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Sample records for antibiosis

  1. Wild Solanum resistance to aphids: antixenosis or antibiosis?

    Science.gov (United States)

    Le Roux, Vincent; Dugravot, Sébastien; Campan, Erick; Dubois, Françoise; Vincent, Charles; Giordanengo, Philippe

    2008-04-01

    The type (antixenosis or antibiosis) of resistance against the aphids Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) was characterized for the wild tuber-bearing potatoes, Solanum chomatophilum Bitter and Solanum stoloniferum Schltdl. & Bouché through behavioral (olfactometry and electrical penetration graph) and physiological studies. In dual-choice assays, only S. stoloniferum exerted attraction to M. euphorbiae. This ruled out the possibility that plant volatiles of S. chomatophilum and S. stoloniferum may contribute to the high resistance expressed. In electrical penetration graph experiments, aphids feeding on S. stoloniferum showed increased salivation phases, whereas phloem ingestion was drastically reduced for both aphid species. Because reaching phloem elements was not delayed in both species, the resistance mechanism was phloem-located. The antixenosis exhibited by S. stoloniferum was similar on young and mature leaves. S. chomatophilum also showed phloem-located antixenosis against M. persicae. In contrast, M. euphorbiae had no difficulty to reach S. chomatophilum phloem tissues and to ingest sap. S. chomatophilum resistance against M. euphorbiae was antibiosis and only expressed in mature leaves, where a complete nymphal mortality was observed.

  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. 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.

  4. 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

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

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

    DEFF Research Database (Denmark)

    Nazaret, Sylvie; Aminov, Rustam

    2014-01-01

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

  7. Antibiosis of tomato, Solanum lycopersicum (Solanaceae plants to the Asopinae predator Supputius cincticeps (Heteroptera: Pentatomidae

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    AA de Castro

    2015-07-01

    Full Text Available , , , Plant feeding can improve development and reproduction of the stink bug Supputius cincticeps (Heteroptera: Pentatomidae, an important biological control agent in South American agro-forestry ecosystems. However, defensive compounds of plants may negatively impact this predator. The development, reproduction and survival of S. cincticeps fed on mealworm, Tenebrio molitor (Coleoptera: Tenebrionidae pupae with bean (Fabaceae, cotton (Malvaceae, eucalyptus (Myrtaceae, soybean (Fabaceae, or tomato (Solanaceae leaves were evaluated. Females and males were heavier and the number of nymphs produced per female, the oviposition period and the longevity of females of this predator were higher when fed on eucalyptus, soybean, bean, and cotton than with tomato leaves. Leaves of those plants improved biological parameters of S. cincticeps, while tomato leaves showed antibiosis with lower reproduction and survival of S. cincticeps, probably due to toxic compounds.

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

    Science.gov (United States)

    Coleson, Jenifer L; Miller, Ross H

    2005-06-01

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

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

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    José Luis Hernández Mendoza

    2015-12-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  11. 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

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    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

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

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    A. Nakhjavani F.

    2008-12-01

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

  13. An Interspecies Signaling System Mediated by Fusaric Acid Has Parallel Effects on Antifungal Metabolite Production by Pseudomonas protegens Strain Pf-5 and Antibiosis of Fusarium spp.

    Science.gov (United States)

    Quecine, Maria Carolina; Kidarsa, Teresa A; Goebel, Neal C; Shaffer, Brenda T; Henkels, Marcella D; Zabriskie, T Mark; Loper, Joyce E

    2015-12-11

    Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that suppresses soilborne plant diseases and produces at least seven different secondary metabolites with antifungal properties. We derived mutants of Pf-5 with single and multiple mutations in biosynthesis genes for seven antifungal metabolites: 2,4-diacetylphoroglucinol (DAPG), pyrrolnitrin, pyoluteorin, hydrogen cyanide, rhizoxin, orfamide A, and toxoflavin. These mutants were tested for inhibition of the pathogens Fusarium verticillioides and Fusarium oxysporum f. sp. pisi. Rhizoxin, pyrrolnitrin, and DAPG were found to be primarily responsible for fungal antagonism by Pf-5. Previously, other workers showed that the mycotoxin fusaric acid, which is produced by many Fusarium species, including F. verticillioides, inhibited the production of DAPG by Pseudomonas spp. In this study, amendment of culture media with fusaric acid decreased DAPG production, increased pyoluteorin production, and had no consistent influence on pyrrolnitrin or orfamide A production by Pf-5. Fusaric acid also altered the transcription of biosynthetic genes, indicating that the mycotoxin influenced antibiotic production by Pf-5 at the transcriptional level. Addition of fusaric acid to the culture medium reduced antibiosis of F. verticillioides by Pf-5 and derivative strains that produce DAPG but had no effect on antibiosis by Pf-5 derivatives that suppressed F. verticillioides due to pyrrolnitrin or rhizoxin production. Our results demonstrated the importance of three compounds, rhizoxin, pyrrolnitrin, and DAPG, in suppression of Fusarium spp. by Pf-5 and confirmed that an interspecies signaling system mediated by fusaric acid had parallel effects on antifungal metabolite production and antibiosis by the bacterial biological control organism.

  14. Folliculitis et perifolliculitis capitis abscedens et suffodiens controlled with a combination therapy: systemic antibiosis (metronidazole plus clindamycin), dermatosurgical approach, and high-dose isotretinoin.

    Science.gov (United States)

    Tchernev, Georgi

    2011-05-01

    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.

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

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    Georgi Tchernev

    2011-01-01

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

  16. 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

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    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.

  17. 红花紫荆叶总黄酮提取工艺及其抑菌和抗氧化活性%Extraction, Antibiosis and Antioxidant Activity Analysis of Total Flavonoids from Bauhinia blakeana Dunn Leaves

    Institute of Scientific and Technical Information of China (English)

    黄素华; 林标声; 江龙

    2016-01-01

    研究了超声波提取红花紫荆(Bauhinia blakeana Dunn)叶黄酮的条件及其抗菌、抗氧化的性能.结果表明,经过正交试验分析,总黄酮最佳提取工艺为乙醇体积分数60%,超声时间45 min,超声温度70℃,料液比1:20(m:V),该条件下总黄酮提取率为4.11%.红花紫荆叶总黄酮对大肠杆菌、金黄色葡萄球菌、白色念珠菌均有抑菌效果,对金黄色葡萄球菌的抑菌效果最好,对青霉的抑菌效果不明显;红花紫荆叶总黄酮对金黄色葡萄球菌和大肠杆菌最小抑菌溶度为0.025 g/mL,对白色念珠菌最小抑菌浓度为0.05 g/mL,对青霉最小抑菌浓度为0.6 g/mL.红花紫荆叶总黄酮对羟自由基、超氧阴离子自由基、亚硝酸盐均具有一定的清除作用,在浓度0.5~2.5 mg/mL的范围内,清除能力随着浓度的增加而增强,且强于阳性对照维生素C的清除能力,抗氧化能力较强.%The conditions of ultrasonic extraction of Bauhinia blakeana Dunn leaf flavonoids and its antibiosis and antioxidant capabilities were studied. The results showed that the optimum extraction process of total flavonoids was ethanol concentration 60%,ultrasonic time of 45 min,ultrasonic temperature 70℃and solvent ratio 1:20(m:V ) by orthogonal experiment,under opti-mal conditions the extraction rate of 4.11%. The total flavonoids of Bauhinia blakeana Dunn leaf had antibacterial effect a-gainst E. coli,Staphylococcus aureus,Candida albicans,and its antibacterial effect of Staphylococcus aureus was best,the effect of Penicillium was not obvious. The minimum inhibitory concentrations for S. aureus,E. coli was 0.025 g/mL,the minimum in-hibitory concentration for C.albicans and Penicillium were 0.05 g/mL and 0.6 g/mL. The total flavonoids from Bauhinia blakeana Dunn leaves had certain scavenging ability on hydroxyl free radicals,superoxide anion free radicals and nitrite,and at the range of 0.5~2.5 mg/mL,the concentration increase,the scavenging capacity enhance

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

    Institute of Scientific and Technical Information of China (English)

    王宇婷; 易有金; 夏菠; 杨建奎; 曾静

    2013-01-01

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

  19. 菌株Tu 49 代谢产物的分离及抗菌素活性的初步研究%The Isolation of the Strain Tu49 and the Study on the Activity of Its Antibiosis

    Institute of Scientific and Technical Information of China (English)

    迪力夏提·托呼提; 阿不都克里木·热依木

    2001-01-01

    从吐鲁番葡萄沟、苏公塔、五道林、交角沟等郊区采集的52种土样中筛选到一株能产有抗菌素活性的好气菌Tu49,革兰氏阳性,类群为黄色类群。所产生的抗菌素,对不同的微生物有明显的抑制作用。最适生长温度为30℃~32℃,最适pH为6.8~7.5,气生菌丝和孢子丝为无色,基丝体为黄色,产黄色可溶性色素。%We isolated aerial strain Tu 49 from 52 samples of soil in 5 outskirts of Turpan city, its colony was golden and Gram positives(G+).The antibiosis from strain Tu49 inhibited different microorganisms, The optimum growth temperature was 30~32℃ and pH was 6.8~7.5;aerial hypha and spore hypha was colourless, my cellium was yellow. Which can produce soluble figment.

  20. Socially mediated induction and suppression of antibiosis during bacterial coexistence

    NARCIS (Netherlands)

    Abrudan, Monica I.; Smakman, Fokko; Grimbergen, Ard Jan; Westhoff, Sanne; Miller, Eric L.; van Wezel, Gilles P.; Rozen, Daniel E.

    2015-01-01

    Despite their importance for humans, there is little consensus on the function of antibiotics in nature for the bacteria that produce them. Classical explanations suggest that bacteria use antibiotics as weapons to kill or inhibit competitors, whereas a recent alternative hypothesis states that anti

  1. Antibiosis of the pith maize to Sesamia nonagrioides (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Ordás, B; Butrón, A; Soengas, P; Ordás, A; Malvar, R A

    2002-10-01

    Thirteen inbred lines of maize (Zea mays L.) with different levels of stem resistance to the stem borer Sesamia nonagrioides Lefevbre were evaluated in the field and the laboratory to determine the antibiotic resistance to this pest. Inbreds CM151, CO125, and EP39 had antibiotic pith as well as stem resistance, so the pith could play a role in stem resistance. Inbreds A509, F473, and PB130 did not have antibiotic pith but had stem resistance; therefore, other mechanisms could confer stem resistance. Finally, the inbred MS1334 had antibiotic pith and did not show stem resistance; thus, other factors could compensate the effect of the pith. Therefore, although pith antibiotic compound seems to play a role in the defense against S. nonagrioides attack, it is not the only possible mechanism of defense.

  2. Antibiosis of vineyard ecosystem fungi against food-borne microorganisms.

    Science.gov (United States)

    Cueva, Carolina; Moreno-Arribas, M Victoria; Bartolomé, Begoña; Salazar, Óscar; Vicente, M Francisca; Bills, Gerald F

    2011-12-01

    Fermentation extracts from fungi isolated from vineyard ecosystems were tested for antimicrobial activities against a set of test microorganisms, including five food-borne pathogens (Staphylococcus aureus EP167, Acinetobacter baumannii (clinically isolated), Pseudomonas aeruginosa PAO1, Escherichia coli O157:H7 (CECT 5947) and Candida albicans MY1055) and two probiotic bacteria (Lactobacillus plantarum LCH17 and Lactobacillus brevis LCH23). A total of 182 fungi was grown in eight different media, and the fermentation extracts were screened for antimicrobial activity. A total of 71 fungi produced extracts active against at least one pathogenic microorganism, but not against any probiotic bacteria. The Gram-positive bacterium S. aureus EP167 was more susceptible to antimicrobial fungi broth extracts than Gram-negative bacteria and pathogenic fungi. Identification of active fungi based on internal transcribed spacer rRNA sequence analysis revealed that species in the orders Pleosporales, Hypocreales and Xylariales dominated. Differences in antimicrobial selectivity were observed among isolates from the same species. Some compounds present in the active extracts were tentatively identified by liquid chromatography-mass spectrometry. Antimicrobial metabolites produced by vineyard ecosystem fungi may potentially limit colonization and spoilage of food products by food-borne pathogens, with minimal effect on probiotic bacteria.

  3. Identification and Antibiosis of a Novel Actinomycete Strain RAF-11 Isolated From Iraqi Soil.

    Directory of Open Access Journals (Sweden)

    Rabah Forar Laidi

    2013-04-01

    Full Text Available A total of 35 actinomycetes strains were isolated from and around Baghdad, Iraq, at a depth of 5-10 m, by serial dilution agar plating method. Nineteen out of them showed noticeable antimicrobial activities against at least, to one of the target pathogens. Five among the nineteen were active against both Gram positive and Gram negative bacteria, yeasts and moulds. The most active isolate, strain RAF-11, based on its largest zone of inhibition and strong antifungal activity, especially against Candida albicans and Aspergillus niger, the causative of candidiasis and aspergillosis respectively, was selected for identification. Morphological and chemical studies indicated that this isolate belongs to the genus Streptomyces. Analysis of the 16S rDNA sequence showed a high similarity, 98 %, with the most closely related species, Streptomyces labedae NBRC 15864T/AB184704, S. erythrogriseus LMG 19406T/AJ781328, S. griseoincarnatus LMG 19316T/AJ781321 and S. variabilis NBRC 12825T/AB184884, having the closest match. From the taxonomic features, strain RAF-11 matched with S. labedae, in the morphological, physiological and biochemical characters, however it showed significant differences in morphological characteristics with this nearest species, S. labedae, which encourage us to consider our starin as a novel isolate and was given the suggested name, Streptomyces labedae strain RAF-11. ISP-4 broth medium supplemented with glucose and soybean powder at concentrations of 1g % and 0.1g % as carbon and nitrogen sources respectively, for 120h incubation at 28 °C, increased the active compounds production, where we recorded a strong activity against yeasts, 42mm inhibition zone against Candida albicans, 41mm against C. pseudotropicalis, 40mm against C. tropicalis, followed by 38mm against Rhodotorula minota and Aspergillus niger then, 35mm against both Aspergillus flavus and Bacillus subtilis. N-butanol was best solvent for antibiotic extraction compared to the other tried solvents.

  4. Antibiosis among selected paspalum taxa to the fall armyworm (Lepidoptera: Noctuidae)

    Science.gov (United States)

    Twenty six accessions of the warm-season perennial grass, Paspalum spp., were evaluated for response to the fall armyworm Spodoptera frugiperda (J. E. Smith), an important pest of turfgrass. In growth chamber, excised clipping studies, P. vaginatum 03-539-31 and P. vaginatum 03-525-22 were the most ...

  5. Differential antibiosis against Helicoverpa armigera exerted by distinct inhibitory repeat domains of Capsicum annuum proteinase inhibitors.

    Science.gov (United States)

    Joshi, Rakesh S; Gupta, Vidya S; Giri, Ashok P

    2014-05-01

    Plant defensive serine proteinase inhibitors (PIs) are known to have negative impact on digestive physiology of herbivore insects and thus have a crucial role in plant protection. Here, we have assessed the efficacy and specificity of three previously characterized inhibitory repeat domain (IRD) variants from Capsicum annuum PIs viz., IRD-7, -9 and -12 against gut proteinases from Helicoverpa armigera. Comparative study of in silico binding energy revealed that IRD-9 possesses higher affinity towards H. armigera serine proteinases as compared to IRD-7 and -12. H. armigera fed on artificial diet containing 5 TIU/g of recombinant IRD proteins exhibited differential effects on larval growth, survival rate and other nutritional parameters. Major digestive gut trypsin and chymotrypsin genes were down regulated in the IRD fed larvae, while few of them were up-regulated, this indicate alterations in insect digestive physiology. The results corroborated with proteinase activity assays and zymography. These findings suggest that the sequence variations among PIs reflect in their efficacy against proteinases in vitro and in vivo, which also could be used for developing tailor-made multi-domain inhibitor gene(s).

  6. Antibiosis plays a role in the context of direct interaction during antagonism of Paenibacillus polymyxa towards Fusarium oxysporum

    NARCIS (Netherlands)

    Dijksterhuis, J; Sanders, M; Gorris, L G; Smid, E J

    1999-01-01

    Interaction of Fusarium oxysporum and Paenibacillus polymyxa starts with polar attachment of bacteria to the fungal hyphae followed by the formation of a large cluster of non-motile cells embedded in an extracellular matrix in which the bacteria develop endospores. Enumeration of fungal viable count

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

    OpenAIRE

    Georgi Tchernev

    2011-01-01

    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 f...

  8. 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...

  9. Evaluation of Rice Germplasm for Resistance to the Small Brown Planthopper(Laodelphax striatellus)and Analysis of Resistance Mechanism

    Institute of Scientific and Technical Information of China (English)

    DUAN Can-xing; ZHANG Shi-xian; LEI Cai-lin; CHENG Zhi-jun; CHEN Qing; ZHAI Hu-qu; WAN Jian-min

    2008-01-01

    One hundred and thirty-eight rice accessions were screened for resistance to the small brown planthopper(SBPH)resistance to SBPH were detected,accounting for 18.1%of the total accessions,which included 2 highly resistant,9 resistant and 14 moderately resistant varieties.Compared with indica rice,japonica rice was more susceptible to SBPH.Antixenosis test,antibiosis test and correlation analysis were performed to elucidate the resistance mechanism.The resistant check Rathu Heenati(RHT),highly resistant varieties Mudgo and Kasalath,and resistant variety IR36 expressed strong antixenosis and antibiosis against SBPH,indicating the close relationship between resistance level and these two resistance mechanisms in the four rice varieties.Antibiosis was the dominant resistance pattern in the resistant varieties Daorenqiao and Yangmaogu due to their high antibiosis but low antixenosis.Dular,ASD7 and Milyang 23 had relatively strong antixenosis and antibiosis,indicating the two resistance mechanisms were significant in these three varieties.The resistant DV85 expressed relatively high level of antixenosis but low antibiosis,whereas Zhaiyeqing 8 and Guiyigu conferred only moderate antibiosis and antixenosis to SBPH,suggesting tolerance in these three varieties.Antibiosis and antixenosis governed the resistance to SBPH in the moderately resistant accession 9311.Antixenosis was the main resistance type in V20A.Tolerance was considered to be an important resistance mechanism in Minghui 63 and Yangjing 9538 due to their poor antibiosis and antixenosis resistance.The above accessions with strong antibiosis or antixenosis were the ideal materials for the resistance breeding.

  10. 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.)

  11. 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.

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

    Science.gov (United States)

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

    2015-01-29

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

  13. 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...

  14. 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.

  15. Induced systemic resistance by fluorescent Pseudomonas spp.

    NARCIS (Netherlands)

    Bakker, P.A.H.M.; Pieterse, C.M.J.; Loon, L.C. van

    2007-01-01

    Fluorescent Pseudomonas spp. have been studied for decades for their plant growth-promoting effects through effective suppression of soilborne plant diseases. The modes of action that play a role in disease suppression by these bacteria include siderophore-mediated competition for iron, antibiosis,

  16. Characterization of bacterial isolates from rotting potato tuber tissue showing antagonism to Dickeya sp. biovar 3 in vitro and in planta

    NARCIS (Netherlands)

    Czajkowski, R.L.; De Boer, W.J.; Van Veen, J.A.; Van der Wolf, J.M.

    2012-01-01

    Possibilities for biocontrol of biovar 3 Dickeya sp. in potato were investigated, using bacteria from rotting potato tissue isolated by dilution plating on nonselective agar media. In a plate assay, 649 isolates were screened for antibiosis against Dickeya sp. IPO2222 and for the production of sider

  17. Antibacterial enzymes from the functional screening of metagenomic libraries hosted in Ralstonia metallidurans.

    Science.gov (United States)

    Iqbal, Hala A; Craig, Jeffrey W; Brady, Sean F

    2014-05-01

    Phenotype-based screening of bacterial metagenomic libraries provides an avenue for the discovery of novel genes, enzymes, and metabolites that have a variety of potential clinical and industrial uses. Here, we report the identification of a functionally diverse collection of antibacterially active enzymes from the phenotypic screening of 700 000 cosmid clones prepared from Arizona soil DNA and hosted in Ralstonia metallidurans. Environmental DNA clones surrounded by zones of growth inhibition in a bacterial overlay assay were found, through bioinformatics and functional analyses, to encode enzymes with predicted peptidase, lipase, and glycolytic activities conferring antibiosis. The antibacterial activities observed in our R. metallidurans-based assay could not be replicated with the same clones in screens using Escherichia coli as a heterologous host, suggesting that the large-scale screening of metagenomic libraries for antibiosis using phylogenetically diverse hosts should be a productive strategy for identifying enzymes with functionally diverse antibacterial activities.

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

    Directory of Open Access Journals (Sweden)

    Kunihiko Komatsu

    2007-01-01

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

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    Xiang-Shun Hu

    Full Text Available 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

  1. Induced Systemic Resistance and the Rhizosphere Microbiome

    OpenAIRE

    Bakker, Peter A. H. M.; Doornbos, Rogier F.; Christos Zamioudis; 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...

  2. Search for endophytic diazotrophs in barley seeds.

    Science.gov (United States)

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

    2014-01-01

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

  3. 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)

  4. Antagonism of Bacillus spp. against Xanthomonas campestris pv. campestris

    OpenAIRE

    Leila Monteiro; Rosa de Lima Ramos Mariano; Ana Maria Souto-Maior

    2005-01-01

    The antagonism of eight Bacillus isolates was investigated against nine strains of Xanthomonas campestris pv. campestris (causal agent of crucifers black rot) to assess the role of lipopeptides in this process. Antimicrobial and hemolytic (surfactant) activity tests were performed in vitro using agar diffusion methods. Antibiosis and hemolysis were positive for four Bacillus isolates against all X. campestris pv. campestris strains. The correlation observed between antimicrobial and hemolytic...

  5. Numerical studies of biocontrol efficacies of foliar plant pathogens in relation to the characteristics of a biocontrol agent.

    Science.gov (United States)

    Xu, X-M; Salama, N; Jeffries, P; Jeger, M J

    2010-08-01

    A previously published generic mathematic model has been used in a numerical study to understand the dynamics of foliar pathogens in relation to mechanisms, and timing and coverage of biocontrol agent (BCA) applications. With the model parameter values used, it was demonstrated that a BCA possessing either competition or induced resistance as the main mechanism of biological control was more effective in reducing disease development than a BCA with either mycoparasitism or antibiosis as its mechanism. Application coverage, ranging from 50 to 90%, had little effect on biocontrol efficacy, particularly for a BCA with competition and induced resistance as the main mechanism of biocontrol. Conversely, delayed application of BCA had more profound effects on biocontrol efficacy for those with competition or induced resistance as their main mechanism than those with mycoparasitism and antibiosis. Biocontrol efficacy was greatest for a single BCA combining competition with mycoparasitism or antibiosis. The efficacy for a single BCA combining induced resistance with competition critically depended on application time; the efficacy was greatly reduced for delayed applications. The present study suggests that development of an effective strategy for BCA application is critically dependent upon our quantitative understanding of several key biocontrol processes and their interactions. Without reliable quantitative estimation of these processes, it is impossible to make quantitative predictions about biological control and hence to optimize BCA application strategies.

  6. 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)

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

    Science.gov (United States)

    Kawaguchi, Akira

    2014-09-17

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

  8. Inhibición de Fusarium oxysporum por cepas mutantes de Pseudomonas fluorescens Zum80 incapaces de producir sideróforos

    OpenAIRE

    Eduardo Valencia-Cantero; Javier Villegas-Moreno; Juan Manuel Sánchez-Yáñez; Juan José Peña-Cabriales; Rodolfo Farías-Rodríguez

    2005-01-01

    Pseudomonas fluorescens, cepa ZUM80, es una bacteria productora de sideróforos que inhibe el crecimiento de microorganismos fitopatógenos en condiciones de escasez de hierro. Con el fin de entender el mecanismo de inhibición de la cepa ZUM80 sobre Fusarium oxysporum, se obtuvieron mutantes incapaces de sintetizar sideróforos, por medio de la exposición de P. fluorescens ZUM80 a nitrosoguanidina. Ensayos de antibiosis en condiciones de escasez de hierro, mostraron que, cuando se inoculó el hon...

  9. Resistencia bacteriana a los antibióticos

    OpenAIRE

    Crispín Pérez, Victor

    2014-01-01

    El descubrimiento de la antibiosis "in vitro" y el desarrollo de los antibióticos generó la ilusión del control de las enfermedades infecciosas bacterianas. Sin embargo, tan pronto como estas moléculas maravillosas fuero introducidas en la clínica, casi de inmediato surgieron las cepas bacterianas con resistencia adquirida, como se ha comprobado en las colecciones de cepas aisladas en las décadas del 50 del siglo pasado. Las moléculas de antibióticos inhiben o matan a las cepas sensibles, inh...

  10. Complications of the diabetic foot.

    Science.gov (United States)

    Kim, Paul J; Steinberg, John S

    2013-12-01

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

  11. 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.

  12. Suitability of Soybean Meal from Insect-Resistant Soybeans for Broiler Chickens.

    Science.gov (United States)

    Ortega, María A; Davis, Adam J; Boerma, H Roger; Parrott, Wayne A

    2016-03-23

    Benning(M) and Benning(MGH) are near-isogenic lines (NILs) of the soybean cultivar Benning, which contain insect-resistance quantitative trait loci (QTLs) from the soybean accession PI 229358. Benning(M) contains QTL-M, which confers antibiosis and antixenosis. In addition to QTL-M, Benning(MGH) contains QTL-G, which confers antibiosis, and QTL-H, which confers antixenosis. Soybean meal was produced from Benning and the NILs. Nutritional composition, digestible amino acid content, and nitrogen-corrected true metabolizable energy (TMEN) were equivalent among soybean meals. A 21-day broiler feeding trial was carried out to determine if the QTLs affect soybean meal quality. Weight gain and feed-to-gain ratio were evaluated. No biologically significant differences were detected for broilers fed Benning, Benning(M), and Benning(MGH). This demonstrates that soybean meal produced from the insect-resistant NILs is equivalent to soybean meal produced from their non-insect-resistant parent cultivar for broiler weight gain.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Identification of Soybean Resources of Resistance to Aphids

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  2. Ziyuglycoside II-induced apoptosis in human gastric carcinoma BGC-823 cells by regulating Bax/Bcl-2 expression and activating caspase-3 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, A.K. [Department of General Surgery, Nanjing Medical University, Affiliated Hangzhou Hospital, Hangzhou (China); Zhou, H.; Xia, J.Z. [Department of General Surgery, Nanjing Medical University, Affiliated Wuxi Second Hospital, Wuxi (China); Jin, H.C. [Department of General Surgery, Nanjing Medical University, Affiliated Hangzhou Hospital, Hangzhou (China); Wang, K. [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu Province (China); Yan, J.; Zuo, J.B. [Department of General Surgery, Nanjing Medical University, Affiliated Wuxi Second Hospital, Wuxi (China); Zhu, X. [Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu Province (China); Shan, T. [Department of General Surgery, Nanjing Medical University, Affiliated Wuxi Second Hospital, Wuxi (China)

    2013-08-13

    Ziyuglycoside II is an active compound of Sanguisorba officinalis L. that has anti-inflammation, antioxidation, antibiosis, and homeostasis properties. We report here on the anticancer effect of ziyuglycoside II on human gastric carcinoma BGC-823 cells. We investigated the effects of ziyuglycoside II on cell growth, cell cycle, and cell apoptosis of this cell line. Our results revealed that ziyuglycoside II could inhibit the proliferation of BGC-823 cells by inducing apoptosis but not cell cycle arrest, which was associated with regulation of Bax/Bcl-2 expression, and activation of the caspase-3 pathway. Our study is the first to report the antitumor potential of ziyuglycoside II in BGC-823 gastric cancer cells. Ziyuglycoside II may become a potential therapeutic agent against gastric cancer in the future.

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

    Directory of Open Access Journals (Sweden)

    Francisco de A.G. da Silva

    1998-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Piedad M. Montero Castillo

    2015-06-01

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

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

    Science.gov (United States)

    Wollina, Uwe; Graf, Andreas; Hanisch, Volkmar

    2015-05-01

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

  6. 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.

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

    Science.gov (United States)

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

    2016-02-01

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

  8. Characterization of cowpea genotype resistance to Callosobruchus maculatus

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Živković Svetlana

    2010-01-01

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

  10. A numerical study of combined use of two biocontrol agents with different biocontrol mechanisms in controlling foliar pathogens.

    Science.gov (United States)

    Xu, X-M; Jeffries, P; Pautasso, M; Jeger, M J

    2011-09-01

    Effective use of biocontrol agents is an important component of sustainable agriculture. A previous numerical study of a generic model showed that biocontrol efficacy was greatest for a single biocontrol agent (BCA) combining competition with mycoparasitism or antibiosis. This study uses the same mathematical model to investigate whether the biocontrol efficacy of combined use of two BCAs with different biocontrol mechanisms is greater than that of a single BCA with either or both of the two mechanisms, assuming that two BCAs occupy the same host tissue as the pathogen. Within the parameter values considered, a BCA with two biocontrol mechanisms always outperformed the combined use of two BCAs with a single but different biocontrol mechanism. Similarly, combined use of two BCAs with a single but different biocontrol mechanism is shown to be far less effective than that of a single BCA with both mechanisms. Disease suppression from combined use of two BCAs was very similar to that achieved by the more efficacious one. As expected, a higher BCA introduction rate led to increased disease suppression. Incorporation of interactions between two BCAs did not greatly affect the disease dynamics except when a mycoparasitic and, to a lesser extent, an antibiotic-producing BCA was involved. Increasing the competitiveness of a mycoparasitic BCA over a BCA whose biocontrol mechanism is either competition or antibiosis may lead to improved biocontrol initially and reduced fluctuations in disease dynamics. The present study suggests that, under the model assumptions, combined use of two BCAs with different biocontrol mechanisms in most cases only results in control efficacies similar to using the more efficacious one alone. These predictions are consistent with published experimental results, suggesting that combined use of BCAs should not be recommended without clear understanding of their main biocontrol mechanisms and relative competitiveness, and experimental evaluation.

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

    Directory of Open Access Journals (Sweden)

    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

  12. Aislamiento de microorganismos para control biológico de Moniliophthora roreri

    Directory of Open Access Journals (Sweden)

    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%.

  13. 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.

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

    Science.gov (United States)

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

    2016-03-07

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

  15. Antagonism of Bacillus spp. against Xanthomonas campestris pv. campestris

    Directory of Open Access Journals (Sweden)

    Leila Monteiro

    2005-01-01

    Full Text Available The antagonism of eight Bacillus isolates was investigated against nine strains of Xanthomonas campestris pv. campestris (causal agent of crucifers black rot to assess the role of lipopeptides in this process. Antimicrobial and hemolytic (surfactant activity tests were performed in vitro using agar diffusion methods. Antibiosis and hemolysis were positive for four Bacillus isolates against all X. campestris pv. campestris strains. The correlation observed between antimicrobial and hemolytic activities indicated that lipopeptides were involved in the antibiosis mechanism of the studied antagonists. Fermentation studies were carried out with the isolates that showed highest antimicrobial and hemolytic activities, to follow up growth and production of bioactive and surfactant compounds. Production of bioactive and surfactant compounds was observed during the late growth phase of the Bacillus isolates.Investigação sobre o antagonismo de oito isolados de Bacillus: B. subtilis R14, B. megaterium pv. cerealis RAB7, B. megaterium pv. cerealis C211, B. megaterium C116, Bacillus sp. RAB9, B. cereus C240, Bacillus sp. C11 e B. cereus C210, contra nove linhagens de X. campestris pv. campestris (bactéria responsável pela podridão negra das crucíferas foi realizada para se verificar a participação de lipopeptídeos neste mecanismo. Testes de atividades antimicrobiana e hemolítica (surfactante foram realizados, utilizando-se o método de difusão em ágar. Antibiose e hemólise foram positivas para quatro isolados de Bacillus: R14, RAB7, C116 e C210. A correlação observada entre as atividades antimicrobiana e a hemolítica indica que lipopeptídeos estão envolvidos no mecanismo de antibiose dos isolados investigados. As fermentações foram realizadas com os isolados que demonstraram melhores resultados nos testes de atividades antimicrobiana e hemolítica: R14, RAB7 e C116, para acompanhar o crescimento e a produção de compostos bioativos e

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    Ruth Noemí Águila-Ramírez

    2012-04-01

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

  18. 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.

  19. miRNA-mediated auxin signalling repression during Vat-mediated aphid resistance in Cucumis melo.

    Science.gov (United States)

    Sattar, Sampurna; Addo-Quaye, Charles; Thompson, Gary A

    2016-06-01

    Resistance to Aphis gossypii in melon is attributed to the presence of the single dominant R gene virus aphid transmission (Vat), which is biologically expressed as antibiosis, antixenosis and tolerance. However, the mechanism of resistance is poorly understood at the molecular level. Aphid-induced transcriptional changes, including differentially expressed miRNA profiles that correspond to resistance interaction have been reported in melon. The potential regulatory roles of miRNAs in Vat-mediated aphid resistance were further revealed by identifying the specific miRNA degradation targets. A total of 70 miRNA:target pairs, including 28 novel miRNA:target pairs, for the differentially expressed miRNAs were identified: 11 were associated with phytohormone regulation, including six miRNAs that potentially regulate auxin interactions. A model for a redundant regulatory system of miRNA-mediated auxin insensitivity is proposed that incorporates auxin perception, auxin modification and auxin-regulated transcription. Chemically inhibiting the transport inhibitor response-1 (TIR-1) auxin receptor in susceptible melon tissues provides in vivo support for the model of auxin-mediated impacts on A. gossypii resistance.

  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. 天然药物活性成分与溶菌酶相互作用的研究进展%Advance of studies on interaction between active components of natural medicines and lysozymes

    Institute of Scientific and Technical Information of China (English)

    陈晨; 张洪峰; 王乐; 黄芸; 魏亚超; 郭金明; 郭莹

    2012-01-01

    溶菌酶是一种广泛存在于生物体内的小分子碱性蛋白,具有抗菌消炎、抗病毒、增强免疫力等多种药理作用.能够和许多外源和内源性物质结合,运载多种药物.该文综述了不同种类的天然药物活性成分与溶菌酶的相互作用,对于全面认识天然药物的药理机制,了解药物在生物体内的转运和代谢过程以及优化药物分子结构、提高天然药物的生物利用率和生物效应等都具有重要的意义.%Lysozyme (LYSO) , as an alkalescent protein micromolecule in living organisms, exhibits important pharmacological actions such as antibiosis, anti-inflammatory, antivirus and enhancing immunity. LYSO can combine with many exogenous and endogenous substances and carry many drugs. This essay summarizes interaction between different kincis of active components of natural medicines and lysozymes, which is significant to comprehensively understand pharmacological mechanism of natural drugs and their transfer and metabolic process in organisms, optimize molecule structures of drugs and increase bioavailability and biological effects of natural drugs.

  2. 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

    2016-04-22

    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.

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

    Science.gov (United States)

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

    2012-04-01

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

  4. Contrasting microbial biogeographical patterns between anthropogenic subalpine grasslands and natural alpine grasslands.

    Science.gov (United States)

    Geremia, Roberto A; Pușcaș, Mihai; Zinger, Lucie; Bonneville, Jean-Marc; Choler, Philippe

    2016-02-01

    The effect of plant species composition on soil microbial communities was studied at the multiregional level. We compared the soil microbial communities of alpine natural grasslands dominated by Carex curvula and anthropogenic subalpine pastures dominated by Nardus stricta. We conducted paired sampling across the Carpathians and the Alps and used Illumina sequencing to reveal the molecular diversity of soil microbes. We found that bacterial and fungal communities exhibited contrasting regional distributions and that the distribution in each grassland is well discriminated. Beta diversity of microbial communities was much higher in C. curvula grasslands due to a marked regional effect. The composition of grassland-type core microbiomes suggest that C. curvula, and N. stricta to a lesser extent, tend to select a cohort of microbes related to antibiosis/exclusion, pathogenesis and endophytism. We discuss these findings in light of the postglacial history of the studied grasslands, the habitat connectivity and the disturbance regimes. Human-induced disturbance in the subalpine belt of European mountains has led to homogeneous soil microbial communities at large biogeographical scales. Our results confirm the overarching role of the dominant grassland plant species in the distribution of microbial communities and highlight the relevance of biogeographical history.

  5. 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.

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

    Institute of Scientific and Technical Information of China (English)

    于淑文; 丁樱

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    邓福明; 王挥; 赵松林; 陈卫军

    2013-01-01

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

  8. Ecological implications of anti-pathogen effects of tropical fungal endophytes and mycorrhizae.

    Science.gov (United States)

    Herre, Edward Allen; Mejía, Luis C; Kyllo, Damond A; Rojas, Enith; Maynard, Zuleyka; Butler, Andre; Van Bael, Sunshine A

    2007-03-01

    We discuss studies of foliar endophytic fungi (FEF) and arbuscular mycorrhizal fungi (AMF) associated with Theobroma cacao in Panama. Direct, experimentally controlled comparisons of endophyte free (E-) and endophyte containing (E+) plant tissues in T. cacao show that foliar endophytes (FEF) that commonly occur in healthy host leaves enhance host defenses against foliar damage due to the pathogen (Phytophthora palmivora). Similarly, root inoculations with commonly occurring AMF also reduce foliar damage due to the same pathogen. These results suggest that endophytic fungi can play a potentially important mutualistic role by augmenting host defensive responses against pathogens. There are two broad classes of potential mechanisms by which endophytes could contribute to host protection: (1) inducing or increasing the expression of intrinsic host defense mechanisms and (2) providing additional sources of defense, extrinsic to those of the host (e.g., endophyte-based chemical antibiosis). The degree to which either of these mechanisms predominates holds distinct consequences for the evolutionary ecology of host-endophyte-pathogen relationships. More generally, the growing recognition that plants are composed of a mosaic of plant and fungal tissues holds a series of implications for the study of plant defense, physiology, and genetics.

  9. 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.

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

    Science.gov (United States)

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

    2010-07-01

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

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

    Science.gov (United States)

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

    2011-08-01

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

  13. Compatibility study of Trichoderma harzianum Rifai and rice fungicides, and effects on three fungal plant pathogens

    Directory of Open Access Journals (Sweden)

    Manuel Francisco Rodríguez Saldaña

    2017-04-01

    Full Text Available This research took place at the Provincial Plant Sanitation Laboratory, in Camaguey, Cuba, between September 2013 and September 2015. The in vitro compatibility and antagonistic capacity of Trichoderma harzianum Rifai (strain A-34 on rice pathogens (Bipolaris oryzae Breda de Haan, Sarocladium oryzae (Sawada w., Gams and D. Hawksworth and Magnaporthe grisea (Hebert Barr, was determined against pesticides used on rice. Assessment using traditional methods of microbiological isolation of mycelial growth, sporulation and conidial germination of the antagonist, to determine if the action mechanisms (antibiosis, competence, parasitism against fungal pathogens, was made between 24 and 216 hours of application. A bifactorial design in dual culture was used for statistical analysis, along with scales for determination of microbial antagonistic capacity. Active ingredients tebuconazol + procloraz, trifloxistrobin+ ciproconazole, and epoxiconazole + kresoxim-methyl, affected mycelial growth of the antagonist. Moreover, the antagonist against active ingredients carbendazim, copper oxychloride, azoxystrobin and tebuconazo + triadimenol showed mycelial growth, sporulation and pathogen interaction, affecting their growth by means of coiling, penetration, granulation, and cell lysis, between 96 and 216 hours.

  14. 壳聚糖涂膜在动物性产品保藏方面的研究进展

    Institute of Scientific and Technical Information of China (English)

    韩剑花; 于有伟

    2013-01-01

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

  15. 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

    2016-01-01

    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.

  16. Bacterial identification in real samples by means of micro-Raman spectroscopy

    Science.gov (United States)

    Rösch, Petra; Stöckel, Stephan; Meisel, Susann; Bossecker, Anja; Münchberg, Ute; Kloss, Sandra; Schumacher, Wilm; Popp, Jürgen

    2011-07-01

    Pathogen detection is essential without time delay especially for severe diseases like sepsis. Here, the survival rate is dependent on a prompt antibiosis. For sepsis three hours after the onset of shock the survival rate of the patient drops below 60 %. Unfortunately, the results from standard diagnosis methods like PCR or microbiology can normally be received after 12 or 36 h, respectively. Therefore diagnosis methods which require less cultivation or even no cultivation at all have to be established for medical diagnosis. Here, Raman spectroscopy, as a vibrational spectroscopic method, is a very sensitive and selective approach and monitors the biochemical composition of the investigated sample. Applying micro-Raman spectroscopy allows for a spatial resolution below 1 μm and is therefore in the size range of bacteria. Raman spectra of bacteria depend on the physiological status. Therefore, the databases require the inclusion of the necessary environmental parameters such as temperature, pH, nutrition, etc. Such large databases therefore require a specialized chemometric approach, since the variation between different strains is small. In this contribution we will demonstrate the capability of Raman spectroscopy to identify pathogens without cultivation even from real environmental or medical samples.

  17. 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.

  18. Genetic basis of multiple resistance to the brown planthopper (Nilaparvata lugens Stål) and the green rice leafhopper (Nephotettix cincticeps Uhler) in the rice cultivar 'ASD7' (Oryza sativa L. ssp. indica).

    Science.gov (United States)

    Van Mai, Tan; Fujita, Daisuke; Matsumura, Masaya; Yoshimura, Atsushi; Yasui, Hideshi

    2015-12-01

    The rice cultivar ASD7 (Oryza sativa L. ssp. indica) is resistant to the brown planthopper (BPH; Nilaparvata lugens Stål) and the green leafhopper (Nephotettix virescens Distant). Here, we analyzed multiple genetic resistance to BPH and the green rice leafhopper (GRH; Nephotettix cincticeps Uhler). Using two independent F2 populations derived from a cross between ASD7 and Taichung 65 (Oryza sativa ssp. japonica), we detected two QTLs (qBPH6 and qBPH12) for resistance to BPH and one QTL (qGRH5) for resistance to GRH. Linkage analysis in BC2F3 populations revealed that qBPH12 controlled resistance to BPH and co-segregated with SSR markers RM28466 and RM7376 in plants homozygous for the ASD7 allele at qBPH6. Plants homozygous for the ASD7 alleles at both QTLs showed a much faster antibiosis response to BPH than plants homozygous at only one of these QTLs. It revealed that epistatic interaction between qBPH6 and qBPH12 is the basis of resistance to BPH in ASD7. In addition, qGRH5 controlled resistance to GRH and co-segregated with SSR markers RM6082 and RM3381. qGRH5 is identical to GRH1. Thus, we clarified the genetic basis of multiple resistance of ASD7 to BPH and GRH.

  19. Genetic basis of multiple resistance to the brown planthopper (Nilaparvata lugens Stål) and the green rice leafhopper (Nephotettix cincticeps Uhler) in the rice cultivar ‘ASD7’ (Oryza sativa L. ssp. indica)

    Science.gov (United States)

    Van Mai, Tan; Fujita, Daisuke; Matsumura, Masaya; Yoshimura, Atsushi; Yasui, Hideshi

    2015-01-01

    The rice cultivar ASD7 (Oryza sativa L. ssp. indica) is resistant to the brown planthopper (BPH; Nilaparvata lugens Stål) and the green leafhopper (Nephotettix virescens Distant). Here, we analyzed multiple genetic resistance to BPH and the green rice leafhopper (GRH; Nephotettix cincticeps Uhler). Using two independent F2 populations derived from a cross between ASD7 and Taichung 65 (Oryza sativa ssp. japonica), we detected two QTLs (qBPH6 and qBPH12) for resistance to BPH and one QTL (qGRH5) for resistance to GRH. Linkage analysis in BC2F3 populations revealed that qBPH12 controlled resistance to BPH and co-segregated with SSR markers RM28466 and RM7376 in plants homozygous for the ASD7 allele at qBPH6. Plants homozygous for the ASD7 alleles at both QTLs showed a much faster antibiosis response to BPH than plants homozygous at only one of these QTLs. It revealed that epistatic interaction between qBPH6 and qBPH12 is the basis of resistance to BPH in ASD7. In addition, qGRH5 controlled resistance to GRH and co-segregated with SSR markers RM6082 and RM3381. qGRH5 is identical to GRH1. Thus, we clarified the genetic basis of multiple resistance of ASD7 to BPH and GRH. PMID:26719745

  20. 2010年我国工程塑料应用进展%ADVANCE IN THE ENGINEERING PLASTICS APPLICATION OF CHINA IN 2010

    Institute of Scientific and Technical Information of China (English)

    闫烨; 杨超

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    徐先祥

    2012-01-01

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

  2. 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.

  3. Isolation and Screening of Antagonistic Bacteria to Setosphaeria turcica%玉米大斑病拮抗细菌的分离与筛选

    Institute of Scientific and Technical Information of China (English)

    刘洪亮; 王慧

    2012-01-01

    Totally 1182 bacterial strains were isolated from corn rhizosphere soils, of which 24 strains were antagonistic to Setosphaeria turcica. KD16-13 and KJ2-01 strains showed antibiosis activity to phytopathogenic fungi, such as Pyricularia grisea, Alternaria solani, Rhizoctonia solani, Fusarium oxysporum, Fusarium graminearum, Al-ternaria alternate, Fusarium wilt.%采用土壤稀释法从玉米根际土壤中分离得到1182株细菌菌株,从中筛选对玉米大斑病菌具有较强拮抗的菌株24个.对24株拮抗菌抗菌谱的测定结果表明,KD16-13 、KJ2-01对水稻稻瘟病菌、马铃薯早疫病菌、水稻纹枯病菌、尖孢镰刀菌、禾谷镰刀菌、链格孢菌、番茄枯萎病菌具有较强的拮抗作用且抑菌效果明显.

  4. 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:

  5. Puncture resistance in 'Sharwil' avocado to oriental fruit fly and Mediterranean fruit fly (Diptera: Tephritidae) oviposition.

    Science.gov (United States)

    Follett, Peter A

    2009-06-01

    The physiological basis for host antibiosis or nonpreference to a quarantine pest is often not understood. Studies are needed on the mechanisms that impart resistance to better understand how resistance might fail. Experiments were conducted to examine the infestability of 'Sharwil' avocados by oriental fruit fly, Bactrocera dorsalis (Hendel), and Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), after harvest and to quantify the effect of avocado skin hardness on resistance to infestation by oriental fruit fly. Infestation rate increased with decreasing fruit firmness, but fruit were generally poor hosts. Fruit with a patch of skin removed produced more flies than intact fruit, suggesting that skin puncture resistance was an important deterrent to oviposition. This study showed that fruit can be infested within 1 d after harvest, suggesting that fruit should be transferred to fruit fly-proof containers as they are harvested to minimize the risk of attack. Although risk of infestation is negatively correlated with fruit firmness, even some hard fruit may become infested. Therefore, fruit firmness cannot be used alone as an indicator to ensure fruit fly-free 'Sharwil' avocados. Measuring fruit firmness may be a useful component of a multiple component systems approach as an additional safeguard to reduce risk of infestation.

  6. 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.

  7. Bacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian contaminated systems.

    Science.gov (United States)

    Oyetibo, Ganiyu O; Ilori, Matthew O; Adebusoye, Sunday Adekunle; Obayori, Oluwafemi S; Amund, Olukayode O

    2010-09-01

    Samples of soil, water, and sediments from industrial estates in Lagos were collected and analyzed for heavy metals and physicochemical composition. Bacteria that are resistant to elevated concentrations of metals (Cd(2+), Co(2+), Ni(2+), Cr(6+), and Hg(2+)) were isolated from the samples, and they were further screened for antibiotic sensitivity. The minimum tolerance concentrations (MTCs) of the isolates with dual resistance to the metals were determined. The physicochemistry of all the samples indicated were heavily polluted. Twenty-two of the 270 bacterial strains isolated showed dual resistances to antibiotics and heavy metals. The MTCs of isolates to the metals were 14 mM for Cd(2+), 15 mM for Co(2+) and Ni(2+), 17 mM for Cr(6+), and 10 mM for Hg(2+). Five strains (Pseudomonas aeruginosa, Actinomyces turicensis, Acinetobacter junni, Nocardia sp., and Micrococcus sp.) resisted all the 18 antibiotics tested. Whereas Rhodococcus sp. and Micrococcus sp. resisted 15 mM Ni(2+), P. aeruginosa resisted 10 mM Co(2+). To our knowledge, there has not been any report of bacterial strains resisting such high doses of metals coupled with wide range of antibiotics. Therefore, dual expressions of antibiotics and heavy-metal resistance make the isolates, potential seeds for decommissioning of sites polluted with industrial effluents rich in heavy metals, since the bacteria will be able to withstand in situ antibiosis that may prevail in such ecosystems.

  8. 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.

  9. Sedum sarmentosum Bunge extract induces apoptosis and inhibits proliferation in pancreatic cancer cells via the hedgehog signaling pathway.

    Science.gov (United States)

    Bai, Yongheng; Chen, Bicheng; Hong, Weilong; Liang, Yong; Zhou, Mengtao; Zhou, Lan

    2016-05-01

    Sedum sarmentosum Bunge, a traditional Chinese herbal medicine, has a wide range of clinical applications including antibiosis, anti-inflammation and anti-oxidation. In the present study, we identified that its extract (SSBE) exerts pancreatic anticancer activity in vitro and in vivo. In the cultured pancreatic cancer PANC-1 cell line, SSBE inhibited cell growth in a concentration-dependent manner, and it was accompanied by the downregulated expression of proliferating cell nuclear antigen (PCNA). In addition, SSBE treatment also increased cellular apoptosis in a mitochondrial-dependent manner. Moreover, SSBE induced p53 expression, reduced c-Myc expression, and inhibited epithelial-mesenchymal transition (EMT). The antiproliferative activity of SSBE in the pancreatic cancer cells was found to be closely related to cell cycle arrest at the G2/M phase by upregulating p21(Waf1/CIP1) expression. Further study showed that this inhibitory effect of SSBE was through downregulation of the activity of the proliferation-related Hedgehog signaling pathway. Exogenous recombinant protein Shh was used to activate Hedgehog signaling, thereby resulting in the abolishment of the SSBE-mediated inhibition of pancreatic cancer cell growth. In animal xenograft models of pancreatic cancer, activated Hedgehog signaling was also observed compared with the vehicle controls, but was reduced by SSBE administration. As a result, SSBE suppressed the growth of pancreatic tumors. Thus, these findings demonstrate that SSBE has therapeutic potential for pancreatic cancer, and this anticancer effect in pancreatic cancer cells is associated with inhibition of the Hedgehog signaling pathway.

  10. 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.

  11. 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。

  12. 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)

  13. The iturin and fengycin families of lipopeptides are key factors in antagonism of Bacillus subtilis toward Podosphaera fusca.

    Science.gov (United States)

    Romero, Diego; de Vicente, Antonio; Rakotoaly, Rivo H; Dufour, Samuel E; Veening, Jan-Willem; Arrebola, Eva; Cazorla, Francisco M; Kuipers, Oscar P; Paquot, Michel; Pérez-García, Alejandro

    2007-04-01

    Podosphaera fusca is the main causal agent of cucurbit powdery mildew in Spain. Four Bacillus subtilis strains, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, with proven ability to suppress the disease on melon in detached leaf and seedling assays, were subjected to further analyses to elucidate the mode of action involved in their biocontrol performance. Cell-free supernatants showed antifungal activities very close to those previously reported for vegetative cells. Identification of three lipopeptide antibiotics, surfactin, fengycin, and iturin A or bacillomycin, in butanolic extracts from cell-free culture filtrates of these B. subtilis strains pointed out that antibiosis could be a major factor involved in their biocontrol ability. The strong inhibitory effect of purified lipopeptide fractions corresponding to bacillomycin, fengycin, and iturin A on P. fusca conidia germination, as well as the in situ detection of these lipopeptides in bacterial-treated melon leaves, provided interesting evidence of their putative involvement in the antagonistic activity. Those results were definitively supported by site-directed mutagenesis analysis, targeted to suppress the biosynthesis of the different lipopeptides. Taken together, our data have allowed us to conclude that the iturin and fengycin families of lipopeptides have a major role in the antagonism of B. subtilis toward P. fusca.

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

    Institute of Scientific and Technical Information of China (English)

    罗建军; 李辉; 耿鹏; 胡美英

    2012-01-01

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

  16. Combined Effect of Fermentation Filtrate of Pythium oligandrurn and Chemical Pesticide Against Tomato Phytophthora infestans%寡雄腐霉发酵液与化学农药联用对番茄晚疫病菌的防治作用

    Institute of Scientific and Technical Information of China (English)

    赵建; 黄建国

    2011-01-01

    为筛选出高效安全的生物化学药剂,通过平板药效试验研究了9种常用化学农药与生防菌寡雄腐霉发酵液联合施用对番茄晚疫病的防治效果.结果表明,降低化学农药的常规施用浓度,并与寡雄腐霉发酵液联用能明显抑制番茄晚疫病菌,抑菌率可达70%;代森锰锌、百菌清和多菌灵农药与寡雄腐霉发酵液联用对寡雄腐霉菌的抑制作用较小,但能有效抑制番茄晚疫病菌,达到防治番茄晚疫病和降低农药残留的双重目的.%The antibiosis of metabolites from Pythium oligandrum hyphenated with various chemical pesticides against Phytophthora infestans was studied by using inhibitory test on plate to provide theoretical basis for screening out safe biochemical reagent with high efficiency. The results showed that combined application of lower concentration of chemical pesticides and fermentation filtrate of Pythium oligandrurn could evidently inhibit tomato Phytophthora infestans and the inhibition rate could be up to 70%. The inhibition effect of combined application of mancozeb, chlorothalonil or carbendazim with fermentation filtrate of Pythium oligandrurn on Pythium oligandrurn was very small, while effectively on tomato Phytophthora infestans, which reached double purpose of preventing and curing tomato Phytophthora infestans and reducing pesticide residues in the garden stuff.

  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. Comparison of the neurotoxicities between volatile organic compounds and fragrant organic compounds on human neuroblastoma SK-N-SH cells and primary cultured rat neurons

    Directory of Open Access Journals (Sweden)

    Yasue Yamada

    2015-01-01

    Full Text Available These are many volatile organic compounds (VOCs that are synthesized, produced from petroleum or derived from natural compounds, mostly plants. Fragrant and volatile organic compounds from plants have been used as food additives, medicines and aromatherapy. Several clinical and pathological studies have shown that chronic abuse of VOCs, mainly toluene, causes several neuropsychiatric disorders. Little is known about the mechanisms of neurotoxicity of the solvents. n-Octanal, nonanal, and 2-ethyl-1-hexanol, which are used catalyzers or intermediates of chemical reactions, are released into the environment. Essential oils have the functions of self-defense, sterilization, and antibiosis in plants. When volatile organic compounds enter the body, there is the possibility that they will pass through the blood–brain barrier (BBB and affect the central nervous system (CNS. However, the direct effects of volatile organic compounds on neural function and their toxicities are still unclear. We compared the toxicities of n-octanal, nonanal and 2-ethyl-1-hexanol with those of five naturally derived fragrant organic compounds (FOCs, linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and n-phenethyl alcohol. MTT assay of human neuroblastoma SK-N-SH cells showed that the IC50 values of linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and phenethyl alcohol were 1.33, 2.3, >5, >5, and 2.39 mM, respectively, and the IC50 values of toluene, n-octanal, nonanal and 2-ethyl-1-hexanol were 850, 37.2, 8.31 and 15.1 μM, respectively. FOCs showed lower toxicities than those of VOCs. These results indicate that FOCs are safer than other compounds.

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

    Institute of Scientific and Technical Information of China (English)

    唐秋月; 陈武勇

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    唐秋月; 陈武勇

    2013-01-01

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

  1. Biocontrol Potential of Streptomyces hydrogenans Strain DH16 toward Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus

    Science.gov (United States)

    Manhas, Rajesh K.; Kaur, Talwinder

    2016-01-01

    Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v) of S. hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10%) and streptomycete cells significantly improved seed germination (75–80%) and vigor index (1167–1538). Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers. PMID:28018402

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

    Science.gov (United States)

    Kilic-Ekici, Ozlem; Yuen, Gary Y

    2003-09-01

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

  3. 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.

  4. 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.

  5. 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.

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

    Science.gov (United States)

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

    2016-11-01

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

  7. Molecular mapping of a novel gene, Grh5, conferring resistance to green rice leafhopper (Nephotettix cincticeps Uhler) in rice, Oryza sativa L.

    Science.gov (United States)

    Fujita, Daisuke; Doi, Kazuyuki; Yoshimura, Atsushi; Yasui, Hideshi

    2006-08-01

    The green rice leafhopper (GRH), Nephotettix cincticeps Uhler, is one of the most serious insect pests affecting cultivated rice (Oryza sativa L.) in temperate regions of East Asia. An accession of the wild rice species, Oryza rufipogon Griff. (W1962), was found to be highly resistant to GRH by an antibiosis test. To understand the genetic basis of the GRH resistance, a BC1F1 population derived from a cross between a susceptible Japonica variety, Taichung 65 (T65), and a highly resistant accession W1962 was analyzed by quantitative trait loci (QTL) mapping. A single major QTL for GRH resistance was detected on rice chromosome 8. A nearly isogenic population containing segments of the targeted QTL region derived from W1962 was then developed through advanced backcrossing with marker-assisted selection. Further molecular mapping using a BC4F2 population revealed that a new resistance gene, designated as Green rice leafhopper resistance 5 (Grh5), was located on the distal region of the long arm of chromosome 8 and tightly linked to the simple sequence repeat markers RM3754 and RM3761. A nearly isogenic line (NIL) carrying Grh5 was subsequently developed in the progeny of the mapping population. The resistance level of Grh5-NIL was compared with those of developed NILs for GRH resistance and was found to have the highest resistance. The DNA markers found to be closely linked to Grh5 would be useful for marker-assisted selection for the improvement of resistance to GRH in rice.

  8. 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

  9. NÃO PREFERÊNCIA PARA ALIMENTAÇÃO E ASPECTOS BIOLÓGICOS DE Spodoptera eridania EM CULTIVARES DE FEIJÃO-CAUPI

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    BRUNO HENRIQUE SARDINHA DE SOUZA

    2012-01-01

    Full Text Available The aim of this paper was to evaluate the no-preference for feeding and biological aspects of Spodoptera eridania fed on cowpea cultivars BR17 Gurgueia, BRS Urubuquara, BRS Nova Era, Sempre Verde, BRS Milênio and BR3 Tracuateua. In free-choice test, leaf discs were placed in Petri dishes where one third instar larvae per cultivar was released, whereas in no-choice test one leaf disc was placed per Petri dish where one caterpillar per cultivar was released, evaluating their attractiveness after 1, 3, 5, 10, 15, 30, 60, 120, 360 and 720 minutes, as well as the leaf area consumed. Randomized blocks and complete randomized blocks design were used for free-choice and no-choice tests, respectively, with six treatments and 10 replications. The evaluation of the biological parameters of S. eridania was carried out in Petri dishes where recently hatched caterpillars were transferred in the proportion of one per dish, and the leafs of the cultivars were offered to them during the whole larval period, and we evaluated: periods and viabilities of larvae and pupae, overall viability, weight of larvae and pupae, sex ratio, longevity and overall cycle. Complete randomized design was used with six treatments and 30 replications. In no- preference for feeding free-choice test the cultivars Sempre Verde and BR17 Gurgueia were the most and the least consumed, respectively. Regarding the effects of cowpea cultivars on larval viability we can infer that BRS Urubuquara and Sempre Verde show antibiosis-type resistance to S. eridania.

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

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    Nosir Walid

    2010-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

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    Roda Fornaguera Federico

    2006-12-01

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

  14. Biocontrol Potential of Streptomyces hydrogenans strain DH16 Towards Alternaria brassicicola to Control Damping Off and Black Leaf Spot of Raphanus sativus

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    Rajesh Kumari Manhas

    2016-12-01

    Full Text Available Biocontrol agents and their bioactive metabolites provide one of the best alternatives to decrease the use of chemical pesticides. In light of this, the present investigation reports the biocontrol potential of Streptomyces hydrogenans DH16 and its metabolites towards Alternaria brassicicola, causal agent of black leaf spot and damping off of seedlings of crucifers. In vitro antibiosis of strain against pathogen revealed complete suppression of mycelial growth of pathogen, grown in potato dextrose broth supplemented with culture supernatant (20% v/v of Streptomyces hydrogenans DH16. Microscopic examination of the fungal growth showed severe morphological abnormalities in the mycelium caused by antifungal metabolites. In vivo studies showed the efficacy of streptomycete cells and culture supernatant as seed dressings to control damping off of Raphanus sativus seedlings. Treatment of pathogen infested seeds with culture supernatant (10% and streptomycete cells significantly improved seed germination (75-80% and vigour index (1167-1538. Furthermore, potential of cells and culture supernatant as foliar treatment to control black leaf spot was also evaluated. Clearly visible symptoms of disease were observed in the control plants with 66.81% disease incidence and retarded growth of root system. However, disease incidence reduced to 6.78 and 1.47% in plants treated with antagonist and its metabolites, respectively. Additionally, treatment of seeds and plants with streptomycete stimulated various growth traits of plants over uninoculated control plants in the absence of pathogen challenge. These results indicate that S. hydrogenans and its culture metabolites can be developed as biofungicides as seed dressings to control seed borne pathogens, and as sprays to control black leaf spot of crucifers.

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

    Institute of Scientific and Technical Information of China (English)

    孙立军; 郭玉蓉; 田兰兰

    2012-01-01

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

  16. 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.

  17. St. Augustine grass germplasm resistant to Blissus insularis (Hemiptera: Blissidae).

    Science.gov (United States)

    Youngs, Katharine M; Milla-Lewis, Susana R; Brandenburg, Rick L; Cardoza, Yasmin J

    2014-08-01

    St. Augustine grass (Stenotaphrum secundatum (Walter) Kuntze) is an economically important turfgrass in the southeastern United States. However, this turf species is prone to southern chinch bug, Blissus insularis Barber (Heteroptera: Blissidae) outbreaks. This insect is the most destructive pest of St. Augustine grass wherever this turf grass is grown. Host plant resistance has historically been an effective management tool for southern chinch bug. Since 1973, the 'Floratam' St. Augustine grass cultivar effectively controlled southern chinch bug in the southeast. However, southern chinch bug populations from Florida and Texas have now circumvented this resistance, through mechanisms still unknown. Therefore, identifying and deploying new cultivars with resistance to the southern chinch bug is imperative to combat this pest in an economically and environmentally sustainable manner. Currently, the number of cultivars with resistance against southern chinch bug is limited, and their efficacy, climatic adaptability, and aesthetic characters are variable. Hence, the main focus of this study is the identification of alternative sources of resistance to southern chinch bugs in previously uncharacterized St. Augustine grass plant introductions (PIs) and its closely related, crossbreeding species, Pembagrass (Stenotaphrum dimidiatum (L.) Brongniart). The PIs exhibited a wide range of responses to southern chinch bug feeding, as indicated by damage ratings. Damage ratings for seven PIs grouped with our resistant reference cultivars. Moreover, nine PIs exhibited antibiosis, based on poor development of southern chinch bug neonates, when compared with our susceptible reference cultivars. Altogether our study has produced strong support to indicate these materials are good candidates for future southern chinch bug resistance breeding in St. Augustine grass.

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Science.gov (United States)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2016-04-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  1. Microflora en semillas de frijol

    Directory of Open Access Journals (Sweden)

    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

  2. 1例乳腺癌患者手术及化疗期间的药学监护%Pharmaceutical care of one patient with breast cancer during operation and chemotherapy

    Institute of Scientific and Technical Information of China (English)

    张鹏飞

    2012-01-01

    目的 说明如何对老年合并高血压的乳腺癌患者进行药学监护及药学监护对患者的重要性.方法临床药师参与1例老年合并高血压的乳腺癌患者治疗过程,对患者进行药学监护,为临床提供合理化用药方案,即时处理用药后的不良反应.结果 在临床药师的药学监护下,患者在围术期,抗菌使用合理,无切口感染;在化疗期,化疗药物安全使用,保证了手术和化疗的顺利进行.结论临床药师深入临床,参与药物治疗,不仅保证了临床用药的安全、有效,还为患者减轻了经济负担.%Objective To explain how to implement pharmaceutical care for elder patients with breast cancer complicated by hypertension and the importance of pharmaceutical care to patients. Methods The clinical pharmacists participated in the treatment course of one elder patient with breast cancer complicated by hypertension, provided pharmaceutical care for the patient, provided rationalized drug administration schedule and timely managed post-administration adverse reactions. Results Under the pharmaceutical care of the clinical pharmacists, in the perioperative period, the patient received reason -able antibiosis and had no wound infection, and in the chemotherapy period, the chemotherapy drugs were safely used, which ensured the smooth progress of surgery and chemotherapy. Conclusion The clinical pharmacists deeply involved in the clinical drug treatment not only ensure the safety and effectiveness of clinical medication, but also reduce the financial burden for patients.

  3. 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

  4. 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

  5. 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

  6. 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.

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

    Institute of Scientific and Technical Information of China (English)

    吴贤波; 陈颖; 戴敏; 马萍

    2013-01-01

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

  8. A trio of viral proteins tunes aphid-plant interactions in Arabidopsis thaliana.

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    Jack H Westwood

    Full Text Available BACKGROUND: Virus-induced deterrence to aphid feeding is believed to promote plant virus transmission by encouraging migration of virus-bearing insects away from infected plants. We investigated the effects of infection by an aphid-transmitted virus, cucumber mosaic virus (CMV, on the interaction of Arabidopsis thaliana, one of the natural hosts for CMV, with Myzus persicae (common names: 'peach-potato aphid', 'green peach aphid'. METHODOLOGY/PRINCIPAL FINDINGS: Infection of Arabidopsis (ecotype Col-0 with CMV strain Fny (Fny-CMV induced biosynthesis of the aphid feeding-deterrent 4-methoxy-indol-3-yl-methylglucosinolate (4MI3M. 4MI3M inhibited phloem ingestion by aphids and consequently discouraged aphid settling. The CMV 2b protein is a suppressor of antiviral RNA silencing, which has previously been implicated in altering plant-aphid interactions. Its presence in infected hosts enhances the accumulation of CMV and the other four viral proteins. Another viral gene product, the 2a protein (an RNA-dependent RNA polymerase, triggers defensive signaling, leading to increased 4MI3M accumulation. The 2b protein can inhibit ARGONAUTE1 (AGO1, a host factor that both positively-regulates 4MI3M biosynthesis and negatively-regulates accumulation of substance(s toxic to aphids. However, the 1a replicase protein moderated 2b-mediated inhibition of AGO1, ensuring that aphids were deterred from feeding but not poisoned. The LS strain of CMV did not induce feeding deterrence in Arabidopsis ecotype Col-0. CONCLUSIONS/SIGNIFICANCE: Inhibition of AGO1 by the 2b protein could act as a booby trap since this will trigger antibiosis against aphids. However, for Fny-CMV the interplay of three viral proteins (1a, 2a and 2b appears to balance the need of the virus to inhibit antiviral silencing, while inducing a mild resistance (antixenosis that is thought to promote transmission. The strain-specific effects of CMV on Arabidopsis-aphid interactions, and differences

  9. 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

  10. Advances in the Mechanism Study of Borer Resistance in Sugarcane%甘蔗对螟虫的抗性及其机制研究进展

    Institute of Scientific and Technical Information of China (English)

    甘仪梅; 曾凡云; 张树珍; 杨本鹏

    2012-01-01

    Sugarcane is the main sugar crop and energy crop. Borer is a major pest to sugarcane, which can significantly reduce the yield and quality of sugarcane. Although cchemicalontrol and integrated pests management are common for control of borer, success is often limited due to practical difficulties. Breeding sugarcane cultivars with insect resistance allows the most effective and low—cost control of strip borer populations. The main resistance mechanisms are larvae antixenosis and antibiosis in resistant way. This article reviews the research advances concerning the methods of resistant identification based on field and laboratory trials, respectively, and the relationship of resistance with physical structure (including stem hardness, fiber content, silicon content) and physiological and biochemical factors (including flavonoid, nitrogen and essential amino acids). The function of physical structure and physiological and biochemical factors in borer resistance were elucidated. Also, this article discussed the resistance mechanisms based on the sources of resistance.%甘蔗是主要的糖料作物和能源作物,螟虫是甘蔗生产中为害最严重的钻蛀性害虫,使甘蔗的产量和品质显著降低.尽管目前普遍采用化学药剂和生物防治方法,但因甘蔗的特殊性使防治效果甚微.利用品种的抗虫性是最为经济有效的防治方法.从抗性方式来看,甘蔗抗螟虫性机制主要是幼虫的排趋性和抗生性.本文从甘蔗对螟虫的田间抗性鉴定、室内抗性鉴定讨论了抗性鉴定方法,以及茎表皮硬度、纤维素含量、硅含量等物理结构特性和类黄酮、氮素和必需氨基酸等化学因子与抗性的关系,阐述了物理结构和化学因子在甘蔗对螟虫抗性机制中的作用,最后从抗性来源等方面探讨抗性机制的研究,并对今后的研究方向提出展望.

  11. 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.

  12. 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

  13. 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.

  14. 聚球藻Synechococcus sp.中活性物质分离及活性研究%Separation of activated Compounds from Synechococcus sp.and the Bioactivities

    Institute of Scientific and Technical Information of China (English)

    赵小惠; 孙利芹; 刘红辉; 汲红丽; 卫东

    2013-01-01

    Marine microalga Synechococcus is one of Cyanobacteria. In order to investigate the bioactivity components of Synechococcus,three organic solvent petroleum ether,ethyl acetate and normal butanol were used to extract the ethanol extractum of Synechococcus, respectively, and three kinds of organic phase crude extracts were obtained. Then the antibiosis and antioxidant activities of crude extracts were detected. The chemical components of crude extracts were analyzed by GC-MS chromatogram.and 20 components of petroleum ether phase and normal butanol phase were determined, respectively. The activity tracking results showed that the best antibacterial and antioxidant effects of crude extracts were observed in petroleum ether phase,followed by ethyl acetate and normal butanol phase. The aqueous extracts had not bioactivities. Subsequently .Silica gel column chromatography, gel Sephadex LH-20 chromatography and lamina chromatogra-phy were used to separate and purify the compound from petroleum ether phase, and a monomeric compound was obtained, the structure of compound was elucidated as β-sitosterol by the means of 1H NMR、13C NMR etc. spectrum technology.%分别采用石油醚、乙酸乙酯和正丁醇对聚球藻(Synechococcus)乙醇浸膏进行萃取,获得三种有机相粗提物,其后跟踪检测其抗菌、抗氧化活性,并采用GC-MS分析粗提取的化学组成,确定了石油醚相和正丁醇相的各20种成分.活性跟踪结果显示,石油醚相萃取物的抗菌和抗氧化效果最好,其次为乙酸乙酯相和正丁醇相,水相提取物没有抗菌和抗氧化活性.对活性较好的石油醚相依次进行硅胶柱层析,凝胶Sephadex LH-20层析,制备薄层层析,分离获得一单体化合物,应用1H NMR、13C NMR等波谱技术分析鉴定化合物结构为β-谷甾醇.

  15. 樱桃园土壤优势放线菌的分离及其促长功能研究%Isolation of Dominant Actinomycetes from Cherry Orchard Soil and Their Functions in Bio-Control and Plant Promotion

    Institute of Scientific and Technical Information of China (English)

    刘灵芝; 秦嗣军; 吕德国; 王冰营

    2013-01-01

    explored through 16S rDNA sequence analysis to ascertain its taxonomic status.[Result] There were 32 dominant actinomycetes were isolated from Cerasus avium (L.)Moench / C.sachalinensis (L.) Kom.Rhizosphere soil at different growth stages.The number of soil actinomycetes in August was the highest compared with that in May and November.The isolates from different growth stages also varied in their microorganism inhibiting and plant growth promoting capabilities.In general,isolates from August 2010 expressed obvious effect on antagonistic pathogen and plant growth promotion.Among all the 32 isolates,strain F4-5 showed a significant inhibitive effect on 4 tested bacteria including Staphylococcus aureus,Escherichia coli,Bacillus subtilis and B.cereus,as well as 3 tested fungi including Trichoderma viride,Rhizopus stolo and Aspergillus niger,exhibiting a broad-spectrum antibiosis.In the experiment of seeding growth of Malus baccata (L.) Brokh.,strain F4-5 also displayed a positive effect on seed germination and root growth,increased by 201.1% and 43.5%,respectively,compared with the control,indicating both antibiosis and plant promoting effects.In addition,strain F4-5 was identified as Streptomyces flavogriseum,according to the morphological characteristics,cultural characteristics and 16S rDNA sequence analysis.[Conclusion] The actinomycete number,distribution,antibiotic and seed germination promotion in Cerasus avium (L.) Moench / C sachalinensis (L.) Kom.Rhizosphere soil varied greatly at different stages.The proper strain F4-5 (S.flavogriseum) screened from 32 actinomycete strains showed a good probiotic role and seed germination promotion.

  16. 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

    Directory of Open Access Journals (Sweden)

    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

  17. 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.

    Directory of Open Access Journals (Sweden)

    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

  18. Rationale for one stage exchange of infected hip replacement using uncemented implants and antibiotic impregnated bone graft.

    Science.gov (United States)

    Winkler, Heinz

    2009-09-04

    biomechanical properties. Efficient cementing techniques will result in tight bonding with the underlying bone, making eventual removal time consuming and possibly associated with further damage to the osseous structures. All these issues are likely to make uncemented revisions more desirable. Allograft bone may be impregnated with high loads of antibiotics using special incubation techniques. The storage capacities and pharmacological kinetics of the resulting antibiotic bone compound (ABC) are more advantageous than the ones of antibiotic loaded cement. ABC provides local concentrations exceeding those of cement by more than a 100fold and efficient release is prolonged for several weeks. The same time they are likely to restore bone stock, which usually is compromised after removal of an infected endoprosthesis. ABC may be combined with uncemented implants for improved long term results and easy removal in case of a failure. Specifications of appropriate designs are outlined. Based on these considerations new protocols for one stage exchange of infected TJR have been established. Bone voids surrounding the implants may be filled with antibiotic impregnated bone graft; uncemented implants may be fixed in original bone. Recent studies indicate an overall success rate of more than 90% without any adverse side effects. Incorporation of allografts appears as after grafting with unimpregnated bone grafts. Antibiotic loaded bone graft seems to provide sufficient local antibiosis for protection against colonisation of uncemented implants, the eluted amounts of antibiotics are likely to eliminate biofilm remnants, dead space management is more complete and defects may be reconstructed efficiently. Uncemented implants provide improved long term results in case of success and facilitated re-revision in case of failure. One stage revision using ABC together with uncemented implants such should be at least comparably save as multiple stage procedures, taking advantage of the obvious

  19. Rationale for one stage exchange of infected hip replacement using uncemented implants and antibiotic impregnated bone graft

    Directory of Open Access Journals (Sweden)

    Heinz Winkler

    2009-01-01

    reduces its biomechanical properties. Efficient cementing techniques will result in tight bonding with the underlying bone, making eventual removal time consuming and possibly associated with further damage to the osseous structures. All these issues are likely to make uncemented revisions more desirable. Allograft bone may be impregnated with high loads of antibiotics using special incubation techniques. The storage capacities and pharmacological kinetics of the resulting antibiotic bone compound (ABC are more advantageous than the ones of antibiotic loaded cement. ABC provides local concentrations exceeding those of cement by more than a 100fold and efficient release is prolonged for several weeks. The same time they are likely to restore bone stock, which usually is compromised after removal of an infected endoprosthesis. ABC may be combined with uncemented implants for improved long term results and easy removal in case of a failure. Specifications of appropriate designs are outlined. Based on these considerations new protocols for one stage exchange of infected TJR have been established. Bone voids surrounding the implants may be filled with antibiotic impregnated bone graft; uncemented implants may be fixed in original bone. Recent studies indicate an overall success rate of more than 90% without any adverse side effects. Incorporation of allografts appears as after grafting with unimpregnated bone grafts. Antibiotic loaded bone graft seems to provide sufficient local antibiosis for protection against colonisation of uncemented implants, the eluted amounts of antibiotics are likely to eliminate biofilm remnants, dead space management is more complete and defects may be reconstructed efficiently. Uncemented implants provide improved long term results in case of success and facilitated re-revision in case of failure. One stage revision using ABC together with uncemented implants such should be at least comparably save as multiple stage procedures, taking advantage of

  20. 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

    Directory of Open Access Journals (Sweden)

    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

  1. 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

    Directory of Open Access Journals (Sweden)

    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.

  2. 药用植物鸦胆子内生细菌分离及其抑菌活性研究%Isolation of endophytic bacteria from medicinal plant Brucea javanica L. Merr. and its antifungal activity

    Institute of Scientific and Technical Information of China (English)

    梁子宁; 赖开平; 朱华; 韦茂春; 陈龙

    2014-01-01

    [Objective]Endophytic bacteria with antagonistic activity were isolated from medicinal plant Brucea javanica L. Merr. to provide references for developing new biological fungicides. [Method]The endophytic bacteria were isolated by tis-sue homogenization and the strains with antifungal activity were screened by in vitro and in vivo antifungal tests. The strains with stronger inhibitory activity was identified based on morphology, physiological and biochemical characteristics, 16S rDNA sequence analysis and Biolog test. [Result]There were 43, 19, 15 and 8 isolates obtained from root, leaf, stem and fruit of Brucea javanica, respectively. Especially, the strain YGB-11 isolated from root showed good antibiosis characteristics with antibacterial rate over 80.00%to Penicillium digitatum (pers.ex Fr.)Sacc of Citrus green mold and Helminthosporium torulosum (Syd.) Ashby of banana helminthosporium leaf spot. Based on morphological, physiological and biochemical characteristics, 16S rDNA sequence analysis and Biolog test, the strain YGB-11 was identified as Bacillus amyloliquefacien. [Conclusion]With wide antimicrobial spectrum and high antifungal activities, YGB-11 has promising prospects.%【目的】从药用植物鸦胆子中分离对植物病原真菌具有拮抗活性的内生细菌,为新型生物杀菌剂的开发提供依据。【方法】采用组织匀浆法对鸦胆子内生细菌进行分离,通过离体和活体组织抑菌试验筛选活性菌株;根据形态特征、生理生化测定、16S rDNA序列分析和Biolog系统对筛选获得的高活性菌株进行鉴定。【结果】从鸦胆子的根、叶、茎和果实部位分别分离得到43、19、15和8株内生细菌,其中分离自根部的YGB-11菌株对柑桔绿霉病菌、香蕉煤纹病菌等7种植物病原菌的抑菌率均超过80.00%,表现出较好的抗菌特性,结合形态特征、生理生化特征、16S rDNA序列分析和Biolog系统鉴定,确定YGB-11菌株

  3. Resistência de meloeiro a Bemisia Tabaci biótipo B Resistance of melon to Bemisia Tabaci biotype B

    Directory of Open Access Journals (Sweden)

    Sérgio Alexandre Mottola Pereira Coelho

    2009-01-01

    whitefly. As to adult attractiveness, 'Neve' had the lowest number of adults on the abaxial surfaces of leaves (0.6 adult/10cm² while 'Nilo' was the more attractive (5.6 adults/10cm². The oviposition preference was evaluated in free-choice and no-choice tests. In both, 'Neve' was less oviposited and 'Nilo' had the highest number of eggs. The silverleaf whitefly colonization was evaluated by scores varying from 0 (no colonization to 6 (leaves completely colonized. While 'Neve' showed the lowest level of colonization, high levels were observed in 'Imperial', 'Jangada', 'Vereda', 'Deneb' and 'Nilo'. The B. tabaci biotype B egg-adult cycle varied from 24.0 ('Neve' to 25.4 days ('Jangada', without any significant differences among the genotypes. The lowest rates of adult emergence were observed in 'Vereda' (68.2% and 'Nilo' (69.3%, suggesting that antibiosis is the mechanism of resistance, while 'Imperial' (90.9% and 'Deneb' (89.6% presented the highest rates. Considering the evaluated characteristics, 'Neve' is the most resistant cultivar to silverleaf whitefly and should be tested in highly infested areas. Additionally, it might be a valuable source of resistance for breeding programs.

  4. Discussion on intervention strategies for 13 496 cases of prophylactic use of antibiotics during perioperative period%13496例围术期抗菌药物预防使用的干预策略

    Institute of Scientific and Technical Information of China (English)

    糜琛蓉; 倪语星; 李文慧; 杨莉; 徐桂婷; 张祎博; 袁克俭

    2011-01-01

    OBJECTIVE To improve the rationality of use of antibiotics during perioperative period through investigation feedback and intervention of prophylactil use of antibiotics. METHODS Make a sample check in no signs of infection surgical cases at regular intervals from 2005 to 2010. After statistical analysis, we feedback the result and improvement request to the head of department and the president. we have statistical analysis 13 496 surgical cases without infection. RESULTS After intervention, the hospital antimicrobial usage increased obviously, the antibiosis using rate into the operating room rise from 51.19% to 99. 27%, Ⅰ type of surgery perioperative antimicrobial usage days, shortened from average 6. 29 days/cases to average 3.30 days/example.Antimicrobial usage levels rise gradually, from 18.21% to 74.70%, whole 56.49% rise. Hospital infection rates haven't rise. CONCLUSION Formulating clear requirements of perioperative arrtimicrobial usage, using the computernetwork to back-stage management, statistical analysis the monitoring data scientifically, listening to the clinical opinions, examining to people, attaching importance by the leader are the keys of improving the perioperative antimicrobial drugs using.%目的 通过调查与反馈,干预院内围术期抗菌药物预防使用,提高围术期抗菌药物使用的合理性.方法 定期抽查2005-2010年全院无感染征象的手术病例13 496例,与此同时采取各种干预措施,规范围术期抗菌药物预防使用.结果 通过干预,全院抗菌药物带人手术室使用率明显上升,从51.19%上升至99.27%,上升了47.71%;Ⅰ类手术围手术期抗菌药物使用天数从平均6.29 d/例下降至3.30 d/例,平均下降2.99 d/例;抗菌药物使用级别合格率逐渐上升,从18.21%上升至74.70%,上升56.49%,医院感染率没有上升.结论 制定明确的围术期抗菌药物使用要求,应用计算机后台管理系统,对监测数据进行科学的统计分析,深入

  5. 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

  6. 钛表面人工肽抑制格登链球菌生长的实验研究%Effects of the synthetic peptide coatings inhibiting the growth of Streptococcus gordonii on titanium surface

    Institute of Scientific and Technical Information of China (English)

    马勍; 张溪; 张旭; 孙迎春; 高平

    2016-01-01

    目的:检测自主设计合成的人工肽在钛表面的吸附情况及吸附后的抗菌效果,为种植体抗菌的实验研究提供新的思路。方法使用ExPASy ProtParam、ProtScale软件、圆二色光谱和Zeta电位仪等,分析或测定人工肽与抗菌肽的各项理化性质及结构特征。利用常温孵育的方法将人工肽锚定于钛表面。使用X射线光电子能谱与原子力显微镜检测人工肽在钛表面的吸附。通过共聚焦激光显微镜观察锚定于钛表面的人工肽对格登链球菌的抑菌作用。使用透射电镜检测游离人工肽与抗菌肽对格登链球菌结构的破坏作用。结果自主设计合成的人工肽仍具有抗菌肽发挥抗菌作用所需的各项理化性质及结构特征。在孵育于5 g/L人工肽的PBS溶液中的钛片表面即可检测到人工肽的吸附,且该试件对格登链球菌的存活及黏附均有一定的抑制效果。结论自主设计合成的人工肽实现了在钛表面吸附并抑制格登链球菌生长的设想。%Objective To detect the independently designed synthetic peptide adsorbed to the titanium surface and its inhibitory effect on streptococcus gordonii, and to provide a new means for antibiosis reseach on oral implants. Methods The physical and chemical properties of the synthetic peptide and antimicrobial peptide were measured by ExPASy Prot⁃Param tool, ProtScale analysis, circular dichroism and Zeta potential instrument. The synthetic peptide was anchored on the surface of the titanium specimen through incubation at room temperature. The adsorption of the synthetic peptide to the titani⁃um surface was examined by X-ray photoelectron spectroscopy (XPS) and the atomic force microscope (AFM). The inhibitory effect on streptococcus gordonii of the synthetic peptide fixed on the titanium surface was viewed by confocal laser scanning microscopy (CLSM). The destructive effects of the synthetic peptide and the antimicrobial peptide on

  7. 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

  8. Inhititory Mechanisms of Metarhizium anisopliae Against Rhizoctonia cerealis%绿僵菌对小麦纹枯病菌的抑制作用研究

    Institute of Scientific and Technical Information of China (English)

    齐永霞; 陈方新; 李增智

    2011-01-01

    The inhibition and mechanism of Metarhizium anisopliae against Rhizoctonia cerealis was studied in vitro by applying dual-culture, cup-plate test and microscopy, respectively. The results showed that in dual-culture tests and cupplate tests, the tested M. Anisopliae had strong antagonism against the tested R. Cerealis. It suggested that the inhibitory effects of the tested M. Anisopliae on the tested R. Cerealis were significant when it was dual-cultured and when its conidia suspension was applied into the PDA media. Using metabolic liquid of Ma55, which was cultured in different time, the inhibitions to hyphal growth, sclerotium-formation number and sclerotium weight, sclerotium-germinating rate were studied, too. The results showed that the metabolic liquid cultured 25 d has significant inhibitory effect on hyphal growth, sclerotium number and sclerotium-germinating rate. The test indicated that the culture filtrates of Ma55 contained a thermal stable antifungal compound. It was also observed that the hyphal of Metarhizium anisopliae and Rhizoctonia cerealis has no hyper parasitism, but the hyphal of Rhizoctonia cerealis was lysed, broken and their cytoplasm becamethinning on dual culture. The results mentioned above indicated that the inhibitory effects of Metarhizium anisopliae against the pathogen of wheat sharp eyespot were produced mostly by nutrition competition, space competition and antibiosis.%在实验室条件下,研究了金龟子绿僵菌(Metarhizium anisopliae)对小麦纹枯病菌(Rhizoctonia cerealis)的拮抗作用及其机理.结果表明,金龟子绿僵菌与小麦纹枯病菌对峙培养以及在培养基中加入金龟子绿僵菌孢子悬浮液,对小麦纹枯病菌菌丝生长均有较好的抑制作用.测定了培养不同天数的金龟子绿僵菌Ma55发酵液对小麦纹枯病菌菌丝生长、菌核产生量及菌核萌发率的影响.结果表明,液体振荡培养25 d的金龟子绿僵菌Ma55发酵液对小麦纹枯病菌的菌丝

  9. 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

  10. 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.

  11. 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

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

    Institute of Scientific and Technical Information of China (English)

    李瑞奇; 苗明三

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    张勇; 郭夫江; 曾鹏; 贾琦; 李医明; 朱维良; 陈凯先

    2012-01-01

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