrose e ágar DNase. Pigmentos de cor avermelhada e vermelho-amarronzado, provavelmente feomelaninas, foram secretados respectivamente por colônias de A. alternata e A. niger depois de sete dias de co-cultivo.

  9. Actividad nitrogenasa, producción de fitohormonas, sideróforos y antibiosis en cepas de Azospirillum y Klebsiella aisladas de maíz y teocintle

    OpenAIRE

    Moisés Graciano Carcaño-Montiel; Ronald Ferrera-Cerrato; Jesús Pérez-Moreno; José D. Molina-Galán; Yoav Bashan

    2006-01-01

    Las bacterias de los géneros Azospirillum y Klebsiella, conocidas como rizobacterias promotoras del crecimiento vegetal, son fijadoras de nitrógeno y productoras de sustancias reguladoras del crecimiento, por lo que ejercen un efecto benéfico en las plantas con las cuales interaccionan. Esta asociación microorganismo-planta puede mejorar el crecimiento de los cultivos a través de la combinación de fijación biológica de nitrógeno, producción de sustancias hormonales, incremento de la disponi...

  10. Influência da antibiose exercida por actinomicetos às estirpes de Bradyrhizobium SPP., na nodulação da soja Influence of antibiosis produced by actinomycetes on strains of Bradyrhizobium SPP. on soybean nodulation

    Directory of Open Access Journals (Sweden)

    João Carlos Pereira

    1999-01-01

    Full Text Available Este trabalho teve por objetivo avaliar o espectro antibiótico de actinomicetos provenientes de solos de Cerrados e a sua influência na nodulação da soja. As estirpes BR 29, BR 33, BR 40, BR 85, BR 86, BR 96, 47/587, 3B-7 e 4A-5 de Bradyrhizobium spp. apresentaram comportamento diferenciado em relação à resistência natural aos antibióticos produzidos por 204 actinomicetos. As estirpes BR 29 e BR 96 foram sensíveis a 5,2 e 9,9% dos antibióticos produzidos, respectivamente, enquanto a BR 33 apresentou sensibilidade a 20,3%. O antagonismo exercido pelos actinomicetos exclusivamente à BR 29 e BR 33 foi de 1,6 e 5,7%, respectivamente. Esse efeito não foi observado nas estirpes BR 40 e BR 96. Inoculações simples e em mistura das estirpes na presença de actinomicetos influenciaram a nodulação da soja. A co-inoculação da BR 33 e BR 29 com o isolado 370 reduziu o percentual de ocorrência média, nos nódulos, da BR 29, de 94,1% para 83,7%, com conseqüente aumento da BR 33 de 6,7% para 17,2%. Os resultados evidenciam a importância de estudos ecológicos desses microrganismos, visando avaliar o seu papel no estabelecimento de uma nodulação eficiente.The aim of this work was to evaluate the antibiotic spectrum of actinomycetes from Cerrado soils and their influence on soybean nodulation. Strains BR 29, BR 33, BR 40, BR 85, BR 86, BR 96, 47/587, 3B-7 and 4A-5 of Bradyrhizobium spp. were characterized by their natural resistence to antibiotics produced by 204 actinomycete isolates. The strains BR 29 and BR 96 of B. elkanii were sensitive to 5.2% and 9.9% the products of actinomycete isolates, respectively, while BR 33 was sensitive up to 20.3%. The antagonistic effects caused by actinomycete exclusively to BR 29 and BR 33 were 1.6% and 5.7% respectively. This effect was not observed for strains BR 40 and BR 96. Single and multistrains inoculations in the presence or absence of actinomycetes affected soybean nodulation. On double strain inoculations, with BR 33 and BR 29 mixed with actinomycete 370 there was a decrease in nodule occupancy by BR 29 from 94.1% to 83.7% with concomitant increase in the occupying of BR 33 from 6.7% to 17.2%. The results indicate the importance of ecological studies on actinomycetes population in order to access their role in the establishment of efficient nodulation.

  11. A Study of Combat Trauma Plaster (TMJ) Function on Antibiosis Activity of Common Pyogenic Bacteria%战创伤涂膜剂对常见化脓菌的抗菌活性研究

    Institute of Scientific and Technical Information of China (English)

    李仕英; 张海谱; 谭巨莲; 侯艳宁

    2012-01-01

    目的 测定战创伤涂膜剂对常见化脓菌的最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal concentration,MBC).方法 以培养基稀释战创伤涂膜剂、氯己定甲硝唑乳膏至不同浓度,分别加入化脓菌标准菌株大肠埃希菌、金黄色葡萄球菌、铜绿假单胞菌、奇异变形杆菌悬液,菌液浓度为105 cfu/ml,培养后观察细菌生长情况,确定两药的MIC和MBC并进行比较.结果 战创伤涂膜剂对大肠埃希菌、金黄色葡萄球菌、铜绿假单胞菌、奇异变形杆菌的MIC分别为0.0625 μg/ml、2 μg/ml、4μg/ml、8μg/ml,MBC分别为0.125 μg/ml、4 μg/ml、4 μg/ml、8 μg/ml.氯己定甲硝唑乳膏对大肠埃希菌、金黄色葡萄球菌、铜绿假单胞菌、奇异变形杆菌的MIC分别为1 μg/ml、8 μg/ml、> 32 μg/ml、>32 μg/ml,MBC分别为2μg/ml、16 μg/ml、> 32 μg/ml、> 32μg/ml.两药对金黄色葡萄球菌的杀菌率均达到99%以上.结论 战创伤涂膜剂对常见化脓菌有良好的抑菌、杀菌作用.%Objective To test the minimum inhibitory concentration (MIC) and minimum bactericidal concentration ( MBC) of combat trauma Plaster (TMJ) for war on common pyogenic bacteria. Methods TMJ and Metronidazole and Fenbuf-en Capsules were diluted to different concentrations with medium, then respectively added with the standard strains of pyogenic bacteria Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis suspension, and bacilli concentration was 105 cfu/ml, bacterial growth was observed after cultivation, and then the MIC and MBC of the two medicines were compared. Results The MIC of TMJ was escherichia coli 0.0625 μg/ml, staphylococcus aureus 2 μg/ml, Pseudomonas aeruginosa 4 μg/ml, Proteus mirabilis 8 μg/ml. The MBC of TMJ was Escherichia coli 0. 125 μg/ml, Staphylococcus aureus 4 μg/ml, Pseudomonas aeruginosa 4 μg/ml, Proteus mirabilis 8μg/ml. The MIC of Metronidazole and Fenbufen Capsules was escherichia coli 1 μg/ml, staphylococcus aureus 8 μg/ml, Pseudomonas aeruginosa >32 μg/ml, Proteus mirabilis >32 (jig/ml. The MBC of Metronidazole and Fenbufen Capsules was Escherichia coli 2 μg/ml, Staphylococcus aureus 16 μg/ml, Pseudomonas aeruginosa > 32 μg/ml, Proteus mirabilis > 32 μg/ml. Bactericidal coefficient rates of the two medicines for staphylococcus aureus were o-ver 99% . Conclusion TMJ can produce satisfactory bactericidal action on common pyogenic bacteria.

  12. Evaluación de la antibiosis a pulgón ruso Diuraphis noxia (Kurdjumov) en líneas recombinantes experimentales de trigo (Triticum aestivum L.)

    OpenAIRE

    Càrdenas, David

    2015-01-01

    El pulgón ruso del trigo (PRT), Diuraphis noxia (Kurdjumov) es una de las plagas más dañinas que atacan al cultivo de trigo y cebada, provocando pérdidas considerables en la producción. Este áfido ha evolucionado en numerosos biotipos existiendo al menos tres en Argentina, con características diferenciales a los de otras latitudes. Si bien se han identificado genes de resistencia biotipo-específicos, dentro del manejo integrado de plagas es crítico evaluar las fuentes de resistencia y los mat...

  13. Evaluation of properties of concrete using fluosilicate salts and metal (Ni,W) compounds

    Institute of Scientific and Technical Information of China (English)

    Gyu-Yong KIM; Eui-Bae LEE; Bae-Su KHIL; Seung-Hum LEE

    2009-01-01

    To improve watertightness and antibiosis of sewage structure concrete, the antimierobial watertight admixture was made with fluosilicate salts and antimicrobial compounds. And fresh properties, watertightness, harmlessness and antibiosis of concrete were investigated experimentally. As a result, the fresh properties of concrete were similar to those of an ordinary concrete, without setting time delay. Compressive strength and carbonation resistance of concrete were better than those of an ordinary concrete. Finally it was confirmed that the antimierobial watenight admixture of concrete had an antibiosis inhibiting SOB growth.

  14. Antibiotic Conditioned Growth Medium of Pseudomonas Aeruginosa

    Science.gov (United States)

    Benathen, Isaiah A.; Cazeau, Barbara; Joseph, Njeri

    2004-01-01

    A simple method to study the consequences of bacterial antibiosis after interspecific competition between microorganisms is presented. Common microorganisms are used as the test organisms and Pseudomonas aeruginosa are used as the source of the inhibitor agents.

  15. Periinterventional prophylactic antibiotics in radiological port catheter implantation; Periinterventionelle prophylaktische Antibiotikagabe bei der radiologischen Portkatheterimplantation

    Energy Technology Data Exchange (ETDEWEB)

    Gebauer, B.; Teichgraeber, U.; Werk, M. [Charite, Universitaetsmedizin Berlin (Germany). Klinik fuer Strahlenheilkunde; Wagner, H.J. [Vivantes Klinikum im Friedrichshain und am Urban (Germany). Inst. fuer Radiologie

    2007-08-15

    Purpose: To evaluate whether catheter-related infections after radiologically placed port catheters can be reduced by single-shot periinterventional antibiosis. Materials and Method: Between January and September 2002, 164 consecutive patients with indication for central venous port catheter implantation were included in the present study. During implantation the interventional radiologist was responsible for deciding whether to administer a prophylactic single-shot antibiosis. The prophylactic antibiosis entailed intravenous administration of ampicillin and sulbactam (3 g Unacid, Pfizer) or 100 mg ciprofloxacine (Ciprobay, Bayer) in the case of an allergy history to penicillins. Catheter-related infection was defined as a local or systemic infection necessitating port catheter extraction. Results: Indication for port catheter implantation was a malignant disease requiring chemotherapy in 158 cases. The port catheter (Chemosite [Tyco Healthcare] [n = 123], low-profile [Arrow International] [n = 35], other port system [n = 6]) was implanted via sonographically guided puncture of the right jugular vein in 139 patients, via the left jugular vein in 24 cases and via the right subclavian vein in one patient. 75 patients received periinterventional prophylactic antibiosis (Unacid [n = 63] Ciprobay [n = 12]) and 89 patients did not receive antibiosis. The prophylactic antibiosis caused a minor allergic reaction in one patient that improved with antihistamic and corticoid medication. A total of 7 ports, 6 without prophylactic antibiosis versus one with periinterventional prophylaxis, were extracted due to infectious complications. Conclusion: Single-shot periinterventional prophylactic antibiosis can reduce early and late infectious complications after radiological-interventional placement of central venous port catheters. (orig.)

  16. Resistance and susceptibility of alfalfa (Medicago sativa L.) cultivars to the aphid Therioaphis maculata (Homoptera:Aphididae): insect biology and cultivar evaluation

    Institute of Scientific and Technical Information of China (English)

    ALEXANDRE DE ALMEIDA E SILVA; ELENICE MOURO VARANDA; JOS(E) RICARDO BAROSELA

    2006-01-01

    Biology of the aphid Therioaphis maculata was studied on alfalfa (Medicago sativa L.), including four resistant (Mesa-Sirsa, CUF101, Baker and Lahontan) and two susceptible (ARC and Caliverde) alfalfa cultivars, and one of the most cropped Brazilian cultivars, Crioula. Under controlled conditions, antibiosis (i.e., reduced longevity, fecundity and increased mortality of the aphid) was observed mainly on the resistant alfalfa cultivars,except on Lahontan. Crioula seemed to be tolerant to aphids. Present data support geographic limitation usage of cultivars, and we suggest Baker and Mesa-Sirsa as sources of antibiosis,and provide biological information of a tropical T. maculata biotype on alfalfa.

  17. Physiological Activity of Bryophyta%苔藓植物的生理活性

    Institute of Scientific and Technical Information of China (English)

    朱秀敏

    2011-01-01

    Many kinds of pharmacological activities of bryophyta were introduced, such as antibiosis, anticancer and preventing and curing disease of cardiovascular system.%介绍了苔藓植物的多种药理活性,如抗菌、抗癌、防治心血管系统疾病等.

  18. Draft Genome Sequences of Pseudomonas fluorescens Strains PA4C2 and PA3G8 and Pseudomonas putida PA14H7, Three Biocontrol Bacteria against Dickeya Phytopathogens.

    Science.gov (United States)

    Cigna, Jérémy; Raoul des Essarts, Yannick; Mondy, Samuel; Hélias, Valérie; Beury-Cirou, Amélie; Faure, Denis

    2015-01-29

    Pseudomonas fluorescens strains PA4C2 and PA3G8 and Pseudomonas putida strain PA14H7 were isolated from potato rhizosphere and show an ability to inhibit the growth of Dickeya phytopathogens. Here, we report their draft genome sequences, which provide a basis for understanding the molecular mechanisms involved in antibiosis against Dickeya.

  19. Characterization of Rhizobacteria Associated with Weed Seedlings †

    OpenAIRE

    Kremer, Robert J.; Begonia, Maria Fatima T.; Stanley, Lynn; Lanham, Eric T.

    1990-01-01

    Rhizobacteria were isolated from seedlings of seven economically important weeds and characterized for potential phytopathogenicity, effects on seedling growth, and antibiosis to assess the possibility of developing deleterious rhizobacteria as biological control agents. The abundance and composition of rhizobacteria varied among the different weed species. For example, fluorescent pseudomonads represented from 11 to 42% of the total rhizobacterial populations from jimsonweed and lambsquarter...

  20. Characterization and genetic dissection of resistance to spotted alfalfa aphid (Therioaphis trifolii) in Medicago truncatula

    KAUST Repository

    Kamphuis, L. G.

    2013-09-21

    Aphids cause significant yield losses in agricultural crops worldwide. Medicago truncatula, a model legume, cultivated pasture species in Australia and close relative of alfalfa (Medicago sativa), was used to study the defence response against Therioaphis trifolii f. maculate [spotted alfalfa aphid (SAA)]. Aphid performance and plant damage were compared among three accessions. A20 is highly susceptible, A17 has moderate resistance, and Jester is strongly resistant. Subsequent analyses using A17 and A20, reciprocal F1s and an A17×A20 recombinant inbred line (RIL) population revealed that this moderate resistance is phloem mediated and involves antibiosis and tolerance but not antixenosis. Electrical penetration graph analysis also identified a novel waveform termed extended potential drop, which occurred following SAA infestation of M. truncatula. Genetic dissection using the RIL population revealed three quantitative trait loci on chromosomes 3, 6, and 7 involved in distinct modes of aphid defence including antibiosis and tolerance. An antibiosis locus resides on linkage group 3 (LG3) and is derived from A17, whereas a plant tolerance and antibiosis locus resides on LG6 and is derived from A20, which exhibits strong temporary tolerance. The loci identified reside in regions harbouring classical resistance genes, and introgression of these loci in current medic cultivars may help provide durable resistance to SAA, while elucidation of their molecular mechanisms may provide valuable insight into other aphid–plant interactions.

  1. Draft Genome Sequences of Pseudomonas fluorescens Strains PA4C2 and PA3G8 and Pseudomonas putida PA14H7, Three Biocontrol Bacteria against Dickeya Phytopathogens

    OpenAIRE

    Cigna, Jérémy; Raoul des Essarts, Yannick; Mondy, Samuel; Hélias, Valérie; Beury-Cirou, Amélie; Faure, Denis

    2015-01-01

    Pseudomonas fluorescens strains PA4C2 and PA3G8 and Pseudomonas putida strain PA14H7 were isolated from potato rhizosphere and show an ability to inhibit the growth of Dickeya phytopathogens. Here, we report their draft genome sequences, which provide a basis for understanding the molecular mechanisms involved in antibiosis against Dickeya.

  2. The multiple personalities of Streptomyces spp. from the rhizosphere of apple cultivated in brassica seed meal ameded soils

    Science.gov (United States)

    Brassicaceae seed meal soil amendments proved control of Rhizoctonia root rot, in part, through the proliferation of indigenous rhizosphere colonizing Streptomyces spp. Studies were conducted to assess the relative role of antibiosis and nitric oxide (NO) production in the capacity of Streptomyces ...

  3. Genome Sequence of the Plant Growth-Promoting Rhizobacterium Bacillus sp. Strain 916

    OpenAIRE

    Wang, Xiaoyu; Luo, Chuping; Chen, Zhiyi

    2012-01-01

    Bacillus sp. strain 916, isolated from the soil, showed strong activity against Rhizoctonia solani. Here, we present the high-quality draft genome sequence of Bacillus sp. strain 916. Its 3.9-Mb genome reveals a number of genes whose products are possibly involved in promotion of plant growth or antibiosis.

  4. Quantitative trait loci mapping of pubescence density and flowering time of insect-resistant soybean (Glycine max L. Merr.

    Directory of Open Access Journals (Sweden)

    Kunihiko Komatsu

    2007-01-01

    Full Text Available Analysis of antibiosis resistance to common cutworm (Spodoptera litura Fabricius in soybean (Glycine max (L. Merr. has progressed significantly, but the immediate cause remains unknown. We performed quantitative trait loci (QTL analysis of pubescence density and plant development stage because these factors are assumed to be the immediate cause of resistance to cutworm. The QTLs for pubescence appeared to be identical to the previously detected the Pd1 and Ps loci controlling pubescence density. We found no candidate loci for flowering time QTLs, although one could be identical to the gene governing the long-juvenile trait or to the E6 loci controlling maturity. None of the QTLs overlapped with the QTLs for antibiosis resistance.

  5. Some structures of marine natural products

    Energy Technology Data Exchange (ETDEWEB)

    Finer-Moore, J.S.

    1979-07-01

    Applications of x-ray crystallographic methods to marine chemistry are discussed. Results of research on a biosynthetic problem: diterpenes from Dictyotaceae are discussed under the following section headings: history of the problem; dictyoxepin; dictyodial; and dictyolactone. Studies on marine ecology are reported under the following headings: symbiosis and antibiosis; metabolites from opisthobranch molluscs, including, dolabelladiene, 9-isocyanopupukeanane and 2-isocyanopupukeanane, and crispatone; metabolites of goronians and soft corals, including zooxanthellae and the metabolism of coelenterates, ophirin, sinularene, and erectene. (JGB)

  6. Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.

    Science.gov (United States)

    González, Alex; Labrín, Natalia; Alvarez, Rosa M; Jayaro, Yorman; Gamboa, Carlos; Reyes, Edicta; Barrientos, Venancio

    2012-03-01

    Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata. PMID:22458212

  7. Postinfection Biological Control of Oomycete Pathogens of Pea by Burkholderia cepacia AMMDR1.

    Science.gov (United States)

    Heungens, K; Parke, J L

    2001-04-01

    ABSTRACT Burkholderia cepacia AMMDR1 is a biocontrol agent that reduces Pythium damping-off and Aphanomyces root rot severity on peas in the field. We studied the effect of B. cepacia AMMDR1 on post-infection stages in the life cycles of these pathogens, including mycelial colonization of the host, production of oogonia, and production of secondary zoospore inoculum. We used Burkholderia cepacia 1324, a seed and rootcolonizing but antibiosis-deficient Tn5 mutant of B. cepacia AMMDR1, to study mechanisms of biological control other than antibiosis. B. cepacia AMMDR1 significantly reduced Pythium aphanidermatum postinfection colonization and damping-off of pea seeds, even when the bacteria were applied 12 h after zoospore inoculation. B. cepacia AMMDR1 also significantly reduced colonization of taproots by Aphanomyces euteiches mycelium, but only when the bacteria were applied at high population densities at the site of zoospore inoculation. The antibiosisdeficient mutant, B. cepacia 1324, had no effect on mycelial colonization of seeds or roots by Pythium aphanidermatum nor A. euteiches, suggesting that antibiosis is the primary mechanism of biological control. B. cepacia AMMDR1, but not B. cepacia 1324, reduced production of A. euteiches oogonia. This effect occurred even when the population size of B. cepacia AMMDR1 was too small to cause a reduction in lesion length early on in the infection process and may result from in situ antibiotic production. B. cepacia AMMDR1 had no effect on the production of secondary zoospores of A. euteiches from infected roots. The main effects of B. cepacia AMMDR1 on postinfection stages in the life cycles of these pathogens therefore were reductions in mycelial colonization by Pythium aphanidermatum and in formation of oogonia by A. euteiches. No mechanism other than antibiosis could be identified. PMID:18943851

  8. Resistance of Wheat Accessions to the English Grain Aphid Sitobion avenae.

    Science.gov (United States)

    Hu, Xiang-Shun; Liu, Ying-Jie; Wang, Yu-Han; Wang, Zhe; Yu, Xin-Lin; Wang, Bo; Zhang, Gai-Sheng; Liu, Xiao-Feng; Hu, Zu-Qing; Zhao, Hui-Yan; Liu, Tong-Xian

    2016-01-01

    The English grain aphid, Sitobion avenae, is a major pest species of wheat crops; however, certain varieties may have stronger resistance to infestation than others. Here, we investigated 3 classical resistance mechanisms (antixenosis, antibiosis, and tolerance) by 14 wheat varieties/lines to S. avenae under laboratory and field conditions. Under laboratory conditions, alatae given the choice between 2 wheat varieties, strongly discriminated against certain varieties. Specifically, the 'Amigo' variety had the lowest palatability to S. avenae alatae of all varieties. 'Tm' (Triticum monococcum), 'Astron,' 'Xanthus,' 'Ww2730,' and 'Batis' varieties also had lower palatability than other varieties. Thus, these accessions may use antibiosis as the resistant mechanism. In contrast, under field conditions, there were no significant differences in the number of alatae detected on the 14 wheat varieties. One synthetic line (98-10-30, a cross between of Triticum aestivum (var. Chris) and Triticum turgidum (var. durum) hybridization) had low aphid numbers but high yield loss, indicating that it has high antibiosis, but poor tolerance. In comparison, 'Amigo,' 'Xiaoyan22,' and some '186Tm' samples had high aphid numbers but low yield loss rates, indicating they have low antibiosis, but good tolerance. Aphid population size and wheat yield loss rates greatly varied in different fields and years for '98-10-35,' 'Xiaoyan22,' 'Tp,' 'Tam200,' 'PI high,' and other '186Tm' samples, which were hybrid offspring of T. aestivum and wheat related species. Thus, these germplasm should be considered for use in future studies. Overall, S. avenae is best adapted to 'Xinong1376,' because it was the most palatable variety, with the greatest yield loss rates of all 14 wheat varieties. However, individual varieties/lines influenced aphid populations differently in different years. Therefore, we strongly recommend a combination of laboratory and long-term field experiments in targeted planting

  9. Search for endophytic diazotrophs in barley seeds

    Directory of Open Access Journals (Sweden)

    Myriam S. Zawoznik

    2014-06-01

    Full Text Available Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.

  10. Search for endophytic diazotrophs in barley seeds.

    Science.gov (United States)

    Zawoznik, Myriam S; Vázquez, Susana C; Díaz Herrera, Silvana M; Groppa, María D

    2014-01-01

    Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.

  11. Role of killer factors in the inhibitory activity of bio-control yeasts against Penicillium expansum and Aspergillus ochraceus

    OpenAIRE

    Ciro da Silva Portes; Andriélen Virke de Oliveira; Patrícia Simer; Alessandra Machado Lunkes; Alexandre Rodrigo Coelho

    2013-01-01

    This work evaluated the antagonism of killer positive yeast strains (isolated from 11 samples of different frozen fruit pulps) against the strains of Penicillium expansum and Aspergillus ochraceus. Of the total 41 killer yeasts tested in YM agar, 19 showed antibiosis against P. expansum and A. ochraceus, with inhibition zone ranging from 10 to 18 mm and 10 to 19 mm, respectively. In the following step, the extracellular activity of Kluyveromyces sp. FP4(13) was tested performing the assay in ...

  12. Gamma ({sup 60}CO) radiation effects on arcelin protein and evaluation of bean lineages against Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boh.) (Col.: Bruchidae);Efeito da radiacao gama ({sup 60}CO) sobre a proteina arcelina e avaliacao de linhagens de feijoeiro a Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boh.) (Col.: Bruchidae)

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Ana Claudia Girardo

    2006-07-01

    The resistance of arcelin carrying seeds of bean lineages (Phaseolus vulgaris L.) against the bean weevils Acanthoscelides obtectus (Say, 1831) and Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Bruchidae), and the influence of gamma radiation ({sup 60}CO) on the manifestation of arcelin resistance to Z. subfasciatus were verified. Laboratorial tests, in choice and non-choice tests, with wild specimens carrying Arc-1, Arc-2, Arc-3, Arc-4, Raz-56 and Raz-59 (with Arc-5 alleles) and commercial lineages as control IAC - Carioca and IAC - Arua were conducted. Statistical design was completely randomized, with five repetitions, with 10 g of grains from each lineage samples by portion. Attractiveness, oviposition, emergence, mortality, adults' weigh and longevity, developing period, sexual rate, seeds' weigh loss, infestation and fecundity (Z. subfasciatus) were observed. Gamma radiation doses irradiations, in general, haven't affected the resistance manifestation of lineages carrying arcelin protein variants against the Z. subfasciatus bean weevil, thus, joint application use of both control methods can be recommended. Raz-56 lineage showed high resistance of the antibiosis types and non-preference for oviposition and feeding to Z. subfasciatus, while Raz-59 showed antibiosis and non-preference for feeding, and both (Raz-56 and Raz-59) showed intermediate resistance to A. obtectus, against which lineage Arc-2 was the most harmful to its development, expressing non-preference to feeding and/or antibiosis. (author)

  13. Reduction in pathogen populations at grapevine wound sites is associated with the mechanism underlying the biological control of crown gall by rhizobium vitis strain ARK-1.

    Science.gov (United States)

    Kawaguchi, Akira

    2014-09-17

    A nonpathogenic strain of Rhizobium (=Agrobacterium) vitis, ARK-1, limited the development of grapevine crown gall. A co-inoculation with ARK-1 and the tumorigenic strain VAT07-1 at a 1:1 cell ratio resulted in a higher population of ARK-1 than VAT07-1 in shoots without tumors, but a significantly lower population of ARK-1 than VAT07-1 in grapevine shoots with tumors. ARK-1 began to significantly suppress the VAT07-1 population 2 d after the inoculation. This result indicated that ARK-1 reduced the pathogen population at the wound site through biological control. Although ARK-1 produced a zone of inhibition against other tumorigenic Rhizobium spp. in in vitro assays, antibiosis depended on the culture medium. ARK-1 did not inhibit the growth of tumorigenic R. radiobacter strain AtC1 in the antibiosis assay, but suppressed the AtC1-induced formation of tumors on grapevine shoots, suggesting that antibiosis by ARK-1 may not be the main mechanism responsible for biological control.

  14. Determination of the resistance types to Spodoptera cosmioides (Walker (Lepidoptera: Noctuidae in soybean genotypes

    Directory of Open Access Journals (Sweden)

    Arlindo Leal Boiça Júnior

    2015-04-01

    Full Text Available The aim of this work was to evaluate the resistance types in soybean genotypes to Spodoptera cosmioides (Walker in laboratory. Soybean genotypes assessed were as follows: ‘IAC 100’ (resistance standard, ‘BR16’ (susceptible standard, ‘Dowling’, PI 227687, PI 274454, ‘IGRA RA 626 RR’, PI 227682, ‘BRSGO 8360’, ‘IGRA RA 516 RR’ and ‘P 98Y11 RR’. Free-choice and no-choice feeding non-preference tests were done using two newly-hatched larvae per genotype or one third-instar larva per genotype in both tests. Larvae attractiveness was evaluated in different times, and at the end of the experiments the leaf area consumed was quantified. In the antibiosis test, newly-hatched larvae were individualized into Petri dishes, where leaflets of the genotypes were offered over the larval stage, and the following biological parameters were assessed: period and viability of larvae, pupae and overall (larvae + pupae, weight of larvae and pupae, sex ratio and adults longevity. Overall, in the feeding preference tests, significant differences were not found in leaf consumption among the genotypes. In the antibiosis assay, genotypes PI 227687, PI 227682 and ‘IAC 100’ caused 100% larval mortality and the lowest weight of larvae, ranging between 37.65 and 85.56 mg. All soybean genotypes evaluated do not exhibit feeding non-preference type resistance to S. cosmioides, and PI 227687, PI 227682 and ‘IAC 100’ highlighted for possessing antibiosis.

  15. Warm-Season (C4) Turfgrass Genotypes Resistant to Spittlebugs (Hemiptera: Cercopidae).

    Science.gov (United States)

    Gusmão, M R; Valério, J R; Matta, F P; Souza, F H D; Vigna, B B Z; Fávero, A P; Barioni, W; Inácio, G R

    2016-08-01

    Screening for resistance to insect pests is one of the early stages of grass breeding programs. Pasture spittlebugs are sap-sucking insects that potentially cause severe damage to turfgrasses, including the loss of functional quality and perenniallity. The Brazilian flora has a large number of grass species with wide morphological variability and adaptability to different soil and climate conditions that can potentially be used as lawns. However, no study has screened turfgrass genotypes for resistance to spittlebug attack. In this study, we evaluated the intra- and interspecific variability of 35 turfgrass genotypes in the genera Paspalum, Axonopus, and Zoysia for resistance to the pasture spittlebugs, Deois flavopicta (Stal) and Notozulia entreriana (Berg) (Hemiptera: Cercopidae), as measured by damage scores, densities of nymphs and adults, and level of antibiosis resistance. Genotypes were grouped into three groups using cluster analysis and principal component analysis: GroupI had genotypes associated with low damage scores and high density of adult spittlebugs; GroupII had genotypes with intermediate damage scores and low density of nymphs and adults; and GroupIII was formed by genotypes with high damage scores and high nymph density. Intra- and interspecific genotypic variability was related to antibiosis resistance and morphological variation among genotypes with some indicating nonpreference resistance and others indicating tolerance resistance. Our results indicate that besides antibiosis resistance studies, it is essential to evaluate the morphological variability of grass genotypes when screening for resistance to insects. Further studies are needed to elucidate the intraspecific variability of Paspalum notatum Flüggé genotypes for resistance to spittlebug attack. PMID:27329631

  16. Complications of the diabetic foot.

    Science.gov (United States)

    Kim, Paul J; Steinberg, John S

    2013-12-01

    The diabetic foot is at high risk for complications because of its role in ambulation. Peripheral neuropathy and peripheral vascular disease can lead to chronic foot ulcers, which are at high risk for infection, in part attributable to areas of high pressure caused by lack of tolerance of the soft tissue and bone and joint deformity. If left untreated, infection and ischemia lead to tissue death, culminating in amputation. Treatment strategies include antibiosis, topical therapies, offloading, debridement, and surgery. A multidisciplinary team approach is necessary in the prevention and treatment of complications of the diabetic foot.

  17. Aislamiento de secuencias de cisteín proteasas expresadas en la interacción Brachiaria-Salivazo

    OpenAIRE

    Roda Fornaguera Federico; Chaparro Alejandro

    2006-01-01

    El ataque del salivazo induce en genotipos resistentes de Brachiaria la transcripción de un mARN que codifica
    para una proteasa de la familia de las papainas. En tres genotipos del pasto, caracterizados por presentar
    diferentes grados de resistencia al insecto, se aislaron secuencias genómicas y cDNA de homólogos a este
    transcrito, candidato a mediador de la antibiosis. Estas secuencias conforman una familia génica en la cual
    habrían ocurrido recien...

  18. [Cervicofacial actinomycosis: two case reports].

    Science.gov (United States)

    Mettler, Simone; Brunner, Flavio; Lambrecht, J Thomas

    2009-01-01

    Infectious diseases transmitted by actinomycosis species cause severe destructive lesions. This rare and specific infection is mainly found in the orofacial regions. Causes of any hard tissue swelling in the jaw have, thus, to be assessed carefully. When actinomycosis is identified, a surgical intervention with curettement, draining and long-term antibiosis is required. The aim of the current article is to describe two clinical cases and to show the necessity of both, microbiological and histological laboratory diagnostics, to hedge the clinic diagnosis. PMID:19408527

  19. Antibiotic Production by Erwinia herbicola Eh1087: Its Role in Inhibition of Erwinia amylovora and Partial Characterization of Antibiotic Biosynthesis Genes

    OpenAIRE

    Kearns, L. P.; Mahanty, H K

    1998-01-01

    Mutants of Erwinia herbicola Eh1087 (Ant−), which did not produce antibiotic activity against Erwinia amylovora, the fire blight pathogen, were selected after TnphoA mutagenesis. In immature pear fruit Ant− mutants grew at the same rate as wild-type strain Eh1087 but did not suppress development of the disease caused by E. amylovora. These results indicated that antibiosis plays an important role in the suppression of disease by strain Eh1087. All of the Ant− mutations obtained were located i...

  20. Pantoea agglomerans Strain EH318 Produces Two Antibiotics That Inhibit Erwinia amylovora In Vitro

    OpenAIRE

    Wright, Sandra A. I.; Zumoff, Cathy H.; Schneider, Lois; Beer, Steven V.

    2001-01-01

    Pantoea agglomerans (synonym: Erwinia herbicola) strain Eh318 produces through antibiosis a complex zone of inhibited growth in an overlay seeded with Erwinia amylovora, the causal agent of fire blight. This zone is caused by two antibiotics, named pantocin A and B. Using a genomic library of Eh318, two cosmids, pCPP702 and pCPP704, were identified that conferred on Escherichia coli the ability to inhibit growth of E. amylovora. The two cosmids conferred different antibiotic activities on E. ...

  1. Near-isogenic lines of Triticum aestivum with distinct modes of resistance exhibit dissimilar transcriptional regulation during Diuraphis noxia feeding

    Directory of Open Access Journals (Sweden)

    Anna-Maria Botha

    2014-10-01

    Full Text Available Russian wheat aphid (Diuraphis noxia, Kurdjumov feeding on susceptible Triticum aestivum L. leads to leaf rolling, chlorosis and plant death – symptoms not present in resistant lines. Although the effects of several D. noxia (Dn resistance genes are known, none have been isolated or characterized. Wheat varieties expressing different Dn genes exhibit distinct modes of D. noxia resistance, such as antibiosis (Dn1, tolerance (Dn2, and antixenosis (Dn5. However, the mechanism whereby feeding aphids are perceived, and how subsequent transcriptional responses are partitioned into resistance categories, remains unclear. Here we report on downstream events in near-isogenic wheat lines containing different Dn genes after D. noxia biotype SA1 feeding. Transcripts involved in stress, signal transduction, photosynthesis, metabolism and gene regulation were differentially regulated during D. noxia feeding. Expression analyses using RT-qPCR and RNA hybridization, as well as enzyme activity profiling, provide evidence that the timing and intensity of pathways induced are critical in the development of particular modes of resistance. Pathways involved include the generation of kinase signalling cascades that lead to a sustained oxidative burst, and a hypersensitive response that is active during antibiosis. Tolerance is a passive resistance mechanism that acts through repair or de novo synthesis of photosystem proteins. Results further suggest that ethylene-mediated pathways are possibly involved in generating volatile compounds and cell wall fortification during the antixenosic response.

  2. Biological control of the cucurbit powdery mildew pathogen Podosphaera xanthii by means of the epiphytic fungus Pseudozyma aphidis and parasitism as a mode of action

    Directory of Open Access Journals (Sweden)

    Aviva eGafni

    2015-03-01

    Full Text Available Epiphytic yeasts, which colonize plant surfaces, may possess activity that can be harnessed to help plants defend themselves against various pathogens. Due to their unique characteristics, epiphytic yeasts belonging to the genus Pseudozyma hold great potential for use as biocontrol agents. We identified a unique, biologically active isolate of the epiphytic yeast Pseudozyma aphidis that is capable of inhibiting Botrytis cinerea via a dual mode of action, namely induced resistance and antibiosis. Here, we show that strain L12 of P. aphidis can reduce the severity of powdery mildew caused by Podosphaera xanthii on cucumber plants with an efficacy of 75%. Confocal and scanning electron microscopy analyses demonstrated P. aphidis proliferation on infected tissue and its production of long hyphae that parasitize the powdery mildew hyphae and spores as an ectoparasite. We also show that crude extract of P. aphidis metabolites can inhibit P. xanthii spore germination in planta. Our results suggest that in addition to its antibiosis mode of action, P. aphidis may also act as an ectoparasite on P. xanthii. These results indicate that P. aphidis strain L12 has the potential to control powdery mildew.

  3. Alternatives to Antibiotics in Animal Agriculture: An Ecoimmunological View

    Directory of Open Access Journals (Sweden)

    Yongming Sang

    2014-12-01

    Full Text Available Ecological immunology (or ecoimmunology is a new discipline in animal health and immunology that extends immunologists’ views into a natural context where animals and humans have co-evolved. Antibiotic resistance and tolerance (ART in bacteria are manifested in antibiosis-surviving subsets of resisters and persisters. ART has emerged though natural evolutionary consequences enriched by human nosocomial and agricultural practices, in particular, wide use of antibiotics that overwhelms other ecological and immunological interactions. Most previous reviews of antibiotic resistance focus on resisters but overlook persisters, although both are fundamental to bacteria survival through antibiosis. Here, we discuss resisters and persisters together to contrast the distinct ecological responses of persisters during antibiotic stress and propose different regimens to eradicate persisters. Our intention is not only to provide an ecoimmunological interpretation, but also to use an ecoimmunological system to categorize available alternatives and promote the discovery of prospective approaches to relieve ART problems within the general scope of improving animal health. Thus, we will categorize available alternatives to antibiotics and envision applications of ecoimmunological tenets to promote related studies in animal production.

  4. Reevaluating the conceptual framework for applied research on host-plant resistance

    Institute of Scientific and Technical Information of China (English)

    Michael J.Stout

    2013-01-01

    Applied research on host-plant resistance to arthropod pests has been guided over the past 60 years by a framework originally developed by Reginald Painter in his 1951 book,Insect Resistance in Crop Plants.Painter divided the "phenomena" of resistance into three "mechanisms," nonpreference (later renamed antixenosis),antibiosis,and tolerance.The weaknesses of this framework are discussed.In particular,this trichotomous framework does not encompass all known mechanisms of resistance,and the antixenosis and antibiosis categories are ambiguous and inseparable in practice.These features have perhaps led to a simplistic approach to understanding arthropod resistance in crop plants.A dichotomous scheme is proposed as a replacement,with a major division between resistance (plant traits that limit injury to the plant) and tolerance (plant traits that reduce amount of yield loss per unit injury),and the resistance category subdivided into constitutive/inducible and direct/indirect subcategories.The most important benefits of adopting this dichotomous scheme are to more closely align the basic and applied literatures on plant resistance and to encourage a more mechanistic approach to studying plant resistance in crop plants.A more mechanistic approach will be needed to develop novel approaches for integrating plant resistance into pest management programs.

  5. Zoospore homing and infection events: effects of the biocontrol bacterium Burkholderia cepacia AMMDR1 on two oomycete pathogens of pea (Pisum sativum L.).

    Science.gov (United States)

    Heungens, K; Parke, J L

    2000-12-01

    Burkholderia cepacia AMMDR1 is a biocontrol agent that protects pea and sweet corn seeds from Pythium damping-off in field experiments. The goal of this work was to understand the effect of B. cepacia AMMDR1 on Pythium aphanidermatum and Aphanomyces euteiches zoospore homing events and on infection of pea seeds or roots. In vitro, B. cepacia AMMDR1 caused zoospore lysis, prevented cyst germination, and inhibited germ tube growth of both oomycetes. B. cepacia AMMDR1 also reduced the attractiveness of seed exudates to Pythium zoospores to nondetectable levels. However, when present at high levels on seeds, B. cepacia AMMDR1 had little net effect on zoospore attraction, probably because it also enhanced seed exudation. Seed-applied B. cepacia AMMDR1 dramatically reduced the incidence of infection by Pythium zoospores in situ compared with an antibiosis-deficient Tn5 mutant strain. This mutant strain also decreased Pythium infection incidence to some extent, but only when the pathogen inoculum potential was low. B. cepacia AMMDR1 did not affect attraction of Aphanomyces zoospores or Aphanomyces root rot incidence. These results suggest that B. cepacia AMMDR1 controls P. aphanidermatum largely through antibiosis, but competition for zoospore-attracting compounds can contribute to the effect. Differences in suppression of Aphanomyces and Pythium are discussed in relation to differences in the ecology of the two pathogens. PMID:11097889

  6. Biological control of the cucurbit powdery mildew pathogen Podosphaera xanthii by means of the epiphytic fungus Pseudozyma aphidis and parasitism as a mode of action.

    Science.gov (United States)

    Gafni, Aviva; Calderon, Claudia E; Harris, Raviv; Buxdorf, Kobi; Dafa-Berger, Avis; Zeilinger-Reichert, Einat; Levy, Maggie

    2015-01-01

    Epiphytic yeasts, which colonize plant surfaces, may possess activity that can be harnessed to help plants defend themselves against various pathogens. Due to their unique characteristics, epiphytic yeasts belonging to the genus Pseudozyma hold great potential for use as biocontrol agents. We identified a unique, biologically active isolate of the epiphytic yeast Pseudozyma aphidis that is capable of inhibiting Botrytis cinerea via a dual mode of action, namely induced resistance and antibiosis. Here, we show that strain L12 of P. aphidis can reduce the severity of powdery mildew caused by Podosphaera xanthii on cucumber plants with an efficacy of 75%. Confocal and scanning electron microscopy analyses demonstrated P. aphidis proliferation on infected tissue and its production of long hyphae that parasitize the powdery mildew hyphae and spores as an ectoparasite. We also show that crude extract of P. aphidis metabolites can inhibit P. xanthii spore germination in planta. Our results suggest that in addition to its antibiosis as mode of action, P. aphidis may also act as an ectoparasite on P. xanthii. These results indicate that P. aphidis strain L12 has the potential to control powdery mildew. PMID:25814995

  7. Simultaneous Formation of a Self-Wrinkled Surface and Silver Nanoparticles on a Functional Photocuring Coating.

    Science.gov (United States)

    Lin, Hongbo; Wang, Yuanlong; Gan, Yanchang; Hou, Honghao; Yin, Jie; Jiang, Xuesong

    2015-11-01

    Bioinspired functional surface with micro/nanostructures are particularly attractive because of the potential for outstanding characteristics, such as self-cleaning, self-replenishing and antibiosis. Here, we presented a facile approach to fabricate a functional photocuring coating with both a self-wrinkling patterned surface and incorporated silver nanoparticles (Ag NPs). Fluorinated polymeric photoinitiator (FPPI) and silver precursor (TFAAg) can self-assemble together on the air/acrylate interface to form a top layer of photocuring liquid resin. Under UV irradiation, a wrinkled pattern was formed as a result of the mismatch in shrinkage caused by photopolymerization between the top layer and the bulk layer. Simultaneously, Ag NPs with sizes of 15 ± 8 nm in diameter were in situ generated in the photocuring coating through the photoreduction of TFAAg. Their number density is higher in the top layer than in the bulk. Scanning electron microscope (SEM) and atomic force microscope (AFM) measurements revealed that the characteristic wavelength (λ) and amplitude (A) of the wrinkled morphology increased with growing concentration of FPPI, and that the generation of Ag NPs led to the wrinkle-to-fold transition. Furthermore, the obtained functional coatings possess a low surface energy and self-replenishing and antibiosis capabilities as a result of the synergistic effect of the wrinkled surface covered by FPPI and Ag NPs. PMID:26471347

  8. Research on the antibacterial activity of substances extracted from Tibet Kefir%西藏开菲尔中抑菌活性物质的提取及抑菌效果研究

    Institute of Scientific and Technical Information of China (English)

    黄曼曼; 陈雪香; 肖苏尧; 林健辉; 黄伟华; 曹庸

    2011-01-01

    采用水提取西藏开菲尔(Kefir)中的抑菌活性成分,用K—B纸片法测定提取物对常见的革兰氏阳性和革兰氏阴性细菌、部分真菌和霉菌的抑菌活性,并检测了用不同的pH、温度、光照处理后提取物的抑菌效果。研究结果表明,Kefir提取物对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌、黄曲霉和啤酒酵母均有明显的抑制效果,最小抑菌浓度(MIC)在6.25~12.5mg/mL之间,与尼生素相比,抑菌效果相当,抑菌谱更广;提取物在酸性和中性条件下抑菌活性稳定.而在碱性条件下抑菌活性减弱,且具有较好的热稳定性和光稳定性。%Active constituents in Kefir were extracted by water,the antibiosis activity on Escherichia coil, Staphylococcus aureus Rosen Bach,Bacillus subtilis,Shigella dysenteries,Sac-charomyces cerevisiae and Aflatoxin was studied by K-B slips. The extracts were treated with different pH,temperature,lights,then bacteriostasis was studied. The results showed that extracted antibacterial substance had shown antibiosis on Gram positive bacteria and Gram negative bacteria and parts of epiphyte. The minimum fungicide concentration of extracts was 6.25-12.5mg/mL. Compared with nisin,the antibiosis activity was limited,and more organisms spectrum. Antibacterial substance had good stability to hot, acidity and light.

  9. Evaluación de la resistencia a Schizaphis graminum (Hemiptera: Aphididae en cebada Assessment of resistance against Schizaphis graminum (Hemiptera: Aphididae in barley

    Directory of Open Access Journals (Sweden)

    Erica F. Tocho

    2012-06-01

    Full Text Available El pulgón verde de los cereales, Schizaphis graminum (Rondani, es una de las principales plagas de estos cultivos en el mundo y también presente en Argentina. Si bien el control químico es la práctica más utilizada, el uso de variedades resistentes (uno de los componentes principales del MIP es la estrategia más efectiva y ambientalmente más amigable para el control de plagas. Dado que las plantas presentan distintos mecanismos que les permiten defenderse de los insectos, el objetivo de este trabajo fue caracterizar la resistencia a Schizaphis graminum en una población de líneas recombinantes de cebada, e identificar aquellas con mejores características, portadoras de genes de resistencia a este insecto. La antixenosis fue analizada por la prueba de libre selección de hospederos. La antibiosis se evaluó por los parámetros del ciclo y el desarrollo del áfido y la tolerancia por características de crecimiento de las plantas bajo infestación. Al menos ocho líneas antibióticas fueron más tolerantes que sus testigos, presentando similares pesos secos, área foliar y contenido de clorofila bajo infestación. Estas líneas portadoras de genes de resistencia pueden ser de utilidad en los planes de mejora de la cebada.Greenbug, Schizaphis graminum (Rondani is one of the major pests of cereals around the world that is present in Argentina. Chemical control is the most widely used practice; however, the use of resistant varieties, one of the main components in IPM, is the most effective and environmentally sustainable strategy of control. Since plants have different types of insect resistance that allow them to defend against pests, the aim of the current study was to characterize the resistance to Schizaphis graminum in a population of recombinant inbred lines of barley and to identify lines with improved characteristics that enable the development of commercial cultivars. Antixenosis was studied by the host free choice test. Antibiosis

  10. Potencial de pseudomonas spp. fluorescentes para biocontrole de alternaria ricini em mamoneira Potential of fluorescent pseudomonas spp. For biological control of alternaria ricini on castorbean

    Directory of Open Access Journals (Sweden)

    Francisco de A.G. da Silva

    1998-06-01

    Full Text Available The potential of fluorescent Pseudomonas spp. to control Alternaria leaf spot on castorbean, caused by Alternaria ricini, was studied under greenhouse conditions. Two periods for antagonist applications were tested: 48h before and simultaneously to the pathogen inoculation. Among the antagonists tested JA4 and BJ22 were the most effectives showing disease severity reduction of 20.9% and 17.8% respectively, when applied simultaneously. The effect of Pseudomonas spp. on the micelial growth and sporulation was also studied throughout three different methods (funel, streak and celophane. Inhibition of micelial growth and sporulation was observed. There was no correlation between in vitro and in vivo data. Antibiosis was showed as a mode of action for Pseudomonas spp. in relation to Alternaria ricini. Ultrastructural studies confirmed the inhibition of spore germination by the bacteria.

  11. Identification of Soybean Resources of Resistance to Aphids

    Institute of Scientific and Technical Information of China (English)

    WU Tian-long; MA Xiao-hong; YAO Lu-ming; WANG Biao

    2009-01-01

    Four soybean [Glycine max (L.) Merr.] cultivars with soybean aphid resistance (Aphis glycines Matsmura), P189, P203, P574,and P746, were identified in field test, choice test, and non-choice test. The grade of resistance to aphids and the damage index of P189, P203, and P746 were significantly different from the susceptible cultivars (P=0.05). P574 and P746 showed antibiosis resistance, preventing aphids from reproducing on the plants. P203 showed antixenosis resistance, preventing aphids from reproducing in field test and choice test, but susceptible in non-choice test. Population development on plants was significantly different in field test, choice test, and non-choice test, which was caused by different selective pressures.

  12. Research progress in biological activities of pomegranate peel polyphenol%石榴皮多酚生物学活性的研究进展

    Institute of Scientific and Technical Information of China (English)

    马倩倩; 李建科; 于振; 赵伟; 黄瑞蕊; 张雅丽

    2013-01-01

    石榴皮多酚是石榴中重要的生理活性成分,具有抗氧化、抗癌、抗菌、降血脂等多种生物学功能,因而成为研究的热点.文章结合近年来有关石榴皮多酚研究成果,阐述了石榴皮多酚生物学活性及展望.%As important active components of pomegranate, pomegranate peel polyphenols have intrigued researchers for their biological activities such as anti - oxidation, anticancer, antibiosis, cholesterol-lowering effects and so on. Combined with the research results in recent years,the biological acivities of pomegranate peel polyphenols and prospects were reviewed in this paper.

  13. Acute pulmonary edema following liposuction due to heart failure and atypical pneumonia.

    Science.gov (United States)

    Wollina, Uwe; Graf, Andreas; Hanisch, Volkmar

    2015-05-01

    Microcannular liposuction in tumescent anesthesia is the most effective treatment for painful lipedema. Tumescent anesthesia is an established and safe procedure in local analgesia when performed according to guidelines. Major adverse effects are rare. In patients with advanced lipedema, however, the commonly presented comorbidities bear additional risks.We report on post-surgical acute pulmonary edema after tumescent liposuction according to guidelines in a 52-year-old female patient with lipedema of the legs. We discuss in detail possible scenarios that might be involved in such emergency. In the present case the most likely was a retarded community acquired atypical pneumonia with aggravation of pre-existent comorbidities.A combined treatment with intravenous b-lactam antibiosis, positive pressure ventilation, and continuous venovenous hemodialysis and filtration resulted in complete remission in a couple of days. In conclusion, tumescent liposuction of advanced lipedema patients should only be performed in well-trained centers with sufficient infrastructure.

  14. Characterization of cowpea genotype resistance to Callosobruchus maculatus

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    Maria de Jesus Passos de Castro

    2013-09-01

    Full Text Available The objective of this work was to characterize the resistance of 50 cowpea (Vigna unguiculata genotypes to Callosobruchus maculatus. A completely randomized design with five replicates per treatment (genotype was used. No-choice tests were performed using the 50 cowpea genotypes to evaluate the preference for oviposition and the development of the weevil. The genotypes IT85 F-2687, MN05-841 B-49, MNC99-508-1, MNC99-510-8, TVu 1593, Canapuzinho-1-2, and Sanzi Sambili show non-preference-type resistance (oviposition and feeding. IT81 D-1045 Ereto and IT81 D-1045 Enramador exhibit antibiosis against C. maculatus and descend from resistant genitors, which grants them potential to be used in future crossings to obtain cowpea varieties with higher levels of resistance.

  15. 悬钩子属植物化学成分及药理活性研究进展%Progress of Chemical Constituents and Pharmacology of Genus Rubus

    Institute of Scientific and Technical Information of China (English)

    孟祥娟; 刘斌; 热增才旦; 折改梅; 姜艳艳

    2011-01-01

    The chemical constituents and pharmacology of Rubus in the latest 10 years were summarized to supply the scientific basis for further exploitation of Rubus. Flavonoids, terpenoids, tannins and steroids are the main constituents of Rubus. It has wide range of pharmacological effects including antibiosis,aiitiinflammatory,antitumor,antioxidant,anti-allergic, hepatoprotective and antinociceptive.%本文对近10年来悬钩子属植物的化学成分和药理活性研究进行了综述,为该属植物的进一步开发利用提供参考.悬钩子属植物的化学成分主要包括黄酮、萜、鞣质、甾等.药理活性主要包括抗菌、抗炎、抗肿瘤、抗氧化、抗过敏、保肝、镇痛等.

  16. Screening of antagonistic activity of microorganisms against Colletotrichum acutatum and Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    Živković Svetlana

    2010-01-01

    Full Text Available The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops. The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates. The two Streptomyces species exhibited the strongest antagonism against isolates of C. acutatum and C. gloeosporioides. Microscopic examination showed that the most common mode of action was antibiosis. The results of this study identify T. harzianum, G. roseum, B. subtilis, S. natalensis and S. noursei as promising biological control agents for further testing against anthracnose disease in fruits. .

  17. Antagonistic action of Lactobacillus spp. against Staphylococcus aureus in cheese from Mompox - Colombia

    Directory of Open Access Journals (Sweden)

    Piedad M. Montero Castillo

    2015-06-01

    Full Text Available In the food industry, food preservation techniquesthat do not use chemical products are becoming more common.Therefore, the aim of this research was to evaluate the antagonisticactivity (antibiosis of lactic-acid bacterial strains againstpathogenic microorganisms. Lactic-acid bacterial strains wereisolated from layered cheese and a commercial product (yogurt;and the same was done with pathogenic bacteria solely fromlayered cheese. The lactic-acid bacterial strains were identified asspecies from the Lactobacilli family, while the pathogenic bacteriafrom layered cheese were identified as Micrococcaceae familyspecies (Staphylococcus aureus. Subsequently, in the sameculture medium, bacteria of each species were sowed in order todetermine the inhibitory activity ability of the Lactic Acid Bacteria(BAL As a result, the highly antagonistic activity of the Lactobacilli(inhibition halos were larger than 0.5 centimeters in diameteragainst isolated pathogenic microorganisms was demonstrated.

  18. Controlled synthesis and photocatalysis of sea urchin-like Fe3O4@TiO2@Ag nanocomposites

    Science.gov (United States)

    Zhao, Yilin; Tao, Chengran; Xiao, Gang; Wei, Guipeng; Li, Linghui; Liu, Changxia; Su, Haijia

    2016-02-01

    Based on the synergistic photocatalytic activities of nano-sized TiO2 and Ag, as well as the magnetic properties of Fe3O4, a sea urchin-like Fe3O4@TiO2@Ag nanocomposite (Fe3O4@TiO2@Ag NCs) is controllably synthesized with tunable cavity size, adjustable shell layer of TiO2 nanofiber, higher structural stability and larger specific surface area. Here, Fe3O4@TiO2@Ag NCs are obtained with Fe3O4 as the core and nanofiber TiO2/Fe3O4/Ag nanoheterojunctions as the shell; and Ag nanoparticles with diameter of approximately 4 nm are loaded both on TiO2 nanofibers and inside the cavities of sea urchin-like Fe3O4@TiO2 nanocomposites uniformly. Ag nanoparticles lead to the production of more photogenerated charges in the TiO2/Fe3O4/Ag heterojunction via LSPR absorption, and enhance the band-gap absorption of TiO2, while the Fe3O4 cocatalyst provides the active sites for oxygen reduction by the effective transfer of photogenerated electrons to oxygen. So the photocatalytic performance is improved due to the synergistic effect of TiO2/Fe3O4/Ag nanoheterojunctions. As photocatalysts under UV and visible irradiation, the as-synthesized nanocomposites display enhanced photocatalytic and recycling properties for the degradation of ampicillin. Moreover, they present better broad-spectrum antibiosis under visible irradiation. The enhanced photocatalytic activity and excellent chemical stability, in combination with the magnetic recyclability, makes this multifunctional nanostructure a promising candidate for antibiosis and remediation in aquatic environmental contamination in the future.Based on the synergistic photocatalytic activities of nano-sized TiO2 and Ag, as well as the magnetic properties of Fe3O4, a sea urchin-like Fe3O4@TiO2@Ag nanocomposite (Fe3O4@TiO2@Ag NCs) is controllably synthesized with tunable cavity size, adjustable shell layer of TiO2 nanofiber, higher structural stability and larger specific surface area. Here, Fe3O4@TiO2@Ag NCs are obtained with Fe3O4 as the

  19. Categorizing sugarcane cultivar resistance to the sugarcane aphid and yellow sugarcane aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Akbar, W; Showler, A T; Reagan, T E; White, W H

    2010-08-01

    Sugarcane (Saccharum spp.) in Louisiana is colonized by two aphid species, the sugarcane aphid, Melanaphis sacchari (Zehntner), and the yellow sugarcane aphid, Sipha flava (Forbes) (Hemiptera: Aphididae). The main problem associated with M. sacchari is transmission of sugarcane yellow leaf virus, a casual agent of yellow leaf disease whose absence has been added to certification standards for micropropagated sugarcane in Louisiana. Greenhouse studies were conducted to categorize dominant commercial sugarcane cultivars for their ability to tolerate aphid injury and to express antixenotic or antibiotic effects on both aphid species. Antixenosis tests showed no preference among cultivars by either aphid species. Loss of chlorophyll content in tolerance tests also did not show differences among cultivars for both aphid species. However, antibiosis tests revealed that life history parameters such as the duration of the reproductive period and fecundity of both aphid species were negatively affected on 'HoCP 91-555' compared with 'L 97-128'. Estimation of demographic statistics indicated that both aphid species exhibited a significantly lower intrinsic rate of increase (1.8-2.8-fold) and longer doubling time (1.7-3.1-fold) on HoCP 91-555 relative to L 97-128. From these tests, cultivars in the current study can be ranked from most to the least susceptible as L 97-128 > 'LCP 85-384' > 'HoCP 96-540' > 'Ho 95-988' > HoCP 91-555 for M. sacchari and L 97-128 > LCP 85-384 > HoCP 91-555 for S. flava. Therefore, antibiosis is an important category of resistance in sugarcane to both aphid species, and HoCP 91-555 might provide useful germplasm for developing aphid resistant cultivars. PMID:20857758

  20. Resistance of wheat lines to Rhopalosiphum padi (Hemiptera: Aphididae) under laboratory conditions.

    Science.gov (United States)

    Razmjou, J; Mohamadi, P; Golizadeh, A; Hasanpour, M; Naseri, B

    2012-04-01

    Bird cherry-oat aphid, Rhopalosiphum padi (L.), a polyphagous species with a nearly worldwide distribution, is an important pest of wheat as well as the main vector of barley yellow dwarf virus. We evaluated the resistance categories of eight wheat lines including antibiosis, antixenosis, and tolerance against R. padi under laboratory conditions. The wheat lines tested were ERWYT 88-8, ERWYT 87-6, and ERWYT 87-4 (resistant); ERWYT 87-1, ERWYT 87-20, and ERWYT 88-11 (susceptible); ERWYT 88-12 and ERWYT 88-13 (intermediate). In the antibiosis experiment, R. padi produced fewest progeny on ERWYT 88-8, ERWYT 87-6, and ERWYT 87-4 in reproduction period. In the antixenosis test, R. padi performed best on ERWYT 87-1, ERWYT 87-20, and ERWYT 88-11. Fewer apterous aphids selected ERWYT 88-8, ERWYT 87-4, and ERWYT 87-6 lines indicating antixenosis of these lines to R. padi. In tolerance experiments, however growth parameters differed between treated and untreated seedlings of wheat lines with 10 aphids per day infestation during 21-d period, but not among eight wheat lines. The plant resistance index values were greatest for ERWYT 88-8 (9.71), followed by ERWYT 87-4 (7.04) and ERWYT 87-6 (4.76). ERWYT 88-8, ERWYT 87-6, and ERWYT 87-4 may be important sources of R. padi resistance for small grain breeding and integrated pest management programs. PMID:22606831

  1. Aislamiento de microorganismos para control biológico de Moniliophthora roreri

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    Liliana Yanet Suárez Contreras

    2013-12-01

    Full Text Available Moniliophthora roreri es un hongo que causa la moniliasis, una enfermedad de la mazorca en el cultivo de cacao (Theobroma cacao, con pérdidas hasta del 60% de la cosecha. El control biológico utilizando microorganismos endófitos surge como una alternativa para el manejo de esta enfermedad. En la presente investigación se evaluaron microorganismos con potencial para control biológico de M. roreri en Norte de Santander, Colombia. Para el efecto, se aisló e identificó este fitopatógeno y se utilizaron protocolos de desinfección de los posibles microorganismos antagonistas con siembras por diluciones seriadas, selección de los géneros microbianos con mayor potencial antagónico y evaluación de las cepas por la prueba de plato dual para evaluar el efecto biocontrolador de los hongos y la antibiosis para bacterias. Se tomaron muestras en los municipios de Cúcuta, Sardinata, El Tarra, Tibú y El Zulia, de las cuales se aislaron 17 cepas del fitopatógeno y 20 entre hongos y bacterias. De éstas se seleccionaron cuatro cepas de hongos y tres de bacterias por su capacidad antagónica contra M. roreri. Los mejores porcentajes de inhibición de crecimiento radial (PICR se alcanzaron con Paecilomyces sp. (HC002 vs M. roreri, con una media de 80.72%, seguido del tratamiento con Paecilomyces sp. (HZ002 vs M. roreri con 79.45%. Se demostró que el hongo Paecilomyces sp. también tiene un alto potencial antagónico in vitro frente a M. roreri. Al evaluar la antibiosis de las bacterias aisladas, se encontró que Bacillus brevis (BZ005 fue la más efectiva en todos los sitios del estudio, con porcentajes superiores a 89%.

  2. Identification and characterization of resistance to cowpea aphid (Aphis craccivora Koch in Medicago truncatula

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    Kamphuis Lars G

    2012-07-01

    Full Text Available Abstract Background Cowpea aphid (CPA; Aphis craccivora is the most important insect pest of cowpea and also causes significant yield losses in other legume crops including alfalfa, beans, chickpea, lentils, lupins and peanuts. In many of these crops there is no natural genetic resistance to this sap-sucking insect or resistance genes have been overcome by newly emerged CPA biotypes. Results In this study, we screened a subset of the Medicago truncatula core collection of the South Australian Research and Development Institute (SARDI and identified strong resistance to CPA in a M. truncatula accession SA30199, compared to all other M. truncatula accessions tested. The biology of resistance to CPA in SA30199 plants was characterised compared to the highly susceptible accession Borung and showed that resistance occurred at the level of the phloem, required an intact plant and involved a combination of antixenosis and antibiosis. Quantitative trait loci (QTL analysis using a F2 population (n = 150 from a cross between SA30199 and Borung revealed that resistance to CPA is controlled in part by a major quantitative trait locus (QTL on chromosome 2, explaining 39% of the antibiosis resistance. Conclusions The identification of strong CPA resistance in M. truncatula allows for the identification of key regulators and genes important in this model legume to give effective CPA resistance that may have relevance for other legume crops. The identified locus will also facilitate marker assisted breeding of M. truncatula for increased resistance to CPA and potentially other closely related Medicago species such as alfalfa.

  3. Genetic divergence of bean genotypes to infestation of Zabrotes subfasciatus (Bohemann (Coleoptera: Bruchidae

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    Eduardo Neves Costa

    2013-12-01

    Full Text Available The aim of this work was to evaluate the genetics divergence of bean genotypes in relation to the oviposition, feeding and development of Zabrotes subfasciatus, determining the degrees of resistance to the weevil. The genotypes used were: IAC Carioca-Tybatã, IAC Fortaleza, IAPAR 81, IAC Carioca-Eté, IAC Galante, IAC Harmonia, IAC Una, IAC Diplomata, BRS Supremo and RAZ 49. Tests were performed in laboratory under controlled humidity, temperature and photophase conditions. In free choice test, 10 g of bean genotypes seeds were distributed in circular openings placed equidistant from each other in aluminum trays, where 70 couples were released. The attractiveness was evaluated 24 hours and seven days after the experiment started, and then the number of eggs was evaluated. In non choice test, 10 g of seeds were used where seven couples of Z. subfasciatus, 24 hours-old, were released, remaining seven days, and after the adults retreat, the total number eggs, viable and unviable eggs, the number and percentage of emerged adults, weight, longevity and period from egg to adult of males and females, sex ratio, dry mass and dry mass consumed by insect were evaluated. In the genotype IAC Harmonia was observed the lower oviposition; RAZ 49 was the most non preference-type resistant for feeding and/or antibiosis-type resistant; BRS Supremo, IAC Carioca-Eté and IAPAR 81 are no preference for feeding and/or antibiosis-type moderate resistant; IAC Galante is susceptible and the other genotypes are highly susceptible to Z. subfasciatus

  4. Distinct roles of T-cell lymphopenia and the microbial flora for gastrointestinal and CNS autoimmunity.

    Science.gov (United States)

    Fischer, Henrike J; Witte, Ann-Kathrin; Walter, Lutz; Gröne, Hermann-Josef; van den Brandt, Jens; Reichardt, Holger M

    2016-05-01

    T-cell lymphopenia is a major risk factor for autoimmunity. Here we describe congenic Lewis (LEW) rats with a loss-of-function mutation in the Gimap5 gene, leading to a 92% reduction in peripheral T-cell numbers. Gimap5-deficient LEW rats developed eosinophilic autoimmune gastroenteritis accompanied by a 40-fold increase in IgE serum levels. This phenotype was ameliorated by antibiotic treatment, indicating a critical role of the microbial flora in the development of inflammatory bowel disease. Interestingly, Gimap5-deficient LEW rats showed strongly aggravated experimental autoimmune encephalomyelitis (EAE) after immunization with guinea pig myelin basic protein. This phenotype, however, persisted after antibiosis, confirming that the enhanced CNS autoimmune response in T-cell lymphopenic Gimap5-deficient LEW rats was unrelated to the composition of the microbial flora. Rather, it seems that it was caused by the 7-fold increase in the percentage of activated T cells producing IL-17 and IFN-γ, and the skewed T-cell receptor (TCR) repertoire, both of which were the result of T-cell lymphopenia and not affected by antibiosis. This notion was supported by the observation that adoptive T-cell transfer corrected the TCR repertoire and improved EAE. Collectively, our findings confirm a critical albeit differential role of T-cell lymphopenia in the susceptibility to organ-specific autoimmune responses.-Fischer, H. J., Witte, A.-K., Walter, L., Gröne, H.-J., van den Brandt, J., Reichardt, H. M. Distinct roles of T-cell lymphopenia and the microbial flora for gastrointestinal and CNS autoimmunity. PMID:26740263

  5. Susceptibility and possible resistance mechanisms in the palm species Phoenix dactylifera, Chamaerops humilis and Washingtonia filifera against Rhynchophorus ferrugineus (Olivier, 1790) (Coleoptera: Curculionidae).

    Science.gov (United States)

    Cangelosi, B; Clematis, F; Curir, P; Monroy, F

    2016-06-01

    Rhynchophorus ferrugineus, known as the Red Palm Weevil (RPW), is reported as a pest of up to 40 palm species. However, the susceptibility degree and the defense mechanisms of these species against this weevil are still poorly known. In Europe, the RPW is a major pest of Phoenix canariensis while other palm species, including the congeneric Phoenix dactylifera, seem to be less suitable hosts for this insect. The aim of our study was to compare the defensive response of P. dactylifera, Chamaerops humilis and Washingtonia filifera against R. ferrugineus and try to define the mechanisms of resistance that characterize these species. Bioassays were carried out to evaluate the mortality induced on RPW larvae by extracts from the leaf rachis of the studied palm species. Tests at semi-field scale were also conducted, based either on forced palm infestation, with larvae of RPW, or on natural infestation, with adult females. Rachis extracts from C. humilis and W. filifera caused 100% larval mortality after 2 days of exposure, while extracts of P. dactylifera did not impair larval survival. Independently of the effect of the leaf extracts, the weevils were unable to naturally infest the three palm species, although larval survival was high after forced infestation of the plants. We concluded that the observed lack of infestation of P. dactylifera by RPW is due to factors other than antibiosis. In W. filifera and C. humilis, although the presence of antixenosis mechanisms cannot be excluded, resistance to R. ferrugineus seems to rely on the presence of antibiosis compounds. PMID:26976073

  6. Identification of distinct quantitative trait loci associated with defence against the closely related aphids Acyrthosiphon pisum and A. kondoi in Medicago truncatula

    KAUST Repository

    Guo, Su-Min

    2012-03-21

    Aphids are a major family of plant insect pests. Medicago truncatula and Acyrthosiphon pisum (pea aphid, PA) are model species with a suite of resources available to help dissect the mechanism underlying plant-aphid interactions. A previous study focused on monogenic and relatively strong resistance in M. truncatula to PA and other aphid species. In this study a moderate resistance to PA was characterized in detail in the M. truncatula line A17 and compared with the highly susceptible line A20 and the more resistant line Jester. The results show that PA resistance in A17 involves both antibiosis and tolerance, and that resistance is phloem based. Quantitative trait locus (QTL) analysis using a recombinant inbred line (RIL) population (n=114) from a cross between A17 and A20 revealed that one locus, which co-segregated with AIN (Acyrthosiphon-induced necrosis) on chromosome 3, is responsible for the reduction of aphid biomass (indicator of antibiosis) for both PA and bluegreen aphid (BGA, A. kondoi), albeit to a lesser degree for PA than BGA. Interestingly, two independent loci on chromosomes 5 and 3 were identified for the plant biomass reduction (indicator of plant tolerance) by PA and BGA, respectively, demonstrating that the plant\\'s tolerance response to these two closely related aphid species is distinct. Together with previously identified major resistant (R) genes, the QTLs identified in this study are powerful tools to understand fully the spectrum of plant defence against sap-sucking insects and provide opportunities for breeders to generate effective and sustainable strategies for aphid control. 2012 The Author.

  7. SOIL FUNGISTASIS AGAINST FUSARIUM GRAMINEARUM UNDER DIFFERENT CROP MANAGEMENT SYSTEMS

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    Bruno Brito Lisboa

    2015-02-01

    Full Text Available Soil management, in terms of tillage and cropping systems, strongly influences the biological properties of soil involved in the suppression of plant diseases. Fungistasis mediated by soil microbiota is an important component of disease-suppressive soils. We evaluated the influence of different management systems on fungistasis against Fusarium graminearum, the relationship of fungistasis to the bacterial profile of the soil, and the possible mechanisms involved in this process. Samples were taken from a long-term experiment set up in a Paleudult soil under conventional tillage or no-tillage management and three cropping systems: black oat (Avena strigose L. + vetch (Vicia sativa L./maize (Zea mays L. + cowpea (Vigna sinensis L., black oat/maize, and vetch/maize. Soil fungistasis was evaluated in terms of reduction of radial growth of F. graminearum, and bacterial diversity was assessed using ribosomal intergenic spacer analysis (RISA. A total of 120 bacterial isolates were obtained and evaluated for antibiosis, and production of volatile compounds and siderophores. No-tillage soil samples showed the highest level of F. graminearum fungistasis by sharply reducing the development of this pathogen. Of the cropping systems tested, the vetch + black oat/maize + cowpea system showed the highest fungistasis and the oat/maize system showed the lowest. The management system also affected the genetic profile of the bacteria isolated, with the systems from fungistatic soils showing greater similarity. Although there was no clear relationship between soil management and the characteristics of the bacterial isolates, we may conclude that antibiosis and the production of siderophores were the main mechanisms accounting for fungistasis.

  8. Characterizing CMN1308, a Novel Strain of Bacillus amyloliquefaciens, for Potential Biological Control Application

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    Xuehua ZHANG

    2016-06-01

    Full Text Available Fungal diseases of plants continue to contribute to heavy crop losses in spite of the best control efforts of plant pathologists. Breeding for disease-resistant varieties and the application of synthetic chemical fungicides are the most widely accepted approaches in plant disease management. CMN1308 strain of Bacillus amyloliquefaciens was isolated from healthy Chinese chestnut fruit, which has antibiosis and induced resistance to the prevention mechanism of pathogenic bacterium after picking. In order to evaluate the antibiosis mechanism, CMN1308 was fostered with the method of confront culture. The antimicrobial components were also isolated from the culture of CMN1308, and their stability and antimicrobial activity was tested under different treatments such as temperature, pH and UV. The results showed that CMN1308 displays advantages in regard to spatial competition against the major pathogens of chestnut, Rhizopus stolonifer, Fusarium solani, Stachybotrys chartarum, Cryphonectria parasitica, Lasiodiplodia theobromae, Penicillium expansum and Aspergillus niger. Among this, CMN1308 had the best antimicrobial activity against P. expansum, with the inhibition zone diameter of 27.1 mm. The antimicrobial material isolated from CMN1308 culture showed a strong inhibition to the growth of P. expansum hyphal and also had a good stability to high temperature, alkali media and UV, but was sensitive to acidic conditions. Furthermore, CMN1308 increased the peroxidase, polyphenol oxidase activity and reduced the MDA content in chestnuts after infecting by pathogenic fungi. Thus, producing antibiotic compounds and inducible resistance are the main factors that may explain the antibacterial mechanism of CMN1308 on chestnut pathogenic. The results of this study might help to optimize the practical use of CMN1308 in the biological control of chestnut rot or other fruit rot infected by pathogenic fungi.

  9. Resistance of straight and runner growing habit peanut cultivars to Spodoptera cosmioides in laboratory = Resistência de cultivares de amendoim de hábitos de crescimento ereto e rasteiro a Spodoptera cosmioides em laboratório

    Directory of Open Access Journals (Sweden)

    Nara Elisa Lobato Rodrigues

    2013-04-01

    Full Text Available Abstract - This work aimed to evaluate the resistance in straight and runner growing habit peanut cultivars to Spodoptera cosmioides (Walker (Lepidoptera: Noctuidae. In non-preference for feeding tests the leaflets were placed into Petri dishes, where one third-instar larva per cultivar was released in free-choice and non-choice tests. Larvae attractiveness to the cultivars was evaluated through counting the number of insects on the leaflets in pre-determined times, and, at the end of the experiment, the leaf area consumed was quantified and a visual consumption score per cultivar was assigned. In antibiosis est, neonate larvae were individualized into Petri dishes, where daily, new leaflets were provided. We evaluated the biological aspects: larvae, pre-pupa, pupae and total period and viability (larvae eclosion to adult emergence, weight of larvae and pupae, sex ratio and adult longevity. We concluded that the straight growing habit peanut IAC Tatu ST was less consumed by the larvae, in non-choice test. The runner growing cultivars did not show non-preference for feeding resistance-types. Among the straight growing cultivars, IAC 8112 extended the biological cycle of S. cosmioides, characterizing antibiosis resistance-type, whereas IAC Tatu ST, IAC 22 and IAC 5 were susceptible. For the runner growing cultivars, IAC Runner 886 and IAC 147 stood out as antibiosis resistance-type to S. cosmioides, and IAC Caiapó and IAC 125 were susceptible. = Resumo - O trabalho teve como objetivo verificar a resistência em cultivares de amendoim de hábito de crescimento ereto e rasteiro a Spodoptera cosmioides (Walker (Lepidoptera: Noctuidae. Nos testes de não preferência para alimentação, folíolos das cultivares foram dispostos em placas de Petri, liberando-se uma lagarta de 3º instar por cultivar em testes com e sem chance de escolha. A atratividade das lagartas às cultivares foi avaliada em tempos pré-estabelecidos contando-se o número de

  10. ASPECTOS BIOLÓGICOS DE Anticarsia gemmatalis HÜEBNER (LEPIDOPTERA: NOCTUIDAE EM CULTIVARES DE SOJA (Glycine max MERRIL BIOLOGICAL ASPECTS OF Anticarsia gemmatalis HÜEBNER (LEPIDOPTERA: NOCTUIDAE ON SOYBEAN CULTIVARS

    Directory of Open Access Journals (Sweden)

    José Baldin Pinheiro

    2007-09-01

    Full Text Available

    O trabalho foi desenvolvido no Laboratório de Entomologia da Escola de Agronomia da Universidade Federal de Goiás, em condições controladas de temperatura (25+2ºC, umidade relativa (40+10% e fotofase de 13h, com o objetivo de estudar o efeito das cultivares Emgopa 316, FT-Estrela, IAC 100 e IAC 17, no desenvolvimento de Anticarsia gemmatalis. Foram observadas a duração do período larval, o tamanho e o peso de lagartas e peso de pupas. Na cultivar Emgopa 316, as larvas apresentaram uma diminuição no período larval e um aumento nos pesos larval e pupal, enquanto IAC 100 mostrou alguma evidência de antibiose, aumentando o período larval e diminuindo o peso de lagartas e de pupas.

    PALAVRAS-CHAVE: Resistência; antibiose; insecta.

    A laboratory work was conducted at Universidade Federal de Goiás, under controlled conditions of temperature (25+2º, relative humidity (40+10% and photophase (13h. The objective was to evaluate the effect of the soybean cultivars Emgopa 316, FT-Estrela, IAC 100 and IAC 17 on the development of Anticarsia gemmatalis Hüebner, 1818. Duration of the development phases, length of larvae and weight of pupae were observed. Emgopa 316 showed a decreasing duration of larval stage and an increase in larvae and pupae weight; IAC 100 showed some evidence of antibiosis, increasing the larval stage and decreasing larvae and pupae weight.

    KEY-WORDS: Insecta; resistance; antibiosis.

  11. Antimicrobial and antifouling activities achieved by extracts of seaweeds from Gulf of California, Mexico Actividades antimicrobiana y anti-incrustante obtenidas de los extractos de algas marinas del Golfo de California, México

    Directory of Open Access Journals (Sweden)

    Ruth Noemí Águila-Ramírez

    2012-04-01

    Full Text Available Six species of common seaweed extracts were tested in laboratory assays: Dictyota flabellata, Padina concrescens, Laurencia johnstonii, Gymnogongrus martinensis, Ulva lactuca and Codium fragile for potential industrial applications through evaluation of the antibacterial activity against pathogenic bacteria (5 strains and the antifouling potency against the growth of key species of marine colonisers (7 bacteria, 5 fungi and 11 microalgae. The organic extract of L. johnstonii, U. lactuca and D. flabellata have bacterial antibiosis. The ethereal extracts were more active in comparison with buthanol extracts against the bacterial strain Staphylococcus aureus. The best antifouling results were obtained with U. lactuca and L. johnstonii(0.1-1 μg ml-1 against all strains tested. C.fragile exhibited significant antifouling activity with minimum inhibitory concentration (MIC between 1-10 μg ml-1 against marine microalgae Rhodosorus magnei, Neorhodella cyanea and Prymnesium calathiferum.Se analizaron seis especies de macroalgas comunes del Golfo de California: Dictyota flabellata, Padina concrescens, Laurencia johnstonii, Gymnogongrus martinensis, Ulva lactuca y Codium fragile para determinar su potencial aplicación industrial, a través de la evaluación de la actividad antibacteriana frente a bacterias patógenas (5 cepas, y el potencial anti-incrustante como inhibidores de crecimiento de especies colonizadoras en ambientes marinos (7 bacterias, 5 hongos y 11 microalgas. Los extractos orgánicos de L. johnstonii, U. lactuca y D. flabellata presentaron antibiosis bacteriana. Los extractos etéreos fueron más activos en comparación con los extractos de butanol frente a la cepa bacteriana Staphylococcus aureus. Los mejores resultados de actividad anti-incrustante se obtuvieron con U. lactuca y L. johnstonii (0.1-1 μg ml-1 frente a todas las cepas probadas. C. fragile mostró una significativa actividad anti-incrustante, presentando una concentraci

  12. Tomato responds to green peach aphid infestation with the activation of trehalose metabolism and starch accumulation.

    Science.gov (United States)

    Singh, Vijay; Shah, Jyoti

    2012-06-01

    The disaccharide trehalose and trehalose-6-phosphate that are present in trace amounts are suggested to have a signaling function in plants. Recently, it was demonstrated that trehalose metabolism contributes to Arabidopsis thaliana defense against the green peach aphid (GPA; Myzus persicae Sülzer), an important insect pest of a large variety of plants. TPS11 (TREHALOSE PHOSPHATE SYNTHASE11)-dependent trehalose metabolism was shown to curtail GPA infestation by promoting starch accumulation and expression of the PAD4 (PHYTOALEXIN-DEFICIENT4) gene, which has important roles in regulating antibiosis and antixenosis against GPA. Here we show that trehalose metabolism is similarly activated in leaves of GPA-infested tomato (Solanum lycopersicum) plants and likely contributes to tomato defense against GPA. GPA-infested leaves of tomato accumulated trehalose, which was accompanied by the transient upregulation of SlTPS11, a homolog of the Arabidopsis TPS11. GPA-infestation was also accompanied by starch accumulation and the upregulation of SlPAD4, the tomato homolog of Arabidopsis PAD4. Furthermore, trehalose application induced SlPAD4 expression and starch accumulation, and curtailed GPA infestation, suggesting that like in Arabidopsis trehalose contributes to tomato defense against GPA.

  13. 2010年我国工程塑料应用进展%ADVANCE IN THE ENGINEERING PLASTICS APPLICATION OF CHINA IN 2010

    Institute of Scientific and Technical Information of China (English)

    闫烨; 杨超

    2011-01-01

    根据2010年国内公开发表的文献,综述了我国工程塑料及改性塑料在机车车辆、电子电器、环保抗菌、机械设备、建材、军事及航天装备、薄膜、医疗用品等领域的应用情况及研究进展,并介绍了以上领域内塑料新产品的开发、性能评价和使用效果.指出2010年我国工程塑料新产品的开发应用重点是机车车辆、电子电器、薄膜等领域.%According to the public articles at home in 2010, the application of the engineering plastics and modified plastics in the fields of vehicles, electrics and electronics, environmental protection and antibiosis, mechanical equipment, building materials,military and space flight equipment, films, medical supplies, etc. and the research advance were presented. The development, performance evaluation and use effect of the new products of plastics in the above-mentioned rields were also summarized. It was pointed out that the key research and application fields in 2010 were vehicles, electrics and electronics, film, etc.

  14. 儿茶素的药理作用研究综述%Review of research on pharmacological effects of catechins

    Institute of Scientific and Technical Information of China (English)

    徐先祥

    2012-01-01

    The research progress on the pharmacology of catechins and its analogues was reviewed from remarkable pharmacological activities such as antioxidation, cardioprotection, anticancer effect, antibiosis, antiviral, anti-inflammation, immunomodulation, neuroprotection, regulation of glucose and lipid metabolism and so on. It is indicated that catechins has the important medical care application value,future studies on catechins might focus on chiral resolutions and their interactions with metallic ions and proteins in vivo.%对儿茶素及其类似化合物所具有的抗氧化、保护心血管、抗肿瘤、抗菌、抗病毒、抗炎、免疫调节、神经保护、调节糖脂代谢等药理作用进行了综述,指出其具有重要的医疗保健应用价值,儿茶素类的手性研究及其体内与金属离子、蛋白质等物质的相互作用将是今后研究开发的重点.

  15. Evaluación de la resistencia a Schizaphis graminum (Hemiptera: Aphididae en cebada

    Directory of Open Access Journals (Sweden)

    Erica F. TOCHO

    2012-01-01

    Full Text Available El pulgón verde de los cereales, Schizaphis graminum (Rondani, es una de las principales plagas de estos cultivos en el mundo y también presente en Argentina. Si bien el control químico es la práctica más utilizada, el uso de variedades resistentes (uno de los componentes principales del MIP es la estrategia más efectiva y ambientalmente más amigable para el control de plagas. Dado que las plantas presentan distintos mecanismos que les permiten defenderse de los insectos, el objetivo de este trabajo fue caracterizar la resistencia a Schizaphis graminum en una población de líneas recombinantes de cebada, e identificar aquellas con mejores características, portadoras de genes de resistencia a este insecto. La antixenosis fue analizada por la prueba de libre selección de hospederos. La antibiosis se evaluó por los parámetros del ciclo y el desarrollo del áfido y la tolerancia por características de crecimiento de las plantas bajo infestación. Al menos ocho líneas antibióticas fueron más tolerantes que sus testigos, presentando similares pesos secos, área foliar y contenido de clorofila bajo infestación. Estas líneas portadoras de genes de resistencia pueden ser de utilidad en los planes de mejora de la cebada.

  16. Research advance of medicinal properties of the fruit and the protein MAP30 in Momordica charantia L.%苦瓜果实的药用和苦瓜蛋白MAP30的研究进展

    Institute of Scientific and Technical Information of China (English)

    赵妍; 丁国华; 鲍宁宇

    2009-01-01

    Bitter melon (Momordica charantia L.) is a plant suited for both food and medicine. Its fruit contains many kinds of active components which have actions of depression blood sugar, antivirus, antitumour, antifertility, antioxidation and antibiosis etc. Research conditions in recent years on medicinal properties of bitter melon fruits and MAP30 (Momordica anti-HIV protein of 30 ku) were reviewed in this paper. It illuminated health functions on bitter melon and research advances on medicinal domain. Research and applied prospect were looked ahead.%苦瓜是药食同源的蔬菜,其果实中含有多种有效成分,具有降血糖、抗病毒、抗肿瘤、抗生育、抗氧化、抑菌等功能特性.文章综述了近年来国内外苦瓜及苦瓜蛋白MAP30(Momordica anti-HIV Protein of 30 ku)的研究情况,阐述了苦瓜的保健功能及其在医学领域的应用研究进展,并展望了其研究应用前景.

  17. Ninety-Day Subchronic Oral Toxicity Study of Senecio scandens Extract in Rats.

    Science.gov (United States)

    Wang, Xiu-Kun; Zhao, Yong; Liu, Ting; Yi, Yan; Li, Chun-Ying; Wang, Hong-Jie; Wang, Chang-Hong; Wang, Zheng-Tao; Ye, Zu-Guang; Liang, Ai-Hua

    2015-01-01

    The present study assessed the safety/toxicity of Senecio scandens, a well-known Chinese herb that is used as an anti-inflammatory, antibiosis, and antipyretic drug. A 90-d subchronic oral toxicity study of S. scandens was performed in Wistar rats. The extract of S. scandens was administered orally to male and female rats at a single dose of 225, 450, and 900 mg/kg/d. There was no obvious toxicity. Certain changes in hematology and coagulation parameters (red cell distribution width (RDW), platelet count (PLT), monocyte percentage (Mo%), activated partial thromboplastin time (APTT), prothrombin time (PT)) were observed in some administration groups. In regards to the blood biochemical parameters, the levels of creatinine (CRN), potassium, and chloride were increased in a number of the treated rats. There were no significant changes in other hematology, coagulation, or biochemical parameters in rats orally administered S. scandens. S. scandens has a slight effect on rat coagulation and metabolism systems. The herb was safe at all doses tested, but caution should be taken when administering S. scandens at higher doses. PMID:26195160

  18. Improving biocontrol activity of Pseudomonas fluorescens through chromosomal integration of 2,4-diacetylphloro- glucinol biosynthesis genes

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hongyou; WEI Hailei; LIU Xili; WANG Ye; ZHANG Liqun; TANG Wenhua

    2005-01-01

    Antibiotic 2,4-diacetylphloroglucinol (2,4- DAPG) produced by Pseudomonas fluorescens CPF-10 and 2P24 is a principal factor enabling bacteria to suppress plant diseases caused by soilborne pathogens. In this study, a 2,4-DAPG biosynthesis locus phlACBDE cloned from strain CPF-10 was assembled into a mini-Tn5 transposon and introduced into the chromosome of P. fluorescens P32 (2,4- DAPG-), CPF-10 and 2P24 to construct the 2,4-DAPG overproducing derivatives P32-38, CPF10-9 and 2P24-48, respectively. All the transgenic strains showed an enhanced antibiosis capacity against plant microbial pathogens in vitro and two strains, P32-38 and CPF10-9, provided significantly better protection against wheat take-all disease caused by Gaeumannomyces graminis var. tritici and tomato bacterial wilt caused by Ralstonia solanacearum in greenhouse. Compared to their parental strains, the 2,4-DAPG overproducing derivatives colonized to the same extent on the wheat tips in the autoclaved soil, but developed larger populations in natural soil. These results indicated that production of antibiotics 2,4- DAPG by biological control pseudomonads can contribute not only to their disease suppression capacities but also to the ecological competence in the resident microflora. Our research also suggests that it is a realistic approach to improve biocontrol capacity of P. fluorescens through the genetic modification of its antibiotic 2,4-DAPG production.

  19. Poplar and its bacterial endophytes: coexistence and harmony

    Energy Technology Data Exchange (ETDEWEB)

    van der Lelie, D.; Taghavi, S.; Monchy, S.; Schwender, J.; Miller, L.; Ferrieri, R.; Rogers, A.; Zhu, W.; Weyens, N.; Vangronsveld, J.; Newman, L.

    2009-09-01

    Associations between plants and microorganisms are very complex and are the subject of an increasing number of studies. Here, we specifically address the relationship between poplar and its endophytic bacteria. The role and importance of endophytic bacteria in growth and development of their host plants is still underestimated. However, since many endophytes have a beneficial effect on their host, an improved understanding of the interaction between poplar and its endophytic bacteria has the potential to provide major breakthroughs that will improve the productivity of poplar. Endophytic bacteria can improve plant growth and development in a direct or indirect way. Direct plant growth promoting mechanisms may involve nitrogen fixation, production of plant growth regulators such as auxins, cytokinins and gibberellins, and suppression of stress ethylene synthesis by 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. Endophytic bacteria can indirectly benefit the plant by preventing the growth or activity of plant pathogens through competition for space and nutrients, antibiosis, production of hydrolytic enzymes, inhibition of pathogen-produced enzymes or toxins, and through systemic induction of plant defense mechanisms. Examples of applications for custom endophyte-host partnerships include improved productivity and establishment of poplar trees on marginal soils and the phytoremediation of contaminated soils and groundwater. A systems biology approach to understand the synergistic interactions between poplar and its beneficial endophytic bacteria represents an important field of research, which is facilitated by the recent sequencing of the genomes of poplar and several of its endophytic bacteria.

  20. Functional role of an endophytic Bacillus amyloliquefaciens in enhancing growth and disease protection of invasive English ivy (Hedera helix L.)

    Science.gov (United States)

    Soares, Marcos Antonio; Li, Jai-Yan; Bergen, Marshall; da Silva, Joaquim Manoel; Kowalski, Kurt P.; White, James Francis

    2015-01-01

    BackgroundWe hypothesize that invasive English ivy (Hedera helix) harbors endophytic microbes that promote plant growth and survival. To evaluate this hypothesis, we examined endophytic bacteria in English ivy and evaluated effects on the host plant.MethodsEndophytic bacteria were isolated from multiple populations of English ivy in New Brunswick, NJ. Bacteria were identified as a single species Bacillus amyloliquefaciens. One strain of B. amyloliquefaciens, strain C6c, was characterized for indoleacetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis against pathogens. PCR was used to amplify lipopeptide genes and their secretion into culture media was detected by MALDI-TOF mass spectrometry. Capability to promote growth of English ivy was evaluated in greenhouse experiments. The capacity of C6c to protect plants from disease was evaluated by exposing B+ (bacterium inoculated) and B− (non-inoculated) plants to the necrotrophic pathogen Alternaria tenuissima.ResultsB. amyloliquefaciens C6c systemically colonized leaves, petioles, and seeds of English ivy. C6c synthesized IAA and inhibited plant pathogens. MALDI-TOF mass spectrometry analysis revealed secretion of antifungal lipopeptides surfactin, iturin, bacillomycin, and fengycin. C6c promoted the growth of English ivy in low and high soil nitrogen conditions. This endophytic bacterium efficiently controlled disease caused by Alternaria tenuissima.ConclusionsThis study suggests that B. amyloliquefaciens plays an important role in enhancing growth and disease protection of English ivy.

  1. Assessment of the Role of Local Strawberry Rhizosphere—Associated Streptomycetes on the Bacterially—Induced Growth and Botrytis cinerea Infection Resistance of the Fruit

    Directory of Open Access Journals (Sweden)

    D. İpek Kurtböke

    2010-12-01

    Full Text Available The future need for sustainable agriculture will be met in part by wider use of biological control of plant pathogens over conventional fungicides hazardous to the environment and to public health. Control strategies involving both (i direct use of microorganisms antagonistic to the phytopathogen, and (ii use of bioactive compounds (secondary metabolites/antibiotic compounds from microorganisms on the phytopathogen were both adapted in order to investigate the ability of streptomycetes isolated from the rhizosphere of strawberry plants to promote the growth of the fruit and suppress Botrytis cinerea causing strawberry rot on the Sunshine Coast, Queensland, Australia. In vitro studies showed that 25/39 streptomycetes isolated from strawberry field soils inhibited B. cinerea growth by antifungal activity, ranging from antibiosis to volatile compound production. However, when non-volatile antifungal compounds were extracted and applied aerially to the actively growing strawberry fruits infected with B. cinerea, a significant disease reduction was not recorded. On the other hand, plant and fruit growth was promoted by the presence of actively growing streptomycetes in container media. Findings might indicate that live streptomycete inoculum can be used as growth promoting agent in container media for this economically important crop.

  2. Marine isolates of Trichoderma spp. as potential halotolerant agents of biological control for arid-zone agriculture.

    Science.gov (United States)

    Gal-Hemed, Inbal; Atanasova, Lea; Komon-Zelazowska, Monika; Druzhinina, Irina S; Viterbo, Ada; Yarden, Oded

    2011-08-01

    The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29 Trichoderma strains previously isolated from Mediterranean Psammocinia sp. sponges, the greatest number of isolates belong to the Trichoderma longibrachiatum-Hypocrea orientalis species pair (9), H. atroviridis/T. atroviride (9), and T. harzianum species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of T. asperelloides and two putative new species, Trichoderma sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified. In vitro salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions. In vitro antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived Trichoderma isolates, identified as T. atroviride and T. asperelloides, respectively, effectively reduced Rhizoctonia solani damping-off disease on beans and also induced defense responses in cucumber seedlings against Pseudomonas syringae pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents.

  3. Chemical compsition and pharmacological action of jojoba:research advances%好好芭化学组成及药理作用研究进展

    Institute of Scientific and Technical Information of China (English)

    杨雪鸥; 吴然; 张林; 耿红卫

    2014-01-01

    Jojoba(the plant belonging to Simmondsiaceae)seeds are not only a kind of global special oil resources but also a type of good folk medicines because they are riched in jojoba oil and simmondsin and have many pharmacological effects such as anti-inflammatory effect,food inhibitor and promoting-antibiosis. The paper reviews the studies on jojoba chemical compositim, extraction and purification,detection and analysis methods,pharmacological activity and dosage development,in order to provide reference for further research and application.%加州西蒙得木(好好芭)属西蒙得木科植物,其种子不仅是世界特种油料的宝库,也是良好的药用资源,富含好好芭油和西蒙得木素,具有抗炎、减肥以及促抗菌等功效。本文综述了好好芭的药学研究进展,包括化学成分及提取方法、检测方法、药理作用及制剂研究等方面的内容,为好好芭的进一步研究开发提供参考。

  4. 迷迭香酸的提取纯化及生物活性研究进展%Research Progress on Extraction, Purification and Biological Activities of Rosmarinic Acid

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    迷迭香酸作为强抗氧化剂,具有抗菌、抗炎、抗病毒、抗肿瘤等多种生物活性。介绍了迷迭香酸的提取及纯化方法,重点讨论了其在抗菌抗病毒、抗氧化及清除自由基、抗炎及免疫调节、保护神经系统、抗辐射抗肿瘤、抑制黄嘌呤氧化酶和保护肝脏与肺等多方面的生物活性,旨在为其规模化制备和应用提供依据。%Rosmarinic acid as a very strong antioxidants exists in rosemary with a high content. It has various biological activities such as anti-biotic, anti-inflammatory, anti-virus and anti-cancer activities. In order to offer more information for large-scale preparation and application, a brief review is presented on the extraction, purification methods. The biological activities of rosmarinic acid, such as antibiosis, antivirus, anti-oxidation , radical-scavenging, anti-inflammatory, immunoregulation, protecting nervous system, anti-radiation, antitumor, inhibition of xanthine oxidase and protection of livers and lungs are particularly discussed.

  5. Microbial antagonism as a potential solution for controlling selected root pathogens of crops

    Science.gov (United States)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2016-04-01

    Root pathogens of crops can cause large reduction in yield, however, there is a limited range of effective methods to control such pathogens. Soilborne pathogens that infect roots often need to survive in the rhizosphere, where there is high competition from other organisms. In such hot spots of microbial activity and growth, supported by root exudates, microbes have evolved antagonistic mechanisms that give them competitive advantages in winning the limited resources. Among these mechanisms is antibiosis, with production of some significant antifungal compounds including, antibiotics, volatile organic compounds, hydrogen cyanide and lytic enzymes. Some of these mechanisms may suppress disease through controlling the growth of root pathogens. In this project we isolated various fungi and bacteria that suppress the growth of cotton pathogens in vitro. The pathogen-suppressive microbes were isolated from cotton production soils that are under different management strategies, with and without the use of organic amendments. The potential of pathogen-suppressing microbes for controlling the black root rot disease, caused by the soilborne pathogen Thielaviopsis basicola, was confirmed using soil assays. We identified isolates with potential use as inoculant for cotton production in Australia. Having isolated a diverse group of antagonistic microbes enhances the probability that some would survive well in the soil and provide an alternative approach to address the problem of root disease affecting agricultural crops.

  6. Production and antimicrobial activity of 3-hydroxypropionaldehyde from Bacillus subtilis strain CU12.

    Science.gov (United States)

    Wise, C; Novitsky, L; Tsopmo, A; Avis, T J

    2012-12-01

    Bacillus subtilis strains are known to produce a vast array of antimicrobial compounds. However, some compounds remain to be identified. Disk assays performed in vitro with Bacillus subtilis CU12 showed a significant reduction in mycelial growth of Alternaria solani, Botrytis cinerea, Fusarium sambucinum, and Pythium sulcatum. Crude B. subtilis culture filtrates were subsequently extracted with ethyl acetate and butanol. A bioassay guided purification procedure revealed the presence of one major antifungal compound in the butanol extract. Purification of the compound was performed using a reverse-phase C18 solid phase extraction (SPE) cartridge and flash column chromatography. NMR data showed that the main antimicrobial compound was a cyclic dimer of 3-hydroxypropionaldehyde (HPA). This study demonstrated the antimicrobial activity of B. subtilis strain CU12 against phytopathogenic microorganisms is mediated at least in part by the production of HPA. It also suggests that this B. subtilis strain could be effective at controlling pathogens through protection of its ecological niche by antibiosis. PMID:23179100

  7. Selection of endophytic fungi from comfrey (Symphytum officinale L.) for in vitro biological control of the phytopathogen Sclerotinia sclerotiorum (Lib.).

    Science.gov (United States)

    Rocha, Rafaeli; da Luz, Daniela Eleutério; Engels, Cibelle; Pileggi, Sônia Alvim Veiga; de Souza Jaccoud Filho, David; Matiello, Rodrigo Rodrigues; Pileggi, Marcos

    2009-01-01

    Biological control consists of using one organism to attack another that may cause economic damage to crops. Integrated Pest Management (IPM) is a very common strategy. The white mold produced by Sclerotinia sclerotiorum (Lib.) causes considerable damage to bean crops. This fungus is a soil inhabitant, the symptoms of which are characterized by water-soaked lesions covered by a white cottony fungal growth on the soil surface and/or the host plant. Possible biological control agents taken from plants are being investigated as phytopathogen inhibitors. These are endophytic microorganisms that inhabit the intercellular spaces of vegetal tissues and are often responsible for antimicrobial production. The objective of the present study was to select endophytic fungi isolated from comfrey (Symphytum officinale L.) leaves with in vitro antagonist potential against the phytopathogenic fungus S. sclerotiorum. Twelve isolates of endophytic fungi and a pathogenic strain of S. sclerotiorum were used in the challenge method. With the aid of this method, four endophytes with the best antagonistic activity against S. sclerotiorum were selected. Pathogen growth inhibition zones were considered indicative of antibiosis. The percentages of pathogenic mycelia growth were measured both with and without the antagonist, resulting in growth reductions of 46.7% to 50.0% for S. sclerotiorum. These analyses were performed by evaluating the endophytic/pathogenic mycelia growth in mm/day over an eight-day period of antagonistic tests. PMID:24031320

  8. Enhanced resistance to Spodoptera litura in endophyte infected cauliflower plants.

    Science.gov (United States)

    Thakur, Abhinay; Kaur, Sanehdeep; Kaur, Amarjeet; Singh, Varinder

    2013-04-01

    Endophytic fungi, which live within host plant tissues without causing any visible symptom of disease, are important mediators of plant-herbivore interactions. These endophytes enhance resistance of host plant against insect herbivores mainly by productions of various alkaloid based defensive compounds in the plant tissue or through alterations of plant nutritional quality. Two endophytic fungi, i.e., Nigrospora sp. and Cladosporium sp., were isolated from Tinospora cordifolia (Thunb.) Miers, a traditional indian medicinal plant. Cauliflower (Brassica oleracea L.) plants were inoculated with these two endophytic fungi. The effect of endophyte infected and uninfected cauliflower plants were measured on the survival and development of Spodoptera litura (Fab.), a polyphagous pest. Endophyte infected cauliflower plants showed resistance to S. litura in the form of significant increase in larval and pupal mortality in both the fungi. Inhibitory effects of endophytic fungi also were observed on adult emergence, longevity, reproductive potential, as well as hatchability of eggs. Thus, it is concluded that antibiosis to S. litura could be imparted by artificial inoculation of endophytes and this could be used to develop alternative ecologically safe control strategies. PMID:23575013

  9. Identification of QTL in soybean underlying resistance to herbivory by Japanese beetles (Popillia japonica, Newman).

    Science.gov (United States)

    Yesudas, C R; Sharma, H; Lightfoot, D A

    2010-07-01

    Soybean [Glycine max (L.) Merr.] was one of the most important legume crops in the world in 2010. Japanese beetles (JB; Popillia japonica, Newman) in the US were an introduced and potentially damaging insect pest for soybean. JBs are likely to spread across the US if global warming occurs. Resistance to JB in soybean was previously reported only in plant introductions. The aims here were to identify loci underlying resistance to JB herbivory in recombinant inbred lines (RILs) derived from the cross of Essex x Forrest cultivars (EF94) and to correlate those with loci with factors that confer insect resistance in soybean cultivars. The RIL population was used to map 413 markers, 238 satellite markers and 177 other DNA markers. Field data were from two environments over 2 years. Pest severity (PS) measured defoliation on a 0-9 scale. Pest incidence (PI) was the percentage of plants within each RIL with beetles on them. Antibiosis and antixenosis data were from feeding assays with detached leaves in petri plates. Five QTL were detected for the mean PS field trait (16% root knot nematode (LG F) but not other major loci underlying resistance to nematode or insect pests (LGs G, H and M).

  10. Isolation and analysis of mannose/trehalose/maltose specific lectin from jack bean with antibruchid activity.

    Science.gov (United States)

    Shanmugavel, Sakthivelkumar; Velayutham, Veeramani; Kamalanathan, Tamilarasan; Periasamy, Mullainadhan; Munusamy, Arumugam; Sundaram, Janarthanan

    2016-10-01

    A lectin with insecticidal property against the stored product pest, Callosobruchus maculatus was successfully isolated from the seeds of Canavalia virosa using standard affinity chromatography. The isolated molecule typically behaved like a lectin in its characteristics. It agglutinated indicator red blood cells (RBC) in its native as well as enzyme treated conditions. The enzyme treated RBC types exhibited a very high hemagglutination (HA) titre values and this property of isolated molecule behaved like arcelin, the lectin-like molecules reported from several species of Phaseolus. As a characteristic feature of a lectin, the isolated molecule effectively inhibited the agglutination of indicator RBC types with simple and complex carbohydrates including glycoproteins. This nature of the isolated molecule also relate with characteristic feature of arcelin isoforms in inhibiting HA activity with complex glycoproteins as reported in many studies. Most interestingly, the present study disclosed trehalose as a potent inhibitor of C. virosa lectin. Therefore, feeding insect pests on the lectin like arcelin could serve as antibiosis factor/anti-insect activity. The molecular characteristics of this isolated molecule and its mass studies too revealed its homology with arcelin, arcelin-1, 2 and 6 isoforms of P. vulgaris and lectin from Canavalia cathartica, C. lineata and C. brasiliensis. PMID:27238584

  11. Biological Activity of Coconut Oil:Medicinal Functions%椰子油的生理活性(I):药用功能

    Institute of Scientific and Technical Information of China (English)

    邓福明; 王挥; 赵松林; 陈卫军

    2013-01-01

    Coconut oil (CO) is a new kind of functional vegetable oil and very popular in the foreign market, which has a lot of biological function including antimicrobial, antioxidant, falling hematic fat and cholesterol, which has large market potential. At present, coconut oil market is almost a blank in China, some companies are grabbing market. This paper introduced detailedly the medicinal properties of CO in antibiosis, anti-virus, anti-inflammation and analgesia, protect the prostate gland, and the safety of the using, in order to provide theoretical basis for the development and application of the coconut oil.%椰子油是近年来国外市场非常流行的一种新型功能性植物油脂,具有抗菌、抗氧化、降血脂和胆固醇等多种生理功能,市场潜力巨大。目前,国内椰子油市场几乎空白,部分企业正纷纷抢占市场。本文详细介绍椰子油的抗菌、抗病毒、消炎镇痛、保护前列腺等药用功能及使用安全性,为椰子油的开发和应用提供一定的理论依据。

  12. [Secondary metabolites, lethality and antimicrobial activity of extracts from three corals and three marine mollusks from Sucre, Venezuela].

    Science.gov (United States)

    Ordaz, Gabriel; D'Armas, Haydelba; Yáñez, Dayanis; Hernández, Juan; Camacho, Angel

    2010-06-01

    The study of biochemical activity of extracts obtained from marine organisms is gaining interest as some have proved to have efficient health or industrial applications. To evaluate lethality and antimicrobial activities, some chemical tests were performed on crude extracts of the octocorals Eunicea sp., Muricea sp. and Pseudopterogorgia acerosa and the mollusks Pteria colymbus, Phyllonotus pomum and Chicoreus brevifrons, collected in Venezuelan waters. The presence of secondary metabolites like alkaloids, unsaturated sterols and pentacyclic triterpenes in all invertebrates, was evidenced. Additionally, sesquiterpenlactones, saponins, tannins, cyanogenic and cardiotonic glycosides were also detected in some octocoral extracts, suggesting that biosynthesis of these metabolites is typical in this group. From the lethality bioassays, all extracts resulted lethal to Artemia salina (LC50<1000 microg/ml) with an increased of lethal activity with exposition time. P. pomum extract showed the highest lethality rate (LC50=46.8 microg/ml). Compared to the octocorals, mollusks extracts displayed more activity and a greater action spectrum against different bacterial strains, whereas octocorals also inhibited some fungi strains growth. Staphylococcus aureus was the most susceptible to the antimicrobial power of the extracts (66.7%), whereas Pseudomonas aeruginosa, Candida albicans and Aspergillus niger were not affected. The antibiosis shown by marine organisms extracts indicates that some of their biosynthesized metabolites are physiologically active, and may have possible cytotoxic potential or as a source of antibiotic components. PMID:20527468

  13. Selección de rizobacterias por su antagonismo frente a microorganismos patógenos de cucurbitáceas /Screening of rhizobacteria for their antagonism against microbial pathogens of cucurbits.

    Directory of Open Access Journals (Sweden)

    Gilda Jiménez Montejo

    2014-04-01

    Full Text Available Resumen:El desarrollo de inoculantes microbianos a partir de aislamientos de rizobacterias con potencial para el control biológico de enfermedades de los cultivos agrícolas requiere de una rigurosa selección. Se obtuvieron aislamientos bacterianos de la rizosfera de papa (Solanum tuberosum L. y de maíz (Zea mays L. y de semillas de frijol (Phaseolus vulgaris L.. Las colonias que mostraron in vitro halos de inhibición de los patógenos de cucurbitáceas: Xanthomonas cucurbitae, Acidovorax avenae subsp. citrull y Fusarium oxysporum, se seleccionaron como antagonistas. A partir de las características morfológicas, fisiológicas y bioquímicas las cepas antagonistas F16/95 y Xph se identificaron con la especie Bacillus subtilis y la cepa 14A como Pseudomonas putida. Las pruebas presuntivas de producción de antibiocinas in vitro sugirieron modos de acción de las rizobacterias relacionados con antibiosis y competencia por el hierro mediante la producción de sideróforos. Los resultados indicaron el potencial de las cepas de rizobacterias antagonistas Bacillus subtilis (F16/95, Xph y Pesudomonas putida 14A para el control biológico de enfermedades de las cucurbitáceas./Abstract:

  14. Fabrication of Magnetic-Antimicrobial-Fluorescent Multifunctional Hybrid Microspheres and Their Properties

    Directory of Open Access Journals (Sweden)

    Ling-Han Xiao

    2013-04-01

    Full Text Available Novel magnetic-antimicrobial-fluorescent multifunctional hybrid microspheres with well-defined nanostructure were synthesized by the aid of a poly(glycidyl methacrylate (PGMA template. The hybrid microspheres were fully characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, Fourier transform infrared (FTIR, X-ray diffraction (XRD and digital fluorescence microscope. The as-synthesized microspheres PGMA, amino-modified PGMA (NH2-PGMA and magnetic PGMA (M-PGMA have a spherical shape with a smooth surface and fine monodispersity. M-PGMA microspheres are super-paramagnetic, and their saturated magnetic field is 4.608 emu·g−1, which made M-PGMA efficiently separable from aqueous solution by an external magnetic field. After poly(haxemethylene guanidine hydrochloride (PHGH functionalization, the resultant microspheres exhibit excellent antibacterial performance against both Gram-positive and Gram-negative bacteria. The fluorescence feature originating from the quantum dot CdTe endowed the hybrid microspheres with biological functions, such as targeted localization and biological monitoring functions. Combination of magnetism, antibiosis and fluorescence into one single hybrid microsphere opens up the possibility of the extensive study of multifunctional materials and widens the potential applications.

  15. Developmental profile of sinalbin (p-hydroxybenzyl glucosinolate) in mustard seedlings,Sinapis alba L., and its relationship to insect resistance.

    Science.gov (United States)

    Bodnaryk, R P

    1991-08-01

    Sinalbin was identified as a chemical component of insect anti-xenosis and antibiosis resistance mechanisms in seedlings ofSinapis alba by DEAE-Sephadex chromatography, HPLC, treatment with sulfatase and myrosinase, various feeding tests using artificial and natural substrates, and by measuring sinalbin concentrations in cotyledons and leaves during seedling development. The effects of sinaibin on feeding were dependent upon the insect species and upon the rapidly changing profile of sinaibin concentrations in the developing seedling. The high concentrations of sinalbin found in young cotyledons (up to 20 mM) and leaves (up to 10 mM) deterred the feeding of the flea beetle,Phyllotreta cruciferae Goeze and larvae of the bertha armyworm,Mamestra configurata Walker. The protection that sinalbin confers upon the vulnerable, newly emerged seedling (and upon tiny, young leaves) appears critical for the first few days of survival ofS. alba under feeding pressure from flea beetles in the field. The lower concentrations of sinaibin found in older cotyledons and leaves (2-3 mM) offer little or no protection againstP. cruciferae and may actually stimulate the feeding of this crucifer specialist. These concentrations of sinaibin, however, are still effective in reducing the level of feeding by larvae of the more generalist feederM. configurata. PMID:24257879

  16. Discrimination of Arabidopsis PAD4 activities in defense against green peach aphid and pathogens.

    Science.gov (United States)

    Louis, Joe; Gobbato, Enrico; Mondal, Hossain A; Feys, Bart J; Parker, Jane E; Shah, Jyoti

    2012-04-01

    The Arabidopsis (Arabidopsis thaliana) lipase-like protein PHYTOALEXIN DEFICIENT4 (PAD4) is essential for defense against green peach aphid (GPA; Myzus persicae) and the pathogens Pseudomonas syringae and Hyaloperonospora arabidopsidis. In basal resistance to virulent strains of P. syringae and H. arabidopsidis, PAD4 functions together with its interacting partner ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) to promote salicylic acid (SA)-dependent and SA-independent defenses. By contrast, dissociated forms of PAD4 and EDS1 signal effector-triggered immunity to avirulent strains of these pathogens. PAD4-controlled defense against GPA requires neither EDS1 nor SA. Here, we show that resistance to GPA is unaltered in an eds1 salicylic acid induction deficient2 (sid2) double mutant, indicating that redundancy between EDS1 and SID2-dependent SA, previously reported for effector-triggered immunity conditioned by certain nucleotide-binding-leucine-rich repeat receptors, does not explain the dispensability of EDS1 and SID2 in defense against GPA. Mutation of a conserved serine (S118) in the predicted lipase catalytic triad of PAD4 abolished PAD4-conditioned antibiosis and deterrence against GPA feeding, but S118 was dispensable for deterring GPA settling and promoting senescence in GPA-infested plants as well as for pathogen resistance. These results highlight distinct molecular activities of PAD4 determining particular aspects of defense against aphids and pathogens.

  17. Biological aspects of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on six bean genotypes; Aspectos biologicos de Bemisia tabaci (Genn.) biotipo B (Hemiptera: Aleyrodidae) em seis genotipos de feijoeiro

    Energy Technology Data Exchange (ETDEWEB)

    Oriani, Maria A. de G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Ecologia e Biologia Evolutiva; Vendramin, Jose D. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Entomologia, Fitopatologia e Zoologia Agricola; Brunherotto, Rogerio [Fundacao Municipal de Ensino Superior de Braganca Paulista, SP (Brazil)

    2008-03-15

    The silverleaf whitefly is one of the most harmful pests that attack bean crops, mainly for extracting large quantities of phloem sap and transmitting the bean golden mosaic virus. Resistant germplasm plants can be an important method for controlling this pest. The biological aspects of Bemisia tabaci B biotype on bean (Phaseolus vulgaris) genotypes were evaluated. The tests were conducted under laboratory conditions, with the following genotypes: Arc 1, Arc 3s, Arc 5s, G13028, G11056 and Porrillo 70. The bean plants in a stage IV-1 were infested during one day with silverleaf white flies. Afterwards the eggs and nymphs were observed until adult emergence. Longevity and fecundity of emerged insects were also evaluated. The longest development time occurred for nymphs fed on Arc 3s genotype (26.5 days), following by G11056 (25.9 days) and G13028 (25.3 days). The development period was 5.5 days longer in Arc 3s when compared with Porrillo 70. Also, the wild genotypes Arc 3s and G11056 showed higher mortality rates (94.7% and 83.1%, respectively), which may suggest antibiosis and/or feeding non preference resistance type. For this reason, although longevity and fecundity were not influenced when the whitefly fed on resistant genotypes (Arc 3s, G11056, G13028 and Arc 5s), those genotypes can be used for bean breeding program towards B. tabaci B biotype. (author)

  18. 丁樱教授妙用乌梅、乌梅炭经验拾萃%Experience of Professor DING Ying of using Fructus Mume and charred Fructus Mume

    Institute of Scientific and Technical Information of China (English)

    于淑文; 丁樱

    2013-01-01

      现代药理研究中药乌梅具有抗菌,驱虫,抗肿瘤,抗过敏,抗氧化,抗疲劳等[1]作用,长于生津止渴,敛肺止咳,安蛔。乌梅经炮制成乌梅炭后,则具有收敛止血、涩肠止泻等作用,临床上广泛用于久泻、久痢、便血、崩漏下血等。丁樱教授在30余年的临床研究中,辨证运用二药,疗效显著。%Fructus Mume has the effect of antibiosis, helminthicide, anti-tumor, anti-anaphylaxis, anti-oxygen, anti-fatigue etc, and it is good at promoting fluid production to quench thirst, astringing lung to stop cough and relieving ascaris colic. If Fructus Mume is processed into Charred Fructus Mume, it therefore has the effect of hemostasis with astringents and antidarrhea with astringent, widely used in lingering decanta, lingering dysentery, hematochezia and uterine bleeding. Professor Ding Ying has applied the two herbs on differentiation of symptoms and signs during the clinical study and research more than 30 years and great efficacy has been achieved.

  19. Pantoea agglomerans strain EH318 produces two antibiotics that inhibit Erwinia amylovora in vitro.

    Science.gov (United States)

    Wright, S A; Zumoff, C H; Schneider, L; Beer, S V

    2001-01-01

    Pantoea agglomerans (synonym: Erwinia herbicola) strain Eh318 produces through antibiosis a complex zone of inhibited growth in an overlay seeded with Erwinia amylovora, the causal agent of fire blight. This zone is caused by two antibiotics, named pantocin A and B. Using a genomic library of Eh318, two cosmids, pCPP702 and pCPP704, were identified that conferred on Escherichia coli the ability to inhibit growth of E. amylovora. The two cosmids conferred different antibiotic activities on E. coli DH5alpha and had distinct restriction enzyme profiles. A smaller, antibiotic-conferring DNA segment from each cosmid was cloned. Each subclone was characterized and mutagenized with transposons to generate clones that were deficient in conferring pantocin A and B production, respectively. Mutated subclones were introduced into Eh318 to create three antibiotic-defective marker exchange mutants: strain Eh421 (pantocin A deficient); strain Eh439 (pantocin B deficient), and Eh440 (deficient in both pantocins). Cross-hybridization results, restriction maps, and spectrum-of-activity data using the subclones and marker exchange mutants, supported the presence of two distinct antibiotics, pantocin A and pantocin B, whose biosynthetic genes were present in pCPP702 and pCPP704, respectively. The structure of pantocin A is unknown, whereas that of pantocin B has been determined as (R)-N-[((S)-2-amino-propanoylamino)-methyl]-2-methanesulfonyl-s uccina mic acid. The two pantocins mainly affect other enteric bacteria, based on limited testing. PMID:11133457

  20. 壳聚糖涂膜在动物性产品保藏方面的研究进展

    Institute of Scientific and Technical Information of China (English)

    韩剑花; 于有伟

    2013-01-01

    Chitosan is an alkaline polysaccharide originating of nature, which is safe and non-toxic. It has many excellent properties such as biocompatibility, biodegradability, forming film and antibiosis. After the animal products including meat, egg and aquatic product are coated with chitosan, their preserving effects are improved and the shelf life is prolonged accordingly. Chitosan coating applied in animal product preservation will be further investigated in depth and width in future.%壳聚糖是源于自然界的一种高分子碱性多糖,安全、无毒,具有良好的生物相容性、生物降解性、成膜性和抑菌性能。采用壳聚糖涂膜肉类、禽蛋和水产品之后,产品的保鲜效果得到改善,货架期延长。壳聚糖涂膜在动物性产品保藏方面将会得到更加深入和广泛的研究。

  1. 壳聚糖在果蔬保鲜中的应用研究进展%Progress in Chitosan and Its Application on Fruit and Vegetable Fresh Keeping

    Institute of Scientific and Technical Information of China (English)

    王颖; 曾霞; 王春

    2012-01-01

    Chitosan is a natural high molecular compound with the characteristic of non-toxicity, safety, easy membrane formation and antibiosi. The mechanism of chitosan on tresh keeping ttuits and vegetables are introduced. And the application of chitosan application of chitosan on the fruit and vegetable fresh-keeping are reviewed. In addit ion, some suggestions of the development are also presented, amied to provide theory evidence for the yielding application of chitosan in agriculture.%壳聚糖是一种天然高分子化合物,具有无毒、安全、易成膜、抗菌等特性。该文介绍了壳聚糖保鲜果蔬的机理,综述了壳聚糖在果蔬贮藏保鲜中的最新进展,分析了目前研究中存在的问题并对发展方向作出展望,旨在为实现壳聚糖在农业上的生产化应用提供理论依据。

  2. 氧肟酸在植物抗虫性中的作用%Roles of Hydroxamic Acids in Plant Resistance Against Insect

    Institute of Scientific and Technical Information of China (English)

    李庆; 杨群芳

    2000-01-01

    氧肟酸是一类广泛存在于禾本科植物的植物次生代谢物,与植物抗虫性关系密切,现已明确氧肟酸与欧洲玉米螟 Ostrinia nubilalis(Hubner)、亚洲玉米螟Ostrinia furnacalis(Guenee)、玉米蚜Rhopalosiphum maidis(Fitch)、麦二叉蚜 Shizaphis graminum(Rondani)、禾谷缢管蚜Rhopalosiphum paai(L.)、麦无网蚜Melopolophium dirho-dum(Walker)和麦长管蚜Silobion avenae F.的抗性有关。丁布(DIMBOA)作为氧肟酸的主要类型,主要通过抗生性或不选择性在植物抗虫性中起重要作用。%Hydroxamic acids (Hx) are secondary plant chemicals widely presenting in Gramineae, It is shown that Hx were associated with resistance of plant to Ostrinia nubilalis (Hubner), Ostrinia furnacalis (Guenee), Rhopalosiphum midis (Fitch), Schizaphis graminum (Rondani), Rhopalosiphum padi (L.), Metopolophium dirhodum (Walker) and Sitobion avenae F.. DIMBOA (one of Hx) mainly exhibits resistance through antibiosis and antixenosis in these pests mentioned above.

  3. Degradation of oxalic acid by the mycoparasite Coniothyrium minitans plays an important role in interacting with Sclerotinia sclerotiorum.

    Science.gov (United States)

    Zeng, Li-Mei; Zhang, Jing; Han, Yong-Chao; Yang, Long; Wu, Ming-de; Jiang, Dao-Hong; Chen, Weidong; Li, Guo-Qing

    2014-08-01

    Coniothyrium minitans (Cm) is a mycoparasite of the phytopathogenic fungus Sclerotinia sclerotiorum (Ss). Ss produces a virulence factor oxalic acid (OA) which is toxic to plants and also to Cm, and Cm detoxifies OA by degradation. In this study, two oxalate decarboxylase genes, Cmoxdc1 and Cmoxdc2, were cloned from Cm strain Chy-1. OA and low pH induced expression of Cmoxdc1, but not Cmoxdc2. Cmoxdc1 was partially responsible for OA degradation, whereas Cmoxdc2 had no effect on OA degradation. Disruption of Cmoxdc1 in Cm reduced its ability to infect Ss in dual cultures where OA accumulated. Compared with Chy-1, the Cmoxdc1-disrupted mutants had reduced expression levels of two mycoparasitism-related genes chitinase (Cmch1) and β-1,3-glucanase (Cmg1), and had no detectable activity of extracellular proteases in the presence of OA. On the other hand, the cultural filtrates of the Cmoxdc1-disrupted mutants in OA-amended media showed enhanced antifungal activity, possibly because of increased production of antifungal substances under acidic pH condition resulted from reduced Cmoxdc1-mediated OA degradation. This study provides direct genetic evidence of OA degradation regulating mycoparasitism and antibiosis of Cm against Ss, and sheds light on the sophisticated strategies of Cm in interacting with metabolically active mycelia and dormant sclerotia of Ss. PMID:24467446

  4. Selection of endophytic fungi from comfrey (Symphytum officinale L.) for in vitro biological control of the phytopathogen Sclerotinia sclerotiorum (Lib.)

    Science.gov (United States)

    Rocha, Rafaeli; da Luz, Daniela Eleutério; Engels, Cibelle; Pileggi, Sônia Alvim Veiga; de Souza Jaccoud Filho, David; Matiello, Rodrigo Rodrigues; Pileggi, Marcos

    2009-01-01

    Biological control consists of using one organism to attack another that may cause economic damage to crops. Integrated Pest Management (IPM) is a very common strategy. The white mold produced by Sclerotinia sclerotiorum (Lib.) causes considerable damage to bean crops. This fungus is a soil inhabitant, the symptoms of which are characterized by water-soaked lesions covered by a white cottony fungal growth on the soil surface and/or the host plant. Possible biological control agents taken from plants are being investigated as phytopathogen inhibitors. These are endophytic microorganisms that inhabit the intercellular spaces of vegetal tissues and are often responsible for antimicrobial production. The objective of the present study was to select endophytic fungi isolated from comfrey (Symphytum officinale L.) leaves with in vitro antagonist potential against the phytopathogenic fungus S. sclerotiorum. Twelve isolates of endophytic fungi and a pathogenic strain of S. sclerotiorum were used in the challenge method. With the aid of this method, four endophytes with the best antagonistic activity against S. sclerotiorum were selected. Pathogen growth inhibition zones were considered indicative of antibiosis. The percentages of pathogenic mycelia growth were measured both with and without the antagonist, resulting in growth reductions of 46.7% to 50.0% for S. sclerotiorum. These analyses were performed by evaluating the endophytic/pathogenic mycelia growth in mm/day over an eight-day period of antagonistic tests. PMID:24031320

  5. The experimental study of 32P-colloid perfusion therapy in the animal-models of chronic maxillary sinusitis

    International Nuclear Information System (INIS)

    Objective: To search for the mechanism of 32P-colloid perfusion therapy in the animal models of chronic maxillary sinusitis. Methods: 32P-colloid were injected into the male sheep maxillary sinuses of the animal-models of chronic maxillary sinusitis in different dosage group. The changes of bacteria and mucosael pathomorphology were observed by periodic germiculture and pathology in 1,3,6 months after injection. Results: After 32P-colloid perfusion therapy, the amounts of bacterial species and chronic phlogistic cells were remarkable reduced, and the structure of cilia cells did not change. The curable rate was 83.3% in 6 months. There were remarkable difference in groups. Conclusions: 32P-colloid was provided with antibiosis and reducing chronic phlogistic responses. The authors had found the optimal dose of 32P-colloid perfusion in the maxillary sinuses through the study. The curable rate of single dose of 32P-colloid perfusion in the maxillary sinuses was higher than other therapy, 32P-colloid perfusion was simple and convenient. There was high selectivity of 32P in the target organ, when there was no effect on other important organs through radiobiological measurement. (authors)

  6. Role of killer factors in the inhibitory activity of bio-control yeasts against Penicillium expansum and Aspergillus ochraceus

    Directory of Open Access Journals (Sweden)

    Ciro da Silva Portes

    2013-08-01

    Full Text Available This work evaluated the antagonism of killer positive yeast strains (isolated from 11 samples of different frozen fruit pulps against the strains of Penicillium expansum and Aspergillus ochraceus. Of the total 41 killer yeasts tested in YM agar, 19 showed antibiosis against P. expansum and A. ochraceus, with inhibition zone ranging from 10 to 18 mm and 10 to 19 mm, respectively. In the following step, the extracellular activity of Kluyveromyces sp. FP4(13 was tested performing the assay in YM broth. The antifungal activity of Kluyveromyces sp. FP4(13 cell-free culture supernatant (25ºC/96 h was more effective against the conidia germination, showing inhibition rates of 93.33 and 86.44% for P. expansum and A. ochraceus, respectively. The micelial growth inhibition was 28.45 and 21.0%, respectively. The antagonism showed by the selected yeasts could be used as a promising alternative tool to reduce and control the postharvest fungal spoilage of the fruits. However, further studies should be carried out in order to better elucidate the role of innocuous characters in antagonistic microorganisms, as well as the purification and characterization of new killer toxins.

  7. Isolation and identification of actinomyce strain MY-4 and its antagonistic activity against pathogenic fungi of fruits and vegetables%拮抗放线菌MY一4的分离、鉴定及其对果蔬病原菌的抑制作用

    Institute of Scientific and Technical Information of China (English)

    罗建军; 李辉; 耿鹏; 胡美英

    2012-01-01

    [Objective] The purpose of the study is to identify the antagonistic actinomyce strain MY-4 isolated from the surface of Shatang mandarin, and to evaluate the application potential of the strain for the biocontrol of fruit and vegetable diseases. [Method] The taxonomic identification of the strain was carried out based on the morphology, physio-biochemical characteristics and the 16S rDNA sequence analysis, and the antagonistic activity of strain MY-4 was determined by confronting incubation on the PDA plates and the mycelium growth rate method. [Result] Strain MY-4 was identified as Streptomyces albtdus. The results showed that strain MY-4 and its cell-free fermentation filtrate exhibited extensive antagonistic ef- fect on 16 fruit and vegetable pathogenic fungi. The strain exhibited the strongest antibiosis capacity with an inhibitory zone up to 17.08 mm against mycelia growth of Colletotrichum musae. Meanwhile, its culture filtrate showed the strongest antibiosis capacity against Penicillium digitatum and reduced mycelium growth by up to 98.82%. [Conclusion] These findings show that Streptomyces albulus strain MY-4 has high activity, broad antifungal spectrum, and is expected to develop into a new biocontrol agent.%【目的】为了鉴定从沙糖橘果实表面分离得到的拮抗放线菌株MY-4,并确定该菌株对果蔬病原菌的拮抗作用,【方法】采用分析MY-4形态学、生理生化特性及16SrDNA序列相似性方法以确定其分类地位,并采用平板对峙培养法和生长速率法测定了其抑菌活性。【结果】结果显示,菌株MY-4为小白链霉菌(Streptomyces albus Routien),菌株MY-4及其无菌发酵液对供试16种果蔬病原真菌均具有拮抗作用,其中菌株MY-4对香蕉炭疽病菌的拮抗作用最强.平板抑菌带宽度达17.08mm,无菌发酵液对柑橘绿霉病菌的拮抗作用最强,菌丝生长抑制率高达98.82%,【结论】小自链霉菌菌株MY-4具有活性高

  8. Compatibilidad de Trichoderma harzianum Rifai con fungicidas del arroz y su efecto sobre tres fitopatógenos fúngicos

    Directory of Open Access Journals (Sweden)

    Manuel Francisco Rodríguez Saldaña

    2016-04-01

    Full Text Available Resumen La investigación se realizó en el Laboratorio Provincial de Sanidad Vegetal en Camagüey, en la etapa comprendida de septiembre de 2013 a septiembre de 2015, en condiciones in vitro donde se determinó la compatibilidad y capacidad antagónica frente a pesticidas usados en el arroz, de Trichoderma harzianum Rifai cepa A-34 sobre los patógenos del arroz (Bipolaris oryzae Breda de Haan, Saracladium oryzae (Sawada w. Gams & D.Hawksworth y Magnaporthe grisea (Hebert Barr. Las evaluaciones mediante métodos tradicionales de aislamiento microbiológico del crecimiento micelial, la esporulación y la germinación conidial del antagonista para determinar si ejerce los mecanismos de acción de antibiosis, competencia, y parasitismo ante los patógenos fúngicos se efectuaron a partir desde las 24 hasta las 216 horas empleando. Para el análisis estadístico se empleó un diseño bifactorial en el cultivo dual, además de las escalas para la determinación de la capacidad antagónica de los microorganismos. Los ingredientes activos tebuconazol + procloraz, trifloxistrobin+ ciproconazol, y epoxiconazol + kresoxim- metil, afectaron el crecimiento micelial del antagonista, por otra parte el antagonista frente a los ingredientes activos carbendazim, oxicloruro de cobre, azoxistrobina y tebuconazol + triadimenol tuvo crecimiento micelial, esporulación e interacción con los patógenos afectándose el crecimiento de los mismos a través de los mecanismos de acción de enrollamiento, penetración, granulación , y lisis celular desde las 96 hasta las 216 horas. Trichoderma harzianum Rifai compatibility with fungicides and its effect on three fungal plant rice pathogens. ABSTRACT The research was conducted at the Provincial Laboratory of Plant Protection in Camagüey, in the fall period September 2013 to September 2015, under in vitro conditions where compatibility and antagonistic capacity was determined against used in rice pesticides, Trichoderma

  9. The Efficiency of Trichoderma harzianum and Aneurinobacillus migulanus in the Control of Gladiolus Corm Rot in Soil-Less Culture System

    Directory of Open Access Journals (Sweden)

    Nosir Walid

    2010-01-01

    Full Text Available Problem statement: Gladiolus is cultivated commonly for cut flower production, frequently as a protected crop. The glasshouse or polytunnel environment, providing excellent conditions for flower production, also make conditions more favorable for disease to develop. Approach: The pathogen Fusarium oxysporum f. sp. gladioli causes wilt diseases in a wide range of economically important plants and can have devastating effects on crop production. Trichoderma harzianum and Aneurinobacillus migulanus were tested separately and in combination for controlling F. oxysporum f. sp. gladioli activity in soilless culture using Perlite as the substrate. Results: The efficiency of both of antagonists against corm rot was evaluated based on vegetative and root growth parameters and on flowering parameters. T. harzianum was more effective than A. migulanus in disease suppression and also enhanced plant growth, increased flower production and quality. A. migulanus enhanced plant growth when tested alone. The mixture of antagonists reduced the efficiency of T. harzianum. Numbers of T. harzianum CFU in the substrate and on corms increased following application compared with treating with both antagonists. No T. harzianum was detected in the substrate by 120 day after planting, however, A. migulanus CFU significantly decreased on corms when inoculated in combination with T. harzianum and F. oxysporum f. sp. gladioli. However, A. migulanus CFU was not detected in the substrate of the same combination. SEM and Glasshouse results suggested that suppressive mechanisms of T. harzianum and A. migulanus differed. T. harzianum appeared to operate through a combination of antibiosis and substrate competition, whereas A. migulanus produced an electron-dense substance which may have inhibited the penetration of host tissues by F. oxysporum f. sp. gladiolus. Greater growth of T. harzianum was observed when inoculated alone or with F. oxysporum f. sp

  10. In vitro interaction studies between Glomus intraradices and Armillaria mellea in vines

    Energy Technology Data Exchange (ETDEWEB)

    Nogales, A.; Camprubi, A.; Estaun, V.; Marfa, V.; Calvet, C.

    2010-07-01

    An interaction study was performed with mycorrhizal plants of the grapevine rootstock Richter 110 (Vitis berlandieri Planch x Vitis rupestris Scheele) and the root pathogenic fungus Armillaria mellea (Vahl:Fr.) P. Kumm using an autotrophic in vitro culture system. Micro propagated plant lets were transferred to Petri plates with MSR medium lacking sugar and vitamins. Inocula of Glomus intraradices (BEG 72) and of Armillaria mellea obtained from a root organ culture and from a mycelium colony grown in malt agar respectively, were added to the plates according to each treatment: non-inoculated, inoculated with G. intra radices, inoculated with A. mellea, and dual-inoculated plants. There were ten replicates per treatment. Fourteen weeks later, the pathogen's mycelium occupied most of the surface/volume of the plate and had produced rhizomorphs. In dual inoculated plates, A. mellea's growth was not affected by the presence of G. intraradices, but the latter produced a lower number of spores and its extra radical phase showed granulation, vacuolation and tip swelling. The pathogen induced necrosis and growth decrease in the root. Glomus intra radices alleviated these symptoms and there were no differences in root biomass between non-inoculated plants and plants inoculated with both fungi. There were no symptoms of the disease in shoots and G. intra radices stimulated shoot growth both, although mycorrhizal colonization was lower when A. mellea was present. No direct antagonism or antibiosis against the pathogen was observed, thus the protective effect exerted by the symbiotic fungus in grapevines must be indirect, mediated through the host plant physiology. (Author) 38 refs.

  11. Functional role of bacteria from invasive Phragmites australis in promotion of host growth

    Science.gov (United States)

    Soares, M. A.; Li, H-Y; Kowalski, Kurt P.; Bergen, M.; Torres, M. S.; White, J. F.

    2016-01-01

    We hypothesize that bacterial endophytes may enhance the competitiveness and invasiveness of Phragmites australis. To evaluate this hypothesis, endophytic bacteria were isolated from P. australis. The majority of the shoot meristem isolates represent species from phyla Firmicutes, Proteobacteria, and Actinobacteria. We chose one species from each phylum to characterize further and to conduct growth promotion experiments in Phragmites. Bacteria tested include Bacillus amyloliquefaciens A9a, Achromobacter spanius B1, and Microbacterium oxydans B2. Isolates were characterized for known growth promotional traits, including indole acetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis activity. Potentially defensive antimicrobial lipopeptides were assayed for through application of co-culturing experiments and mass spectrometer analysis. B. amyloliquefaciens A9a and M. oxydans B2 produced IAA. B. amyloliquefaciens A9a secreted antifungal lipopeptides. Capability to promote growth of P. australis under low nitrogen conditions was evaluated in greenhouse experiments. All three isolates were found to increase the growth of P. australis under low soil nitrogen conditions and showed increased absorption of isotopic nitrogen into plants. This suggests that the Phragmites microbes we evaluated most likely promote growth of Phragmites by enhanced scavenging of nitrogenous compounds from the rhizosphere and transfer to host roots. Collectively, our results support the hypothesis that endophytic bacteria play a role in enhancing growth of P. australis in natural populations. Gaining a better understanding of the precise contributions and mechanisms of endophytes in enabling P. australis to develop high densities rapidly could lead to new symbiosis-based strategies for management and control of the host.

  12. Functional Role of Bacteria from Invasive Phragmites australis in Promotion of Host Growth.

    Science.gov (United States)

    Soares, M A; Li, H-Y; Kowalski, K P; Bergen, M; Torres, M S; White, J F

    2016-08-01

    We hypothesize that bacterial endophytes may enhance the competitiveness and invasiveness of Phragmites australis. To evaluate this hypothesis, endophytic bacteria were isolated from P. australis. The majority of the shoot meristem isolates represent species from phyla Firmicutes, Proteobacteria, and Actinobacteria. We chose one species from each phylum to characterize further and to conduct growth promotion experiments in Phragmites. Bacteria tested include Bacillus amyloliquefaciens A9a, Achromobacter spanius B1, and Microbacterium oxydans B2. Isolates were characterized for known growth promotional traits, including indole acetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis activity. Potentially defensive antimicrobial lipopeptides were assayed for through application of co-culturing experiments and mass spectrometer analysis. B. amyloliquefaciens A9a and M. oxydans B2 produced IAA. B. amyloliquefaciens A9a secreted antifungal lipopeptides. Capability to promote growth of P. australis under low nitrogen conditions was evaluated in greenhouse experiments. All three isolates were found to increase the growth of P. australis under low soil nitrogen conditions and showed increased absorption of isotopic nitrogen into plants. This suggests that the Phragmites microbes we evaluated most likely promote growth of Phragmites by enhanced scavenging of nitrogenous compounds from the rhizosphere and transfer to host roots. Collectively, our results support the hypothesis that endophytic bacteria play a role in enhancing growth of P. australis in natural populations. Gaining a better understanding of the precise contributions and mechanisms of endophytes in enabling P. australis to develop high densities rapidly could lead to new symbiosis-based strategies for management and control of the host.

  13. 中药双黄补对牙周病防治机制研究进展%Research progress of mechanism of Shuanghuangbu in prevention and control of periodontal diseases

    Institute of Scientific and Technical Information of China (English)

    于金兵

    2012-01-01

    Shuanghuangbu is the compatibility of three kinds of traditional Chinese medicine, which plays curative effects in promotion of periodontal tissue regeneration and repair, inhibition of inflammatory response, antibiosis, antiendotoxin and other aspects. Among the three kinds of medicine, scutellaria and cuptis have more significant anti-inflammatory and antibacterial effects while drynaria can better promote the repair and regeneration of periodontal tissues. The three kinds of medicine supplement each other and take combined effects in promoting the healing of periodontal diseases. In addition, because they are natural medicine and have no obvious toxic and side effects, they are more acceptable to patients. Developing and formulating various formulations from Shuanghuangbu and applying them to prevention of periodontal diseases or using them as the adjuvant medicine of periodontal basic treatment through various pathways have broad application prospects.%双黄补由三种中药配伍制成,从促进牙周组织再生修复、抑制炎症反应、抗菌及抗内毒素等多方面发挥治疗效果,其中黄芩和黄连具有更明显的抗炎、抗菌作用,而骨碎补具有更好地促进牙周组织修复与再生的作用.三种药物相辅相成、联合作用,促进牙周病患者的痊愈,且因其是天然药物,无明显毒副作用,更易被患者接受.将双黄补开发、研制成各种剂型,通过不同作用途径用于防治牙周病或作为牙周基础治疗的辅助用药,具有广阔的应用前景.

  14. Induction of systemic resistance in tomato by the autochthonous phylloplane resident Bacillus cereus Indução de resistência sistêmica em tomateiro pela bactéria autóctone residente no filoplano Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Bernardo de Almeida Halfeld-Vieira

    2006-08-01

    Full Text Available The objective of this work was to verify if the induced resistance mechanism is responsible for the capacity of a phylloplane resident bacteria (Bacillus cereus, isolated from healthy tomato plants, to control several diseases of this crop. A strain of Pseudomonas syringae pv. tomato was used as the challenging pathogen. The absence of direct antibiosis of the antagonist against the pathogen, the significant increase in peroxidases activity in tomato plants exposed to the antagonist and then inoculated with the challenging pathogen, as well as the character of the protection, are evidences wich suggest that biocontrol efficiency presented by the antagonist in previous works might be due to induced systemic resistance (ISR.O objetivo deste trabalho foi investigar se o mecanismo de indução de resistência é responsável pela capacidade de um isolado bacteriano residente no filoplano (Bacillus cereus, obtido de plantas sadias de tomateiro, em controlar diversas doenças da cultura. A fim de investigar o modo de ação envolvido no controle, foi utilizado um isolado de Pseudomonas syringae pv. tomato como patógeno desafiador. A ausência do mecanismo de antibiose contra o patógeno, o aumento significativo dos níveis de peroxidases em plantas expostas ao antagonista e submetidas à inoculação do patógeno desafiador, assim como a sistemicidade da proteção, são evidências que sugerem que o mecanismo de biocontrole em questão se refere à indução de resistência sistêmica (IRS.

  15. Methods to Test Antimicrobial Properties and Application in Leather Industry%抗菌性能的检测方法及其在皮革行业中的应用(续)

    Institute of Scientific and Technical Information of China (English)

    唐秋月; 陈武勇

    2013-01-01

    Some frequently - used testing methods on antimicrobial properties for antibacterial product were reviewed. First, these methods were classified and compared with each other. Then the advantages, disadvantages and the feasibilities in leather were commented. Based on these, the hallo method and seed - ager under given circumstances method were proposed to test the antimicrobial properties of the soluble leather products; and the shake flask method and quinn method were proposed to test the antimicrobial properties of the insoluble leather products. Also, antibiosis is not sterilization, so the method proposed to test the antimicrobial properties of antibacterial product should consider human' s health.%概述了国内外用于抗菌产品抗菌抑菌性能测试的常用方法.首先将这些方法按照一定标准进行分类,并采用分类对比的方法评述了每种方法的优缺点及其在皮革行业中应用的可行性,在此基础上提出了对皮革抗菌抑菌性能的测试方法建议,即溶出性抗菌产品采用琼脂平皿扩散法和晕圈法,不溶出性抗菌产品采用振荡法和奎因法.最后,考虑到安全性等问题,提出了抗菌并不是消毒,在选择测试方法时,还应与人体健康密切联系.

  16. Methods to Test Antimicrobial Properties and Application in Leather Industry%抗菌性能的检测方法及其在皮革行业中的应用

    Institute of Scientific and Technical Information of China (English)

    唐秋月; 陈武勇

    2013-01-01

    Some frequently - used testing methods on antimicrobial properties for antibacterial product were reviewed. First, these methods were classified and compared with each other. Then the advantages, disadvantages and the feasibilities in leather were commented. Based on these, the hallo method and seed - ager under given circumstances method were proposed to test the antimicrobial properties of the soluble leather products; and the shake flask method and quinn method were proposed to test the antimicrobial properties of the insoluble leather products. Also, antibiosis is not sterilization, so the method proposed to test the antimicrobial properties of antibacterial product should consider human' s health.%概述了国内外用于抗菌产品抗菌抑菌性能测试的常用方法.首先将这些方法按照一定标准进行分类,并采用分类对比的方法评述了每种方法的优缺点及其在皮革行业中应用的可行性,在此基础上提出了对皮革抗菌抑菌性能的测试方法建议,即溶出性抗菌产品采用琼脂平皿扩散法和晕圈法,不溶出性抗菌产品采用振荡法和奎因法.最后,考虑到安全性等问题,提出了抗菌并不是消毒,在选择测试方法时,还应与人体健康密切联系.

  17. 秦岭沙参属药用植物资源及利用%Investigation and Utilization of Germplasm Resources of Adenophora Plants in Qinling Mountains

    Institute of Scientific and Technical Information of China (English)

    贺游利

    2011-01-01

    A. is a kind of traditional Chinese medicine that works efficient in nourishing yin and clearing lung-heat,dissolving phlegm and relieving cough. The survey results show there are 20 species of A. plants in Qinling Mountains, among which 12 species can be medicine. A.is rich in polysaccharides, terpenoid, sterol, fatty acid, amino acid, trace element, phospholipid and so on, which plays a important role in antibiosis, anti-radiation, anti-tumor and regulating immune system. The wild resources of A. were classified and analyzed in this study, so as to provide theoretical basis for the reasonable exploitation and utilization of A. resources in Qinling Mountains.%沙参(RADIX ADENOPHORAE)是著名的养阴清肺、镇咳祛痰的中草药.秦岭约有沙参属植物资源20余种,其中药用的有12种.沙参富含多糖、甾体、三萜、脂肪酸、氨基酸、微量元素和磷脂等成分,在镇咳、祛痰、抗辐射、抗肿瘤和提高免疫调节功能等方面具有明显的临床效果.对秦岭野生沙参属植物资源进行了归类和分析,为合理开发利用这一植物资源提供理论依据.

  18. Endophyte isolate and host grass effects on Chaetocnema pulicaria (Coleoptera: Chrysomelidae) feeding.

    Science.gov (United States)

    Ball, Olivier J P; Gwinn, Kimberly D; Pless, Charles D; Popay, Alison J

    2011-04-01

    Endophytic fungi belonging to the genus Neotyphodium, confer resistance to infected host grasses against insect pests. The effect of host species, and endophtye species and strain, on feeding and survival of the corn flea beetle, Chaetocnema pulicaria Melsheimer (Coleoptera: Chrysomelidae) was investigated. The grass-endophyte associations included natural and artificially derived associations producing varying arrays of common endophyte-related alkaloids or alkaloid groups, peramine, lolitrem B, ergovaline, and the lolines. Preference and nonpreference tests showed that C. pulicaria feeding and survival were reduced by infection of tall fescue with the wild-type strain of N. coenophialum, the likely mechanism being antixenosis rather than antibiosis. In the preference tests, endophyte and host species effects were observed. Of the 10 different Neotyphodium strains tested in artificially derived tall fescue associations, eight strongly deterred feeding by C. pulicaria, whereas the remaining two strains had little or no effect on feeding. Infection of tall fescue with another fungal symbiont, p-endophyte, had no effect. Perennial ryegrass, Lolium perenne L., infected with six strains of endophyte, was moderately resistant to C. pulicaria compared with endophyte-free grass, but four additional strains were relatively inactive. Six Neotyphodium-meadow fescue, Festuca pratensis Huds., associations, including the wild-type N. uncinatum-meadow fescue combination, were resistant, whereas three associations were not effective. Loline alkaloids seemed to play a role in antixenosis to C. pulicaria. Effects not attributable to the lolines or any other of the alkaloids examined also were observed. This phenomenon also has been reported in tests with other insects, and indicates the presence of additional insect-active factors.

  19. Screening and modes of action of antagonistic bacteria to control the fungal pathogen Phaeomoniella chlamydospora involved in grapevine trunk diseases.

    Science.gov (United States)

    Haidar, Rana; Roudet, Jean; Bonnard, Olivier; Dufour, Marie Cécile; Corio-Costet, Marie France; Fert, Mathieu; Gautier, Thomas; Deschamps, Alain; Fermaud, Marc

    2016-11-01

    The antagonistic activity of 46 bacterial strains isolated from Bordeaux vineyards were evaluated against Phaeomoniella chlamydospora, a major grapevine pathogen involved in Esca. The reduction of the necrosis length of stem cuttings ranged between 31.4% and 38.7% for the 8 most efficient strains. Two in planta trials allowed the selection of the two best strains, Bacillus pumilus (S32) and Paenibacillus sp. (S19). Their efficacy was not dependent on application method; co-inoculation, prevention in the wood and soil inoculation were tested. The involvement of antibiosis by the secretion of diffusible and/or volatile compounds in the antagonistic capacity of these two strains was assessed in vitro. Volatile compounds secreted by B. pumilus (S32) and Paenibacillus sp. (S19) were identified by gas chromatography/mass spectroscopy (GC/MS). The volatile compounds 1-octen-3-ol and 2,5-dimethyl pyrazine were obtained commercially and tested, and they showed strong antifungal activity against P. chlamydospora, which suggested that these compounds may play an important role in the bacterial antagonistic activity in planta. Furthermore, the expression of 10 major grapevine defense genes was quantified by real-time polymerase chain reaction, which demonstrated that the two strains significantly affected the grapevine transcripts four days after their application on the plants. High expression levels of different genes associated with P. chlamydospora infection in B. pumilus pre-treated plants suggests that this strain induces systemic resistance in grapevine. For the first time, we demonstrated the ability of two bacterial strains, B. pumilus and Paenibacillus sp., isolated from grapevine wood, to control P. chlamydospora via direct and/or indirect mechanisms. PMID:27664735

  20. Resistance of soybean genotypes to Bemisia tabaci (Genn.) Biotype B (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Vieira, S S; Bueno, A F; Boff, M I C; Bueno, R C O F; Hoffman-Campo, C B

    2011-01-01

    The silverleaf whitefly Bemisia tabaci (Genn.) biotype B has become a serious problem for soybean cultivation because it can significantly reduce soybean productivity. The use of soybean cultivars resistant to whitefly attack is an important strategy in an integrated pest management (IPM) program. This study evaluated the preference for oviposition and colonization by B. tabaci biotype B on different soybean genotypes. In the free-choice test, the genotypes studied were 'IAC 17' and 'IAC 19' as the standards for resistance and 'IAC Holambra Stwart' as the standard for susceptibility, as well as BABR01-0492, BABR01-0173, BABR01-1259, BABR01-1576, BABR99-4021HC, BABR99-4021HP, 'Barreiras', 'Conquista', 'Corisco', 'BRS Gralha', PI274454, PI227687, and PI171451. In the no-choice test, the four best genotypes selected in the free-choice test, in addition to the susceptible and resistant standards were evaluated. Our data indicated 'Barreiras' as the most resistant genotype against B. tabaci biotype B. 'BRS Gralha', which was the least attractive to whitefly adults in the free-choice test, did not show resistance to insect attack when they were confined in cages in the no-choice test. Despite the high number of eggs observed, BABR01-1576 and BABR99-4021HC showed a reduced number of nymphs, indicating antibiosis. The genotypes with a high level of resistance can be used as a tool against B. tabaci in IPM or as a source of resistance in plant-breeding programs.

  1. 熟制配菜的杀菌和防腐剂复配研究%Study on Sterilization and Preservative Compound of Processed Vegetable

    Institute of Scientific and Technical Information of China (English)

    于宁; 张慜; 王建清

    2012-01-01

    In this study, the optimum formula of the processed vegetable for the best sensory e-valuation was investigated, and listed as follows: : carrot 10%, garlic sprout 17%, lettuce 23%, bean curd 5%, pickled cucumbers 10%, soybean oil 1.5%, salt 0.7%. Furthermore, the antibiosis effect of Nisin and potassium sorbate on the precessed vegetable was studied, which can extend the field of controlling the bacteria, reduce sterilization intensity and the loss of flavor substance. The result shows that: the bacteria can be controlled effectively when the concentration of Nisin and potassium sorbate were 0. 08 g/kg and 0. 30 g/kg, sterilization conditions reduced to 85℃ for l0min.%研究了熟制配菜中主要原料的配比关系,即当胡萝卜10%、蒜苔17%、莴苣23%、千张5%、酱瓜10%、大豆油1.5%、食盐0.7%时,产品的感官评价最高.另外,还研究了乳酸链球菌素(Nisin)与山梨酸钾在熟制配菜中的复配抑菌作用,二者的复配可扩大抑菌范围,从而降低杀菌强度,减少风味物质的损失.结果表明,当Nisin、山梨酸钾的浓度分别为0.08、0.30g/kg时,杀菌条件为85℃、10 min,可有效抑制微生物的生长.

  2. Resistência de cultivares de videira ao ácaro-rajado Tetranychus urticae na região de Jales, estado de São Paulo Vine cultivars resistance to twospotted spider mite Tetranychus urticae koch in the region of Jales, state of São Paulo

    Directory of Open Access Journals (Sweden)

    Gisele Santos Valadão

    2012-12-01

    Full Text Available As videiras da região de Jales, Estado de São Paulo, têm sido intensamente atacadas pelo ácaro-rajado, Tetranychus urticae Koch. O presente trabalho teve por objetivo comparar cultivares de uva quanto à adequação como hospedeiras da espécie. Em experimento de campo, naquele local, a ocorrência da praga, ao longo de 12 meses, foi acompanhada nas cultivares de uvas finas, Itália e Benitaka, e na cultivar de uva rústica, Niagara Rosada. No laboratório, a biologia de T. urticae foi estudada nessas três cultivares e na 'Redimeire'. Na cultivar Niagara Rosada, o ácaro-rajado apresentou menor fecundidade e menor sobrevivência, indicando a presença de mecanismos de resistência por antibiose. Além disso, houve maior tentativa de fuga dessa cultivar, sugerindo resistência por não preferência.In the region of Jales, the vines has been heavily attacked by the twospotted spider mite, Tetranychus urticae Koch. The objective of this study was to compare grape cultivars for suitability as hosts of the species. In field experiment at that location, the pest occurrence, over 12 months, was accompanied on fine grape cultivars, Italy and Benitaka, and rustic grape cultivar, Niagara Rosada. In the laboratory, the T. urticae biology was carried out on these three cultivars and in the 'Redimeire'. Twospotted spider mite presented lower fertility and lower survival on Niagara Rosada cultivar indicating the presence of antibiosis resistance mechanisms. In addition, there was a greater attempt to escape in this cultivar, suggesting a resistance for non-preference.

  3. Vacuum-assisted closure in the treatment of early hip joint infections

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    Jens Kelm, Eduard Schmitt, Konstantinos Anagnostakos

    2009-01-01

    Full Text Available The aim of the present study was to evaluate the efficacy of the vacuum-assisted closure (V.A.C. system in the treatment of early hip joint infections. 28 patients (11 m / 17 f; mean age 71 y. [43-84] with early hip joint infections have been treated by means of the V.A.C.-therapy. At least one surgical revision [1-7] has been unsuccessfully performed for infection treatment prior to V.A.C. - application. Pathogen organisms could have been isolated in 22/28 wounds. During revision, cup inlay and prosthesis head have been exchanged and 1-3 polyvinylalcohol sponges inserted into the wound cavity/ periprosthetically at an initial continuous pressure of 200 mm Hg. Postoperatively, a systemic antibiosis was given according to antibiogram. 48-72 h after surgery an alteration from haemorrhagic to serous fluid was observed in the V.A.C.-canister. Afterwards, the pressure was decreased to 150 mm Hg and remained at this level till sponge removal. After a mean period of 9 [3-16] days the inflammation parameters have been retrogressive and the sponges were removed. An infection eradication could be achieved in 26/28 cases. In the two remaining cases the infected prosthesis had to be explanted and a gentamicin-vancomycin-loaded spacer has been implanted, respectively. At a total mean follow-up of 36 [12-87] months no reinfection or infection persistence was observed. The V.A.C.-system can be a valuable contribution in the treatment of early joint infections when properly used. Indications should be early infections with well-maintained soft-tissues for retention of the negative atmospheric pressure.

  4. The microbe-free plant: fact or artefact?

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    Laila P. Pamela Partida-Martinez

    2011-12-01

    Full Text Available Plant-microbe interactions are ubiquitous. Plants are often colonized by pathogens but even more commonly engaged in neutral or mutualistic interactions with microbes: below-ground microbial plant associates are mycorrhizal fungi, Rhizobia and rhizosphere bacteria, above-ground plant parts are colonized by bacterial and fungal endophytes and by microbes in the phyllosphere. We emphasize here that a completely microbe-free plant is an exotic exception rather than the biologically relevant rule. The complex interplay of such microbial communities with the host plant affects plant nutrition, growth rate, resistance to biotic and abiotic stress, and plant survival and distribution. The mechanisms involved reach from nutrient acquisition, the production of plant hormones or direct antibiosis to effects on host resistance genes or interactions at higher trophic levels. Plant-associated microbes are heterotrophic and cause costs to their host plant, whereas the benefits depend on the environment. Thus, the outcome of the interaction is highly context-dependent. Considering the microbe-free plant as the ‘normal’ or control stage significantly impairs research into important phenomena such as (1 phenotypic and epigenetic plasticity, (2 the ‘normal’ ecological outcome of a given interaction and (3 the evolution of plants. For the future, we suggest cultivation-independent screening methods using direct PCR from plant tissue of more than one fungal and bacterial gene to collect data on the true microbial diversity in wild plants. The patterns found could be correlated to host species and environmental conditions, in order to formulate testable hypotheses on the biological roles of plant endophytes in nature. Experimental approaches should compare different host-endophyte combinations under various environmental conditions and study at the genetic, transcriptional and physiological level the parameters that shift the interaction along the mutualism

  5. Induced Resistance as a Mechanism of Biological Control by Lysobacter enzymogenes Strain C3.

    Science.gov (United States)

    Kilic-Ekici, Ozlem; Yuen, Gary Y

    2003-09-01

    ABSTRACT Induced resistance was found to be a mechanism for biological control of leaf spot, caused by Bipolaris sorokiniana, in tall fescue (Festuca arundinacea) using the bacterium Lysobacter enzymogenes strain C3. Resistance elicited by C3 suppressed germination of B. sorokiniana conidia on the phylloplane in addition to reducing the severity of leaf spot. The pathogen-inhibitory effect could be separated from antibiosis by using heat-inactivated cells of C3 that retained no antifungal activity. Application of live or heat-killed cells to tall fescue leaves resulted only in localized resistance confined to the treated leaf, whereas treatment of roots resulted in systemic resistance expressed in the foliage. The effects of foliar and root applications of C3 were long lasting, as evidenced by suppression of conidial germination and leaf spot development even when pathogen inoculation was delayed 15 days after bacterial treatment. When C3 population levels and germination of pathogen conidia was examined on leaf segments, germination percentage was reduced on all segments from C3-treated leaves compared with segments from non-treated leaves, but no dose-response relationship typical of antagonism was found. Induced resistance by C3 was not host or pathogen specific; foliar application of heat-killed C3 cells controlled B. sorokiniana on wheat and also was effective in reducing the severity of brown patch, caused by Rhizoctonia solani, on tall fescue. Treatments of tall fescue foliage or roots with C3 resulted in significantly elevated peroxidase activity compared with the control.

  6. The SRAP based molecular diversity related to antifungal and antioxidant bioactive constituents for biocontrol potentials of Trichoderma against Sclerotium rolfsii Scc.

    Science.gov (United States)

    Hirpara, Darshna G; Gajera, H P; Bhimani, R D; Golakiya, B A

    2016-08-01

    The study was performed to examine 11 isolates of Trichoderma for their bio-control potentials against Sclerotium rolfsii Sacc. causing stem rot in groundnut. The antagonists Trichoderma were subjected to sequence related amplified polymorphism (SRAP) based molecular diversity analysis and compared with their hardness to S. rolfsii with respect to secretary antifungal and antioxidant profile. T. virens NBAII Tvs 12 evident highest (87.91 %) growth inhibition of test pathogen followed by T. koningii MTCC 796 (67.03 %) at 7 days after inoculation (DAI). Microscopic study confirmed biocontrol mechanism as mycoparasitism for Tvs 12 and antibiosis for MTCC 796. The growth inhibition of test pathogen was significantly negatively correlated with sclerotia formation and lipid peroxidation during antagonism due to release of secretary bioactive antioxidants by antagonists to terminate oxidative burst generated by S. rolfsii and causing inhibition of sclerotium formation. The GC-MS profile identified antifungal and antioxidant constituents hexadecane, 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester, 1-hexadecanesulfonyl chloride, and octadecane in potent antagonists Tvs 12; and nonacosane and octadecane in MTCC 796 along with two novel compounds 1-pentadecene and 1-heneicosyl formate for biocontrol activity. Molecular diversity of Trichoderma isolates associated with antagonistic activity was assessed by SRAP markers. The 115 primer combinations generate total 1328 amplified products of which, 1095 are shared polymorphic and 199 are unique polymorphic. The 15 SRAP combinations produced 18 bands to diagnose best antagonist Tvs 12 and 13 SRAP combinations generated 19 unique bands for identification of MTCC 796. The mycoparasitic antagonist Tvs 12 would be the best antagonist and released unique antifungal and antioxidant constituents to combat pathogen infection. The SRAP based genetic diversity indicates Tvs12 strain clustered with T. viride NBAII Tv23 and shared

  7. 苹果果胶研究进展%Research progress of apple pectin

    Institute of Scientific and Technical Information of China (English)

    孙立军; 郭玉蓉; 田兰兰

    2012-01-01

    苹果(Malus pumila Mill.)是我国北方广泛种植的经济作物。近年来,很多学者从苹果渣中提取分离得到苹果果胶。现代医学和生物学研究表明,苹果果胶具有抗氧化、降血脂、抗菌及抗癌的功效。本文介绍了苹果果胶的结构、组分分级与特性研究,着重阐述了目前国内外对于苹果果胶的提取、分离的最新进展及其生物活性,讨论了目前研究中存在的问题,并对其发展前景进行了展望。%Apple(Malus pumila Mill.) tree is a common kind of plant in the northern part of our country.In recent years,apple pectin has been isolated from apple pomace by many researchers.Researchers in medicine and biology have proved that apple pectin has many biology activities such as oxidation resistance,hypolipemic,antibiosis and anticancer.In this review,structure of apple pectin,pectin fraction and properties of different molecular weights were reviewed and the latest methods of extraction,biological activities,problems of studies on apple pectin and its prospects were also elaborated.

  8. Resident bacteria on leaves enhance survival of immigrant cells of Salmonella enterica.

    Science.gov (United States)

    Poza-Carrion, Cesar; Suslow, Trevor; Lindow, Steven

    2013-04-01

    Although Salmonella enterica apparently has comparatively low epiphytic fitness on plants, external factors that would influence its ability to survive on plants after contamination would be of significance in the epidemiology of human diseases caused by this human pathogen. Viable population sizes of S. enterica applied to plants preinoculated with Pseudomonas syringae or either of two Erwinia herbicola strains was ≥10-fold higher than that on control plants that were not precolonized by such indigenous bacteria when assessed 24 to 72 h after the imposition of desiccation stress. The protective effect of P. fluorescens, which exhibited antibiosis toward S. enterica in vitro, was only ≈50% that conferred by other bacterial strains. Although S. enterica could produce small cellular aggregates after incubation on wet leaves for several days, and the cells in such aggregates were less susceptible to death upon acute dehydration than solitary cells (as determined by propidium iodide staining), most Salmonella cells were found as isolated cells when it was applied to leaves previously colonized by other bacterial species. The proportion of solitary cells of S. enterica coincident with aggregates of cells of preexisting epiphytic species that subsequently were judged as nonviable by viability staining on dry leaves was as much as 10-fold less than those that had landed on uncolonized portions of the leaf. Thus, survival of immigrant cells of S. enterica on plants appears to be strongly context dependent, and the presence of common epiphytic bacteria on plants can protect such immigrants from at least one key stress (i.e., desiccation) encountered on leaf surfaces. PMID:23506362

  9. Ethylene Contributes to maize insect resistance1-Mediated Maize Defense against the Phloem Sap-Sucking Corn Leaf Aphid.

    Science.gov (United States)

    Louis, Joe; Basu, Saumik; Varsani, Suresh; Castano-Duque, Lina; Jiang, Victoria; Williams, W Paul; Felton, Gary W; Luthe, Dawn S

    2015-09-01

    Signaling networks among multiple phytohormones fine-tune plant defense responses to insect herbivore attack. Previously, it was reported that the synergistic combination of ethylene (ET) and jasmonic acid (JA) was required for accumulation of the maize insect resistance1 (mir1) gene product, a cysteine (Cys) proteinase that is a key defensive protein against chewing insect pests in maize (Zea mays). However, this study suggests that mir1-mediated resistance to corn leaf aphid (CLA; Rhopalosiphum maidis), a phloem sap-sucking insect pest, is independent of JA but regulated by the ET-signaling pathway. Feeding by CLA triggers the rapid accumulation of mir1 transcripts in the resistant maize genotype, Mp708. Furthermore, Mp708 provided elevated levels of antibiosis (limits aphid population)- and antixenosis (deters aphid settling)-mediated resistance to CLA compared with B73 and Tx601 maize susceptible inbred lines. Synthetic diet aphid feeding trial bioassays with recombinant Mir1-Cys Protease demonstrates that Mir1-Cys Protease provides direct toxicity to CLA. Furthermore, foliar feeding by CLA rapidly sends defensive signal(s) to the roots that trigger belowground accumulation of the mir1, signifying a potential role of long-distance signaling in maize defense against the phloem-feeding insects. Collectively, our data indicate that ET-regulated mir1 transcript accumulation, uncoupled from JA, contributed to heightened resistance to CLA in maize. In addition, our results underscore the significance of ET acting as a central node in regulating mir1 expression to different feeding guilds of insect herbivores. PMID:26253737

  10. The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

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    De Maayer Pieter

    2012-11-01

    Full Text Available Abstract Background Pantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts. This suggests that members of this genus have undergone extensive genotypic diversification. One means by which this occurs among bacteria is through the acquisition and maintenance of plasmids. Here, we have analyzed and compared the sequences of a large plasmid common to all sequenced Pantoea spp. Results and discussion The Large PantoeaPlasmids (LPP-1 of twenty strains encompassing seven different Pantoea species, including pathogens and endo-/epiphytes of a wide range of plant hosts as well as insect-associated strains, were compared. The LPP-1 plasmid sequences range in size from ~281 to 794 kb and carry between 238 and 750 protein coding sequences (CDS. A core set of 46 proteins, encompassing 2.2% of the total pan-plasmid (2,095 CDS, conserved among all LPP-1 plasmid sequences, includes those required for thiamine and pigment biosynthesis. Phylogenetic analysis reveals that these plasmids have arisen from an ancestral plasmid, which has undergone extensive diversification. Analysis of the proteins encoded on LPP-1 also showed that these plasmids contribute to a wide range of Pantoea phenotypes, including the transport and catabolism of various substrates, inorganic ion assimilation, resistance to antibiotics and heavy metals, colonization and persistence in the host and environment, pathogenesis and antibiosis. Conclusions LPP-1 is universal to all Pantoea spp. whose genomes have been sequenced to date and is derived from an ancestral plasmid. LPP-1 encodes a large array of proteins that have played a major role in the adaptation of the different Pantoea spp. to their various ecological niches and their specialization as pathogens, biocontrol agents or benign saprophytes found in many diverse

  11. Resistance of stored bean varieties to Acanthoscelides obtectus (Coleoptera: Bruchidae)

    Institute of Scientific and Technical Information of China (English)

    Edson L.L. Baldin; Fernando M. Lara

    2008-01-01

    During bean seed storage, yield can be lost due to infestations of Acanthoscelides obtectus Say, the bean weevil. The use of resistant varieties has shown promising results in fighting these insects, reducing infestation levels and eliminating chemical residues from the beans. The expression of resistance to A. obtectus in bean varieties is frequently attributed to the presence of phytohemagglutinins, protease inhibitors and alpha-amylase, and espe-cially to variants of the protein arcelin, which reduce the larval viability of these insects. Toevaluate the effect of bean seed storage time on the resistance expression of bean varietiesto A. obtectus, tests with seeds of three ages (freshly-harvested, 4-month-old, and 8-month-old) were conducted in the laboratory, using four commercial varieties: Carioca Pitoco, Ipa 6, PorriUo 70, 0nix; four improved varieties containing arcelin protein: Arc. 1, Arc.2, Arc.3, Arc.4; and three wild varieties also containing arcelin protein: Arc.lS, Arc.3S, and Arc.5S. The Arc.5S, Arc. 1S, and Arc.2 varieties expressed high antibiosis levels against the weevil; Arc. 1 and Arc3S expressed the same mechanism, but at lower levels. The occurrence of oviposition non-preference was also observed in Arc.5S and Arc. IS. The Arc.3 and Arc.4 varieties expressed low feeding non-preference levels against A. obtectus. The expression of resistance in arcelin-bearing, wild or improved varieties was affected during the storage of seeds, and was high under some parameters but low in others. The results showed that addition of chemical resistance factors such as protein arcelin via genetic breeding may be beneficial in improving the performance of bean crops.

  12. A novel method for rapidly isolating microbes that suppress soil-borne phytopathogens

    Science.gov (United States)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2016-04-01

    Seedling establishment faces a large number of challenges related to soil physical properties as well as to fungal root diseases. It is extremely difficult to eliminate fungal pathogens from soils where their populations are established due to the persistent nature of their spores and since fumigation of resident fungi is very ineffective in clay-containing soils. Therefore it is necessary to find ways to overcome disease in areas where the soils are infected with fungal phytopathogens. The phenomenon of disease suppressive soils, where the pathogen is present but no disease observed, suggests that microbial antagonism in the soil may lead to the suppression of the growth of fungal pathogens. There are also cases in the literature where soil microorganisms were isolated that suppress the growth of phytopathogens. Antibiosis is one of the most important mechanisms responsible for fungal antagonism, with some significant antifungal compounds involved including antibiotics, volatile organic compounds, hydrogen cyanide and lytic enzymes. Isolation of pathogen-suppressive microorganisms from the soil is time consuming and tedious. We established a simple method for direct isolation of soil microbes (bacteria and fungi) that suppress fungal phytopathogens as well as procedures for confirmation of disease suppression. We will discuss such methods, which were so far tested with the cotton fungal pathogens Thielaviopsis basicola, Verticillium dahliae and Fusarium oxysporum and Verticillium fungicola. We have isolated a diversity of T. basicola-suppressive fungi and bacteria from two vastly different soil types. Identification of the antagonistic isolates revealed that they are a diverse lot, some belong to groups known to be suppressive of a wide range of fungal pathogens, endorsing the power of this technique to rapidly and directly isolate soil-borne microbes antagonistic to a wide variety of fungal pathogens.

  13. Interspecific variation in resistance of two host tree species to spruce budworm

    Science.gov (United States)

    Fuentealba, Alvaro; Bauce, Éric

    2016-01-01

    Woody plants regularly sustain biomass losses to herbivorous insects. Consequently, they have developed various resistance mechanisms to cope with insect attack. However, these mechanisms of defense and how they are affected by resource availability are not well understood. The present study aimed at evaluating and comparing the natural resistance (antibiosis and tolerance) of balsam fir (Abies balsamea [L.] Mill.) and white spruce (Picea glauca [Moench) Voss] to spruce budworm, Choristoneura fumiferana (Clem.), and how drainage site quality as a component of resource availability affects the expression of resistance over time (6 years). Our results showed that there are differences in natural resistance between the two tree species to spruce budworm, but it was not significantly affected by drainage quality. Balsam fir exhibited higher foliar toxic secondary compounds concentrations than white spruce in all drainage classes, resulting in lower male pupal mass, survival and longer male developmental time. This, however, did not prevent spruce budworm from consuming more foliage in balsam fir than in white spruce. This response suggests that either natural levels of measured secondary compounds do not provide sufficient toxicity to reduce defoliation, or spruce budworm has developed compensatory mechanisms, which allow it to utilize food resources more efficiently or minimize the toxic effects that are produced by its host's defensive compounds. Larvae exhibited lower pupal mass and higher mortality in rapidly drained and subhygric sites. Drainage class also affected the amount of foliage destroyed but its impact varied over the years and was probably influenced by climatic variables. These results demonstrate the complexity of predicting the effect of resource availability on tree defenses, especially when other confounding environmental factors can affect tree resource allocation and utilization.

  14. Aislamiento de secuencias de cisteín proteasas expresadas en la interacción Brachiaria-Salivazo

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    Roda Fornaguera Federico

    2006-12-01

    Full Text Available El ataque del salivazo induce en genotipos resistentes de Brachiaria la transcripción de un mARN que codifica
    para una proteasa de la familia de las papainas. En tres genotipos del pasto, caracterizados por presentar
    diferentes grados de resistencia al insecto, se aislaron secuencias genómicas y cDNA de homólogos a este
    transcrito, candidato a mediador de la antibiosis. Estas secuencias conforman una familia génica en la cual
    habrían ocurrido recientes eventos de duplicación (la similitud entre ellas es superior al 97%. Las proteínas que se traducirían de estos genes (BCPs presentan las características distintivas de las papainas similares a
    Catepsinas L: una señal N-terminal de translocacion al ER, un propéptido inhibitorio con los motivos ERFNIN
    y GNFD y un dominio catalítico conservado. Las BCPs forman un clado muy divergente de los demás grupos
    de papinas reportados lo cual dificulta la realización de predicciones funcionales. Sin embargo (1 la detección
    de elementos reguladores en los mARNs, (2 el hecho de que las BCPs sean apoplásticas y similares a enzimas
    de xilema, y (3 el aislamiento de una proteasa truncada que podría tener un efecto inhibitorio sobre la BCP
    expresada en el suceptible infestado, permiten proponer rutas por las que se mediaría el efecto antibiótico.

  15. Microflora en semillas de frijol

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    Jos\\u00E9 B. Membre\\u00F1o

    2001-01-01

    Full Text Available Microflora en semillas de frijol (Phaseolus vulgaris L.. Se estudió la microflora bacteriana presente en semillas de frijol y su relación con Xanthomonas campestris pv. phaseoli (Xcp, en 118 genotipos procedentes de VIDAC-98, INTA- Nicaragua, TARS-USDA e Isabela-P.R. Se utilizaron cinco métodos de aislamiento: semilla desinfectada con hipoclorito de sodio, semilla en caldo nutritivo refrigerada por una hora, dispersión de 0,1 ml de suspensión de semillas en medio sólido, siembra líquida de 1 ml de suspensión y semilla en caldo nutritivo, agitado y refrigerado por 24 horas. Se aislaron 104 colonias amarillas de 41 genotipos. Treinta y seis colonias fueron KOH positivo (Gram negativo, 68 negativo (Gram positivo y 34 hidrolizaron almidón. Las colonias de pigmentación amarilla resultaron no patogénicas bajo condiciones de invernadero. Estas se identificaron con el sistema BIOLOG como: Pantoea agglomerans (25, Xanthomonas campestris (2, Enterobacter agglomerans (2, Sphingomonas paucimobilis (2, Pseudomonas fluorescens y Flavimonas oryzihabitans. En adición, los genotipos portaron colonias con pigmentación distinta a la amarilla. En las pruebas de antagonismo se identificaron colonias con actividad de deoxyribonucleasa y de antibiosis a Xcp. De éstas, 15 colonias inhibieron a Xcp significativamente. Se identificaron los hongos Rhizoctonia solani, Penicillium spp., Fusarium spp., Aspergillus flavus, Rhizopus nigricans y Macrophomina phaseolina en un 52,9 % del total de genotipos evaluados

  16. Novel Approaches to Implementation of Pumpkin Resistance in Control of Viral Diseases

    Directory of Open Access Journals (Sweden)

    Aleksandra Bulajić

    2010-01-01

    Full Text Available As there is a growing frequency of viral plant diseases in epidemic proportions, the possibilities for successful control are constantly being explored. Despite the fact that integral and simultaneous employment of numerous control measures may contribute to thedecreasing amount of yield losses, especially concerning non-persistently aphid-transmitted viruses, these measures are often not efficient enough. Research into the basis of resistance to viral infection and principles of its inheritance, introduction of sources of resistance in susceptible genotypes, by conventional or genetic manipulations, are very intensive for cucurbit crops, especially pumpkins. Pumpkin crops are being endangered by a great number of different viruses, among which the Zucchini yellow mosaic virus, (ZYMV, Watermelon mosaic virus (WMV and Cucumber mosaic virus (CMV are present every year in Serbia, frequently causing epidemics.The majority of pumpkin cultivars are not resistant or tolerant to viral infections, but sources of resistance have been identified in various related species. So far, the identified sources of esistance to the ZYMV are found in Cucurbita moschata and Citrullus lanatus var.lanatus genotypes and consist of one or several major dominant genes of resistance. It is a similar case with WMV, although the sources of dominant major genes are identified in C. lanatus and C. colocynthis. The sources of resistance to CMV in the form of one dominant gene have been identified in the genotype C. moschata, although the introduction of this gene by conventional means proved to be very difficult. Besides the aforementioned, substantial efforts are being made in developing genotypes with multiple resistance against several viruses and even other pathogens, as well as genotypes with resistance to the most significant plant aphid species, through mechanisms of antixenosis or antibiosis. The other way of obtaining resistant genotypes includes genetic manipulation

  17. Evaluation of Resistance of Cucumber Cultivars to the Vegetable Leafminer (Liriomyza sativae Blanchard (Diptera: Agromyzidae in Greenhouse Evaluación de Resistencia de Cultivares de P epino a la Mosca Minadora (Liriomyza sativae Blanchard (Diptera: Agromyzidae en Invernadero

    Directory of Open Access Journals (Sweden)

    Moslem Basij

    2011-09-01

    Full Text Available The leafminer, Liriomyza sativae Blanchard, is distributed around the world and is an important pest of vegetables and ornamentals. Given the resistance potential of the leafminer to current insecticides, the use of resistant plant cultivars and parasitoids could be effective integrated pest management (IPM strategies against it. Cucumber (Cucumis sativus L. is a preferred host for this insect. Seventeen cultivars of cucumber have been evaluated to study resistance mechanisms to L. sativae. All cucumber cultivars were evaluated in screening tests in greenhouse with indices such as the number of leafminer stings, the number of larval mines, the proportion of larval mines to leafminer stings, and the rate of injury. Significant differences (p La mosca minadora, Liriomyza sativae Blanchard, se ha distribuido por el mundo en recientes años y es una plaga importante de vegetales y plantas ornamentales. La resistencia potencial de la mosca minadora a insecticidas corrientes, el uso de cultivares resistentes, y parasitoides podrían ser estrategias efectivas en su manejo integrado de plagas (IPM. El pepino (Cucumis sativus L. es un huésped preferido por este insecto. Diecisiete cultivares de pepino fueron evaluados para estudiar los mecanismos de resistencia a L. sativae, en pruebas de screening en invernadero usando índices tales como número de marcas hechas por la mosca, número de galerías larvales, proporción entre galerías larvales y marcas hechas por la mosca, y tasa de daño. Se observaron diferencias significativas (p < 0,01 entre cultivares, así como correlaciones significativas entre los índices evaluados. Los cultivares de pepino se clasificaron por el método cluster basado en todos los caracteres medidos en cuatro grupos: susceptible, semi susceptible, semi resistente, y resistente. Los ensayos de resistencia a antibiosis de los cultivares se condujeron en cámara de crecimiento y se evaluaron con algunos índices biológicos de

  18. Penicillium expansum versus antagonist yeasts and patulin degradation in vitro

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    Alexandre Rodrigo Coelho

    2007-07-01

    Full Text Available Taking into account the preliminary antagonistic/biodegradation property showed by Pichia membranifaciens and Sporobolomyces roseus, which decreased the initial patulin concentration of 588.4 to 290.0 µg/mL, ability of P. ohmeri 158 in biocontrol against Penicillium expansum and patulin decrease in vitro was performed. The culture supernatant of P. ohmeri 158 was effective against 66.17% micelial growth, indicating antibiosis related with the killer phenomenon. The initial patulin concentration of 223 µg in the presence of P. ohmeri 158 cells was decreased over 83% of the original concentration, when incubated at 25ºC/2 days and > 99% after 5 days incubation time, with undetectable patulin level after 15 days. The initial pH 4.0 decreased to pH 3.3 along 15 days experiment, suggesting that patulin decrease was an active process and a consequence of yeast metabolism. The results suggested that P. ohmeri 158 could be a promising alternative for the inhibition of P. expansum growth and patulin degradation.Considerando o antagonismo e degradação de patulina detectados em Pichia membranifaciens e Sporobolomyces roseus no estudo preliminar, este trabalho avaliou o efeito antagônico de Pichia ohmeri 158 no desenvolvimento de Penicillium expansum e a degradação de patulina "in vitro". O sobrenadante do cultivo de P. ohmeri 158 inibiu 66,17% do desenvolvimento micelial, indicando antibiose relacionada ao fator killer. A concentração inicial de patulina (223 µg na presença de células íntegras de P. ohmeri foi reduzida em mais de 83% após dois dias de incubação a 25ºC e superior a 99% após 5 dias, com níveis indetectáveis no 15º dia. O decréscimo do pH 4,0 inicial para pH 3,3 sugeriu que a eliminação de patulina é um processo ativo e uma conseqüência do metabolismo da levedura. Os resultados obtidos concluem que P. ohmeri 158 é uma alternativa promissora na inibição do desenvolvimento de P. expansum e na degradação de

  19. The formation of microorganism communities in the soil under the effect of chitosan and runner bean (Phaseolus coccineus L. cultivation

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    Danuta Pięta

    2013-12-01

    Full Text Available The subject of the studies was the soil with introduced solutions containing 0,1% chitosan. These materials were obtained from the Institute of Chemical Fibres in L6d2 (in the form of a microcrystalline gel and also from the Department of Food Biochemistry and Chemistry of the University of Agriculture in Lublin (in a liquid form,i.e.dissolved in acetic acid. In order to set an experiment in a growth chamber, grey brown podzolic soil formed from loesses and taken from a mechanically treated belt of black fallow was used. The soil (1000 g was watered every 8 days with 100 ml of examined chitosan solutions per pot. Control soil was watered with sterile distilled water. Seven days after each watering, soil samples were taken for microbiological analysis. Then 25 runner bean seeds were sown into each pot. After six weeks of plants' growth the experiment was finished and the number of plants was counted, their healthiness determined and soil microbiological analysis was performed. Regardless of chitosan form introduced to the soil it stimulated the growth of bacteria and fungi, since in these experimental combinations was found a significantly higher number of microorganisms as compared with the control. A particular high increase in the number of microorganism colonies was observed with simultaneous growth of plants and the application of chitosan. A considerable increase of fungi colonies from the Trichoderma genus was found in the soil treated with chitosan in the form ofboth a microcrystalline gel and a liquid. The species of this genus are considered to be antagonists; it affects pathogenic fungi through competition, antibiosis and over-parasitism. An increase in colonies of saprophytic microorganisms, including antagonistic ones of Bacillus spp. and Pseudomonas spp. was observed in the soil treated with chitosan . On the other hand, in the soil after the growth of bean and treated watered with chitosan only few colonies of Fusarium oxysporum f

  20. Study on Pharmacodynamics of Qixiang Oral Liquid in Anti-respiratory Tract Infection%“芪香”口服液抗呼吸道感染的主要药效学研究

    Institute of Scientific and Technical Information of China (English)

    吴贤波; 陈颖; 戴敏; 马萍

    2013-01-01

    Objective: The experiment intends to observe the pharmacodynamics of Qixiang Oral Liquid, a herbal compound preparation made from Huangqi ( Radix Astragali) , Xiangru ( Herba Moslae ) , and Bohe ( Herba Menthae ) , in anti-respiratory tract infection. Methods: The fever-relieving of Qixiang Oral Liquid with rabbits' temperature changes caused by pyogenicity was observed ;anti-inflammatory effect of was observed by the test of auricle swelling in mice; pain-relieving was by hot plate test in mice;bacteriostasis to common seen respiratory tract bacteria was observed by anti-bacteria test in vitro. Results:Qixiang Oral Liquid could relieve fever in fever rabbit model caused by endotoxin, inhibit auricle swelling caused by xylene, significantly increase pain threshold caused by hot plate test,and work to bacteriostasis for common seen bacteria in respiratory tract. Conclusion:Qix-iang Oral Liquid, an effective medicine in anti-respiratory tract infection, has actions to relieve fever, anti-inflammation, relieve pain and antibiosis.%目的:观察“芪香”口服液抗呼吸道感染主要药效学作用.方法:采用家兔致热反应后的体温变化,观察“芪香”口服液的解热作用;采用小鼠耳廓肿胀试验,观察“芪香”口服液的抗炎作用;采用小鼠热板试验,观察“芪香”口服液的镇痛作用;采用体外抑菌实验,观察“芪香”口服液对常见呼吸道细菌的抑菌作用.结果:“芪香”口服液对内毒素所致家兔发热模型具有退热作用,能抑制二甲苯所致小鼠耳廓炎性肿胀;可明显提高热板引起的小鼠痛阈值;对呼吸道常见的病原菌有一定的抑菌作用.结论:“芪香”口服液是抗呼吸道感染的有效药物,具有显著的解热、抗炎、镇痛、抗菌的作用.

  1. Progress on the Research of Marine Organisms Having Anti-tumor Activity%具有抗肿瘤活性的海洋生物研究进展

    Institute of Scientific and Technical Information of China (English)

    温卓; 郎朗

    2015-01-01

    海洋环境与陆地环境有着显著的差异,其具有高盐、高压、低温、寡氧的特点,自身含有生物活性物质的海洋生物在极端的环境下经过长年的生长和代谢,积累了大量的抗菌、抗病毒、抗肿瘤活性物质等,其抗肿瘤作用已经成为目前研究的热点之一。海洋抗肿瘤药物主要来源于海洋动物、植物和微生物,通过现代科学方法和技术,从海洋生物中寻找具有抗肿瘤活性的化合物开发出具有抗肿瘤作用的海洋药物具有广阔前景。从而积极研究并深入探讨海洋生物的抗肿瘤活性,对治疗人类重大疾病具有现实意义。%The environment of the ocean has many characteristics widely different from it of the land such as high salinity, high pressure, low temperature and oligotrophic conditions so that numerous varieties of biont produce a mass of bioactivators in the ex-treme environment of the ocean, for example, antibiosis, antiviral, antitumor activities and so on. This article introduced three sources of marine anticancer drugs from marine animals, plants and micro-organisms, provided a reference for looking for the compounds with antitumor activity from marine organisms and obtained effective marine anticancer drugs through modern scientific methods and tech-niques. Thereby it could contribute to the development of marine drugs for clinical treatment of human major diseases and the further development of marine biological research.

  2. Identification of Volatile Metabolites from Fungal Endophytes with Biocontrol Potential towards Fusarium oxysporum F. sp. cubense Race 4

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    A. S. Y. Ting

    2010-01-01

    Full Text Available Problem statement: Fungal endophytes are widely studied for their potential as biocontrol agents towards fungal pathogens. In vitro assessments usually reveal their antibiosis and mycoparasitism nature, but little is understood regarding their production of volatile metabolites as mechanisms of antagonism. Approach: This study explored the potential of fungal endophytes in controlling the pathogen responsible for Fusarium wilt disease. Nine fungal endophytes were tested for their ability to inhibit the growth of the pathogenic Fusarium oxysporum F. sp. cubense race 4 (FocR4 via production of volatile inhibitory metabolites. The type of volatile metabolites produced were subsequently characterized and identified using the Gas-Chromatography Mass-Spectrophotometry (GCMS. Results: Eight of the isolates (BTF05, BTF07, BTF08, BTF15, BTF21, WAA03, WAA02, MIF01 showed positive results with percentages of inhibition varying from 1.43-31.43% while one isolate (ALF01, showed negative result (0% inhibition. Volatile profiles showed that these fungal endophytes produced between 15-47 volatile metabolites per isolate. However, the more volatile metabolites produced by a single endophyte does not indicate better biocontrol potential. Isolate BTF05 produced 47 different volatile metabolites, but has only 8.57% inhibition, compared to isolate BTF21 with 15 metabolites but a percentage of 11.43% inhibition. The potency of the volatile metabolites produced may also influenced the biocontrol potential of the fungal endophytes as some isolates such as BTF08 and MIF01 have only two to three known inhibitory metabolites but have higher PIDG values at 31.43 and 11.43%, respectively. Contrary, isolates WAA02 and WAA03 which has five to six metabolites but PIDG values of less than 3%. Conclusion: Fungal endophytes have the ability to produce several types of volatile metabolites to inhibit the growth of FocR4. These volatile inhibitory metabolites can be further

  3. Effect of salt stressed wheat varieties on life history of tribolium castaneum (hebrst) (tenebrionidae: coleoptera)

    International Nuclear Information System (INIS)

    In the present investigation an attempt was made to determine the antibiosis of three salt stressed wheat varieties (Shafaq, Inqlab-91 and Sehar-2006) at three salinity levels (8, 12 and 16 dS m/sup -1/) to red flour beetle, Tribolium castaneum (Herbst). The grains of three varieties were ground and sieved through 80 mesh. Life history parameters, i.e., larval and pupal durations and survivals, adult emergence, fecundity and egg hatching was observed by introducing 10 pairs of pupae, from previously reared beetles, on three varieties at their respective salt levels. One control was included with grains of the plants, which were irrigated with distilled water only. Results have shown that varieties had significant difference among the treatments for larval duration, which was significantly extended in different varieties at various salt levels. Mean longest larval duration (31.67 days) was recorded in Shafaq as respectively 8 (33.00 days), 12 (33.33 days) and 16 (30.33 days) dS m/sup -1/ salt level as compared to its control (31.00 days). Fecundity and egg hatching of T. castaneum differed among the wheat varieties irrespective of salt levels. In another experiment, response of SARC-1, SARC-2, SARC-3, SARC-4, SARC-5, SARC-6, SARC-7, SARC-8, LU-26S, to life history parameters of T. castaneum showed that significant difference in the number of eggs, hatching percentage, larval and pupal survival was found. The number of eggs was significantly lower in variety SARC 1 (126.00) followed by SARC 2 (128.75), SARC 3 (132.25) while was significantly higher in SARC 5 (151.75). Egg hatching percentage was lower in SARC 6 (39.38%) and significantly higher in SARC 5 (58.42%). Larval survival was significantly less in SARC 7 (36.99%) and more in SAR (52.25%). Pupal survival was significantly lower in SARC 1 (20.54%) while higher in SARC 8 (42.11%). Based on results it may be stated that salt stressed wheat varieties have significant impact of the biology of T. castaneum. (author)

  4. BIOLOGICAL CONTROL OF DAMPING-OFF FUNGI OF AGOHO (CASUARINA EQUISETIFOLIA L. USING ANTAGONISTIC BACTERIA

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    F.A. DELA PEÑA

    1994-01-01

    essential requirement of microorganisms can serve as potentially possible basis for competition. Another was antibiosis which is an inhibitory effect exerted by an organism upon another organism through the production of antibiotic compounds. Moreover, several strains of bacteria are effective in lysing cell walls of pathogenic fungi under laboratory conditions. Lysis is often attributed to production of cell wall degrading enzymes like chitinase and gluconase that may hydrolyze major constituents of fungal cell walls.

  5. Towards understanding the ecology and mechanisms of biocontrol of Clonostachys rosea IK726

    Institute of Scientific and Technical Information of China (English)

    Mette Lübeck; Inge M B Knudsen; Birgit Jensen; Mojtaba Mamarabadi; Dan Funck Jensen

    2004-01-01

    @@ Clonostachys rosea (syn. Gliocladium roseum ) IK726 was originally selected as an effective biocontrol agent (BCA) against cereal seed borne diseases caused by Fusarium culmorum and Bipolaris sorokiniana. We have studied the efficacy of the antagonist against different pathogens in several crops and found that the antagonist also is able to control Alternaria radicina and A. dauci on carrot seeds and different cold-storage fungi in acorns. IK726 is also able to reduce severity of soil borne Pythium spp. in cabbage, carrot and sugar beet. In addition, growth-promoting effects of IK726 have been demonstrated in barley and tomato. In order to develop and improve application methods and control strategies, essential basic studies of ecology and the mechanisms of control of IK726 is needed and has led us to use various molecular tools. The UP-PCR technology is used for strain recognition and we have developed GUS and GFP-transformants that resembles the wildtype strain in ecological fitness parameters. Using either the GUS-transformant or UP-PCR we have found that IK726, when applied with seeds, reproduces and survives several months in the rhizosphere of field grown barley and carrot.The GFP-transformant is used to study the behavior and in situ interactions of the antagonist with pathogens and plants. Using the GFP marker, we have observed conidial germination, colonization and conidiogenesis in natural soil, in vermiculite and on carrot and barley seed and roots and on barley leaves. Moreover in situ interactions with Alternaria on carrot material have been studied. The modes of action of C. rosea are not well understood but enzymatic activity, mycoparasitism, substrate competition, antibiosis and induced resistance are thought to play a role. Barley treated with C. rosea IK726 has an enhanced chitinolytic and glucanolytic activity compared to the activity in non-treated barley in pot experiments with field soil. Identification of chitinases from IK726 and studies

  6. Antagonism of Beauveria bassiana against Two Fusarium spp.Pathogenic to Cotton%球孢白僵菌对两种植物病原镰孢的拮抗作用

    Institute of Scientific and Technical Information of China (English)

    张胜利; 李增智

    2011-01-01

    体外测定了球孢白僵菌Beauveria bassiana对两种棉花病原镰孢——棉花枯萎病菌Fusarium oxysporium f.sp.vasinfecturn和棉花红腐病菌Fusarium verticillioides的拮抗作用。平板对峙培养时,两种镰孢的生长均受到明显抑制。不同含孢量的球孢白僵菌对两种镰孢的抑制效果不同,且抑制率与孢子浓度成显著的线性量效关系;在接种量为6×107孢子.mL-1时,对两种菌的抑制率均达到90%以上,对红腐病菌的抑制率稍高。白僵菌代谢液对两种植物病原菌也表现出抑菌作%In vitro antagonism of Beauveria bassiana,an entomopathogenic fungus,was tested against Fusarium oxysporium f.sp.vasinfecturn,pathogen of cotton wilt,and F.verticillioides,pathogen of cotton red rot.On dual culture,B.bassiana showed obvious inhibition on the growth of the two pathogens.Different doses of conidia had different inhibitory effects,with inhibition rate linearly correlated to inoculum,suggesting that the antagonism was associated with competition for nutrition and space.The inhibition on the two pathogens was both over 90% at inoculum of 6×107 spores·mL-1,slightly higher on F.verticillioide.The metabolite in SDY shake culture of B.bassiana also displayed inhibition,with inhibition rate linearly correlated to metabolite concentration,suggesting that the antagonism was also associated with antibiotic substances.Based on the comparison of inhibition rates,antibiosis was considered to contribute more than competition.In the analysis on the antibiotic metabolite,none of the lyophilized supernatant extracted by 4 different organic extractants showed obvious inhibition on the Fusarium spp.,while addition of crude extract of either polysaccharide or protein significantly inhibited mycelium growth of the two Fusarium spp.,suggesting that the main inhibitory substances are polysaccharide and protein with high molecular weight.

  7. Bacteriocins: molecules of fundamental impact on the microbial ecology and potential food biopreservatives

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    Evandro Leite de Souza

    2005-07-01

    Full Text Available Bacteriocins are proteic molecules synthesized for various lineages of Gram-positive and Gram-negative bacteria when exposed to stressful conditions. Bacteriocins have been characterized as molecules of high antimicrobial property even at low concentrations, provoking the microbial survival inhibition by antibiosis. These substances have their synthesis mediated for genetic mechanisms and develop their lethal action on the microbial cell by multiples mechanisms that can act of isolated or concomitant way culminating with microbial cell killing. This molecules class presents characteristic of stability to heat, low pH, refrigeration and freezing, and resistance to weak organics solvents, salts and enzymes. On the other hand, they are very sensitive to proteolytic enzymes action. Bacteriocins could appear as potential agents to be applied in food conservation systems in order to provide microbiologically stable foods.Bacteriocinas são moléculas protéicas sintetizadas por várias linhagens de bactérias Gram-positivas e Gram-negativas quando submetidas a condições de stress. São ainda caracterizadas como moléculas de alto poder antimicrobiano mesmo em baixas concentrações, provocando a inibição da sobrevivência microbiana através de uma ação de antibiose. As bacteriocinas têm seu processo de síntese mediado por mecanismos genéticos, e desenvolvem sua ação letal sobre a célula microbiana por intermédio de múltiplos mecanismos que podem agir de forma isolada ou concomitante culminando com a morte da célula microbiana. Estas moléculas apresentam características de estabilidade ao calor, baixo pH, refrigeração, congelamento, resistência a ácidos orgânicos fracos, sais e enzimas, porém são muito sensíveis à enzimas proteolíticas. Assim, as bacteriocinas podem aparecer como potenciais agentes para serem aplicados em sistemas de conservação de alimentos com objetivo de prover alimentos microbiologicamente estáveis.

  8. Resistência de genótipos de feijoeiro a Bemisia tabaci biótipo B Resistance of bean genotypes to Bemisia tabaci biotype B

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    Lucas Castro Torres

    2012-01-01

    Full Text Available O estudo de genótipos de feijoeiro resistentes à mosca-branca Bemisia tabaci (Genn. biótipo B (Hemiptera: Aleyrodidae é de grande importância devido aos danos ocasionados por essa praga à cultura. Neste trabalho, foram estudados a atratividade para adultos, a preferência para oviposição em testes com e sem chance de escolha, o ciclo ovo-adulto e o tipo e número de tricomas presentes nos folíolos. Os experimentos foram realizados em casa de vegetação avaliando-se, inicialmente, cem genótipos de feijoeiro. A resistência do tipo não-preferência para alimentação e/ou antibiose foi observada nos genótipos ARC-3, IAC-Alvorada e Canário 101, sendo a emergência de adultos fortemente influenciada pelos genótipos. Também se observou correlação negativa moderada entre o número de ovos e o número de tricomas glandulares, e correlação positiva muito forte entre o número de ovos e o número de tricomas tectores unciformes.The study of bean genotypes resistant to the whitefly Bemisia tabaci (Genn. B biotype (Hemiptera: Aleyrodidae has been of great importance due to the damage caused by this pest. In this research, bean genotypes were evaluated regarding attractiveness to whitefly adults, the preference for oviposition in free-choice and non choice tests, egg-to-adult development time and characterized for the presence, type and number of trichomes. The experiments were carried out under greenhouse conditions initially evaluating 100 bean genotypes. The non-preference type of resistance for feeding and/or antibiosis was observed in the genotypes ARC-3, IAC-Alvorada and Canário 101, and the emergence of adults was strongly influenced by the genotypes. It was also observed a moderate negative correlation between the number of eggs and the number of glandular trichomes, as well as a very strong positive correlation between the number of eggs and the number of unciform non-glandular trichomes.

  9. Evaluation of potential antagonistism in yeasts, seeking biocontrol of spoilage by Penicillium expansumAvaliação do potencial antagônico de leveduras, visando biocontrole de deterioração por Penicillium expansum

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    Kei-ichi Harada

    2011-12-01

    Full Text Available Considerable losses during apple fruit storage occur due to microbiological diseases, mainly caused by Penicillium expansum, which in addition to fruit pulp deterioration produces patulin, a mycotoxin with carcinogenic and teratogenic activity. Biological control of post-harvest disease by antagonist yeasts focused on killer toxins is an appreciable alternative to the chemical fungicides, due to the low possibility of toxic residues demonstrated during fermentative processes. Twenty out of 44 yeasts (16 isolated from fruits, 10 from corn silage and 18 from laboratory anthill, showed antagonism against spores of P. expansum. The assay in solid medium pointed the strongest nutrient competition antagonism by D. hansenii strain C1 (31 mm inhibition diameter, while D. hansenii strain C7 (15 mm showed higher antibiosis and parasitism pattern. In the following step the extracellular activity was tested performing the assay with culture supernatant in Yeast Medium agar, where C. guilliermondii P3 was more effective against conidia germination (inhibition rate of 58.15% while P. ohmeri showed better inhibition on micelial growth (66.17%. The antibiosis showed by both yeasts could suggest probable mechanism associated with killer phenomenon, once both strains were killer positive against sensitive reference strains (S. cerevisiae NCYC 1006 and P. kluyveri CAY-15. In order to enhance the production of antifungal substance, these yeasts were cultivated with P. expansum, but the difference between culture supernatant obtained from yeasts cultivated alone and with mould was not significant (P > 0.05. The results demonstrated that the yeasts application constitute a promising tool, enhancing the biological control of P. expansum in post-harvest diseases of apple fruit.As perdas consideráveis no armazenamento de maçãs decorrem principalmente de desordens microbiológicas, causadas por Penicillium expansum, que além de colonizar o fruto e causar dano

  10. Characterisation and identification of Trichoderma isolates from a South Australian soil suppressive to Rhizoctonia solani on wheat%南澳大利亚麦田茄丝核菌抑病土中木霉菌的特性和鉴定

    Institute of Scientific and Technical Information of China (English)

    杨合同; Maarten H RYDER; 唐文华

    2005-01-01

    从抑制Rhizoctonia solani的麦田土中分离到木霉菌,依据形态特征,鉴定为 Trichoderma pseudokoningii, T. parceramosum, T. longibrachiatum 和T. harzianum.取样土壤为灰质砂壤土, pH 8.4 (H2O),位于南澳大利亚的埃文.研究了与生物防治作用机制相关的生理学特性包括几丁质酶活性、β-1,3-葡聚糖酶活性、内切葡聚糖酶活性、抗菌活性以及重复寄生能力.T. pseudokoningii生长速度快但是产分生孢子少,但是T. parceramosum产分生孢子多.与其他种类相比,Trichoderma pseudokoningii的分离频率高,在盆载条件下对小麦Rhizoctonia solani根腐病以及全蚀病防治效果高,对R. solani的重复寄生能力强.Trichoderma pseudokoningii菌株间的重复寄生能力差异不明显,但在几丁质酶活性和β-1,3-葡聚糖酶活性上有明显差别.依据平板抑菌能力,可将木霉菌株分为3个组.菌株在不同pH培养基上的生长速度不同,但没有发现特别能适应碱性条件而快速生长的菌株,虽然这些菌株都分离自碱性土壤.%Trichoderma pseudokoningii, T. parceramosum, T. longibrachiatum and T. harzianum were identified based on morphological characterisation of isolates from a Rhizoctonia solani suppressive wheat field soil. The soil, a calcareous sandy loam, pH 8.4 (H2O) was collected from Avon, South Australia. Physiological characters which are possibly connected to biocontrol mechanisms including chitinase,β-1,3-glucanase and endoglucanase activity, antibiosis and mycoparasitism were investigated.T. pseudokoningii was fast growing and poor in conidiation, but T. parceramosum isolates were good conidium producers.Compared to the other species,Trichoderma pseudokoningii showed much higher isolation frequency, was better in controlling Rhizoctonia solani root rot and take-all of wheat in a pot experiment, and had stronger mycoparasitic ability toward R. solani. No remarkable difference was found among Trichoderma pseudokoningii

  11. Commercial development of Trichoderma species for control of soil-borne vegetable diseases and their integration into standard crop management practices

    Institute of Scientific and Technical Information of China (English)

    Kirstin L McLean; John S Hunt; Alison Stewart

    2004-01-01

    @@ A 10 year research programme at Lincoln University, investigating the use of Trichoderma species for biological control of soil-borne diseases of vegetable crops, has resulted in the development of two commercial products. TrichodryTM 6S and TrichoflowTM 6S based upon Trichoderma hamatum isolate 6SR4, are used to control Sclerotinia lettuce drop disease. The Trichodry 6S product is formulated as a dry flake, which is incorporated into nursery seedling mix and the Trichoflow 6S is a wettable powder which is used as a top-up drench before planting. The treatment stimulates seedling establishment and vigour and protects the developing seedling from Sclerotinia minor infection after transplanting in the field. The second commercial product is TrichopelTM Ali 52. Based upon Trichoderma atroviride isolate C52, which is used to control Sclerotium cepivorum, the causal agent of Allium white rot disease. The product is formulated as a granule and applied into the furrow at planting time. The fungus proliferates in the rhizosphere region and protects the growing seedling from pathogen attack by a combination of nutrient competition, antibiosis and mycoparasitism. The use of Trichopel Ali 52 under low to medium disease pressure in Pukekohe, the main vegetable growing region of New Zealand, gave a three fold cost benefit through yield increases in the 2003-2004 season. Current field development work involves the use of a wettable powder formulation of T. Atroviride distributed via a T-tape irrigation system to target mid-season applications of the product to the onion roots. Both products perform well under low to moderate disease pressure but, when there is high disease pressure, an integrated programme is required to give satisfactory control. Current research is focused on gaining a greater understanding of the biotic and abiotic factors, which influence biocontrol activity under field conditions as a means to enhance integrated control approaches. For example, T

  12. Selection of endophytic fungi from comfrey (Symphytum officinale L. for in vitro biological control of the phytopathogen Sclerotinia sclerotiorum (Lib. Seleção de fungos endofíticos de confrei (Symphytum officinale L., buscando controle biológico in vitro do fitopatógeno Sclerotinia sclerotiorum (Lib.

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    Rafaeli Rocha

    2009-03-01

    Full Text Available Biological control consists of using one organism to attack another that may cause economic damage to crops. Integrated Pest Management (IPM is a very common strategy. The white mold produced by Sclerotiniasclerotiorum (Lib. causes considerable damage to bean crops. This fungus is a soil inhabitant, the symptoms of which are characterized by water-soaked lesions covered by a white cottony fungal growth on the soil surface and/or the host plant. Possible biological control agents taken from plants are being investigated as phytopathogen inhibitors. These are endophytic microorganisms that inhabit the intercellular spaces of vegetal tissues and are often responsible for antimicrobial production. The objective of the present study was to select endophytic fungi isolated from comfrey (Symphytumofficinale L. leaves with in vitro antagonist potential against the phytopathogenic fungus S. sclerotiorum. Twelve isolates of endophytic fungi and a pathogenic strain of S. sclerotiorum were used in the challenge method. With the aid of this method, four endophytes with the best antagonistic activity against S. sclerotiorum were selected. Pathogen growth inhibition zones were considered indicative of antibiosis. The percentages of pathogenic mycelia growth were measured both with and without the antagonist, resulting in growth reductions of 46.7% to 50.0% for S. sclerotiorum. These analyses were performed by evaluating the endophytic/pathogenic mycelia growth in mm/day over an eight-day period of antagonistic tests.O controle biológico consiste no uso de organismos que atacam outros que causam danos a culturas de plantas. Esta é uma estratégia muito utilizada no Controle Integrado de Pragas (CIP. O mofo branco, causado por Sclerotiniasclerotiorum (Lib., causa danos em culturas de feijão. Este fungo é encontrado no solo e seus sintomas são caracterizados por lesões úmidas cobertas por micélios algodonosos, crescidos a partir do solo e/ou da planta

  13. Resistência de genótipos de feijão-caupi ao Callosobruchus maculatus (Fabr. (Coleoptera: Bruchidae. = Resistance of cowpea genotypes to Callosobruchus maculatus (Fabr. (Coleoptera: Bruchidae.

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    Roberson Oliveira Carvalho

    2011-04-01

    replications were used, each one had 100g of seeds of each genotype which were infested with 20 adult insects randomized collected in seven days during the laboratory creation. After the days of feedlot the insects were removed and 10 g of seed subsampled from the 100 g previuosly infested. The variables evaluated were: the number of viable and, unviable eggs, immature phase duration (days, number of emerged insects, emerged insect percentage, dry matter consumed and the dry matter consumed/insects. Results revealed that: BRS-Patativa was the less preferred foroviposition by C. maculatus, presenting, therefore, non-preference type resistance to oviposition to the species referred; BRSPatativaand BRS-Paraguassú, are carrier of the antibiosis type resistance, as they have provided an increase in the larval phase of C. maculatus. Furthermore, none of the tested genotypes in this experiment presented the non-preference type resistance of feeding to C. maculatus.

  14. Resistance of squash cultivars to Aphis gossypii Resistência de cultivares de abobrinha italiana a Aphis gossypii

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    Edson LL Baldin

    2009-09-01

    Full Text Available The Cucurbitaceae plants are damaged by attack of a wide spectrum of insects and microorganisms. Among the sucker insects causing damages on squash Cucurbita pepo (L., the aphid Aphis gossypii (Glover (Hemiptera: Aphididae is pointed as one of the most important, once their nymphs and adults suck the sap of the leaves continuously, besides being potential vector of virus. The present research evaluated different cultivars, aiming to identify the resistance against this aphid. The cultivars Novita, Sandy, Caserta Cac Melhorada, Novita Plus, Samira, AF-2858 and Caserta TS were used in laboratory assays (T= 25±2ºC; RH= 70±10% and fotophase= 12 h. In the immature phase the duration of nymphal instars was evaluated, the total duration and their viability, confining individuals on leaf disks from cultivars. In the adult phase the duration of reproductive period, the fecundity and the biological cycle were observed. The cultivar 'Sandy' expressed high level of antibiosis and feeding non-preference against A. gossypii, increasing the nymphal stage and causing mortality near to 70%. Besides, this cultivar reduced the production of nymphs and the longevity of the insects. The 'Novita Plus' cultivar also induced significant nymphal mortality, however in lower levels than those verified in 'Sandy', indicating a moderate resistance.As plantas da família Cucurbitaceae são prejudicadas pelo ataque de um amplo espectro de insetos e microrganismos. Dentre os insetos sugadores que atacam a abobrinha Cucurbita pepo (L., o pulgão Aphis gossypii (Glover (Hemiptera: Aphididae merece destaque, uma vez que suas ninfas e adultos sugam a seiva das folhas constantemente, além de ser potencial vetor de vírus. A presente pesquisa foi realizada com o objetivo de avaliar diferetes cultivares de abobrinha italiana quanto à resistência a esse pulgão. Utilizaram-se as cultivares Novita, Sandy, Caserta Cac Melhorada, Novita Plus, Samira, AF-2858 e Caserta TS em ensaios

  15. Relationship between Resistance of Rice Varieties to Rice Gall Midge (Orseolia oryzae) Biotype China Ⅳ and Total Phenol Contents%水稻品种对稻瘿蚊中国Ⅳ型的抗性及其与总酚含量关系

    Institute of Scientific and Technical Information of China (English)

    农春莲; 吴碧球; 黄所生; 黄凤宽

    2011-01-01

    To clarify resistance and the mechanism of rice varieties to rice gall midge (CM) biotype China IV, antibiosis of 11 rice varieties to CM biotype China IV were tested, and the correlation between total phenol content and the resistance of rice varieties to CM was studied. The results indicated that ARC5984, 570011, ARCS833, RP1976-18-64-2 and RNR3070 were highly resistant to GM biotype China IV, and there were no preference in opposition and incursion of CM biotype China IV to resistant and susceptible rice varieties. A majority of larvae died, and the survival ones developed very slowly, most of them stayed in first instar larvae in high resistance rice varieties. The total phenol contents in high resistance variety 570011 (2.63 mg/g) were the highest, and the total phenol contents in susceptible variety W1263 (1.23 mg/g) were the lowest. The total phenol contents in resistant varieties 570011, ARC5984, ARC5833, RP1976-18-6-4-2, RNR3070 and Duokangl were significantly higher than the susceptible varieties TNI, W1263. There were obvious positive correlations between the total phenol contents in rice varieties leaves and the resistance of rice varieties to CM biotype China IV.%为明确水稻品种对稻瘿蚊中国Ⅳ型的抗性及其机制,研究了11个水稻品种对稻瘿蚊中国Ⅳ型的抗生性,并探讨总酚含量与水稻品种抗稻瘿蚊中国Ⅳ型的关系.结果表明,ARC5984、570011、ARC5833、RP1976 -18-6 -4-2、RNR3070高抗稻瘿蚊中国Ⅳ型;稻瘿蚊中国Ⅳ型对抗感水稻品种无产卵和入侵偏嗜性;在高抗水稻品种稻株内大部分幼虫死亡,存活幼虫发育缓慢,多数停留在一龄虫态阶段.高抗品种570011的总酚含量最高,达2.63 mg/g,感虫品种W1263的总酚含量最低,仅有1.23 mg/g;抗虫品种570011、ARC5984、ARC5833、RP1976-18-6-4-2、RNR3070和Duokangl的总酚含量极显著高于感虫品种TN1和W1263.水稻品种对稻瘿蚊中国Ⅳ型的抗性与稻叶总酚含量呈显著正相关.

  16. Review on the Research of the Components, Pharmacological Actions and Toxicity of Polygonum Multiflorum Thunb(Heshouwu)%何首乌成分、药理及毒副作用相关的研究进展

    Institute of Scientific and Technical Information of China (English)

    楼招欢; 吕圭源; 俞静静

    2014-01-01

    [Objective] To sum up researches on components, pharmacological actions and toxicity of Polygonum multiflorum Thunb(Heshouwu). [Method] The research reference about Heshouwu in CNKI, VIP and PUBMAD database is col ected and calssified to three aspects on components, pharmacological actions and toxicity.[Result]①On components:Heshouwu contains stilbene, lecithin, anthraquinone, flavonoids, tannin and trace elements. The stilbene and anthraquinone are the mainly active components. Producing area, growth years, harvest time and processing methods are factors affecting the content of the components such as TSG in Heshouwu; Macroporous adsorption resin is the main separation method for preconcentration of TSG and anthraquinone constituents; ② On pharmacological actions and toxicity: Heshouwu has effects of hypolipidemic and liver protection, antioxidative, anti-osteoporosi, hpyerglycemic, antidepressive and antibiosis, the hypolipidemic and liver protection are the main effects which have been studied more. A reversible liver injury which displays as abnormal liver function parameter and bile metabolic disorder would be induced if the Heshouwu is administrated with a large dosage for long term. The possible components which would induce the toxicity in Heshouwu are tannin and anthraquinone, and the anthraquinone is the component with double effects of toxicity and therapy which should be considered in clinical application. [Conclusion]Reducing lipid and protecting liver is the main pharmaceutical function of the herb. As a commonly used Chinese herb for liver protection, the studies on alcoholic hepatic injury protection of Heshouwu may be a point for the researchers to focus on. The comparison studies on hypolipidemic and liver protection between Hesouwu and its processing products, and the correlations between components and pharmacological actions are worth study further.%[目的]总结何首乌在成分、药理和毒副作用方面的研究情况。[方法]查

  17. 药性温的现代研究及相互关系%Modern Research and Relationship of Warm Chinese Medicine Properties

    Institute of Scientific and Technical Information of China (English)

    李瑞奇; 苗明三

    2012-01-01

    Objective: To explore relationship between warm Chinese medicine properties and functions, pharmacological action, Chinese medical indications,modern medical indications,medicine flavour, channel tropism and chemical composition. Methods: Use the "features-pharmacology-clinical of Chinese medicine database systems" .inquiry associated frequency between "warm" and functions,pharmacology , Chinese medical indications, modem medical indications, flavour of a medicine, channel tropism, chemical composition, according to the frequency,take cover 2/3 of most high frequency for basic area,take cover 2/3 of remaining most high frequency for joint area, remaining for extended area. Results: Basic functions of warm Chinese medicine are relieving pain, invigorating the circulation of blood,dispelling the wind,promoting Qi,tonifying the kidney,dispelling cold;basic pharmacological actions are anti-inflammatory,antibiosis , analgesia, affecting cardiovascular system, antitumor, tranquilizing, eliminating phlegm, affecting immune function, relieving asthma ;TCM basic indications are pain in rheumatism arthralgia,emesis,fell-bashing injuries,eating less,much sputum,bedwetting,impotence wet dream, abdominal pain due to parasitic infestation, epigastric abdominal pain in the cold, phlegm, edema, cough, frequent micturition, dysmenorrheal; Modern medicine basic indications are coronary heart disease,chronic bronchitis,impotentia,injuries from falls, bronchial asthma, shingles, toothache, malaria, gastric ulcer, vomiting, stomach pain, scabies, cough, angina, disease dysentery, whooping cough, hepatitis; basic flavour of a medicine Combined with warm Chinese medicine are hot, sweet, bitter; Basic channel tropisms are liver, spleen, kidney, stomach, lung; The basic chemical compositions of warm Chinese medicine are essential oils, esters, organic acids, sugar,inorganic, alkaloids, flavonoid, amino acid, glycoside, protein. Conclusion; Define relationship between warm Chinese medicine

  18. Phenolic components from Petasites tricholobus%毛裂蜂斗菜中酚类成分研究

    Institute of Scientific and Technical Information of China (English)

    张勇; 郭夫江; 曾鹏; 贾琦; 李医明; 朱维良; 陈凯先

    2012-01-01

    -ringin (3), tangshenosides II (4), 4-hydroxy-2, 6-dimethoxyphenol-l-O-β-D-glueopyranoside (5), 4-hydroxymethyl-2, 6-dimethoxy-phenyl-1-O-β-D-glucopyranoside (6), arbutin (7), rutin (8), kaempferol-3-O-α-L-rhamnopyranosyl-( 1→6)-β-D-glucopyranoside (9), quercetin-3-O-β-D-glucopyranoside (10), kaempferol-3-O-β-D-glucopyranoside (11), afzelin (12), petasiphenol (13), caffe-ic acid (14), chlorogenic acid (15), 2-hydroxy-5-acetylbenzoic acid (16), p-hydroxy-benzoic acid (17), protocatechuic aldehyde (18) , and p-hydroxy-phenylpropionic acid (19). Conclusion: Above result shows that phenolic compounds contained in P. tricholobus mainly include simple phenols, phenolic glycosides. coffee acid and flavonoid glycosides. Among them, compound 1 was separated from the composite family for the first time: compounds 2-7, 9, 11, 12, 16, 19 were separated from the genus Petasites for the first time, and the others were separated from the plant for the first time. These compounds have been proved to have pharmacological effects such as anti-inflammation, antibiosis, antioxidantion.

  19. 不同生物制剂对猪致病性大肠菌的体外抑菌试验%Study on Antibacterial Effects of Different Biological Agents on Pig Pathogenic Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    王永芬; 席磊; 赵志军; 乔宏兴

    2012-01-01

    In order to provide the basis of using biological agents for preventing pig colibacillosis, the antibacterial effect of antibacterial drugs, Chinese medicine and probiotics had been inspected on intensive pig farms in Henan province. Antimicrobial susceptibility testing was performed on 87 pathogenic Escherichia coli isolates by using 15 antibacterial drugs, 14 Chinese medicines and 7 Lactobacil-lus and Bacillus. The results showed; (1) Pig pathogenic E. Coli showed multi resistance to 15 antimicrobials, and were resistances to 3 ~ 13 antimicrobial drugs. There were 31 different drug-resistance patterns and resistances percentage to 8 antimicrobials agents accounted for the highest ( 27. 59% ). A-mong the 15 antimicrobial drugs, resistant rate of norfloxacin and tetracycline arrived at 95. 4% , but high sensitive rates of polymyxin B, ceftiofur and amikacin were 92. 0% , 86. 2% and 74. 7% , respectively. (2) Besides sweet wormwood, 13 kinds of Chinese medicine had antibacterial effects on E. Co-li, among them, granatum (89. 7% ), skullcap (82. 7% ) and coptis (80. 5% ) had the optimal antibacterial effects. But the inhibition rate of houttuynia (19. 5% ), isatis root (12. 6% ) and androgra-phis (9. 2% ) was very low, less than 20%. (3) A better inhibitory capacity on pathogenic pig E. Coli is indicated by every probiotics. Except that Bacillus megaterium (88. 5% ), the others inhibition rate is above 90%. And the inhibition rate of lactobacillus - 2 and bacillus subtilis accounted for the highest 94. 3% and 92. 0% , respectively. This study shows that the resistance of pig pathogenic E. Coli is serious in intensive pig farm of Henan. It may instruct application of the antibiotics reasonably of the screening antibiosis drugs. The screening Chinese medicine and probiotics have better inhibitory capacity on pig pathogenic E. Coli, can provide significant basis for development of biological agent to control pig colibacillosis.%考察抗菌药物、中药、益生菌