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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. Antibiosis resistance in national uniform wheat yield trials against rhopalosiphum padi (L.)

    International Nuclear Information System (INIS)

    The germplasm of National Uniform Wheat Yield Trials (Normal) (2003-04) were screened against Rhopalosiphum padi L., bird cherry oat aphid at National Agricultural Research Centre, Islamabad. Twenty National Uniform Wheat Yield Trials (NUWYT) , Normal and 12 (NUWYT) rain fed varieties/ lines were evaluated for seedling bulk test to know the resistant, moderately resistant and susceptible wheat varieties/ lines. These results revealed that varieties Diamond and Margalla-99 and lines V-99022, 99B2278 and 7-03 were partially resistant, two lines V-00125 and SD-66 were susceptible and three varieties and ten lines were moderately resistant in seedling bulk test. For antibiosis studies, 10 varieties/ lines out of 20 were selected to know the effect of host plants on the fecundity of R. padi. Two varieties Wafaq-2007 and Diamond were the least preferred for fecundity and one line VOO125 was highly preferred for fecundity. (author)

  7. Wheat Antixenosis, Antibiosis, and Tolerance to Infestation by Delphacodes kuscheli (Hemiptera: Delphacidae), a Vector of "Mal de Rio Cuarto" in Argentina

    Czech Academy of Sciences Publication Activity Database

    Brentassi, M.E.; Corrales, C.; Snape, J.W.; Dixon, Anthony F. G.; Castro, A.M.

    2009-01-01

    Roč. 102, - (2009), s. 1801-1807. ISSN 0022-0493 Institutional research plan: CEZ:AV0Z60870520 Keywords : Delphaeodes kuscheli * wheat * antibiosis * antixenosis * tolerance Subject RIV: EG - Zoology Impact factor: 1.296, year: 2009

  8. Combining abilities for maize stem antibiosis, yield loss and yield under infestation and no infestation with pink stem borer

    OpenAIRE

    Butrón Gómez, Ana María; Malvar Pintos, Rosa Ana; Velasco Pazos, Pablo; Vales, M I; Ordás Pérez, Amando

    1999-01-01

    The pink stem borer (Sesamia nonagrioides Lef.) is the main pest of maize (Zea mays L.) in northwestern Spain. Little is known about combining ability for antibiosis and tolerance to this pest. Therefore, the objectives of this work were to estimate general combining ability (GCA), specific combining ability (SCA), and reciprocal effects for stem damage traits, yield, and yield loss by a complete diallel of 10 inbreds and to determine the most useful trait for evaluating the level of defense ...

  9. 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

  10. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. 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...

  15. 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

  16. 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。

  17. 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

  18. 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...

  19. 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...

  20. 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.

  1. Antibiosis and acidification by Panoea agglomerans strain E325 may contribute to suppression of Erwinia amylovora

    Science.gov (United States)

    Pantoea agglomerans strain E325, a commercially-available antagonist for fire blight of apple and pear, was originally selected through broad screening based on suppression of Erwinia amylovora on flower stigmas, but specific mechanisms were unknown. Bacterial modification of pH was evaluated as a p...

  2. 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.

  3. 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.

  4. Discovery of three woolly apple aphid Eriosoma lanigerum (Hemiptera: Aphididae) biotypes in Australia: the role of antixenosis and antibiosis in apple tree resistance

    Czech Academy of Sciences Publication Activity Database

    Costa, Arnaud; Williams, D. G.; Powell, K. S.

    2014-01-01

    Roč. 53, č. 3 (2014), s. 280-287. ISSN 2052-1758 Institutional support: RVO:60077344 Keywords : aphid * apple * biotype Subject RIV: EH - Ecology, Behaviour http://onlinelibrary.wiley.com/doi/10.1111/aen.12074/pdf

  5. 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...

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. QTL Information Table: 444 [Q-TARO

    Lifescience Database Archive (English)

    Full Text Available Resistance or Tolerance Insect resistance Green ... rice hopper RFLP C)Interval RIL Asominori IR24 B ... Yoshimura, A. (1999). QTL mapping of antibiosis to green ... leafhopper, Nephotettix virescens Distant and gree ...

  11. QTL Information Table: 172 [Q-TARO

    Lifescience Database Archive (English)

    Full Text Available qGRH-2 Resistance or Tolerance Insect resistance resistance to green ... rice leafhopper (GRH) RFLP ... ). Detection of QTLs associated with antibiosis to green ... rice leafhopper, Nephotettix cincticeps Uhler, in ...

  12. 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.)

  13. Periinterventional prophylactic antibiotics in radiological port catheter implantation

    International Nuclear Information System (INIS)

    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.)

  14. 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.

  15. Evidence that antibiotic of Pantoea agglomerans E325 is produced and active against Erwinia amylovora on stigmas of pomaceous blossoms

    Science.gov (United States)

    Pantoea agglomerans strain E325, the active ingredient in a commercial product for fire blight, previously was shown to produce a unique pH-sensitive inhibitor in vitro that is specific to E. amylovora. To evaluate antibiosis as a mode of antagonism of E325, Tn5 mutagenesis was used to generate...

  16. 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.

  17. Estado actual y perspectivas futuras del estudio de los musgos cubanos

    OpenAIRE

    Motito, Angel; Potrony, María Elena; Montoya, Deisi Reyes

    1992-01-01

    Cuba is one of the Greater Antilles islands with a diverse moss flora (383 infrageneric taxa) that is mainly distributed toward the mountain areas. Although studies on phytochemistry and antibiosis have been initiated, those in taxonomy must be continued at the same time.

  18. 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.

  19. 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 ...

  20. 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.

  1. 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...

  2. 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.

  3. Effect of gamma radiation on arcelin protein and its influence on Zabrotes Subfasciatus (Boheman)

    International Nuclear Information System (INIS)

    The research aimed to evaluate the effect of different doses of gamma radiation on the arcelin protein related to Zabrotes subfasciatus (Boheman) resistance. Seeds of Phaseolus vulgaris L. carrier of arcelin protein and a cv. without this protein, used as control, were irradiated with doses of 0, 0.25, 0.5, 1.0, and 2.0 kGy. After irradiation, the seeds were subjected to confinement test to evaluate different parameters viz. total egg, viable eggs, emerged insects, insect weights, oviposition period and sex ratio. The results showed no influence of radiation doses on the evaluated parameters, and the Arcelin-1 and 2 strains have maintained thus antibiosis grade. The Arcelin-3 and 4, also kept their less expressive behaviour of resistance by antibiosis and only prolonged the oviposition period of the female. (author)

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

    OpenAIRE

    Evandro Leite de Souza; Clemilson Antonio da Silva; Cristina Paiva de Sousa

    2005-01-01

    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 con...

  5. Biocontrol mechanisms of Thrichoderma strains

    OpenAIRE

    Benítez Fernández, Concepción Tahía; Rincón Romero, Ana María; Limón Mirón, María del Carmen; Carballo Codón, Antonio

    2004-01-01

    The genus Trichoderma comprises a great number of fungal strains that act as biological control agents, the antagonistic properties of which are based on the activation of multiple mechanisms. Trichoderma strains exert biocontrol against fungal phytopathogens either indirectly, by competing for nutrients and space, modifying the environmental conditions, or promoting plant growth and plant defensive mechanisms and antibiosis, or directly, by mechanisms such as mycoparasitism. These indirect a...

  6. Induced Systemic Resistance and the Rhizosphere Microbiome

    OpenAIRE

    Bakker, Peter A. H. M.; Doornbos, Rogier F.; Zamioudis, Christos; Berendsen, Roeland L.; Pieterse, Corné M. J.

    2013-01-01

    Microbial communities that are associated with plant roots are highly diverse and harbor tens of thousands of species. This so-called microbiome controls plant health through several mechanisms including the suppression of infectious diseases, which is especially prominent in disease suppressive soils. The mechanisms implicated in disease suppression include competition for nutrients, antibiosis, and induced systemic resistance (ISR). For many biological control agents ISR has been recognized...

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

    OpenAIRE

    Yongming Sang; Frank Blecha

    2014-01-01

    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 ...

  8. Effect of Growth of Selected Lactic Acid Bacteria on Microbial Flora of Ground Beef under Workshop Conditions

    OpenAIRE

    F. Akbari Nakhjavani; H. Lamea; Sh. Darvishi; F Darvish

    2004-01-01

    The effects of growth of two strains of lactic acid bacteria on microbial flora of ground beef after packaging in air permeable packs were studied under workshop conditions. The strains isolated from dairy products were added to ground beef at a density of 104 CFU/g after identification and antibiosis test against indicator bacteria (Escherichia coli and Staphylococcus aureus). The two strains were Lactobacillus casei subsp. casei 102, and Lactococcus lactis subsp. lactis var. diacetylactis 2...

  9. 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

  10. Molecular detection of antibiotic related genes from Pseudomonas aeruginosa FP6, an antagonist towards Rhizoctonia solani and Colletotrichum gloeosporioides

    OpenAIRE

    BAKTHAVATCHALU, Sasirekha; Shivakumar, Srividya; SULLIA, Shankar Bhat

    2013-01-01

    Despite the importance of antibiosis in biological control, little is known about the genes involved in antifungal activity. Therefore, the present study was aimed at identifying the location of the antagonistic gene(s) in Pseudomonas aeruginosa FP6 towards Rhizoctonia solani and Colletotrichum gloeosporioides using a PCR-based approach. A new bacterial strain, designated as FP6, was isolated from rhizospheric soil and identified as a member of Pseudomonas aeruginosa based on 16S rRNA analysi...

  11. 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

  12. 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

  13. 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)

  14. In vitro antagonistic activity of fungi isolated from sclerotia on potato tubers against Rhizoctonia solani

    OpenAIRE

    DEMİRCİ, Erkol; DANE, Elif; Eken, Cafer

    2011-01-01

    Forty-five fungal isolates were obtained from sclerotia of Rhizoctonia solani on potato tubers in Erzurum, Turkey. The interaction between fungal isolates and R. solani was studied in dual culture technique. Some fungal isolates affected R. solani by antibiosis and/or parasitism. Results of the antagonism tests showed that Acremonium sp., Gliocladium viride, Paecilomyces marquandii, Paecilomyces sulphurellus, Penicillium camemberti, Penicillium expansum, Penicillium frequentans (ME-50), Penic...

  15. 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 ...

  16. 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.

  17. 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)

  18. 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

  19. 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.

  20. Aislamiento, caracterización y análisis funcional del gen "Thpg1" de "Trichoderma harzianum"

    OpenAIRE

    Morán Díez, María Eugenia

    2008-01-01

    Muchas especies del género Trichoderma son utilizadas como agentes de control biológico en agricultura. En este sentido, se han propuesto varios mecanismos de acción como el micoparasitismo, la antibiosis y la competencia por el espacio. Parte de la actividad antagonista de este agente de biocontrol está basada en la secreción de enzimas, como quitinasas o glucanasas, que participan en la penetración del patógeno. Sin embargo, en los últimos años se está prestando una mayor atención a la rela...

  1. 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

  2. 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...

  3. Phytochemical and biological studies of plants from the genus Meconopsis.

    Science.gov (United States)

    Li, Mao-Xing; Wang, Jin-Hui; He, Xi-Rui; Fan, Peng-Cheng; Zhang, Ru-Xue; Jia, Zheng-Ping

    2010-08-01

    In this review, the literature data on the phytochemical and biological investigations on the genus of Meconopsis are summarized from 49 references. Up to now, more than 95 compounds were isolated from 19 Meconopsis plant species. The chemical constituents are mostly alkaloids, flavonoids, phenols, steroids, and terpenes, together with minor constituents of essential oil, and others. The crude extracts and metabolites have been found to possess various bioactivities including antitumor activity, central action, cardiovascular system effects, antibiosis, antiviral activity, anti-inflammatory effects, and other biological activities. PMID:20730958

  4. [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

  5. 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...

  6. 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. ...

  7. Inhibidores de α- amilasas de la broca del cafe Hypothenemus hampei en diferentes especies de vegetales α-Amylase inhibitors of the cofee berry borer Hypothenemus hampei in different plant species

    OpenAIRE

    Beatriz Elena Padilla; José Ricardo Acuña Z; Claudia S Velásquez; José David Rubio G

    2006-01-01

    La antibiosis es uno de los mecanismos de resistencia de las plantas al ataque de insectos, en el cual están involucradas proteínas de defensa como los inhibidores de α- amilasas. Estas se encuentran principalmente en especies vegetales como gramíneas y leguminosas. En Phaseolus vulgaris L. var radical se ha registrado un inhibidor de α- amilasas de la broca del café Hypothenemus hampei, con más de 80% de inhibición, el cuál también inhibe las α- amilasas de mamíferos. Siend...

  8. 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.

  9. Alternatives to antibiotics in animal agriculture: an ecoimmunological view.

    Science.gov (United States)

    Sang, Yongming; Blecha, Frank

    2014-01-01

    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. PMID:25551290

  10. Cyclic lipopeptide profile of three Bacillus subtilis strains; antagonists of Fusarium head blight.

    Science.gov (United States)

    Dunlap, Christopher A; Schisler, David A; Price, Neil P; Vaughn, Steven F

    2011-08-01

    The objective of the study was to identify the lipopetides associated with three Bacillus subtilis strains. The strains are antagonists of Gibberella zeae, and have been shown to be effective in reducing Fusarium head blight in wheat. The lipopeptide profile of three B. subtilis strains (AS43.3, AS43.4, and OH131.1) was determined using mass spectroscopy. Strains AS43.3 and AS43.4 produced the anti-fungal lipopeptides from the iturin and fengycin family during the stationary growth phase. All three strains produced the lipopeptide surfactin at different growth times. Strain OH131.1 only produced surfactin under these conditions. The antifungal activity of the culture supernatant and individual lipopeptides was determined by the inhibition of G. zeae. Cell-free supernatant from strains AS43.3 and AS43.4 demonstrated strong antibiosis of G. zeae, while strain OH131.1 had no antibiosis activity. These results suggest a different mechanism of antagonism for strain OH131.1, relative to AS43.3 and AS43.4. PMID:21887643

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. Mycoparasitic and Antagonistic Inhibition on Phytophthora cinnamomi Rands by Microbial Agents Isolated from Manure Composts

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    I. Nyoman Pugeg Aryantha

    2006-01-01

    Full Text Available We isolated bacteria and fungi from composted chicken, sheep, cow and horse manure and screened each isolate for their ability to suppress P. cinnamomi in dual-culture in vitro assays. Of the 180 isolates, including 31 actinomycetes, 64 fungi, 44 fluorescent pseudomonads and 41 endospore-forming bacteria, 45 isolates significantly inhibited the growth of P. cinnamomi on plates. The inhibitory microbes included 24 fungi (including Trichoderma sp., Gliocladium penicillioides and Fusarium sp., 0 actinomycetes (all Streptomyces sp., 7 fluorescent pseudomonads (Pseudomonas sp. and 4 endospore-forming bacteria (Bacillus sp.. The most common mode of action observed was antibiosis, although mycoparasitism, indicated by parallel hyphal growth, hyphal coiling, appressorium formation and direct penetration, was also observed with one isolate of Trichoderma. These results help to explain the role of microbes in the suppression and biological control of P. cinnamomi by composted manures.

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

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    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. .

  2. 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

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    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.

  3. 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.

  4. 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.

  5. 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%.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. Seleção de genótipos de capim-elefante quanto à resistência à cigarrinha-das-pastagens Selection of elephant grass genotypes for resistance to spittlebug

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    Alexander Machado Auad

    2007-08-01

    Full Text Available O objetivo deste trabalho foi avaliar genótipos de capim-elefante (Pennisetum purpureum Schum. quanto à resistência à cigarrinha-das-pastagens (Mahanarva spectabilis. Para avaliação da antibiose, aos trinta dias após o plantio, cada planta foi infestada com seis ovos próximos à eclosão, em delineamento inteiramente casualizado, com 30 genótipos e dez repetições. Quarenta e cinco dias após a eclosão das ninfas, avaliou-se a porcentagem de sobrevivência do inseto-praga nos diferentes genótipos. Para avaliação da não-preferência, foram quantificados, quinzenalmente, o número e tamanho de ninfas por vaso, em plantas mantidas em casa de vegetação, onde adultos de M. spectabilis eram periodicamente liberados, em delineamento inteiramente casualizado, com três repetições por genótipo, em dois períodos de amostragem. Os genótipos Cameroon de Piracicaba, Pioneiro, Cuba 169, Santa Rita, Mineiro Ipeaco, Mercker Comum de Pinda e CNPGL 96-27-3 foram selecionados quanto à resistência, pelo mecanismo de antibiose. O número e o tamanho médio das ninfas variaram significativamente em razão do genótipo de capim-elefante, no estudo da não-preferência. Os genótipos Roxo de Botucatu e Pioneiro são candidatos à testemunha suscetível e resistente, respectivamente, pelo mecanismo de antibiose, e os genótipos Cameroon e Cameroon Piracicaba são promissores pelo mecanismo de não-preferência.The objective of this work was to evaluate genotypes of elephant grass (Pennisetum purpureum Schum. regarding resistance to the spittlebug Mahanarva spectabilis. For antibiosis evaluation, each plant was infested with six eggs near hatching, thirty days after planting, in a completely randomized design with 30 genotypes and ten repetitions. Forty-five days after the nymphs hatched, the insect survival rate was evaluated on the different genotypes. For nonpreference mechanism evaluation, the size and number of the nymphs per pot were

  14. 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

  15. 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.

  16. Parâmetros biológicos de Bemisia Tabaci (genn. biótipo B (hemiptera: aleyrodidae em genótipos de algodoeiro Biological parameters of Bemisia Tabaci B biotype on cotton genotypes

    Directory of Open Access Journals (Sweden)

    Zeneide Ribeiro Campos

    2009-01-01

    Full Text Available A mosca-branca Bemisia tabaci biótipo B é uma praga de grande importância econômica para muitas culturas em todo o mundo. No Brasil, especialmente no Estado da Bahia, essa praga causou perdas que variam entre 30% e 70% em cultura de algodão. Essa pesquisa foi desenvolvida com o objetivo de avaliar parâmetros biológicos de B. tabaci biótipo B em genótipos de algodoeiro para verificar a possível ocorrência de antibiose como mecanismo de resistência sob condições de casa de vegetação. Os genótipos estudados foram IAC-23, Coodetec 406, BRS Aroeira, Fabrika, Coodetec 407, IAC-24, Makina, IAC 20-233, Coodetec 401 e CNPA Acala I. Foram avaliados os períodos de incubação e ninfal, o desenvolvimento total e a longevidade. Dos genótipos avaliados observou-se em Coodetec 406 maior período ninfal (14,7 dias e IAC-23 a menor viabilidade de ninfas (30,7%, indicando a ocorrência de resistência do tipo antibiose contra essa mosca-branca.The silverleaf whitefly Bemisia tabaci B biotype is an important pest of many crops throughout the world. In Brazil, specifically in the Bahia State, this insect caused losses estimated to 30-70% on cotton crops. The purpose of this research was to investigate biological parameters of the silverleaf whitefly biotype B in genotype of cotton bush to verify a possible occurrence of antibiosis as resistance mechanism cotton, under greenhouse conditions. The duration of the egg and nymphal stages, and the adult longevity of B. tabaci biotype B were evaluated in the genotypes IAC-23, Coodetec 406, BRS Aroeira, Fabrika, Coodetec 407, IAC-24, Makina, IAC 20-233, Coodetec 401 and CNPA Acala I. Among those evaluated genotypes, Coodetec 406 increased the nymph stage (14.7 days and IAC-23 reduced the nymphal viability (30.7%, suggesting the occurrence of antibiosis against this whitefly.

  17. 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% < R (2) < 27%). The loci were within the intervals Satt632-A2D8 on linkage group (LG) A2 (chromosome 8); Satt583-Satt415 on LG B1 (11); Satt009-Satt530 on LG N (3); and close to two markers OB02_140 (LG E; 20 cM from Satt572) and OZ15_150 LG (19 cM from Satt291 C2). Two QTL were detected for the mean PI field trait (16% < R (2) < 18%) close to Satt385 on LG A1 and Satt440 on LG I. The no choice feeding studies detected three QTL that were significant; two for antixenosis (22% < R (2) < 24%) between Satt632-A2D8 on LG A2 (8) and Sat_039-Satt160 on LG F (13); and a major locus effect (R (2) = 54%) for antibiosis on LG D2 (17) between Satt464-Satt488. Therefore, loci underlying resistance to JB herbivory were a mixture of major and minor gene effects. Some loci were within regions underlying resistance to soybean cyst nematode (LGs A2 and I) and root knot nematode (LG F) but not other major loci underlying

  18. Morphological, Physiological, and Taxonomic Characterization of Actinobacterial Isolates Living as Endophytes of Cacao Pods and Cacao Seeds.

    Science.gov (United States)

    Tchinda, Romaric Armel Mouafo; Boudjeko, Thaddée; Simao-Beaunoir, Anne-Marie; Lerat, Sylvain; Tsala, Éric; Monga, Ernest; Beaulieu, Carole

    2016-03-26

    Vascular plants are commonly colonized by endophytic actinobacteria. However, very little is known about the relationship between these microorganisms and cacao fruits. In order to determine the physiological and taxonomic relationships between the members of this community, actinobacteria were isolated from cacao fruits and seeds. Among the 49 isolates recovered, 11 morphologically distinct isolates were selected for further characterization. Sequencing of the 16S rRNA gene allowed the partition of the selected isolates into three phylogenetic clades. Most of the selected endophytic isolates belonged to the Streptomyces violaceusniger clade. Physiological characterization was carried out and a similarity index was used to cluster the isolates. However, clustering based on physiological properties did not match phylogenetic lineages. Isolates were also characterized for traits commonly associated with plant growth-promoting bacteria, including antibiosis and auxin biosynthesis. All isolates exhibited resistance to geldanamycin, whereas only two isolates were shown to produce this antibiotic. Endophytes were inoculated on radish seedlings and most isolates were found to possess plant growth-promoting abilities. These endophytic actinobacteria inhibited the growth of various plant pathogenic fungi and/or bacteria. The present study showed that S. violaceusniger clade members represent a significant part of the actinobacterial community living as endophytes in cacao fruits and seeds. While several members of this clade are known to be geldanamycin producers and efficient biocontrol agents of plant diseases, we herein established the endophytic lifestyle of some of these microorganisms, demonstrating their potential as plant health agents. PMID:26947442

  19. 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.

  20. 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。

  1. 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

  2. Phylogenetic diversity and antimicrobial activities of bryozoan-associated bacteria isolated from Mediterranean and Baltic Sea habitats.

    Science.gov (United States)

    Heindl, Herwig; Wiese, Jutta; Thiel, Vera; Imhoff, Johannes F

    2010-03-01

    To date, only a small number of investigations covering microbe-bryozoa associations have been carried out. Most of them have focused on a few bryozoan species and none have covered the antibacterial activities of associated bacteria. In the current study, the proportion and phylogenetic classification of Bryozoan-associated bacteria with antimicrobial properties were investigated. Twenty-one specimens of 14 different bryozoan species were collected from several sites in the Baltic and the Mediterranean Sea. A total of 340 associated bacteria were isolated, and 101 displayed antibiotic activities. While antibiosis was predominantly directed against Gram-positive test strains, 16S rRNA gene sequencing revealed affiliation of the isolates to Gram-negative classes (Flavobacteria, Alpha- and Gammaproteobacteria). One isolate was related to the Gram-positive Actinobacteria. The sequences were grouped into 27 phylotypes on the basis of similarity values >or=99.5%. A host-specific affiliation was not revealed as members of the same phylotype were derived from different bryozoan species. Site-specific patterns, however, were demonstrated. Strains of the genera Sphingomonas and Alteromonas were exclusively isolated from Mediterranean sites, whereas Shewanella, Marinomonas and Vibrio-related isolates were only from Baltic sites. Although Pseudoalteromonas affiliated strains were found in both habitats, they were separated into respective phylotypes. Isolates with 16S rDNA similarity values Tenacibaculum. PMID:20153592

  3. Antagonismo direto e biocontrole da podridão-mole-do-tomateiro pelo uso de procariotas Direct antagonism and biocontrol of tomato soft rot using prokaryotes

    Directory of Open Access Journals (Sweden)

    Victor Rafael Barra

    2009-03-01

    Full Text Available O objetivo deste trabalho foi avaliar procariotas quanto ao potencial de antagonismo direto para o biocontrole da podridão-mole-do-tomateiro (Pectobacterium carotovorum subsp. carotovorum. Avaliaram-se 45 isolados bacterianos pelo teste de antibiose contra o patógeno. Foram feitos dois ensaios em que sementes de tomate (Lycopersicon esculentum Mill. cv. Santa Clara foram infectadas com isolados antagônicos. As mudas foram transplantadas para solos infestados com suspensões de propágulos P. carotovorum com OD540 de 0,45 e 0,65. Os antagonistas UFV-0005, UFV-043, UFV-BF112 e UFV-0006 foram eficientes em proteger plantas de tomateiro contra a podridão-mole.This work aimed to evaluate prokaryotes to provide direct antagonism and biocontrol of tomato soft rot (Pectobacterium carotovorum subsp. carotovorum. Forty-five bacterial isolates previously selected for biological control of several tomato (Lycopersicon esculentum Mill. diseases were evaluated using an antibiosis test. 'Santa Clara' tomato seeds were inoculated with potential antagonist isolates and transplanted to a soil infested with the pathogen, in two asseys, at a propagule concentration of OD540 0.45 and 0.65. Antagonists UFV-0005, UFV-043, UFV-BF112, and UFV-0006 protected tomato plants against soft rot disease.

  4. 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。

  5. [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

  6. [Optimization model of spatial population structure: example of poplar moth laying eggs on leaves].

    Science.gov (United States)

    Sekretenko, O P; Sukhovol'skiĭ, V G; Tarasova, O V

    2002-01-01

    The authors analyze spatial distribution and survival of populations of poplar moth Litchcolletis populifoliella Tr. on its feeding plant--balsam poplar Populus balsamifera. Imago of the moth glue its eggs on the leaves thus determining the future location of their offspring on the host plant. Spatial distribution of eggs on leaf surface and distribution of leaves according egg numbers are not random. On the short distance from each egg the average number of eggs is less, than it should be in case of random distribution. While this distance increases up to some particular value the occurrence of eggs is higher than random. Thus, the eggs of moth are located by groups on the leaf surface. Within each group eggs are situated not very close to each other, this allowing larvae to lower competition for common resource. It is suggested that on the same feeding plant individuals have different interactions: competition, caused by limited quantity of resource and cooperation that is necessary to resist leaf defensive (antibiosis) reaction. PMID:12298182

  7. Genetic evaluation of two aphid resistant cowpea mutants in Kenya

    International Nuclear Information System (INIS)

    The aphid, Aphis craccivora Koch, is serious pest of cowpea, Vigna unguiculata (L.) Walp., in Africa. It feeds on young shoots by sucking sap, resulting in the stunting and killing of the plant. Several insecticides are effective against aphids, but resistant cultivars offer the most effective and cheapest means of control. Two aphid resistant mutants, ICV11 and ICV12, were developed from the M2 population of ICV1 seeds irradiated with 20 kR of gamma rays. Both mutants showed monogenic dominant inheritance of resistance. Crosses between these mutants and two other cultivars, ICV10 and TVu310, indicated that ICV11 and ICV12 contain another dominant resistance gene which is non-allelic to the resistance gene in ICV10 and TVu310. The genes were designated Racl (in ICV10 and TVu310) and Rac2 (in ICV11 and ICV12). Both antixenosis and antibiosis types of resistance mechanism were found to be operating in the mutant cultivars. The improved attributes of the mutant cultivars ICV11 and ICV12 were a high level of resistance to aphid, an increased pod length, an increased number of seeds per pod, a semi-erect plant type and higher grain yields. (author). 14 refs, 2 figs, 2 tabs

  8. Response of tomato wilt pathogen Ralstonia solanacearum to the volatile organic compounds produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9

    Science.gov (United States)

    Raza, Waseem; Ling, Ning; Yang, Liudong; Huang, Qiwei; Shen, Qirong

    2016-01-01

    It is important to study the response of plant pathogens to the antibiosis traits of biocontrol microbes to design the efficient biocontrol strategies. In this study, we evaluated the role of volatile organic compounds (VOCs) produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum (RS). The VOCs of SQR-9 significantly inhibited the growth of RS on agar medium and in soil. In addition, the VOCs significantly inhibited the motility traits, production of antioxidant enzymes and exopolysaccharides, biofilm formation and tomato root colonization by RS. The strain SQR-9 produced 22 VOCs, but only nine VOCs showed 1–11% antibacterial activity against RS in their corresponding amounts; however, the consortium of all VOCs showed 70% growth inhibition of RS. The proteomics analysis showed that the VOCs of SQR-9 downregulated RS proteins related to the antioxidant activity, virulence, carbohydrate and amino acid metabolism, protein folding and translation, while the proteins involved in the ABC transporter system, amino acid synthesis, detoxification of aldehydes and ketones, methylation, protein translation and folding, and energy transfer were upregulated. This study describes the significance and effectiveness of VOCs produced by a biocontrol strain against tomato wilt pathogen. PMID:27103342

  9. Rhizobacteria activates (+)-δ-cadinene synthase genes and induces systemic resistance in cotton against beet armyworm (Spodoptera exigua).

    Science.gov (United States)

    Zebelo, Simon; Song, Yuanyuan; Kloepper, Joseph W; Fadamiro, Henry

    2016-04-01

    Gossypol is an important allelochemical produced by the subepidermal glands of some cotton varieties and important for their ability to respond to changing biotic stress by exhibiting antibiosis against some cotton pests. Plant growth-promoting rhizobacteria (PGPR) are root-colonizing bacteria that increase plant growth and often elicit defence against plant pathogens and insect pests. Little is known about the effect of PGPR on cotton plant-insect interactions and the potential biochemical and molecular mechanisms by which PGPR enhance cotton plant defence. Here, we report that PGPR (Bacillus spp.) treated cotton plants showed significantly higher levels of gossypol compared with untreated plants. Similarly, the transcript levels of the genes (i.e. (+)-δ-cadinene synthase gene family) involved in the biosynthesis of gossypol were higher in PGPR-treated plants than in untreated plants. Furthermore, the levels of jasmonic acid, an octadecanoid-derived defence-related phytohormone and the transcript level of jasmonic acid responsive genes were higher in PGPR-treated plants than in untreated plants. Most intriguingly, Spodoptera exigua showed reduced larval feeding and development on PGPR-treated plants. These findings demonstrate that treatment of plants with rhizobacteria may induce significant biochemical and molecular changes with potential ramifications for plant-insect interactions. PMID:26715260

  10. 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.

  11. Secondary metabolites from endophytic Streptomyces aureofaciens CMUAc130 and their antifungal activity.

    Science.gov (United States)

    Taechowisan, Thongchai; Lu, Chunhua; Shen, Yuemao; Lumyong, Saisamorn

    2005-05-01

    Streptomyces aureofaciens CMUAc130 was isolated from the root tissue of Zingiber officinale Rosc. (Zingiberaceae). It was an antagonist of Colletotrichum musae and Fusarium oxysporum, the causative agents of anthracnose of banana and wilt of wheat, respectively. Evidence for the in vitro antibiosis of S. aureofaciens CMUAc130 was demonstrated by the zone of fungal-growth inhibition. Microscopic observations showed thickness and bulbous structures at the edges of the inhibited fungal hyphae. The culture filtrate and crude extract from this strain were all inhibitory to tested phytopathogenic fungi. The major active ingredients from the culture filtrate of S. aureofaciens CMUAc130 were purified by silica gel-column chromatography and identified to be (i) 5,7-dimethoxy-4-p-methoxylphenylcoumarin and (ii) 5,7-dimethoxy-4-phenylcoumarin by NMR and mass-spectral data, respectively. Bioassay studies showed that compounds (i) and (ii) had antifungal activities against tested fungi, and their MICs were found to be 120 and 150 microg ml(-1), respectively. This is the first report of compounds (i) and (ii) from micro-organisms as active ingredients for the control of phytopathogenic fungi. PMID:15870476

  12. 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.

  13. Cepas nativas del bacterioneuston marino y su actividad inhibitoria de bacterias ictiopatógenas

    Directory of Open Access Journals (Sweden)

    Jorge León

    2014-06-01

    Full Text Available En la literatura científica, las bacterias marinas han sido consideradas con frecuencia como productores de sustancias antibacterianas. En este estudio, se investigó el potencial de actividad antibiótica in vitro de cepas nativas de bacterioneuston marino aisladas de las pozas intermareales de Montemar, Bahía de Valparaiso, Chile. Se aislaron 71 cepas neustónicas antagonistas a Staphylococcus aureus ATCC 11632. Veinticinco de ellas, productoras de sustancias fuertemente inhibitorias, fueron evaluadas por su antagonismo frente a una colección de 15 bacterias ictiopatógenas. Aplicando métodos clásicos para bacterias marinas, se caracterizaron fenotípicamente orientados a la identificación. Los resultados de antibiosis indican que la totalidad cle las ictiopatógenas en prueba son susceptibles a la actividad inhibitoria de las cepas neustónicas, siendo V anguillarum NCMB 2133, V ordalii 84/2559 y V tubiashii EX1 las más sensibles. Entre las cepas aisladas del neuston se identificaron miembros de los géneros Vibrio spp. (28%, Flavobacterium spp. (12%, Alteromonas-Marinomonas (12%, Pseudomonas spp (8% y Micrococcus spp, (4%. Nueve cepas (36% no fueron identificadas. Los resultados de actividades inhibitorias frente a ictiopatógenos sugieren que dichas cepas o sus productos pudieran ser útiles en actividades de cultivos intensivos de maricultura de peces, moluscos y crustáceos.

  14. Iturin levels on wheat spikes linked to biological control of Fusarium head blight by Bacillus amyloliquefaciens.

    Science.gov (United States)

    Crane, J M; Gibson, D M; Vaughan, R H; Bergstrom, G C

    2013-02-01

    The TrigoCor strain of Bacillus amyloliquefaciens provides consistent control against Fusarium head blight of wheat in controlled settings but there is a lack of disease and deoxynivalenol suppression in field settings. Since production of antifungal compounds is thought to be the main mode of action of TrigoCor control, we quantified levels of a key family of antifungal metabolites, iturins, as well as monitored Bacillus populations on wheat spikes over 14 days post-application in both the greenhouse and the field. We found that initial iturin levels on spikes in the greenhouse were three times greater than on spikes in the field, but that by 3 days post-application, iturin levels were equivalent and very low in both settings. We also determined that iturins declined rapidly over a 3-day post-application period on wheat spikes in both environments, despite the presence of significant Bacillus populations. Greenhouse trials and antibiosis tests indicated that the lower iturin levels on wheat spikes in the field could be a major factor limiting disease control in field settings. Future efforts to improve Bacillus disease control on wheat spikes and in the phyllosphere of various plants should focus on maintaining higher levels of iturins over critical infection periods. PMID:23075168

  15. 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.

  16. 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

  17. 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

  18. Response of tomato wilt pathogen Ralstonia solanacearum to the volatile organic compounds produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9.

    Science.gov (United States)

    Raza, Waseem; Ling, Ning; Yang, Liudong; Huang, Qiwei; Shen, Qirong

    2016-01-01

    It is important to study the response of plant pathogens to the antibiosis traits of biocontrol microbes to design the efficient biocontrol strategies. In this study, we evaluated the role of volatile organic compounds (VOCs) produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum (RS). The VOCs of SQR-9 significantly inhibited the growth of RS on agar medium and in soil. In addition, the VOCs significantly inhibited the motility traits, production of antioxidant enzymes and exopolysaccharides, biofilm formation and tomato root colonization by RS. The strain SQR-9 produced 22 VOCs, but only nine VOCs showed 1-11% antibacterial activity against RS in their corresponding amounts; however, the consortium of all VOCs showed 70% growth inhibition of RS. The proteomics analysis showed that the VOCs of SQR-9 downregulated RS proteins related to the antioxidant activity, virulence, carbohydrate and amino acid metabolism, protein folding and translation, while the proteins involved in the ABC transporter system, amino acid synthesis, detoxification of aldehydes and ketones, methylation, protein translation and folding, and energy transfer were upregulated. This study describes the significance and effectiveness of VOCs produced by a biocontrol strain against tomato wilt pathogen. PMID:27103342

  19. 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.

  20. 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)

  1. 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.

  2. 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

  3. 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)

  4. 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

  5. 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

  6. Antifouling effect of bioactive compounds from selected marine organisms in the Obhur Creek, Red Sea

    Science.gov (United States)

    Al-Sofyani, Abdulmohsin; Marimuthu, N.; Wilson, J. Jerald; Pugazhendi, Arulazhagan; Dhavamani, Jeyakumar

    2016-06-01

    Three species of sponges and a tunicate were collected from Obhur creek of Jeddah coast for this bioactivity study. In order to assess the antifouling efficacy of selected marine organisms, methanolic extracts of these organisms were tested against different fouling bacterial forms and II-instar stage of the barnacle, Balanus amphitrite. Antibiosis, bioactivity and followed by multivariate analyses were carried out to check the efficacy of antifouling effect of the selected marine organisms. Principal component analysis revealed the exemplary antifouling efficacy of the sponge extracts of Stylissa sp. observed followed by Hyrtios sp. against bacterial forms in the laboratory study. De-trended correspondence analysis confirmed that the contribution of antifouling efficacy of the selected sponge extracts was observed to be more towards Bacillus sp., Vibrio sp. and Alteromonas sp. Moreover, the efficacy of Hyrtios sp. extract (20.430 μg mL-1) followed by Stylissa sp. (30.945 μg mL-1) showed higher against barnacle instar compared with other extracts in the bioactivity assay. Bray-Curtis cluster analysis under paired linkage categorized all the sponge extracts into one major cluster with 75% similarity, and one outlier tunicate. More than 80% similarity observed between Hyrtios sp. and Stylissa sp. Fourier transform infrared spectroscopy (FTIR) showed that the contribution of major peaks found in the marine organisms were towards sulfones, sulfoxides, cyanates and ketones.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Biological aspects of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on six bean genotypes

    International Nuclear Information System (INIS)

    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)

  12. 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:

  13. 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.

  14. 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

  15. Selection of processing tomato genotypes with high acyl sugar content that are resistant to the tomato pinworm.

    Science.gov (United States)

    Dias, D M; Resende, J T V; Faria, M V; Camargo, L K P; Chagas, R R; Lima, I P

    2013-01-01

    Acyl sugars are allelochemicals present at high concentrations in leaves of accessions of the wild tomato Solanum pennellii; they confer resistance to a large number of arthropod pests, including the tomato pinworm, Tuta absoluta (Lepidoptera, Gelechiidae). Accession 'LA716', with high contents of acyl sugars in the leaves, was used as a source of resistance to start a genetic breeding program of processing cultivated tomato, S. lycopersicum. We selected plants of the F₂ generation of an interspecific cross (S. lycopersicum cv. 'Redenção' x S. pennellii 'LA716') for extremes of concentrations (high and low) of acyl sugars in the leaves and evaluated the resistance of selected genotypes to the tomato pinworm, compared with plants of the parental and F₁ generations. The concentrations of acyl sugars present in the genotypes selected for high contents were close to those of S. pennellii 'LA 716', while the genotypes with low concentrations of acyl sugars were close to cultivar 'Redenção'. The F₁ hybrid ('Redenção' x 'LA716') had intermediate concentrations of acyl sugars, but was closer to Redenção, indicating that the inheritance of this type of character is due to a recessive major gene, along with minor genes with additive effects. There was a direct association between high contents of acyl sugars and non-preference for oviposition and suppression of larval development, indicating that the allelochemical acts through mechanisms of non-preference for oviposition and through antibiosis. Genotypes with high contents of acyl sugars were more effective in reducing the damage caused by the tomato pinworm. Genotypes RVTA-2010pl#94 and RVTA-2010pl#31, selected for high contents of acyl sugars, showed a good level of resistance to T. absoluta, similar to the wild genotype LA716. These genotypes are promising for use in a breeding program for developing commercial processing tomatoes. PMID:23420362

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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

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    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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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. PMID:21510220

  7. Modelling response patterns of physico-chemical indicators during high-rate composting of green waste for suppression of Pythium ultimum.

    Science.gov (United States)

    St Martin, Chaney C G; Bekele, Isaac; Eudoxie, Gaius D; Bristol, Dexter; Brathwaite, Richard A I; Campo, Kenia-Rosa

    2014-01-01

    High-rate composting studies on green waste, i.e. banana leaves (BL) and lawn clippings (LC), were conducted in 0.25-m3 rotary barrel composters to evaluate and model changes in key physico-chemical parameters during composting. Time to compost maturity and antagonistic effects and relationships of composts against Pythium ultimum were also investigated. Higher temperatures were achieved in LC compost (LCC), which did not translate to higher total organic carbon (TOC) loss but resulted in lower carbon to nitrogen ratio (C:N) and a more mature compost. With the exception of electrical conductivity (EC), net decreases were observed in pH, TOC and C:N across compost types. Total Kjeldahl nitrogen (TKN) showed a net increase in LCC and a net decrease in BLC. With the exception of TOC and pH, the results showed that compost type and time had a significant effect on the respective TKN, EC and C:N models. Compost temperature and TOC were best described by the critical exponential and rectangular hyperbola functions, respectively. Whereas TKN, C:N and pH were described using double Fourier functions and EC using Fourier functions. Composts achieved maturity within 19 days and significantly inhibited the growth of P. ultimum. Bacterial population was positively related to growth inhibition (GI) across compost types, whereas total microbial population had a positive relationship with GI in LCC. Evidence suggests that multiple groups of microorganisms contributed to GI through antibiosis and competition for resources. Composts were determined to be suitable for use as components of plant growth substrates based on compost maturity indices. PMID:24645438

  8. 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.

  9. 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

  10. Resistance of irradiated and non-irradiated corn grain genotypes against the weevil Sitophilus zeamais Mots., 1855 (Coleoptera: Curculionidae)

    International Nuclear Information System (INIS)

    The resistance of 13 /////com grain genotypes was evaluated against the attack of Sitophilus zeamais (Mots.) by means of a no-choice test; 6 of them were selected (AGN 2012, AGN 30AOO, AGN 31A31, AGN 25A23, AGN 32A43, and AGN 35A42) and then submitted to a free-choice test where attractiveness and non preference for oviposition were assessed. The grain from the selected genotypes were later treated with Cobalt-60 gamma radiation at the doses of 0.0; 0.5; 1.0; and 1.5 kGy and submitted to the same tests. Based on the results, it was verified that genotypes AGN 2012 (30.6 eggs), AGN 31A31 (33.6 eggs), and AGN 30AOO (34.8 eggs) showed a non-preference for oviposition type of resistance, while non-preference for feeding and/or antibiosis were observed in the first two genotypes only. Genotypes AGN 25A23, AGN 32A43, and AGN 35A42 were the most susceptible to com weevil. The increasing gamma radiation (60Co) doses reduced the mean mass of adults in genotype AGN 2012; however, the same parameter increased in genotype AGN 35A42; when treated at the dose of 1.5 kGy, genotypes AGN 2012 and AGN 31A31 showed a reduction in their mean masses of adults, while genotypes AGN 30AOO and AGN 35A42 showed higher mean mass of adults values. The increasing gamma radiation doses (60Co) provided a reduction in mean grain dry mass consumed by the weevil; however, it was concluded that irradiation did not break com grain resistance and can be used for S. zeamais disinfestation prior to storage. (author)

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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)

  16. Induced mutations for resistance to aphid (Aphis craccivora Koch) in cowpea

    International Nuclear Information System (INIS)

    Aphid is a major insect pest of cowpea and causes heavy yield losses throughout the world. Two mutants, ICV11 and ICV12, resistant to aphids were developed from the M3 generation of ICV1 seeds irradiated with 20 kR of gamma rays. These mutants are true breeding and have a high level of seedling resistance to aphids under screenhouse conditions. The mutants have a high level of antibiosis, causing the death of the pest. They have improved plant type (semi-erect) and longer pod size (20 cm), with 19 seeds, compared with ICV1, which has a pod size of 14 cm with 13 seeds. However, the mutants are late in flowering and maturity compared with the control ICV1. Grain yields of mutants under 'unspread' field conditions are rather low, but they could give higher yields if planted early or protected from other insects using insecticides. The genetics of resistance of mutants was studied in crosses with the susceptible ICV1 and other resistant cultivars. Five day old seedlings were infested with ten aphids per plant in the screenhouse. The reactions of the F1, F2 and BC1 (F1 back-crossed to the susceptible parent ICV1) populations from the crosses of the resistant mutant ICV11 with ICV1 revealed that resistance was governed by a single dominant gene. Analyses of the allelic relationship of the gene for resistance in ICV11 were undertaken in the F1 and F2 populations from the crosses of ICV11 with other resistant cultivars TVu310 and ICV10. Results indicated that the single dominant genes of TVu310 and ICV10 are the same and allelic, while the single dominant gene of the mutant cultivar ICV11 is non-allelic to, and independent of, the resistance genes of TVu310 and ICV10. The dominant gene of TVu310 and ICV10 is designated as Ac1, while the dominant gene of ICV11 is designated as Ac2. Use of resistance genes in breeding for aphid resistance is discussed. (author). 19 refs, 3 figs, 9 tabs

  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

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    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. 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.

  19. Progênies de seringueira com potencial para conferir resistência a ácaros (Calacarus heveae Feres e Tenuipalpus heveae Baker Rubber tree progenies with potential to confer resistance to the mite (Calacarus heveae Feres e Tenuipalpus heveae Baker

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    Marineide Rosa Vieira

    2009-10-01

    preference and/or antibiosis resistance or tolerance to at least one species and should be multiplied for new evaluations in the future.

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. Controle biológico da mancha-aquosa do melão por compostos bioativos produzidos por Bacillus spp. Biocontrol of bacterial fruit blotch of melon by bioactive compounds produced by Bacillus spp.

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    Elizama Roza Santos

    2006-09-01

    presence of bioactive compounds produced during fermentations. All treatments were different from the control (P = 0.05% but they did not differ among them. The B. megaterium pv. cerealis RAB7 reduced disease incidence (89.1%, disease index (92.7%, increased the incubation period from 9.8 to 11.9 days and reduced the area under disease progress curve from 3.36 to 0.17. In the in vitro tests, all strains showed antibiosis against Aac and the bioactive compounds were partially characterized as lipopeptides.

  8. Effect of arcelin protein on the biology of Zabrotes subfasciatus (Boheman 1833, in dry beans Efeito da proteína arcelina na biologia de Zabrotes subfasciatus (Boheman 1833, em feijoeiro

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    Flávia Rabelo Barbosa

    1999-10-01

    Full Text Available Arcelin is a seed protein found in wild beans (Phaseolus vulgaris which gives resistance to Mexican bean weevil, Zabrotes subfasciatus (Boheman 1833 (Coleoptera: Bruchidae. Studies were carried out with the objective of estimating the effect of four alleles of protein arcelin (Arc1, Arc2, Arc3 and Arc4 on the biology of Z. subfasciatus. The experiment was carried out in laboratory at Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, in Santo Antônio de Goiás, GO, Brazil, under non controlled conditions. The highest levels of antibiosis to Z. subfasciatus were observed in Arc1, with reduction in the number of eggs, number of emerged adults, adults longevity. In the line Arc2 only reduction in the number of emerged adults was observed. The lines Arc3 and Arc4 showed low efficiency on the reduction of progeny of Z. subfasciatus and effects in the longevity and egg-adult cycle were not detected. Insect sexual ratio was not altered by the presence of Arc1, Arc2, Arc3 and Arc4 in the seeds.A arcelina é uma proteína encontrada em feijões silvestres (Phaseolus vulgaris e que confere resistência ao caruncho-do-feijão, Zabrotes subfasciatus (Boheman 1833 (Coleoptera: Bruchidae. Estudos foram conduzidos com o objetivo de conhecer o efeito de quatro alelos da proteína arcelina (Arc1, Arc2, Arc3 e Arc4, na biologia de Z. subfasciatus. O experimento foi conduzido no laboratório da Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, no município de Santo Antônio de Goiás, GO, em condições não controladas. O mais alto nível de antibiose a Z. subfasciatus foi constatado na linhagem portadora do alelo Arc1, observando-se redução do número de ovos produzidos, redução do número de adultos emergidos, redução da longevidade de adultos. Na linhagem Arc2 constatou-se redução apenas no número de adultos emergidos. As linhagens Arc3 e Arc4 apresentaram baixa eficiência na redução da progênie de Z. subfasciatus, não observando

  9. Biology of Anticarsia gemmatalis on soybean genotypes with different degrees of resistance to insects Biologia de Anticarsia gemmatalis em genótipos de soja com diferentes graus de resistência a insetos

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    Cristina Gomes Quevedo Fugi

    2005-01-01

    Full Text Available A knowledge of the mechanisms of resistance present in genetic materials should help breeding programs in developing cultivars resistant to insects. The biology of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae was studied on leaves of four soybean genotypes with different degrees of resistance to insects. The genotypes evaluated were cultivars IAC 17 and IAC 24, resistant to defoliators and stink bugs, line PI 229358, a source of multiple resistance to insects and used as parent in various lines selected for resistance to A. gemmatalis, and 'IAC PL-1', the susceptible control. The experiments were carried out in the laboratory, under controlled conditions of temperature (25 ± 2ºC, relative humidity (60 ± 10% and photoperiod (14h. First instar larvae were placed in Petri dishes and fed leaves of each genotype, detached from plants at the R1 and R2 stages (beginning and full bloom. Later on, insect couples were maintained in 25 PVC cages to evaluate parameters of the adult stage. 'IAC 17' and 'IAC 24' promoted low viability of the larval, pupal, and egg stages, causing adult deformation and a reduction of the number of eggs per female. PI 229358 prolonged the immature stage and reduced pupal weight, egg viability, and adult longevity. Considering all tests, 'IAC 17' and 'IAC 24' were characterized as having antibiosis-type resistance, and 'IAC PL-1' demonstrated to be a genotype suitable for insect development.O conhecimento do tipo de resistência presente em genótipos pode dinamizar programas de melhoramento que tenham essa finalidade. Assim, estudaram-se aspectos biológicos de Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae em folhas de quatro genótipos de soja, sendo três com diferentes níveis de resistência e um suscetível a insetos. Avaliaram-se os cultivares IAC 17 e IAC 24, portadores de resistência a desfolhadores e sugadores, a linhagem PI 229358, progenitora de diversas linhagens resistentes a A. gemmatalis, e

  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. 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

  13. Aspectos biológicos de Dione juno juno (Cramer (Lepidoptera: Nymphalidae em genótipos de maracujazeiro Biological aspects of Dione juno juno (Cramer (Lepidoptera: Nymphalidae on passion fruit genotypes

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    Arlindo Leal Boiça Júnior

    2008-03-01

    . edulis f. flavicarpa Deg. ('Sul Brasil', P. edulis f. flavicarpa, P. edulis f. flavicarpa ('Maguary FB-100' and P. foetida L. Fifty larvae from eggs collected in the field were used per genotype. Larvae were kept on passion fruits branches inside PVC tubes until pupation. Daily observations were performed and branches were replaced whenever necessary. The following parameters were evaluated: duration and viability of larval and pupal phases, larval and pupal weight and adult longevity. The experiment was arranged in randomized blocks design with seven treatments and ten replications. Data were subjected to an ANOVA and means were compared by Tukey test at 5% of probability. The least adequate genotypes for D. juno juno development were P. alata , P. serrato-digitata and P. foetida, showing a high level of antibiosis, while P. edulis, P. edulis f. flavicarpa, 'Maguary FB-100' and 'Sul Brasil' were the most suitable.

  14. A Review on Biological Control of Fungal Plant Pathogens Using Microbial Antagonists

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    Mohammad Pessarakli

    2010-01-01

    Full Text Available The objective of this study was to review the published research works on biological control of fungal plant diseases during past 50 years. Fungal plant pathogens are among the most important factors that cause serious losses to agricultural products every year. Biological control of plant diseases including fungal pathogens has been considered a viable alternative method to chemical control. In plant pathology, the term biocontrol applies to the use of microbial antagonists to suppress diseases. Throughout their lifecycle, plants and pathogens interact with a wide variety of organisms. These interactions can significantly affect plant health in various ways. Different mode of actions of biocontrol-active microorganisms in controlling fungal plant diseases include hyperparasitism, predation, antibiosis, cross protection, competition for site and nutrient and induced resistance. Successful application of biological control strategies requires more knowledge-intensive management. Various methods for application of biocontrol agents include: application directly to the infection court at a high population level to swamp the pathogen, application at one place in which biocontrol microorganisms are applied at one place (each crop year but at lower populations which then multiply and spread to other plant parts and give protection against pathogens and one time or occasional application that maintain pathogen populations below threshold levels. Commercial use and application of biological disease control have been slow mainly due to their variable performances under different environmental conditions in the field. To overcome this problem and in order to take the biocontrol technology to the field and improve the commercialization of biocontrol, it is important to develop new formulations of biocontrol microorganisms with higher degree of stability and survival. Majority of biocontrol products are applied against seed borne and soil borne fungal

  15. Métodos de analise dos danos da lagarta da espiga¹, em médias de gerações envolvendo IAC Maya e Zapalote Chico Method for analysis of damage of the corn earworm heliothis zea in generation means from IAC Maya and Zapalote Chico

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    Jorge Alberto Marques Rezende

    1982-01-01

    utilizing the revised scale described by WIDSTROM (27. The data obtained was analised by two different ways. The grades were distributed at first in two different classes: grades 0 and 1 and grades > 2. The grades were afterwards distributed in the following two classes: grades 0 and grades > 1. The chi-square test was applied to verify which of the two types of classes adjusts better with their respective expected ratios. The results showed that when the grades were divided in the classes 0+1 and > 2 the data were more uniform within each treatment. The analysis of variance for each damage class separately, presented F values highly significant for the classes zero and zero plus one, whereas for the classes > 1 and > 2 the damage averages were very similar and the F values were not significant. The class zero plus one had F value higher and the coefficient of variation smaller than the class zero. The ZC 2451 corn compared to the variety IAC Maya XII, exibited good resistance to the corn earworm, under the field conditions of Campinas, State of São Paulo, Brazil. This resistance is of the type non preference and or antibiosis, because there was a higher percentage of ears of ZC 2451 free of earworm damage.

  16. 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

  17. Efeito do lodo de esgoto na indução de supressividade in vitro a Phytophthora nicotianae Effect of sewage sludge in vitro to suppress Phytophthora nicotianae

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    Carolina Leoni

    2003-01-01

    evaluated by two experimental factors: sewage sludge doses (0, 10, 20 and 40% w/w and inoculum level [0, 10 and 20 g infested wheat (Triticum aestivum seeds per kg of soil]. After maintaining the mixtures (soil – sewage sludge – inoculum at room temperature for 21 days, treatments with higher organic matter had lower P. nicotianae survival, pH of the mixture, and higher electric conductivity (EC. Correlations between pathogen survival and EC were negative and significant (P>0,05. In order to evaluate the chemical effects of the sewage sludge on P. nicotianae, water, H2SO4 2N e KOH 0,4N extracts were obtained from sand - sewage sludge (20% w/w mixtures and each one of them was added to culture medium. The H2SO4 2N extract significantly (P>0,05 inhibited colony growth. The biological effect of the sewage sludge was evaluated by isolating microbial antagonists and testing them against P. nicotianae by bioassay and plate techniques. The bioassay technique selected one fungus (isolate F9.1, identified as Aspergillus sp. and one actinomycete (isolate A12.1, not identified. The plate technique selected one Trichoderma sp. and two actinomycetes for their antibiosis to P. nicotianae, and one Trichoderma sp. and three Aspergillus sp. for their hyper-parasitism to the pathogen.

  18. 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.

  19. Biology of Bemisia tabaci (Genn. B biotype (Hemiptera, Aleyrodidae on tomato genotypes Biologia de Bemisia tabaci (Genn. Biótipo B (Hemiptera, Aleyrodidae em genótipos de tomateiro

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    Maria Auxiliadora de Godoy Oriani

    2011-02-01

    Full Text Available Brazil is one of the main tomato (Solanum lycopersicum producers worldwide. Nevertheless, considerable part of the production is lost due to Bemisia tabaci (Genn. B biotype attacks. Resistant plants can be an important method for controlling this pest in an integrated pest management. Tests for evaluating some biological aspects of B. tabaci were carried out on 18 tomato genotypes, in controlled laboratory greenhouse conditions. Thirty-day-old plants placed in plastic cages were infested with 20 whitefly pairs each, for 24 h. The development of at least 30 eggs in three leaflets per plant (repetition was observed until adult emergence. The development period of insects grown in LA1335, PI365928 and LA722 genotypes took three days longer when compared to the ones grown in PI134418 (20.3 days. The highest mortality rate of whitefly nymphs occurred in PI365928, LA1335 and LA722 genotypes (63.8, 54.5 and 53.3%, respectively, and the smallest ones in IAC294 and IAC68F-22-2 genotypes (4.9 e 6.2%, respectively. LA1335, PI365928 and LA722 genotypes presented moderate feeding nonpreference and/or antibiosis-based resistance to B. tabaci B biotype.O Brasil é um dos maiores produtores mundiais de tomate (Solanum lycopersicum, porém grande parte da produção é perdida devido ao ataque de Bemisia tabaci (Genn. biótipo B. Entre as táticas de controle dessa praga num manejo integrado de pragas, pode-se relacionar a resistência de plantas. Ensaios para avaliar alguns aspectos biológicos de B. tabaci foram realizados com 18 genótipos de tomateiro, em condições controladas de laboratório (casa de vegetação. Plantas com 30 dias de idade foram colocadas em gaiolas plásticas e infestadas com 20 casais de moscas-brancas cada, durante 24h. Acompanhou-se então o desenvolvimento de pelo menos 30 ovos em três folíolos por planta (repetição até a emergência dos insetos. Os insetos criados nos genótipos LA1335, PI365928 e LA722 apresentaram

  20. 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