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Sample records for bacterial wilt

  1. Effect of ectomycorrhizal fungi on bacterial wilt of Eucalyptus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Bacterial wilt caused by Pseudomonas solanacearum, is a very serious disease of Eucalyptus in southern China, mainly in Guangdong, Hainan and Guangxi provinces. It causes the death of seedlings and young trees and the mortality may exceed 90 percent in some sites. Susceptible species include E. grandis, E. urophylla, hybrids between the two and E. citriodora. In nursery and field trials with E. urophylla and field trial with E. grandis x E. urophylla inoculation of ectomycorrhizal fungi was found to red...

  2. Increased susceptibility to bacterial wilt in tomatoes by nematode galling and the role of the Mi gene in resistance to nematodes and bacterial wilt

    OpenAIRE

    Deberdt, P.; Quénéhervé, Patrick; Darrasse, A; Prior, P

    1999-01-01

    The soil-borne bacterial pathogen #Ralstonia solanacearum$ commonly coexists with polyspecific nematode populations in tropical and subtropical areas. The wounding of roots by nematodes is usually invoked to explain the correlation between nematode infection and bacterial wilt, since this wounding increases the number of sites for bacterial entry. Bacterial wilt development on tomato was investigated in a controlled environment on the susceptible tomato cultivar Floradel and the polygenically...

  3. Enterobacter spp.: A new evidence causing bacterial wilt on mulberry

    Institute of Scientific and Technical Information of China (English)

    PRAPHAT; Kawicha

    2010-01-01

    Thirty-six pathogenetic bacterial strains were isolated from wilted mulberry plants in Hangzhou,Zhejiang province of China.The six representative strains were confirmed to be involved in more than one Enterobacter species by common bacteriological test,electron microscope observation,hypersensitive reaction,Koch’s postulates,physiological and biochemical test,biolog,fatty acid methyl esters analysis (FAMEs),enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR),16s rRNA sequences analysis,and comparative analysis with 7 type strains and 3 reference strains.This is the first report on mulberry disease caused by Enterobacter spp.in the world providing new evidence on induction of the plant disease in this genus.The results are not only important in the mulberry disease management but also have significant scientific value for further studies of opportunistic human pathogens and environmental strains in Enterobacter.

  4. Towards allele mining of bacterial wilt disease resistance gene in tomato

    International Nuclear Information System (INIS)

    Tomato (Lycopersicon esculentum Mill.) is the most important vegetable commodity of the Philippines. Bacterial wilt caused by Ralstonia solanacearum is one serious constraint in tomato production particularly during off-season planting. A major locus derived from H7996 that confers resistance to bacterial wilt has been mapped in the tomato genome. To validate the biological function of the resistance locus and generate multiple allele -mimics-, targeted mutation was induced in tomato using gamma ray and ethyl methane sulfonate (EMS) mutagens. Suitable mutagen treatment was established by evaluating a wide range of mutagen doses/concentrations for a) percent seed germination, b) reduction in plant height, and c) loss of resistance. Six hundred Gy and 1.0% EMS were identified to generate large M1 families of H7996. From 10,000 initial seeds treated with either gamma ray or EMS, a total of 3,663 M1 plants were generated. M2 seeds were harvested from all surviving M1 plants. Several DNA markers have been resourced and are being developed specific to the bacterial wilt resistant gene. In the large M2 population, of H7996, both the phenotypic manifestation of bacterial wilt susceptibility and nucleotide changes in the resistance locus will be evaluated. Large M3 families for the different allele series of the bacterial wilt resistance gene will be established for future high throughput TILLING (Targeting Induced Local Lesions in Genomes) analysis in the gene region

  5. Comparison of Bacterial Community Structures in the Rhizoplane of Tomato Plants Grown in Soils Suppressive and Conducive towards Bacterial Wilt

    OpenAIRE

    Shiomi, Yoshitaka; Nishiyama, Masaya; Onizuka, Tomoko; Marumoto, Takuya

    1999-01-01

    It has been reported that the growth of Ralstonia solanacearum is suppressed at the rhizoplane of tomato plants and that tomato bacterial wilt is suppressed in plants grown in a soil (Mutsumi) in Japan. To evaluate the biological factors contributing to the suppressiveness of the soil in three treated Mutsumi soils (chloroform fumigated soil; autoclaved soil mixed with intact Mutsumi soil; and autoclaved soil mixed with intact, wilt-conducive Yamadai soil) infested with R. solanacearum, we bi...

  6. Identification of Genes Induced in Lolium multiflorum by Bacterial Wilt Infection

    DEFF Research Database (Denmark)

    Wichmann, Fabienne; Asp, Torben; Widmer, Franco; Kölliker, Roland

    Xanthomonas translucens pv. graminis(Xtg) causes bacterial wilt in many forage grasses including Italian ryegrass (Lolium multiflorum Lam), seriously reducing yield and quality. Breeding for resistance is currently the only practicable means of disease control. Molecular markers closely linked to...... resistance genes or QTL could complement and support phenotypic selection. We used comparative gene expression analysis of a partially resistant L. multiflorum genotype infected and not infected with Xtg to identify genes involved in the control of resistance to bacterial wilt. The genes differentially...... expressed upon infection will serve as the basis for the identification of key genes involved in bacterial wilt resistance and to develop molecular markers for marker assisted breeding. Fluorescently labelled cDNA prepared from plant leaves collected at four different time points after infection was...

  7. Evaluation of bacterial wilt resistance in tomato lines nearly isogenic for the Mi gene for resistance to root-knot

    OpenAIRE

    Deberdt, P.; Olivier, J; Thoquet, P; Quénéhervé, Patrick; Prior, P

    1999-01-01

    Resistance to bacterial wilt, caused by #Ralstonia solancearum$, in tomato lines CRA 66 and Caraïbo is reported to be decreased by root-knot nematode galling and by introduction of the #Mi$ gene for nematode resistance. The #Mi$ gene is located on tomato chromosome 6, which also carries a major quantitative trait locus (QTL) for resistance to bacterial wilt. Bacterial wilt resistance was evaluated in F3-progenies derived from two crosses between near-isogenic lines Caraïbo x Carmido and CRA 6...

  8. Ralstonia solanacearum Pectin Methylesterase Is Required for Growth on Methylated Pectin but Not for Bacterial Wilt Virulence

    OpenAIRE

    Tans-Kersten, Julie; Guan, Yanfen; Allen, Caitilyn

    1998-01-01

    Ralstonia (Pseudomonas) solanacearum causes bacterial wilt, a serious disease of many crop plants. The pathogen produces several extracellular plant cell wall-degrading enzymes, including polygalacturonases (PGs) and pectin methylesterase (Pme). Pme removes methyl groups from pectin, thereby facilitating subsequent breakdown of this cell wall component by PGs, which are known bacterial wilt virulence factors. R. solanacearum PGs could not degrade 93% methylated pectin unless the substrate was...

  9. Recent Trends in Control Methods for Bacterial Wilt Diseases Caused by Ralstonia solanacearum

    OpenAIRE

    Yuliar,; Nion, Yanetri Asi; Toyota, Koki

    2015-01-01

    Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomy...

  10. Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato.

    Science.gov (United States)

    Kwak, A Min; Min, Kyeong Jin; Lee, Sang Yeop; Kang, Hee Wan

    2015-09-01

    Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding β-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction. PMID:26539048

  11. Effect of a rock dust amendment on disease severity of tomato bacterial wilt.

    Science.gov (United States)

    Li, Jian-Gang; Dong, Yuan-Hua

    2013-01-01

    Nutrients are important for growth and development of plants and microbes, and they are also important factors in plant disease control. The objective of this study was to evaluate the effect of a rock dust used as a fertilizer in maintaining health of soil and tomato plants under greenhouse conditions. Four treatments-including M (commercial organic fertilizer), A (rock dust soil amendment), M + A (commercial organic fertilizer + rock dust soil amendment) and CK (blank control)--were examined for their effect on soil properties, soil enzymatic activity, plant growth and control efficacy against tomato bacterial wilt. Treatments A and M + A were significantly better than other treatments in changing soil pH, increasing it from acidic (pH 5.13) to nearly neutral (pH 6.81 and 6.70, respectively). Enzymatic activities in soil were notably influenced by the different treatments--particularly treatment M + A, which increased the activities of alkaline phosphatase, urease, catalase and sucrase to a greater extent in soil. There was no significant difference (P effects of treatments A and M + A on tomato plant height, stem diameter and biomass. The effect of the four treatments on the chlorophyll content and photosynthetic rate (in decreasing order) were M + A, A, M and CK. The replicate greenhouse experiments showed that the control efficacies of treatments M + A, A, and M against bacterial wilt were respectively 89.99, 81.11 and 8.89 % in first experiment and with the efficacies of 84.55, 74.36, and 13.49 % in the replicate; indicating that rock dust played a key role in the plant-soil interaction. The raised soil pH and Ca content were the key factors for the rock dust amendment controlling bacterial wilt under greenhouse conditions. PMID:22847260

  12. Isolation of Bacillus amyloliquefaciens S20 and its application in control of eggplant bacterial wilt.

    Science.gov (United States)

    Chen, Da; Liu, Xin; Li, Chunyu; Tian, Wei; Shen, Qirong; Shen, Biao

    2014-05-01

    Bacterial strain S20 was isolated and identified as Bacillus amyloliquefaciens based on physiological and biochemical characteristics and a 16S rRNA gene sequence analysis. Strain S20 inhibits the growth of Fusarium oxysporum and Ralstonia solanacearum. Some genes associated with the synthesis of some lipopeptides were detected in strain S20 by PCR. Iturins A were identified as the main antagonistic substrates by analysis with electrospray ionization mass spectrometry/collision-induced dissociation (ESI-MS/CID). Four homologues of iturin A (C13-C16) were identified. Pot experiments showed that the application of strain S20 alone could control eggplant wilt with an efficacy of 25.3% during a 40 day experiment. If strain S20 was used with organic fertilizer, the control efficacy against eggplant wilt reached as high as 70.7%. The application of organic fertilizer alone promotes the growth of R. solanacearum, resulting in a higher wilt incidence than that observed in control plants. The application of strain S20 effectively inhibits R. solanacearum in the rhizosphere soil of eggplant. The combined use of strain S20 and organic fertilizer more effectively controlled R. solanacearum in soil than the use of strain S20 alone. The soil count of strain S20 decreased gradually during the course of the experiment after inoculation. Organic fertilizer was beneficial for the survival of the antagonistic bacterial strain S20; a higher level of these bacteria could be maintained. The application of organic fertilizer with strain S20 increased bacterial diversity in rhizosphere soil. PMID:24632400

  13. Selection and Characterization of Endophytic Bacteria as Biocontrol Agents of Tomato Bacterial Wilt Disease

    Directory of Open Access Journals (Sweden)

    ABDJAD ASIH NAWANGSIH

    2011-06-01

    Full Text Available Biological control of bacterial wilt pathogen (Ralstonia solanacearum of tomato using endophytic bacteria is one of the alternative control methods to support sustainable agriculture. This study was conducted to select and characterize endophytic bacteria isolated from healthy tomato stems and to test their ability to promote plant growth and suppress bacterial wilt disease. Among 49 isolates successfully isolated, 41 were non-plant pathogenic. Green house test on six selected isolates based on antagonistic effect on R. solanacearum or ability to suppress R. solanacearum population in dual culture assays obtained BC4 and BL10 isolates as promising biocontrol agents. At six weeks after transplanting, plants treated with BC4 isolate showed significantly lower disease incidence (33% than that of control (83%. Plants height was not significantly affected by endophytic bacterial treatments. Based on 16S rRNA sequence, BC4 isolate had 97% similarity with Staphylococcus epidermidis (accession number EU834240.1, while isolate BL10 had 98% similarity with Bacillus amyloliquefaciens strain JK-SD002 (accession number AB547229.1.

  14. Effect of Fertilization on Tomato Bacterial Wilt Biocontrolling and Soil Health Restoration Using FAME Analysis

    Institute of Scientific and Technical Information of China (English)

    CAI Yan-fei; ZHAO Su-qing; LIAO Zong-wen; HE Cheng-xin; ZHUANG Xue-ying

    2003-01-01

    The effect of applying biological organic fertilizer (BOF) on bacterial wilt incidence of tomatoand soil microbial community under continuous cropping was studied. The results showed that all the tomatoeswere infected by bacterial wilt in the control. The infection rates of tomatoes in the treatments with un-com-posted BOF and decomposed BOF were 55 and 50% respectively. Fatty acid methyl esters (FAME) analysisindicated soil microbial community changed sensitively after applying BOF. Soil FAME total content, relativefungi content and ratio of fungi to bacteria were significantly increased in both BOF treatments. The soil odd-number fatty acid proportion changed after applying BOF, aC15: 0, iC17 . 0 decreased, while cyC17 . 0 in-creased in soil odd-number fatty acid proportion. BOF application would strengthen soil health and diseasesuppression. The content of C16: 111c in soil microbial community was obviously increased after decomposedBOF application. It indicated that the growth of AM fungi could be enhanced with decomposed BOF applica-tion. FAME microbial biomarkers could be used for an indicator of soil health and disease suppression. Odd-number fatty acid proportion was a sensitive indicator of the effect of applying un-composted and decomposedBOF respectively on soil health regulating.

  15. DEVELOPMENT OF ANTIBODY TO RALSTONIA SOLANACEARUM AND ITS APPLICATION FOR DETECTION OF BACTERIAL WILT

    Directory of Open Access Journals (Sweden)

    YADI SURYADI

    2009-01-01

    Full Text Available The serological assay for the detection of bacterial wilt caused by Ralstonia solanacearum (RSwas able to provide information regarding the presence of the pathogen in plant materials. Theresearch is was aimed to develop polyclonal antibody (PAb for RS detection. Bacterial wholecells of RS isolates mixed with glutaraldehyde were used to immunize New Zealand femalewhite rabbit. The titre of antibody in culture supernatant was 1: 1024. The PAb developed froma ground nut RS isolates reacted with infected plant samples from various locations. It was ableto detect RS antigen of crude extract and pure cultures from tomato and potato plant samples4-5using dot blot ELISA; however, the minimum detectable concentration of RS antigen was 10cells/ml. The PAb obtained in this study is sensitive enough to detect RS isolates in routineserological assay

  16. EFFECTIVENESS OF CLOSTRIDIUM ISOLATES ON AEROPONICALLY CULTIVATED POTATO TO PROTECT AGAINST RALSTONIA SOLANACEARUM (BACTERIAL WILT) AND PCR DETECTION ON LATEN INFECTION ON TUBERS.

    OpenAIRE

    Baharuddin.

    2012-01-01

    Aeroponic technology was used to optimize production of potato mini tubers. Several adventage was the production 5-10 times higher and tuber size was bigger than covensional methods, but unfortunatelly some times yield loss was present caused by bacterial wilt Ralstonia solanacearum. Although not all of plants were died and some of plants still produce tubers, but laten infection of bacterial wilt was occured. Early observation on microbes diversity on healthy and on infected plants ...

  17. Murcha bacteriana no estado do Amazonas, Brasil Bacterial wilt in Amazonas State, Brazil

    Directory of Open Access Journals (Sweden)

    Rosalee A. Coelho Netto

    2004-02-01

    Full Text Available Durante 1998 e 2000, a incidência de murcha bacteriana causada por Ralstonia solanacearum foi registrada em 25 municípios do estado do Amazonas. A bactéria foi encontrada nas seguintes espécies vegetais: Capsicum annuum, C. chinense, C. frutescens, Cucumis sativus, Heliconia sp., Lycopersicon esculentum, Melanthera discoidea, Moringa oleifera, Musa sp., Solanum melongena, S. gilo, e S. nigrum. Em tomateiros (Lycopersicon esculentum, a murcha bacteriana estava presente em todos os plantios. Em bananeiras (Musa spp., a incidência do Moko foi menor nas várzeas dos rios Madeira e Negro do que nas dos rios Solimões e Amazonas. Caracterizaram-se 320 isolados de R. solanacearum, obtidos no levantamento, com relação a raça e a biovar. A biovar 1 predominou em todos os hospedeiros, com exceção de C. annuum e C. chinense, onde estirpes da biovar 3 foram maioria. Apenas 7,8% das estirpes foram da biovar N2. A sensibilidade de 56 estirpes da raça 1 a 23 bacteriocinas foi avaliada. As estirpes da biovar 3 apresentaram uma menor variabilidade, na sensibilidade a bacteriocinas do que as estirpes das biovares 1 e N2.A survey for bacterial wilt caused by Ralstonia solanacearum was conducted in 25 counties in the state of Amazonas during the years 1998 and 2000. Ralstonia solanacearum was found in the following species: Capsicum annuum, C. chinense, C. frutescens, Cucumis sativus, Heliconia sp., Lycopersicon esculentum, Melanthera discoidea, Moringa oleifera, Musa sp., Solanum melongena, S. gilo, and S. nigrum. In tomatoes (Lycopersicon esculentum, bacterial wilt was present in all fields. In banana (Musa spp., the incidence of Moko disease was lower in the flooded areas of the Madeira and Negro Rivers than in the Solimões and Amazonas Rivers. In this survey the race and biovar of 320 R. solanacearum isolates was determined. The biovar 1 strains predominate in almost all hosts. In C. annuum and C. chinense, however, biovar 3 was more common. Only 7

  18. Overexpression of the Eggplant (Solanum melongena) NAC Family Transcription Factor SmNAC Suppresses Resistance to Bacterial Wilt.

    Science.gov (United States)

    Na, Chen; Shuanghua, Wu; Jinglong, Fu; Bihao, Cao; Jianjun, Lei; Changming, Chen; Jin, Jiang

    2016-01-01

    Bacterial wilt (BW) is a serious disease that affects eggplant (Solanum melongena) production. Although resistance to this disease has been reported, the underlying mechanism is unknown. In this study, we identified a NAC family transcription factor (SmNAC) from eggplant and characterized its expression, its localization at the tissue and subcellular levels, and its role in BW resistance. To this end, transgenic eggplant lines were generated in which the expression of SmNAC was constitutively up regulated or suppressed using RNAi. The results indicated that overexpression of SmNAC decreases resistance to BW. Moreover, SmNAC overexpression resulted in the reduced accumulation of the plant immune signaling molecule salicylic acid (SA) and reduced expression of ICS1 (a gene that encode isochorismate synthase 1, which is involved in SA biosynthesis). We propose that reduced SA content results in increased bacterial wilt susceptibility in the transgenic lines. Our results provide important new insights into the regulatory mechanisms of bacterial wilt resistance in eggplant. PMID:27528282

  19. Microarray Analysis of the Transcriptome for Bacterial Wilt Resistance in Pepper (Capsicum annuum L.

    Directory of Open Access Journals (Sweden)

    Jihyun HWANG

    2011-11-01

    Full Text Available Ralstonia solanacearum causes one of the most common soil-borne vascular diseases of diverse plant species, including many solanaceous crops such as tomato and pepper. The resulting disease, bacterial wilt (BW, is devastating and difficult to control using conventional approaches. The aim of this study was to investigate the differentially expressed genes in pepper root systems in response to infection by R. solanacearum. DNA microarray (Capsicum annuum 135K Microarray v3.0 Gene Expression platform analyses were performed using a susceptible genotype, ‘Chilbok’, and a resistant genotype, ‘KC350’, at 3 time points (1, 3, and 6 days post inoculation. It has been identified 115 resistance-specific genes (R-response genes and 109 susceptibility-specific genes (S-response gene, which were up-regulated in 1 genotype, but down-regulated in the other genotype. Gene Ontology (GO analysis for functional categorization indicated that many R-response genes were related to genes that function in xyloglucan biosynthesis and cell wall organization, while S-response genes were involved in the response to stress and cell death. The expression of genes encoding xyloglucan endotransglycosylase/hydrolase (XTH and β-galactosidase were verified by real-time RT-PCR at an early time point of R. solanacearum infection. The results supported the idea that rapidly induced XTH expression in ‘KC350’ may play an important role in the restructuring and reinforcement of the cell wall and restrict bacterial movement in xylem vessels. In addition, induced expression of β-galactosidase in R. solanacearum-infected ‘Chilbok’ implied that degradation of the cell wall structure in vascular tissues by β-galactosidase might be an important factor facilitating R. solanacearum invasion of and movement in susceptible host plants.

  20. Water Extract from Spent Mushroom Substrate of Hericium erinaceus Suppresses Bacterial Wilt Disease of Tomato

    OpenAIRE

    Kwak, A Min; Min, Kyeong Jin; Lee, Sang Yeop; Kang, Hee Wan

    2015-01-01

    Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium caro...

  1. Evaluation of the gene encoding the enzyme βHPMEH for the bacterial wilt inhibition caused by Ralstonia solanacearum

    Directory of Open Access Journals (Sweden)

    Elizabeth Fernandez

    2015-10-01

    Full Text Available Ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease that attacks important agricultural crops such as potato, tomato, banana, among others, causing serious yield losses. Control of R. solanacearum is difficult because of its wide range of alternate hosts, its long survival in soil, its biological and genetic variation, the lack of natural resistance sources and the insufficiency of the appropriate chemical control measures. Quorum sensing is the term that describes the phenomenon whereby the accumulation of molecules allows bacteria to know the number of bacteria found in the environment (population density. R. solanacearum has a quorum sensing system for the regulation of the expression of virulence genes; the molecule 3-OH-PAME is the self-regulatory signal. The molecule ΒHPMEH hydrolyzes 3-OH-PAME nullifying the signal of virulence, and thus, the quorum sensing communication in R. solanacearum. In order to evaluate the βhpmeh gene we designed two vectors that express this gene under the control of two different promoters. Both vectors were verified by restriction analysis and sequencing. Agroinfiltration assays were used to analyze gene expression and the effect against R. solanacearum in potato (Solanum tuberosum leaves. The results of the transient expression experiments showed that the expression of gene βhpmeh caused a delay in the appearance of symptoms of bacterial wilt and thus is a good candidate for whole genetic plant transformation.

  2. The effect of lactic acid bacterial starter culture and chemical additives on wilted rice straw silage.

    Science.gov (United States)

    Wang, Yan-Su; Shi, Wei; Huang, Lin-Ting; Ding, Cheng-Long; Dai, Chuan-Chao

    2016-04-01

    Lactic acid bacteria (LAB) are suitable for rice straw silage fermentation, but have been studied rarely, and rice straw as raw material for ensiling is difficult because of its disadvantages, such as low nutrition for microbial activities and low abundances of natural populations of LAB. So we investigated the effect of application of LAB and chemical additives on the fermentation quality and microbial community of wilted rice straw silage. Treatment with chemical additives increased the concentrations of crude protein (CP), water soluble carbohydrate (WSC), acetic acid and lactic acid, reduced the concentrations of acid detergent fiber (ADF) and neutral detergent fiber (NDF), but did not effectively inhibit the growth of spoilage organisms. Inoculation with LABs did not improve the nutritional value of the silage because of poor growth of LABs in wilted rice straw. Inoculation with LAB and addition of chemical materials improved the quality of silage similar to the effects of addition of chemical materials alone. Growth of aerobic and facultatively anaerobic bacteria was inhibited by this mixed treatment and the LAB gradually dominated the microbial community. In summary, the fermentation quality of wilted rice straw silage had improved by addition of LAB and chemical materials. PMID:26429595

  3. Effect of Seed Treatment by Cold Plasma on the Resistance of Tomato to Ralstonia solanacearum (Bacterial Wilt)

    Science.gov (United States)

    Jiang, Jiafeng; Lu, Yufang; Li, Jiangang; Li, Ling; He, Xin; Shao, Hanliang; Dong, Yuanhua

    2014-01-01

    This study investigated the effect of cold plasma seed treatment on tomato bacterial wilt, caused by Ralstonia solanacearum (R. solanacearum), and the regulation of resistance mechanisms. The effect of cold plasma of 80W on seed germination, plant growth, nutrient uptake, disease severity, hydrogen peroxide (H2O2) concentration and activities of peroxidase (POD; EC 1.11.1.7), polyphenol oxidase (PPO; EC 1.10.3.2) and phenylalanine ammonia lyase (PAL; EC 4.3.1.5) were examined in tomato plants. Plasma treatment increased tomato resistance to R. solanacearum with an efficacy of 25.0%. Plasma treatment significantly increased both germination and plant growth in comparison with the control treatment, and plasma-treated plants absorbed more calcium and boron than the controls. In addition, H2O2 levels in treated plants rose faster and reached a higher peak, at 2.579 µM gFW−1, 140% greater than that of the control. Activities of POD (421.3 U gFW−1), PPO (508.8 U gFW−1) and PAL (707.3 U gFW−1) were also greater in the treated plants than in the controls (103.0 U gFW−1, 166.0 U gFW−1 and 309.4 U gFW−1, respectively). These results suggest that plasma treatment affects the regulation of plant growth, H2O2 concentration, and POD, PPO and PAL activity in tomato, resulting in an improved resistance to R. solanacearum. Consequently, cold plasma seed treatment has the potential to control tomato bacterial wilt caused by R. solanacearum. PMID:24840508

  4. Effect of seed treatment by cold plasma on the resistance of tomato to Ralstonia solanacearum (Bacterial Wilt.

    Directory of Open Access Journals (Sweden)

    Jiafeng Jiang

    Full Text Available This study investigated the effect of cold plasma seed treatment on tomato bacterial wilt, caused by Ralstonia solanacearum (R. solanacearum, and the regulation of resistance mechanisms. The effect of cold plasma of 80W on seed germination, plant growth, nutrient uptake, disease severity, hydrogen peroxide (H2O2 concentration and activities of peroxidase (POD; EC 1.11.1.7, polyphenol oxidase (PPO; EC 1.10.3.2 and phenylalanine ammonia lyase (PAL; EC 4.3.1.5 were examined in tomato plants. Plasma treatment increased tomato resistance to R. solanacearum with an efficacy of 25.0%. Plasma treatment significantly increased both germination and plant growth in comparison with the control treatment, and plasma-treated plants absorbed more calcium and boron than the controls. In addition, H2O2 levels in treated plants rose faster and reached a higher peak, at 2.579 µM gFW-1, 140% greater than that of the control. Activities of POD (421.3 U gFW-1, PPO (508.8 U gFW-1 and PAL (707.3 U gFW-1 were also greater in the treated plants than in the controls (103.0 U gFW-1, 166.0 U gFW-1 and 309.4 U gFW-1, respectively. These results suggest that plasma treatment affects the regulation of plant growth, H2O2 concentration, and POD, PPO and PAL activity in tomato, resulting in an improved resistance to R. solanacearum. Consequently, cold plasma seed treatment has the potential to control tomato bacterial wilt caused by R. solanacearum.

  5. Transcriptional responses of Italian ryegrass during interaction with Xanthomonas translucens pv. graminis reveal novel candidate genes for bacterial wilt resistance

    DEFF Research Database (Denmark)

    Wichmann, Fabienne; Asp, Torben; Widmer, Franko; Kölliker, Roland

    2011-01-01

    Xanthomonas translucens pv. graminis (Xtg) causes bacterial wilt, a severe disease of forage grasses such as Italian ryegrass (Lolium multiflorum Lam.). In order to gain a more detailed understanding of the genetic control of resistance mechanisms and to provide prerequisites for marker assisted...... selection, the partial transcriptomes of two Italian ryegrass genotypes, one resistant and one susceptible to bacterial wilt were compared at four time points after Xtg infection. A cDNA microarray developed from a perennial ryegrass (Lolium perenne) expressed sequence tag set consisting of 9,990 unique...... genes was used for transcriptome analysis in Italian ryegrass. An average of 4,487 (45%) of the perennial ryegrass sequences spotted on the cDNA microarray were detected by cross-hybridisation to Italian ryegrass. Transcriptome analyses of the resistant versus the susceptible genotype revealed...

  6. The uptake, distribution and translocation of 86Rb in alfalfa plants susceptible and resistant to the bacterial wilt and the effect of Corynebacterium insidiosum upon these processes

    International Nuclear Information System (INIS)

    Alfalfa (Medicago sativa L.) plants susceptible (S) and resistant (R) to bacterial wilt were fed via roots with a nutrient solution labelled with 86Rb+, at different times after inoculation with Corynebacterium insidiosum (McCull.) H.L. Jens. The infection did not affect 86Rb+ uptake per plant in the course of a 14-day-period following inoculation; however, it affected its distribution differently in the S- and the R-plants. 86Rb+ uptake significantly decreased due to the infection in the S-plants on the day 49 after inoculation (a 4-h-exposure to 86Rb+), with the ions more slowly translocated to the shoots in diseased S-plants than in diseased R-plants. Likely factors causing these effects and their relationship to alfalfa resistance to bacterial wilt are discussed. (author)

  7. Identification of an Endophytic Antifungal Bacterial Strain Isolated from the Rubber Tree and Its Application in the Biological Control of Banana Fusarium Wilt

    OpenAIRE

    Deguan Tan; Lili Fu; Bingyin Han; Xuepiao Sun; Peng Zheng; Jiaming Zhang

    2015-01-01

    Banana Fusarium wilt (also known as Panama disease) is one of the most disastrous plant diseases. Effective control methods are still under exploring. The endophytic bacterial strain ITBB B5-1 was isolated from the rubber tree, and identified as Serratia marcescens by morphological, biochemical, and phylogenetic analyses. This strain exhibited a high potential for biological control against the banana Fusarium disease. Visual agar plate assay showed that ITBB B5-1 restricted the mycelial grow...

  8. Structure-Activity Relationships of Antimicrobial Gallic Acid Derivatives from Pomegranate and Acacia Fruit Extracts against Potato Bacterial Wilt Pathogen.

    Science.gov (United States)

    Farag, Mohamed A; Al-Mahdy, Dalia A; Salah El Dine, Riham; Fahmy, Sherifa; Yassin, Aymen; Porzel, Andrea; Brandt, Wolfgang

    2015-06-01

    Bacterial wilts of potato, tomato, pepper, and or eggplant caused by Ralstonia solanacearum are among the most serious plant diseases worldwide. In this study, the issue of developing bactericidal agents from natural sources against R. solanacearum derived from plant extracts was addressed. Extracts prepared from 25 plant species with antiseptic relevance in Egyptian folk medicine were screened for their antimicrobial properties against the potato pathogen R. solancearum by using the disc-zone inhibition assay and microtitre plate dilution method. Plants exhibiting notable antimicrobial activities against the tested pathogen include extracts from Acacia arabica and Punica granatum. Bioactivity-guided fractionation of A. arabica and P. granatum resulted in the isolation of bioactive compounds 3,5-dihydroxy-4-methoxybenzoic acid and gallic acid, in addition to epicatechin. All isolates displayed significant antimicrobial activities against R. solanacearum (MIC values 0.5-9 mg/ml), with 3,5-dihydroxy-4-methoxybenzoic acid being the most effective one with a MIC value of 0.47 mg/ml. We further performed a structure-activity relationship (SAR) study for the inhibition of R. solanacearum growth by ten natural, structurally related benzoic acids. PMID:26080741

  9. Transgenic banana plants expressing Xanthomonas wilt resistance genes revealed a stable non-target bacterial colonization structure.

    Science.gov (United States)

    Nimusiima, Jean; Köberl, Martina; Tumuhairwe, John Baptist; Kubiriba, Jerome; Staver, Charles; Berg, Gabriele

    2015-01-01

    Africa is among the continents where the battle over genetically modified crops is currently being played out. The impact of GM in Africa could potentially be very positive. In Uganda, researchers have developed transgenic banana lines resistant to banana Xanthomonas wilt. The transgenic lines expressing hrap and pflp can provide a timely solution to the pandemic. However, the impact of the transgenes expression on non-target microorganisms has not yet been investigated. To study this effect, transgenic and control lines were grown under field conditions and their associated microbiome was investigated by 16S rRNA gene profiling combining amplicon sequencing and molecular fingerprinting. Three years after sucker planting, no statistically significant differences between transgenic lines and their non-modified predecessors were detected for their associated bacterial communities. The overall gammaproteobacterial rhizosphere microbiome was highly dominated by Xanthomonadales, while Pseudomonadales and Enterobacteriales were accumulated in the pseudostem. Shannon indices revealed much higher diversity in the rhizosphere than in the pseudostem endosphere. However, the expression of the transgenes did not result in changes in the diversity of Gammaproteobacteria, the closest relatives of the target pathogen. In this field experiment, the expression of the resistance genes appears to have no consequences for non-target rhizobacteria and endophytes. PMID:26657016

  10. Relationship between resistance to Stewart's wilt and Goss's wilt in dent corn inbreds

    Science.gov (United States)

    Stewart's wilt, caused by Pantoea stewartii subsp. stewartii and Goss's wilt, caused by Clavibacter michiganensis ssp. nebraskensis (Cmn), are the two prominent bacterial leaf blight pathogens in maize in the US. Goss's wilt has become much more widespread in geographic range since 2008 and many pop...

  11. 姜瘟病研究进展和防治策略探讨%Study Progress and Prevention Strategy for Ginger Bacterial Wilt Disease

    Institute of Scientific and Technical Information of China (English)

    邱正明; 矫振彪; 郭凤领; 陈磊夫; 田延富; 胡燕; 吴金平

    2015-01-01

    Ginger bacterial wilt disease occurred frequently has become the bottleneck for restricting the development of ginger planting industry. The research progress of the symptoms, the pathogens, the pathogenic factors and the infection pathways was summarized. By screening and creating the resource for ginger of the highquality and disease resistance (tolerance), and we obtained resistance materials of bacterial wilt disease. Building new bioactive substances or new genes against pathogen of the bacterial wilt disease by the metagenomic libraryconstructed of the rhizosphere soil microbial of ginger, so we can obtain the new resources and strategies forecological prevention thebacterial wilt disease. By studying the change of soil microbial community for ginger rhizosphere by the theory of the rhizospheremicroecological balance, we can reduce or eliminate thebacterial wilt disease of ginger by the modified for the soil biological activity.%生姜姜瘟病频发已成为制约生姜种植业发展的瓶颈。笔者分析了姜瘟病的发病症状、病原菌、致病环境因子以及侵染路径等方面的研究现状,提出通过筛选、创制“优质、抗(耐)病”的生姜资源,为生姜抗病育种提供新材料;同时,通过构建生姜根际土壤微生物宏基因组文库,挖掘抗姜瘟病病菌的新生物活性物质或新基因,在基因组水平上为姜瘟病的生态防控提供新资源。此外,笔者还利用根际微生态平衡理论,研究了生姜根际土壤微生物群落的变化,通过土壤生物活性的改良,消除或者减轻姜瘟病的危害。

  12. Disease interactions in a shared host plant: effects of pre-existing viral infection on cucurbit plant defense responses and resistance to bacterial wilt disease.

    Directory of Open Access Journals (Sweden)

    Lori R Shapiro

    Full Text Available Both biotic and abiotic stressors can elicit broad-spectrum plant resistance against subsequent pathogen challenges. However, we currently have little understanding of how such effects influence broader aspects of disease ecology and epidemiology in natural environments where plants interact with multiple antagonists simultaneously. In previous work, we have shown that healthy wild gourd plants (Cucurbita pepo ssp. texana contract a fatal bacterial wilt infection (caused by Erwinia tracheiphila at significantly higher rates than plants infected with Zucchini yellow mosaic virus (ZYMV. We recently reported evidence that this pattern is explained, at least in part, by reduced visitation of ZYMV-infected plants by the cucumber beetle vectors of E. tracheiphila. Here we examine whether ZYMV-infection may also directly elicit plant resistance to subsequent E. tracheiphila infection. In laboratory studies, we assayed the induction of key phytohormones (SA and JA in single and mixed infections of these pathogens, as well as in response to the feeding of A. vittatum cucumber beetles on healthy and infected plants. We also tracked the incidence and progression of wilt disease symptoms in plants with prior ZYMV infections. Our results indicate that ZYMV-infection slightly delays the progression of wilt symptoms, but does not significantly reduce E. tracheiphila infection success. This observation supports the hypothesis that reduced rates of wilt disease in ZYMV-infected plants reflect reduced visitation by beetle vectors. We also documented consistently strong SA responses to ZYMV infection, but limited responses to E. tracheiphila in the absence of ZYMV, suggesting that the latter pathogen may effectively evade or suppress plant defenses, although we observed no evidence of antagonistic cross-talk between SA and JA signaling pathways. We did, however, document effects of E. tracheiphila on induced responses to herbivory that may influence host

  13. Meta-analysis Reveals That the Genus Pseudomonas Can Be a Better Choice of Biological Control Agent against Bacterial Wilt Disease Caused by Ralstonia solanacearum.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Subramanian, Dharaneedharan; Yoon, Ee; Kwon, Taehoon; Chun, Se-Chul

    2016-06-01

    Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from -2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression. PMID:27298597

  14. Transgenic banana plants expressing Xanthomonas wilt resistance genes revealed a stable non-target bacterial colonization structure

    OpenAIRE

    Jean Nimusiima; Martina Köberl; John Baptist Tumuhairwe; Jerome Kubiriba; Charles Staver; Gabriele Berg

    2015-01-01

    Africa is among the continents where the battle over genetically modified crops is currently being played out. The impact of GM in Africa could potentially be very positive. In Uganda, researchers have developed transgenic banana lines resistant to banana Xanthomonas wilt. The transgenic lines expressing hrap and pflp can provide a timely solution to the pandemic. However, the impact of the transgenes expression on non-target microorganisms has not yet been investigated. To study this effect,...

  15. 广藿香抗青枯病鉴定方法的研究%Study on Bacterial-wilt-resistance Identification Methods for Pogostemon cablin (Blanco) Benth.

    Institute of Scientific and Technical Information of China (English)

    贺红; 温雁鹰; 许仕仰; 梁志毅

    2011-01-01

    Objective To investigate the optimal concentration and inoculation procedure of crude toxin from Ralstonia solanacearum, and to establish the identification method for bacterial wilt resistance of Pogostemon cablin (Blanco) Benth. seedling, so as to lay the foundation for resistance breeding of Pogostemon cablin (Blanco)Benth.. Methods The growth curve of Ralstonia solanacearum was determined. And then we studied the effect of seedling age, crude toxin concentrations and inoculation ways for the crude toxin on the pathogenicity of Pogostemon cablin (Blanco) Benth.. Results The growth of Ralstonia solanacearum presented as the S-shaped curve, the highest concentration being 12. 46 × l08 cfu/mL. The seedling of Pogostemon cablin (Blanco) Benth. aged 100 days was optimal for the identification of bacterial wilt resistance. In the crude toxin concentration range of 0. 4 ×108 ~ 0. 6 × 108 cfu/mL, the inoculated plant showed a moderately advanced progress of bacterial wilt, which was suitable for the resistance identification. Having the advantage of shortening the experiment period, the rootsubmerging method was recommended for the resistance identification of Pogostemon cablin (Blanco) Benth..Conclusion The indoor identification method for Pogostemon cablin (Blanco) Benth. resistance to bacterial wilt has been established preliminarily.%[目的]对广藿香幼苗接种青枯茵粗毒素,观察其感病状况,建立广藿香苗期抗性鉴定方法,为广藿香抗病育种奠定基础.[方法]测定不同培养时间的青枯茵菌液浓度,绘制青枯菌的生长曲线;分别设置不同广藿香苗龄、不同浓度青枯菌制备粗毒素及不同接种方法等试验,探讨影响致病性的因素.[结果]青枯茵的生长曲线呈"S"型,青枯茵菌液浓度在稳定期最高可达12.46×108cfu/mL.对于广藿香抗青枯病的苗期鉴定,以100d左右苗龄的植株较适宜;在0.4×108~0.6×108cfu/mL浓度范围内,接种植株表现渐进的发病过

  16. Development of variable number of tandem repeats typing schemes for Ralstonia solanacearum, the agent of bacterial wilt, banana Moko disease and potato brown rot.

    Science.gov (United States)

    N'guessan, Carine Aya; Brisse, Sylvain; Le Roux-Nio, Anne-Claire; Poussier, Stéphane; Koné, Daouda; Wicker, Emmanuel

    2013-03-01

    Ralstonia solanacearum is an important soil borne bacterial plant pathogen causing bacterial wilt on many important crops. To better monitor epidemics, efficient tools that can identify and discriminate populations are needed. In this study, we assessed variable number of tandem repeats (VNTR) genotyping as a new tool for epidemiological surveillance of R. solanacearum phylotypes, and more specifically for the monitoring of the monomorphic ecotypes "Moko" (banana-pathogenic) and "brown rot" (potato-pathogenic under cool conditions). Screening of six R. solanacearum genome sequences lead to select 36 VNTR loci that were preliminarily amplified on 24 strains. From this step, 26 single-locus primer pairs were multiplexed, and applied to a worldwide collection of 337 strains encompassing the whole phylogenetic diversity, with revelation on a capillary-electrophoresis genotype. Four loci were monomorphic within all phylotypes and were not retained; the other loci were highly polymorphic but displayed a clear phylotype-specificity. Phylotype-specific MLVA schemes were thus defined, based on 13 loci for phylotype I, 12 loci for phylotype II, 11 loci for phylotype III and 6 for phylotype IV. MLVA typing was significantly more discriminative than egl-based sequevar typing, particularly on monomorphic "brown rot" ecotype (phylotype IIB/sequevar 1) and "Moko disease" clade 4 (Phylotype IIB/sequevar 4). Our results raise promising prospects for studies of population genetic structures and epidemiological monitoring. PMID:23376194

  17. Molecular characterizations of microbial antagonists and development of bioformulations for management of bacterial wilt of Naga Chilli (Capsicum chinens Jacq. in Assam

    Directory of Open Access Journals (Sweden)

    Lohit Kataki, Kuldeep Talukdar

    2015-04-01

    Full Text Available Aggressive strains of five different saprophytic antagonists Trichoderma parareesei TPJ-S-1, Trichoderma viride TVJ-S-1, Paecilomyces variotii Isolate-1, Bacillus thuringiensis BTJ-S-1 and Citrobacter farmeri CTJ-S-1 and their consortial formulations were evaluated during 2012-14, for their effectiveness in management of bacterial wilt disease (c. o. Ralstonia solanacearum of Naga chilli (Capsicum chinens Jacq.. The molecular characterization of selected antagonists was undertaken to determine their distinctiveness from their close relatives through sequencing of the 18S & 28S region of ribosomal DNA in case of fungal antagonists and 16S region in case of bacterial antagonists along with its phylogenetic analysis. The antagonistic potential of the five microbes were tested in vitro singly and in consortia against R. solanacearum adopting dual culture method. Altogether 31 treatment combinations were compared; the inhibition zones (mm and percent inhibitions were recorded and analyzed. The highest inhibition (91.47% against R. solanacearum was recorded in consortia of T. parareesei, T. viride and B. thuringiensis followed by the consortia of T. parareesei, T. viride, P. variotii, B. thuringiensis and C. farmeri (82.22%. Quantitative aspect of population dynamics of selected antagonists in three different substrate carrier viz. vermicompost, talcum powder (TP and mustard oil cake (MOC were compared to evaluate their shelf – life at different days of storage

  18. Effects of volatile organic compounds produced by Bacillus amyloliquefaciens on the growth and virulence traits of tomato bacterial wilt pathogen Ralstonia solanacearum.

    Science.gov (United States)

    Raza, Waseem; Wang, Jichen; Wu, Yuncheng; Ling, Ning; Wei, Zhong; Huang, Qiwei; Shen, Qirong

    2016-09-01

    The production of volatile organic compounds (VOCs) by microbes is an important characteristic for their selection as biocontrol agents against plant pathogens. In this study, we identified the VOCs produced by the biocontrol strain Bacillus amyloliquefaciens T-5 and evaluated their impact on the growth and virulence traits of tomato bacterial wilt pathogen Ralstonia solanacearum. The results showed that the VOCs of strain T-5 significantly inhibited the growth of R. solanacearum in agar medium and in soil. In addition, VOCs significantly inhibited the motility traits, root colonization, biofilm formation, and production of antioxidant enzymes and exopolysaccharides by R. solanacearum. However, no effect of VOCs on the production of hydrolytic enzymes by R. solanacearum was observed. The strain T-5 produced VOCs, including benzenes, ketones, aldehydes, alkanes, acids, and one furan and naphthalene compound; among those, 13 VOCs showed 1-10 % antibacterial activity against R. solanacearum in their produced amounts by T-5; however, the consortium of all VOCs produced on agar medium, in sterilized soil, and in natural soil showed 75, 62, and 85 % growth inhibition of R. solanacearum, respectively. The real-time PCR analysis further confirmed the results when the expression of different virulence- and metabolism-related genes in R. solanacearum cells was decreased after exposure to the VOCs of strain T-5. The results of this study clearly revealed the significance of VOCs in the control of plant pathogens. This information would help to better comprehend the microbial interactions mediated by VOCs in nature and to develop safer strategies to control plant disease. PMID:27183998

  19. Controle biológico da murcha bacteriana do tomateiro, por Pseudomonas spp. fluorescentes Biological control of bacterial wilt of tomato by fluorescent Pseudomonas spp

    Directory of Open Access Journals (Sweden)

    Ana Rosa Peixoto

    1997-03-01

    Full Text Available Esta revisão bibliográfica teve como objetivo avaliar o potencial de antagonismo de espécies de Pseudomonas fluorescentes a Pseudomonas solanacearum, agente causal da murcha bacteriana do tomateiro. Devido a dificuldade encontrada nas estratégias utilizadas para o controle da Murcha Bacteriana por meio de métodos convencionais, alguns outros tem sido estudados, como o uso de microrganismos benéficos. As rizobactérias vem proporcionando solução viável a algumas doenças consideradas de difícil manejo. Dentre os mecanismos que tem sido sugeridos para o controle microbiano de patógenos de plantas, através do uso de rizobactérias fluorescentes, citamse produção de antibióticos, bactericinas, enzimas titicas, competição por espaço e nutrientes. Possuem uma alta capacidade de colonização e sobrevivência no hospedeiro, falares que são importantes no estabelecimento e introdução de microrganismos na rizosfera. Estas bactérias podem também incitar um aumento no desenvolvimento e na produção do hospedeiro, sendo denominadas de rizobactérias promotoras de crescimento de plantas.This literature review has the objetive of evaluating the antagonism potential of species of florescem Pseudomonas to Pseudomonas solanacearum which is the causal agent of bacterial wilt on the tomato crop. Due to serious limitation in the ejficiency of conventional methods of contrai, other strategies have been siudied, such as the use o/beneficiai microrganisms. Rhizobacteria have shown to be a viable alternative in the contrai of some diseases of difficult managmenl. Among the mechanisms which have been suggestedfor microbian control of plantpathogens with fluorescent rhizobacteria, can be used antibiotic production, bacteriocin, uric emimes and competition for colonization and survival capacity on the host. The survival capacity is very important in the introduction and stablishment ofthe microrganisms in the rhizosphere. These bacteria can aiso

  20. Evaluation of tomato rootstocks and its use to control bacterial wilt diseaseAvaliação de porta-enxertos de tomateiro e o uso da enxertia no controle da murcha bacteriana

    Directory of Open Access Journals (Sweden)

    Francisco Ferraz Laranjeira

    2012-05-01

    Full Text Available Tomato plants are susceptible to bacterial wilting, which causes production losses varying from 10 to 100 %. A method for controlling this disease is the use of grafting on resistant rootstocks. This work had the objective of evaluating tomato genotypes for the resistance to Ralstonia solanacearum and the grafting technique as an alternative for the bacterial wilt control in the region of Recôncavo Baiano, Brazil. To evaluate the resistance to R. solanacearum, four local genotypes, collected in different regions of Bahia, the cv. Santa Clara as a susceptible treatment, and the Hawaii 7996 (H7996, as a resistant treatment were studied. For the evaluation of grafting method for control of bacterial wilt, the H7996 was used as rootstock, and the cvs. Santa Clara, Santa Cruz Kada, and Débora Plus were used as the scion plants. Both experiments were evaluated in an area infested with R. solanacearum, for a period of 65 days for the selection of the rootstocks and 45 days for the evaluation of the grafting method. Only the H7996 can be recommended as a R. solanacearum resistant rootstock. The other genotypes showed susceptibility to the pathogen. The grafting on the H7996 did not show incompatibility with the scion tomato cultivars tested and reached 100 % control of the bacterial wilt disease, for all treatments, suggesting that this method can be used as an alternative for the bacterial wilt control, allowing the production of susceptible tomato cultivars in areas infested with R. solanacearum A suscetibilidade do tomateiro à murcha bacteriana (Ralstonia solanacearum causa perdas que vão de 10 a 100 % na produção e uma das alternativas de controle que vem sendo utilizada é a enxertia com porta-enxerto resistente. Este trabalho teve o objetivo avaliar genótipos de tomateiro quanto à resistência a R. solanacearum e a enxertia como alternativa para o controle da murcha bacteriana do tomateiro na região do Recôncavo Baiano. Para avalia

  1. Fontes de resistência à murcha bacteriana em germoplasma de Capsicum spp. do estado do Amazonas Sources of resistance against bacterial wilt in Capsicum spp. germoplasm of the Amazonas state

    Directory of Open Access Journals (Sweden)

    Liane Cristine Rebouças Demosthenes

    2011-01-01

    Full Text Available A murcha bacteriana, causada por Ralstonia solanacearum, é uma das doenças mais importantes do gênero Capsicum no Brasil. No Amazonas, as condições de elevada temperatura e umidade favorecem o desenvolvimento da doença. O objetivo deste trabalho foi avaliar a resistência à murcha bacteriana de germoplasma, selvagem e comercial, de Capsicum spp. Foram avaliados 22 acessos de Capsicum em casa de vegetação. A inoculação foi feita mediante ferimento das raízes, seguido de adição no solo, ao redor das plantas, de suspensão bacteriana na concentração de 10(8 ufc mL-1. A avaliação foi feita diariamente a partir do quarto dia após a inoculação, em função desenvolvimento dos sintomas. A partir das médias de progresso dos sintomas foi construída a área abaixo da curva de progresso da doença (AACPD, e os dados submetidos ao teste de Scott-Knott ao nível de 5% de probabilidade, utilizando o programa estatístico SAEG 9.1. Foram selecionados os acessos 30, 20 e 17, da espécie C. chinense, como resistentes à murcha bacteriana para ensaios futuros em programas de melhoramento genético.The bacterial wilt caused by Ralstonia solanacearum is one of the most important in the genus Capsicum in Brazil. In the state of Amazonas, high temperatures and humidity favor the development of the disease. The objective of this work was to evaluate resistance in germoplasm of wild and commercial Capsicum spp. to bacterial wilt. Twenty two accesses of Capsicum spp. were evaluated in greenhouse conditions. The inoculation was made by means of wounds in the roots, followed by addition of bacterial suspension in the concentration of 10(8 ufc ml-1 in the soil, around the plants. Plant evaluation was made daily after the fourth day of the inoculation (DAI considering the symptoms progress. From the average progress of symptoms was constructed the area under the disease progress curve (AUDPC, and the data submitted to the Scott-Knott test at 5% of

  2. Tamanho do tubérculo-semente de batata não interfere na manifestação da murcha bacteriana Potato seed tuber size does not interfere with the incidence of potato bacterial wilt

    Directory of Open Access Journals (Sweden)

    Carlos A Lopes

    2011-06-01

    Full Text Available A batata-semente é comercializada no Brasil em diferentes tamanhos, conforme determinação do MAPA, variando do tipo 0 (zero, com tubérculos acima de 60 mm, até o tipo V, com tubérculos menores que 23 mm. Neste trabalho, foi avaliado o efeito do tamanho do tubérculo da batata-semente na manifestação da murcha bacteriana nas cultivares Agata, BRS Ana, Asterix e Bintje, em campo naturalmente infestado com Ralstonia solanacearum, em Brasília-DF. Foram usados tubérculos pequenos, médios e grandes, com aproximadamente 30, 50 e 90 mm em média, tamanhos correspondentes respectivamente aos tipos IV, II e 0 das normas do MAPA. Diferenças significativas quanto à incidência da doença foram encontradas entre cultivares: BRS Ana e Asterix não diferiram entre si e foram mais resistentes que Agata e Bintje que, por sua vez, tampouco diferiram entre si. As diferenças entre tamanhos de tubérculos e as interações entre cultivar e tamanho de tubérculos não foram significativas. Portanto concluiu-se que o tamanho de tubérculos dentro dos limites avaliados neste trabalho, não interferiu na manifestação da doença em testes de avaliação para resistência à murcha bacteriana.Potato seed tubers in Brazil are commercialized in different sizes as determined by the Ministry of Agriculture, Livestock and Food Supply. The sizes are classified in types, which vary from type 0 (zero, tubers above 60 mm, up to type V, tubers below 23 mm. In this work, we evaluated the influence of seed tuber size on the incidence of bacterial wilt on cultivars Agata, BRS Ana, Asterix, and Bintje, grown in a field naturally infested with Ralstonia solanacearum, in Brasilia, Brazil. We used small, medium and large tubers, measuring in average 30, 50 and 90 mm, which correspond respectively to types IV, II and 0 according to the Brazilian legislation. Significant differences in bacterial wilt incidences were detected among cultivars: BRS Ana and Asterix did not

  3. Effect of Integrated Use of Inorganic Fertilizer and Organic Manures on Bacterial Wilt Incidence (BWI)and Tuber Yield in Potato Production Systems on Hill Slopes of Central Kenya

    Institute of Scientific and Technical Information of China (English)

    Linus; M. M. Muriithi; Irungu; J. W

    2004-01-01

    Bacterial wilt (BW) caused by Ralstonia solanacearum is one of the most damaging diseases of potato (Solanum tuberosum L.) in Kenya and worldwide. In Kenya, potato tuber yield losses due to BW infection are estimated at 50 ~ 100%. Low soil fertility is also one of the most important constraints limiting potato production in central Kenya highlands. Farmers tackle this problem through use of inorganic fertilisers and organic manures, both of which amend the soil environment to influence bacterial wilt development.Undecomposed organic manures can also introduce the pathogen into a clean field. Between short rains 1999 and 2000, 10 on-farm extension-researcherfarmer-designed and farmer-managed trials were done at Kianjuki catchment in Embu District. The objective was to use farmers' participatory research approach and select the most suitable organic and inorganic fertiliser combination(s) with lowest BWI and acceptable usable tuber yields, and also to demonstrate use of some components of integrated disease management methods in reduction of disease incidence and spread. Seven treatments were proposed, presented to the farmers for discussion and the most relevant four were selected for evaluation.during the short rains 1999 and long rains 2000. BWI didn't result in significant differences between treatments but the tuber yields were significantly different in short rains of 1999 and 2000. During short rains 2000, both BWI and tuber yields and unusable tubers differed significantly between treatments. The results confirmed that welldecomposed manures or manures from pathogen-free areas can be used in combination with inorganic fertilisers to improve soil fertility and potato tuber yields in smallholder farms without influencing BWI.Use of certified seed tubers in pathogen free field and following recommended field sanitation measures resulted in apparently bacterial wilt free crop.Considering the high cost of inorganic fertiliser and its negative effects on the

  4. Control of tomato bacterial wilt through the incorporation of aerial part of pigeon pea and crotalaria to soil Controle da murcha bacteriana do tomateiro pela incorporação da parte aérea de guandu e crotalária no solo

    OpenAIRE

    Suane C. Cardoso; Ana Cristina F. Soares; Alexsandro dos S. Brito; Francisco F. Laranjeira; Carlos Alberto S. Ledo; Andiale P. dos Santos

    2006-01-01

    The use of organic matter that improves the physical, chemical and biological soil properties has been studied as an inducer of suppressiveness to soilborne plant pathogens. The objective of this work was to evaluate the effect of different sources and concentrations of organic matter on tomato bacterial wilt control. Two commercially available organic composts and freshly cut aerial parts of pigeon pea (Cajanus cajan) and crotalaria (Crotalaria juncea) were incorporated, in concentrations of...

  5. 土壤调理剂及复合微生物菌剂防治烟草青枯病盆栽试验%Pot Experiment of Prevention and Cure of Tobacco Bacterial Wilt with Soil Conditioner and Complex Microbial Agent

    Institute of Scientific and Technical Information of China (English)

    吕锦津; 马柱文; 谢锐鸿; 李淑玲

    2014-01-01

    通过盆栽试验研究了土壤调理剂及复合微生物菌剂对防治烟草青枯病的效果,并与PPF促生真菌试验效果进行了对比。试验结果表明,复合微生物菌剂和土壤调理剂对烟草青枯病均有较好的防治效果,其中复合微生物菌剂在促进烟株生长和防治烟草青枯病方面表现更好。%A pot experiment is carried out to study the effect of soil conditioner and complex microbial agent to control tobacco bacterial wilt, and comparison is made with the experiment effect of PPF growth promoting fungi.The experimental results show that both complex microbial agent and soil conditioner have good effect on prevention and cure of tobacco bacterial wilt, among them, complex microbial agent performs better at promoting growth of tobacco plant and control of tobacco bacterial wilt.

  6. A unique DNA repair and recombination gene (recN) sequence for identification and intraspecific molecular typing of bacterial wilt pathogen Ralstonia solanacearum and its comparative analysis with ribosomal DNA sequences

    Indian Academy of Sciences (India)

    Aundy Kumar; Thekkan Puthiyaveedu Prameela; Rajamma Suseelabhai

    2013-06-01

    Ribosomal gene sequences are a popular choice for identification of bacterial species and, often, for making phylogenetic interpretations. Although very popular, the sequences of 16S rDNA and 16-23S intergenic sequences often fail to differentiate closely related species of bacteria. The availability of complete genome sequences of bacteria, in the recent years, has accelerated the search for new genome targets for phylogenetic interpretations. The recently published full genome data of nine strains of R. solanacearum, which causes bacterial wilt of crop plants, has provided enormous genomic choices for phylogenetic analysis in this globally important plant pathogen. We have compared a gene candidate recN, which codes for DNA repair and recombination function, with 16S rDNA/16-23S intergenic ribosomal gene sequences for identification and intraspecific phylogenetic interpretations in R. solanacearum. recN gene sequence analysis of R. solanacearum revealed subgroups within phylotypes (or newly proposed species within plant pathogenic genus, Ralstonia), indicating its usefulness for intraspecific genotyping. The taxonomic discriminatory power of recN gene sequence was found to be superior to ribosomal DNA sequences. In all, the recN-sequence-based phylogenetic tree generated with the Bayesian model depicted 21 haplotypes against 15 and 13 haplotypes obtained with 16S rDNA and 16-23S rDNA intergenic sequences, respectively. Besides this, we have observed high percentage of polymorphic sites (S 23.04%), high rate of mutations (Eta 276) and high codon bias index (CBI 0.60), which makes the recN an ideal gene candidate for intraspecific molecular typing of this important plant pathogen.

  7. Effects of three composts on growth and bacterial wilt of tomato%三种堆肥对番茄生长及青枯病防治效果的影响

    Institute of Scientific and Technical Information of China (English)

    张建华; 郭玉双; 田光明; 张君; 姚静华

    2012-01-01

    合理施用堆肥能够有效地改善植物的生长条件和土壤的生态环境,从而提高植物对病害的抗性。通过盆栽试验,研究了药渣、 污泥和猪粪三种堆肥以不同比例与泥炭混合对番茄植株生长和番茄青枯病防治的影响。结果表明: 三种不同堆肥均能促进番茄植株生长,其中猪粪堆肥对番茄生长的促进效果最显著,当泥炭与猪粪的混合比例为3∶1时效果最好,当收获番茄植株时,其鲜重和干重较泥炭基础基质处理分别提高了29.8%和41.2%,污泥堆肥次之,药渣堆肥最差; 三种不同堆肥都能抑制青枯病的发生,药渣堆肥对番茄青枯病的抑制效果最明显,当泥炭与药渣的混合比例为4∶1时效果最好,在番茄植株移栽33d 时,其病情指数较泥炭基础基质降低了66.7%,污泥堆肥次之,猪粪堆肥最差。添加不同堆肥使得盆栽基质的理化性质、 酶活性和可培养微生物的数量发生了不同的变化,推测可能是上述因素的变化使其对番茄的生长和青枯病的防治效果产生了明显的差异。%Bacterial wilt of tomato caused by soil-borne pathogen Pseudomonas solanacearum is one of the major diseases in the tomato production both in China and in the world. The addition of compost to soil improves soil ecological environment and favors plant development, thereby strengthens plant resistance to pathogen, especially to soilborne plant pathogens. A greenhouse experiment was carried out to test the effects of the additions of different composts to peat on tomato plant growth and the suppression on the disease. The results show that different composts have different effects on tomato growth, and the pig manure compost has significantly effect for tomato growth. When the mixed volume ratio of the peat and pig manure compost is 3:1, the effect is the best, and compared to the control, the fresh weight and dry weight of the plants are increased

  8. Fusarium Wilt of Banana.

    Science.gov (United States)

    Ploetz, Randy C

    2015-12-01

    Banana (Musa spp.) is one of the world's most important fruits. In 2011, 145 million metric tons, worth an estimated $44 billion, were produced in over 130 countries. Fusarium wilt (also known as Panama disease) is one of the most destructive diseases of this crop. It devastated the 'Gros Michel'-based export trades before the mid-1900s, and threatens the Cavendish cultivars that were used to replace it; in total, the latter cultivars are now responsible for approximately 45% of all production. An overview of the disease and its causal agent, Fusarium oxysporum f. sp. cubense, is presented below. Despite a substantial positive literature on biological, chemical, or cultural measures, management is largely restricted to excluding F. oxysporum f. sp. cubense from noninfested areas and using resistant cultivars where the pathogen has established. Resistance to Fusarium wilt is poor in several breeding targets, including important dessert and cooking cultivars. Better resistance to this and other diseases is needed. The history and impact of Fusarium wilt is summarized with an emphasis on tropical race 4 (TR4), a 'Cavendish'-killing variant of the pathogen that has spread dramatically in the Eastern Hemisphere. PMID:26057187

  9. Fusarium wilt in seedless watermelons

    Science.gov (United States)

    Fusarium wilt of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai], caused by Fusarium oxysporum f. sp. niveum (E.F. Sm.) Snyd. & Hans., was first reported in the United States in 1894. Historically, Fusarium wilt has been the greatest yield-limiting disease of watermelon worldwide. The stat...

  10. Efeito da solarização e biofumigação na incidência da murcha bacteriana em tomateiro no campo Effect of soil solarization and biofumigation on tomato bacterial wilt incidence

    Directory of Open Access Journals (Sweden)

    Mírian J Baptista

    2006-06-01

    Full Text Available As doenças causadas por fitopatógenos do solo causam elevados prejuízos na maioria das espécies olerícolas. A solarização e a biofumigação são estratégias para controle destes organismos com potencial para aplicação em sistemas de manejo integrado. Neste trabalho, foi conduzido um experimento na Embrapa Hortaliças, Brasília - DF, para avaliar os efeitos da adição de resíduos orgânicos (biofumigação e da solarização na incidência natural da murcha-bacteriana do tomateiro, causada por Ralstonia solanacearum, nas características químicas do solo e na ocorrência de plantas invasoras. Os tratamentos avaliados foram adição de resíduos de brássicas (2% v/v, cama de frango (2% v/v, tratamento com brometo de metila e solo sem tratamento, todos solarizados ou não solarizados. Após a solarização, foram coletadas amostras de solo para determinação de suas características químicas e do banco de sementes de plantas invasoras. A solarização do solo provocou redução significativa no pH e nos teores de B e Zn. A adição de matéria orgânica ocasionou aumentos nos teores de Ca, K, e Na e reduziu os teores de Al. O banco de sementes de plantas invasoras, principalmente monocotiledôneas foi também reduzido significativamente. O tratamento com brometo de metila e a adição de cama de frango reduziram significativamente a incidência de murcha-bacteriana.Soilborne plant pathogens cause heavy losses to many vegetable crops. Solarization and organic residues amendments have been evaluated as disease control strategies with good perspectives for aplication in integrated management. Field experiments were carried out at Embrapa Hortaliças, Brasília-DF, to evaluate the effects of amending soil with organic residues (biofumigation and solarization on the incidence of bacterial wilt (Ralstonia solanacearum on tomato, on soil chemical characteristics, and weed control. Amendments with brassica residues (2%, chicken litter

  11. Identification of Corn Bacterial Wilt Pathogen by Nested-PCR Based on 16S rDNA%16S nested-PCR技术检测玉米细菌性枯萎病菌

    Institute of Scientific and Technical Information of China (English)

    吴琼; 陈枝楠; 范怀忠; 金显忠

    2005-01-01

    玉米细菌性枯萎病是玉米上的重要种传病害,病原菌为Pantoea stewartii subsp.stewartii.本研究设计了16S通用引物,扩增该病菌及其近似种的16S rDNA,通过序列测定和分析,针对该病菌设计了特异性引物,采用nested-PCR技术,能够准确地区别该病菌及其近似种,检测的灵敏度在DNA水平上达到10-3pg级,检测活菌则达到2 cfu.检测人工污染的玉米种子时,不受种子提取液中其它物质的干扰,灵敏度依然达到2 cfu.%Pantoea stewartii subsp. stewartii is the seed-borne causative agent of bacterial wilt and leaf blight of sweet corn and maize. In this study, a specific 16S rDNA-based nested-PCR (nPCR) was developed to identify the bacterium from a range of closely related bacteria. This PCR assay was proved to be highly sensitive with the detection limit of 10 -3pg genomic DNA or 2 colony forming units (cfu). Moreover, this PCR assay successfully detected the target bacteria as few as 2 cfu when tested with artificially contaminated seeds, and the sensitivity was not affected by seed compounds.

  12. 马铃薯体细胞杂种后代青枯病抗性鉴定及分子标记检测%Evaluation of Resistance and Associated Molecular Markers of Bacterial Wilt of Potato Somatic Hybrid Offspring

    Institute of Scientific and Technical Information of China (English)

    李朋; 蔡兴奎; 陈琳; 柳俊

    2014-01-01

    马铃薯(Solanum tuberosum L.)青枯病是由茄科雷尔氏菌(Ralstonia solanacearum)引起的一种毁灭性的细菌性土传病害。马铃薯青枯病抗性资源主要存在于一些野生种中,体细胞杂交是创制马铃薯青枯病抗性资源的一种有效途径。本研究以具有对青枯病抗性的体细胞杂种与栽培种杂交产生的100个后代为材料,对其进行青枯病抗性评价,旨在筛选可供育种利用的青枯病抗性资源。青枯病抗性鉴定结果表明,在试管苗组培鉴定中100个杂交后代共有6个基因型表型抗青枯病,温室钵栽接种鉴定有8个基因型表现为抗病,在两种接种鉴定中均表现为抗病的有3个基因型(07SF.3-79、07SF.6-8和07SF.6-5)。选用本实验室前期筛选的与青枯病抗性相关的4对SSR标记引物(STI0051、STI0054、STI0056、STI0057),对100个基因型进行分子标记检测,结果显示,有3个标记(STI0051.180、STI0054.180、STI0056.205)可以明确鉴定抗感基因型,它们表现为抗病稳定的3个基因型的标记位点与抗病对照的带型一致,而在感病对照中缺失,与表型鉴定结果吻合,表明筛选的SSR标记可以用于具有S. chacoense遗传背景材料的青枯病抗性辅助选择。%Ralstonia solanacearum, the causal pathogen of potato (Solanum tuberosum L.) bacterial wilt, is soil-borne and destructive for potato production. Somatic hybridization between S. tuberosum and wild relatives is an effective way to obtain germplasm possessing resistance to R. solanacearum. Evaluation of resistance to R. solanacearum on 100 progenies derived from somatic hybridization between S. tuberosum and wild relatives were conducted in this study to screen for germplasms that possess resistance to R. solanacearum and are relevant to breeding. The results showed that six clones exhibited resistance to the pathogen in vitro inoculation and eight clones performed resistance to the pathogen by

  13. Control of Fusarium Wilt of Chili With Chitinolytic Bacteria

    Directory of Open Access Journals (Sweden)

    DWI SURYANTO

    2010-03-01

    Full Text Available Biological control of plant disease using antagonistic microorganism has been obtaining much attention and implemented for decades. One of the potential microorganisms used in this strategy is chitinolytic bacteria. Utilization of this bacteria ranges from cell life, enzymes, genes, or other metabolites. In this study, we examined the ability of chitinolytic bacteria as a biocontrol agent of Fusarium wilt of red chili (Capsicum annuum L. seedlings. The ability of chitinolytic bacteria to suppress the disease was evaluated by soaking red chili seeds in the bacterial isolates solution for 30 minutes prior seedling. Percentage of seedling of treated chili seed at end of study (4-weeks ranging from 46 to 82.14%. Relative reduction of the seedling damping-off was observed in all bacterial treatment ranged from 28.57 to 60.71%. Furthermore, manifestation of bacterial suppression to Fusarium wilt was also exhibited by increasing of seedling height (ranged from 7.33 to 7.87 cm compared to 6.88 cm and dry-weight (ranged from 2.7 to 4.3 mg compared to 2.3 mg. However, no significant effect was observed in leaf number. Then, from all chitinolytic isolates tested, BK08 was the most potential candidate for biological control agent of Fusarium wilt in chili seedling.

  14. Effects of stage of maturity at harvest, wilting and LAB inoculant on aerobic stability of wheat silages

    DEFF Research Database (Denmark)

    Weinberg, Z.G.; Khanal, Prabhat; Chen, Y.;

    2010-01-01

    The objective was to study effects of cultivar, stage of maturity at harvest, wilting, and addition of lactic acid bacterial (LAB) inoculant at ensiling, and their interactions, on the aerobic stability of wheat silages. Wheat of two cultivars, harvested at the flowering or the milk stage...... to the results with cultivar, stage of maturity, wilting and inoculant as main effects, as well as their interactions. Cultivar and LAB inoculant had effects on silage composition and aerobic stability, with stage of maturity having an effect on aerobic losses, whereas wilting did not have effects on aerobic...

  15. Control of tomato bacterial wilt through the incorporation of aerial part of pigeon pea and crotalaria to soil Controle da murcha bacteriana do tomateiro pela incorporação da parte aérea de guandu e crotalária no solo

    Directory of Open Access Journals (Sweden)

    Suane C. Cardoso

    2006-03-01

    Full Text Available The use of organic matter that improves the physical, chemical and biological soil properties has been studied as an inducer of suppressiveness to soilborne plant pathogens. The objective of this work was to evaluate the effect of different sources and concentrations of organic matter on tomato bacterial wilt control. Two commercially available organic composts and freshly cut aerial parts of pigeon pea (Cajanus cajan and crotalaria (Crotalaria juncea were incorporated, in concentrations of 10, 20 and 30 % (v/v, into soil infested with Ralstonia solanacearum. The soil with the fresh organic matter of pigeon pea and crotalaria was incubated for 30 and 60 days before planting. Tomato seedlings of cv. Santa Clara were transplanted into polyethylene bags with 3 kg of the planting substrate (infested soil + organic matter. The wilting symptoms and percentage of flowering plants were evaluated for 45 days. All evaluated concentrations with incorporation and incubation for 30 days of aerial parts of pigeon pea and crotalaria controlled 100% tomato bacterial wilt. With 60 days of incubation, only the 10 % concentration of pigeon pea and crotalaria did not control the disease. These results suggest that soil incorporation of fresh aerial parts of pigeon pea and crotalaria is an effective method for bacterial wilt control.A utilização de materiais orgânicos que melhoram as características físicas, químicas e biológicas do solo vem sendo estudada como indutora de supressividade a fitopatógenos habitantes do solo. Este trabalho teve como objetivo avaliar o efeito de diferentes fontes e concentrações de matéria orgânica no controle da murcha bacteriana do tomateiro. Foram avaliados dois compostos orgânicos comerciais e a matéria fresca cortada da parte aérea de guandu (Cajanus cajan e de crotalária (Crotalaria juncea, nas concentrações 10, 20 e 30 % (v/v, incorporados no solo infestado com Ralstonia solanacearum. O solo que recebeu a parte

  16. Efeito da solarização e biofumigação, durante o outono, na incidência de murcha-bacteriana e produtividade da batata Effect of soil solarization and biofumigation during autumn on bacterial wilt incidence and potato yield

    Directory of Open Access Journals (Sweden)

    Mírian Josefina Baptista

    2006-03-01

    Full Text Available A murcha-bacteriana causada por Ralstonia solanacearum é uma das principais doenças da cultura da batata. A solarização tem sido estudada como opção para a desinfestação do solo e tem potencial para o controle da murcha bacteriana. A técnica é indicada para uso nas estações quentes do ano pois depende de condições climáticas adequadas. Devido ao período de plantio de determinadas culturas, é interessante avaliar o uso da solarização em outras épocas do ano e associada a outras técnicas para garantir sua eficiência. A biofumigação é a desinfestação do solo através da adição de matéria orgânica que, durante sua decomposição, libera substâncias tóxicas aos fitopatógenos. Neste trabalho avaliou-se durante o outono (maio a junho os efeitos da adição de cama de aves (biofumigação e da solarização na incidência natural da murcha-bacteriana e na produtividade da batata, através dos tratamentos: adição de cama de aves (20 t/ha, uréia (100 kg/ha, aplicação de brometo de metila e solo sem tratamento (testemunha, todos solarizados ou não solarizados. Avaliou-se a produção de tubérculos totais e comerciais e, a partir da incidência de murcha-bacteriana, foi feito o cálculo da área abaixo da curva de progresso da doença (AACPD. Na área infestada, apenas o uso do brometo de metila proporcionou reduções significativas na incidência da murcha-bacteriana. No entanto, a aplicação de brometo de metila e a adição de cama de aves em associação com a solarização possibilitaram produção significativamente maior de tubérculos de batata em relação à testemunha. Os efeitos da solarização associada à biofumigação com cama de aves sobre a produtividade da batata em área infestada com R. solanacearum devem ser melhor investigados.Bacterial wilt caused by Ralstonia solanacearum is one of the most important diseases of the potato. Soil solarization has been studied as an option for soilborne

  17. Progress Toward Breeding for Verticillium Wilt Resistance

    Science.gov (United States)

    Verticillium wilt is a persistent and serious problem in potato production. Host plant resistance offers an attractive long-term control method. Breeding progress depends on access to germplasm carrying resistance genes. This study was carried out to identify sources of Verticillium wilt resistan...

  18. 番茄青枯病罹病植株和健康植株根际土壤理化性状及生物学特性的比较%Physical,Chemical and Biological Characteristics Analysis of Rhizosphere Soils between Infected Plants of Tomato Bacterial Wilt and Non-infected Plants

    Institute of Scientific and Technical Information of China (English)

    杨尚东; 吴俊; 赵久成; 郭伊娟; 龙明华

    2013-01-01

    A comparative study was conducted to analyze the physical,chemical and biological characteristics of rhizosphere soils between infected plants of tomato(Lycopersicon esculentum Mill.) bacterial wilt and non-infected plants.The results showed that the soil pH and organic matter(OM), total nitrogen,phosphorus and potassium contents,and alkaline nitrogen,rapid available phosphorus and potassium contents,etc.abiotic factors in rhizosphere soils of infected plants showed a downward trend,especially the dropping tendency in contents of alkaline nitrogen,rapid available phosphorus and potassium were significantly.In addition,the numbers of culturable bacteria and actinnomycetes were significantly decreased in rhizosphere soil of bacterial wilt infected plants,while the numbers of culturable fungi were very significantly increased.Meanwhile,the activities ofβ-Glucosidase,Phos-phatase and Protease,biomass C and N were all significantly decreased.%采用对比分析的方法,研究了广西主要番茄产区青枯病罹病植株和健康植株根际土壤的理化性状和生物学特性。结果表明:与健康植株相比,番茄青枯病罹病植株根际土壤pH值、有机质、全氮、全磷、全钾含量以及碱解氮、速效磷、速效钾含量等非生物因子均呈下降趋势,尤其是碱解氮、速效磷和速效钾含量的下降趋势尤为显著。另一方面,番茄青枯病罹病植株根际土壤中可培养细菌、放线菌数量极显著减少,而可培养真菌数量极显著增加;同时,涉及碳、氮、磷循环的相关酶(β-葡糖苷酶、磷酸酶、蛋白酶)活性和微生物生物量碳、氮显著或极显著降低。

  19. Murcha-de-curtobacterium do feijoeiro no Estado de Santa Catarina e reação de genótipos a Curtobacterium flaccumfaciens pv. flaccumfaciens Bacterial wilt of common bean in Santa Catarina State, Brazil, and behavior of genotypes to Curtobacterium flaccumfaciens pv. flaccumfaciens

    Directory of Open Access Journals (Sweden)

    Gustavo de Faria Theodoro

    2006-03-01

    Full Text Available Avaliou-se a ocorrência da murcha-de-curtobacterium em lavouras de feijoeiro comum em algumas localidades do Estado de Santa Catarina, nas safras 2002/03 e 2003/04, e o comportamento dos genótipos BRS Valente, Carioca, CHC 97-29, CHP 97-26, CNPF 8104, Diamante Negro, Empasc 201 - Chapecó, IAPAR 44, IPR Graúna, IPR Juriti, IPR Uirapuru, LP 9728, Pérola, SCS 202-Guará, Sel. CP 9310635, TPS Bionobre, TPS Bonito, TPS Magnífico, TPS Nobre, TPS Soberano e Xamego perante Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff, em condições de casa-de-vegetação. As cultivares IAC Carioca Akytã, IAC Carioca Aruã e IAC Carioca Pyatã foram empregadas como padrões de resistência a Cff. As avaliações dos sintomas ocorreram aos 5, 10, 15, 20 e 25 dias após a inoculação (DAI e, posteriormente, foi estimada a área abaixo da curva de progresso da murcha-de-curtobacterium (AACPMC, em cada genótipo. A doença esteve presente nos municípios de Campos Novos, Faxinal dos Guedes, Guatambu, Ipuaçu, Ponte Serrada e Tigrinhos e que, aos 10 DAI, as cultivares SCS 202 - Guará e IPR Juriti mostraram baixa severidade. Porém, aos 25 DAI, somente as cultivares padrões foram resistentes e apresentaram menor AACPMC.It was evaluated the occurrence of bacterial wilt in localities of Santa Catarina State, during the harvest of 2002/03 and 2003/04, and the behavior of the genotypes BRS Valente, Carioca, CHC 97-29, CHP 97-26, CNPF 8104, Diamante Negro, Empasc 201 - Chapecó, IAPAR 44, IPR Graúna, IPR Juriti, IPR Uirapuru, LP 9728, Pérola, SCS 202 - Guará, Sel. CP 9310635, TPS Bionobre, TPS Bonito, TPS Magnífico, TPS Nobre, TPS Soberano and Xamego to Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff, under greenhouse conditions. The cultivars IAC Carioca Akytã, IAC Carioca Aruã, and IAC Carioca Pyatã were used as patterns of resistance to Cff. The evaluations of the symptoms were performed at 5, 10, 15, 20, and 25 days after inoculation (DAI and

  20. Continous application of bioorganic fertilizer induced resilient culturable bacteria community associated with banana Fusarium wilt suppression

    Science.gov (United States)

    Fu, Lin; Ruan, Yunze; Tao, Chengyuan; Li, Rong; Shen, Qirong

    2016-01-01

    Fusarium wilt of banana always drives farmers to find new land for banana cultivation due to the comeback of the disease after a few cropping years. A novel idea for solving this problem is the continuous application of bioorganic fertilizer (BIO), which should be practiced from the beginning of banana planting. In this study, BIO was applied in newly reclaimed fields to pre-control banana Fusarium wilt and the culturable rhizobacteria community were evaluated using Biolog Ecoplates and culture-dependent denaturing gradient gel electrophoresis (CD-DGGE). The results showed that BIO application significantly reduced disease incidences and increased crop yields, respectivly. And the stabilized general bacterial metabolic potential, especially for the utilization of carbohydrates, carboxylic acids and phenolic compounds, was induced by BIO application. DGGE profiles demonstrated that resilient community structure of culturable rhizobacteria with higher richness and diversity were observed in BIO treated soils. Morever, enriched culturable bacteria affiliated with Firmicutes, Gammaproteobacteria and Actinobacteria were also detected. In total, continuous application of BIO effectively suppressed Fusarium wilt disease by stabilizing culturable bacterial metabolic potential and community structure. This study revealed a new method to control Fusarium wilt of banana for long term banana cultivation. PMID:27306096

  1. Continous application of bioorganic fertilizer induced resilient culturable bacteria community associated with banana Fusarium wilt suppression.

    Science.gov (United States)

    Fu, Lin; Ruan, Yunze; Tao, Chengyuan; Li, Rong; Shen, Qirong

    2016-01-01

    Fusarium wilt of banana always drives farmers to find new land for banana cultivation due to the comeback of the disease after a few cropping years. A novel idea for solving this problem is the continuous application of bioorganic fertilizer (BIO), which should be practiced from the beginning of banana planting. In this study, BIO was applied in newly reclaimed fields to pre-control banana Fusarium wilt and the culturable rhizobacteria community were evaluated using Biolog Ecoplates and culture-dependent denaturing gradient gel electrophoresis (CD-DGGE). The results showed that BIO application significantly reduced disease incidences and increased crop yields, respectivly. And the stabilized general bacterial metabolic potential, especially for the utilization of carbohydrates, carboxylic acids and phenolic compounds, was induced by BIO application. DGGE profiles demonstrated that resilient community structure of culturable rhizobacteria with higher richness and diversity were observed in BIO treated soils. Morever, enriched culturable bacteria affiliated with Firmicutes, Gammaproteobacteria and Actinobacteria were also detected. In total, continuous application of BIO effectively suppressed Fusarium wilt disease by stabilizing culturable bacterial metabolic potential and community structure. This study revealed a new method to control Fusarium wilt of banana for long term banana cultivation. PMID:27306096

  2. Recovery Plan for Laurel Wilt of Avocado

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial avocado production in Florida, as well as the National Germplasm Repository for avocado in Miami (USDA-ARS). Elsewhere in the US, major (California) and minor comm...

  3. Effect of Chitinase-Producing Strain V-8 on 3ontrolling Cotton Fusarium Wilt

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] This study aimed to screen endophytic bacteria which is antag- onistic to cotton Fusarium wilt. [Method] Fresh cotton plants collected from cotton- growing areas in Jingzhou City, Hubei Province were used as experimental materials to isolate endophytic bacteria. Through chitinase test and co-culturing both micro-or- ganisms side by side on the same PDA culture plate, antagonistic strains to cotton Fusarium wilt were screened. [Result] A total of 83 bacterial isolates were obtained from cotton plants grown in the fields, six of which were chitinase-productive bacte- ria. Through chitinase test and co-culturing both micro-organisms side by side on the same PDA culture plate, strain V-8 which had the strongest antagonistic effect on Fusarium oxysporum f. sp. vasinfectum was screened. Strain V-8 had a wider anti- fungal spectrum with certain inhibitory effect on all the six important pathogenic fungi including Fusarium oxysporum f. sp niveum; it colonized stably in the rhizospheric soil of cotton, with a colonization density of up to 6.2x10s cfu/g fifty days after inoc- ulation; the relative effect on controlling cotton Fusarium wilt in pot test was 73.2%. The Findings of this study suggested that strain V-8 had great potential for biological control of cotton Fusarium wilt and could be taken as a substantial material for the cloning of chitinase genes. [Conclusion] The results from this study provides bases for the control of cotton fusarium wilt, as well as the exploitation of endophytic bac- teria resources in cotton and the development of novel biological pesticides.

  4. Illumina-based analysis of the rhizosphere microbial communities associated with healthy and wilted Lanzhou lily (Lilium davidii var. unicolor) plants grown in the field.

    Science.gov (United States)

    Shang, Qianhan; Yang, Guo; Wang, Yun; Wu, Xiukun; Zhao, Xia; Hao, Haiting; Li, Yuyao; Xie, Zhongkui; Zhang, Yubao; Wang, Ruoyu

    2016-06-01

    Lanzhou lily (Liliumdavidii var. unicolor) is the best edible lily as well as a traditional medicinal plant in China. The microbes associated with plant roots play crucial roles in plant growth and health. However, little is known about the differences of rhizosphere microbes between healthy and wilted Lanzhou lily (Lilium davidii var. unicolor) plants. The objective of this study was to compare the rhizosphere microbial community and functional diversity of healthy and wilted plants, and to identify potential biocontrol agents with significant effect. Paired end Illumina Mi-Seq sequencing of 16S rRNA and ITS gene amplicons was employed to study the bacterial and fungal communities in the rhizosphere soil of Lanzhou lily plants. BIOLOG technology was adopted to investigate the microbial functional diversity. Our results indicated that there were major differences in the rhizosphere microbial composition and functional diversity of wilted samples compared with healthy samples. Healthy Lanzhou lily plants exhibited lower rhizosphere-associated bacterial diversity than diseased plants, whereas fungi exhibited the opposite trend. The dominant phyla in both the healthy and wilted samples were Proteobacteria and Ascomycota, i.e., 34.45 and 64.01 %, respectively. The microbial functional diversity was suppressed in wilted soil samples. Besides Fusarium, the higher relative abundances of Rhizoctonia, Verticillium, Penicillium, and Ilyonectria (Neonectria) in the wilted samples suggest they may pathogenetic root rot fungi. The high relative abundances of Bacillus in Firmicutes in healthy samples may have significant roles as biological control agents against soilborne pathogens. This is the first study to find evidence of major differences between the microbial communities in the rhizospheric soil of healthy and wilted Lanzhou lily, which may be linked to the health status of plants. PMID:27116961

  5. Identification and biocontrol efficacy of Streptomyces miharaensis producing filipin III against Fusarium wilt.

    Science.gov (United States)

    Kim, Jeong Do; Han, Jae Woo; Hwang, In Cheon; Lee, Dongho; Kim, Beom Seok

    2012-04-01

    A number of bacterial strains were isolated from the internal tissue of Trapa japonica. Of these, strain KPE62302H, which had a 16S rDNA sequence identical to that of Streptomyces miharaensis showed antifungal activity against several plant pathogens. Treatment of seeds with strain KPE62302H induced a significant reduction in the incidence of Fusarium wilt in tomato plants compared with untreated controls. An antifungal substance (FP-1) was purified from the culture extract of strain KPE62302H using C18 flash and Sephadex LH-20 column chromatography and reverse phase HPLC. Extensive spectrometric analysis using MS and NMR identified this as filipin III. FP-1 inhibited the mycelial growth of plant pathogenic fungi such as Alternaria mali, Aspergillus niger, Colletotrichum gloeosporioides, C. orbiculare, Cylindrocarpon destructans, Diaporthe citiri, Fusarium oxysporum at 1-10 μg ml(-1) and also markedly inhibited the development of Fusarium wilt caused by F. oxysporum f.sp. lycopersici in tomato plants by treatment with 10 μg ml(-1) under greenhouse conditions. The efficacy of FP-1 against Fusarium wilt was comparable to that of the synthetic fungicide benomyl. An egfp -tagged strain of KPE62302H confirmed its ability to colonize tomato plants. PMID:22460913

  6. Immunofluorescence localization and ultrastructure of Stewart’s wilt disease bacterium Pantoea stewartii in maize leaves and in its flea beetle vector Chaetocnema pulicaria (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    Pantoea stewartii is the causal agent of Stewart's wilt of sweet corn, the most serious bacterial disease of sweet corn and maize in the North-Central and Eastern USA. P. stewartii is transmitted mainly by the corn flea beetle Chaetocnema pulicaria (Coleoptera: Chrysomelidae) and this bacterium is a...

  7. Alleviating Effect of Phenol Compounds on Cucumber Fusarium Wilt and Mechanism

    Institute of Scientific and Technical Information of China (English)

    YUAN Fei; ZHANG Chun-lan; SHEN Qi-rong

    2003-01-01

    The amount of phenol compounds in the soil increased after adding organic material into the soil. It was found that p-hydroxybenzoic acid, p-coumaric acid and frulic acid alleviated Fusarium wilt of cucumber, the alleviating effect of p-hydroxybenzoic acid was the best, followed by p-coumaric acid and frulic acid. The total amount of bacterial, actinomyces and fungus in high phenol compounds treatment decreased than that of control treatment, while the microorganisms' amount in low phenol compounds treatment increased. Phenol compounds inhibit the growth of pathogen.

  8. Characterization of an RTX-Like Toxin and an Alpha-2-Macroglobulin in Pantoea stewartii subsp. stewartii, Causal Agent of Stewart's Wilt of Sweet Corn

    OpenAIRE

    Williams, Kayla Marie

    2014-01-01

    Pantoea stewartii subsp. stewartii DC283, the causal agent of Stewart's wilt, is an important bacterial pathogen of sweet corn. P. stewartii colonizes the apoplastic space and xylem tissue, resulting in characteristic water-soaked (WS) lesions and wilting. A gene encoding a putative RTX-like toxin, rtx2, has been identified in P. stewartii. RTX toxins belong to the pore-forming toxin family and have lytic properties in animal systems. Little is known about the role of RTX toxins in plant path...

  9. Characterization of Verticillium dahliae isolates and wilt epidemics of pepper

    OpenAIRE

    Bhat, R G; Smith, R F; Koike, S.T.; Wu, B M; Subbarao, K.V.

    2003-01-01

    Epidemics of Verticillium wilt in pepper fields of the central coast of California and isolates of Verticillium dahliae associated with these epidemics were characterized. The mean incidence of wilted plants per field ranged from 6.3 to 97.8% in fields with Anaheim, jalapeno, paprika, or bell peppers. In general, incidence of wilt in jalapeno and bell pepper crops was lower than in crops of other types of pepper. Inoculum density of V. dahliae in the surveyed pepper fields ranged from 2.7 to ...

  10. Suppression of Verticillium Wilt of Olive by Pseudomonas fluorescens

    OpenAIRE

    Sanei, S. J.; Razavi, S. E.

    2011-01-01

    Protection of pathogen-free olive planting material from infection by Verticillium dahliae during plant propagation and/or at planting would help in the management of Verticillium wilt of olive. Despite the importance for rhizosphere functioning, rhizobacterial Pseudomonas spp. have been mainly studied in a cultivation-based manner. In this study, 8 isolates of Pseudomonas fluorescens obtained from roots of olive plants were tested for suppression of Verticillium wilt in nursery-produced oliv...

  11. Pattern of genetic diversity among Fusarium wilt resistant castor germplasm accessions (Ricinus communis L.

    Directory of Open Access Journals (Sweden)

    K. Anjani

    2010-03-01

    Full Text Available Wilt caused by Fusarium oxysporum f.sp. ricini (Wr Gordon is one of the major yield losing diseases in castor.Cultivating wilt resistant cultivars is an effective strategy to control the disease. Utilization of diverse sources ofstable resistance is a prerequisite for durable resistance breeding. The experiment was conducted to identifygenetically diverse resistant sources in castor germplasm. Genetic diversity among 20 identified wilt resistantgermplasm was assessed using multivariate classificatory methods. Wide genetic diversity was demonstratedamong these accessions. These accessions are valuable in wilt resistance breeding programme. They wouldserve as base diverse material for wilt resistance breeding, wilt resistant genepool construction and moleculartagging of resistant genes.

  12. Successful strategy for the selection of new strawberry-associated rhizobacteria antagonistic to Verticillium wilt.

    Science.gov (United States)

    Berg, G; Kurze, S; Buchner, A; Wellington, E M; Smalla, K

    2000-12-01

    In order to isolate and characterize new strawberry-associated bacteria antagonistic to the soil-borne pathogenic fungus Verticillium dahliae Kleb., rhizobacterial populations from two different strawberry species, Greenish Strawberry (Fragaria viridis) and Garden Strawberry (F. x ananassa) obtained after plating onto King's B and glycerol-arginine agar, were screened for in vitro antagonism toward V. dahliae. The proportion of isolates with antifungal activity determined in in vitro assay against V. dahliae was higher for the Garden Strawberry than for the Greenish Strawberry. From 300 isolates, 20 isolates with strong antifungal activity were selected characterized by physiological profiling and molecular fingerprinting methods. Diversity among the isolates was characterized with molecular fingerprints using amplified ribosomal DNA restriction analysis (ARDRA) and the more discriminating BOX-PCR fingerprint method. The physiological profiles were well correlated with molecular fingerprinting pattern analysis. Significant reduction of Verticillium wilt by bacterial dipping bath treatment was shown in the greenhouse and in fields naturally infested by V. dahliae. The relative increase of yield ranged from 117% (Streptomyces albidoflavus S1) to 344% (Pseudomonas fluorescens P10) in greenhouse trials, and 113% (Streptomyces albidoflavus S1) to 247% (Pseudomonas fluorescens P6) in field trials. Evaluation resulted in the selection of three effective biocontrol agents (Pseudomonas fluorescens P6, P10, and Streptomyces diastatochromogenes S9) antagonistic to the Verticillium wilt pathogen. PMID:11142403

  13. Detection of Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis in Maize by Loop-Mediated Amplification.

    Science.gov (United States)

    Yasuhara-Bell, Jarred; de Silva, Asoka; Heuchelin, Scott A; Chaky, Jennifer L; Alvarez, Anne M

    2016-03-01

    The Goss's wilt pathogen, Clavibacter michiganensis subsp. nebraskensis, can cause considerable losses in maize (Zea mays) production. Diagnosis of Goss's wilt currently is based on symptomology and identification of C. michiganensis subsp. nebraskensis, following isolation on a semiselective medium and/or serological testing. In an effort to provide a more efficient identification method, a loop-mediated amplification (LAMP) assay was developed to detect the tripartite ATP-independent periplasmic (TRAP)-type C4-dicarboxylate transport system large permease component and tested using strains of C. michiganensis subsp. nebraskensis, all other C. michiganensis subspecies and several genera of nontarget bacteria. Only strains of C. michiganensis subsp. nebraskensis reacted positively with the LAMP assay. The LAMP assay was then used to identify bacterial isolates from diseased maize. 16S rDNA and dnaA sequence analyses were used to confirm the identity of the maize isolates and validate assay specificity. The Cmm ImmunoStrip assay was included as a presumptive identification test of C. michiganensis subsp. nebraskensis at the species level. The Cmn-LAMP assay was further tested using symptomatic leaf tissue. The Cmn-LAMP assay was run in a hand-held real-time monitoring device (SMART-DART) and performed equally to in-lab quantitative polymerase chain reaction equipment. The Cmn-LAMP assay accurately identified C. michiganensis subsp. nebraskensis and has potential as a field test. The targeted sequence also has potential application in other molecular detection platforms. PMID:26595113

  14. The effects of wilting and storage temperatures on the fermentation quality and aerobic stability of stylo silage.

    Science.gov (United States)

    Liu, Qinghua; Zhang, Jianguo; Shi, Shangli; Sun, Qizhong

    2011-08-01

    In order to clarify the ensiling characteristics of stylo (Stylosanthes guianensis Swartz), the effects of wilting (no wilting, light wilting and heavy wilting) and storage temperatures (10°C, 20°C, 30°C and 40°C) on the fermentation quality and aerobic stability of stylo silage were investigated. Wilting had no significant influence on the contents of crude protein, ether extract and acid detergent fiber, and numbers of lactic acid bacteria, aerobic bacteria, yeasts and mold (P > 0.05). Heavy wilted material, wilted for 12 h, had higher neutral detergent fiber content and lower water-soluble carbohydrate content than unwilted and light wilted materials (P silage (P silage. In all the silages, no wilting silage ensiled at 30°C had the highest butyric acid content (P silage, irrespective of wilting. The wilted silage or silage stored at low temperature had poor aerobic stability. PMID:21794013

  15. Changes of RWC, Wilting Degree and ABA in Different Ramie Varieties under Drought Stress

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Changes of RWC, wilting degree and ABA in different ramie varieties under drought stress were studied. The results showed: (1) wilting degree and ABA increased but RWC decreased with the increase of drought sress,and (2) drought resistant varieties had higher RWC and ABA but lower wilting degree than drought sensitive varieties.

  16. Control of Fusarium wilt in banana with Chinese leek

    OpenAIRE

    Huang, Y H; Wang, R C; Li, C. H.; Zuo, C.W.; Wei, Y. R.; Zhang, L.; Yi, G.J.

    2012-01-01

    The inhibitory effects of Chinese leek(Allium tuberosum) on Fusarium oxysporum f. sp. cubense (Foc) and on Fusarium wilt incidence were studied in order to identify a potential efficient way to control the disease. Adopting the rotation system of Chinese leek-banana reduced the Fusarium wilt incidence and disease severity index by 88 %-97 % and 91 %-96 %, respectively, improved the crop value by 36 %-86 %, in an area heavily infested by Foc between 2007 and 2009. As a result of inoculation in...

  17. Verticillium Wilt Resistance Evaluation of Wisconsin Breeding Clones

    Science.gov (United States)

    Verticillium wilt is one of the most widespread and persistent problems encountered by potato producers. In Wisconsin, it is caused in large part by the fungal pathogen Verticillium dahliae. Soil fumigation is currently the only consistently effective control measure. However, host plant resistan...

  18. Discovery of Fusarium wilt race 4 resistance in cotton

    Science.gov (United States)

    Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans)] is a soil-inhabiting fungus that can survive for long periods in the absence of a host, making it impractical to eradicate from infested fields. This cotton host specific forms of the fungus is comprised of different genotyp...

  19. Influence of soil type on the wilting of plants

    Science.gov (United States)

    Czyż, E. A.; Dexter, A. R.

    2013-12-01

    It has been shown that the water remaining in soil when plants wilt due to soil limitations and the residual water content as observed when soils are de-watered in pressure cell apparatus are essentially the same. Both are produced by immiscible displacement of water by air, and this leads to the water remaining in soil not being in thermodynamic equilibrium. Water removal by immiscible displacement ceases when hydraulic cut-off is reached. The point of hydraulic cut-off may be calculated by fitting waterretention data to equations for both the non-equilibrium case and the equilibrium case, and then solving these simultaneously. This has been done forwater retention data for 52 soil horizons in Poland. These results are used to obtain a pedotransfer function for the permanent wilting point due to soil limitations and the results are presented for the different soil texture classes. The pore water suction when wilting occurs is estimated to be 1.0 MPa. The methods and findings in this paper are used to explain a range of published results on plant wilting.

  20. Laurel wilt in avocado: Review of an emerging disease

    Science.gov (United States)

    aurel wilt, caused by the vascular fungus Raffaelea lauricola, is transmitted by the redbay ambrosia beetle, Xyleborus glabratus, and affects many plants in the family Lauraceae. It was introduced into the United States around 2002 through infested packing material arriving in Georgia. In Florida, t...

  1. Fungal diversity associated with verticillium wilt of cotton

    International Nuclear Information System (INIS)

    The association of fungal diversity with Verticillium wilt is rarely known, which is important to know for the control of this detrimental disease. Our study is the preliminary attempt to find the associations of fungal diversity with Verticillium wilt and provides the baseline information for biological control. About 30 different fungi from soil and 23 from cotton plants were isolated and confirmed through molecular characterization. The colony forming unit (CFU)/g dry soil of fungi before and after planting cotton showed significant variation among all the fungi. The overall frequency of all fungi for soil after sowing was significantly higher than before sowing. A. alternata, F. equiseti, F. concentricum, A. flavus, F. proliferatum, and Chaetomium sp. associated with high resistance (Arcot-1) to Verticillium wilt, whereas, V. dahliae, A.niger and Paecilomyces sp., with high susceptible (Arcot-438) germplasm. However, T. basicola, C. ramotenellum and G. intermedia were isolated from both. Soil plating was comparatively easiest than soil dilution method for the determination of frequency percentage, however, later method is useful for the screening of single spore isolation. Most of the antagonistic species were screened from soil; nevertheless, Paecilomyces and Chaetomium spp. were screened from plant and soil. In vitro test of T. longibrachiatum. T. atroviride, Paecilomyces and T. viride showed the strongest efficacy against V. dahliae. These efficient bio-agents can be used as an effective tool for other future studies regarding to Verticillium wilt of cotton. (author)

  2. Laurel wilt: A global threat to avocado production

    Science.gov (United States)

    Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial avocado production in Florida, as well as the National Germplasm Repository for avocado in Miami (USDA-ARS). Elsewhere in the US, major (California) and minor comm...

  3. Environmental influences on pigeonpea-Fusarium udum interactions and stability of genotypes to Fusarium wilt.

    Directory of Open Access Journals (Sweden)

    Mamta eSharma

    2016-03-01

    Full Text Available Fusarium wilt (Fusarium udum Butler is an important biotic constraint to pigeonpea (Cajanus cajan L. production worldwide. Breeding for fusarium wilt resistance continues to be an integral part of genetic improvement of pigeonpea. Therefore, the study was aimed to identify and validate resistant genotypes to fusarium wilt and determine the magnitude of genotype × environment (G × E interactions through multi-environment and multi-year screening. Total 976 genotypes including germplasm and breeding lines were screened against wilt in wilt sick plot at Patancheru, India. Ninety two genotypes found resistant to wilt were tested further for two more years in wilt sick plot at Patancheru and Pigeonpea Wilt Nursery (PWN comprising of 29 genotypes was constituted. PWN was evaluated at nine locations representing different agro-climatic zones of India for wilt resistance during two crop seasons 2007/08 and 2008/09. Genotypes (G, environment (E and G × E interactions biplot partitioned main effect into G, E and G × E interactions and significant effects (p≤0.001 were obtained for wilt incidence. Genotype contributed 36.51% of resistance variation followed by environment (29.32%. GGE biplot in integration with boxplot and multiple comparison tests enabled us to identify seven stable genotypes (ICPL 20109, ICPL 20096, ICPL 20115, ICPL 20116, ICPL 20102, ICPL 20106 and ICPL 20094 based on their performance across diverse environments. These genotypes have broad based resistance and can be exploited in pigeonpea breeding program.

  4. Identification of resistant sources in chickpea against fusarium wilt

    International Nuclear Information System (INIS)

    Wilt caused by Fusarium oxysporum Schlechtend.Fr. f. sp. ciceris is a devastating disease of chickpea in Pakistan. In the present study 321 genotypes from different sources were evaluated under controlled condition to identify genetic sources of resistance against this disease at seedling and reproductive stage. Disease reaction at two stages revealed considerable variation among the genotypes. At seedling stage disease incidence varied from 0 to 29.3% whereas at reproductive stage ranged from 0 to 57%. At seedling stage 173 genotypes were resistant, 54 were tolerant and 94 were susceptible, whereas at reproductive stage, 102 genotypes were resistant, 36 were tolerant and 183 were susceptible. Eighty two genotypes showed steady resistance at both stages. These genotypes may be exploited for the development of resistant cultivars against wilt. (author

  5. Use of radioisotopes in studying factors responsible for alfalfa resistance to bacterial wiltxng

    International Nuclear Information System (INIS)

    Studies are summarized dealing with possible causes of vascular dysfunction and resistance of alfalfa to bacterial wilting caused by Corynebacterium insidiosum (McCull.) H.L. Jens from the physiological and biochemical points of view. Using 32P, 35S, 54Mn, 45Ca, 65Zn, and 86Rb the uptake, distribution, translocation, and metabolism of these elements in plants with a different resistance against diseases were investigated. The possible use is discussed of 86Rb as a tracer of potassium. The results suggest that the resistance of alfalfa to bacterial wilting is probably determined by several factors. (author)

  6. Control of Fusarium Wilt of Chili With Chitinolytic Bacteria

    OpenAIRE

    DWI SURYANTO; SITI PATONAH; ERMAN MUNIR

    2010-01-01

    Biological control of plant disease using antagonistic microorganism has been obtaining much attention and implemented for decades. One of the potential microorganisms used in this strategy is chitinolytic bacteria. Utilization of this bacteria ranges from cell life, enzymes, genes, or other metabolites. In this study, we examined the ability of chitinolytic bacteria as a biocontrol agent of Fusarium wilt of red chili (Capsicum annuum L.) seedlings. The ability of chitinolytic bacteria to sup...

  7. Fusarium Wilt Suppression and Agglutinability of Pseudomonas putida†

    OpenAIRE

    Tari, P. H.; Anderson, A J

    1988-01-01

    Mutants of Pseudomonas putida (Agg−) that lack the ability to agglutinate with components present in washes of bean and cucumber roots showed limited potential to protect cucumber plants against Fusarium oxysporum f. sp. cucumerinum. However, a higher level of protection was observed against Fusarium wilt in cucumber plants coinoculated with the parental bacterium (Agg+), which was agglutinable. The Agg− mutants did not colonize the roots of cucumber plants as extensively as the Agg+ parental...

  8. The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties.

    Science.gov (United States)

    Zhao, Shuang; Chen, Xi; Deng, Shiping; Dong, Xuena; Song, Aiping; Yao, Jianjun; Fang, Weimin; Chen, Fadi

    2016-01-01

    Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC), the soil fumigant dazomet (DAZ), the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist) enhanced bio-organic fertilizer (BOF), and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F) ratios, Shannon-Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum. PMID:27110753

  9. Molecular research and genetic engineering of resistance to Verticillium wilt in cotton: A review

    Science.gov (United States)

    Verticillium dahliae, a soil-borne pathogen, causes Verticillium wilt, one of the most serious diseases in cotton, deleteriously influencing the crop’s production and quality. Verticillium wilt has become a major obstacle in cotton production since Helicoverpa armigera, the cotton bollworm, became e...

  10. Comparative genomics yields insights into niche adaptation of plant vascular wilt pathogens.

    Science.gov (United States)

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in osmola...

  11. Verticillium comparative genomics yields insights into niche adaptation by plant vascular wilt pathogens.

    Science.gov (United States)

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual losses. The characteristic vascular wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels. To gain insights into the mechan...

  12. Introduction of Bottle Gourd DNA into Watermelon by Soaking Embryo for Resistance to Wilt Disease

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to utilize wilt disease resistance of bottle gourd, total DNA of bottle gourd was introduced into watermelon through the method of soaking embryo. The DNA-introduced variant offsprings were cultured in contaminated soil to elect the wilt disease resistance for more than 3 generations. 2 high- resistant and 2 middle-resistant watermelon materials were obtained.

  13. Verticillium wilt in nursery trees: damage thresholds, spatial and temporal aspects

    NARCIS (Netherlands)

    Goud, J.C.; Termorshuizen, A.J.; Bruggen, van A.H.C.

    2011-01-01

    Verticillium wilt can cause high losses in tree nurseries. To be able to predict disease and unravel disease dynamics over time and space, the relationship between verticillium wilt and soil inoculum densities of Verticillium dahliae and the nematode Pratylenchus fallax was studied in two 4-year fie

  14. VIGOR OF PLANTLET FROM MICROPLANTLET TREATED BY FILTRATE AND CELL SUSPENSION OF SOME ISOLATES OF BACILLUS AND RESISTANCE TO BANANA WILT PATHOGEN AFTER ACCLIMATIZATION

    Directory of Open Access Journals (Sweden)

    Hadi wiyono

    2013-08-01

    Full Text Available Blood Disease Bacterium (BDB and Fusarium oxysporum f.sp. cubense (FOC is a couple wilt pathogen  of  banana.  These pathogens are the most important constraint in cultivation of banana in Indonesia.  In the integrated control strategy of the disease, the use of healthy seedlings produced from tissue culture technique is recommended.  The seedling produced by tissue culture technique however leads to lower vigor and susceptibility to the disease due to the aseptic work in vitro causing the beneficial bacterial endophytic to be eliminated. Therefore, the utility of the beneficial endophytic bacteria should be studied for recovering the vigor and resistance of the seedling.     Three isolates of endophytic Bacillus (B04, B05, B10 have been effective as growth promoter of microplantlet and antagonist of BDB and FOC in vitro.   Here then, this article reports the study results of the vigor of the plantlet (treated microplantlet by filtrate or cell suspension of the Bacillus after 3 months in acclimatization. The results were similar to the previous results on microplantlet in vitro, that Bacillus isolates B04, B05, and B10 were capable of promoting the growth and inducing the resistance to wilt pathogens on banana plantlets.  The treatments with bacterial cell inoculums were more effective than those bacterial filtrate. Isolate B10 was most potential followed by B05 and B04 respectively.

  15. Comparisons of the Effects of Elevated Vapor Pressure Deficit on Gene Expression in Leaves among Two Fast-Wilting and a Slow-Wilting Soybean

    Science.gov (United States)

    Devi, Mura Jyostna; Sinclair, Thomas R; Taliercio, Earl

    2015-01-01

    Limiting the transpiration rate (TR) of a plant under high vapor pressure deficit (VPD) has the potential to improve crop yield under drought conditions. The effects of elevated VPD on the expression of genes in the leaves of three soybean accessions, Plant Introduction (PI) 416937, PI 471938 and Hutcheson (PI 518664) were investigated because these accessions have contrasting responses to VPD changes. Hutcheson, a fast-wilting soybean, and PI 471938, a slow-wilting soybean, respond to increased VPD with a linear increase in TR. TR of the slow-wilting PI 416937 is limited when VPD increases to greater than about 2 kPa. The objective of this study was to identify the response of the transcriptome of these accessions to elevated VPD under well-watered conditions and identify responses that are unique to the slow-wilting accessions. Gene expression analysis in leaves of genotypes PI 471938 and Hutcheson showed that 22 and 1 genes, respectively, were differentially expressed under high VPD. In contrast, there were 944 genes differentially expressed in PI 416937 with the same increase in VPD. The increased alteration of the transcriptome of PI 416937 in response to elevated VPD clearly distinguished it from the other slow-wilting PI 471938 and the fast-wilting Hutcheson. The inventory and analysis of differentially expressed genes in PI 416937 in response to VPD is a foundation for further investigation to extend the current understanding of plant hydraulic conductivity in drought environments. PMID:26427064

  16. A bacterial pathogen uses distinct type III secretion systems to alternate between host kingdoms

    Science.gov (United States)

    Plant and animal-pathogenic bacteria utilize phylogenetically distinct type III secretion systems (T3SS) that produce needle-like injectisomes or pili for the delivery of effector proteins into host cells. Pantoea stewartii subsp. stewartii (Pnss), the causative agent of Stewart’s bacterial wilt and...

  17. Bacterial gastroenteritis

    Science.gov (United States)

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... Bacterial gastroenteritis can affect 1 person or a group of people who all ate the same food. It is ...

  18. [Relationships between summer drought and strong typhoon events and pine wilt disease occurrence in East Asia].

    Science.gov (United States)

    Wang, Fei

    2012-06-01

    The occurrence and prevalence of pine wilt disease cause huge losses to Japan, China, and South Korea in East Asia, and have received concerns from many countries. By the methods of field observation and meteorological data analysis, this paper studied the characteristics of the occurrence and prevalence of pine wilt disease and their relations to the meteorological disaster events. In Japan, China and South Korea, the meteorological extreme events of persistent summer drought and strong typhoon could trigger the occurrence of pine wilt. In extremely dry and hot environment, pine trees often appeared energy metabolism imbalance and entire tree wilt. However, in the years with lower temperature and more rainfall, less or nearly no pine wilt event occurred. It was suggested that before the attack by pine wood nematode and its vectors, the vigor of the pines had already declined, and thus, pine wilt disease could be confined in the areas often hit by summer drought and strong typhoon events. In the areas with suitable natural environment characterized by less summer drought and strong typhoon events and no improperly enlarged pine planting, there would be little possibility of widespread occurrence of pine wilt disease. PMID:22937641

  19. Studies on Cotton Breeding Resistant to Fusarium and Verticillium wilt Diseases

    Institute of Scientific and Technical Information of China (English)

    YE Peng-sheng; ZENG Hua-lan; WEI Shu-gu; ZHANG Yu; LI Qiong-ying

    2008-01-01

    @@ Both Fusarium and Verticillium wilts are important soil-borne diseases,which can not be effectively controlled by chemical fungicides.The two diseases,especially Verticillium wilt,have spread all over the cotton belt,and obstructed the progress of cotton production in China in recent years.It has been proven that breeding and growing resistant cultivars is one of the most economical and effective measures to control these diseases.The program of breeding cotton for resistance to wilt diseases has been continuously studied in Industrial Crops Research Institute,Sighuan Academy of Agricultural Sciences(ICRI-SAAS) for more than 50 years.

  20. Ralstonia solanacearum, a widespread bacterial plant pathogen in the post-genomic era

    OpenAIRE

    Peeters, Nemo; Guidot, Alice; Vailleau, Fabienne; Valls i Matheu, Marc

    2013-01-01

    Ralstonia solanacearum is a soil-borne bacterium causing the widespread disease known as bacterial wilt. Ralstonia solanacearum is also the causal agent of Moko disease of banana and brown rot of potato. Since the last R. solanacearum pathogen profile was published 10 years ago, studies concerning this plant pathogen have taken a genomic and post-genomic direction. This was pioneered by the first sequenced and annotated genome for a major plant bacterial pathogen and followed by many more gen...

  1. In vitro selection for resistance to Fusarium wilt in Banana

    International Nuclear Information System (INIS)

    Fusarium wilt or Panama disease, caused by the fungus Fusarium oxysporum f. sp. cubense (FOC), is one of the most serious diseases of banana in tropical and subtropical countries. Although there are banana cultivars resistant to the disease, transfer of the resistance trait to susceptible cultivars by traditional cross-breeding is difficult. In vitro selections of banana mutants tolerant to race 1 of FOC were carried out with fusaric acid and culture filtrate on multiple bud clumps. Regenerated plants showed tolerance to the disease in the greenhouse, and some of the plants also showed resistance in the field. Although the level of tolerance observed was not sufficiently high, in vitro selection by toxic substances extracted from pathogenic fungi resulted in an improvement of plant tolerance to the pathogen. Other selection factors for in vitro selection were reviewed, and a protocol for obtaining disease tolerant plants of banana is suggested. (author)

  2. Effect of Ditylenchus dipsaci and Pratylenchus penetrans on Verticillium Wilt of Alfalfa.

    Science.gov (United States)

    Vrain, T C

    1987-07-01

    Verticillium albo-atrum wilt symptoms appeared faster and were significantly more severe in the presence of Ditylenchus dipsaci in Vernal, a wilt-susceptible cultivar, than in Marls Kabul, a wilt-resistant cultivar. Winter kill in the field was not affected by the nematode during the first winter, but 50% of plants were killed in the second winter. Forage yield from nematode-infected plants was significantly reduced the second year. Interaction with V. albo-atrum did not significantly reduce forage yields below that of D. dipsaci alone. Pratylenchus penetrans did not increase the severity of wilt symptoms in the presence of V. albo-atrum, nor did it affect forage yield in the greenhouse. It did, however, reduce alfalfa yields in presence of V. albo-atrum under field conditions. D. dipsaci and P. penetrans reproduced faster in Vernal than in Maris Kabul when the fungus was present. PMID:19290158

  3. Integrated Management of Wilt Complex Disease in Bell Pepper (Capsicum annuum L.)

    OpenAIRE

    Tariq R. Rather; V. K. Razdan; Tewari, A. K.; Efath Shanaz; Z.A. Bhat; Mir G. Hassan; T. A. Wani

    2012-01-01

    Effect of various disease management tools on seedling emergence, wilt incidence and yield of bell pepper (Capsicum annuum L.) Var. California Wonder was studied as part of integrated management strategies under both glass house and field conditions. Different fungicides were tested against the four wilt pathogens viz, Fusarium oxysporum, Phytopthora capsici, Rhizoctonia solani and Sclerotium rolfsii under in- vitro conditions. The fungicides viz, Captan, Carbendazim, Metalaxyl and Carboxin w...

  4. Plant growth hormones suppress the development of Harpophora maydis, the cause of late wilt in maize

    OpenAIRE

    Degani, Ofir; Drori, Ran; Goldblat, Yuval

    2014-01-01

    Late wilt, a severe vascular disease of maize caused by the fungus Harpophora maydis, is characterized by rapid wilting of maize plants before tasseling and until shortly before maturity. The pathogen is currently controlled by resistant maize cultivars, but the disease is constantly spreading to new areas. The plant’s late phenological stage at which the disease appears suggests that plant hormones may be involved in the pathogenesis. This work revealed that plant growth hormones, auxin (Ind...

  5. Fusarium oxysporum as causal agent of tomato wilt and fruit rot

    OpenAIRE

    Maja Ignjatov; Dragana Milošević; Zorica Nikolić; Jelica Gvozdanović-Varga; Dušica Jovičić; Gordana Zdjelar

    2012-01-01

    Tomatoes are parasitized by a number of pathogens, including Fusarium oxysporum f. sp. lycopersici, causal agent of fusarium wilt. Fresh vegetable fruits can be contaminated with various fungi that produce mycotoxins, which is an important issue for human health. The objective of this paper was to isolate, determine, and identify causal organisms of tomato wilt and fruit rot, based on the pathogens morphological and molecular characteristics. Samples of dis...

  6. The xylem as battleground for plant hosts and vascular wilt pathogens

    OpenAIRE

    Koste A Yadeta; J. Thomma, Bart P. H.

    2013-01-01

    Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi, and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate and obstruct the transportation of water and minerals. As a consequence, leaves wilt and die, which may lead to impairment of the whole plant and eventually to death of the plant. Cultural, chemical...

  7. Rhizobacteria induces resistance against Fusarium wilt of tomato by increasing the activity of defense enzymes

    OpenAIRE

    Hélvio Gledson Maciel Ferraz; Renata Sousa Resende; Patrícia Ricardino Silveira; Camila Cristina Lage Andrade; Elisângela Aparecida Milagres; José Rogério Oliveira; Fabrício Ávila Rodrigues

    2014-01-01

    Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici (Fol), is one of the most important diseases that affect tomato yield worldwide. This study investigated the potential of three antagonists, Streptomyces setonii (UFV 618), Bacillus cereus (UFV 592) and Serratia marcescens (UFV 252), and as positive control the hormone jasmonic acid (JA), to reduce Fusarium wilt symptoms and to potentiate the defense enzymes in the stem tissues of tomato plants infected by Fol. The seeds were micro...

  8. Combining fluorescent Pseudomonas spp. strains to enhance suppression of fusarium wilt of radish

    OpenAIRE

    de Boer, Marjan; Sluis, Ientse van der; Loon, L.C. van; Bakker, P. A. H. M.

    2001-01-01

    Fusarium wilt diseases, caused by the fungus Fusarium oxysporum, lead to significant yield losses of crops. One strategy to control fusarium wilt is the use of antagonistic, root-colonizing Pseudomonas spp. It has been demonstrated that different strains of these bacteria suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol strains, and thus of several suppressive mechanisms, may represent a viable control strategy. A prerequisite for biocontrol by...

  9. Continous application of bioorganic fertilizer induced resilient culturable bacteria community associated with banana Fusarium wilt suppression

    OpenAIRE

    Lin Fu; Yunze Ruan; Chengyuan Tao; Rong Li; Qirong Shen

    2016-01-01

    Fusarium wilt of banana always drives farmers to find new land for banana cultivation due to the comeback of the disease after a few cropping years. A novel idea for solving this problem is the continuous application of bioorganic fertilizer (BIO), which should be practiced from the beginning of banana planting. In this study, BIO was applied in newly reclaimed fields to pre-control banana Fusarium wilt and the culturable rhizobacteria community were evaluated using Biolog Ecoplates and cultu...

  10. Progresses in the Mechanism of Resistance to Fusarium Wilt in Cucumber(Cucumis sativus L.)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xingang; WU Fengzhi; WANG Xuezheng; YUAN Ye

    2008-01-01

    Fusarium wilt caused by Fusarium oxysporum f.sp.cucumerinum (Owen) is one of the most devastating diseases in cucumber production worldwide.Recent progresses in the mechanism of resistance to Fusarium wilt in cucumber were reviewed in this paper,including pathogenic mechanism of Fusarium oxysporum,the resistance mechanism of cucumber,the heredity of resistance,and the location of resistance genes.Following works should be the location and cloning of resistance genes with molecular biologic methods.

  11. Detection of Laurel Wilt Disease in Avocado Using Low Altitude Aerial Imaging

    OpenAIRE

    Ana I de Castro; Ehsani, Reza; Ploetz, Randy C.; Jonathan H Crane; Buchanon, Sherrie

    2015-01-01

    Laurel wilt is a lethal disease of plants in the Lauraceae plant family, including avocado (Persea americana). This devastating disease has spread rapidly along the southeastern seaboard of the United States and has begun to affect commercial avocado production in Florida. The main objective of this study was to evaluate the potential to discriminate laurel wilt-affected avocado trees using aerial images taken with a modified camera during helicopter surveys at low-altitude in the commercial ...

  12. Study of fusarium wilt (Fusarium oxysporum f. sp. ciceris resistance in recombinant inbred line population of chickpea

    Directory of Open Access Journals (Sweden)

    Sidramappa, S. A. Patil, Shobharani.M and P. M. Salimath

    2011-06-01

    Full Text Available Wilt caused by Fusarium oxysporum f. sp. ciceris is a devastating disease of chickpea in India. One hundred and 26 RecombinantInbred Lines (RILs derived from a cross ICCV-2 x JG 62 along with six checks were evaluated for wilt resistance underunprotected natural infestation to identify the genetic sources for resistance. The genotypes were classified as highly resistant,moderately resistant, intermediate, susceptible and highly susceptible based on per cent plants wilted. Some of genotypesshowed high resistance to fusarium wilt. The per cent plants wilted in different lines ranged from O to 100 per cent. A total of45, 31, 25, 11 and 20 genotypes fell into highly resistant, moderately resistant, intermediate, susceptible and highly susceptibleclasses respectively. Less proportion of highly resistant genotypes were observed and it may be due to the fact that the wiltresistance was governed by recessive alleles. The resistant genotypes may be exploited for the development of resistant cultivarsagainst wilt.

  13. Detection of laurel wilt disease in avocado using low altitude aerial imaging.

    Science.gov (United States)

    de Castro, Ana I; Ehsani, Reza; Ploetz, Randy C; Crane, Jonathan H; Buchanon, Sherrie

    2015-01-01

    Laurel wilt is a lethal disease of plants in the Lauraceae plant family, including avocado (Persea americana). This devastating disease has spread rapidly along the southeastern seaboard of the United States and has begun to affect commercial avocado production in Florida. The main objective of this study was to evaluate the potential to discriminate laurel wilt-affected avocado trees using aerial images taken with a modified camera during helicopter surveys at low-altitude in the commercial avocado production area. The ability to distinguish laurel wilt-affected trees from other factors that produce similar external symptoms was also studied. RmodGB digital values of healthy trees and laurel wilt-affected trees, as well as fruit stress and vines covering trees were used to calculate several vegetation indices (VIs), band ratios, and VI combinations. These indices were subjected to analysis of variance (ANOVA) and an M-statistic was performed in order to quantify the separability of those classes. Significant differences in spectral values among laurel wilt affected and healthy trees were observed in all vegetation indices calculated, although the best results were achieved with Excess Red (ExR), (Red-Green) and Combination 1 (COMB1) in all locations. B/G showed a very good potential for separate the other factors with symptoms similar to laurel wilt-affected trees, such as fruit stress and vines covering trees, from laurel wilt-affected trees. These consistent results prove the usefulness of using a modified camera (RmodGB) to discriminate laurel wilt-affected avocado trees from healthy trees, as well as from other factors that cause the same symptoms and suggest performing the classification in further research. According to our results, ExR and B/G should be utilized to develop an algorithm or decision rules to classify aerial images, since they showed the highest capacity to discriminate laurel wilt-affected trees. This methodology may allow the rapid detection

  14. Effect of clove oil on plant pathogenic bacteria and bacterial wilt of tomato and geranium

    Science.gov (United States)

    We determined the antibacterial activity of clove oil against seven different genera of plant pathogenic bacteria including Gram-negative Agrobacterium tumefaciens, Erwinia carotovora pv. carotovora, Pseudomonas syringae pv. syringae, Ralstonia solanacearum, and Xanthomonas campestris pv. pelargonii...

  15. Murcha bacteriana no estado do Amazonas, Brasil Bacterial wilt in Amazonas State, Brazil

    OpenAIRE

    ROSALEE A. COELHO NETTO; Bianca G. Pereira; Hiroshi Noda; Bernard Boher

    2004-01-01

    Durante 1998 e 2000, a incidência de murcha bacteriana causada por Ralstonia solanacearum foi registrada em 25 municípios do estado do Amazonas. A bactéria foi encontrada nas seguintes espécies vegetais: Capsicum annuum, C. chinense, C. frutescens, Cucumis sativus, Heliconia sp., Lycopersicon esculentum, Melanthera discoidea, Moringa oleifera, Musa sp., Solanum melongena, S. gilo, e S. nigrum. Em tomateiros (Lycopersicon esculentum), a murcha bacteriana estava presente em todos os plantios. E...

  16. First report of bacterial wilt caused by Ralstonia solanacearum on Mesona chinensis in China

    Science.gov (United States)

    Jellywort (Mesona chinensis Benth) is a herbaceous plant in the Lamiaceae Family. The plant is referred to as ‘Xiancao’ (Weed from Angels) in Chinese and is primarily used to make grass jelly, a popular refreshing drink. Currently, Xiancao cultivation is a fast growing industry with a high profit ma...

  17. EFFICACY OF DIFFERENT INORGANIC MOLECULES ON WILT PATHOGEN OF CHICKPEA

    Directory of Open Access Journals (Sweden)

    S.Ranjitha Rani

    2014-11-01

    Full Text Available Chickpea (Cicer arietinum L. is one of the most important legumes grown in Asia. Though the area under this crop is more, the average yield per hectare is low because of several biotic and abiotic factors. Among them, the wilt caused by Fusarium oxysporum f.sp. ciceri is most destructive seed and soil borne disease. (Haware et al., 1986 which threatens successful cultivation of chickpea and causes severe losses in chickpea growing areas. (Grewal et al.,1974b and Singh et al.,1977. Different insecticides and herbicides were tried under in vitro, the insecticides Emamectin benzoate 5% SG, Imidachloprid 75% WP, Quinalphos 25% EC, Entrust 80% WP were used in three different concentrations. Among these highest per cent growth of inhibition of Fusarium oxysporum f.sp. ciceri was observed in Imidacloprid 0.3g (50.92% followed by Emamectin benzoate 0.05 mg (35.55%. The herbicides viz., Pendimethalin 30%EC, Imazathaphyr 10% SL, 2,4-D sodium salt 80%WP, Metsulfuron methyl 20% WG were used in three different concentrations, highest per cent growth of inhibition of Fusarium oxysporum f.sp. ciceri was observed in Pendimethalin 0.5ml (73.33%, followed by Pendimethalin 0.4ml (65.55%.

  18. Phylogenetic and recombination analysis of tomato spotted wilt virus.

    Directory of Open Access Journals (Sweden)

    Sen Lian

    Full Text Available Tomato spotted wilt virus (TSWV severely damages and reduces the yield of many economically important plants worldwide. In this study, we determined the whole-genome sequences of 10 TSWV isolates recently identified from various regions and hosts in Korea. Phylogenetic analysis of these 10 isolates as well as the three previously sequenced isolates indicated that the 13 Korean TSWV isolates could be divided into two groups reflecting either two different origins or divergences of Korean TSWV isolates. In addition, the complete nucleotide sequences for the 13 Korean TSWV isolates along with previously sequenced TSWV RNA segments from Korea and other countries were subjected to phylogenetic and recombination analysis. The phylogenetic analysis indicated that both the RNA L and RNA M segments of most Korean isolates might have originated in Western Europe and North America but that the RNA S segments for all Korean isolates might have originated in China and Japan. Recombination analysis identified a total of 12 recombination events among all isolates and segments and five recombination events among the 13 Korea isolates; among the five recombinants from Korea, three contained the whole RNA L segment, suggesting reassortment rather than recombination. Our analyses provide evidence that both recombination and reassortment have contributed to the molecular diversity of TSWV.

  19. Rhizobacteria induces resistance against Fusarium wilt of tomato by increasing the activity of defense enzymes

    Directory of Open Access Journals (Sweden)

    Hélvio Gledson Maciel Ferraz

    2014-09-01

    Full Text Available Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici (Fol, is one of the most important diseases that affect tomato yield worldwide. This study investigated the potential of three antagonists, Streptomyces setonii (UFV 618, Bacillus cereus (UFV 592 and Serratia marcescens (UFV 252, and as positive control the hormone jasmonic acid (JA, to reduce Fusarium wilt symptoms and to potentiate the defense enzymes in the stem tissues of tomato plants infected by Fol. The seeds were microbiolized with each antagonist, and the soil was also drenched with them. The plants were sprayed with JA 48 h before Fol inoculation. The area under the Fusarium wilt index progress curve was reduced by 54, 48, 47 and 45% for the UFV 618, JA, UFV 592 and UFV 252 treatments, respectively. The three antagonists, and even the JA spray, efficiently reduced the Fusarium wilt symptoms on the tomato plant stems, which can be explained by the lower malondialdehyde concentration (an indication of oxidative damage to lipids in the plasma membranes and the greater activities of peroxidases, polyphenoloxidases, glucanases, chitinases, phenylalanine ammonia-lyases and lipoxygenases, which are commonly involved in host resistance against fungal diseases. These results present a novel alternative that can be used in the integrated management of Fusarium wilt on tomatoes.

  20. Bacterial Modulation of Plant Ethylene Levels.

    Science.gov (United States)

    Gamalero, Elisa; Glick, Bernard R

    2015-09-01

    A focus on the mechanisms by which ACC deaminase-containing bacteria facilitate plant growth.Bacteria that produce the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, when present either on the surface of plant roots (rhizospheric) or within plant tissues (endophytic), play an active role in modulating ethylene levels in plants. This enzyme activity facilitates plant growth especially in the presence of various environmental stresses. Thus, plant growth-promoting bacteria that express ACC deaminase activity protect plants from growth inhibition by flooding and anoxia, drought, high salt, the presence of fungal and bacterial pathogens, nematodes, and the presence of metals and organic contaminants. Bacteria that express ACC deaminase activity also decrease the rate of flower wilting, promote the rooting of cuttings, and facilitate the nodulation of legumes. Here, the mechanisms behind bacterial ACC deaminase facilitation of plant growth and development are discussed, and numerous examples of the use of bacteria with this activity are summarized. PMID:25897004

  1. Effect Of Salinization On Fusarium Wilt Disease In Tomato Plant

    International Nuclear Information System (INIS)

    Salinization of soils or waters is one of the serious environmental problems in agriculture. It is necessary to determine the environmental factors under which the plants give higher yields and better quality to solve this problem. The problem of salinity is characterized by disruption in the physiological processes in plant which lead to shorting in growth and decrease in yield. The study was carried out to control fusarium disease in tomato plant irrigated with salt water (500, 1500, 15000, 45000 and 100000 ppm). These treatments lead to excess in malic and citric acids i.e. from 21 mmol/g fresh weight in control to 38.8 mmol/g fresh weight at 100000 ppm for citric acid while for malic acid, the value was increased from 1.4 mmol/g fresh weight for control to 2.1 mmol/g fresh weight. The excess of malic and citric acids lead to increase in acidity and vitamin C in tomato fruits. On the other side, the plant may adapt to this stress by increasing its proline content from 0.59 µmol/g fresh weight to 6.56 µmol/g fresh weight at 100000 and abscisic acid from 0.49 µmol/g fresh weight to 20.7 µmol/g fresh weight. The results showed that the fusarium fungal growth was observed till 100000 ppm but did not form sclerotia spores at 45000 ppm. On the other hand, the electrical conductivity was found to be 0.46, 2.3, 23.1, 69.2 and 153.8 dS/m for salinity levels of 500, 1500, 15000, 45000 and 100000 ppm, respectively. This study aimed to control the fusarium wilt disease by irrigating the plant with water has high salinity

  2. Selection for quantitative trait loci associated with resistance to Stewart's wilt in sweet corn.

    Science.gov (United States)

    Pataky, J K; Bohn, M O; Lutz, J D; Richter, P M

    2008-04-01

    The objectives of this research were to identify quantitative trait loci (QTL) for Stewart's wilt resistance from a mapping population derived from a sweet corn hybrid that is highly resistant to Pantoea stewartii and to determine if marker-based selection for those QTL could substantially improve Stewart's wilt resistance in a population derived from a cross of resistant lines and a highly susceptible sweet corn inbred. Three significant QTL for Stewart's wilt resistance on chromosomes 2 (bin 2.03), 5 (bin 5.03), and 6 (bin 6.06/6.07) explained 31% of the genetic variance in a population of 110 F(3:4) families derived from the sweet corn hybrid Bonus. The three QTL appeared to be additive in their effects on Stewart's wilt ratings. Based on means of families that were either homozygous or heterozygous for marker alleles associated with the resistance QTL, the QTL on chromosomes 2 and 6 appeared to have dominant or partially dominant gene action, while the QTL on chromosome 5 appeared to be recessive. A population of 422 BC(2)S(2) families was derived from crosses of a sweet corn inbred highly susceptible to Stewart's wilt, Green Giant Code 88 (GG88), and plants from two F(3:4) families (12465 and 12467) from the Bonus mapping population that were homozygous for marker alleles associated with Stewart's wilt resistance at the three QTL. Mean Stewart's wilt ratings for BC(2)S(2) families were significantly (P < 0.05) lower for families that were homozygous for the bnlg1902 marker allele (bin 5.03) from resistant lines 12465 or 12467 than for families that were heterozygous at this marker locus or homozygous for the bnlg1902 marker allele from GG88. Resistance associated with this QTL was expressed only if F(3:5) or BC(2)S(2) families were homozygous for marker alleles associated with the resistant inbred parent (P(1)). Marker alleles identified in the F(3:5) mapping population that were in proximity to the resistance QTL on chromosomes 2 and 6 were not polymorphic in

  3. Global Regulation of Virulence Determinants During Plant Colonization in the Bacterial Phytopathogen, Pantoea stewartii subsp. stewartii

    OpenAIRE

    Burbank, Lindsey

    2014-01-01

    Pantoea stewartii subsp. stewartii, the etiological agent of Stewart's wilt, is a bacterial pathogen of sweet corn which colonizes both the apoplast and xylem tissues. During the initial stages of the infection process, the pathogen forms water-soaked lesions through lysis of the plant cells, followed by colonization of the xylem tissue where it can grow to high cell densities and form biofilms. Biofilm formation within the xylem vessels can block water flow, causing the characteristic wiltin...

  4. Tomato spotted wilt virus glycoproteins exhibit trafficking and localization signals that are functional in mammalian cells

    NARCIS (Netherlands)

    Kikkert, M.; Verschoor, A.; Kormelink, R.; Rottier, P.; Goldbach, R.

    2001-01-01

    The glycoprotein precursor (G1/G2) gene of tomato spotted wilt virus (TSWV) was expressed in BHK cells using the Semliki Forest virus expression system. The results reveal that in this cell system, the precursor is efficiently cleaved and the resulting G1 and G2 glycoproteins are transported from th

  5. Screening of wild and cultivated Capsicum germplasm reveals new sources of Verticillium wilt resistance

    Science.gov (United States)

    Verticillium wilt caused by Verticillium dahliae is an important soilborne disease of pepper (Capsicum species) worldwide. Most commercial pepper cultivars lack resistance to this pathogen. Our objective was to identify resistance to multiple V. dahliae isolates in wild and cultivated Capsicum acces...

  6. Breeding and genetics of lettuce against race 2 of Verticillium wilt

    Science.gov (United States)

    Verticillium wilt, caused by the soil-borne fungus Verticillium dahliae, is a destructive disease of lettuce in California. Verticillium resistance 1 (Vr1) confers resistance to race 1 isolates but is defeated by race 2 isolates, which are predicted to increase in prevalence. Three Plant Introductio...

  7. Silage of white oat under nitrogen fertilization and pre-wilting

    Directory of Open Access Journals (Sweden)

    Gustavo Zamarchi

    2014-09-01

    Full Text Available The forage conservation as silage is a way to provide good quality forage during grazing scarcity periods, in this way, the objective was to evaluate the effect of pre-wilting and nitrogen fertilization on the fermentation characteristics and nutritive value of white oat silage, in two harvest stages. The experiment was conducted in 2011 at UTFPR, Dois Vizinhos-PR, Brazil. The experimental design was in a randomized blocks with two factorial arrangement and three replicates. The main treatments were six nitrogen doses: 0, 40, 80, 120, 160 and 200 kg ha-1, and secondary the stages of cutting for silage: early flowering with and without pre-wilting, and at blooming without pre-wilting. It was observed that nitrogen fertilization promoted a reduction in pH and mineral content of the silage, reducing fiber content and increasing crude protein content (CP, when made at oat early flowering. The effect of pre-wilting in early flowering inhibits the production of effluents and has higher levels of CP, without any effect on the fermentation and nutritional value. The silage at blooming stage features better standards of fermentation, with lower pH and buffering capacity, but with lower nutritional value.

  8. Mechanism of disease suppression of Fusarium wilt of watermelon by cover crop green manures

    Science.gov (United States)

    A fall planted Vicia villosa cover crop incorporated in spring as a green manure can suppress Fusarium wilt [Fusarium oxysporum f. sp. niveum (FON)] of watermelon in Maryland and Delaware. Experiments were conducted to determine whether the mechanism of this suppression was general or specific, and ...

  9. Cultivation of the Pine Wilt Nematode, Bursaphelenchus xylophilus, in Axenic Culture Media

    OpenAIRE

    Bolla, R. I.; Jordan, W

    1982-01-01

    The pine wilt nematode, Bursaphelenchus xylophilus, has been cultured axenically in vitro on soy peptone/yeast extract or modified Caenorhabditis medium supplemented with cholesterol and hemoglobin. Although growth, development and reproduction were best in soy peptone/yeast extract medium, satisfactory population size increases were observed in the chemically defined Caenorhaditis medium.

  10. The xylem as battleground for plant hosts and vascular wilt pathogens

    NARCIS (Netherlands)

    Yadeta, K.A.; Thomma, B.P.H.J.

    2013-01-01

    Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi, and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate a

  11. Occurrence of Tomato spotted wilt virus in Stevia rebaudiana and Solanum tuberosum in Northern Greece

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Lolas, P.

    2007-01-01

    Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Greece during 1972 (3) and currently is widespread in the central and northern part of the country infecting several cultivated and wild plant species (1,2). In June 2006, virus-like symptoms similar to th

  12. Purified tomato spotted wilt virus particles support both genome replication and transcription

    NARCIS (Netherlands)

    Knippenberg, van I.; Goldbach, R.W.; Kormelink, R.

    2002-01-01

    Purified Tomato spotted wilt virus particles were shown to support either genome replication or transcription in vitro, depending on the conditions chosen. Transcriptional activity was observed only upon addition of rabbit reticulocyte lysate, indicating a dependence on translation. Under these cond

  13. Analysis of the transcription initiation mechanism of tomato spotted wilt virus

    NARCIS (Netherlands)

    Duijsings, D.M.J.M.

    2001-01-01

    Genome replication and transcription of Tomato spotted wilt virus (TSWV, genus Tospovirus ) follows in most aspects the general rules for negative strand RNA viruses with segmented genomes. One common feature is the occurrence of "cap snatching" during transcription initiation. During this process,

  14. Regeneration of different plant functional types in a Masson pine forest following pine wilt disease.

    Directory of Open Access Journals (Sweden)

    Guang Hu

    Full Text Available Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs in Masson pine forests affected by pine wilt disease (PWD. Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1, deciduous woody species (PFT2, herbs (PFT3, and ferns (PFT4. We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation.

  15. Regeneration of different plant functional types in a Masson pine forest following pine wilt disease.

    Science.gov (United States)

    Hu, Guang; Xu, Xuehong; Wang, Yuling; Lu, Gao; Feeley, Kenneth J; Yu, Mingjian

    2012-01-01

    Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation. PMID:22563499

  16. Dynamics of genetic diversity of Tomato spotted wilt virus in the United States

    Science.gov (United States)

    Among known tospoviruses, Tomato spotted wilt virus (TSWV; genus Tospovirus, family Bunyaviridae) continues to be the major viral disease affecting a wide range of agricultural and horticultural crops worldwide. Like many other RNA viruses, TSWV is known to maintain heterogeneous and divergent popul...

  17. Tomato spotted wilt virus nucleocapsid protein interacts with both viral glycoproteins Gn and Gc in planta

    NARCIS (Netherlands)

    Ribeiro, D.M.O.G.; Borst, J.W.; Goldbach, R.W.; Kormelink, R.J.M.

    2009-01-01

    Recently, the Tomato Spotted Wilt Virus (TSWV) Gn and Gc glycoproteins were shown to induce the formation of (pseudo-) circular and pleomorphic membrane structures upon transient expression in plant cells. Furthermore, when singly expressed, Gc retains in the ER, while Gn is able to further migrate

  18. Comparison of ambrosia beetle communities in two host with laurel wilt: swampbay vs. avocado

    Science.gov (United States)

    The invasive redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of tre...

  19. Genome sequence of Fusarium oxysporum f. sp. melonis, a fungus causing wilt disease on melon

    Science.gov (United States)

    This manuscript reports the genome sequence of F. oxysporum f. sp. melonis, a fungal pathogen that causes Fusarium wilt disease on melon (Cucumis melo). The project is part of a large comparative study designed to explore the genetic composition and evolutionary origin of this group of horizontally ...

  20. APPLICATION OF PROPICONAZOLE IN MANAGEMENT OF LAUREL WILT DISEASE IN AVOCADO (Persea americana Mill.) TREES

    Science.gov (United States)

    Laurel wilt is a vascular disease of Lauraceous plants caused by a fungus (Raffaelea spp.) that is carried by a recently introduced, nonnative ambrosia beetle (Xyleborus glabratus). The disease is devastating to Persea species including redbay (Persea borbonia) and avocado (Persea americana) trees i...

  1. Genetic diversity studies and identification of SSR markers associated with Fusarium wilt (Fusarium udum) resistance in cultivated pigeonpea (Cajanus cajan)

    Indian Academy of Sciences (India)

    A. K. Singh; V. P. Rai; R. Chand; R. P. Singh; M. N. Singh

    2013-08-01

    Genetic diversity and identification of simple sequence repeat markers correlated with Fusarium wilt resistance was performed in a set of 36 elite cultivated pigeonpea genotypes differing in levels of resistance to Fusarium wilt. Twenty-four polymorphic sequence repeat markers were screened across these genotypes, and amplified a total of 59 alleles with an average high polymorphic information content value of 0.52. Cluster analysis, done by UPGMA and PCA, grouped the 36 pigeonpea genotypes into two main clusters according to their Fusarium wilt reaction. Based on the Kruskal–Wallis ANOVA and simple regression analysis, six simple sequence repeat markers were found to be significantly associated with Fusarium wilt resistance. The phenotypic variation explained by these markers ranged from 23.7 to 56.4%. The present study helps in finding out feasibility of prescreened SSR markers to be used in genetic diversity analysis and their potential association with disease resistance.

  2. Advances in Cotton Breeding for Resistance to Fusarium and Verticillium Wilt in the Last Fifty Years in China

    Institute of Scientific and Technical Information of China (English)

    JIAN Gui-liang; MA Cun; ZHENG Chuan-lin; ZOU Ya-fei

    2003-01-01

    This review summarizes the main advances in cotton breeding for resistance to fusarium andverticillium wilt in the last fifty years in China. The topics discussed include main achievements, experiences,problems and countermeasures for solving.

  3. Mortality due to Japanese oak wilt disease and surrounding forest compositions.

    Science.gov (United States)

    Oguro, Michio; Imahiro, Sawako; Saito, Shoichi; Nakashizuka, Tohru

    2015-12-01

    Japanese oak wilt (Raffaelea quercivora) is a vector-borne disease transmitted by the flying ambrosia beetle, Platypus quercivorus, and causes mass mortality in the fagaceous species of Japan. The data described in this article are available in Mendeley Data, DOI: 10.17632/xwj98nb39r.1 [1] and include the mortality status of 1089 Quercus crispula and 846 Quercus serrata trees and surrounding forest conditions. The findings using this dataset were published in M. Oguro, S. Imahiro, S. Saito, T. Nakashizuka, Relative importance of multiple scale factors to oak tree mortality due to Japanese oak wilt disease, For. Ecol. Manag. (2015) doi:10.1016/j.foreco.2015.07.016 [2]. PMID:26543883

  4. Mortality due to Japanese oak wilt disease and surrounding forest compositions

    Directory of Open Access Journals (Sweden)

    Michio Oguro

    2015-12-01

    Full Text Available Japanese oak wilt (Raffaelea quercivora is a vector-borne disease transmitted by the flying ambrosia beetle, Platypus quercivorus, and causes mass mortality in the fagaceous species of Japan. The data described in this article are available in Mendeley Data, DOI: 10.17632/xwj98nb39r.1 [1] and include the mortality status of 1089 Quercus crispula and 846 Quercus serrata trees and surrounding forest conditions. The findings using this dataset were published in M. Oguro, S. Imahiro, S. Saito, T. Nakashizuka, Relative importance of multiple scale factors to oak tree mortality due to Japanese oak wilt disease, For. Ecol. Manag. (2015 doi:10.1016/j.foreco.2015.07.016 [2].

  5. Thyme essential oil as a defense inducer of tomato against gray mold and Fusarium wilt.

    Science.gov (United States)

    Ben-Jabeur, Maissa; Ghabri, Emna; Myriam, Machraoui; Hamada, Walid

    2015-09-01

    The potential of thyme essential oil in controlling gray mold and Fusarium wilt and inducing systemic acquired resistance in tomato seedlings and tomato grown in hydroponic system was evaluated. Thyme oil highly reduced 64% of Botrytis cinerea colonization on pretreated detached leaves compared to untreated control. Also, it played a significant decrease in Fusarium wilt severity especially at7 days post treatment when it was reduced to 30.76%. To explore the plant pathways triggered in response to thyme oil, phenolic compounds accumulation and peroxidase activity was investigated. Plant response was observed either after foliar spray or root feeding in hydroponics which was mostly attributed to peroxidases accumulation rather than phenolic compounds accumulation, and thyme oil seems to be more effective when applied to the roots. PMID:26002413

  6. In vitro mutation induction for resistance to Fusarium wilt in the banana

    International Nuclear Information System (INIS)

    In Brazil, which is one of the world's principal banana production regions, almost all production is consumed within the country. Consumers show high preference for the cultivar Maca (AAB group). However, it is becoming increasingly difficult to produce bananas of this type because of their high susceptibility to Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense. Sexual breeding, which consists of recombination and selection, is limited in the banana because of polyploidy and sterility. Spontaneous somatic mutations are an important source of new cultirvars, and mutation breeding might be particularly important to generate genetic variation. Because of this, the mutation breeding approach has been used in Brazil. The objective of this research was to induce gamma ray mutations for resistance or to increase the level of tolerance to Fusarium wilt in the banana cultivar Maca on the basis of screening under field conditions. 4 refs

  7. An improved electrochemiluminescence polymerase chain reaction method for the detection of Fusarium wilts

    Institute of Scientific and Technical Information of China (English)

    Jie Wei; Xiao Ming Zhou

    2008-01-01

    An improved electrochemiluminescence polymerase chain reaction (ECL-PCR) method was developed and applied to detect Fusarium wilt. Briefly, the internal transcribed spacer (ITS) sequence of Fusarium oxysporum f. sp Cubense (FOC) was amplified by PCR. Two universal fragments, which were complimentary to Ru(bpy)32+ (TBR) labeled probe and Biotin labeled probe, respectively, were connected to the tail of primers so that all the PCR products got universal sequences. Then biotin labeled probes and TBR labeled probes were hybridized with the PCR products at the same time. Through the specific interaction between biotin and streptavidin, the PCR products were captured by streptavidin coated magnetic bead and then detected by ECL assay. The experiment results showed that the healthy banana samples and infected ones can be discriminated by this ECL-PCR method. This improved ECL-PCR approach is useful in Fusarium wilt detection due to its high sensitivity, simplicity and stability.

  8. Fermentation and Proteolysis During the Ensilage of Wilted and Unwilted Diploid and Tetraploid Red Clover

    Directory of Open Access Journals (Sweden)

    Cezary PURWIN

    2011-07-01

    Full Text Available The effects of the following factors were analyzed in the study: wilting degree, genetic form of red clover (2n – 4n, cultivars within the genetic form: 2n (Krynia, Parada, 4n (Jubilatka, Bona and DM x form, DM x 2n, DM x 4n. Fermentation and proteolysis during the ensilage of red clover were affected primarily by wilting, whereas genetic factors (genetic form, cultivar exerted a lesser effect. However, the genetic form of red clover affected the true protein content of silage and the extent of proteolysis during the ensiling process. The effect of the genetic form of red clover on the extent of proteolysis in silage (at similar levels of water-soluble carbohydrates and buffering capacity suggests that diploid and tetraploid red clover cultivars differ with respect to chemical properties (poliphenol oxidase activity, polyphenol content affecting proteolysis.

  9. Nematode Control Related to Fusarium Wilt in Soybean and Root Rot and Zinc Deficiency in Corn

    OpenAIRE

    Minton, N. A.; Parker, M. B.; Sumner, D. R.

    1985-01-01

    Nematode and disease problems of irrigated, double-cropped soybean and corn, and zinc deficiency of corn were investigated. Ethylene dibromide, phenamiphos, and aldicarb were equally effective for controlling nematodes and increasing yields of corn planted minimum-till and soybean planted in a moldboard plow prepared seedbed. The residual effects on yields of nematicides applied to the preceeding crop occurred during 3 years for soybean and 1 year for corn. Fusarium wilt symptoms of soybean t...

  10. Silage of white oat under nitrogen fertilization and pre-wilting

    OpenAIRE

    Gustavo Zamarchi; Paulo Sergio Pavinato; Luis Fernando Glasenapp Menezes; Thomas Newton Martin

    2014-01-01

    The forage conservation as silage is a way to provide good quality forage during grazing scarcity periods, in this way, the objective was to evaluate the effect of pre-wilting and nitrogen fertilization on the fermentation characteristics and nutritive value of white oat silage, in two harvest stages. The experiment was conducted in 2011 at UTFPR, Dois Vizinhos-PR, Brazil. The experimental design was in a randomized blocks with two factorial arrangement and three replicates. The main treatmen...

  11. Resistance screening trials on coconut varieties to Cape Saint Paul Wilt Disease in Ghana

    OpenAIRE

    Quaicoe Robert Nketsia; Dery Sylvester Kuuna; Philippe René; Baudouin Luc; Nipah Joseph Owusu; Nkansah-Poku Joe; Arthur Ransford; Dare Daniel; Yankey Egya Ndede; Pilet Fabian; Dollet Michel

    2009-01-01

    The Cape Saint Paul Wilt Disease (CSPWD) is a coconut lethal yellowing type disease (LY) and is the single most serious threat to coconut cultivation in Ghana. The recommended disease management strategy is the cultivation of disease-resistant coconut varieties. More than 38 varieties have been screened for their resistance to CSPWD since 1956 and the results are reviewed in this paper. Two varieties, Sri Lanka Green Dwarf (SGD) and Vanuatu Tall (VTT), have shown high resistance to the diseas...

  12. Use of additives and pre-wilting in Tifton 85 bermudagrass silage production

    OpenAIRE

    Marcela Abbado Neres; Paula Regina Hermes; João Paulo Ames; Maximilliane Alavarse Zambom; Deise Dalazen Castagnara; Leiliane Cristine de Souza

    2014-01-01

    The use of tropical grasses silage has become common in ruminant feed. An experiment was conducted to evaluate the fermentation characteristics, nutritional value, pH, fermentative capacity, ammonia nitrogen / total nitrogen (NH3N/total N) of Tifton 85 bermudagrass grass silage with different additives and wilting. The treatments were: pre-drying in the sun for two hours before silage, use of inoculant-enzymatic addition of soybean hulls, corn grits addition and use of salt in the surface lay...

  13. Role of the envelope glycoproteins in the infection cycle of tomato spotted wilt virus

    OpenAIRE

    Kikkert, M.

    1999-01-01

    Tomato spotted wilt virus (TSWV) forms the type member of the genus Tospovirus , which today harbors more than twelve different species. TSWV is able to infect an enormous variety of different plants, to which it often causes devastating effects, resulting in severe economical losses. Among the plant viruses, TSWV and the other tospoviruses form a distinct group. Taxonomically, they surprisingly do not belong to a plant virus family, but to a virus family which further consists of animal-infe...

  14. The Use of Antioxidants to Control Root Rot and Wilt Diseases of Pepper

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2010-06-01

    Full Text Available Ten isolates of Fusarium spp were isolated from pepper plants collected from different locations in New Valley Governorate, Egypt. Fusarium solani isolate FP2 and F. oxysporum isolate FP4 were highly pathogenic isolates but the other isolates moderate or less pathogenic to pepper plants (cv. Anaheim-M. The four antioxidant compounds (coumaric acid, citric acid, propylgalate and salicylic acid each at 100 and 200 ppm were evaluated for their in vitro and in vivo agonist to Fusarium pathogenic isolates caused root rot and wilt diseases in pepper plants. All tested antioxidant compounds reduced damping-off, root rot/wilt and area under root rot/wilt progress curve when used as seed soaking, seedling soaking, and soil drench especially at 200 ppm under greenhouse and field conditions compared with untreated plants. All chemicals increased fresh and dry weight of seedling grown in soil drenching or seed treatment with any antioxidants. At the same time, all tested chemicals significantly increase plant growth parameters i.e plant length, plant branching, and total yield per plant in case of seedling soaking or soil drench. In general, propylgalate at 200 ppm was more efficient in reducing infection with damping-off, root rot and wilt diseases as well as increasing the seedling fresh weight, dry weight, plant length, plant branching, number of pod plant-1 and pod yield plant-1. On the other hand, all tested antioxidants had less or no effect on mycelial dry weight and mycelial leaner growth. On the contrary, all chemicals much reduced spore formation in both Fusarium species at 100 or 200 ppm and the inhibitory effect of antioxidants increased with increasing their concentrations.

  15. Induced resistance to Fusarium wilt of banana by exogenous applications of indoleacetic acid

    OpenAIRE

    Fernández Falcón, Marino; Borges, Andrés A.; Borges-Pérez, Andrés

    2003-01-01

    Fusarium wilt of banana (Panama disease), caused by Fusarium oxysporum f.sp. cubense, is a soliborne systemic disease which occludes host vascular system. We report here two experiments on resistance induction with banana plants (cv. Dwarf Cavendish) carried out in glass greehouse with different indoleacetic acid treatments, which are capable of inducing resistance to Panama disease. The results obtained in these experiments suggest that the exogenous application of indoleacetic acid to banan...

  16. Induction of Systemic Resistance of Benzothiadiazole and Humic Acid in Soybean Plants Against Fusarium Wilt Disease

    OpenAIRE

    Montaser Fawzy ABDEL-MONAIM; Mamdoh Ewis ISMAIL; Morsy, Kadry Mohamed

    2011-01-01

    The ability of benzothiadiazole (BTH) and/or humic acid (HA) used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Alone and in combination the inducers were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations (Minia and New Valley governorates). The test...

  17. Efficacy of resistance selection to Verticillium wilt in strawberry (Fragaria x ananassa Duch.) tissue culture

    OpenAIRE

    Jadwiga I. Żebrowska

    2012-01-01

    The soil-borne pathogenic fungus Verticillium dahliae Kleb. causes economic losses in crops in temperate regions of the world and hence is the most studied species. Strawberry (Fragaria x ananassa Duch.) belongs to plant species susceptible to Verticillium dahliae, although the response to infection caused by this pathogen is varied and depends on the cultivar. Due to a lack of efficient methods in Verticillium wilt elimination, the selection of genetically resistant plant material is a prior...

  18. Herbicide-induced Resistance to Fusarium Wilt in Cotton and Gossypol Production of Host Cells

    OpenAIRE

    CANIHOŞ, Yeter

    2000-01-01

    Pretreating cotton seeds with some herbicidies used in cotton-growing areas of the Çukurova region markedly increased cotton resistance to Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum. Haloxyfob and linuron reduced the mycelial growth of the pathogen in both solid and liquid cultures. However, prometryn was more effective in plant development than linuron and haloxyfob. Synthesis of Phytoalexin gossypol was significantly produced in inoculated cotton plants compared with u...

  19. Routine mapping of Fusarium wilt resistance in BC1 populations of Arabidopsis thaliana

    OpenAIRE

    Andrew C Diener

    2013-01-01

    Abstract Background Susceptibility to Fusarium wilt disease varies among wild accessions of Arabidopsis thaliana. Six RESISTANCE TO FUSARIUM OXYSPORUM (RFO) quantitative trait loci (QTLs) controlling the resistance of accession Columbia-0 (Col-0) and susceptibility of Taynuilt-0 to Fusarium oxysporum forma specialis matthioli (FOM) are detected in a recombinant population derived from a single backcross of the F1 hybrid (BC1). In particular, ...

  20. Creation of Transgenic Bananas Expressing Human Lysozyme Gene for Panama Wilt Resistance

    Institute of Scientific and Technical Information of China (English)

    Xin-Wu PEI; Shi-Kai CHEN; Rui-Ming WEN; Shang YE; Jia-Qin HUANG; Yong-Qiang ZHANG; Bing-Shan WANG; Zhi-Xing WANG; Shi-Rong JIA

    2005-01-01

    Human lysozyme (HL) inhibits Fusarium oxysporum (FocR4) growth in vitro. To obtaintransgenic bananas (Musa spp.) that are resistant to Panama wilt (F. oxysporum), we introduced an HL genethat is driven by a constitutive cauliflower mosaic virus 35S promoter into the banana via Agrobacterium-mediated transformation. PCR confirmed that 51 transgenic plants were obtained. The development ofPanama wilt symptoms were examined after the plants had been grown in pots. The non-transgenic plantsdeveloped typical fusarium symptoms 60 d after FocR4 inoculation, whereas 24 of 51 transgenic plants remained healthy. The transgenic banana plants that showed resistance to FocR4 in the pots were then planted in a field that was heavily infected with FocR4 for further investigation. Eleven of 24 plants developed symptoms before bud emergence; another 11 plants showed symptoms after bud emergence and the remaining two plants, H-67 and H-144, remained healthy and were able to fruit. Northern blotting analysisdemonstrated that H-67 and H-144, bearing the strongest resistance to Panama wilt, had the highest level ofHL expression and that the expression of HL was well correlated with the FocR4 resistance of transgenicplants. We conclude that Agrobacterium-mediated transformation, with the assistance of particlebombardment, is a powerful approach for banana transformation and that a transgenic HL gene can causeresistance of the crop to FocR4 in the field.

  1. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-12-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  2. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

    Science.gov (United States)

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt. PMID:24808737

  3. Effects of soil application of fly ash on the fusarial wilt on tomato cultivars

    Energy Technology Data Exchange (ETDEWEB)

    Khan, M.R.; Singh, W.N. [Aligarh Muslim University, Aligarh (India). Dept. of Plant Protection, Rafi Ahmad Kidwai Institute of Agricultural Science

    2001-07-01

    A study was carried out in microplots to evaluate the effect of fly ash on the plant growth and yield of tomato cultivars, Pusa Ruby, Pusa Early Dwarf and New Uday, and on wilt disease caused by Fusarium oxysporum f. sp. lycopersici. Fly ash was applied to soil by broadcast or in rows at the rate of 1, 2, 3 and 4 kg ash m{sup -2} in place of inorganic fertilizers. In control plots, NPK (about 40 : 20 : 20 kg acre{sup -1}) and compost were added in place of fly ash. Ash application greatly increased the soil contents of P, K, B, Ca, Mg, Mn, Zn, carbonates, bicarbonates and sulphates. Plants grown in the ash-treated plots, especially at 3 or 4 kg dose, showed luxuriant growth and greener foliage, and plant growth and yield of the three cultivars were significantly increased in comparison with the plants grown in plots without fly ash. The wilt fungus, F. oxysporum f. sp. lycopersiciat the inoculum level of 2 g plant{sup -1} caused significant suppression of growth and yield in all three cultivars. Application of fly ash, however, checked the suppressive effect of the fungus, leading to a significant increase in the considered variables compared with the inoculated control. Soil population of the fungus gradually decreased with an increase in ash dose. Row application was found to be relatively more effective in enhancing the yield of tomato cultivars and suppressing the wilt disease.

  4. Biological control of chickpea wilt caused by fusarium oxysporum f.sp.ciceris

    International Nuclear Information System (INIS)

    This study was conducted in an attempt to control chickpea (Cicer arietinum L.) wilt, caused by fusarium oxysporum f.sp. ciceris, using antagonistic properties of soil microorganisms. It also aimed at avoiding problems resulting from the use of chemical fungicides. A trichoderma sp. was isolated from the rhizosphere of a resistant chickpea variety (ICCV-2) and a bacillus sp. from the rhizosphere and rhizoplane of the same variety. Both microorganisms proved to be effective in controlling the disease. In addition, trichoderma harzianum, which was obtained from Giza Research Station in Egypt, was also antagonistic to fusarium oxysporum f. sp. ciceris Wilt incidence was significantly reduced when chickpea was grown in posts containing soil mixed with any of the three antagonists or when chickpea seeds were initially treated with the seed-dressing fungicide vincit at 2 ml/kg seeds. Trichoderma harzianum proved to be the best bioagent as it gave the lowest disease incidence. In the field, the two trichoderma spp. were as effective as vincit in causing reduction in the wilt incidence. At the higher concentration of 140 g/m''2, the two antagonists were effective throughout the growth period, but they were less effective at the lower concentration of 70 g/m''2 particularly at the seedling stage.(Author)

  5. Plant growth hormones suppress the development of Harpophora maydis, the cause of late wilt in maize.

    Science.gov (United States)

    Degani, Ofir; Drori, Ran; Goldblat, Yuval

    2015-01-01

    Late wilt, a severe vascular disease of maize caused by the fungus Harpophora maydis, is characterized by rapid wilting of maize plants before tasseling and until shortly before maturity. The pathogen is currently controlled by resistant maize cultivars, but the disease is constantly spreading to new areas. The plant's late phenological stage at which the disease appears suggests that plant hormones may be involved in the pathogenesis. This work revealed that plant growth hormones, auxin (Indole-3-acetic acid) and cytokinin (kinetin), suppress H. maydis in culture media and in a detached root assay. Kinetin, and even more auxin, caused significant suppression of fungus spore germination. Gibberellic acid did not alter colony growth rate but had a signal suppressive effect on the pathogens' spore germination. In comparison, ethylene and jasmonic acid, plant senescing and defense response regulators, had minor effects on colony growth and spore germination rate. Their associate hormone, salicylic acid, had a moderate suppressive effect on spore germination and colony growth rate, and a strong influence when combined with auxin. Despite the anti-fungal auxin success in vitro, field experiments with dimethylamine salt of  2,4-dichlorophenoxyacetic acid (that mimics the influence of auxin) failed to suppress the late wilt. The lines of evidence presented here reveal the suppressive influence of the three growth hormones studied on fungal development and are important to encourage further and more in-depth examinations of this intriguing hormonal complex regulatory and its role in the maize-H. maydis interactions. PMID:25649030

  6. Changes and recovery of soil bacterial communities influenced by biological soil disinfestation as compared with chloropicrin-treatment

    OpenAIRE

    Mowlick, Subrata; Inoue, Takashi; Takehara, Toshiaki; Kaku, Nobuo; Ueki, Katsuji; Ueki, Atsuko

    2013-01-01

    Soil bacterial composition, as influenced by biological soil disinfestation (BSD) associated with biomass incorporation was investigated to observe the effects of the treatment on the changes and recovery of the microbial community in a commercial greenhouse setting. Chloropicrin (CP) was also used for soil disinfestation to compare with the effects of BSD. The fusarium wilt disease incidence of spinach cultivated in the BSD- and CP-treated plots was reduced as compared with that in the untre...

  7. Bacterial Vaginosis

    Science.gov (United States)

    ... 586. Related Content STDs during Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

  8. Bacterial Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Recommend on Facebook Tweet Share Compartir On this ... serious disease. Laboratory Methods for the Diagnosis of Meningitis This manual summarizes laboratory methods used to isolate, ...

  9. Prostatitis - bacterial

    Science.gov (United States)

    Any bacteria that can cause a urinary tract infection can cause acute bacterial prostatitis. Infections spread through sexual contact can cause prostatitis. These include chlamydia and gonorrhea . Sexually transmitted ...

  10. Bacterial Conjunctivitis

    OpenAIRE

    Köhle, Ülkü; Kükner, Şahap

    2003-01-01

    Conjunctivitis is an infection of the conjunctiva, generally characterized by irritation, itching, foreign body sensation, tearing and discharge. Bacterial conjunctivitis may be distinguished from other types of conjunctivitis by the presence of yellow–white mucopurulent discharge. It is the most common form of ocular infection all around the world. Staphylococcus species are the most common bacterial pathogenes, followed by Streptococcus pneumoniae and Haemophilus i...

  11. Bacterial carbonatogenesis

    International Nuclear Information System (INIS)

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The 'passive' carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The 'active' carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author)

  12. Effect of vinegar residue compost amendments on cucumber growth and Fusarium wilt.

    Science.gov (United States)

    Du, Nanshan; Shi, Lu; Du, Lantian; Yuan, Yinghui; Li, Bin; Sang, Ting; Sun, Jin; Shu, Sheng; Guo, Shirong

    2015-12-01

    Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen is one of the major destructive soilborne diseases and results in considerable yield losses. Methyl bromide was once the most effective disease control method but has been confirmed as harmful to the environment. Using suppressive media as biological controls to assist crop growth is becoming popular. In this study, Fusarium wilt of cucumber was successfully controlled by a newly identified suppressive media: vinegar residue compost-amended media (vinegar residue compost mixed with peat and vermiculite in a 6:3:1 ratio (v/v) vinegar residue substrate (VRS). Greenhouse experiments were carried out to evaluate the effect of VRS on the growth of cucumber seedlings and disease suppression. The control was peat/vermiculite (2:1, v/v). To identify the mixed media most suitable for the growth of plants and their suppressiveness indicators, we evaluated the biological characteristics of cucumber, the physicochemical and biochemical properties of the growth media, and the enzyme activities. Total organic C (C(org)), microbial biomass C (C(mic)), basal respiration (R(mic)), and enzyme (catalase, invertase, urease, proteinase, phosphatase, β-glucosidase, and hydrolysis of fluorescein diacetate) activities increased significantly after vinegar waste compost amendment. The compost media also showed a significantly positive effect on the growth of cucumber seedlings and the suppression of the disease severity index (DSI, 38% reduction). The cucumber rhizosphere population of F. oxysporum f. sp. cucumerinum (FOC) was significantly lower in VRS than in the control. These results demonstrate convincingly that vinegar residue compost-amended media has a beneficial effect on cucumber growth and could be applied as a method for biological control of cucumber Fusarium wilt. PMID:26250808

  13. Improved horticultural practices against leaf wilting, root rot and nutrient uptake in mango (mangiferaindica l.)

    International Nuclear Information System (INIS)

    Poor plant health condition due to various known biotic and abiotic stresses; becoming a disaster in each mango growing country of the world including Pakistan. On the basis of previous researches on the identification of pathogen and several abiotic factors; Soil drenching and foliar spray of various concentrations of Topsin M (TMIC), Aliette (ATP) and Ridomil Gold (ACE) in combination with CuSO/sub 4/(Copper sulphate) was done on mango plants of cv. S.B. (Samar Bahist) Chaunsa showing wilting of leaves and shoots. Foliar application of micro-nutrients (Fe, B and Zn) (Iron, Boron and Zinc) was also practiced to improve general health of experimental plants Month-wise emergence of flushes was significantly higher in all treated plants compared with control. Percentage of wilted leaves and root rot in plants, which received drenching and foliar treatments, was significantly reduced (50%) compared with untreated plants. Nitrogen, phosphorus and potassium (N, P and K) levels in leaves were significantly improved in treated plants compared with control. Sigmoid relatioship was observed between fungicides and copper sulphate concentrations and uptake of N, P and K in treated plants. Application of 250g ATP fungicide by foliar spray plus 125g by soil drench, each along with 50g CuSO/sub 4/proved to be the best against leaf wilting and it improved the N and P level in leaves. While, application of 250g TMIC by foliar spray and 125g by soil drench, each with 50g CuSO/sub 4/, was found to be the best to reduce the spread of root rot in experimental plants. Preliminary spray of TMIC along with Copper sulphate is effective to improve plant health of mango cv. S.B. Chounsa. (author)

  14. EFFECT OF DIFFERENT ORGANIC AMENDMENTS ON Fusarium oxysporum f.sp ciceri CAUSING CHICK PEA WILT

    OpenAIRE

    S.Ranjitha Rani; S.S.Mane

    2014-01-01

    Chickpea (Cicer arietinumL.) is one of the most important legumes grown in Asia. Though the area under this crop is more, the average yield per hectare is low because of several biotic and abiotic factors. Among them, the wilt caused by Fusarium oxysporumf.sp. ciceriis most destructive seed and soil borne disease. (Haware et al., 1986) which threatens successful cultivation of chickpea and causes severe losses in chickpea growing areas. (Grewal et al.,1974b and Singh et al.,1977.) The organic...

  15. Incidences and severity of vascular wilt in Acacia mangium plantations in Sabah, Malaysia

    Science.gov (United States)

    Maid, Mandy; Ratnam, Wickneswari

    2014-09-01

    This study aimed to evaluate the incidences and severity of vascular wilt disease associated with dieback in stands of commercial Acacia mangium plantations. The study revealed that the prevalence of the symptoms is high between 50 to 60% in two plantations, where it is found scattered in the plots that were surveyed. The incidence of the disease in each plot is low between 0 to 6%. The disease symptoms were more often found where the symptom syndrome in a chronic (level 3) or critical state (level 4). This suggests that the causal pathogen has the ability to penetrate into the tissues of the plants and only display symptoms at the latest stage.

  16. Effect of Compost Amendment on Soil Microbial Community and Pathogen Cansing Fusarium Wilt Disease of Spinach

    OpenAIRE

    Escuadra, Gina M. Edurise; Usami, Toshiyuki; Amemiya, Yoshimiki; 宇佐見, 俊行; 雨宮,良幹

    2008-01-01

    The effect of different composts on soil microflora, pathogen and the development of Fusarium wilt of spinach caused by Fusarium oxysporum f. sp. spinaciae, was assessed under three successive cultivations in the greenhouse. Composts of wheat bran, wheat bran and sawdust, coffee grounds, chicken manure and the mixture of composts with or without 5rabshell were applied into the infested soil at 5% (w/w) 30 days before the first cultivation and additional 2.5 0x1.56854bfff7acp-505fter the secon...

  17. Root and crown rot and wilt of tomatoes caused by fungal diseases in Ankara province.

    OpenAIRE

    Ozan, S.; Maden, S.

    2009-01-01

    This study was conducted in Ayaş, Beypazarı and Nallıhan districts of Ankara province during May-November 2003-2004 in order to detect fungal pathogens of tomato, and to find out the incidence, prevalence and occurrence times of these pathogens. It is detected that wilt and root rot pathogens causes important yield losses in tomato fields in Ankara. The incidences of the fungi isolated roots and crowns were 17.2 %, 0.96 %, 0.32 %, 0.91 %, 2.95 %,% 0.52 for Pyrenochaeta lycopersici, Fusa...

  18. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  19. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  20. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  1. IMPROVMENT BIOCONTROL OF DAMPING-OFF AND ROOT ROT/WILT OF FABA BEAN BY SALICYLIC ACID AND HYDROGEN PEROXIDE

    OpenAIRE

    Montaser F. Abdel-Monaim

    2013-01-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenici...

  2. Mapping crop diseases using survey data: The case of bacterial wilt in bananas in the East African highlands

    NARCIS (Netherlands)

    Bouwmeester, H.; Heuvelink, G.B.M.; Stoorvogel, J.J.

    2016-01-01

    Globally, crop diseases result in significant losses in crop yields. To properly target interventions to control crop diseases, it is important to map diseases at a high resolution. However, many surveys of crop diseases pose challenges to mapping because available observations are only proxies of t

  3. Reliability of diagnostic technigues for Clavibacter michiganensis subsp. michinanensis, the causal agent of bacterial wilt and canker of tomato

    Czech Academy of Sciences Publication Activity Database

    Kokošková, B.; Mráz, Ivan

    České Budějovice : Attavena, 2005 - (Bříza, J.; Pavingerová, D.; Špak, J.). s. 88 [Int. Symp. Ser. Recent Advances in Plant Biotechnology: From Laboratory to Business"/6./. 05.09.12-05.09.16, České Budějovice] Keywords : plant biotechnology Subject RIV: EE - Microbiology, Virology

  4. Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease.

    Science.gov (United States)

    Namukwaya, B; Tripathi, L; Tripathi, J N; Arinaitwe, G; Mukasa, S B; Tushemereirwe, W K

    2012-08-01

    Banana Xanthomonas wilt (BXW), caused by Xanthomonas campestris pv. musacearum, is one of the most important diseases of banana (Musa sp.) and currently considered as the biggest threat to banana production in Great Lakes region of East and Central Africa. The pathogen is highly contagious and its spread has endangered the livelihood of millions of farmers who rely on banana for food and income. The development of disease resistant banana cultivars remains a high priority since farmers are reluctant to employ labor-intensive disease control measures and there is no host plant resistance among banana cultivars. In this study, we demonstrate that BXW can be efficiently controlled using transgenic technology. Transgenic bananas expressing the plant ferredoxin-like protein (Pflp) gene under the regulation of the constitutive CaMV35S promoter were generated using embryogenic cell suspensions of banana. These transgenic lines were characterized by molecular analysis. After challenge with X. campestris pv. musacearum transgenic lines showed high resistance. About 67% of transgenic lines evaluated were completely resistant to BXW. These transgenic lines did not show any disease symptoms after artificial inoculation of in vitro plants under laboratory conditions as well as potted plants in the screen-house, whereas non-transgenic control plants showed severe symptoms resulting in complete wilting. This study confirms that expression of the Pflp gene in banana results in enhanced resistance to BXW. This transgenic technology can provide a timely solution to the BXW pandemic. PMID:22101927

  5. Comparative efficacy of different fungicides against fusarium wilt of chickpea (cicer arietinum l.)

    International Nuclear Information System (INIS)

    Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris (Foc) is the most serious and widespread disease of chickpea, causing a 100% loss under favorable conditions. Fourteen fungicides were evaluated against wilt pathogen In vitro with five different concentrations ranging from 1-10000 ppm. Among these only Carbendazim and Thiophanate-methyl was found as the most effective at all used concentrations. Other fungicides like Aliette, Nativo, Hombre-excel and Dividend star were found to be moderately effective. Whereas, remaining fungicides were ineffective against the targeted pathogen. Generally, a positive co-relation was observed between increasing concentrations of the tested fungicides and inhibition of Foc. Based on In vitro results Carbendazim, Thiophanate-methyl, Aliette, Dividend-star, Hombre-excel, Score and Nativo were selected for pot and field experiments. The higher concentrations of the few fungicides completely inhibited the pathogen as well as found to be phytotoxic and suppressed the plant growth while lower concentrations promoted the growth of chickpea plants. On over all bases, the Carbendazim and Thiophanate-methyl, followed by Aliette and Nativo were more effective in reducing the impact of pathogen as well as enhancing the plant growth in greenhouse experiment. Under field conditions, all fungicides except Score remarkably decreased the disease development and subsequently increased the plant growth as well as grain yield as compared to untreated plants. (author)

  6. VEGETATIVE COMPATIBILITY GROUPS OF FUSARIUM OXYSPORUM, THE CAUSAL ORGANISM OF VASCULAR WILT ON ROSELLE IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    K.H. Ooi

    1999-01-01

    Full Text Available Forty strains of Fusarium oxysporvm isolated from roselle (Hibiscus sabdariffa var. sabdariffa showing vascular wilt symptoms in three states (Terengganu, Penang and Ipoh in the northern Malaysian Peninsula were used to investigate the vegetative co mpatibility. Nitrate-nonutilizing (nil mutants were recovered from all the strains tested and subsequently used to study vegetative compatibility groups (VCG within the population by nit mutants pairings on minimal medium. Thirteen VCGs were found and none were vegetatively compatible with those of other formae speciales (f. spp. such as asparagi and cubense, and non-pathogenic strains from paddy and oil palm. The results indicate that there is substantial genetic diversity in F. oxysporum that causes vascular wilt disease on roselle as reflected by multiple VCGs, but the distribution of strains into the VCGs is not even as there are 26 representatives in VCG-1001M, two in VCG-1003M and VCG-1013M and only one in the other VCGs. This study may provide new insight into the establishment of a new forma specialis off. oxysporum.

  7. Induction of systemic resistance of benzothiadiazole and humic Acid in soybean plants against fusarium wilt disease.

    Science.gov (United States)

    Abdel-Monaim, Montaser Fawzy; Ismail, Mamdoh Ewis; Morsy, Kadry Mohamed

    2011-12-01

    The ability of benzothiadiazole (BTH) and/or humic acid (HA) used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Alone and in combination the inducers were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations (Minia and New Valley governorates). The tested treatments significantly reduced damping-off and wilt diseases and increased growth parameters, except the number of branches per plant and also increased seed yield. Application of BTH (0.25 g/L) + HA (4 g/L) was the most potent in this respect. Soybean seed soaking in BTH + HA produced the highest activities of the testes of oxidative enzymes followed by BTH in the four soybean cultivars. HA treatment resulted in the lowest increases of these oxidative enzymes. Similar results were obtained with total phenol but HA increased total phenol more than did BTH in all tested cultivars. PMID:22783118

  8. Characterization of Novel Trichoderma asperellum Isolates to Select Effective Biocontrol Agents Against Tomato Fusarium Wilt.

    Science.gov (United States)

    El Komy, Mahmoud H; Saleh, Amgad A; Eranthodi, Anas; Molan, Younes Y

    2015-03-01

    The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and β-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their anta- gonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents. PMID:25774110

  9. New Lines of Chickpea Against Fusarium Oxysporum f. sp. Ciceris Wilt

    Directory of Open Access Journals (Sweden)

    Rosa M. Arvayo-Ortiz

    2012-01-01

    Full Text Available Problem statement: In Mexico, 70 and 20% of chickpea is produced in Sinaloa and Sonora, respectively. In Sonora wilting by Fusarium Oxysporum f. sp. Ciceris (FOC causes losses of up to 60%, while in other parts of the world ranged from 12-15% annually. The aim of this study was to evaluate the resistance of new lines of chickpea obtained through breeding programs against FOC wilt. Approach: In order to evaluate the resistance of new chickpea lines: Hoga-012, Hoga-490-2 and Hoga-508, including the two most important commercial cultivars in Mexico: Blanco Sinaloa-92 and Costa-2004 and as control two cultivars: JG-62 (susceptible and WR-315 (resistant, a pathogen city test was performed with races 0 and 5 of FOC. Plants were evaluated based on leaf and root damage during 50 days, using a hedonic scale of five levels (0-4. Results: New chickpea lines as well as commercial cultivars were susceptible to races 0 and 5 of FOC. Changes (PConclusion: New lines of chickpea and commercial cultivars did not show resistance to FOC races isolated in chickpea fields of Sonora. Thus, it should be continued in the search for resistant genotypes through breeding programs to assist in controlling the disease.

  10. "Candidatus Phytoplasma americanum", a phytoplasma associated with a potato purple top wilt disease complex.

    Science.gov (United States)

    Lee, Ing-Ming; Bottner, Kristi D; Secor, Gary; Rivera-Varas, Viviana

    2006-07-01

    Potato purple top wilt (PPT) is a devastating disease that occurs in various regions of North America and Mexico. At least three distinct phytoplasma strains belonging to three different phytoplasma groups (16SrI, 16SrII and 16SrVI) have been associated with this disease. A new disease with symptoms similar to PPT was recently observed in Texas and Nebraska, USA. Two distinct phytoplasma strain clusters were identified. One belongs to the 16SrI phytoplasma group, subgroup A, and the other is a novel phytoplasma that is most closely related to, and shares 96.6 % 16S rRNA gene sequence similarity with, a member of group 16SrXII. Phylogenetic analysis of 16S rRNA gene sequences of the novel PPT-associated phytoplasma strains, previously described 'Candidatus Phytoplasma' organisms and other distinct unnamed phytoplasmas indicated that the novel phytoplasma, termed American potato purple top wilt (APPTW) phytoplasma, represents a distinct lineage and shares a common ancestor with stolbur phytoplasma, "Candidatus Phytoplasma australiense", "Candidatus Phytoplasma japonicum", "Candidatus Phytoplasma fragariae", bindweed yellows phytoplasma (IBS), "Candidatus Phytoplasma caricae" and "Candidatus Phytoplasma graminis". On the basis of unique 16S rRNA gene sequences and biological properties, it is proposed that the APPTW phytoplasma represents "Candidatus Phytoplasma americanum", with APPTW12-NE as the reference strain. PMID:16825635

  11. Screening, selection and evaluation of irradiation-induced mutants of spearmint for resistance to Verticillium wilt

    International Nuclear Information System (INIS)

    Rhizomes of 'Scotch' spearmint (Mentha cardiaca var. Scotch) were irradiated with gamma rays to induce mutations for resistance to Verticillium wilt. All primary, most secondary, and many tertiary shoots that grew from irradiated rhizomes were inoculated by immersing their cut ends in a spore suspension (5x105 spores/ml) of a virulent isolate of Verticillium dahliae. Intense selection pressure was obtained by using controlled inoculations and ideal conditions for disease development. Selections received a second, and sometimes a third vegetative cycling, inoculation and selection. From these greenhouse tests, 19 selections showing resistance were field-tested in 1975, and an additional 141 selections were field-tested in 1976 at two locations heavily inoculated with V. dahliae. Several selections were highly resistant at both locations in 1976. Many selections contained obviously mixed resistant and susceptible individuals and some selections were infected on only one side of the plant, indicating their chimeral nature. Possibly two or three pure mutants for wilt resistance have been identified. (author)

  12. Screening of ten advanced chickpea lines for blight and wilt resistance

    International Nuclear Information System (INIS)

    Ten advanced chickpea lines developed at NIAB were screened for resistance to Ascochyta blight and Fusarium wilt diseases in different sets of experiments conducted under controlled environment. Inoculation of plants by spore suspension of virulent strains of Ascochyta rabiei revealed that one line (97313) was resistant tolerant, two lines (97305, 97392) were tolerant, six lines (97306, 97310, 97311, 97303, 97302, 97393) were tolerant/susceptible and one line (97301) was susceptible. Screening of the same lines against Fusarium wilt by water culture method showed that two lines (97301, 97313) were moderately resistant, four lines (97302, 97303, 97306, 97393) were tolerant and the remaining four lines were susceptible. Screening through phytotoxic culture filtrates revealed that two lines (97302, 97313) were less sensitive to culture filtrates of Ascochyta rabiei and Fusarium oxysporum than the resistant check (CM88). These lines were also analyzed spectrophotometrically for peroxidase enzyme activity. Maximum enzyme activity was detected after 48 hours of inoculation with A. rabiei in three lines (97305, 97311, 97313) and resistant check (CM88) while enzyme activity in the remaining lines reached its maximum after 72 hours of inoculation which was comparable to the susceptible check (Pb-1). These studies lead to the conclusion that one line (97313) exhibited resistance against both the diseases and can be used as a source of resistance for further improvement of chickpea germplasm. (author)

  13. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  14. Quantitative trait locus analysis of Verticillium wilt resistance in an introgressed recombinant inbred population of Upland cotton

    Science.gov (United States)

    Verticillium wilt (VW) of Upland cotton (Gossypium hirsutum L.) is caused by the soil-borne fungal pathogen Verticillium dahlia Kleb. The availability of VW-resistant cultivars is vital for control of this economically important disease, but there is a paucity of Upland cotton breeding lines and cul...

  15. Control of wilt disease of lentil through bio control agents and organic amendments in Tarai region of Uttarakhand, India.

    Science.gov (United States)

    Garkoti, Ankita; Kumar, Vijay; Tripathi, H S

    2014-11-01

    The present work aimed at evaluating the efficacy of bioagents and organic amendments against lentil wilt pathogen. Field trials were carried out consecutively during Rabi 2010-11 and 2011-12 crop seasons in Randomized Block Design (RBD) with three replications, using 'Pant L-639' a popular cultivar. The plot size was 3.0 x 1.5 m2 with row spacing of 30 cm. Effect of selected bioagents and organic amendments on disease incidence, 1000 grain weight and yield kg ha' of lentil was recorded. It was observed that seed treatment with Trichoderma harizanum + Pseudomonas fluorescens significant by reduced 1.73% (2010-11) and 1.93% (2011-12) in Fusarium wilt disease incidence and increase in grain yield 507.6 kg ha(-1) and 496.0 kg ha(-1) respectively during both crop seasons. Among organic amendments, minimum wilt disease incidence of 1.69% (2010-11) and 1.81% (2011-12) and maximum grain yield 496.3 kg ha(-1) (2010-11) and 484.0 kg ha(-1) (2011-12) were observed in farm yard manure + spent compost treated plots. This indicates that these treatments have important roles in biologically based management strategies for controling Fusarium wilt disease under organic mode of lentil cultivation in Uttarakhand State. PMID:25522507

  16. Race 3, a new and highly virulent race of Fusarium oxysporum f. sp. niveum causing Fusarium wilt in watermelon

    Science.gov (United States)

    Three races (0, 1, and 2) of Fusarium oxysporum f. sp. niveum have been previously described in watermelon (Citrullus lanatus) based on their ability to cause disease on differential watermelon genotypes. Four isolates of F. oxysporum f. sp. niveum collected from wilted watermelon plants or infeste...

  17. Fifteen years of verticillium wilt of lettuce in america’s salad bowl: a tale of immigration, subjugation and abatement.

    Science.gov (United States)

    Lettuce is a popular leafy vegetable that is globally cultivated. The US ranks second in production, with coastal California producing half of the US supply. In 1995, Verticillium wilt caused by the soil borne fungus Verticillium dahliae was identified as a disease of lettuce in coastal California, ...

  18. Draft Genome Sequence of Raffaelea quercivora JCM 11526, a Japanese Oak Wilt Pathogen Associated with the Platypodid Beetle, Platypus quercivorus

    Science.gov (United States)

    Manabe, Ri-ichiroh; Ohkuma, Moriya; Endoh, Rikiya

    2016-01-01

    The Japanese oak wilt pathogen Raffaelea quercivora and the platypodid beetle, Platypus quercivorus, cause serious mass mortality of Quercus spp. in Japan. Here, we present the first draft genome sequence of R. quercivora JCM 11526 to increase our understanding of the mechanism of pathogenicity and symbiosis with the ambrosia beetle. PMID:27469944

  19. Screening of chickpea advanced lines for sources of resistance against blight and wilt two major diseases of chickpea

    International Nuclear Information System (INIS)

    Chickpea (Cicer arietinum L.) an important food legume, ranks third in the world. In Pakistan yield of chickpea is low due to the prevalence of wilt and blight diseases - the two destructive diseases. The control measures available are not feasible and economical, except to exploit host plant resistance mechanism to identify the sources of resistance in existing chickpea germplasm. Fifty four advance chickpea genotypes were screened in blight screening nursery and wilt sick plot. Out of total 54 genotypes 23 were resistant and 16 were moderately resistant to Ascochyta blight disease. Among 23 resistant genotypes; K0058-09, K0062-09, K0066-09, D095-09, K07A005, BK05A015 and BK04A013 had disease rating mean of 3. The results of early wilt showed 19 genotypes as highly resistant and 15 as resistant. The genotypes K0070-09, BKK17106, CH 65/02 and BK04A013 were highly susceptible to wilt during early pathogen infection at seedling stage while the genotypes K0063-09, BKK17106 and BK04A013 were susceptible during late season. Resistance sources identified could be exploited directly and also may be transferred through hybridization to high yielding disease susceptible genotypes. (author)

  20. Redbay ambrosia beetle/Laurel wilt: Overview of projects at the USDA-ARS Subtropical Horticulture Research Station

    Science.gov (United States)

    ABSTRACT Laurel wilt, a deadly fungal disease of avocado and other trees in the Lauraceae, is vectored by the redbay ambrosia beetle (Xyleborus glabratus). First detected near Savannah, GA in 2002, the beetle and its obligatory pathogen have since spread to South Carolina and Florida. Currently, t...

  1. Detection and management of Xyleborus glabratus and other vectors of laurel wilt, a lethal disease affecting avocados in Florida

    Science.gov (United States)

    The redabay ambrosia beetle, Xyleborus glabratus, carries a phytopathogenic symbiont, Raffaelea lauricola, which causes laurel wilt, a lethal vascular disease of some Lauraceae species. Both X. glabratus and R. lauricola are natives of Asia that recently invaded much of the coastal plain of the sout...

  2. Responses of nitrogen metabolism and seed nutrition to drought stress in soybean genotypes differing in slow-wilting phenotype

    Directory of Open Access Journals (Sweden)

    Nacer eBellaloui

    2013-12-01

    Full Text Available Recent advances in soybean breeding have resulted in genotypes that express the slow-wilting phenotype (trait under drought stress conditions. The physiological mechanisms of this trait remain unknown due to the complexity of trait × environment interactions. The objective of this research was to investigate nitrogen metabolism and leaf and seed nutrients composition of the slow-wilting soybean genotypes under drought stress conditions. A repeated greenhouse experiment was conducted using check genotypes: NC-Roy (fast wilting, Boggs (intermediate in wilting; and NTCPR94-5157 and N04-9646 (slow-wilting, SLW genotypes. Plants were either well-watered or drought stressed. Results showed that under well-watered conditions, nitrogen fixation (NF, nitrogen assimilation (NA, and leaf and seed composition differed between genotypes. Under drought stress, NF and NA were higher in NTCPR94-5157 and N04-9646 than in NC-Roy and Boggs. Under severe water stress, however, NA was low in all genotypes. Leaf water potential was significantly lower in checks (-2.00 MPa than in the SLW genotypes (-1.68 MPa. Leaf and seed concentrations of K, P, Ca, Cu, Na, B were higher in SLW genotypes than in the checks under drought stress conditions. Seed protein, oleic acid, and sugars were higher in SLW genotypes, and oil, linoleic and linolenic acids were lower in SLW genotypes. This research demonstrated that K, P, Ca, Cu, Na, and B may be involved in SLW trait by maintaining homeostasis and osmotic regulation. Maintaining higher leaf water potential in NTCPR94-5157 and N04-9646 under drought stress could be a possible water conservation mechanism to maintain leaf turgor pressure. The increase in osmoregulators such as minerals, raffinose and stachyose, and oleic acid could be beneficial for soybean breeders in selecting for drought stress tolerance.

  3. Analyses of Fusarium wilt race 3 resistance in Upland cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Abdullaev, Alisher A; Salakhutdinov, Ilkhom B; Egamberdiev, Sharof Sh; Kuryazov, Zarif; Glukhova, Ludmila A; Adilova, Azoda T; Rizaeva, Sofiya M; Ulloa, Mauricio; Abdurakhmonov, Ibrokhim Y

    2015-06-01

    Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represents a serious threat to cotton (Gossypium spp.) production. For the last few decades, the FOV pathogen has become a significant problem in Uzbekistan causing severe wilt disease and yield losses of G. hirsutum L. cultivars. We present the first genetic analyses of FOV race 3 resistance on Uzbek Cotton Germplasm with a series of field and greenhouse artificial inoculation-evaluations and inheritance studies. The field experiments were conducted in two different sites: the experimental station in Zangiota region-Environment (Env) 1 and the Institute of Cotton Breeding (Env-2, Tashkent province). The Env-1 was known to be free of FOV while the Env-2 was known to be a heavily FOV infested soil. In both (Env-1 and Env-2) of these sites, field soil was inoculated with FOV race 3. F2 and an F3 Upland populations ("Mebane B1" × "11970") were observed with a large phenotypic variance for plant survival and FOV disease severity within populations and among control or check Upland accessions. Wilt symptoms among studied F2 individuals and F3 families significantly differed depending on test type and evaluation site. Distribution of Mendelian rations of susceptible (S) and resistant (R) phenotypes were 1S:1R field Env-1 and 3S:1R field Env-2 in the F2 population, and 1S:3R greenhouse site in the F3 population. The different segregation distribution of the Uzbek populations may be explained by differences in FOV inoculum level and environmental conditions during assays. However, genetic analysis indicated a recessive single gene action under high inoculum levels or disease pressure for FOV race 3 resistance. Uzbek germplasm may be more susceptible than expected to FOV race 3, and sources of resistance to FOV may be limited under the FOV inoculum levels present in highly-infested fields making the breeding process more complex. PMID:25896369

  4. Possible involvement of eEF1A in Tomato spotted wilt virus RNA synthesis.

    Science.gov (United States)

    Komoda, Keisuke; Ishibashi, Kazuhiro; Kawamura-Nagaya, Kazue; Ishikawa, Masayuki

    2014-11-01

    Tomato spotted wilt virus (TSWV) is a negative-strand RNA virus in the family Bunyaviridae and propagates in both insects and plants. Although TSWV can infect a wide range of plant species, host factors involved in viral RNA synthesis of TSWV in plants have not been characterized. In this report, we demonstrate that the cell-free extract derived from one of the host plants can activate mRNA transcriptional activity of TSWV. Based on activity-guided fractionation of the cell-free extract, we identified eukaryotic elongation factor (eEF) 1A as a possible host factor facilitating TSWV transcription and replication. The RNA synthesis-supporting activity decreased in the presence of an eEF1A inhibitor, suggesting that eEF1A plays an important role in RNA synthesis of TSWV. PMID:25151062

  5. Resistance screening trials on coconut varieties to Cape Saint Paul Wilt Disease in Ghana

    Directory of Open Access Journals (Sweden)

    Quaicoe Robert Nketsia

    2009-03-01

    Full Text Available The Cape Saint Paul Wilt Disease (CSPWD is a coconut lethal yellowing type disease (LY and is the single most serious threat to coconut cultivation in Ghana. The recommended disease management strategy is the cultivation of disease-resistant coconut varieties. More than 38 varieties have been screened for their resistance to CSPWD since 1956 and the results are reviewed in this paper. Two varieties, Sri Lanka Green Dwarf (SGD and Vanuatu Tall (VTT, have shown high resistance to the disease, and their hybrid (SGD × VTT is under observation to determine its performance. A programme to rehabilitate the CSPWD-devastated areas was started in 1999. Emerging results indicate that the MYD × VTT hybrid being used for the programme, succumbs to the disease under intense disease pressure. A redirection of the rehabilitation programme and the screening of more varieties are recommended.

  6. Cape Saint Paul Wilt Disease of coconut in Ghana: surveillance and management of disease spread

    Directory of Open Access Journals (Sweden)

    Nkansah-Poku Joe

    2009-03-01

    Full Text Available The Cape Saint Paul Wilt Disease (CSPWD, a lethal-yellowing type disease of coconut has been in Ghana since 1932. Aerial and/or ground surveys were undertaken to assess the current status of the disease spread. The survey showed that the spread of the disease for the past 5 years has mainly been the expansion of existing foci. However, new outbreaks were identified at Glidzi in the Volta, Bawjiase and Efutu Breman in Central regions. After the resurgence in the Volta region in 1995, the Woe-Tegbi-Dzelukope corridor has remained endemic, but less aggressive. Pockets of healthy groves remain along all the coastline and inland of known disease zones. Eradication of diseased palms at Ampain focus lying just about 60 km to the Ivorian border, and disease situations on new replanting with MYD × VTT hybrid are discussed.

  7. 海洋细菌AiL3菌株防治香蕉枯萎病研究%Biological Control of Banana Fusarium Wilt by Marine Bacterium AiL3

    Institute of Scientific and Technical Information of China (English)

    张萌; 唐桢强; 何红; 谢江辉

    2013-01-01

    The indoor experiment and field test of Marine bacterium AiL3 were carried out to study the effect on the suppression of the banana Fusarium-wilt disease and the growth of banana seedlings. The results showed that the number of leaves, the plant height, photosynthetic rate and transpiration rate of the tested banana plants were promoted significantly after innoculated with strain AiL3 in indoor and field tests compared to the control treatment. The control efficacies of AiL3 against Fusarium Wilt was 100% with the test indoor for six months. The control efficacies were 72.71% and 46.32% after 8 months with the indoor test and field test, respectively. It was suggested that the bacterial strain AiL3 could control the banana Fusarium wilt and promote growth of banana.%采用室内盆栽和大田小区试验对海洋细菌AiL3菌株防治香蕉枯萎病作用及对香蕉的促生效果进行测定.结果表明:菌株处理后盆栽试验和大田试验中的香蕉苗叶片数、株高、光合速率和蒸腾速率等均明显高于对照;AiL3菌株盆栽试验处理6个月后对香蕉枯萎病的防治效果达100%,大田小区试验菌株处理8个月后对香蕉枯萎病的防治效果分别为72.71%和46.32%.表明AiL3菌株对香蕉植株有一定的防病促生作用.

  8. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  9. Effects on controlling banana Fusarium wilt by bio-fertilizer,chitosan,hymexazol and their combinations%生物肥与甲壳素和恶霉灵配施对香蕉枯萎病的防治效果

    Institute of Scientific and Technical Information of China (English)

    张志红; 彭桂香; 李华兴; 蔡燕飞; 张新明; 赵兰凤

    2011-01-01

    The control effect of banana Fusarium wilt (Fusarium oxysporum f. sp. cubense, Foc )by bio-fertilizer (F),chitosan degrading liquid ( C), hymexazol (H) and their combinations was studied. The soil bacterial community diversity was investigated by Biolog Eco plate and T-RFLP techniques under pot experiment. The results showed that banana Fusarium wilt index in the treatment of the combination of bio-fertilizer and hymexazol ( H + F) was the highest, and the lowest in the combination of bio-fertilizer and chitosan degrading liquid( C + F), compared with the sterilized bio-fertilizer treatment(CK). The control effect of C + F treatment was 42.0%, higher than that of single bio-fertilizer ( 32.8% ).However, The treatment of H + F increased the severity of Fusarium wilt. The average well color development (AWCD) in Biolog plate indicated the ability of carbon utilization of microbial communities, while the indices of Shannon, Smipson and McIntosh were calculated to show the richness, dominance and evenness of the functional diversity. The changes of AWCD and diversity indices (including to Shannon H, Simpson D, Mcintosh U) were negatively correlated with the control effect in different treatments. The better effect of controlling disease showed the lower microbial diversity indices in soils, which further studied by the comparison of AWCD in three samples, including the soil (S), banana pathogenic fungi (Foc) and the mixture of soil and banana pathogenic fungi ( S +Foc) by Biolog Eco plate and bacterial identification plate ( patent publication number: CN101200755). The results suggested that the pathogenic fungal Fcc utilized some carbon substrates well in two plates, which interfered the final color reaction. Therefore, the type and population of pathogens may be considered in the determination of the soil bacterial community functional diversity by Biolog plate. T-RFLP results demonstrated that the number of terminal restriction fragments (TRFs) was the lowest in

  10. ±Genetic structure of the oak wilt vector beetle Platypus quercivorus: inferences toward the process of damaged area expansion

    Directory of Open Access Journals (Sweden)

    Nozaki Ai

    2010-10-01

    Full Text Available Abstract Background The ambrosia beetle, Platypus quercivorus, is the vector of oak wilt, one of the most serious forest diseases in Japan. Population genetics approaches have made great progress toward studying the population dynamics of pests, especially for estimating dispersal. Knowledge of the genetic structuring of the beetle populations should reveal their population history. Using five highly polymorphic microsatellite loci, 605 individuals from 14 sampling sites were assessed to infer the ongoing gene flow among populations as well as the processes of expansion of damaged areas. Results Population differentiation (FST = 0.047, G'ST = 0.167 was moderate and two major clusters were detected by several methods, dividing the samples into north-eastern and south-western populations, a similar genetic divergence was reported in host oak trees. Within the north-eastern populations, the subgroups mostly corresponded to differences in the collection period. The genetic characteristics of the population might have changed after 2 years due to the mixing of individuals between populations with enhanced migration related to population outbreaks. Because isolation by distance was detected for whole populations and also within the north-eastern populations, migration was considered to be limited between neighbouring populations, and most populations were suggested to be in genetic equilibrium of genetic drift and gene flow. Recent bottlenecks were found in some populations with no geographical bias; however, they were all from newly emerged oak wilt forests. The emergence of oak wilt should have induced intense fluctuations in the beetle population size. Conclusions Because the genetic boundaries coincide, we suggest that the geographical structuring of the beetle was formed by co-evolution with the host species. Our findings indicate the oak wilt expansion process.

  11. ±Genetic structure of the oak wilt vector beetle Platypus quercivorus: inferences toward the process of damaged area expansion

    OpenAIRE

    Nozaki Ai; Okada Mitsuhiro; Saito Shoichi; Shoda-Kagaya Etsuko; Nunokawa Kouichi; Tsuda Yoshiaki

    2010-01-01

    Abstract Background The ambrosia beetle, Platypus quercivorus, is the vector of oak wilt, one of the most serious forest diseases in Japan. Population genetics approaches have made great progress toward studying the population dynamics of pests, especially for estimating dispersal. Knowledge of the genetic structuring of the beetle populations should reveal their population history. Using five highly polymorphic microsatellite loci, 605 individuals from 14 sampling sites were assessed to infe...

  12. Efficacy of Micro Nutrients on Banana fusarium Wilt. (Fusarium oxysporum f. sp. cubense) and it's Synergistic Action with Trichoderma viride

    OpenAIRE

    K. SANJEEV; Eswaran, A.

    2008-01-01

    In the present investigations, efficacy of micro nutrients viz., (calcium nitrate, ammonium sulphate, copper sulphate, potassium chloride, sodium chloride, borax, ferrous sulphate and zinc sulphate) against Fusarium oxysporum f. sp. cubense causing panama wilt of banana were studied. The results of experiment revealed that among the micro nutrients used, borax @ 500 and 750 ppm completely inhibited the mycelial growth of Fusarium oxysporum f. sp. cubense followed by zinc sulphate (47.3, 42.7,...

  13. Induction of Systematic Resistance in Soybean Plants against Fusarium Wilt Disease by Seed Treatment with Benzothiadiazole and Humic Acid

    OpenAIRE

    Montaser Fawzy ABDEL-MONAIM; Mamdoh Ewis ISMAIL; Morsy, Kadry Mohamed

    2011-01-01

    The ability of benzothiadiazole (BTH), humic acid (HA) and their combination when used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Both inducers and their combination were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations i. e Minia and New Valley ...

  14. Comparison of Crop Rotation for Verticillium Wilt Management and Effect on Pythium Species in Conventional and Organic Strawberry Production

    OpenAIRE

    Krishna V Subbarao

    2009-01-01

    The effects of broccoli and lettuce rotations on population densities of Verticillium dahliae and Pythium spp. in soil and on strawberry (Fragaria × ananassa) growth, yield, and Verticillium wilt were evaluated in conventional and organic production systems in California for 2 years. Under both management systems, strawberry was planted after two successive crops of broccoli or lettuce. The control treatment in the conventional field was strawberry planted in soils fumigated with methyl bromi...

  15. Fluctuation of Fusarium distribution in soil and the role of the forecrop in the control of Fusarium wilt of flax

    OpenAIRE

    H. Zarzycka

    2015-01-01

    The influence of crop rotation and wheather conditions on the Fusarium population in soil and on Fusarium wilt of flax was examined in the Institute of Native Natural Fibres in 1968-1975. The experiments were carried out in various regions of flax planting in Poland during 8 years. Crop rotation had a significant influence on the process of biological soil disinfestation. Fusarium population in soil increased after planting flax, wheat, barley and sugar-beet, and decreased or did not change a...

  16. Detection of Fusarium wilt pathogens of Psidium guajava L. in soil using culture independent PCR (ciPCR)

    OpenAIRE

    Mishra, Rupesh K.; Pandey, Brajesh K.; Muthukumar, M.; Pathak, Neelam; Zeeshan, Mohammad

    2012-01-01

    Traditional culturing methods take a long time for identification of pathogenic isolates. A protocol has been developed for the detection of Fusarium from soil samples in the early stage of infection. Seventeen soil samples from different locations were collected before the onset of rains to find out the presence of Fusarium spp. population present in the soil of guava orchards and to correlate its presence with incidence of wilt. A PCR based method was developed for the molecular characteriz...

  17. 佛肚竹枯萎病的研究%A STUDY ON THE WILT DISEASE OF BAMBUSA VENTRICOSA

    Institute of Scientific and Technical Information of China (English)

    宋漳; 林毓银

    2001-01-01

    The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. Thesymptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bionomics of thewilt disease were studied. The species was identified as Nectria ditissirna Tul. at sexual phase, and as Fusarium semitec tum Berk. &Rav. at anamorphic state. The causal organism of wilt disease grew vigorously on the PSA and PSA + 10%decoction of culm media, and formed white coloured colonies. After incubation of 7 days at 28℃ , a great amount of macro-conidia was produced, no stroma and perithecia were formed after 30 days. The stroma and ascospore were only producedunder natural condition. The preference temperature for mycelia growth was between 25 ~ 28 ℃ , and the optimum pH val-ues was at 6 ~ 7. The optimum temperature for conidia and ascospores germination was between 25 ~ 28℃, and the opti-mum pH values was at 6 ~ 7. The high relative humidity ( RH 96.1% ~ 100% ) was necessary for the germination ofconidia and ascospores. The results of experiments showed that the pathogen of the wilt disease overwintered on the soil,and disseminated by winds and rains to infect the wounded stem base of Bambusa ventricosa. The primary infection occurredfrom the last ten days of February or the first days of March. The peak infection occurred from the first ten days of Marchto the second ten days of April during early summer rains. The infection ceased from the second ten days or the last tendays of May. The freeze injury was possibly important factor to induce infection of the wilt disease.

  18. Constitutive expression of a novel antimicrobial protein, Hcm1, confers resistance to both Verticillium and Fusarium wilts in cotton.

    Science.gov (United States)

    Zhang, Zhiyuan; Zhao, Jun; Ding, Lingyun; Zou, Lifang; Li, Yurong; Chen, Gongyou; Zhang, Tianzhen

    2016-01-01

    Fusarium and Verticillium wilts, two of the most important diseases in cotton, pose serious threats to cotton production. Here we introduced a novel antimicrobial protein Hcm1, which comprised harpin protein from Xanthomonas oryzae pv. oryzicola (Xoc), and the chimeric protein, cecropin A-melittin, into cotton. The transgenic cotton lines with stable Hcm1 expression showed a higher resistance to Verticillium and Fusarium wilts both in greenhouse and field trials compared to controls. Hcm1 enabled the transgenic cotton to produced a microscopic hypersensitive response (micro-HR), reactive oxygen species (ROS) burst, and caused the activation of pathogenesis-related (PR) genes in response to biotic stress, indicating that the transgenic cotton was in a primed state and ready to protect the host from pathogenic infection. Simultaneously, Hcm1 protein inhibited the growth of Verticillium dahliae (V. dahliae) and Fusarium oxysporum (F. oxysporum) in vitro. The spread of fungal biomass was also inhibited in vivo since the V. dahliae biomass was decreased dramatically in transgenic cotton plants after inoculation with V. dahliae. Together, these results demonstrate that Hcm1 could activate innate immunity and inhibit the growth of V. dahliae and F. oxysporum to protect cotton against Verticillium and Fusarium wilts. PMID:26856318

  19. Two rhizobacterial strains, individually and in interactions with Rhizobium sp., enhance fusarial wilt control, growth, and yield in pigeon pea.

    Science.gov (United States)

    Dutta, Swarnalee; Morang, Pranjal; Kumar S, Nishanth; Dileep Kumar, B S

    2014-09-01

    A Pseudomonas aeruginosa strain, RRLJ 04, and a Bacillus cereus strain, BS 03, were tested both individually and in combination with a Rhizobium strain, RH 2, for their ability to enhance plant growth and nodulation in pigeon pea (Cajanus cajan L.) under gnotobiotic, greenhouse and field conditions. Both of the rhizobacterial strains exhibited a positive effect on growth in terms of shoot height, root length, fresh and dry weight, nodulation and yield over the non-treated control. Co-inoculation of seeds with these strains and Rhizobium RH 2 also reduced the number of wilted plants, when grown in soil infested with Fusarium udum. Gnotobiotic studies confirmed that the suppression of wilt disease was due to the presence of the respective PGPR strains. Seed bacterization with drug-marked mutants of RRLJ 04 and BS 03 confirmed their ability to colonize and multiply along the roots. The results suggest that co-inoculation of these strains with Rhizobium strain RH 2 can be further exploited for enhanced growth, nodulation and yield in addition to control of fusarial wilt in pigeon pea. PMID:25224506

  20. Physiological mechanisms involved in resistance to cotton verticillium wilt induced by AM fungi

    Institute of Scientific and Technical Information of China (English)

    LIU Bing-jiang; LIU Run-jin

    2004-01-01

    @@ It was proved that arbuscular mycorrhizal (AM) fungi played an important role in increasing plant resistance to soilborne pathogens, especially when plants were pre-inoculated with AM fungi.Mechanisms involved in this phenomenon are not yet well understood. On the basis of the former experiment results in our lab, effects of AM fungi on cotton Verticillium wilt and the mechanisms of increasing disease resisitance by the tested fungi were studied in pot culture under greenhouse conditions. Two cotton cutivars Litai 8 and 86-1 which are susceptible to Verticillium dahliae were pre-inoculated with Glomus fasiculatum, and Gigaspora margarita, then inoculated with the strain of Verticillium dahliae, namely "An-Yang" (belong to intermediate virulent type) 30 days after the former inoculation. Results showed that AM fungi could improve the growth and development of cotton plants, increase plants dry mass, decrease incidence and disease index of Verticillium wilt of cotton plants, inhibit the infection and development of V. dahliae to different extent in the rhizosphere of cotton pre-inoculated with AM fungi, while the colonization and spore numbers of AM fungi were not reduced significantly by this pathogen. The defence enzymes, such as phenylalanine ammonia-lyase (PAL), chitinase, β-1, 3-glucanase, peroxidase, polyphenoloxidase (PPO) were induced, and their activities and peak increased by AM fungi in roots and leaves, and the increasing speed and peak of the enzyme activity were higher in treatment with AM fungus preinoculation than the inoculation with only V. dahliae, which suggested that defense response was activated by AM fungi, and then made the cotton to react strongly and rapidly to the infection of V. dahliae. In addition, AM fungi decreased the content of malondiadehyde (MDA) in cotton roots and leaves,protected membrane system and alleviated the damage caused by the pathogen. The AM fungus,Glomus fasiculatum showed the superior effects of biological

  1. Pattern of Flushing, Cherelle Wilt, and Accuracy of Yield Forecasting of Some Cocoa Clones

    Directory of Open Access Journals (Sweden)

    Adi Prawoto

    2014-08-01

    Full Text Available Monthly observation of cocoa flushing, number of cherelle wilt (CW, number of small, medium and large pods of 6 clones was conducted for two years to study its dynamics for one year. A study was conducted in Kaliwining Experimental Station, 45 m asl. and D rainfall type (according to Schmidt & Ferguson, using ICS 13, ICS 60, TSH 858, Sulawesi 1, Sulawesi 2 and KW 165 clones of 8 years old. Each clone was planted intermittently in separate rows, replicated 6 rows. Correlation and regression analysis were done between variables and with rainfall data. The parallel research was conducted in the similar station to assess the accuracy of production estimation method by identify percentage of small pods (length 1—10 cm, medium (11—15 cm and large pods (>15 cm to grow until harvested. The study used 15th years old trees of Sulawesi 1, Sulawesi 2, KW 165, KKM 22, ICS 13 and DR 2 clones. Each clones was replicated 5 times. The result showed that intensive flushing (>50% occured during January, March, September and November meanwhile no flushing during December and February. Correlation between rainfall and flushing was positive (r=0.27. Effect of clones on flushing frequency was similar but for flushing intensity was significant. KW 165 tended to be the lowest but TSH 858 tend to be the highest. CW occured for a year-round but the height level during May and June. Effect of clones was significant, KW 165 showed highest followed by Sulawesi 2. CW level showed positive correlation with number of medium (r=0.71 and big pods (r=0.55, except showed negative correlation with flushing intensity (r=-0.37 and rainfall (r=-0.51. High pod setting happened during May to November and low pod setting during December to March. In this aspect effect of clones were significant, the productive clones were Sulawesi 1, Sulawesi 2 and KW 165, but ICS 60 was the less. CW level during 1st semester was lower than at 2nd semester and clone effect was significant. The

  2. Efficacy of resistance selection to Verticillium wilt in strawberry (Fragaria x ananassa Duch. tissue culture

    Directory of Open Access Journals (Sweden)

    Jadwiga I. Żebrowska

    2012-12-01

    Full Text Available The soil-borne pathogenic fungus Verticillium dahliae Kleb. causes economic losses in crops in temperate regions of the world and hence is the most studied species. Strawberry (Fragaria x ananassa Duch. belongs to plant species susceptible to Verticillium dahliae, although the response to infection caused by this pathogen is varied and depends on the cultivar. Due to a lack of efficient methods in Verticillium wilt elimination, the selection of genetically resistant plant material is a priority direction in breeding programs. Efficacy of resistance selection to Verticillium dahliae Kleb. in strawberry tissue culture was examined on the basis of response to in vitro infection by this pathogenic fungus in two tissue cultured strawberry cultivars, i.e. 'Filon' and 'Teresa'. Culture was conducted for 16 months in an environmentally controlled growth room at 18-20°C, 60-70% relative humidity and light intensity of 100 µm E × m-2 × s-1 on a 16h light / 8h dark cycle. Subcultures were proliferated every 6 weeks on modified Murashige and Skoog medium. Four hundred microplants from each tissue cultured cultivar were inoculated under in vitro conditions at the 4-leaf stage with a homogenate of liquid mycelium of Verticillium dahliae serving as the selecting agent. Disease symptoms were observed at 15, 30, 45, 60, and 75th days post inoculation. The extent of leaf chlorosis was rated on a scale of 0-4. At day 75th post inoculation, the percentage of totally chlorotic plants in micropropagated cv. Teresa reached the value of 76.27%, whereas the proportion of such plants in inoculated tissue cultured cv. Filon reached the value of 89.40%. Also, the index of infection calculated for very severe disease symptoms in the subclone 'Teresa' reached the mean value lower when compared with that calculated for subclone 'Filon' (0.0962 and 0.1150, respectively. These results suggested that the micropropagated cv. Teresa exhibited higher genetic resistance to the

  3. Physiological and biochemical aspects of the resistance of banana plants to Fusarium wilt potentiated by silicon.

    Science.gov (United States)

    Fortunato, Alessandro Antonio; Rodrigues, Fabrício Ávila; do Nascimento, Kelly Juliane Teles

    2012-10-01

    Silicon amendments to soil have resulted in a decrease of diseases caused by several soilborne pathogens affecting a wide number of crops. This study evaluated the physiological and biochemical mechanisms that may have increased resistance of banana to Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense, after treatment with silicon (Si) amendment. Plants from the Grand Nain (resistant to F. oxysporum f. sp. cubense) and "Maçã" (susceptible to F. oxysporum f. sp. cubense) were grown in plastic pots amended with Si at 0 or 0.39 g/kg of soil (-Si or +Si, respectively) and inoculated with race 1 of F. oxysporum f. sp. cubense. Relative lesion length (RLL) and asymptomatic fungal colonization in tissue (AFCT) were evaluated at 40 days after inoculation. Root samples were collected at different times after inoculation with F. oxysporum f. sp. cubense to determine the level of lipid peroxidation, expressed as equivalents of malondialdehyde (MDA), hydrogen peroxide (H(2)O(2)), pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids), total soluble phenolics (TSP), and lignin-thioglycolic acid (LTGA) derivatives; the activities of the enzymes phenylalanine ammonia-lyases glucanases (PALs), peroxidases (POXs), polyphenoloxidases (PPOs), β-1,3-glucanases (GLUs), and chitinases (CHIs); and Si concentration in roots. Root Si concentration was significantly increased by 35.3% for the +Si treatment compared with the -Si treatment. For Grand Nain, the root Si concentration was significantly increased by 12.8% compared with "Maçã." Plants from Grand Nain and "Maçã" in the +Si treatment showed significant reductions of 40.0 and 57.2%, respectively, for RLL compared with the -Si treatment. For the AFCT, there was a significant reduction of 18.5% in the +Si treatment compared with the -Si treatment. The concentration of MDA significantly decreased for plants from Grand Nain and "Maçã" supplied with Si compared with the -Si treatment while the

  4. IMPROVMENT BIOCONTROL OF DAMPING-OFF AND ROOT ROT/WILT OF FABA BEAN BY SALICYLIC ACID AND HYDROGEN PEROXIDE

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    Montaser F. Abdel-Monaim

    2013-04-01

    Full Text Available Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40 causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride, Bacillus megaterium and chemical inducers (salicylic acid and hydrogen peroxide individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promotion of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi.Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA+ B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/ wilt severity and increased survival of plants. Also, these treatments increased fresh and dry weights of the survived plants in pots compared with control.  The combination of biocontrol agents and chemical inducers were more effective than using them individually and SA+ T. viride was the best treatment in this respect. Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1 and yield components (No. of pods and seedsplant-1, weight of 100 seeds and total yield feddan-1 and protein content in both seasons (2010-2011 and 2011-2012. Faba bean seeds soaked in SA+ T. viride and SA+ B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination of biocontrol agents and

  5. Water relations in the interaction of foliar bacterial pathogens with plants.

    Science.gov (United States)

    Beattie, Gwyn A

    2011-01-01

    This review examines the many ways in which water influences the relations between foliar bacterial pathogens and plants. As a limited resource in aerial plant tissues, water is subject to manipulation by both plants and pathogens. A model is emerging that suggests that plants actively promote localized desiccation at the infection site and thus restrict pathogen growth as one component of defense. Similarly, many foliar pathogens manipulate water relations as one component of pathogenesis. Nonvascular pathogens do this using effectors and other molecules to alter hormonal responses and enhance intercellular watersoaking, whereas vascular pathogens use many mechanisms to cause wilt. Because of water limitations on phyllosphere surfaces, bacterial colonists, including pathogens, benefit from the protective effects of cellular aggregation, synthesis of hygroscopic polymers, and uptake and production of osmoprotective compounds. Moreover, these bacteria employ tactics for scavenging and distributing water to overcome water-driven barriers to nutrient acquisition, movement, and signal exchange on plant surfaces. PMID:21438680

  6. [Molecular identification and sequence analysis of broad bean wilt virus 2 isolates from atractylodes macrocephala Koidz].

    Science.gov (United States)

    Niu, Yanbing; Shi, Xiaoli; Zhang, Ximei; Zhao, Huiqi; Zhao, Baojia

    2015-01-01

    To identity the pathogen that causes the mosaic and yellowing symptoms on Atractylodes macrocephala Koidz in Jiangxian, Shanxi province, biological inoculation, sequence-independent amplification (SIA),RT-PCR and other identification methods were used. The results showed that the chlorotic and necrosis symptoms occurred in the indicator plant Chenopodium quinoa after it was infected with the pathogen,and the same symptoms appeared after the reinoculation of healthy Atractylodes macrocephala Koidz; this reflected that the disease was likely to be caused by a virus. The results of SIA and sequencing showed that Broad bean wilt virus 2 (BBWV2) was present in severely mosaic Atractylodes macrocephala Koidz leaves. To further characterize the BBWV2 isolate from Atractylodes macrocephala (BBWV2-Am), the polyprotein partial gene encoded by BBWV2-Am RNA2 was cloned and sequenced. Sequence alignments showed that the nucleotide sequence identity of BBWV2-Am SCP and LCP genes ranged from 79.3% to 87.2% and from 80.1% to 89.2% compared to other BBWV2 strains,respectively; the deduced amino acid sequence similarities of the two gene products ranged from 91.2% to 95.7% and from 89.44 to 95.5%, respectively,compared to those of other BBWV2 strains. Phylogenetic comparisons showed that BBWV2-Am was most likely to be related to BBWV2-Rg,but formed an independent branch. This is the first report of BBWV2 in Atractylodes macrocephala Koidz. PMID:25997332

  7. Genetics of Fusarium Wilt Resistance in Pigeonpea (Cajanus cajan) and Efficacy of Associated SSR Markers

    Science.gov (United States)

    Singh, Deepu; Sinha, B.; Rai, V. P.; Singh, M. N.; Singh, D. K.; Kumar, R.; Singh, A. K.

    2016-01-01

    Inheritance of resistance to Fusarium wilt (FW) disease caused by Fusarium udum was investigated in pigeonpea using four different long duration FW resistant genotypes viz., BDN-2004-1, BDN-2001-9, BWR-133 and IPA-234. Based on the F2 segregation pattern, FW resistance has been reported to be governed by one dominant gene in BDN-2004-1 and BDN-2001-9, two duplicate dominant genes in BWR-133 and two dominant complimentary genes in resistance source IPA-234. Further, the efficacy of six simple sequence repeat (SSR) markers namely, ASSR-1, ASSR-23, ASSR-148, ASSR-229, ASSR-363 and ASSR-366 reported to be associated with FW resistance were also tested and concluded that markers ASSR-1, ASSR-23, ASSR-148 will be used for screening of parental genotypes in pigeonpea FW resistance breeding programs. The information on genetics of FW resistance generated from this study would be used, to introgress FW resistance into susceptible but highly adopted cultivars through marker-assisted backcross breeding and in conventional breeding programs. PMID:27147929

  8. Genetic Compositions of Broad bean wilt virus 2 Infecting Red Pepper in Korea

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    Hae-Ryun Kwak

    2013-09-01

    Full Text Available The incidence of Broad bean wilt virus 2 (BBWV2 on red pepper was investigated using the samples obtained from 24 areas of 8 provinces in Korea. Two hundred and five samples (79% out of 260 collected samples were found to be infected with BBWV2. While the single infection rate of BBWV2 was 21.5%, the co-infection rate of BBWV2 with Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus and/or Potato virus Y was 78.5%. To characterize the genetic diversity of BBWV2 Korean isolates, 7 isolates were fully sequenced and analyzed. Phylogenetic analyses revealed that BBWV2 isolates could be divided largely into two groups as Group I and Group II. Based on the partial sequence analyses, 153 selected BBWV2 isolates were subgrouped into GS-I (21.6%, GS-II (3.9% and GS-III (56.9%. BBWV2 GS-III, which was predominant in Korea, appears to be a new combination between Group I RNA-1 and Group II RNA-2. Viral disease incidence of BBWV2 on red pepper was under 2% before 2004. However, the incidence was increased abruptly to 41.3% in 2005, 58.2% in 2006 and 79% in 2007. These rapid increases might be related with the emergence of new combinations between BBWV2 groups.

  9. Status of tobacco viruses in Serbia and molecular characterization of tomato spotted wilt virus isolates.

    Science.gov (United States)

    Stanković, I; Bulajić, A; Vučurović, A; Ristić, D; Milojević, K; Berenji, J; Krstić, B

    2011-01-01

    In a four-year survey to determine the presence and distribution of viruses in tobacco crops at 17 localities of the Vojvodina Province and Central Serbia, 380 samples were collected and analyzed by DAS-ELISA. Out of the seven viruses tested, tomato spotted wilt virus (TSWV), potato virus Y (PVY), tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), and alfalfa mosaic virus (AMV) were detected in 37.9, 33.4, 28.7, 23.9, and 15.5% of the total tested samples, respectively. TSWV was the most frequently found virus at the localities of Central Serbia, while PVY and CMV were the most frequent viruses in the Vojvodina Province. Single infections were prevalent in years 2005-2007 and the most frequent were those of PVY. A triple combination of those viruses was most frequent mixed infection type in 2008. The presence of all five detected viruses was confirmed in selected ELISA-positive samples by RT-PCR and sequencing. The comparisons of obtained virus isolate sequences with those available in NCBI, confirmed the authenticity of serologically detected viruses. Phylogenetic analysis based on partial nucleocapsid gene sequences revealed a joint clustering of Serbian, Bulgarian and Montenegrin TSWV isolates into one geographic subpopulation, which was distinct from the other subpopulation of TSWV isolates from the rest of the European countries. The high incidence of viruses in Serbian tobacco crops highlights the importance of enhancing farmers knowledge towards better implementation of control strategies for preventing serious losses. PMID:22149499

  10. Expression analysis of fusarium wilt resistance gene in melon by real-time quantitative pcr

    International Nuclear Information System (INIS)

    Melon Actin gene was used as a reference gene, to explore the gene expression profiles of the Fom-2 gene in roots, stems, and leaves of melon MR-1 under induction by Fusarium oxysporum f. sp. melonis. Monitoring using real-time quantitative PCR showed similar accumulation patterns of Fom-2 in roots, stems, and leaves over the observation period of 1 to 11 days; the expression level in stems was the highest. The expression of the Fom-2 gene was strengthened by the prolongation of induction time. In stems, the expression of Fom-2 was 5.737 times higher than in the control at three days; in roots, expression of Fom-2 was 5.617 times higher than in the control at five days. Similarly, the expression of Fom-2 in leaves obviously increased. It was 4.441 times higher than in the control at 5 days. The expression of Fom-2 was non-tissue specific, up-regulated under induction by Fusarium, and related to early resistance to Fusarium wilt. (author)

  11. Search for alternate hosts of the coconut Cape Saint Paul Wilt Disease pathogen

    Directory of Open Access Journals (Sweden)

    Yankey Egya Ndede

    2009-03-01

    Full Text Available Lethal Yellowing disease locally called Cape Saint Paul wilt disease (CSPWD is the bane of the coconut industry in Ghana and is caused by a phytoplasma. In Ghana, there are areas where the disease has re-infected re-plantings long after decimating all the palms in the area. This brings to the fore the possibility of alternate hosts in the spread of the disease because the pathogen is an obligate parasite. In this work, a number of plants were screened for their host status to the CSPWD pathogen. The presence of phytoplasmas in these plants was tested by polymerase chain reaction analysis using universal phytoplasma primers P1/P7 and CSPWD-specific primers G813/GAKSR. Although Desmodium adscendens tested positive to the CSPWD-specific primers, cloning and sequencing did not confirm it as an alternate host. The identification of alternate hosts will help us to evolve sound control strategies against the spread of the disease.

  12. Infection Trace of Pine Wilt Disease Based on Terahertz Spectroscopic Technology

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    Ling Jiang

    2014-05-01

    Full Text Available In this study, we present the terahertz spectroscopic features of pine needle infected by pine wilt disease during different infection stages by applying terahertz spectroscopic techniques. We measure the absorption variation of the pine needle samples with infection time by Terahertz Time Domain Spectroscopy (THz-TDS. The absorption intensity in the frequency region of 0-2.5 THz increases gradually with infection time. While the pine wood is infected above four months, the absorption intensity reaches to maximum. However, the calculated relative refractive index compared with the reference signal of PET powder reduces with infection time. The higher frequency measurement by Fourier Transform Infrared spectroscopy (FTIR doesn’t show the absorption variation of the samples due to huge signal attenuation in the transmission path of the samples. This study demonstrates that the relation of absorption intensity and refractive index of the pine needle sample with the infection time. We can trace the infection extent of the pine wood by measuring its terahertz spectroscopic property

  13. Molecular Marker-assisted Selection for Verticillium Wilt Resistance in Upland Cotton (Gossypium hirsutum)%陆地棉抗黄萎病性状分子标记辅助选择

    Institute of Scientific and Technical Information of China (English)

    Shui-jin ZHU; Wei-ping FANG; Dao-fan JI

    2002-01-01

    @@ Verticillium wilt is a global important disease of cotton, which threatens the development of cotton production seriously. Recent years,because of the change in climate and cropping pattern, Verticillium wilt was broke out in cotton production areas in China, which became one of the most important factors restricting the continuant development of cotton production.

  14. Qualidade e valor nutritivo de silagens de capim-marandu (B. brizantha cv. Marandu produzidas com aditivos ou forragem emurchecida Quality and nutritive value of marandugrass (Brachiaria brizanthia, cv. Marandu silage prepared with additive or wilting

    Directory of Open Access Journals (Sweden)

    Antonio Fernando Bergamaschine

    2006-08-01

    Full Text Available Avaliaram-se a qualidade e o valor nutritivo de silagens de capim-marandu produzidas com polpa cítrica (PC peletizada, com aditivo enzimático-bacteriano (ABE ou com forragem emuchercida (E: T1 - forragem sem tratamento (controle; T2 - 10% de polpa cítrica peletizada (PC; T3 - aditivo enzimático bacteriano (AEB - SIL-ALL-C4 da Alltech, à base de 5 g/L de água/t de forragem; T4 - forragem picada grosseiramente emurchecida por 4 horas ao sol. O capim foi colhido aos 60 dias de rebrota (24% MS. Para avaliar o consumo e a digestibilidade das silagens, foram utilizados 16 novilhos mestiços com 200 kg de PV, que receberam, além das silagens, 1,0 kg de concentrado/animal/dia. O AEB não afetou a composição da silagem, mas a PC e o E aumentaram o teor de MS de 24% para 31 e 48%, respectivamente, e reduziram o pH e os teores de N-NH3 das silagens, que foram, respectivamente, de 4,17 e 4,58 e 6,78 e 7,99% NT. A PC diminuiu os teores de FDN e FDA em 12 e 4 unidades percentuais. O consumo de MS da silagem produzida com capim emurchecido foi superior (111,8 g MS/PV0,75 ao das silagens controle ou com AEB, mas não diferiu do obtido para a silagem com PC, que também não diferiu das demais. Os tratamentos não afetaram a digestibilidade, cujas médias para MS, PB, CT, FDN, FDA e NDT foram 67,0; 65,4; 68,8; 63,0; 62,5; e 65,6%, respectivamente. A PC e o E reduziram a proteólise e estimularam o consumo. A PC, o E e o AEB não melhoraram o valor nutritivo da silagem de capim-marandu colhido com 24% MS.The objective of this experiment was to evaluate the quality and nutritive value of marandugrass silages. It was evaluated the followings treatments: T1- forage without treatment (control; T2 - 10% of pelleted citric pulp (CiP; T3 - enzymatic bacterial additive (EBA (SIL-ALL-C4 of Alltech applied at 5 g/L of water/t of forage; T4 - Coarse chopped forage wilted for 4 hours under the sun. The grass was harvested with 60 days of regrowth (24% DM. The intake

  15. 西瓜枯萎病土壤拮抗菌的筛选%Screening of Soil Antagonistic Bacteria for Watermelon Fusarium Wilt

    Institute of Scientific and Technical Information of China (English)

    胡雪芹; 张洪斌; 苏晓飞

    2008-01-01

    [Objective] The aim of this study was to screen bacteria strains with stable antagonistic effect against watermelon fusarium wilt from soil and investigate the biological control of watermelon fusarium wilt by applying the antagonistic bacteria strains into soil. [Method] Actinomycete strains, fluorescent bacteria strains and bacillus strains were isolated from soil samples by the dilution-plate method, then its resistance was screened respectively by the improved confront culture method after colonies were purified. Finally, bacteria strains with better antagonistic effect were identified. [Result] 29 bacteria strains with stable antagonistic effect against watermelon fusarium wilt were screened from 39 soil samples, which contained 15 fluorescent bacteria strains, 5 bacillus strains and 9 actinomycete strains. Furthermore, three antagonistic bacteria strains of FM2, FM3 and FM4 with the strongest antagonism were identified primarily. [Conclusion] According to cultural characteristics, morphological observation, biochemical and physiological tests, FM2 belongs to bacillus subtilis, while FM3 and FM4 belong to micrococcus.

  16. Bacterial Nail Infection (Paronychia)

    Science.gov (United States)

    ... of nail infection is often caused by a bacterial infection but may also be caused by herpes, a ... to a type of yeast called Candida , or bacterial infection, and this may lead to abnormal nail growth. ...

  17. Quantitative Trait Loci in Sweet Corn Associated with Partial Resistance to Stewart's Wilt, Northern Corn Leaf Blight, and Common Rust.

    Science.gov (United States)

    Brown, A F; Juvik, J A; Pataky, J K

    2001-03-01

    ABSTRACT Partial resistance to Stewart's wilt (Erwina stewartii, syn. Pantoea stewartii), northern corn leaf blight (NCLB) (Exserohilum turcicum), and common rust (Puccinia sorghi) was observed in an F(2:3) population developed from a cross between the inbred sweet corn lines IL731a and W6786. The objective of this study was to identify quantitative trait loci (QTL) associated with partial resistance using restriction fragment length polymorphic markers. Phenotypic data were collected for 2 years for Stewart's wilt, NCLB, and common rust but, due to significant family-environment interaction, analysis was conducted individually on data from each year. In 2 years of evaluation for the three diseases, a total of 33 regions in the maize genome were associated with partial resistance describing from 5.9 to 18% of the total phenotypic variability. Of six regions common in both years, three were associated with partial resistance to Stewart's wilt (chromosomes 4:07, 5:03, and 6:04), one was associated with NCLB (chromosome 9:05), and two were associated with common rust (chromosomes 2:04 and 3:04). The rust QTL on 3S mapped to within 20 cM of the rp3 locus and explained 17.7% of the phenotypic variability. Some of the QTL associated with partial resistance to the three diseases have been reported previously, and some are described here for the first time. Results suggest it may be possible to consolidate QTL from various elite backgrounds in a manner analogous to the pyramiding of major resistance genes. We also report here on two QTL associated with anthocyanin production on chromosomes 10:6 and 5:03 in the general location of the a2 gene. PMID:18943349

  18. A study of interaction between Verticillium wilt Verticillium dahliae and root-knot nematode Meloidogyne javanica in olive cultivars.

    Science.gov (United States)

    Saeedizadeh, Ayatollah; Kheiri, Ahmad; Zad, Javad; Etebarian, Hasan Reza; Bandani, Ali Reza; Nasiri, Mohammad Bagher

    2009-01-01

    Second stage juvenile (J2) of root-knot nematode, Meloidogyne javanica, and microsclerotia of verticillium wilt, Verticillium dahliae, were used as the source of inoculum for nematode and fungus respectively. One-year-old seedlings of olive cultivars, Zard, Roghani, Koroneiki and Manzanilla, were transplanted to pots containing 2000g of sterilized sandy loam soil. Experiment was conducted in completely randomized design with 32 treatments and five replications. Treatments were as follows: control, nematode alone, fungus alone and fungus + nematode. Pots were inoculated with (0, 2000, 3000, 4000) J2 of nematode and/or (10 no/g soil) microsclerotia of fungus according to the treatments. Experiment was terminated after 10 months and fallowing parameters were determined i.e., fresh weight of root and stem, number of galls and egg masses per root system, and percentage of incidence of symptom on aerial parts, browning of vascular tissue, decrease of seedling height and stem/root tissue colonization by fungus. Results showed that presence of nematode caused reduction on colonization of the fungus in the root and stem and vice versa i.e. presence of fungus caused reduction on number of galls and egg masses produced by the nematode. Severe fungus wilt on aerial parts of Manzanilla cultivar was observed when both pathogens were inoculated and mild fungus wilt was observed in fungus alone treatments of Koroneiki cultivar. Galling and egg mass production in root system were reduced in cvs Manzanilla, Zard, Roghani and Koroneiki, respectively (p Manzanilla, respectively (p < or = 0/05). PMID:20222619

  19. Arbuscular mycorrhizal fungi (AMF) as bio protector agents against wilt induced by Verticillium spp. in pepper

    Energy Technology Data Exchange (ETDEWEB)

    Goicoechea, N.; Garmendia, I.; Sanchez-Diaz, M.; Aguirreolea, J.

    2010-07-01

    Verticillium dahliae Kleb. is a vascular pathogen that alters water status and growth of pepper plants and causes drastic reductions in yield. Its control is difficult because it can survive in field soil for several years. The application of arbuscular mycorrhizal fungi (AMF) as bio protector agents against V. dahliae is an alternative to the use of chemicals which, in addition, is more respectful with the environment. The establishment of the mutualistic association of plant roots and AMF involves a continuous cellular and molecular dialogue between both symbionts that includes the pre activation of plant defense responses that may enhance the resistance or tolerance of mycorrhizal plants to soil-borne pathogens. Some AMF can improve the resistance of Capsicum annuum L. against V. dahliae. This is especially relevant for pepper cultivars (i.e. cv. Piquillo) that exhibit high susceptibility to this pathogen. Compared with non-mycorrhizal plants, mycorrhizal pepper can exhibit more balanced antioxidant metabolism in leaves along the first month after pathogen inoculation, which may contribute to delay both the development of disease symptoms and the decrease of photosynthesis in Verticillium-inoculated plants with the subsequent benefit for yield. In stems, mycorrhizal pepper show earlier and higher deposition of lignin in xylem vessels than non mycorrhizal plants, even in absence of the pathogen. Moreover, AMF can induce new isoforms of acidic chitinases and superoxide dismutase in roots. Mycorrhizal-specific induction of these enzymatic activities together with enhanced peroxidase and phenylalanine ammonia-lyase in roots may also be involved in the bio protection of Verticillium-induced wilt in pepper by AMF. (Author) 81 refs.

  20. Use of additives and pre-wilting in Tifton 85 bermudagrass silage production

    Directory of Open Access Journals (Sweden)

    Marcela Abbado Neres

    2014-02-01

    Full Text Available The use of tropical grasses silage has become common in ruminant feed. An experiment was conducted to evaluate the fermentation characteristics, nutritional value, pH, fermentative capacity, ammonia nitrogen / total nitrogen (NH3N/total N of Tifton 85 bermudagrass grass silage with different additives and wilting. The treatments were: pre-drying in the sun for two hours before silage, use of inoculant-enzymatic addition of soybean hulls, corn grits addition and use of salt in the surface layer of the silo. The experimental design was completely randomized with 6 treatments and 4 replications. Plants of Tifton 85 bermudagrass with 38 days of growth were ensiled in experimental silos with Bunsen valve type with packing densities of 236 kg of silage per m³ for Tifton 85 bermudagrass pre-dried in the sun and 294 kg of silage per m³ for the other treatments. The proportions of soybean hulls and corn grits added to the silage were calculated based on the initial DM content of Tifton 85 bermudagrass order to obtain MS 320 g kg-1 for the material to be ensiled. The buffering capacity did not differ between treatments in getting 29.56 (meqHCl/100gMS. It was found that the concentration of ammonia nitrogen did not differ between silages and remained low (3.22 g kg-1, the pH after silo opening was also similar with an average of 4.09 getting above 4.2 only in Tifton 85 bermudagrass silage without pre-treatment. The crude protein was higher in silages Tifton 85 bermudagrass and Tifton 85 bermudagrass with soybean hulls (17.48 g kg-1. The use corn grits caused a reduction in the values of NDF. The use of salt on the surface the layer reduced the production of latic and acetic acid.

  1. Native cell-death genes as candidates for developing wilt resistance in transgenic banana plants.

    Science.gov (United States)

    Ghag, Siddhesh B; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2014-01-01

    In order to feed an ever-increasing world population, there is an urgent need to improve the production of staple food and fruit crops. The productivity of important food and fruit crops is constrained by numerous biotic and abiotic factors. The cultivation of banana, which is an important fruit crop, is severely threatened by Fusarium wilt disease caused by infestation by an ascomycetes fungus Fusarium oxysporum f. sp. cubense (Foc). Since there are no established edible cultivars of banana resistant to all the pathogenic races of Foc, genetic engineering is the only option for the generation of resistant cultivars. Since Foc is a hemibiotrophic fungus, investigations into the roles played by different cell-death-related genes in the progression of Foc infection on host banana plants are important. Towards this goal, three such genes namely MusaDAD1, MusaBAG1 and MusaBI1 were identified in banana. The study of their expression pattern in banana cells in response to Foc inoculation (using Foc cultures or fungal toxins like fusaric acid and beauvericin) indicated that they were indeed differentially regulated by fungal inoculation. Among the three genes studied, MusaBAG1 showed the highest up-regulation upon Foc inoculation. Further, in order to characterize these genes in the context of Foc infection in banana, we generated transgenic banana plants constitutively overexpressing the three genes that were later subjected to Foc bioassays in a contained greenhouse. Among the three groups of transgenics tested, transformed banana plants overexpressing MusaBAG1 demonstrated the best resistance towards Foc infection. Further, these plants also showed the highest relative overexpression of the transgene (MusaBAG1) among the three groups of transformed plants generated. Our study showed for the first time that native genes like MusaBAG1 can be used to develop transgenic banana plants with efficient resistance towards pathogens like Foc. PMID:24996429

  2. ''In vitro'' mutation breeding methodology for Fusarium wilt resistance in banana

    International Nuclear Information System (INIS)

    Full text: Besides ''in vivo'' methods, the Radiation Genetics Section of CENA/USP is also using ''in vitro'' methods for mutation breeding to obtain resistance to Panama disease caused by Fusarium oxysporum f.sp. cubense in the banana cultivar ''Maca''. A protocol has been established for the ''in vitro'' development of shoot tips, obtained from plants in the field or already cultivated under in vitro'' conditions. For both cases, only one culture medium was used during all steps of ''in vitro'' cultivation. New buds were formed and these buds grew and developed to form roots. The medium was composed of macro and micro nutrients, with added Morel vitamines, BAP (5 mg/l), saccharose (30 g/l) and agar (6.5 g/l), at pH 5.7. Cultures were allowed to grow in a controlled environment at 27 deg. C and 16 h illumination. Shoot tips which originated from ''in vitro'' plantlets, were cut longitudinally down the middle. This was done to avoid a tendency of regeneration of the original tissue instead of the formation of new lateral buds. To resolve the chimerism resulting when mutagenic treatment is applied to shoot tips, there is a need of vegetative propagation of new lateral buds. Selection can then be done at M1V4 generation. Once the protocol was established, the gamma ray sensitivity was determined. The dose that produced a 50% decrease in the number of new lateral buds was around 40 Gy and this dose will be utilised. The methodology was completed by soil inoculation with Fusarium of young plants 15 cm in height, obtained from ''in vitro'' cultures. After 3 weeks all inoculated plants showed symptoms of wilt, demonstrating the possibility of screening. The method is now being utilised on a large scale in an attempt to induce a resistant mutant. (author)

  3. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  4. New Mexico and the southwestern US are affected by a unique population of tomato spotted wilt virus (TSWV) strains.

    Science.gov (United States)

    French, J M; Goldberg, N P; Randall, J J; Hanson, S F

    2016-04-01

    Tomato spotted wilt virus (TSWV) is an important pathogen of many ornamental, greenhouse and agronomic crops worldwide. TSWV also causes sporadic problems in a number of crops in New Mexico (NM). Nucleocapsid gene sequences obtained from six different crop species across the state over four different years were used to characterize the NM TSWV population. This analysis shows that NM is affected by a unique TSWV population that is part of larger independent population present in the southwestern US. This population likely arose due to geographic isolation and is related to other TSWV populations from the US, Spain, and Italy. PMID:26721573

  5. QTL Analysis of Fiber Yield and Quality and Resistance to Verticillium Wilt Using Gossypium hirsutum and G.barbadense Advanced Backcross Populations

    Institute of Scientific and Technical Information of China (English)

    LI Ai-guo; WANG Tao; YUAN You-lu; LIU Guang-ping; ZHANG Bao-cai; LI Jun-wen; SHI Yu-zhen; LIU Ai-ying; YANG Ze-mao; LIU Zhi; YU Xiao-nan

    2008-01-01

    @@ To introgress elite QTL alleles of Gossypium barbadense L.for fiber yield and quality and resistance to Verticillium wilt into G.hirsutum L.,enlarge the genetic base of G.hirsutum,and provide new germplasm resources for the variety development,the cultivars Zhongmiansuo 36,G.hirsutum,and Hai 1,G.barbadense,were used as recurrent and donor parent,respectively,to produce BC1 F1,BC1S1,and BC2F1 populations.QTL analyses of fiber quality,yield-related,Key words: interspecific backcrosss; AB-QTL; fiber quality; yield; Verticillium wilt resistance

  6. Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide

    OpenAIRE

    Montaser Fawzy ABDEL-MONAIM

    2013-01-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogen...

  7. Control of Wilt and Blight Diseases of Cumin through Antagonistic Fungi under in Vitro and Field Conditions

    Directory of Open Access Journals (Sweden)

    P. DEEPAK

    2008-08-01

    Full Text Available The experiment was carried out to assess their possible use as bio-agents for several antagonistic fungi on growth of two cumin fungal pathogens under in vitro and field conditions. Under in vitro conditions maximum inhibition (82.86% of radial growth of Fusarium oxysporum f. sp. cumini was observed with the treatment of Trichoderma harzianum strain I, whereas maximum inhibition (85.45% of the mycelial growth of Alternaria burnsii was observed in the presence of Trichoderma harzianum strain II. The antagonists who showed maximum inhibition of the pathogen in laboratory conditions were applied in field conditions as soil treatment/seed treatment or as foliar spray. The incidence of wilt disease was found to be lowest (PDI 27.40% when soil was treated with Trichoderma harzianium strain I at the rate of 24g / 6m2 (weight of fungus with sorghum seeds. Minimum blight disease incidence was observed when T. harzianum strain II was applied to the soil at the rate of 24g / 6m2 (36.15% or when 10% spore suspension of T. harzianum strain II was applied as seed treatment at the time of sowing and as spray at the time of flowering (PDI 35.10%. Thus treatments of Trichoderma harzianum strain I for wilt and Trichoderma harzianum strain II for blight diseases of cumin under both the conditions @ 24g / 6m2 or 40kg / ha seems promising for sustainable management of crop diseases.

  8. Improvements in seed yield, oil quality and tolerance to sesame wilt disease pathogens using induced mutation and hybridization

    International Nuclear Information System (INIS)

    The air dried seeds of two Egyptian local sesame cultivars were exposed to a wide range (100 to 800 Gy) of gamma ray doses from a 60Co source. The dose rate at the time of irradiation was 1 Gy/s. Irradiated and non-irradiated seeds were immediately sown in the experimental field and selection of plants with morphological changes was practised up to the M2 generation. Superior mutant lines that surpassed their mother type in one or more character(s) related to seed yield were tested in on-farm trials. To improve early maturity, seed shattering and seed yield, superior mutant lines were crossed with local and introduced germplasm. Selection for disease tolerance to wilt and root rot fungi causing sesame wilt was practised by artificial inoculation of the soil with a single fungus. A new method for inoculum preparation and soil infestation in pot and field experiments was adopted; all the selected lines raised from the mutation programme or from the crossing block had to pass this pathological test for three successive seasons and to be highly tolerant to sesame fungal diseases. 2 tabs

  9. Comparison of fungal community in black pepper-vanilla and vanilla monoculture systems associated with vanilla Fusarium wilt disease

    Directory of Open Access Journals (Sweden)

    Qirong eShen

    2016-02-01

    Full Text Available Long-term vanilla monocropping often results in the occurrence of vanilla Fusarium wilt disease, seriously affecting its production all over the world. In the present study, vanilla exhibited significantly less Fusarium wilt disease in the soil of a long-term continuously cropped black pepper orchard. The entire fungal communities of bulk and rhizosphere soils between the black pepper-vanilla system (i.e., vanilla cropped in the soil of a continuously cropped black pepper orchard and vanilla monoculture system were compared through the deep pyrosequencing. The results showed that the black pepper-vanilla system revealed a significantly higher fungal diversity than the vanilla monoculture system in both bulk and rhizosphere soils. The UniFrac-weighted PCoA analysis revealed significant differences in bulk soil fungal community structures between the two cropping systems, and fungal community structures were seriously affected by the vanilla root system. In summary, the black pepper-vanilla system harboured a lower abundance of F. oxysporum in the vanilla rhizosphere soil and increased the putatively plant-beneficial fungal groups such as Trichoderma and Penicillium genus, which could explain the healthy growth of vanilla in the soil of the long-term continuously cropped black pepper field. Thus, cropping vanilla in the soil of continuously cropped black pepper fields for maintaining the vanilla industry is executable and meaningful as an agro-ecological system.

  10. Induction of Systematic Resistance in Soybean Plants against Fusarium Wilt Disease by Seed Treatment with Benzothiadiazole and Humic Acid

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2011-05-01

    Full Text Available The ability of benzothiadiazole (BTH, humic acid (HA and their combination when used as seed soaking to induce systemic resistance against a pathogenic strain of Fusarium oxysporum was examined in four soybean cultivars under greenhouse conditions. Both inducers and their combination were able to protect soybean plants against damping-off and wilt diseases compared with check treatment. These results were confirmed under field conditions in two different locations i. e Minia and New Valley governorates. The tested treatments significantly reduced damping-off and wilt diseases and increased growth parameters, except number of branches plant-1, and seed yield. Application of BTH (0.25 + HA (4 g/l was the most potent in this respect treatment. Soybean seed soaking in BTH+ HA recorded the highest activities of the testes of oxidative enzymes followed by BTH in the four soybean cultivars. Whereas, HA treatment was recorded the lowest increased of these oxidative enzymes. Also, similar results were obtained in case of total phenol but HA increased the total phenol more than BTH in all tested cultivars.

  11. Effect of root exudates of different resistant varieties of cucumber on fusarium wilt and preliminary studies on their resistance mechanism

    Institute of Scientific and Technical Information of China (English)

    Benli HUANG; Yundong XU; Ye WU; Shunqi ZHANG; Xuchao CHEN

    2008-01-01

    This study investigated the effect of root exudates of cucumber varieties, Jinyan 4 (susceptible variety), Jinchun 4 (resistant variety) and Yinnan Black seed squash on fusa-rium wilt. The results showed that fusarium wilt occurrence of plants treated with the root exudate of Jinyan 4 was earlier. The infection rate was significantly higher 15 days after inoculation, but similar to the control 20 days after inocula-tion. In contrast, the infection rate of plants treated with the root exudate of Jinchun 4 was significantly lower than that of the control. The plant height and fresh weight of Jinyan 4 treated with its own root exudate were lower than those of the control, and the root vigor decreased but the conductance increased. There was no significant effect of the root exudates from Jinchun 4 and Black seed squash on plant height and fresh mass of Jinyan 4. We found that the root exudate of susceptible cucumber variety stimulated the growth of Fusarium oxysporum pathogen, in contrast, that of resistance variety and Black seed squash suppressed the growth.

  12. Induced resistance by cresotic acid (3-hydroxy-4-methyl methylbenzoic acid) against wilt disease of melon and cotton

    International Nuclear Information System (INIS)

    Cresotic acid (3-hydroxy-4-methylbenzoic acid) was proved be active in controlling wilt diseases of melon and cotton plants grown in the house. Soil drench with 200-1000 ppm cresotic acid induced 62-77 %, 69-79 % and 50-60 % protection against Fusarium oxysporum f.sp melonis (FOM) in melon, Fusarium oxysporum f.sp vasinfectum (FOV) and Verticillium dahliae in cotton, respectively. Since no inhibitory effect of cresotic acid on mycelial growth of these three fungual pathogens was observed in vitro, it is suggested that control of these wilt diseases with cresotic acid resulted from induced resistance. Cresotic acid induced resistance in melon plants not only against race 0, race 1, race 2 and race 1,2, but also against a mixture of these four races of FOM, suggesting a non-race- specific resistance. Level of induced resistance by cresotic acid against FOM depended on inoculum pressure applied to melon plants. At 25 day after inoculation with FOM, percentage protection induced by cresotic acid under low inoculum pressure retained a level of 51 %, while under high inoculum pressure percentage protection decreased to only 10 %. High concentrations of cresotic acid significantly reduced plant growth. Reduction in fresh weight of melon (36-51%) and cotton (42-71%) was obtained with 500-1000 ppm cresotic acid, while only less than 8% reduction occurred with 100-200 ppm. (author)

  13. Impact of Laurel Wilt, Caused by Raffaelea lauricola, on Leaf Gas Exchange and Xylem Sap Flow in Avocado, Persea americana.

    Science.gov (United States)

    Ploetz, Randy C; Schaffer, Bruce; Vargas, Ana I; Konkol, Joshua L; Salvatierra, Juanpablo; Wideman, Ronney

    2015-04-01

    Laurel wilt, caused by Raffaelea lauricola, is a destructive disease of avocado (Persea americana). The susceptibility of different cultivars and races was examined previously but more information is needed on how this host responds to the disease. In the present study, net CO2 assimilation (A), stomatal conductance of H2O (gs), transpiration (E), water use efficiency (WUE), and xylem sap flow rates were assessed in cultivars that differed in susceptibility. After artificial inoculation with R. lauricola, there was a close relationship between symptom development and reductions in A, gs, E, WUE, and mean daily sap flow in the most susceptible cultivar, 'Russell', and significantly greater disease and lower A, gs, E, WUE, and sap flow rates were usually detected after 15 days compared with the more tolerant 'Brogdon' and 'Marcus Pumpkin'. Significant differences in preinoculation A, gs, E, and WUE were generally not detected among the cultivars but preinoculation sap flow rates were greater in Russell than in Brogdon and Marcus Pumpkin. Preinoculation sap flow rates and symptom severity for individual trees were correlated at the end of an experiment (r=0.46), indicating that a plant's susceptibility to laurel wilt was related to its ability to conduct water. The potential management of this disease with clonal rootstocks that reduce sap flow rates is discussed. PMID:25496301

  14. Resistance breaking tomato spotted wilt virus isolates on resistant pepper varieties in Italy.

    Science.gov (United States)

    Crescenzi, A; Viggiano, A; Fanigliulo, A

    2013-01-01

    In spring 2012, resistance breaking (RB) isolates of tomato spotted wilt virus (TSWV) that overcome the resistance conferred by the Tsw gene in different pepper hybrids have been recovered in different locations in southern Italy (Campania and Apulia regions) in protected cultivation, about one month after transplant. The percentage of symptomatic plants was 5-10% and, only in particular cases of advanced stage of cultivation, it reached 30-50% at the end of cycle. All TSWV isolates induced similar systemic symptoms in all resistant infected pepper hybrids: yellowing or browning of apical leaves, which later become necrotic, long necrotic streakson stems, extending to the terminal shoots, complete necrosis of younger fruits and large necrotic streaks and spots on fruits formed after infection. On ripe fruits, yellow spots with concentric rings or necrotic streaks could be observed. Leaf extracts of these samples were tested in ELISA for the detection of TSWV, Cucumber mosaic virus (CMV), Tobacco mosaic virus (TMV), Tomato mosaic virus (ToMV), Impatiens necrotic spot virus (INSV), Potato virus Y (PVY), Alfalfa mosaic virus (AMV), Pepper mild mottle virus (PMMoV) and Pepper Mottle Virus (PepMoV). Only TSWV was detected in all the field samples tested. The correspondent virus isolates were inoculated mechanically and by Frankliniella occidentalis on to a set of different pepper and tomato hybrids, as well as on some herbaceous test plants, in order to investigate for their ability to overcome the resistance genes Tsw and Sw5, respectively. Tomato hybrids carrying the Sw5 gene were uninfected by all RB isolates, whereas all resistant pepper hybrids became systemically infected. RB isolates did not differ noticeably in transmission efficiency when they were tested with the thrips F. occidentalis. Obtained results demonstrate that evolved strains of TSWV have emerged, that they are able to overcome the Tsw resistance gene in pepper plants experimentally inoculated both

  15. The nucleoprotein of Tomato spotted wilt virus as protein tag for easy purification and enhanced production of recombinant proteins in plants

    NARCIS (Netherlands)

    Lacorte, C.C.; Ribeiro, S.G.; Lohuis, H.; Goldbach, R.W.; Prins, M.W.

    2007-01-01

    Upon infection, Tomato spotted wilt virus (TSWV) forms ribonucleoprotein particles (RNPs) that consist of nucleoprotein (N) and viral RNA. These aggregates result from the homopolymerization of the N protein, and are highly stable in plant cells. These properties feature the N protein as a potential

  16. First report of Fusarium decemcellulare causing inflorescence wilt, vascular and flower necrosis of rambutan (Nephelium lappaceum), longan (Dimocarpus longan) and mango (Mangifera indica)

    Science.gov (United States)

    Longan, mango and rambutan are very important fruit crops in Puerto Rico. During a disease survey in Puerto Rico conducted from 2008 to 2010, 50% of the inflorescences were affected with inflorescence wilt, flower and vascular necrosis at 70% of the fields of rambutan and longan at the USDA-ARS Rese...

  17. Dynamics of Colonization and Expression of Pathogenicity Related Genes in Fusarium oxysporum f.sp. ciceri during Chickpea Vascular Wilt Disease Progression.

    Directory of Open Access Journals (Sweden)

    Medha L Upasani

    Full Text Available Fusarium wilt caused by Fusarium oxysporum f.sp. ciceri (Foc is a constant threat to chickpea productivity in several parts of the world. Understanding the molecular basis of chickpea-Foc interaction is necessary to improve chickpea resistance to Foc and thereby the productivity of chickpea. We transformed Foc race 2 using green fluorescent protein (GFP gene and used it to characterize pathogen progression and colonization in wilt-susceptible (JG62 and wilt-resistant (Digvijay chickpea cultivars using confocal microscopy. We also employed quantitative PCR (qPCR to estimate the pathogen load and progression across various tissues of both the chickpea cultivars during the course of the disease. Additionally, the expression of several candidate pathogen virulence genes was analyzed using quantitative reverse transcriptase PCR (qRT-PCR, which showed their characteristic expression in wilt-susceptible and resistant chickpea cultivars. Our results suggest that the pathogen colonizes the susceptible cultivar defeating its defense; however, albeit its entry in the resistant plant, further proliferation is severely restricted providing an evidence of efficient defense mechanism in the resistant chickpea cultivar.

  18. Dynamics of Colonization and Expression of Pathogenicity Related Genes in Fusarium oxysporum f.sp. ciceri during Chickpea Vascular Wilt Disease Progression.

    Science.gov (United States)

    Upasani, Medha L; Gurjar, Gayatri S; Kadoo, Narendra Y; Gupta, Vidya S

    2016-01-01

    Fusarium wilt caused by Fusarium oxysporum f.sp. ciceri (Foc) is a constant threat to chickpea productivity in several parts of the world. Understanding the molecular basis of chickpea-Foc interaction is necessary to improve chickpea resistance to Foc and thereby the productivity of chickpea. We transformed Foc race 2 using green fluorescent protein (GFP) gene and used it to characterize pathogen progression and colonization in wilt-susceptible (JG62) and wilt-resistant (Digvijay) chickpea cultivars using confocal microscopy. We also employed quantitative PCR (qPCR) to estimate the pathogen load and progression across various tissues of both the chickpea cultivars during the course of the disease. Additionally, the expression of several candidate pathogen virulence genes was analyzed using quantitative reverse transcriptase PCR (qRT-PCR), which showed their characteristic expression in wilt-susceptible and resistant chickpea cultivars. Our results suggest that the pathogen colonizes the susceptible cultivar defeating its defense; however, albeit its entry in the resistant plant, further proliferation is severely restricted providing an evidence of efficient defense mechanism in the resistant chickpea cultivar. PMID:27227745

  19. Alpha-tocopherol and β-carotene in legume-grass mixtures as influenced by wilting, ensiling and type of silage additive

    DEFF Research Database (Denmark)

    Lindqvist, H; Nadeau, E; Jensen, Søren Krogh

    2012-01-01

    Effects of wilting, ensiling and type of additive on α-tocopherol and β-carotene contents in legume–grass mixtures were examined. Swards of birdsfoot trefoil + timothy (Bft + Ti), red clover + timothy (Rc + Ti) and red clover + meadow fescue (Rc + Mf) were harvested as a first regrowth in August...... 2005. Forage was wilted to a dry-matter (DM) content of 273 g kg−1 and ensiled without additive or with an inoculant or acid. Wilting decreased α-tocopherol concentration by 30% in the Bft + Ti mixture (P = 0·015). Untreated Bft + Ti silage had higher α-tocopherol content than red clover silages (56......·9 vs. 34·2 mg kg−1 DM; P = 0·015). The α-tocopherol concentration of Bft + Ti forages increased during ensiling from 41·1 mg kg−1 DM in wilted herbage to 56·9, 65·2 and 56·8 mg kg−1 DM in untreated, inoculated and acid-treated silage respectively (P = 0·015). The inoculant increased α-tocopherol...

  20. Evaluation of commercial formulations of entomopathogenic fungi to manage the redbay ambrosia beetle, vector of Laurel wilt, a lethal disease affecting avocados in Florida

    Science.gov (United States)

    The redbay ambrosia beetle (RAB), Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) vectors the fungal pathogen, Raffaelea lauricola, which causes laurel wilt (LW), a lethal disease of trees in the family Lauraceae, including the most commercially important crop in this family, avocado, Pe...

  1. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    -vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial......Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...

  2. Demonstrating Bacterial Flagella.

    Science.gov (United States)

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  3. Shuffling bacterial metabolomes

    OpenAIRE

    Thomason, Brendan; Read, Timothy D.

    2006-01-01

    Horizontal gene transfer (HGT) has a far more significant role than gene duplication in bacterial evolution. This has recently been illustrated by work demonstrating the importance of HGT in the emergence of bacterial metabolic networks, with horizontally acquired genes being placed in peripheral pathways at the outer branches of the networks.

  4. Vimentin in Bacterial Infections.

    Science.gov (United States)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection. PMID:27096872

  5. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  6. Vimentin in Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Tim N. Mak

    2016-04-01

    Full Text Available Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs. IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.

  7. 茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的识别与防治%ldentification and Control Methods of Eggplant Southern Blight, Damp-ing-off, Root Rot, Verticil-lium Wilt and Fusarium Wilt

    Institute of Scientific and Technical Information of China (English)

    高焕; 郑丹丹

    2012-01-01

    介绍了茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant southern blight, damping-off, root rot, verticillium wilt and fusarium wilt were introduced. Then the integrated control methods were put forward, which contained measures of agricultural control, chemical control and so on.

  8. Pantoea stewartii subsp. stewartii exhibits surface motility, which is a critical aspect of Stewart's wilt disease development on maize.

    Science.gov (United States)

    Herrera, Carmen M; Koutsoudis, Maria D; Wang, Xiaolei; von Bodman, Susanne B

    2008-10-01

    Pantoea stewartii subsp. stewartii is a plant-pathogenic bacterium that causes Stewart's vascular wilt in maize. The organism is taxonomically described as aflagellated and nonmotile. We recently showed that P. stewartii colonizes the xylem of maize as sessile, cell-wall-adherent biofilms. Biofilm formation is a developmental process that generally involves some form of surface motility. For that reason, we reexamined the motility properties of P. stewartii DC283 based on the assumption that the organism requires some form of surface motility for biofilm development. Here, we show that the organism is highly motile on agar surfaces. This motility is flagella dependent, shown by the fact that a fliC mutant, impaired in flagellin subunit synthesis, is nonmotile. Motility also requires the production of stewartan exopolysaccharide. Moreover, surface motility plays a significant role in the colonization of the plant host. PMID:18785831

  9. Analysis of Pineapple Mealybug Wilt Associated Virus -1 and -2 for Potential RNA Silencing Suppressors and Pathogenicity Factors

    Directory of Open Access Journals (Sweden)

    Kishore K. Dey

    2015-03-01

    Full Text Available Higher plants use RNA silencing to defend against viral infections. As a counter defense, plant viruses have evolved proteins that suppress RNA silencing. Mealybug wilt of pineapple (MWP, an important disease of pineapple, has been associated with at least three distinct viruses, Pineapple mealybug wilt associated virus -1, -2, and -3 (PMWaV-1, -2, and -3. Selected open reading frames (ORFs of PMWaV-1 and PMWaV-2 were screened for their local and systemic suppressor activities in Agrobacterium-mediated transient assays using green fluorescent protein (GFP in Nicotiana benthamiana. Results indicate that PMWaV-2 utilizes a multiple-component RNA silencing suppression mechanism. Two proteins, p20 and CP, target both local and systemic silencing in N. benthamiana, while the p22 and CPd proteins target only systemic silencing. In the related virus PMWaV-1, we found that only one of the encoded proteins, p61, had only systemic suppressor activity. Of all the proteins tested from both viruses, only the PMWaV-2 p20 protein suppressed local silencing induced by double-stranded RNA (dsRNA, but only when low levels of inducing dsRNA were used. None of the proteins analyzed could interfere with the short distance spread of silencing. We examined the mechanism of systemic suppression activity by investigating the effect of PMWaV-2-encoded p20 and CP proteins on secondary siRNAs. Our results suggest that the PMWaV-2 p20 and CP proteins block the systemic silencing signal by repressing production of secondary siRNAs. We also demonstrate that the PMWaV-2 p20 and p22 proteins enhanced the pathogenicity of Potato virus X in N. benthamiana.

  10. Assessment of Tolerance Level of some Cotton (Gossypium hirsutum L. Varieties against Verticillium wilt (Verticillium dahliae Kleb. Disease

    Directory of Open Access Journals (Sweden)

    Emine KARADEMIR

    2010-06-01

    Full Text Available The objective of this study was to assess the tolerance level of some cotton varieties against Verticillium wilt (Verticillium dahliae Kleb. disease. Verticillium wilt is one of the major constraint diseases of cotton production worldwide and also in Turkey. The study was carried out at the Southeastern Anatolia Agricultural Research Institute’s naturally infected experimental area during 2004-2006. In this study, 10 different commercial cotton varieties were used as plant material. The experimental design was a randomized complete-block with four replications. During the cotton growing season, foliar disease index (FDI, vascular disease index (VDI and vascular disease rate (VDR were observed in addition to seed cotton yield and some fiber quality characteristics. According to the results, it was determined that with regards to FDI, VDI and VDR, the most tolerant varieties were ‘GW-Teks’, ‘GW-Golda’ and ‘Carmen’, while the most sensitive varieties were ‘Maraş 92’, ‘Sayar 314’ and ‘Stoneville 453’. The other varieties had moderate tolerance levels. The highest seed cotton yield and lint yield were obtained from ‘DP-Deltaopal’ and ‘Stoneville 453’. These results showed that some sensitive varieties had high yield; the reason for this situation may be related with early or late occurrence of the disease. The result of this study indicated that ‘GW-Teks’, ‘GW-Golda’ and ‘Carmen’ varieties must be preferred for infected areas; on the other hand, ‘DP-Deltaopal’ and ‘Stoneville 453’ can be recommended and grown in uninfected areas. Additionally, ‘Carmen’, ‘GW-Teks’ and ‘GW-Golda’ varieties can be used as material for improving disease resistance in cotton breeding programs.

  11. Screening Fusarium wilt-resistant plants of Brazil banana (Musa spp., AAA) through EMS induced mutations from microcross sections cultural system

    International Nuclear Information System (INIS)

    Fusarium wilt is recognized as one of the most destructive diseases of banana worldwide. In this study, we screened Fusarium wilt-resistant plants of Brazil banana (Musa spp., AAA.) through EMS induced mutations from micro-cross sections cultural system. Micro-cross sections of pseudo stem of In vitro banana plantlets were treated with various concentrations of EMS for different duration, then were cultured in shoots induction medium. The results indicated that the survival index and the shoot forming index of the explants dropped with the increasing of EMS concentration and treatment duration. The optimal treatment for the concentration and duration was 300 mM and 60 min respectively. After the optimal treatment for 21 days, 2.2 regenerated shoots averagely could be produced from the explants of micro-cross sections, and the regenerated shoots were then cultured in shoots multiplying medium for 7 days. The stronger shoots were selected and transferred into roots medium for 4 weeks to obtain healthy regenerated plantlets. Hardened-regenerated plantlets were transplanted in green house for 2 months and 100 regenerated plants with vigorous root systems were selected for screening for Fusarium wilt resistance by using early screening technique. The initial disease symptom, yellowing in lower leaves, of susceptible plantlets could be observed after 2 weeks of inoculation with FOC race 4 and the extensive streaking on the most leaves was appeared after 2 months of inoculation. Only five plantlets survived and grew up healthily, which might be putative Fusarium wilt-resistant plants. Five sucks were selected from these 7-month-old putative resistant plants for screening the tolerance again and two suck- plants showed to be Fusarium wilt-resistant. Further studies on the Fusarium wilt tolerance of next generation of tissue cultural plants derived from these sucks and their genetic background are conducting. We concluded that the application of microcross sections of

  12. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  13. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  14. Induced Resistance of Endophyte XG-1 against Fusarium Wilt of Watermelon%内生菌XG-1对西瓜枯萎病诱导抗性的研究

    Institute of Scientific and Technical Information of China (English)

    孙正祥; 王丰; 周燚

    2013-01-01

    This experiment studied the induced resistance of endophytic bacterium XG-1 against Fusarium wilt of watermelon by taking the content variation of MDA and the activity variation of four defense enzymes including PAL,POD,PPO and CAT as the indexes. The results showed that the activities of the four defense enzymes in leaves of watermelon plants treated by bacterial suspension of endophyte XG-1 were all higher than the control. After the leaves were treated by XG-1 bacterial suspension and Fusarium oxysporum f. sp niveum (FON),the activity of PAL showed two peeks on the 4th day and the 10th day,l. 86 and 1. 52 times higher than the control, respectively; the activities of POD and PPO both exhibited the peek on the 4th day,increased by 52. 6% and 57. 1%,respectively; the activity of CAT exhibited the peek on the 5th day,increased by 56. 4%;MDA content firstly descended and then gradually ascended,falling to the lowest on the 4th day,dropped by 33. 1%. The results suggest that induced resistance is one of the important mechanisms by strain XG-1 in control of watermelon Fusarium wilt.%以苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)、过氧化氢酶(CAT)4种防御酶的活性变化以及丙二醛(MDA)的含量变化作为指标,研究内生菌XG-1对西瓜枯萎病的诱导抗性,为阐明XG-1的作用机制及其开发应用提供理论依据.结果表明:经内生菌XG-1菌悬液处理后,西瓜苗叶片的PAL、POD、PPO及CAT活性均高于清水对照.同时接种XG-1菌悬液和西瓜枯萎病菌(Fusarium oxysporum f.sp niveum,FON)的叶片,PAL活性在接种后第4天、第10天出现2次高峰,分别比对照增加1.86倍和1.52倍;POD和PPO活性均在第4天达到最高峰,分别比对照提高52.6%和57.1%;CAT活性在第5天时达到最高峰,比对照提高56.4%.同时接种XG-1菌悬液和枯萎病菌FON后,西瓜苗叶片的MDA含量呈先下降后逐渐上升趋势,第4天时达到最低值,比对照下降33.1%.由此

  15. Calibrating bacterial evolution

    OpenAIRE

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal appl...

  16. Controle biológico da murcha bacteriana do tomateiro, por Pseudomonas spp. fluorescentes Biological control of bacterial wilt of tomato by fluorescent Pseudomonas spp

    OpenAIRE

    Ana Rosa Peixoto

    1997-01-01

    Esta revisão bibliográfica teve como objetivo avaliar o potencial de antagonismo de espécies de Pseudomonas fluorescentes a Pseudomonas solanacearum, agente causal da murcha bacteriana do tomateiro. Devido a dificuldade encontrada nas estratégias utilizadas para o controle da Murcha Bacteriana por meio de métodos convencionais, alguns outros tem sido estudados, como o uso de microrganismos benéficos. As rizobactérias vem proporcionando solução viável a algumas doenças consideradas de difícil ...

  17. A New Record of Candida kashinagacola (Synonym Ambrosiozyma kashinagacola) from Galleries of Platypus koryoensis, the Oak Wilt Disease Vector, in Korea

    OpenAIRE

    Suh, Dong Yeon; Kim, Seong Hwan; Son, Seung Yeol; Seo, Sang Tae; Kim, Kyung Hee

    2013-01-01

    The ambrosia beetle, Platypus koryoensis, is an economically important pest affecting oak trees in Korea. Candida kashinagacola was isolated from galleries of the beetle in oak wood and identified by analyses of morphology, physiological properties, and nucleotide sequence of the large subunit ribosomal DNA. This is the first report on Candida species associated with oak wilt disease vectored by the ambrosia beetle, Platypus koryoensis, in Korea.

  18. A New Record of Candida kashinagacola (Synonym Ambrosiozyma kashinagacola) from Galleries of Platypus koryoensis, the Oak Wilt Disease Vector, in Korea.

    Science.gov (United States)

    Suh, Dong Yeon; Kim, Seong Hwan; Son, Seung Yeol; Seo, Sang Tae; Kim, Kyung Hee

    2013-12-01

    The ambrosia beetle, Platypus koryoensis, is an economically important pest affecting oak trees in Korea. Candida kashinagacola was isolated from galleries of the beetle in oak wood and identified by analyses of morphology, physiological properties, and nucleotide sequence of the large subunit ribosomal DNA. This is the first report on Candida species associated with oak wilt disease vectored by the ambrosia beetle, Platypus koryoensis, in Korea. PMID:24493947

  19. A new Capsicum baccatum accession shows tolerance to wild-type and resistance-breaking isolates of Tomato spotted wilt virus

    OpenAIRE

    Soler Aleixandre, Salvador; DEBRECZENI, DIANA ELVIRA; Vidal, Eduardo; Aramburu, José; López Del Rincón, Carmelo; Galipienso Torregrosa, Luis; RUBIO MIGUELEZ, LUIS

    2015-01-01

    [EN] Tomato spotted wilt virus (TSWV) causes economically important losses in many crops, worldwide. In pepper (Capsicum annuum), the best method for disease control has been breeding resistant cultivars by introgression of gene Tsw from Capsicum chinense. However, this resistance has two drawbacks: (a) it is not efficient if plants are infected at early growth stages and under prolonged high temperatures, and (b) it is rapidly overcome by TSWV evolution. In this work, we se...

  20. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine

    OpenAIRE

    Pouzoulet, Jérôme; Pivovaroff, Alexandria L.; Santiago, Louis S.; Rolshausen, Philippe E.

    2014-01-01

    This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different ...

  1. Modified Primers for the Identification of Nonpathogenic Fusarium oxysporum Isolates That Have Biological Control Potential against Fusarium Wilt of Cucumber in Taiwan

    OpenAIRE

    Chaojen Wang; Yisheng Lin; Yinghong Lin; Wenhsin Chung

    2013-01-01

    Previous investigations demonstrated that Fusarium oxysporum (Fo), which is not pathogenic to cucumbers, could serve as a biological control agent for managing Fusarium wilt of cucumber caused by Fo f. sp. cucumerinum (Foc) in Taiwan. However, thus far it has not been possible to separate the populations of pathogenic Fo from the nonpathogenic isolates that have biological control potential through their morphological characteristics. Although these two populations can be distinguished from o...

  2. 黄瓜枯萎病生物防治策略研究进展%Research Progress in Biological Control Strategies for Fusarium Wilt of Cucumber

    Institute of Scientific and Technical Information of China (English)

    蒲子婧; 张艳菊; 刘东; 代丽婷; 王文博

    2011-01-01

    黄瓜枯萎病是黄瓜栽培过程中经常发生的一种土传性病害,给农业生产造成了严重损失.近年来,利用生物方法防治黄瓜枯萎病取得了较大进展,并呈现多样化的发展趋势,已成为防治该病害的重要且有效手段.本文从利用拮抗微生物和植物化感作用两方面对国内外黄瓜枯萎病生物防治的主要手段进行了总结,概述了各种生防因子的作用机制及主要研究成果,并提出应综合考虑当地实际情况,利用植物化感作用及生防作用物自身特点,因地制宜地制定黄瓜枯萎病生物防治策略.%Fusarium wilt is a common disease in cucumber ( Cucumis sativus L. ) culture, which has brought severe loss to agriculture production. In recent years, great progress has been made in controlling this disease by biological control method and a diversified development trend is presented. Bio-control has become an important and effective mean against fusarium wilt in cucumber. This study summarizes the bio-control method for cucumber fusarium wilt both in China and abroad from two aspects of utilizing antagonistic microorganisms and plant allelopathy. It also briefly introduces the functional mechanism of various bio-control factors and the main research achievements, and puts forward suggestions of taking comprehensive consideration according to local condition and developing bio-control strategy to tackle with cucumber fusarium wilt.

  3. Effect of pseudobactin 358 production by Pseudomonas putida WCS358 on suppression of fusarium wilt of carnations by nonpathogenic Fusarium oxysporum Fo47.

    OpenAIRE

    Lemanceau, P.; Bakker, P A; de Kogel, W.J.; Alabouvette, C.; Schippers, B.

    1992-01-01

    Nonpathogenic Fusarium oxysporum Fo47b10 combined with Pseudomonas putida WCS358 efficiently suppressed fusarium wilt of carnations grown in soilless culture. This suppression was significantly higher than that obtained by inoculation of either antagonistic microorganism alone. The increased suppression obtained by Fo47b10 combined with WCS358 only occurred when Fo47b10 was introduced at a density high enough (at least 10 times higher than that of the pathogen) to be efficient on its own. P. ...

  4. Pseudomonas fluorescens Induced Enzymological Changes in Banana Roots (Cv. Rasthali) against Fusarium Wilt Disease

    OpenAIRE

    Saravanan, T.; Bhaskaran, R.; M. Muthusamy

    2004-01-01

    Pseudomonas fluorescens isolated from banana rhizosphere reduced the vascular discolouration associated with Fusarium wilt disease and induced the accumulation of resistance associated enzymes in roots. The banana roots inoculated with talc based formulation of P. fluorescens at 10 g / plant had minimum vascular discolouration index when compared to pathogen Fusarium oxysporum f.sp. cubense alone inoculated roots. The resistance associated enzymes viz., peroxidase and polyphenol oxidase activ...

  5. Differential expression of tomato spotted wilt virus-derived viral small RNAs in infected commercial and experimental host plants.

    Directory of Open Access Journals (Sweden)

    Neena Mitter

    Full Text Available BACKGROUND: Viral small RNAs (vsiRNAs in the infected host can be generated from viral double-stranded RNA replicative intermediates, self-complementary regions of the viral genome or from the action of host RNA-dependent RNA polymerases on viral templates. The vsiRNA abundance and profile as well as the endogenous small RNA population can vary between different hosts infected by the same virus influencing viral pathogenicity and host response. There are no reports on the analysis of vsiRNAs of Tomato spotted wilt virus (TSWV, a segmented negative stranded RNA virus in the family Bunyaviridae, with two of its gene segments showing ambisense gene arrangement. The virus causes significant economic losses to numerous field and horticultural crops worldwide. PRINCIPAL FINDINGS: Tomato spotted wilt virus (TSWV-specific vsiRNAs were characterized by deep sequencing in virus-infected experimental host Nicotiana benthamiana and a commercial, susceptible host tomato. The total small (s RNA reads in TSWV-infected tomato sample showed relatively equal distribution of 21, 22 and 24 nt, whereas N. benthamiana sample was dominated by 24 nt total sRNAs. The number of vsiRNA reads detected in tomato was many a magnitude (~350:1 higher than those found in N. benthamiana, however the profile of vsiRNAs in terms of relative abundance 21, 22 and 24 nt class size was similar in both the hosts. Maximum vsiRNA reads were obtained for the M RNA segment of TSWV while the largest L RNA segment had the least number of vsiRNAs in both tomato and N. benthamiana. Only the silencing suppressor, NSs, of TSWV recorded higher antisense vsiRNA with respect to the coding frame among all the genes of TSWV. SIGNIFICANCE: Details of the origin, distribution and abundance of TSWV vsiRNAs could be useful in designing efficient targets for exploiting RNA interference for virus resistance. It also has major implications toward our understanding of the differential processing of vsi

  6. Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide.

    Science.gov (United States)

    Abdel-Monaim, Montaser Fawzy

    2013-03-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the

  7. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  8. INIBAP 引进香蕉种质资源对枯萎病的抗性评价%Fusarium Wilt Resistance of Banana Germplasm Introduced from INIBAP

    Institute of Scientific and Technical Information of China (English)

    冯慧敏; 张俊; 王志双; 徐小雄; 陈友; 王沛政; 武耀廷

    2014-01-01

    香蕉枯萎病己成为香蕉的毁灭性病害。该病属于土传性病害,扩散蔓延速度快,难于进行生物控制、药物防治及轮作、浸田等常用防治方法的防治。因此,防治香蕉枯萎病的最佳方法是进行香蕉遗传改良,培育抗病品种。选用从 INIBAP[(International Network for the Improvement of Bnana and Plantain,国际香(大)蕉改良网络)]引进的42份香蕉种质资源,采用伤根侵染法,用含2×106个孢子/L的香蕉枯萎病1号和4号小种菌液分别对42份香蕉幼苗进行处理,筛选抗香蕉枯萎病种质。结果表明:在侵染1号小种时,7份材料表现高感,13份感病,22份中抗,无高抗;在侵染4号小种时,25份材料表现高感,12份感病,5份中抗,无高抗。综合分析显示, M11和 M25对枯萎病1号和4号小种均表现中抗。%Banana fusarium wilt has become a devastating disease of bananas. The disease is a soil borne disease, spread fast, particularly difficult to control, which include biological control, drug control, rotation and leaching field. Therefore, the fundamental way to control banana fusarium wilt is genetic improvement, breeding disease resistant varieties. This paper selected 42 copies of banana germplasm resources which introduced from INIBAP (International Network for the Improvement of Bnana and Plantain), using method of root wound infection, treated the banana seedlings with fusarium wilt disease of No.1 and No. 4 physiological races which containing 2 ×106 spores /L respectively, to assessed the resistance to fusarium wilt disease. The results showed that: 7 accessions exhibited highly susceptible to physiological races No.1 of fusarium wilt disease, 13 accessions exhibited susceptible, 22 accessions exhibited intermediate resistance, no highly resistance. On the 0ther hand, 25 accessions exhibited highly susceptible to physiological races No.4 of fusarium wilt disease, 12 accessions exhibited susceptible, 5 accessions exhibited

  9. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  10. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria.......Biofilm resilience poses major challenges to the development of novel antimicrobial agents. Biofilm bacteria can be considered small groups of “Special Forces” capable of infiltrating the host and destroying important components of the cellular defense system with the aim of crippling the host...

  11. Small RNA profiles of wild-type and silencing suppressor-deficient tomato spotted wilt virus infected Nicotiana benthamiana.

    Science.gov (United States)

    Margaria, Paolo; Miozzi, Laura; Rosa, Cristina; Axtell, Michael J; Pappu, Hanu R; Turina, Massimo

    2015-10-01

    Tospoviruses are plant-infecting viruses belonging to the family Bunyaviridae. We used a collection of wild-type, phylogenetically distinct tomato spotted wilt virus isolates and related silencing-suppressor defective mutants to study the effects on the small RNA (sRNA) accumulation during infection of Nicotiana benthamiana. Our data showed that absence of a functional silencing suppressor determined a marked increase of the total amount of viral sRNAs (vsRNAs), and specifically of the 21 nt class. We observed a common under-representation of vsRNAs mapping to the intergenic region of S and M genomic segments, and preferential mapping of the reads against the viral sense open reading frames, with the exception of the NSs gene. The NSs-mutant strains showed enrichment of NSm-derived vsRNA compared to the expected amount based on gene size. Analysis of 5' terminal nucleotide preference evidenced a significant enrichment in U for the 21 nt- and in A for 24 nt-long endogenous sRNAs in all the samples. Hotspot analysis revealed a common abundant accumulation of reads at the 5' end of the L segment, mostly in the antiviral sense, for the NSs-defective isolates, suggesting that absence of the silencing suppressor can influence preferential targeting of the viral genome. PMID:26047586

  12. Efficacy of Micro Nutrients on Banana fusarium Wilt. (Fusarium oxysporum f. sp. cubense and it's Synergistic Action with Trichoderma viride

    Directory of Open Access Journals (Sweden)

    K. SANJEEV

    2008-08-01

    Full Text Available In the present investigations, efficacy of micro nutrients viz., (calcium nitrate, ammonium sulphate, copper sulphate, potassium chloride, sodium chloride, borax, ferrous sulphate and zinc sulphate against Fusarium oxysporum f. sp. cubense causing panama wilt of banana were studied. The results of experiment revealed that among the micro nutrients used, borax @ 500 and 750 ppm completely inhibited the mycelial growth of Fusarium oxysporum f. sp. cubense followed by zinc sulphate (47.3, 42.7, 31.0 and 14.3 mm at 100, 250, 500 and 750 ppm respectively. The incorporation of borax in solid medium at higher concentrations viz., 500 and 750 ppm., significantly decreased the mycelial growth of the T.viride, whereas the sporulation capacity of T.viride (207.48 x 108 spores/ sq.cm @ 500 ppm was found to be maximised by the addition of borax. In general, the antagonist was compatible with borax at low concentrations. The maximum inhibition of mycelial growth of F. oxysporum f. sp cubense was found in borax and T. viride inoculated medium.

  13. Foliar levels of rare earth elements and thorium in coconut palm in relation to root (wilt)-disease

    International Nuclear Information System (INIS)

    Concentrations of major nutrients and micronutrients, rare earth elements (REEs), Th and nutrient/REE ratios in the leaves of diseased and apparently healthy coconut palms of the root (wilt)-disease-affected tract and healthy palms of the disease-free tract, covering three major soil types of Kerala, namely alluvial (entisols), laterite (ultisols), and sandy (entisols), were examined in relation to the disease. Accumulation of major nutrients, especially K, was generally observed in the leaves of diseased palms. Mg content of leaves of palms growing on laterite soil in disease-affected tract was lower than than of palms in the disease-free tract. The leaf concentrations of La, Ce, Pr, Nd, Sm, Gd and Th did not show significant differences between healthy and diseased palms. The only exception to this trend was Gd whose concentration was less in the diseased and apparently healthy palms growing on laterite soil of the disease-endemic area than that in the healthy palms of the disease-free area. Some of the essential plant nutrients (EPN)/La, and EPN/Ce ratios were significantly different in palms of the disease-affected tract compared to that in palms of the disease-free tract indicating imbalances in the relative concentrations of EPNs and REEs. These results call for more detailed study of the geochemical differences between the disease-affected and disease-free tracts for identification of the soil chemical factors associated with the incidence of the disease. (author)

  14. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula—A Focus on Responses to Fusarium Wilt Disease

    Directory of Open Access Journals (Sweden)

    Louise F. Thatcher

    2016-02-01

    Full Text Available Jasmonate (JA-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume–F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana–F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula-–F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection.

  15. A Study on Tulip Bulb Wilt%郁金香种球枯萎病研究

    Institute of Scientific and Technical Information of China (English)

    常瑾; 郭新军

    2011-01-01

    郁金香枯萎病是贮藏期郁金香鳞茎上发生普遍、危害严重的病害之一.对病原菌Fusarium proliferatum的生物学特性及六种杀菌剂对其的抑制作用进行了研究,生物学特性实验表明:该菌在5~35℃,pH 3~9条件下均能生长,最适生长温度为25℃,最适生长pH为7.室内药剂筛选结果表明:430 g/L戊唑醇悬浮剂对该菌菌丝生长的抑制效果最好.%Tulip wilt is one of the very harmful and common diseases that impair tulip bulbs.We made a study of the biological characteristics of Fusarium proliferatum and the inhibitory effect of six fungicides.The experimental results show that the suitable conditions for the growth of pathogen is 5~35℃ and pH 3~9.The favorable environment for its growth is 25℃ and pH7.Fungicide results show that 430 g/L tebuconazole on mycelial growth inhibition is the best solution.

  16. Bacterial extracellular lignin peroxidase

    Science.gov (United States)

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

    A newly discovered lignin peroxidase enzyme is provided. The enzyme is obtained from a bacterial source and is capable of degrading the lignin portion of lignocellulose in the presence of hydrogen peroxide. The enzyme is extracellular, oxidative, inducible by lignin, larch wood xylan, or related substrates and capable of attacking certain lignin substructure chemical bonds that are not degradable by fungal lignin peroxidases.

  17. Bacterial Skin Infections

    Science.gov (United States)

    ... or scraped, the injury should be washed with soap and water and covered with a sterile bandage. Petrolatum may be applied to open areas to keep the tissue moist and to try to prevent bacterial invasion. Doctors recommend that people do not use ...

  18. Bacterial microflora of nectarines

    Science.gov (United States)

    Microflora of fruit surfaces has been the best source of antagonists against fungi causing postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus fruit. We characterized bacterial microflora on nectarine f...

  19. Heme uptake in bacterial pathogens

    OpenAIRE

    Contreras, Heidi; Chim, Nicholas; Credali, Alfredo; Goulding, Celia W.

    2014-01-01

    Iron is an essential nutrient for the survival of organisms. Bacterial pathogens possess specialized pathways to acquire heme from their human hosts. In this review, we present recent structural and biochemical data that provide mechanistic insights into several bacterial heme uptake pathways, encompassing the sequestration of heme from human hemoproteins to secreted or membrane-associated bacterial proteins, the transport of heme across bacterial membranes, and the degradation of heme within...

  20. Evolutionary transitions in bacterial symbiosis

    OpenAIRE

    Sachs, Joel L.; Skophammer, Ryan G.; Regus, John U.

    2011-01-01

    Diverse bacterial lineages form beneficial infections with eukaryotic hosts. The origins, evolution, and breakdown of these mutualisms represent important evolutionary transitions. To examine these key events, we synthesize data from diverse interactions between bacteria and eukaryote hosts. Five evolutionary transitions are investigated, including the origins of bacterial associations with eukaryotes, the origins and subsequent stable maintenance of bacterial mutualism with hosts, the captur...

  1. 万寿菊提取物对番茄枯萎病抑制作用研究%Inhibitory Effects of Tagetes patula on Tomato Fusariurn Wilt

    Institute of Scientific and Technical Information of China (English)

    李鲜花; 刘永华

    2011-01-01

    [ Objective ] The study aimed to explore a new way for the control of Tomato Fusarium Wilt. [ Method ] Different solvents were used to prepare the extracts of Tagetes patula, and the inhibitory effects of different extraction solvents and different extraction parts of T. patula against Tomato Fusarium Wilt were compared. [ Result] Among different solvent extracts of T. patula, chloroform extracts had the strongest inhibitory effects against the growth of the pathogen; among the chloroform extracts from different parts of T. patula, root extract had the most obvious inhibitory effect against the disease, followed by flower and leaf extracts, and the inhibitory0 effect of stem extract was the weakest.[ Conclusion ] The active components of T. patula have inhibitory effect against Tomato Fusarium Wilt, and the plant has good development prospects and application value.%[目的]为防治番茄枯萎病提供新途径.[方法]采用不同溶剂制备万寿菊提取物,比较不同提取物对番茄枯萎病的抑制作用.[结果]在万寿菊不同溶剂提取物中,以氯仿提取物对番茄枯萎病菌生长的抑制效果最好;万寿菊不同部位氯仿提取物中,根部提取物对番茄枯萎病的抑制作用最明显,花、叶片提取物次之,茎提取物抑制作用最弱.[结论]万寿菊中含有的活性成分对番茄枯萎病有抑制作用,具有良好的开发前景和应用价值.

  2. Ex-Ante Economic Impact Assessment of Genetically Modified Banana Resistant to Xanthomonas Wilt in the Great Lakes Region of Africa

    Science.gov (United States)

    Ainembabazi, John Herbert; Tripathi, Leena; Rusike, Joseph; Abdoulaye, Tahirou; Manyong, Victor

    2015-01-01

    Background Credible empirical evidence is scanty on the social implications of genetically modified (GM) crops in Africa, especially on vegetatively propagated crops. Little is known about the future success of introducing GM technologies into staple crops such as bananas, which are widely produced and consumed in the Great Lakes Region of Africa (GLA). GM banana has a potential to control the destructive banana Xanthomonas wilt disease. Objective To gain a better understanding of future adoption and consumption of GM banana in the GLA countries which are yet to permit the production of GM crops; specifically, to evaluate the potential economic impacts of GM cultivars resistant to banana Xanthomonas wilt disease. Data Sources The paper uses data collected from farmers, traders, agricultural extension agents and key informants in the GLA. Analysis We analyze the perceptions of the respondents about the adoption and consumption of GM crop. Economic surplus model is used to determine future economic benefits and costs of producing GM banana. Results On the release of GM banana for commercialization, the expected initial adoption rate ranges from 21 to 70%, while the ceiling adoption rate is up to 100%. Investment in the development of GM banana is economically viable. However, aggregate benefits vary substantially across the target countries ranging from US$ 20 million to 953 million, highest in countries where disease incidence and production losses are high, ranging from 51 to 83% of production. Conclusion The findings support investment in the development of GM banana resistant to Xanthomonas wilt disease. The main beneficiaries of this technology development are farmers and consumers, although the latter benefit more than the former from reduced prices. Designing a participatory breeding program involving farmers and consumers signifies the successful adoption and consumption of GM banana in the target countries. PMID:26414379

  3. Modified primers for the identification of nonpathogenic Fusarium oxysporum isolates that have biological control potential against Fusarium wilt of cucumber in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chaojen Wang

    Full Text Available Previous investigations demonstrated that Fusarium oxysporum (Fo, which is not pathogenic to cucumbers, could serve as a biological control agent for managing Fusarium wilt of cucumber caused by Fo f. sp. cucumerinum (Foc in Taiwan. However, thus far it has not been possible to separate the populations of pathogenic Fo from the nonpathogenic isolates that have biological control potential through their morphological characteristics. Although these two populations can be distinguished from one another using a bioassay, the work is laborious and time-consuming. In this study, a fragment of the intergenic spacer (IGS region of ribosomal DNA from an Fo biological control agent, Fo366, was PCR-amplified with published general primers, FIGS11/FIGS12 and sequenced. A new primer, NPIGS-R, which was designed based on the IGS sequence, was paired with the FIGS11 primer. These primers were then evaluated for their specificity to amplify DNA from nonpathogenic Fo isolates that have biological control potential. The results showed that the modified primer pair, FIGS11/NPIGS-R, amplified a 500-bp DNA fragment from five of seven nonpathogenic Fo isolates. These five Fo isolates delayed symptom development of cucumber Fusarium wilt in greenhouse bioassay tests. Seventy-seven Fo isolates were obtained from the soil and plant tissues and then subjected to amplification using the modified primer pair; six samples showed positive amplification. These six isolates did not cause symptoms on cucumber seedlings when grown in peat moss infested with the isolates and delayed disease development when the same plants were subsequently inoculated with a virulent isolate of Foc. Therefore, the modified primer pair may prove useful for the identification of Fo isolates that are nonpathogenic to cucumber which can potentially act as biocontrol agents for Fusarium wilt of cucumber.

  4. Ex-Ante Economic Impact Assessment of Genetically Modified Banana Resistant to Xanthomonas Wilt in the Great Lakes Region of Africa.

    Directory of Open Access Journals (Sweden)

    John Herbert Ainembabazi

    Full Text Available Credible empirical evidence is scanty on the social implications of genetically modified (GM crops in Africa, especially on vegetatively propagated crops. Little is known about the future success of introducing GM technologies into staple crops such as bananas, which are widely produced and consumed in the Great Lakes Region of Africa (GLA. GM banana has a potential to control the destructive banana Xanthomonas wilt disease.To gain a better understanding of future adoption and consumption of GM banana in the GLA countries which are yet to permit the production of GM crops; specifically, to evaluate the potential economic impacts of GM cultivars resistant to banana Xanthomonas wilt disease.The paper uses data collected from farmers, traders, agricultural extension agents and key informants in the GLA.We analyze the perceptions of the respondents about the adoption and consumption of GM crop. Economic surplus model is used to determine future economic benefits and costs of producing GM banana.On the release of GM banana for commercialization, the expected initial adoption rate ranges from 21 to 70%, while the ceiling adoption rate is up to 100%. Investment in the development of GM banana is economically viable. However, aggregate benefits vary substantially across the target countries ranging from US$ 20 million to 953 million, highest in countries where disease incidence and production losses are high, ranging from 51 to 83% of production.The findings support investment in the development of GM banana resistant to Xanthomonas wilt disease. The main beneficiaries of this technology development are farmers and consumers, although the latter benefit more than the former from reduced prices. Designing a participatory breeding program involving farmers and consumers signifies the successful adoption and consumption of GM banana in the target countries.

  5. [Bacterial diseases of rape].

    Science.gov (United States)

    Zakharova, O M; Mel'nychuk, M D; Dankevych, L A; Patyka, V P

    2012-01-01

    Bacterial destruction of the culture was described and its agents identified in the spring and winter rape crops. Typical symptoms are the following: browning of stem tissue and its mucilagization, chlorosis of leaves, yellowing and beginning of soft rot in the place of leaf stalks affixion to stems, loss of pigmentation (violet). Pathogenic properties of the collection strains and morphological, cultural, physiological, and biochemical properties of the agents of rape's bacterial diseases isolated by the authors have been investigated. It was found that all the isolates selected by the authors are highly or moderately aggressive towards different varieties of rape. According to the complex of phenotypic properties 44% of the total number of isolates selected by the authors are related to representatives of the genus Pseudomonas, 37% - to Xanthomonas and 19% - to Pectobacterium. PMID:23293826

  6. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... cell. These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  7. Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus.

    Directory of Open Access Journals (Sweden)

    Pamella Akoth Ogada

    Full Text Available Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant, as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector's life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis' life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector-based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector.

  8. Identification of causal agent for sunflower Verticillium wilt%向日葵黄萎病病原鉴定

    Institute of Scientific and Technical Information of China (English)

    裴旭; 杨柳青; 徐鑫; 景岚

    2012-01-01

    从黑龙江、内蒙古东部和西部、河北、陕西、宁夏、新疆向日葵黄萎病发生严重的地块采集有典型症状的200多个病株进行病原物分离,通过常规组织分离法分离到120个菌株.在PDA培养基上,其菌落表现黑色、白色及灰白色.显微镜下观察其营养菌丝透明、有分隔,呈轮状分枝;分生孢子卵圆或椭圆形、单细胞;大多产生黑色微菌核.提取DNA并进行ITS序列分析(ITS1/ITS4),证实该120个向日葵黄萎病菌株均为轮枝孢属大丽轮枝菌(Verticillium dahliae Kleb.).%More than 200 diseased plants having shown typical Verticillium wilt symptoms were collected from Heilongjiang, Inner Mongolia Autonomous Region, Hebei, Shanxi, Shaanxi, Ningxia Hui Autonomous Region and the Xinjiang Uygur Autonomous Region. 120 strains obtained by tissue isolation technics were identified. On PDA, the colonies showed black, white or gray white. The vegetative mycelium was hyaline and septate. Conidia were o-void or ellipsoid and single - celled. They were borne on phialides, which were produced in a whorl around each conidiophore. Most of these isolates produced black microsclerotia. Genomic DNA was extracted and used as a template for amplification of the internal transcribed spacer (ITS) region of rDNA with primer pair ITS1/ITS4. All of the 120 strains were identified as Verticillium dahliae Kleb.

  9. Modified expression of alternative oxidase in transgenic tomato and petunia affects the level of tomato spotted wilt virus resistance

    Directory of Open Access Journals (Sweden)

    Ma Hao

    2011-10-01

    Full Text Available Abstract Background Tomato spotted wilt virus (TSWV has a very wide host range, and is transmitted in a persistent manner by several species of thrips. These characteristics make this virus difficult to control. We show here that the over-expression of the mitochondrial alternative oxidase (AOX in tomato and petunia is related to TSWV resistance. Results The open reading frame and full-length sequence of the tomato AOX gene LeAox1au were cloned and introduced into tomato 'Healani' and petunia 'Sheer Madness' using Agrobacterium-mediated transformation. Highly expressed AOX transgenic tomato and petunia plants were selfed and transgenic R1 seedlings from 10 tomato lines and 12 petunia lines were used for bioassay. For each assayed line, 22 to 32 tomato R1 progeny in three replications and 39 to 128 petunia progeny in 13 replications were challenged with TSWV. Enzyme-Linked Immunosorbent Assays showed that the TSWV levels in transgenic tomato line FKT4-1 was significantly lower than that of wild-type controls after challenge with TSWV. In addition, transgenic petunia line FKP10 showed significantly less lesion number and smaller lesion size than non-transgenic controls after inoculation by TSWV. Conclusion In all assayed transgenic tomato lines, a higher percentage of transgenic progeny had lower TSWV levels than non-transgenic plants after challenge with TSWV, and the significantly increased resistant levels of tomato and petunia lines identified in this study indicate that altered expression levels of AOX in tomato and petunia can affect the levels of TSWV resistance.

  10. Predictive Models for Tomato Spotted Wilt Virus Spread Dynamics, Considering Frankliniella occidentalis Specific Life Processes as Influenced by the Virus

    Science.gov (United States)

    Ogada, Pamella Akoth; Moualeu, Dany Pascal; Poehling, Hans-Michael

    2016-01-01

    Several models have been studied on predictive epidemics of arthropod vectored plant viruses in an attempt to bring understanding to the complex but specific relationship between the three cornered pathosystem (virus, vector and host plant), as well as their interactions with the environment. A large body of studies mainly focuses on weather based models as management tool for monitoring pests and diseases, with very few incorporating the contribution of vector’s life processes in the disease dynamics, which is an essential aspect when mitigating virus incidences in a crop stand. In this study, we hypothesized that the multiplication and spread of tomato spotted wilt virus (TSWV) in a crop stand is strongly related to its influences on Frankliniella occidentalis preferential behavior and life expectancy. Model dynamics of important aspects in disease development within TSWV-F. occidentalis-host plant interactions were developed, focusing on F. occidentalis’ life processes as influenced by TSWV. The results show that the influence of TSWV on F. occidentalis preferential behaviour leads to an estimated increase in relative acquisition rate of the virus, and up to 33% increase in transmission rate to healthy plants. Also, increased life expectancy; which relates to improved fitness, is dependent on the virus induced preferential behaviour, consequently promoting multiplication and spread of the virus in a crop stand. The development of vector–based models could further help in elucidating the role of tri-trophic interactions in agricultural disease systems. Use of the model to examine the components of the disease process could also boost our understanding on how specific epidemiological characteristics interact to cause diseases in crops. With this level of understanding we can efficiently develop more precise control strategies for the virus and the vector. PMID:27159134

  11. Loop mediated isothermal amplification (LAMP) assay for detection of coconut root wilt disease and arecanut yellow leaf disease phytoplasma.

    Science.gov (United States)

    Nair, Smita; Manimekalai, Ramaswamy; Ganga Raj, Palliyath; Hegde, Vinayaka

    2016-07-01

    The coconut root wilt disease (RWD) and the arecanut yellow leaf disease (YLD) are two major phytoplasma associated diseases affecting palms in South India. Greatly debilitating the palm health, these diseases cause substantial yield reduction and economic loss to farmers. A rapid and robust diagnostic technique is crucial in efficient disease management. We established phytoplasma 16S rDNA targeted loop mediated isothermal amplification (LAMP) and real time LAMP based diagnostics for coconut RWD and arecanut YLD. The LAMP reaction was set at 65 °C and end point detection made using hydroxynaphthol blue (HNB) and agarose gel electrophoresis. Molecular typing of LAMP products were made with restriction enzyme HpyCH4 V. Conventional PCR with LAMP external primers and sequencing of amplicons was carried out. Real time LAMP was performed on the Genei II platform (Optigene Ltd., UK). An annealing curve analysis was programmed at the end of the incubation to check the fidelity of the amplicons. The phytoplasma positive samples produced typical ladder like bands on agarose gel, showed colour change from violet to blue with HNB and produced unique annealing peak at 85 ± 0.5 °C in the real time detection. Restriction digestion produced predicted size fragments. Sequencing and BLASTN analysis confirmed that the amplification corresponded to phytoplasma 16S rRNA gene. LAMP method devised here was found to be more robust compared to conventional nested PCR and hence has potential applications in detection of phytoplasma from symptomatic palm samples and in rapid screening of healthy seedlings. PMID:27263003

  12. Supramolecular bacterial systems

    OpenAIRE

    Sankaran, Shrikrishnan

    2015-01-01

    For nearly over a decade, a wide variety of dynamic and responsive supramolecular architectures have been investigated and developed to address biological systems. Since the non-covalent interactions between individual molecular components in such architectures are similar to the interactions found in living systems, it was possible to integrate chemically-synthesized and naturally-occurring components to create platforms with interesting bioactive properties. Bacterial cells and recombinant ...

  13. Bacterial transformation of terpenoids

    International Nuclear Information System (INIS)

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references

  14. Development of modified medium for the enhancement in antifungal activity of P. steckii (MF1 mangrove fungi against verticillium wilt pathogenic fungi of rose

    Directory of Open Access Journals (Sweden)

    Jyotasanmayee Sabat

    2009-08-01

    Full Text Available The antifungal activity of Penicillium steckii (MF1 against pathogenic fungi of rose causing verticillium wilt was evaluated under differential nutrient condition. A suitable and modified medium was obtained in which test fungus exhibited enhanced antifungal activity and produced larger inhibition zone against the verticillium fungus. The study carried out to modify the medium components at level of nitrogen, carbon source and their concentration on agar plates. Addition of amino acids, metals and plant growth hormones did not show positive effect but glycerol enhanced the antifungal activity very much.

  15. Control of Fusarium Wilt of Tomato Caused by Fusarium oxysporum F. Sp. Radicis-Lycopersici Using Mixture of Vegetable and Posidonia oceanica Compost

    OpenAIRE

    J. Downer; N. Jedidi; A. Hefiène; Fumio, M.; Bellila, A.; Brahmi, M.; Ben Rajeb, A.; Saidi, N.; Kouki, S.; H. Ouzari

    2012-01-01

    A compost of vegetable waste and Posidonia oceanica mixture (70 : 30% vol : vol) was tested in vitro and in vivo for its efficacy against Fusarium oxysporum f.sp radicis-lycopersici (Forl), the causal agent of Fusarium wilt of Tomato (Lycopersicon esculentum cv. chourouk).The incorporation of non-sterilized VPC in the culture medium showed potent antifungal activity against Forl and complete inhibition of mycelium growth was observed for all the tested compost rates (0.5, 1, 2, 4, 6, 8, 10, 1...

  16. Microbial Antagonism at the Root Level Is Involved in the Suppression of Fusarium Wilt by the Combination of Nonpathogenic Fusarium oxysporum Fo47 and Pseudomonas putida WCS358

    OpenAIRE

    Duijff, B.J. (Ben); Recorbet, Ghislaine; Bakker, P. A. H. M.; Loper, J E; Lemanceau, Philippe

    2001-01-01

    Two biological control agents, nonpathogenic Fusarium oxysporum Fo47 and Pseudomonas putida WCS358, were evaluated for suppression of Fusarium wilt of flax grown in nutrient solution and for suppression of the population density and metabolic activity of the causal organism F. oxysporum f. sp. lini strain Foln3GUS on root surfaces. Due to the presence of an introduced gusA reporter gene construct in Foln3GUS, the pathogen expressed b-glucuronidase activity that was related to its carbon metab...

  17. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  18. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte; Kruse, Torben; Nordström, Kurt

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  19. Bacterial terpene cyclases.

    Science.gov (United States)

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references. PMID:26563452

  20. Phenylacetic Acid Is ISR Determinant Produced by Bacillus fortis IAGS162, Which Involves Extensive Re-modulation in Metabolomics of Tomato to Protect against Fusarium Wilt

    Science.gov (United States)

    Akram, Waheed; Anjum, Tehmina; Ali, Basharat

    2016-01-01

    Bacillus fortis IAGS162 has been previously shown to induce systemic resistance in tomato plants against Fusarium wilt disease. In the first phase of current study, the ISR determinant was isolated from extracellular metabolites of this bacterium. ISR bioassays combined with solvent extraction, column chromatography and GC/MS analysis proved that phenylacetic acid (PAA) was the potential ISR determinant that significantly ameliorated Fusarium wilt disease of tomato at concentrations of 0.1 and 1 mM. In the second phase, the biochemical basis of the induced systemic resistance (ISR) under influence of PAA was elucidated by performing non-targeted whole metabolomics through GC/MS analysis. Tomato plants were treated with PAA and fungal pathogen in various combinations. Exposure to PAA and subsequent pathogen challenge extensively re-modulated tomato metabolic networks along with defense related pathways. In addition, various phenylpropanoid precursors were significantly up-regulated in treatments receiving PAA. This work suggests that ISR elicitor released from B. fortis IAGS162 contributes to resistance against fungal pathogens through dynamic reprogramming of plant pathways that are functionally correlated with defense responses. PMID:27148321

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Plant growth-promoting rhizobacteria strain Bacillus amyloliquefaciens NJN-6-enriched bio-organic fertilizer suppressed Fusarium wilt and promoted the growth of banana plants.

    Science.gov (United States)

    Yuan, Jun; Ruan, Yunze; Wang, Beibei; Zhang, Jian; Waseem, Raza; Huang, Qiwei; Shen, Qirong

    2013-04-24

    Bacillus amyloliquefaciens strain NJN-6 is an important plant growth-promoting rhizobacteria (PGPR) which can produce secondary metabolites antagonistic to several soil-borne pathogens. In this study, the ability of a bio-organic fertilizer (BIO) containing NJN-6 strain to promote the growth and suppress Fusarium wilt of banana plants was evaluated in a pot experiment. The results showed that the application of BIO significantly decreased the incidence of Fusarium wilt and promoted the growth of banana plants compared to that for the organic fertilizer (OF). To determine the beneficial mechanism of the strain, the colonization of NJN-6 strain on banana roots was evaluated using scanning electron microscopy (SEM). The plant growth-promoting hormones indole-3-acetic acid (IAA) and gibberellin A3 (GA3), along with antifungal lipopeptides iturin A, were detected when the NJN-6 strain was incubated in both Landy medium with additional l-tryptophan and in root exudates of banana plants. In addition, some antifungal volatile organic compounds and iturin A were also detected in BIO. In summary, strain NJN-6 could colonize the roots of banana plants after the application of BIO and produced active compounds which were beneficial for the growth of banana plants. PMID:23541032

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Effect of chipping on emergence of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae) and recovery of the laurel wilt pathogen from infested wood chips.

    Science.gov (United States)

    Spence, D J; Smith, J A; Ploetz, R; Hulcr, J; Stelinski, L L

    2013-10-01

    Significant mortality ofredbay trees (Persea borbonia (L.) Spreng.) in the southeastern United States has been caused by Raffaelea lauricola, T.C. Harr., Fraedrich, & Aghayeva (Harrington et al. 2008), a fungal symbiont of the exotic redbay ambrosia beetle, Xyleborus glabratus, Eichhoff (Fraedrich et al. 2008). This pathogen causes laurel wilt, which is an irreversible disease that can kill mature trees within a few weeks in summer. R. lauricola has been shown to be lethal to most native species of Lauraceae and cultivated avocado (Persea americana Mill.) in the southeastern United States. In this study, we examined the survival of X. glabratus and R. lauricola in wood chips made from infested trees by using a standard tree chipper over a 10-wk period. After 2 wk, 14 X. glabratus were recovered from wood chips, whereas 339 X. glabratus emerged from nonchipped bolts. R. lauricola was not found 2 d postchipping from wood chips, indicating that the pathogen is not likely to survive for long inside wood chips. In contrast, R. lauricola persisted in dead, standing redbay trees for 14 mo. With large volumes of wood, the potential for infested logs to be moved between states or across U.S. borders is significant. Results demonstrated that chipping wood from laurel wilt-killed trees can significantly reduce the number of X. glabratus and limit the persistence of R. lauricola, which is important for sanitation strategies aimed at limiting the spread of this disease. PMID:24224251

  5. A Review of Research Progress on Fusarium Wilt in Cucurbitaceae%瓜类枯萎病研究进展(综述)

    Institute of Scientific and Technical Information of China (English)

    乔燕春; 林锦英; 谢伟平; 郑岩松; 李莲芳; 谢丽芳

    2013-01-01

    Fusarium wilt in Cucurbitaceae is a soil-borne disease caused by Fusairum oxysporum. It can be observed in the cucurbit production regions around the world. It is now an important disease that could reduce quality and production of cucumber and melon since 1955, when it was first reported in China. In this paper, a review for Fusarium wilt in Cucurbitaceae was made from control methods, the pathogenic form, molecular research, respectively, and the future research was also prospected.%瓜类枯萎病是由尖孢镰刀菌Fusarium oxysporum侵染引起,在全球大部分瓜类产区均有发生。该病已成为影响我国瓜类品质和产量的重要病害。本文从瓜类作物枯萎病的防治方法、致病机理和分子生物学研究等方面综述其研究现状,并对今后的研究方向进行展望。

  6. Efeito do emurchecimento e do inoculante bacteriano sobre a qualidade da silagem de capim Tanzânia e o desempenho de novilhas = Effect of wilting and inoculant on Tanzania grass silage quality and heifers performance

    Directory of Open Access Journals (Sweden)

    Solidete de Fátima Paziani

    2006-10-01

    Full Text Available O objetivo desse trabalho foi avaliar o efeito do tamanho de partícula, do teor de MS e do uso de inoculante bacteriano sobre as propriedades físicas e perdas por deterioração da silagem de capim Tanzânia. Também foram avaliados a ingestão de MS (IMS, o ganho de peso vivo (GPV e a conversão alimentar (CA de novilhas alimentadascom rações completas contendo essa silagem. A redução no tamanho da partícula não aumentou as densidades de matéria seca (DMS e de massa verde (DMV, não reduziu a porosidade e nem as perdas durante a ensilagem. O emurchecimento não reduziu a DMS devido ao maior teor de MS, ocasionando maiores perdas. Não houve efeito dos tratamentos sobre a IMS (2,36% PV, o GPV (1,03 kg animal-1 dia-1 e a CA (7,91 kg MS kg-1 GPV. Os procedimentos adotados na ensilagem de capim Tanzânia não foram eficientes em evitar perdas e não provocaram melhoria no desempenho dos animais. The objective was to study the e ffect of particle size, dry mattercontent and the addition of bacterial inoculant to the ensiling of Tanzania grass ( Panicum maximum, Jacq. cv. Tanzânia on the physical characteristics and losses occurred during silo unloading. Dry matter intake, live we ight gain and feed conversion of beef heifers fed TMRcontaining grass silage were measured. The small particle size in the forage did not increase either wet or DM silages bulk densities, did not reduce the porosity and did not change the unloading losses. The forage wilting was not enough to reduce the DM density due to thecompensatory effect established by the higher DM content, which presented the highest losses. No significant differences were observed for treatments on animal DM intake (2.4%BW, body weight gain (1.03 kg animal-1 day-1 and feed conversion (7.91 kg MS kg-1BWG. Treatments in the ensiling of Tanzania grass did not prevent unloading losses and did not improve animal performance.

  7. Bacterial contamination of enteral diets.

    OpenAIRE

    de Leeuw, I H; Vandewoude, M F

    1986-01-01

    Enteral feeding solutions can be contaminated by bacterial micro-organisms already present in the ingredients, or introduced during preparation or transport, or in the hospital ward. During jejunostomy feeding without pump or filter, ascending bacterial invasion of the feeding bag is possible. In patients with lowered immune response contaminated feedings can cause serious septic clinical problems. The progressive loss of the nutritional value of the enteral feeding solution by bacterial cont...

  8. Transport powered by bacterial turbulence

    OpenAIRE

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-01-01

    We demonstrate that collective turbulent-like motion in a bacterial bath can power and steer directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedge-like "bulldozer" draws energy from a bacterial bath of varied density. We obtain that a maximal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp regi...

  9. Detection of Verticillium wilt of olive trees and downy mildew of opium poppy using hyperspectral and thermal UAV imagery

    Science.gov (United States)

    Calderón Madrid, Rocío; Navas Cortés, Juan Antonio; Montes Borrego, Miguel; Landa del Castillo, Blanca Beatriz; Lucena León, Carlos; Jesús Zarco Tejada, Pablo

    2014-05-01

    The present study explored the use of high-resolution thermal, multispectral and hyperspectral imagery as indicators of the infections caused by Verticillium wilt (VW) in olive trees and downy mildew (DM) in opium poppy fields. VW, caused by the soil-borne fungus Verticillium dahliae, and DM, caused by the biotrophic obligate oomycete Peronospora arborescens, are the most economically limiting diseases of olive trees and opium poppy, respectively, worldwide. V. dahliae infects the plant by the roots and colonizes its vascular system, blocking water flow and eventually inducing water stress. P. arborescens colonizes the mesophyll, appearing the first symptoms as small chlorotic leaf lesions, which can evolve to curled and thickened tissues and systemic infections that become deformed and necrotic as the disease develops. The work conducted to detect VW and DM infection consisted on the acquisition of time series of airborne thermal, multispectral and hyperspectral imagery using 2-m and 5-m wingspan electric Unmanned Aerial Vehicles (UAVs) in spring and summer of three consecutive years (2009 to 2011) for VW detection and on three dates in spring of 2009 for DM detection. Two 7-ha commercial olive orchards naturally infected with V. dahliae and two opium poppy field plots artificially infected by P. arborescens were flown. Concurrently to the airborne campaigns, olive orchards and opium poppy fields were assessed "in situ" to assess actual VW severity and DM incidence. Furthermore, field measurements were conducted at leaf and crown level. The field results related to VW detection showed a significant increase in crown temperature (Tc) minus air temperature (Ta) and a decrease in leaf stomatal conductance (G) as VW severity increased. This reduction in G was associated with a significant increase in the Photochemical Reflectance Index (PRI570) and a decrease in chlorophyll fluorescence. DM asymptomatic leaves showed significantly higher NDVI and lower green/red index

  10. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  11. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M;

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p <0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p <0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin...

  12. [Endogenous bacterial endophthalmitis].

    Science.gov (United States)

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  13. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  14. [Small intestine bacterial overgrowth].

    Science.gov (United States)

    Leung Ki, E L; Roduit, J; Delarive, J; Guyot, J; Michetti, P; Dorta, G

    2010-01-27

    Small intestine bacterial overgrowth (SIBO) is a condition characterised by nutrient malabsorption and excessive bacteria in the small intestine. It typically presents with diarrhea, flatulence and a syndrome of malabsorption (steatorrhea, macrocytic anemia). However, it may be asymptomatic in the eldery. A high index of suspicion is necessary in order to differentiate SIBO from other similar presenting disorders such as coeliac disease, lactose intolerance or the irritable bowel syndrome. A search for predisposing factor is thus necessary. These factors may be anatomical (stenosis, blind loop), or functional (intestinal hypomotility, achlorydria). The hydrogen breath test is the most frequently used diagnostic test although it lacks standardisation. The treatment of SIBO consists of eliminating predisposing factors and broad-spectrum antibiotic therapy. PMID:20214190

  15. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the...... benefits and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial...

  16. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  17. First identification on pathogen of papaya wilt disease in China%中国番木瓜枯萎病病原菌的首次鉴定

    Institute of Scientific and Technical Information of China (English)

    冯岩; 陈健; 罗金棠; 夏恭澍; 杜洪忠

    2011-01-01

    The pathogens of papaya wilt disease were identified on the basis of pathogenicity testing, as well as morphological characters and molecular identification. Isolates of possible pathogenic fungi were isolated from stems of infected papaya plants. Bases on the pathogenicity experiment, the results showed that the isolate was the pathogen of papaya wilt disease. The morphological identification showed that the isolate was consistent with Fu-sarium solani. By using of conservation and variability of the internal transcribed spacer (ITS) of fungi ribosome DNA, the isolate was amplified by PCR with universal primers of ITS1 and ITS4 and then sequenced. The sequence from the above isolate was compared with ten sequences published in Genbank database and phylogenitic trees were constructed based on ITS sequences data. The results showed that the tested isolate, GU134886^ GQ451337,EU625405,EF534183 and GQ376115 were clustered into the same clade and all of them were Fusarium solani. The molecular identification shared the same results with morphology identification. This is the first report that Fusarium solani is the pathogen of papaya wilt disease in China.%从发病的番木瓜茎基部组织分离培养得到纯分离物,采用形态学和分子生物学方法进行分离物鉴定.经过致病性测定证实,分离物确定为番木瓜枯萎病的病原菌;通过形态学观察表明,与茄腐镰刀菌(Fusarium solani)形态一致.根据真菌的核糖体DNA(rDNA)内转录间隔区(ITS)的保守性和变异性,采用通用引物ITS1和ITS4进行PCR扩增,然后将PCR产物纯化后直接测序,对测试菌株与10株来自GenBank中的菌株ITS序列进行聚类分析,结果表明,测试菌株与GenBank上注册的茄腐镰刀菌GU134886、GQ451337、EU625405、EF534183和GQ376115聚在同一分枝上,分子鉴定结果与形态学观察结果一致,此为国内首次报道.

  18. FRACIONAMENTO DE PROTEÍNAS DE SILAGEM DE CAPIM-ELEFANTE EMURCHECIDO OU COM FARELO DE CACAU PROTEIN FRACTIONING OF SILAGE OF ELEPHANTGRASS WILTED OR WITH COCOA MEAL

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2008-10-01

    Full Text Available

    Desenvolveu-se o experimento para determinar as frações que compõem as proteínas da silagem de capim-elefante (Pennisetum purpureum Schum. cv. Camaroon submetido ao emurchecimento ou à adição de diferentes níveis de farelo de cacau. O capim-elefante utilizado foi colhido aos 50 dias de rebrota após o corte de uniformização e submetido aos seguintes tratamentos: capim-elefante emurchecido ao sol por oito horas, e capim-elefante sem emurchecimento com níveis de 0 %, 7 %, 14%, 21 % e 28 % de farelo de cacau (FC (% da matéria natural. Acondicionou-se o material em silos de PVC com capacidade para 5,3 litros, que foram abertos após 45 dias. Para todas as frações de proteínas estimadas, o tratamento emurchecido apresentou valores semelhantes (P>0,05 ao do tratamento sem emurchecimento. As frações protéicas foram influenciadas pelas adições de FC, verificando-se redução dos teores das frações A e B1+B2 e aumentos das frações B3 e C, para os níveis crescentes de FC.

    PALAVRAS-CHAVES: Conservação de forragens, forrageira, Pennisetum purpureum Schum. cv. Cameroon, subproduto, Theobroma cacao L.

    The experiment was conducted to determine the fractions that compose the protein of silage on the submitted elephant grass forage to wilting under the sun light for eight hours. Other treatments involved the same elephant grass without exposing to sun light but with addition of 0, 7, 14, 21, and 28% of cocoa meal (CM at the ensilage processing. The PVC silos used in the experiment were 5.3 liters in capacity, and were opened in 45 days. To all protein-estimated fractions, the wilted treatment showed similar values (P>.05 to the treatment without wilting. The protein fractions were influenced by CM addictions, verifying reduction in contents of A and B1+B2 fractions and increase in B3 and C fractions, with CM increasing levels

  19. 晾晒和添加剂对菊苣青贮的影响%Effects of Wilting and Additives on Chicory Silage

    Institute of Scientific and Technical Information of China (English)

    张晓余; 玉柱; 张颖; 许庆方; 朱战波; 马涛

    2015-01-01

    为研究含水量和添加剂对菊苣(Cichorium intybus L)青贮的影响,以开花期菊苣鲜样和晾晒样为原料,分别添加甲酸(6mL/kg)或蔗糖(2%)处理,袋装并密封青贮360d后取样分析。结果表明,经晾晒后制作的菊苣青贮饲料的pH较高,乙酸和氨态氮含量极显著下降(P<0.01);添加甲酸或蔗糖均能够极显著降低菊苣青贮饲料的pH和氨态氮含量(P<0.01),极显著提高乳酸含量(P<0.01);青贮后硝酸盐含量下降。添加剂可以改善菊苣青贮饲料的发酵品质,菊苣经晾晒后再使用添加剂进行青贮效果更好。%Effects of additives and moisture contents on chicory silage were studied. Fresh and wilted chicory in the lfowering stage were placed in sealed vacum plastic bags with formic acid (6mL/kg) or sucrose (2%) and ensiled for 360 days. Results showed that wilting treatment increased pH, and decreased lactic acid and ammonia nitrogen contents significantly(P<0.01). Either formic acid or sucrose decreased pH, acetic acid and ammonia nitrogen contents and increased lactic acid contents of chicory silage (P<0.01). The nitrate content was reduced after ensilaged. Generally, the silage fermentation quality of chicory can be improved by adding either formic acid or sucrose, especially when the material was initially wilted.

  20. AB-QTL analysis reveals new alleles associated to proline accumulation and leaf wilting under drought stress conditions in barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Sayed Mohammed A

    2012-07-01

    Full Text Available Abstract Background Land plants have evolved several measures to maintain their life against abiotic stresses. The accumulation of proline is the most generalized response of plants under drought, heat or salt stress conditions. It is known as an osmoprotectant which also acts as an instant source of energy during drought recovery process. But, both its role and genetic inheritance are poorly understood in agriculture crops. In the present work, advanced backcross quantitative trait locus (AB-QTL analysis was performed to elucidate genetic mechanisms controlling proline accumulation and leaf wilting in barley under drought stress conditions. Results The analysis revealed eight QTL associated to proline content (PC and leaf wilting (WS. QTL for PC were localized on chromosome 3H, 4H, 5H and 6H. The strongest QTL effect QPC.S42.5H was detected on chromosome 5H where drought inducible exotic allele was associated to increase PC by 54%. QTL effects QPC.S42.3H, QPC.S42.4H and QPC.S42.6H were responsible to heighten PC due to the preeminence of elite alleles over the exotic alleles which ranged from 26% to 43%. For WS, QTL have been localized on chromosome 1H, 2H, 3H and 4H. Among these, QWS.S42.1H and QWS.S42.4H were associated to decrease in WS due to the introgression of exotic alleles. In addition, two digenic epistatic interaction effects were detected for WS where the additive effect of exotic alleles imparted a favorable increase in the trait value. Conclusions The present data represents a first report on whole-genome mapping of proline accumulation and leaf wilting in barley. The detected QTL are linked to new alleles from both cultivated and wild accessions which bring out an initial insight on the genetic inheritance of PC and WS. These QTL alleles are fixed in the isogenic background of Scarlett, which will allow for positional cloning of underlying genes and to develop drought resilient barley cultivars.

  1. Changes and recovery of soil bacterial communities influenced by biological soil disinfestation as compared with chloropicrin-treatment.

    Science.gov (United States)

    Mowlick, Subrata; Inoue, Takashi; Takehara, Toshiaki; Kaku, Nobuo; Ueki, Katsuji; Ueki, Atsuko

    2013-01-01

    Soil bacterial composition, as influenced by biological soil disinfestation (BSD) associated with biomass incorporation was investigated to observe the effects of the treatment on the changes and recovery of the microbial community in a commercial greenhouse setting. Chloropicrin (CP) was also used for soil disinfestation to compare with the effects of BSD. The fusarium wilt disease incidence of spinach cultivated in the BSD- and CP-treated plots was reduced as compared with that in the untreated control plots, showing effectiveness of both methods to suppress the disease. The clone library analyses based on 16S rRNA gene sequences showed that members of the Firmicutes became dominant in the soil bacterial community after the BSD-treatment. Clone groups related to the species in the class Clostridia, such as Clostridium saccharobutylicum, Clostridium tetanomorphum, Clostridium cylindrosporum, Oxobacter pfennigii, etc., as well as Bacillus niacini in the class Bacilli were recognized as the most dominant members in the community. For the CP-treated soil, clones affiliated with the Bacilli related to acid-tolerant or thermophilic bacteria such as Tuberibacillus calidus, Sporolactobacillus laevolacticus, Pullulanibacillus naganoensis, Alicyclobacillus pomorum, etc. were detected as the major groups. The clone library analysis for the soil samples collected after spinach cultivation revealed that most of bacterial groups present in the original soil belonging to the phyla Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Planctomycetes, TM7, etc. were recovered in the BSD-treated soil. For the CP-treated soil, the recovery of the bacterial groups belonging to the above phyla was also noted, but some major clone groups recognized in the original soil did not recover fully. PMID:23958081

  2. Molecular and biological characterization of highly infectious transcripts from full-length cDNA clones of broad bean wilt virus 1.

    Science.gov (United States)

    Ferriol, Inmaculada; Ambrós, Silvia; da Silva, Dorivaldo M; Falk, Bryce W; Rubio, Luis

    2016-06-01

    Broad bean wilt virus 1 (BBWV-1), genus Fabavirus, has a genome composed of two single-stranded positive-sense RNAs of ∼5.8 (RNA1) and 3.4kb (RNA2). Full-length cDNA clones of both genomic RNAs (pBenR1 and pBenR2) from BBWV-1 isolate Ben were constructed under the control of the T7 promoter. In vitro derived capped transcripts were infectious in Nicotiana benthamiana, Chenopodium quinoa and Vicia faba plants. The biological activity of viral transcripts was not affected by extra bases at the 5'-terminus introduced during in vitro transcription. Virions derived from the infectious cDNA clones displayed similar viral infectivity and accumulation, as well as symptom induction as the wild-type BBWV-1 isolate. PMID:26951858

  3. Studies on the management of root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex of green gram, Vigna radiata cv ML-1108

    Institute of Scientific and Technical Information of China (English)

    HASEEB Akhtar; SHARMA Anita; SHUKLA Prabhat Kumar

    2005-01-01

    Studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil,bavistin at 1 mg a.i./kg soil, neem (Azadirachta indica) seed powder at 50 mg/kg soil, green mould (Trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (Pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex on green gram, Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared to untreated inoculated plants. Analysis of data showed that carbofuran and A. indica seed powder increased plant growth and yield significantly more in comparison to bavistin and P.fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus, A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.

  4. EFFICACY OF RHIZOBACTERIA AND HUMIC ACID FOR CONTROLLING FUSARIUM WILT DISEASE AND IMPROVEMENT OF PLANT GROWTH, QUANTITATIVE AND QUALITATIVE PARAMETERS IN TOMATO

    Directory of Open Access Journals (Sweden)

    Magd El-Morsy A. El-Morsy

    2012-12-01

    Full Text Available The effect of tomato seedling treated with plant growth promoting rhizobacteria (PGPR strains viz. Azotobacter sp. (AZM1,Bacillus cereus (BCM8, B. megaterium (BMM5 individually or combined with humic acid were evaluated for controlling wilt disease caused by Fusarium oxysporum f. sp. lycopersici, plant growth, fruit quantitative and qualitative (cv. Super Strain-B during 2010-2011 and 2011-2012 growing seasons. Under greenhouse conditions, all treatments significantly reduced area under disease progress curve (AUDPC and increased plant height, fresh and dry weights of survival plants growing in pots infested with the causal pathogen compared with control. Combination treatments of humic acid with PGPR reduced significantly wilt incidence and increased plant height, fresh and dry weights of tomato plants comparing with the application of each of them alone. Under laboratory conditions, all PGPR strains and humic acid able to inhibited leaner growth of the causal pathogen with different degrees and PGPR strains were more active than humic acid in this respect.  Under field conditions, all PGPR stains individually or combined with humic acid significantly reduced AUDPC and improved plant growth (plant height, number of branches plant -1 quantitative (number of fruits plant  -1, fruit weight plant -1, fruit weight, fruit yield fed.  -1, Number of fruit Kg  -1 and qualitative (degree of   fruit’s color, fruit diameters, firmness, fruit height, total soluble solids parameters of tomato fruits compared with untreated plants (control in both growing seasons. Combination treatments of humic acid with PGPR strains increase the effectiveness of them in this respect  more than   used alone.

  5. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  6. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  7. The rare bacterial biosphere.

    Science.gov (United States)

    Pedrós-Alió, Carlos

    2012-01-01

    All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether "everything is everywhere." Third, it will require hypothesizing and testing the ecological mechanisms that allow subsistence of many species in low numbers. And fourth, it will open an avenue of research into the immense reserve of genes with potential applications hidden in the rare biosphere. PMID:22457983

  8. Transport Powered by Bacterial Turbulence

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-04-01

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations.

  9. Transport powered by bacterial turbulence.

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S

    2014-04-18

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations. PMID:24785075

  10. 苜蓿混合凋萎青贮技术对青贮品质的影响%Effects of Mixed Wilting Silage Technology on Alfalfa Silage Quality

    Institute of Scientific and Technical Information of China (English)

    贾纳提; 刘梦; 李莉; 董志国; 麦丽亚·伊尔斯比克

    2012-01-01

    对苜蓿+无芒雀麦+披碱草和苜蓿+无芒雀麦+冰草的混播草地牧草采用凋萎青贮技术进行混合青贮,以单独凋萎青贮新疆大叶苜蓿设为对照,分析各处理青贮材料的pH值、CP、NDF、ADF、乙酸、乳酸、丙酸和氨态氮的变化,比较其混合青贮技术对青贮品质的影响。试验结果表明,苜蓿混合凋萎青贮无论从青贮感官指标,还是从青贮料的营养成分及有机酸含量,其表现比单独凋萎青贮效果好。在混合凋萎青贮处理的两个组合中,苜蓿+无芒雀麦+冰草混合青贮效果最理想。%The mixed wilting silage technology was used on Xinjiang big leaf alfalfa-Medicago sativa L. + Bromus inermis Leyss + Agropyron cristatum and Xinjiang big leaf alfalfa-Medicago sativa L. + Bromus inermis Leyss + Elymus dahuricus Turcz, and set single- wilting silage as control. PH value,CP, NDF, ADF, Butyric acid, Acetic acid, Propionic acid and NH3-N content in each treatment changes were analysed to compare the effects of mixed wilting silage technology on alfalfa silage quality .The results showed that alfalfa mixed wilting silage ,whether from the sensory index of silage, or from the nutrients and organic acid contents of silage to consider ,the effect was better than single-wilting silage. In the two combinations of mixed wilting silage treatment, the treatment Xinjiang big leaf alfalfa- Medicago sativa L. + Bromus inermis Leyss + Agropyron cristatum silage effect was better..

  11. OxyR and SoxR modulate the inducible oxidative stress response and are implicated during different stages of infection for the bacterial phytopathogen Pantoea stewartii subsp. stewartii.

    Science.gov (United States)

    Burbank, Lindsey; Roper, M Caroline

    2014-05-01

    Reactive oxygen species (ROS) from a variety of sources are often encountered by invading plant pathogens during the infection process. Pantoea stewartii subsp. stewartii, the etiological agent of Stewart's wilt, is a serious bacterial pathogen of sweet corn that colonizes both the apoplast and xylem tissues in which ROS are produced. The P. stewartii genome predicts the presence of two redox-sensing transcriptional regulators, OxyR and SoxR, which both activate gene expression in response to oxidative stress. ROS exposure in the form of hydrogen peroxide and the superoxide-generating compound paraquat initiates an induced stress response through OxyR and SoxR that includes activation of the ROS-detoxifying enzymes alkyl hydroperoxide reductase and superoxide dismutase. P. stewartii ΔsoxR was more sensitive to paraquat and was compromised in the ability to form water-soaked lesions, while ΔoxyR was more sensitive to hydrogen peroxide treatment and was deficient in exopolysaccharide production and the elicitation of wilting symptoms. This demonstrates that both SoxR and OxyR play an important role in virulence in the different niches that P. stewartii colonize during the infection process. PMID:24450773

  12. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  13. Bacterial Communities: Interactions to Scale

    Science.gov (United States)

    Stubbendieck, Reed M.; Vargas-Bautista, Carol; Straight, Paul D.

    2016-01-01

    In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities. PMID:27551280

  14. The Bacterial Microflora of Fish

    OpenAIRE

    Austin, B.

    2002-01-01

    The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen) of healthy fish may contain bacteria, but there is debate on whether or not muscle is actually sterile. The numbers and taxonomic composition of the bacterial populations often reflect those of the surrounding water. The role of the bacteria includes the ability to degrade complex m...

  15. Bacterial cellulose/boehmite composites

    Energy Technology Data Exchange (ETDEWEB)

    Salvi, Denise T.B. de; Barud, Hernane S.; Messaddeq, Younes; Ribeiro, Sidney J.L. [Universidade Estadual Paulista Julio de Mesquita Filho. UNESP. Instituto de Quimica de Araraquara, SP (Brazil); Caiut, Jose Mauricio A. [Universidade de Sao Paulo. Departamento de Quimica - FFCLRP/USP, Ribeirao Preto, SP (Brazil)

    2011-07-01

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  16. Bacterial Culture of Neonatal Sepsis

    OpenAIRE

    AH Movahedian; R Moniri; Z Mosayebi

    2006-01-01

    Neonatal bacterial sepsis is one of the major cause of morbidity and mortality in neonates. This retrospective study was performed to determine the incidence of bacterial sepsis with focus on Gram negative organisms in neonates admitted at Beheshti Hospital in Kashan, during a 3-yr period, from September 2002 to September 2005. Blood culture was performed on all neonates with risk factors or signs of suggestive sepsis. Blood samples were cultured using brain heart infusion (BHI) broth accordi...

  17. Bacterial Alkaloids Prevent Amoebal Predation.

    Science.gov (United States)

    Klapper, Martin; Götze, Sebastian; Barnett, Robert; Willing, Karsten; Stallforth, Pierre

    2016-07-25

    Bacterial defense mechanisms have evolved to protect bacteria against predation by nematodes, predatory bacteria, or amoebae. We identified novel bacterial alkaloids (pyreudiones A-D) that protect the producer, Pseudomonas fluorescens HKI0770, against amoebal predation. Isolation, structure elucidation, total synthesis, and a proposed biosynthetic pathway for these structures are presented. The generation of P. fluorescens gene-deletion mutants unable to produce pyreudiones rendered the bacterium edible to a variety of soil-dwelling amoebae. PMID:27294402

  18. Mast cells in bacterial infections

    OpenAIRE

    Rönnberg, Elin

    2014-01-01

    Mast cells are implicated in immunity towards bacterial infection, but the molecular mechanisms by which mast cells contribute to the host response are only partially understood. Previous studies have examined how mast cells react to purified bacterial cell wall components, such as peptidoglycan and lipopolysaccharide. To investigate how mast cells react to live bacteria we co-cultured mast cells and the gram-positive bacteria Streptococcus equi (S. equi) and Staphylococcus aureus (S. aureus)...

  19. Studies of Experimental Bacterial Translocation

    OpenAIRE

    Stenbäck, Anders

    2005-01-01

    One of the main obstacles to maintaining patients with short bowel syndrome on parenteral nutrition, or successfully transplanting these patients with a small bowel graft, is the many severe infections that occur. Evidence is accumulating that translocating bacteria from the patient’s bowel causes a significant part of these infections. In this thesis bacterial translocation is studied in a Thiry-Vella loop of defunctionalised small bowel in the rat. Bacterial translocation to the mesenteric ...

  20. Bacterial translocation: impact of probiotics

    OpenAIRE

    Jeppsson, Bengt; Mangell, Peter; Adawi, Diya; Molin, Göran

    2004-01-01

    There is a considerable amount of data in humans showing that patients who cannot take in nutrients enterally have more organ failure in the intensive care unit, a less favourable prognosis, and a higher frequency of septicaemia, in particular involving bacterial species from the intestinal tract. However, there is little evidence that this is connected with translocation of bacterial species in humans. Animal data more uniformly imply the existence of such a connection. The main focus of thi...

  1. Electrical spiking in bacterial biofilms

    OpenAIRE

    Masi, Elisa; Ciszak, Marzena; Santopolo, Luisa; Frascella, Arcangela; Giovannetti, Luciana; Marchi, Emmanuela; Viti, Carlo; Mancuso, Stefano

    2015-01-01

    In nature, biofilms are the most common form of bacterial growth. In biofilms, bacteria display coordinated behaviour to perform specific functions. Here, we investigated electrical signalling as a possible driver in biofilm sociobiology. Using a multi-electrode array system that enables high spatio-temporal resolution, we studied the electrical activity in two biofilm-forming strains and one non-biofilm-forming strain. The action potential rates monitored during biofilm-forming bacterial gro...

  2. Bacterial sex in dental plaque

    OpenAIRE

    Olsen, Ingar; Tribble, Gena D; Fiehn, Nils-Erik; Wang, Bing-Yan

    2013-01-01

    Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it a...

  3. Bacterial contamination of radiopharmaceutical preparations

    International Nuclear Information System (INIS)

    Examinations of the microflora of the air, personnel hands' skin, and surface of the equipment were performed in the Centre for Nuclear research, Libya. It is stated that bacterial contamination was maximal in winter and minimal in summer. The authors believe that human factor is the crucial in bacterial contamination. The microflora detected at the surfaces of equipment contains increased levels of radioresistent forms of bacteria. 8 refs.; 3 tabs

  4. Bacterial cellulose/boehmite composites

    International Nuclear Information System (INIS)

    Composites based on bacterial cellulose membranes and boehmite were obtained. SEM results indicate that the bacterial cellulose (BC) membranes are totally covered by boehmite and obtained XRD patterns suggest structural changes due to this boehmite addition. Thermal stability is accessed through TG curves and is dependent on boehmite content. Transparency is high comparing to pure BC as can be seen through UV-vis absorption spectroscopy. (author)

  5. Meningitis bacteriana Bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Ana Teresa Alvarado Guevara

    2006-03-01

    causales son virales lo cual conlleva a las diferentes sub-clasificaciones. También en ciertos casos puede ser ocasionada por hongos, bacterias atípicas, micobacterias y parásitos.In Costa Rica the bacterial meningitis had turn into a high-priority subject in which to monitoring epidemiologist. It had been talked about in the last months, to dice an increase in the attention is published of this subject, due to this phenomenon it becomes necessary to make a revision of topic. Meningitis is an inflammation of leptomeninges and colonization of the subarachnoid cerebrospinal fluid (LCR due to different agents, which produces meningeal symptoms (ex. migraine, neck rigidity, and photophobia and pleocytosis in LCR. De pending on the variables to take into account is possible to group it in different classifications, taking into account the time of evolution are possible to be divided in acute or chronic, to first with few hours or days of beginning of the symptoms, whereas the chronicle also presents a silence course but of the disease of approximately 4 weeks of instauration. There is a difference according to its etiologic agent; they can be infectious and non-infectious. Examples of common non-infectious causes include medications (ex, nonsteroidal anti-inflammatory drugs, and antibiotics and carcinomatosis. A classification exists as well according to the causal agent. The acute bacterial meningitis remarks a bacterial origin of the syndrome, which characterizes by the by an acute onset of meningeal symptoms and neutrophilic pleocytosis. Each one of the bacteriological agents, parasitic or fungus finishes by characterizing the different presentations of the clinical features (ex, meningocóccica meningitis, Cryptococcus meningitis. Finally, there is also the aseptic meningitis, denominated in this form because it’s nonpyogenic cellular response caused by many types of agents. The patients show an acute beginning of symptoms, fever and lymphocytic pleocytosis. After

  6. 7 CFR 58.135 - Bacterial estimate.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Bacterial estimate. 58.135 Section 58.135 Agriculture... Milk § 58.135 Bacterial estimate. (a) Methods of Testing. Milk shall be tested for bacterial estimate... of Testing. A laboratory examination to determine the bacterial estimate shall be made on...

  7. Microfluidic Approaches to Bacterial Biofilm Formation

    OpenAIRE

    Hee-Deung Park; Junghyun Kim; Seok Chung

    2012-01-01

    Bacterial biofilms—aggregations of bacterial cells and extracellular polymeric substrates (EPS)—are an important subject of research in the fields of biology and medical science. Under aquatic conditions, bacterial cells form biofilms as a mechanism for improving survival and dispersion. In this review, we discuss bacterial biofilm development as a structurally and dynamically complex biological system and propose microfluidic approaches for the study of bacterial biofilms. Biofilms develop t...

  8. The human vaginal bacterial biota and bacterial vaginosis.

    Science.gov (United States)

    Srinivasan, Sujatha; Fredricks, David N

    2008-01-01

    The bacterial biota of the human vagina can have a profound impact on the health of women and their neonates. Changes in the vaginal microbiota have been associated with several adverse health outcomes including premature birth, pelvic inflammatory disease, and acquisition of HIV infection. Cultivation-independent molecular methods have provided new insights regarding bacterial diversity in this important niche, particularly in women with the common condition bacterial vaginosis (BV). PCR methods have shown that women with BV have complex communities of vaginal bacteria that include many fastidious species, particularly from the phyla Bacteroidetes and Actinobacteria. Healthy women are mostly colonized with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners, though a variety of other bacteria may be present. The microbiology of BV is heterogeneous. The presence of Gardnerella vaginalis and Atopobium vaginae coating the vaginal epithelium in some subjects with BV suggests that biofilms may contribute to this condition. PMID:19282975

  9. New Treatments for Bacterial Keratitis

    Directory of Open Access Journals (Sweden)

    Raymond L. M. Wong

    2012-01-01

    Full Text Available Purpose. To review the newer treatments for bacterial keratitis. Data Sources. PubMed literature search up to April 2012. Study Selection. Key words used for literature search: “infectious keratitis”, “microbial keratitis”, “infective keratitis”, “new treatments for infectious keratitis”, “fourth generation fluoroquinolones”, “moxifloxacin”, “gatifloxacin”, “collagen cross-linking”, and “photodynamic therapy”. Data Extraction. Over 2400 articles were retrieved. Large scale studies or publications at more recent dates were selected. Data Synthesis. Broad spectrum antibiotics have been the main stay of treatment for bacterial keratitis but with the emergence of bacterial resistance; there is a need for newer antimicrobial agents and treatment methods. Fourth-generation fluoroquinolones and corneal collagen cross-linking are amongst the new treatments. In vitro studies and prospective clinical trials have shown that fourth-generation fluoroquinolones are better than the older generation fluoroquinolones and are as potent as combined fortified antibiotics against common pathogens that cause bacterial keratitis. Collagen cross-linking was shown to improve healing of infectious corneal ulcer in treatment-resistant cases or as an adjunct to antibiotics treatment. Conclusion. Fourth-generation fluoroquinolones are good alternatives to standard treatment of bacterial keratitis using combined fortified topical antibiotics. Collagen cross-linking may be considered in treatment-resistant infectious keratitis or as an adjunct to antibiotics therapy.

  10. Interfering with Bacterial Quorum Sensing.

    Science.gov (United States)

    Reuter, Kerstin; Steinbach, Anke; Helms, Volkhard

    2016-01-01

    Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery. PMID:26819549

  11. Bacterial tactic responses.

    Science.gov (United States)

    Armitage, J P

    1999-01-01

    Many, if not most, bacterial species swim. The synthesis and operation of the flagellum, the most complex organelle of a bacterium, takes a significant percentage of cellular energy, particularly in the nutrient limited environments in which many motile species are found. It is obvious that motility accords cells a survival advantage over non-motile mutants under normal, poorly mixed conditions and is an important determinant in the development of many associations between bacteria and other organisms, whether as pathogens or symbionts and in colonization of niches and the development of biofilms. This survival advantage is the result of sensory control of swimming behaviour. Although too small to sense a gradient along the length of the cell, and unable to swim great distances because of buffetting by Brownian motion and the curvature resulting from a rotating flagellum, bacteria can bias their random swimming direction towards a more favourable environment. The favourable environment will vary from species to species and there is now evidence that in many species this can change depending on the current physiological growth state of the cell. In general, bacteria sense changes in a range of nutrients and toxins, compounds altering electron transport, acceptors or donors into the electron transport chain, pH, temperature and even the magnetic field of the Earth. The sensory signals are balanced, and may be balanced with other sensory pathways such as quorum sensing, to identify the optimum current environment. The central sensory pathway in this process is common to most bacteria and most effectors. The environmental change is sensed by a sensory protein. In most species examined this is a transmembrane protein, sensing the external environment, but there is increasing evidence for additional cytoplasmic receptors in many species. All receptors, whether sensing sugars, amino acids or oxygen, share a cytoplasmic signalling domain that controls the activity of a

  12. Induced Resistance in Tomato Plants against Verticillium Wilt by the Binuclear Nickel Coordination Complex of the Ligand 2,5-Bis(pyridin-2-yl)-1,3,4-thiadiazole.

    Science.gov (United States)

    Zine, Hanane; Rifai, Lalla Aicha; Faize, Mohamed; Bentiss, Fouad; Guesmi, Salaheddine; Laachir, Abdelhakim; Smaili, Amal; Makroum, Kacem; Sahibed-Dine, Abdelaziz; Koussa, Tayeb

    2016-04-01

    Verticillium wilt caused by Verticillium dahliae is a major limiting factor for tomato production. The objective of this study was to evaluate the effectiveness of ligand 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole (L) and its complex bis[μ-2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ(4)N(2),N(3):N(4),N(5)]bis[dihydrato-κO)nickel(II)] as activators of plant defenses in controlling Verticillium wilt. In the greenhouse, they protected tomato plants against V. dahliae when they were applied twice as foliar sprays at 100 μg mL(-1). A synergistic effect was observed between the ligand L and the transition metal Ni, with disease incidence reduced by 38% with L and 57% with Ni2L2. Verticillium wilt foliar symptoms and vascular browning index were reduced by 82% for L and 95% for Ni2L2. This protection ability was associated with the induction of an oxidative burst and the activation of the total phenolic content as well as potentiation of the activity of peroxidase and polyphenol oxidase. These results demonstrated that L and Ni2L2 can be considered as new activators of plant defense responses. PMID:26991972

  13. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten;

    2010-01-01

    Bacteria and Eukarya share essentially the same family of protein-serine/threonine kinases, also known as the Hanks-type kinases. However, when it comes to protein-tyrosine phosphorylation, bacteria seem to have gone their own way. Bacterial protein-tyrosine kinases (BY-kinases) are bacterial...... enzymes that are unique in exploiting the ATP/GTP-binding Walker motif to catalyze phosphorylation of protein tyrosine residues. Characterized for the first time only a decade ago, BY-kinases have now come to the fore. Important regulatory roles have been linked with these enzymes, via their involvement...... in exopolysaccharide production, virulence, DNA metabolism, stress response and other key functions of the bacterial cell. BY-kinases act through autophosphorylation (mainly in exopolysaccharide production) and phosphorylation of other proteins, which have in most cases been shown to be activated by...

  14. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  15. Phylogenetic organization of bacterial activity.

    Science.gov (United States)

    Morrissey, Ember M; Mau, Rebecca L; Schwartz, Egbert; Caporaso, J Gregory; Dijkstra, Paul; van Gestel, Natasja; Koch, Benjamin J; Liu, Cindy M; Hayer, Michaela; McHugh, Theresa A; Marks, Jane C; Price, Lance B; Hungate, Bruce A

    2016-09-01

    Phylogeny is an ecologically meaningful way to classify plants and animals, as closely related taxa frequently have similar ecological characteristics, functional traits and effects on ecosystem processes. For bacteria, however, phylogeny has been argued to be an unreliable indicator of an organism's ecology owing to evolutionary processes more common to microbes such as gene loss and lateral gene transfer, as well as convergent evolution. Here we use advanced stable isotope probing with (13)C and (18)O to show that evolutionary history has ecological significance for in situ bacterial activity. Phylogenetic organization in the activity of bacteria sets the stage for characterizing the functional attributes of bacterial taxonomic groups. Connecting identity with function in this way will allow scientists to begin building a mechanistic understanding of how bacterial community composition regulates critical ecosystem functions. PMID:26943624

  16. Abdominal radiation causes bacterial translocation

    International Nuclear Information System (INIS)

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa

  17. Biology and host associations of redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae), exotic vector of laurel wilt killing redbay trees in the southeastern United States.

    Science.gov (United States)

    Hanula, James L; Mayfield, Albert E; Fraedrich, Stephen W; Rabaglia, Robert J

    2008-08-01

    The redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), and its fungal symbiont, Raffaelea sp., are new introductions to the southeastern United States responsible for the wilt of mature redbay, Persea borbonia (L.) Spreng., trees. In 2006 and 2007, we investigated the seasonal flight activity of X. glabratus, its host associations, and population levels at eight locations in South Carolina and Georgia where infestations ranged from very recent to at least several years old. Adults were active throughout the year with peak activity in early September. Brood development seems to take 50-60 d. Wood infested with beetles and infected with the Raffaelea sp. was similar in attraction to uninfested redbay wood, whereas both were more attractive than a nonhost species. Sassafras, Sassafras albidium (Nutt.) Nees, another species of Lauraceae, was not attractive to X. glabratus and very few beetle entrance holes were found in sassafras wood compared with redbay. Conversely, avocado, Persea americana Mill., was as attractive to X. glabratus as swampbay, P. palustris (Raf.) Sarg., and both were more attractive than the nonhost red maple, Acer rubrum L. However, avocado had relatively few entrance holes in the wood. In 2007, we compared X. glabratus populations in areas where all mature redbay have died to areas where infestations were very active and more recent. Trap catches of X. glabratus and numbers of entrance holes in trap bolts of redbay were correlated with the number of dead trees with leaves attached. Older infestations where mature host trees had been eliminated by the wilt had low numbers of beetles resulting in trap catches ranging from 0.04 to 0.12 beetles per trap per d compared with 4-7 beetles per trap per d in areas with numerous recently dead trees. Our results indicate beetle populations drop dramatically after suitable host material is gone and provide hope that management strategies can be developed to restore

  18. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.

    Science.gov (United States)

    Ulloa, M; Wang, C; Saha, S; Hutmacher, R B; Stelly, D M; Jenkins, J N; Burke, J; Roberts, P A

    2016-04-01

    Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease

  19. Bacterial contamination of blood components.

    Science.gov (United States)

    Seghatchian, J

    2001-10-01

    Despite considerable advances in the safety of blood components, transfusion associated bacterial infection (TABI) remains an unresolved problem. As yet there are no perfect preventative, screening and/or detection methodologies for eliminating contaminated units. Until a practical, rapid, cost-effective and logistically acceptable test becomes available, we should be satisfied with the choice of various limited solutions that at least partially improve the bacterial safety of blood components. It is also necessary to establish standardised guidelines and agreed upon systematic procedures for the recognition and reporting of the laboratory and clinical evaluation of adverse reactions in recipients of contaminated blood components. PMID:11761277

  20. Molecular Mechanisms Underlying Bacterial Persisters

    DEFF Research Database (Denmark)

    Maisonneuve, Etienne; Gerdes, Kenn

    2014-01-01

    All bacteria form persisters, cells that are multidrug tolerant and therefore able to survive antibiotic treatment. Due to the low frequencies of persisters in growing bacterial cultures and the complex underlying molecular mechanisms, the phenomenon has been challenging to study. However, recent...... technological advances in microfluidics and reporter genes have improved this scenario. Here, we summarize recent progress in the field, revealing the ubiquitous bacterial stress alarmone ppGpp as an emerging central regulator of multidrug tolerance and persistence, both in stochastically and environmentally...

  1. Cognition and Controlling Behavior of Banana Fusarium Wilt with Structural Equation Modeling%基于结构方程的香蕉枯萎病认知及防控技术行为分析

    Institute of Scientific and Technical Information of China (English)

    夏勇开; 刘殿国

    2015-01-01

    香蕉枯萎病是一种传染性极强的土传病害,对生产危害极大。从研究香蕉种植户对枯萎病的认知特征和防控技术行为入手,可以为科学防控枯萎病提供基础。本研究以海南、广东、广西、福建和云南等香蕉主产区的20个县(区)的133份调查资料为样本,采用结构方程模型进行研究,结果表明:认知程度直接影响香蕉枯萎病防控技术的扩散,防控成本、受教育程度、收入水平、技术培训经历和种植经验等均不同程度地影响种植户对枯萎病的防控行为;蕉园土壤酸碱度及有机质含量、抗逆品种的选择对枯萎病蔓延有一定的影响。引导和规范种植户修复土壤、重施有机肥、注重土壤酸碱度平衡等生产技术行为,可以抑制或减缓枯萎病的蔓延;拓展香蕉种植户对枯萎病防控技术的认知深度,以“技术的供给与需求相结合”为导向,加大扶持力度,建立起枯萎病统防统治等综合防控体系,可以达到抑制枯萎病的目的。%Banana fusarium wilt has great harmful to the agricultural production, which is a highly contagious soil-borne diseases. Therefore, the study on farmers' cognitive characteristics and control behavior of banana fusarium wilt, will provide foundation for scientific prevention and control of wilt disease. This paper takes 133 scattered rural households survey data as the sample which is collected from 20 counties (districts) in the major banana production area of Hainan, Guangdong, Guangxi, Fujian and Yunnan, and introduces structural equation model to analyze these collected questionnaires. One of results of this study shows that cognition degree of banana fusarium wilt among growers has a direct impact on the diffusion of this disease's prevention and control technology. Specially, these factors such as educational level, income standard, technical training and the experience in planting etc. all have effects

  2. Proteomics of foodborne bacterial pathogens

    Science.gov (United States)

    This chapter focuses on recent research on foodborne bacterial pathogens that use mass spectrometry-based proteomic techniques as well as protein microarrays. Mass spectrometry ionization techniques (e.g. electrospray ionization and matrix-assisted laser desorption/ionization), analyzers (e.g. ion ...

  3. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  4. Regulation of Bacterial Peptidoglycan Polymerization.

    Science.gov (United States)

    Arthur, Michel

    2016-07-01

    How bacterial cells control the activity of peptidoglycan polymerases has remained mysterious. Biochemical characterization of derivatives of penicillin-binding protein PBP1b that are functional in the absence of lipoprotein LpoB provides evidence for allosteric control of PBP1b glycosyltransferase activity via binding of LpoB to the PBP1b UBH1 domain. PMID:27236859

  5. How carotenoids protect bacterial photosynthesis.

    OpenAIRE

    Cogdell, R J; Howard, T. D.; Bittl, R.; Schlodder, E; Geisenheimer, I; Lubitz, W.

    2000-01-01

    The essential function of carotenoids in photosynthesis is to act as photoprotective agents, preventing chlorophylls and bacteriochlorophylls from sensitizing harmful photodestructive reactions in the presence of oxygen. Based upon recent structural studies on reaction centres and antenna complexes from purple photosynthetic bacteria, the detailed organization of the carotenoids is described. Then with specific reference to bacterial antenna complexes the details of the photoprotective role, ...

  6. Food irradiation and bacterial toxins

    International Nuclear Information System (INIS)

    The authors' findings indicate that irradiation confers no advantage over heat processing in respect of bacterial toxins (clostridium botulinum, neurotoxin A and staphylococcal enterotoxin A). It follows that irradiation at doses less than the ACINF recommended upper limit of 10 kGy could not be used to improve the ambient temperature shelf life on non-acid foods. (author)

  7. Biotechnological applications of bacterial cellulases

    Directory of Open Access Journals (Sweden)

    Esther Menendez

    2015-08-01

    Full Text Available Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, meanwhile exoglucanases cleave the remaining oligosaccharide chains, originating cellobiose, which is hydrolyzed by ß-glucanases. Bacterial cellulases (EC 3.2.1.4 are comprised in fourteen Glycosil Hydrolase families. Several advantages, such as higher growth rates and genetic versatility, emphasize the suitability and advantages of bacterial cellulases over other sources for this group of enzymes. This review summarizes the main known cellulolytic bacteria and the best strategies to optimize their cellulase production, focusing on endoglucanases, as well as it reviews the main biotechnological applications of bacterial cellulases in several industries, medicine and agriculture.

  8. BACTERIAL INHIBITORS IN LAKE WATER

    Science.gov (United States)

    The populations of six bacterial genera fell rapidly after their addition to sterile lake water but not after their addition to buffer. The decline in numbers of two species that were studied further, Klebsiella pneumoniae and Micrococcus flavus, occurred even when the buffer was...

  9. Bacterial kidney disease (Renibacterium salmoninarum)

    Science.gov (United States)

    Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a prevalent disease of salmonid fish that impacts sustainable production for consumption and species conservation efforts. The disease is chronic in nature and mortality most often occurs in juvenile salmonids and prespawning a...

  10. The inheritance of resistance to Verticillium wilt caused by race 1 isolates of Verticillium dahliae in the lettuce cultivar La Brillante.

    Science.gov (United States)

    Hayes, Ryan J; McHale, Leah K; Vallad, Gary E; Truco, Maria Jose; Michelmore, Richard W; Klosterman, Steve J; Maruthachalam, Karunakaran; Subbarao, Krishna V

    2011-08-01

    Verticillium wilt of lettuce caused by Verticillium dahliae can cause severe economic damage to lettuce producers. Complete resistance to race 1 isolates is available in Lactuca sativa cultivar (cv.) La Brillante and understanding the genetic basis of this resistance will aid development of new resistant cultivars. F(1) and F(2) families from crosses between La Brillante and three iceberg cultivars as well as a recombinant inbred line population derived from L. sativa cv. Salinas 88 × La Brillante were evaluated for disease incidence and disease severity in replicated greenhouse and field experiments. One hundred and six molecular markers were used to generate a genetic map from Salinas 88 × La Brillante and for detection of quantitative trait loci. Segregation was consistent with a single dominant gene of major effect which we are naming Verticillium resistance 1 (Vr1). The gene described large portions of the phenotypic variance (R(2) = 0.49-0.68) and was mapped to linkage group 9 coincident with an expressed sequence tag marker (QGD8I16.yg.ab1) that has sequence similarity with the Ve gene that confers resistance to V. dahliae race 1 in tomato. The simple inheritance of resistance indicates that breeding procedures designed for single genes will be applicable for developing resistant cultivars. QGD8I16.yg.ab1 is a good candidate for functional analysis and development of markers suitable for marker-assisted selection. PMID:21567237

  11. Phylogenetic analysis of Tomato spotted wilt virus (TSWV) NSs protein demonstrates the isolated emergence of resistance-breaking strains in pepper.

    Science.gov (United States)

    Almási, Asztéria; Csilléry, Gábor; Csömör, Zsófia; Nemes, Katalin; Palkovics, László; Salánki, Katalin; Tóbiás, István

    2015-02-01

    Resurgence of Tomato spotted wilt virus (TSWV) worldwide as well as in Hungary causing heavy economic losses directed the attention to the factors contributing to the outbreak of this serious epidemics. The introgression of Tsw resistance gene into various pepper cultivars seemed to solve TSWV control, but widely used resistant pepper cultivars bearing the same, unique resistance locus evoked the rapid emergence of resistance-breaking (RB) TSWV strains. In Hungary, the sporadic appearance of RB strains in pepper-producing region was first observed in 2010-2011, but in 2012 it was detected frequently. Previously, the non-structural protein (NSs) encoded by small RNA (S RNA) of TSWV was verified as the avirulence factor for Tsw resistance, therefore we analyzed the S RNA of the Hungarian RB and wild type (WT) isolates and compared to previously analyzed TSWV strains with RB properties from different geographical origins. Phylogenetic analysis demonstrated that the different RB strains had the closest relationship with the local WT isolates and there is no conserved mutation present in all the NSs genes of RB isolates from different geographical origins. According to these results, we concluded that the RB isolates evolved separately in geographic point of view, and also according to the RB mechanism. PMID:25331341

  12. Assessment of genetic diversity among Chinese upland cottons with Fusarium and/or Verticillium wilts resistance by AFLP and SSR markers

    Institute of Scientific and Technical Information of China (English)

    WANG Xingfen; MA Jun; YANG Shuo; ZHANG Guiyin; MA Zhiying

    2007-01-01

    Genetic diversity among 95 Chinese upland cottons with Fusarium and/or Verticillium wilts resistance was estimated using Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeat (SSR) markers.Twenty EcoRI-MseI AFLP and 19 SSR primers with polymorphism were selected to perform the fingerprinting.The results showed that 20 AFLP primer pairs produced a total of 1 480 major bands among 95 genotypes,and 214 were polymorphic bands.The number of total bands per primer pair ranged from 47 to 109,with an average of 74.0.The polymorphism information content (PIC) values for the 20 primer pairs varied from 0.01 (E-ACT/M-CAT) to 0.24 (E-ACA/MCTA),and the average value was 0.09.Nineteen SSR primers generated 89 DNA bands,of which 61 were polymorphic.The total number of alleles per locus varied from 3 to 8,with an average of 4.7.The average PIC value for the SSR amplification products was 0.69.Genetic similarity estimates for the entire data set ranged from 0.978 to 0.998 based on AFLP and SSR bands.It was proved that the close genetic relationship and narrow genetic diversity existed in the tested cultivars.The clustering patterns could not be correlated to the geographic origin,the pedigree and common parentage of the cultivars.

  13. Comparative analysis of chrysanthemum transcriptome in response to three RNA viruses: Cucumber mosaic virus, Tomato spotted wilt virus and Potato virus X.

    Science.gov (United States)

    Choi, Hoseong; Jo, Yeonhwa; Lian, Sen; Jo, Kyoung-Min; Chu, Hyosub; Yoon, Ju-Yeon; Choi, Seung-Kook; Kim, Kook-Hyung; Cho, Won Kyong

    2015-06-01

    The chrysanthemum is one of popular flowers in the world and a host for several viruses. So far, molecular interaction studies between the chrysanthemum and viruses are limited. In this study, we carried out a transcriptome analysis of chrysanthemum in response to three different viruses including Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV) and Potato virus X (PVX). A chrysanthemum 135K microarray derived from expressed sequence tags was successfully applied for the expression profiles of the chrysanthemum at early stage of virus infection. Finally, we identified a total of 125, 70 and 124 differentially expressed genes (DEGs) for CMV, TSWV and PVX, respectively. Many DEGs were virus specific; however, 33 DEGs were commonly regulated by three viruses. Gene ontology (GO) enrichment analysis identified a total of 132 GO terms, and of them, six GO terms related stress response and MCM complex were commonly identified for three viruses. Several genes functioning in stress response such as chitin response and ethylene mediated signaling pathway were up-regulated indicating their involvement in establishment of host immune system. In particular, TSWV infection significantly down-regulated genes related to DNA metabolic process including DNA replication, chromatin organization, histone modification and cytokinesis, and they are mostly targeted to nucleosome and MCM complex. Taken together, our comparative transcriptome analysis revealed several genes related to hormone mediated viral stress response and DNA modification. The identified chrysanthemums genes could be good candidates for further functional study associated with resistant to various plant viruses. PMID:25904110

  14. In vitro mutation breeding for the development of bananas with resistance to race 4, Fusarium wilt (Fusarium oxysporum f. sp. cubense)

    International Nuclear Information System (INIS)

    In 1985 the Queensland Department of Primary Industries initiated an in vitro mutation breeding program for banana improvement. The primary objective was to develop a banana that was resistant to race 4, Fusarium wilt which could effectively substitute for the Cavendish cultivars currently grown. Micropropagated bananas were exposed to gamma radiation from a 60Co source and the LD50 was established at 40 Gy. However, the optimal dose selected for irradiating explants was 20 Gy. At this dosage visual changes were apparent and plant survival, at 73%, was sufficiently high to make the technique practical on a larger scale. Over 20,000 plants have been evaluated in the field at our race 4 screening site and nursery at Wamuran in southeastern Queensland. Of the irradiated plants examined only the putative mutants from Dwarf Parfitt, an extra-dwarf variety of Cavendish, show potential as a race 4 resistant Cavendish cultivar. Plants are intermediate in height between Dwarf Cavendish and Williams, the industry standard. Preliminary results indicate the putative mutants are faster cycling and more cold tolerant than Williams. More importantly they also appear to retain the resistance to race 4 shown by the mother plant, Dwarf Parfitt. (author). 16 refs, 2 figs, 2 tabs

  15. 籽用西瓜种质的苗期枯萎病抗性鉴定%Identification of Resistance to Fusarium Wilt in Edible Seed Watermelon Germplasm

    Institute of Scientific and Technical Information of China (English)

    贾宋楠; 王惠林; 郑健; 高强; 苏瑞

    2013-01-01

    Artificial inoculation of 62 inbreds derived from egusi watermelon, edible seed watermelon and regular watermelon to test their resistance to Fusarium wilt. Variation of resistance was observed in the test. Nineteen lines showed intermediate resistance,42 lines showed low level resistance and 1 line was susceptible. High level resistance was not found among the materials tested.%通过室内苗期枯萎病人工接种鉴定,对62份来源于籽用西瓜、黏籽西瓜及普通西瓜杂交后代自交纯系进行枯萎病抗性鉴定,显示出不同自交系之间抗病性的差异,供试材料中鉴定出19份中抗、42份轻抗和1份感病材料,没有发现免疫和高抗材料.

  16. Host-induced post-transcriptional hairpin RNA-mediated gene silencing of vital fungal genes confers efficient resistance against Fusarium wilt in banana.

    Science.gov (United States)

    Ghag, Siddhesh B; Shekhawat, Upendra K S; Ganapathi, Thumballi R

    2014-06-01

    Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is among the most destructive diseases of banana (Musa spp.). Because no credible control measures are available, development of resistant cultivars through genetic engineering is the only option. We investigated whether intron hairpin RNA (ihpRNA)-mediated expression of small interfering RNAs (siRNAs) targeted against vital fungal genes (velvet and Fusarium transcription factor 1) in transgenic banana could achieve effective resistance against Foc. Partial sequences of these two genes were assembled as ihpRNAs in suitable binary vectors (ihpRNA-VEL and ihpRNA-FTF1) and transformed into embryogenic cell suspensions of banana cv. Rasthali by Agrobacterium-mediated genetic transformation. Eleven transformed lines derived from ihpRNA-VEL and twelve lines derived from ihpRNA-FTF1 were found to be free of external and internal symptoms of Foc after 6-week-long greenhouse bioassays. The five selected transgenic lines for each construct continued to resist Foc at 8 months postinoculation. Presence of specific siRNAs derived from the two ihpRNAs in transgenic banana plants was confirmed by Northern blotting and Illumina sequencing of small RNAs derived from the transgenic banana plants. The present study represents an important effort in proving that host-induced post-transcriptional ihpRNA-mediated gene silencing of vital fungal genes can confer efficient resistance against debilitating pathogens in crop plants. PMID:24476152

  17. The movement protein (NSm) of Tomato spotted wilt virus is the avirulence determinant in the tomato Sw-5 gene-based resistance.

    Science.gov (United States)

    Peiró, Ana; Cañizares, M Carmen; Rubio, Luis; López, Carmelo; Moriones, Enrique; Aramburu, José; Sánchez-Navarro, Jesús

    2014-10-01

    The avirulence determinant triggering the resistance conferred by the tomato gene Sw-5 against Tomato spotted wilt virus (TSWV) is still unresolved. Sequence comparison showed two substitutions (C118Y and T120N) in the movement protein NSm present only in TSWV resistance-breaking (RB) isolates. In this work, transient expression of NSm of three TSWV isolates [RB1 (T120N), RB2 (C118Y) and non-resistance-breaking (NRB)] in Nicotiana benthamiana expressing Sw-5 showed a hypersensitive response (HR) only with NRB. Exchange of the movement protein of Alfalfa mosaic virus (AMV) with NSm supported cell-to-cell and systemic transport of the chimeric AMV RNAs into N. tabacum with or without Sw-5, except for the constructs with NBR when Sw-5 was expressed, although RB2 showed reduced cell-to-cell transport. Mutational analysis revealed that N120 was sufficient to avoid the HR, but the substitution V130I was required for systemic transport. Finally, co-inoculation of RB and NRB AMV chimeric constructs showed different prevalence of RB or NBR depending on the presence or absence of Sw-5. These results indicate that NSm is the avirulence determinant for Sw-5 resistance, and mutations C118Y and T120N are responsible for resistance breakdown and have a fitness penalty in the context of the heterologous AMV system. PMID:24690181

  18. Inoculation of tomato seedlings with Trichoderma Harzianum and Arbuscular Mycorrhizal Fungi and their effect on growth and control of wilt in tomato seedlings

    Directory of Open Access Journals (Sweden)

    Margaret W. Mwangi

    2011-06-01

    Full Text Available A green house study was conducted to investigate the ability of an isolate of Trichoderma harzianum (P52 and arbuscular mycorrhizal fungi (AMF in enhancing growth and control of a wilt pathogen caused by Fusarium oxysporum f. sp. lycopersici in tomato seedlings. The plants were grown in plastic pots filled with sterilized soils. There were four treatments applied as follows; P52, AMF, AMF + P52 and a control. A completely randomized design was used and growth measurements and disease assessment taken after 3, 6 and 9 weeks. Treatments that significantly (P < 0.05 enhanced heights and root dry weights were P52, AMF and a treatment with a combination of both P52 and AMF when compared the control. The treatment with both P52 and AMF significantly (P < 0.05 enhanced all growth parameters (heights; shoot and root dry weight investigated compared to the control. Disease severity was generally lower in tomato plants grown with isolate P52 and AMF fungi either individually or when combined together, though the effect was not statistically significant (P0.05. A treatment combination of P52 + AMF had less trend of severity as compared to each individual fungus. T. harzianum and AMF can be used to enhance growth in tomato seedlings.

  19. Cognitive outcome in adults after bacterial meningitis.

    NARCIS (Netherlands)

    Hoogman, M.; Beek, D. van de; Weisfelt, M.; Gans, J. de; Schmand, B.

    2007-01-01

    OBJECTIVE: To evaluate cognitive outcome in adult survivors of bacterial meningitis. METHODS: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy c

  20. Spatial distribution of marine airborne bacterial communities

    OpenAIRE

    Seifried, Jasmin S; Wichels, Antje; Gerdts, Gunnar

    2015-01-01

    The spatial distribution of bacterial populations in marine bioaerosol samples was investigated during a cruise from the North Sea to the Baltic Sea via Skagerrak and Kattegat. The analysis of the sampled bacterial communities with a pyrosequencing approach revealed that the most abundant phyla were represented by the Proteobacteria (49.3%), Bacteroidetes (22.9%), Actinobacteria (16.3%), and Firmicutes (8.3%). Cyanobacteria were assigned to 1.5% of all bacterial reads. A core of 37 bacterial ...

  1. Bacterial population genetics, evolution and epidemiology.

    OpenAIRE

    Spratt, B. G.; Maiden, M C

    1999-01-01

    Asexual bacterial populations inevitably consist of an assemblage of distinct clonal lineages. However, bacterial populations are not entirely asexual since recombinational exchanges occur, mobilizing small genome segments among lineages and species. The relative contribution of recombination, as opposed to de novo mutation, in the generation of new bacterial genotypes varies among bacterial populations and, as this contribution increases, the clonality of a given population decreases. In con...

  2. Population Genomics and the Bacterial Species Concept

    OpenAIRE

    Riley, Margaret A.; Lizotte-Waniewski, Michelle

    2009-01-01

    In recent years, the importance of horizontal gene transfer (HGT) in bacterial evolution has been elevated to such a degree that many bacteriologists now question the very existence of bacterial species. If gene transfer is as rampant as comparative genomic studies have suggested, how could bacterial species survive such genomic fluidity? And yet, most bacteriologists recognize, and name, as species, clusters of bacterial isolates that share complex phenotypic properties. The Core Genome Hypo...

  3. Filtration properties of bacterial cellulose membranes

    OpenAIRE

    Lehtonen, Janika

    2015-01-01

    Bacterial cellulose has the same molecular formula as cellulose from plant origin, but it is characterized by several unique properties including high purity, crystallinity and mechanical strength. These properties are dependent on parameters such as the bacterial strain used, the cultivation conditions and post-growth processing. The possibility to achieve bacterial cellulose membranes with different properties by varying these parameters could make bacterial cellulose an interesting materi...

  4. Bacterial leaching of Pb -metallurgical wastes

    OpenAIRE

    Fečko, Peter; Janáková, Iva; Pertile, Eva; Kulová, Eliška

    2011-01-01

    The aim of this paper is verification of application of bacterial leaching and calcination to recover heavy metals from metallurgical wastes - matte from metallurgical plant Kovohute Pribram. For bacterial leaching a pure bacterial culture of Acidithiobacillus ferrooxidans was used. For a verification test an original sample of matte and matte from 2004 year were used. This paper further shows changes in the samples after bacterial leaching and after calcination. The paper results...

  5. Siderophore-mediated iron acquisition influences motility and is required for full virulence of the xylem-dwelling bacterial phytopathogen Pantoea stewartii subsp. stewartii.

    Science.gov (United States)

    Burbank, Lindsey; Mohammadi, Mojtaba; Roper, M Caroline

    2015-01-01

    Iron is a key micronutrient for microbial growth but is often present in low concentrations or in biologically unavailable forms. Many microorganisms overcome this challenge by producing siderophores, which are ferric-iron chelating compounds that enable the solubilization and acquisition of iron in a bioactive form. Pantoea stewartii subsp. stewartii, the causal agent of Stewart's wilt of sweet corn, produces a siderophore under iron-limiting conditions. The proteins involved in the biosynthesis and export of this siderophore are encoded by the iucABCD-iutA operon, which is homologous to the aerobactin biosynthetic gene cluster found in a number of enteric pathogens. Mutations in iucA and iutA resulted in a decrease in surface-based motility that P. stewartii utilizes during the early stages of biofilm formation, indicating that active iron acquisition impacts surface motility for P. stewartii. Furthermore, bacterial movement in planta is also dependent on a functional siderophore biosynthesis and uptake pathway. Most notably, siderophore-mediated iron acquisition is required for full virulence in the sweet corn host, indicating that active iron acquisition is essential for pathogenic fitness for this important xylem-dwelling bacterial pathogen. PMID:25326304

  6. Bacterial oesophagitis in an immunocompromised patient.

    OpenAIRE

    Radhi, J M; Schweiger, F

    1994-01-01

    Bacterial oesophagitis is an uncommon and poorly described entity affecting particularly the immunosuppressed patient. The diagnosis rests on the demonstration of bacterial invasion of the oesophageal wall in the absence of other pathological processes. The causative organisms usually are Gram-positive cocci and there may be associated bacteraemia. The case report describes a leukaemic patient with bacteraemic bacterial oesophagitis.

  7. Tobacco use increases susceptibility to bacterial infection

    OpenAIRE

    Demuth Donald R; Bagaitkar Juhi; Scott David A

    2008-01-01

    Abstract Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacteri...

  8. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation. PMID:26566111

  9. Dynamics of bacterial gene regulation

    Science.gov (United States)

    Narang, Atul

    2009-03-01

    The phenomenon of diauxic growth is a classical problem of bacterial gene regulation. The most well studied example of this phenomenon is the glucose-lactose diauxie, which occurs because the expression of the lac operon is strongly repressed in the presence of glucose. This repression is often explained by appealing to molecular mechanisms such as cAMP activation and inducer exclusion. I will begin by analyzing data showing that these molecular mechanisms cannot explain the strong lac repression because they exert a relatively weak effect. I will then present a minimal model accounting only for enzyme induction and dilution, which yields strong repression despite the absence of catabolite repression and inducer exclusion. The model also explains the growth patterns observed in batch and continuous cultures of various bacterial strains and substrate mixtures. The talk will conclude with a discussion of the experimental evidence regarding positive feedback, the key component of the minimal model.

  10. Collective Functionality through Bacterial Individuality

    Science.gov (United States)

    Ackermann, Martin

    According to the conventional view, the properties of an organism are a product of nature and nurture - of its genes and the environment it lives in. Recent experiments with unicellular organisms have challenged this view: several molecular mechanisms generate phenotypic variation independently of environmental signals, leading to variation in clonal groups. My presentation will focus on the causes and consequences of this microbial individuality. Using examples from bacterial genetic model systems, I will first discuss different molecular and cellular mechanisms that give rise to bacterial individuality. Then, I will discuss the consequences of individuality, and focus on how phenotypic variation in clonal populations of bacteria can promote interactions between individuals, lead to the division of labor, and allow clonal groups of bacteria to cope with environmental uncertainty. Variation between individuals thus provides clonal groups with collective functionality.

  11. Bacterial survival in Martian conditions

    CERN Document Server

    D'Alessandro, Giuseppe Galletta; Giulio Bertoloni; Maurizio

    2010-01-01

    We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. Our LISA environmental chambers can reproduce the conditions of many Martian locations near the surface trough changes of temperature, pressure, UV fluence and atmospheric composition. Both simulators are open to collaboration with other laboratories interested in performing experiments on many kind of samples (biological, minerals, electronic) in situations similar to that of the red planet. Inside LISA we have studied the survival of several bacterial strains and endospores. We verified that the UV light is the major re...

  12. Bacterial streamers in curved microchannels

    Science.gov (United States)

    Rusconi, Roberto; Lecuyer, Sigolene; Guglielmini, Laura; Stone, Howard

    2009-11-01

    Biofilms, generally identified as microbial communities embedded in a self-produced matrix of extracellular polymeric substances, are involved in a wide variety of health-related problems ranging from implant-associated infections to disease transmissions and dental plaque. The usual picture of these bacterial films is that they grow and develop on surfaces. However, suspended biofilm structures, or streamers, have been found in natural environments (e.g., rivers, acid mines, hydrothermal hot springs) and are always suggested to stem from a turbulent flow. We report the formation of bacterial streamers in curved microfluidic channels. By using confocal laser microscopy we are able to directly image and characterize the spatial and temporal evolution of these filamentous structures. Such streamers, which always connect the inner corners of opposite sides of the channel, are always located in the middle plane. Numerical simulations of the flow provide evidences for an underlying hydrodynamic mechanism behind the formation of the streamers.

  13. Immunization by a bacterial aerosol

    OpenAIRE

    Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; DeRousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R.; Miller, Rich; Fourie, P. Bernard; Hickey, Anthony; Edwards, David

    2008-01-01

    By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried “nanomicroparticle” vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the form...

  14. Small intestinal bacterial overgrowth syndrome

    OpenAIRE

    Jan Bures, Jiri Cyrany, Darina Kohoutova, Miroslav Förstl, Stanislav Rejchrt, Jaroslav Kvetina, Viktor Vorisek, Marcela Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestina...

  15. Small intestinal bacterial overgrowth syndrome.

    OpenAIRE

    Bures, J.; Cyrany, J.; Kohoutova, D.; Förstl, M.; Rejchrt, S.; Kvetina, J.; Vorisek, V.; Kopacova, M.

    2010-01-01

    Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestina...

  16. Bacterial degradation of bile salts

    OpenAIRE

    Philipp, Bodo

    2011-01-01

    Bile salts are surface-active steroid compounds. Their main physiological function is aiding the digestion of lipophilic nutrients in intestinal tracts of vertebrates. Many bacteria are capable of transforming and degrading bile salts in the digestive tract and in the environment. Bacterial bile salt transformation and degradation is of high ecological relevance and also essential for the biotechnological production of steroid drugs. While biotechnological aspects have been reviewed many time...

  17. Bacterial communication and group behavior

    OpenAIRE

    Greenberg, E. Peter

    2003-01-01

    The existence of species-specific and interspecies bacterial cell-cell communication and group organization was only recently accepted. Researchers are now realizing that the ability of these microbial teams to communicate and form structures, known as biofilms, at key times during the establishment of infection significantly increases their ability to evade both host defenses and antibiotics. This Perspective series discusses the known signaling mechanisms, the roles they play in both chroni...

  18. Bacterial survival in Martian conditions

    OpenAIRE

    Galletta, Giuseppe; Bertoloni, Giulio; D'Alessandro, Maurizio

    2010-01-01

    We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. ...

  19. Rheumatoid arthritis and bacterial infections

    OpenAIRE

    N L Prokopjeva; N N Vesikova; I M Marusenko; V A Ryabkov

    2008-01-01

    To study features of bacterial infections course in pts with rheumatoid arthritis (RA) and changes of laboratory measures after focus of infection sanation. Material and methods. 46 pts with definite rheumatoid arthritis were examined at the time of comorbid infection (Cl) detection and after infection focus sanation. Bacteriological test with evaluation of flora sensitivity to antibiotics by disco-diffusion method was performed at baseline and after the course of antibacterial therapy to ass...

  20. Molecular approaches for bacterial azoreductases

    OpenAIRE

    Montira Leelakriangsak

    2013-01-01

    Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N-) in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study...

  1. Biotechnological applications of bacterial cellulases

    OpenAIRE

    Esther Menendez; Paula Garcia-Fraile; Raul Rivas

    2015-01-01

    Cellulases have numerous applications in several industries, including biofuel production, food and feed industry, brewing, pulp and paper, textile, laundry, and agriculture.Cellulose-degrading bacteria are widely spread in nature, being isolated from quite different environments. Cellulose degradation is the result of a synergic process between an endoglucanase, an exoglucanase and a,β-glucosidase. Bacterial endoglucanases degrade ß-1,4-glucan linkages of cellulose amorphous zones, mean...

  2. Population dynamics of bacterial persistence

    OpenAIRE

    Patra, Pintu

    2014-01-01

    The life of microorganisms is characterized by two main tasks, rapid growth under conditions permitting growth and survival under stressful conditions. The environments, in which microorganisms dwell, vary in space and time. The microorganisms innovate diverse strategies to readily adapt to the regularly fluctuating environments. Phenotypic heterogeneity is one such strategy, where an isogenic population splits into subpopulations that respond differently under identical environments. Bacteri...

  3. Bacterial infections: antibiotics and decontamination.

    Science.gov (United States)

    Gould, Dinah

    Infectious disease is caused by bacteria, viruses, fungi, protozoa and micro-organisms including the mycoplasmas, rickettsiae and chlamydiae. Most of the infections commonly encountered in the UK are caused either by bacteria or viruses. This article describes bacterial structure and function to explain how antibiotics work and the processes of decontamination such as cleaning, disinfection and sterilisation, which are important in infection control. PMID:15224613

  4. Small intestinal bacterial overgrowth syndrome

    Institute of Scientific and Technical Information of China (English)

    Jan; Bures; Jiri; Cyrany; Darina; Kohoutova; Miroslav; Frstl; Stanislav; Rejchrt; Jaroslav; Kvetina; Viktor; Vorisek; Marcela; Kopacova

    2010-01-01

    Human intestinal microbiota create a complex polymi-crobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO).SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastro-intestinal tract. There...

  5. Bacterial meningitis by streptococcus agalactiae

    OpenAIRE

    Villarreal-Velásquez Tatiana Paola; Cortés-Daza César Camilo

    2012-01-01

    Introduction: bacterial meningitis is an infectious disease considered a medicalemergency. The timely management has an important impact on the evolution of thedisease. Streptococcus agalactiae, a major causative agent of severe infections innewborns can colonize different tissues, including the central nervous system.Case report: Male patient 47 years old from rural areas, with work activity as amilker of cattle, referred to tertiary care, with disorientation, neck stiffness, and grandmal se...

  6. Organization of the bacterial chromosome.

    OpenAIRE

    Krawiec, S.; Riley, M

    1990-01-01

    Recent progress in studies on the bacterial chromosome is summarized. Although the greatest amount of information comes from studies on Escherichia coli, reports on studies of many other bacteria are also included. A compilation of the sizes of chromosomal DNAs as determined by pulsed-field electrophoresis is given, as well as a discussion of factors that affect gene dosage, including redundancy of chromosomes on the one hand and inactivation of chromosomes on the other hand. The distinction ...

  7. Bacterial sex in dental plaque

    Directory of Open Access Journals (Sweden)

    Ingar Olsen

    2013-06-01

    Full Text Available Genes are transferred between bacteria in dental plaque by transduction, conjugation, and transformation. Membrane vesicles can also provide a mechanism for horizontal gene transfer. DNA transfer is considered bacterial sex, but the transfer is not parallel to processes that we associate with sex in higher organisms. Several examples of bacterial gene transfer in the oral cavity are given in this review. How frequently this occurs in dental plaque is not clear, but evidence suggests that it affects a number of the major genera present. It has been estimated that new sequences in genomes established through horizontal gene transfer can constitute up to 30% of bacterial genomes. Gene transfer can be both inter- and intrageneric, and it can also affect transient organisms. The transferred DNA can be integrated or recombined in the recipient's chromosome or remain as an extrachromosomal inheritable element. This can make dental plaque a reservoir for antimicrobial resistance genes. The ability to transfer DNA is important for bacteria, making them better adapted to the harsh environment of the human mouth, and promoting their survival, virulence, and pathogenicity.

  8. Bacterial strategies for chemotaxis response.

    Science.gov (United States)

    Celani, Antonio; Vergassola, Massimo

    2010-01-26

    Regular environmental conditions allow for the evolution of specifically adapted responses, whereas complex environments usually lead to conflicting requirements upon the organism's response. A relevant instance of these issues is bacterial chemotaxis, where the evolutionary and functional reasons for the experimentally observed response to chemoattractants remain a riddle. Sensing and motility requirements are in fact optimized by different responses, which strongly depend on the chemoattractant environmental profiles. It is not clear then how those conflicting requirements quantitatively combine and compromise in shaping the chemotaxis response. Here we show that the experimental bacterial response corresponds to the maximin strategy that ensures the highest minimum uptake of chemoattractants for any profile of concentration. We show that the maximin response is the unique one that always outcompetes motile but nonchemotactic bacteria. The maximin strategy is adapted to the variable environments experienced by bacteria, and we explicitly show its emergence in simulations of bacterial populations in a chemostat. Finally, we recast the contrast of evolution in regular vs. complex environments in terms of minimax vs. maximin game-theoretical strategies. Our results are generally relevant to biological optimization principles and provide a systematic possibility to get around the need to know precisely the statistics of environmental fluctuations. PMID:20080704

  9. Bacterial adhesion and biofilms on surfaces

    Institute of Scientific and Technical Information of China (English)

    Trevor Roger Garrett; Manmohan Bhakoo; Zhibing Zhang

    2008-01-01

    Bacterial adhesion has become a significant problem in industry and in the domicile,and much research has been done for deeper understanding of the processes involved.A generic biological model of bacterial adhesion and population growth called the bacterial biofilm growth cycle,has been described and modified many times.The biofilm growth cycle encompasses bacterial adhesion at all levels,starting with the initial physical attraction of bacteria to a substrate,and ending with the eventual liberation of cell dusters from the biofilm matrix.When describing bacterial adhesion one is simply describing one or more stages of biofilm development,neglecting the fact that the population may not reach maturity.This article provides an overview of bacterial adhesion.cites examples of how bac-terial adhesion affects industry and summarises methods and instrumentation used to improve our understanding of the adhesive prop-erties of bacteria.

  10. Ponto de murcha permanente de soja, feijão e plantas daninhas Permanent wilting point of soybean, bean and weeds

    Directory of Open Access Journals (Sweden)

    S.O. Procópio

    2004-03-01

    Full Text Available Objetivou-se neste trabalho determinar o ponto de murcha permanente das culturas da soja e do feijão e de plantas daninhas de grande ocorrência nas áreas agrícolas do Brasil. Os tratamentos foram constituídos por seis espécies, sendo duas cultivadas, Glycine max e Phaseolus vulgaris, e quatro de plantas daninhas - Euphorbia heterophylla (plantas suscetíveis e resistentes a herbicidas inibidores de ALS, Bidens pilosa e Desmodium tortuosum -, com duas épocas de indução de estresse hídrico (pré-florescimento e início do enchimento de grãos. Os solos contidos nos vasos foram mantidos próximos a 80% da capacidade de campo até as épocas predeterminadas para o início do estresse hídrico. A partir desta etapa não foram mais molhadas e, ao primeiro sinal de murcha das espécies, no final do dia, os respectivos vasos foram transferidos para câmara escura, com umidade relativa do ar próxima a 100%, para constatação do não-retorno definitivo da turgidez [ponto de murcha permanente (PMP]. Nesse ponto, foi coletada uma amostra (sem raízes do solo para a determinação do teor de água pelo método gravimétrico. A partir dos valores de umidade determinados nas amostras de solo, para cada tratamento avaliado, caracterizou-se, por meio da curva de retenção de umidade do solo, o potencial da água no PMP. Na fase de enchimento de grãos, o PMP das plantas de B. pilosa ocorreu quando o potencial de retenção de água do solo era mais negativo em relação às outras espécies avaliadas, demonstrando que, neste estádio de desenvolvimento, esta espécie apresenta maior eficiência na extração de água do solo e, conseqüentemente, maior potencial competitivo do que as outras avaliadas.This work aimed to determine the permanent wilting point of soybean, and bean crops and weeds of high occurrence in Brazilian agricultural areas. The treatments consisted of two crops, Glycine max and Phaseolus vulgaris, and four weed species: Euphorbia

  11. 萎蔫处理对花椰菜茎叶可青贮性的影响%The Effects of Wilting Processing on the Silage Quality of Cauliflower Stems and Leaves

    Institute of Scientific and Technical Information of China (English)

    何元翔; 汪建旭; 冯炜弘; 杨道兰

    2013-01-01

    This experiment takes the stems and leaves of cauliflower as raw materials to study the silage quality by wilting processing and adding the silage enzymes and Lactobacillus powder as silage additives. The results showed that the fermentation of the untreated cauliflower stems and leaves (89% water content) have lower sensory score (the second level, can)and fermentation freund score (only 10 ,failed). Their nutritional quality and silage fermentation quality are lower than that of the wilting processing, so they are not appropriate for direct fermentation. The fermentation of silages (75%, 55%) through the wilting processing have a better sensory score (the frist level, good) and fermentation freund score (64,61 good) , so they are more appropriate for silage fermentation.%以花椰菜(Brassica oleracea var.botrytis)废弃茎叶为原料,通过凋萎处理和添加青黄贮酶、乳酸菌粉青贮添加剂,探讨花椰菜茎叶的可青贮性.结果表明:未经处理的花椰菜茎叶(含水量89%)发酵后,感官评分为2级(尚可),发酵弗氏评分仅为10(不合格),其营养品质、发酵品质均低于萎蔫后青贮饲料,说明其并不适宜直接青贮发酵;而萎蔫处理后的原料(含水量75%、55%)在青贮发酵后,感官评分为1级(优良),发酵弗氏评分分别为64、61(良好),营养及发酵品质好,适宜青贮发酵.

  12. Identification of a novel small cysteine-rich protein in the fraction from the biocontrol Fusarium oxysporum strain CS-20 that mitigates Fusarium wilt symptoms and triggers defense responses in tomato

    Directory of Open Access Journals (Sweden)

    Larisa A. Shcherbakova

    2016-01-01

    Full Text Available The biocontrol effect of the nonpathogenic F. oxysporum strain CS-20 against the tomato wilt pathogen F. oxysporum f. sp. lycopersici (FOL has been previously reported to be primarily plant-mediated. This study shows that CS-20 produces proteins, which elicit defense responses in tomato plants. Three protein-containing fractions were isolated from CS-20 biomass using size exclusion chromatography. Exposure of seedling roots to one of these fractions prior to inoculation with pathogenic FOL strains significantly reduced wilt severity. This fraction initiated an ion exchange response in cultured tomato cells resulting in a reversible alteration of extracellular pH; increased tomato chitinase activity, and induced systemic resistance by enhancing PR-1 expression in tomato leaves. Two other protein fractions were inactive in seedling protection. The main polypeptide (designated CS20EP, which was specifically present in the defense-inducing fraction and was not detected in inactive protein fractions, was identified. The nucleotide sequence encoding this protein was determined, and its complete amino acid sequence was deduced from direct Edman degradation (25 N-terminal amino acid residues and DNA sequencing. The CS20EP was found to be a small basic cysteine-rich protein with a pI of 9.87 and 23.43% of hydrophobic amino acid residues. BLAST search in the NCBI database showed that the protein is new; however, it displays 48% sequence similarity with a hypothetical protein FGSG_10784 from F. graminearum strain PH-1. The contribution of CS20EP to elicitation of tomato defense responses resulting in wilt mitigating is discussed.

  13. 黄麻链霉菌 NF0919菌株对草莓枯萎病的生防活性初探%A Primary Study on Biocontrol Activity of Streptomyces corchorusii Strain NF0919 to Strawberry Fusarium Wilt

    Institute of Scientific and Technical Information of China (English)

    陈宏州; 庄义庆; 杨敬辉

    2014-01-01

    采用菌丝生长速率法测定了黄麻链霉菌NF0919发酵液对草莓枯萎病菌的室内毒力,并进行了防治草莓枯萎病的室内盆栽试验。结果表明:NF0919菌株发酵液和申嗪霉素对草莓枯萎病菌菌丝生长抑制的EC50值分别为24.3752和0.4001μg/mL;NF0919菌株发酵上清20倍液和1%申嗪霉素SC 800倍液药后30 d对草莓枯萎病的防效分别为65%和90%。%We determined the indoor toxicity of the fermentation broth of Streptomyces corchorusii strain NF0919 to the pathogen ( Fusarium oxysporum f.sp.fragariae) of strawberry fusarium wilt through adopting mycelial growth rate method, and carried out the indoor pot experiment for the control of strawberry fusarium wilt.The results indicated that the EC50 values of NF0919 fermenta-tion broth and Phenazine-1-carboxylic against the mycelial growth of Fusarium oxysporum f.sp.fragariae were 24.3752 and 0.4001μg/mL respectively.On the 30th day after root-pouring treatment with the 20-fold dilution of fermentation supematant of NF0919 or the 800-fold dilution of 1%Phenazine-1-carboxylic SC, their control effect on strawberry fusarium wilt reached 65%or 90%, respectively.

  14. Determination of Tolerance Levels of Cotton Genotypes Obtained from F6-F7 Generation against Verticillium Wilt Disease Caused by Verticillium dahliae Kleb.

    Directory of Open Access Journals (Sweden)

    Oktay EROĞAN

    2013-05-01

    Full Text Available The susceptibility of cotton genotypes obtained from F6 and F7 generations to Verticillium wilt (VW disease (Verticillium dahliae Kleb., was studied under artificial and natural infestation during 2009 and 2010 growing seasons at the Cotton Research Institute’s, Nazilli, Aydın, Turkey. In this study, fifteen cotton breeding lines and two control varieties were used as plant material. During the cotton growing season, foliar disease index (FDI, vascular disease index (VDI and pot disease index (PDI were observed in addition to seed cotton yield and some fiber quality characteristics. According to the obtained results, disease severity (DS values observed in pot experiments were higher than field trials. In terms of DS, ‘Tamcot CD3H’ × ‘Tamcot Luxor-III’, ‘Maraş92’ × ‘Tamcot Sphinx’ and ‘Sayar 314’ × ‘Stoneville 453-I’ breeding lines exhibited similar values with tolerant ‘Carmen’ variety. ‘Tamcot CD3H’ × ‘Tamcot Sphinx’, ‘Sayar 314’ × ‘Stoneville 453-I’, ‘Sayar 314’ × ‘Stoneville 453-II’ and ‘Stoneville 453’ × ‘Tamcot Sphinx’ breeding lines which gave similar DS values with tolerant ‘Carmen’ variety were statistically on the same group with ‘Carmen’ variety suitable to seed cotton yield. In this study, the disease tolerant breeding lines had higher fiber strength values than susceptible lines, the lowest fiber strength value obtained from ‘Cukurova 1518’ susceptible variety.

  15. Screening of watermelon rootstocks resistant to physiological wilt disease%抗生理性凋萎症西瓜砧木筛选试验

    Institute of Scientific and Technical Information of China (English)

    韦志扬; 韦莉萍; 韦昌联; 覃泽林; 麻小燕; 何毅; 温国泉

    2012-01-01

    [目的]筛选抗生理性凋萎症的西瓜嫁接砧木品种应用于生产.[方法]选用葫芦类、南瓜类、冬瓜类及野生西瓜类等17个砧木与广西三号无籽西瓜进行嫁接试验、田间栽培试验,观察嫁接成活率及嫁接栽培对西瓜生长势、抗病性、产量和果实品质的影响.[结果]嫁接成活率葫芦类91.20%~95.60%,南瓜类73.20%~80.40%,冬瓜类81.20%~86.40%,野生西瓜类82.40%~91.20%;嫁接组合生长势强的砧木品种为广西本地葫芦、杂交葫芦、大蒲瓜、超丰F1、日本南瓜、铁力金钢白籽南瓜、白籽南瓜、农友野生西瓜、伙伴野生西瓜;坐果容易的砧木品种为广西本地葫芦、杂交葫芦、大蒲瓜、超丰F1、日本南瓜、铁力金钢白籽南瓜、白籽南瓜、伙伴野生西瓜;高抗生理性凋萎症的砧木品种为白籽南瓜、铁力金钢白籽南瓜、日本南瓜、广西本地葫芦、杂交葫芦、大蒲瓜、超丰F1、伙伴野生西瓜;产量在22500.00 kg/ha以上且按产量由高到低排序为白籽南瓜、铁力金钢白籽南瓜、广西本地葫芦、日本南瓜、伙伴野生西瓜、杂交葫芦、大蒲瓜;17个嫁接组合的西瓜果实在瓤色、果实质地、口感风味方面差别不明显,但在果实可溶性固形物含量、瓜形及剖面、皮厚等方面存在一定差异.[结论]广西本地葫芦、杂交葫芦、白籽南瓜、伙伴野生西瓜与广西三号无籽西瓜嫁接表现高抗西瓜生理性凋萎症,且综合性状表现优良,可进一步扩大试验和示范.%This research screened the grafted watermelon rootstock varieties resistant to physiological wilt disease in order to apply relevant information to watermelon production. [ Method]Seventeen different stocks of Lagenaria siceraria, squash, Benincasa, and wild Citrullus vulgaris were selected to undergo the grafting test and filed cultivation test with seedless watermelon Guangxi 3; the relevant

  16. Resposta do algodoeiro à seleção para resistência à fusariose, em condições de campo Response of cotton to selection for resistance to fusarium wilt in field conditions

    Directory of Open Access Journals (Sweden)

    Imre L. Gridi-Papp

    1973-01-01

    Full Text Available Um processo contínuo de testes de algodoeiros, em condições naturais de infestação por Fusarrum oxysporum f. vasinfectum (Atk. Snyder & Hansen, é descrito e discutido. Consiste, basicamente, em ciclos de seleção de três anos. Seleções individuais são feitas no primeiro ano, e as progenies são testadas no segundo. Ainda no segundo ano são realizadas seleções massais nas melhores progênies, e as populações descendentes são estudadas no terceiro ano. A avaliação dos resultados obtidos em dois ciclos consecutivos mostrou que o método foi eficiente, incrementando, em qualquer dos materiais estudados, a tolerância e a resistência à moléstia, expressas em índices apropriados. O progresso foi maior em material suscetível de origem do que em material resistente. Tal diferença diminuiu quando a intensidade da fusariose aumentou Também os ganhos, em valor absoluto, foram menores em condições de maior gravidade da moléstia.A process of continuous selection and testing for fusarium wilt resistance of cotton is described and its efficiency discussed. It essentially consists in individual selection, progeny tests, mass selection in the best progenies and testing of the corresponding MS in the third year. Individual selections may come from the breeding programs as well as from crop fields and artificial inoculation in green-houses. All the tests are made in field conditions. Data of 1969 to 1971, obtained in two cycles of selection, showed that the process described was efficient in increasing both tolerance and resistance to wilt. The increase was larger in the case of originally susceptible material than in that of resistant one. This difference was smaller in years of more intense wilt. Also the actual values of increases were smaller in such years. The results suggest that fusarium wilt resistance, in cotton, may be a matter of concentration of minor genes in the population, rather than of the presence of a few major genes.

  17. 木霉菌株对香蕉枯萎病病原菌抑菌效果测定%Antibacterial effects of Trichoderma spp. strains on banana Fusarium wilt (Fusarium Oxysporum f.sp. Cubense)

    Institute of Scientific and Technical Information of China (English)

    莫贱友; 郭堂勋; 胡凤云; 黄穗萍; 李焜华

    2012-01-01

    [Objective]Antibacterial effects of 17 Trichoderma spp. strains on banana Fusarium wilt were identified to provide references for controlling banana Fusarium wilt effectively by using Trichoderma spp. [Method]Three inoculation methods (viz. Inoculation of the pathogen ahead of the Trichoderma spp.; inoculation of the Trichoderma spp. ahead of the pathogen, inoculation of the pathogen and the Trichoderma spp. at the same time) were used to mensurate antibacterial effect of Trichoderma spp. strains on banana Fusarium wilt. [Result]Under the three different inoculation methods, the Trichoderma spp. strains of 0026 Ⅰ , 0024 Ⅱ and 0018 Ⅱ ① had the highest antibacterial effects, with the antibacterial rates of over 90.00%, followed by 0023 Ⅰ ② 0028 Ⅱ ② and 0025 Ⅱ with the rates of over 80.00%. [Conclusion]The Trichoder-ma spp. strains of 0026 Ⅰ , 0024 Ⅱ ,001811①, 0023 I ②, 0028Ⅱ②and 0025 Ⅱ are all applicable in biological control of banana Fusarium wilt.%[目的]明确17个木霉菌株对香蕉枯萎病病原菌1号生理小种的抑菌效果,为利用木霉菌株防治香蕉枯萎病提供依据.[方法]分别采用先接病原菌后接木霉菌、先接木霉菌后接病原菌和同时接种木霉菌和病原菌的3种接种方式,进行木霉菌株对香蕉枯萎病病原菌抑菌效果测定.[结果]3种接种方式下,木霉菌株0026 Ⅰ、00181Ⅱ①和0024Ⅱ对香蕉枯萎病菌均有较强的抑菌作用,抑菌效果在90.00%以上;0023 Ⅰ②、0028Ⅱ②和0025Ⅱ次之,抑菌效果均在80.00%以上.[结论]木霉菌株0026Ⅰ、0024Ⅱ、0018Ⅱ①、0023Ⅰ②、0028Ⅱ②和0025Ⅱ均在香蕉枯萎病生物防治中加以开发应用.

  18. 韭菜对巴西香蕉枯萎病发生的抑制作用%Suppressive Effects of Chinese Leek (Allium tuberosum) on Fusarium Wilt Disease of Baxi Banana

    Institute of Scientific and Technical Information of China (English)

    黄永红; 李春雨; 左存武; 梅眉; 易干军

    2011-01-01

    采取田间试验、盆栽试验及实验室研究相结合的方法,研究了韭菜对香蕉枯萎病的防控效果。田间试验表明,韭菜之后轮作香蕉,第1年香蕉枯萎病平均发病率仅为1.73%(对照为52%)。盆栽试验表明,韭菜处理对香蕉枯萎病发病抑制率为85.9%,病情抑制率为82%;而且韭菜叶片的水提取液对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense,FOC)孢子增殖抑制率为91.2%,对其致死率为86.97%。本研究表明,韭菜轮作香蕉的种植模式是一种防控香蕉枯萎病的有效途径,而且韭菜及其制剂有望发展成为防%Inhibitory effects of Chinese leek(Allium tuberosum)on Fusarium wilt of Baxi banana(Musa AAA Cavendish subgroup) were investigated with field tests,experiments in greenhouse and laboratory.Field tests showed that the disease incidence of Fusarium wilt in the banana planted immediately after harvesting Chinese leek was decreased to 1.73% in comparison of 52% in control in the first year.Pot experiments demonstrated that Chinese leek inhibited disease incidence and disease severity by 85.9% and 82%,respectively.Laboratory experiments showed that 10 mL water extract of Chinese leek suppressed proliferation of the spores of Fusarium oxysporum f.sp.cubense by 91.2% and the incidence of lethal incidence was 86.97%.These results indicated that Chinese leek-banana rotation system was an efficient way to control banana Fusarium wilt,and Chinese leek and its productions are promising to be environment-friendly biology agents for banana Fusarium wilt control.

  19. Seleção do algodoeiro para resistência à fusariose em área onde ocorre doença semelhante em plantas de labelabe (Dolichos lablab L. Selection of cotton plants resistant to fusarium wilt in a plot where similar disease occurs on hyacinth bean (Dolichos lablab L.

    Directory of Open Access Journals (Sweden)

    Imre L. Gridi-Papp

    1970-01-01

    Full Text Available Em área de Latossolo Roxo, localizada na Estação Experimental "Theodureto de Camargo", em Campinas, verificou-se incidência de doença provocando "murcha", com sintomas internos caracterizados pelo escurecimento dos vasos, sucessivamente em plantas de labelabe e em algodoeiro. Em ambas as espécies vegetais determinou-se a presença de fungos do gênero Fusarium, mediante isolamento feito em plantas doentes. Seleções, feitas na referida área, de plantas pertencentes a linhagem de algodoeiro suscetível à murcha de Fusariumderam origem a linhagens que revelaram apreciável resistência quando testadas em solo infestado por Fusarium oxysporum f.vasinfectum (Atk. Snyder & Hansen. São discutidos aspectos relacionados com a possível descoberta de nova fonte genética de resistência à doença e com a existência desse fungo sob infestação natural na Estação Experimental mencionada. Também é apontada a possibilidade de serem o algodoeiro e a leguminosa em questão hospedeiras do mesmo agente patogênico.The occurrence of wilt disease, successively in plants of hyacinth bean (Dolichos lablab L. and cotton, was observed in a plot of latosolic B (Terra Roxa soil at the "Theodureto de Camargo" Experiment Station at Campinas, where no Fusarium wilt has been recorded before. Both species presented internal symptoms consisting in darkened vessels. Fungi of the genus Fusarium were isolated from these plants. Plant selection for wilt resistance was made in the above mentioned area where a Fusarium - susceptible variety (IAG 51/1104 of cotton had been planted. The progenies when tested in soils infested by Fusarium oxysporum f. vasinfectum Atk. Snyder & Hansen revealed fair resistance to wilt. IAG 51/1104 comes from a cross between the varieties Delfos and Delta Pineland-10, both wilt susceptible under field conditions of the State of São Paulo. It is likely that the wilt resistance of some of its progeny might have originated by recombination

  20. Continuous monitoring of bacterial attachment

    Science.gov (United States)

    Koeing, D. W.; Mishra, S. K.; Pierson, D. L.

    1994-01-01

    A major concern with the Space Station Freedom (SSF) water supply system is the control of longterm microbial contamination and biofilm development in the water storage and distribution systems. These biofilms have the potential for harboring pathogens as well as microbial strains containing resistance factors that could negatively influence crew health. The proposed means for disinfecting the water system on SSF (iodine) may encourage the selection of resistant strains. In fact, biofilm bacteria were observed in water lines from the Space Shuttle Columbia (OV-102); therefore, an alternative remediation method is required to disinfect spacecraft water lines. A thorough understanding of colonization events and the physiological parameters that will influence bacteria adhesion is required. The limiting factor for development of this technology is the ability to continuously monitor adhesion events and the effects of biocides on sessile bacteria. Methods were developed to allow bacterial adhesion and subsequent biocidal treatment to be monitored continuously. This technique couples automated image analysis with a continuous flow of a bacterial suspension through an optical flow cell. A strain of Pseudomonas cepacia isolated from the water supply of the Space Shuttle Discovery (OV-103) during STS-39 was grown in a nitrogen-limited continuous culture. This culture was challenged continuously with iodine during growth, and the adhesion characteristics of this strain was measure with regard to flow rate. Various biocides (ozone, hypochlorite, and iodine) were added to the flow stream to evaluate how well each chemical removed the bacteria. After biocide treatment, a fresh bacterial suspension was introduced into the flow cell, and the attachment rate was evaluated on the previously treated surface. This secondary fouling was again treated with biocide to determine the efficacy of multiple batch chemical treatments in removing biofilm.

  1. 玉米细菌性枯萎病及其病原菌的检测技术%Bacterial Wilt of Maize and the Detection of Pantoea stewartii subsp.stewartii

    Institute of Scientific and Technical Information of China (English)

    吴琼; 陈枝楠; 范怀忠; 金显忠

    2004-01-01

    玉米细菌性枯萎病是影响玉米生产的重要病害,该病害通过带菌的种子进行远距离传播,对该病菌的检测成为防止和控制该病害的重要手段.介绍现有的检测该病菌的各种方法,即黑色素选择培养法、double-sandwich ELISA以及RAPD-PCR,LCR-PCR,Nested-PCR,multiple PCR和荧光实时PCR等分子生物学检测方法,并对这些方法的特性进行比较和探讨.

  2. Bacterial toxin-antitoxin systems

    OpenAIRE

    Guglielmini, Julien; Van Melderen, Laurence

    2011-01-01

    Toxin-antitoxin (TA) systems are composed of two elements: a toxic protein and an antitoxin which is either an RNA (type I and III) or a protein (type II). Type II systems are abundant in bacterial genomes in which they move via horizontal gene transfer. They are generally composed of two genes organized in an operon, encoding a toxin and a labile antitoxin. When carried by mobile genetic elements, these small modules contribute to their stability by a phenomenon denoted as addiction. Recentl...

  3. Role of quorum sensing in bacterial infections

    OpenAIRE

    Castillo-Juárez, Israel; Maeda, Toshinari; Mandujano-Tinoco, Edna Ayerim; Tomás, María; Pérez-Eretza, Berenice; García-Contreras, Silvia Julieta; Wood, Thomas K.; García-Contreras, Rodolfo

    2015-01-01

    Quorum sensing (QS) is cell communication that is widely used by bacterial pathogens to coordinate the expression of several collective traits, including the production of multiple virulence factors, biofilm formation, and swarming motility once a population threshold is reached. Several lines of evidence indicate that QS enhances virulence of bacterial pathogens in animal models as well as in human infections; however, its relative importance for bacterial pathogenesis is still incomplete. I...

  4. Remodeling bacterial polysaccharides by metabolic pathway engineering

    OpenAIRE

    Yi, Wen; Liu, Xianwei; Li, Yanhong; Li, Jianjun; Xia, Chengfeng; Zhou, Guangyan; Zhang, Wenpeng; Zhao, Wei; Chen, Xi; Wang, Peng George

    2009-01-01

    Introducing structural modifications into biomolecules represents a powerful approach to dissect their functions and roles in biological processes. Bacterial polysaccharides, despite their rich structural information and essential roles in bacterium-host interactions and bacterial virulence, have largely been unexplored for in vivo structural modifications. In this study, we demonstrate the incorporation of a panel of monosaccharide analogs into bacterial polysaccharides in a highly homogenou...

  5. Small molecule control of bacterial biofilms

    OpenAIRE

    Worthington, Roberta J.; Richards, Justin J.; Melander, Christian

    2012-01-01

    Bacterial biofilms are defined as a surface attached community of bacteria embedded in a matrix of extracellular polymeric substances that they have produced. When in the biofilm state, bacteria are more resistant to antibiotics and the host immune response than are their planktonic counterparts. Biofilms are increasingly recognized as being significant in human disease, accounting for 80% of bacterial infections in the body and diseases associated with bacterial biofilms include: lung infect...

  6. Identification of bacterial cells by chromosomal painting.

    OpenAIRE

    Lanoil, B. D.; Giovannoni, S J

    1997-01-01

    Chromosomal painting is a technique for the microscopic localization of genetic material. It has been applied at the subcellular level to identify regions of eukaryotic chromosomes. Here we describe the development of bacterial chromosomal painting (BCP), a related technology for the identification of bacterial cells. Purified genomic DNAs from six bacterial strains were labeled by nick translation with the fluorochrome Fluor-X, Cy3, or Cy5. The average size of the labeled fragments was ca. 5...

  7. Modeling bacterial chemotaxis inside a cell

    OpenAIRE

    Ouannes, Nesrine; Djedi, Noureddine; Luga, Hervé; Duthen, Yves

    2014-01-01

    This paper describes a bacterial system that reproduces a population of bacteria that behave by simulating the internal reactions of each bacterial cell. The chemotaxis network of a cell is modulated by a hybrid approach that uses an algebraic model for the receptor clusters activity and an ordinary differential equation for the adaptation dynamics. The experiments are defined in order to simulate bacterial growth in an environment where nutrients are regularly added to it. The results show a...

  8. Correlations Between Bacterial Ecology and Mobile DNA

    OpenAIRE

    Newton, Irene L. G.; Bordenstein, Seth R.

    2010-01-01

    Several factors can affect the density of mobile DNA in bacterial genomes including rates of exposure to novel gene pools, recombination, and reductive evolution. These traits are difficult to measure across a broad range of bacterial species, but the ecological niches occupied by an organism provide some indication of the relative magnitude of these forces. Here, by analyzing 384 bacterial genomes assigned to three ecological categories (obligate intracellular, facultative intracellular, and...

  9. Bacterial infections in patients with liver cirrhosis

    OpenAIRE

    Preveden Tomislav

    2015-01-01

    Introduction. Liver cirrhosis is characterized by a reduced defensive reaction to bacterial infections and patients with cirrhosis are at increased risk of developing infections, sepsis and death. The most common bacterial infections in these patients are spontaneous bacterial peritonitis, urinary tract infection, pneumonia, skin and soft tissue infection and bacteremia. The most common causes are Gram negative bacteria. The aim of this study was to determi...

  10. Effect of aerosolization on subsequent bacterial survival.

    OpenAIRE

    Walter, M V; Marthi, B; Fieland, V P; Ganio, L M

    1990-01-01

    To determine whether aerosolization could impair bacterial survival, Pseudomonas syringae and Erwinia herbicola were aerosolized in a greenhouse, the aerosol was sampled at various distances from the site of release by using all-glass impingers, and bacterial survival was followed in the impingers for 6 h. Bacterial survival subsequent to aerosolization of P. syringae and E. herbicola was not impaired 1 m from the site of release. P. syringae aerosolized at 3 to 15 m from the site of release ...

  11. Drag Reduction of Bacterial Cellulose Suspensions

    OpenAIRE

    Ogata, Satoshi; Numakawa, Tetsuya; Kubo, Takuya

    2010-01-01

    Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechani...

  12. Drag Reduction of Bacterial Cellulose Suspensions

    OpenAIRE

    Satoshi Ogata; Tetsuya Numakawa; Takuya Kubo

    2011-01-01

    Drag reduction due to bacterial cellulose suspensions with small environmental loading was investigated. Experiments were carried out by measuring the pressure drop in pipe flow. It was found that bacterial cellulose suspensions give rise to drag reduction in the turbulent flow range. We observed a maximum drag reduction ratio of 11% and found that it increased with the concentration of the bacterial cellulose suspension. However, the drag reduction effect decreased in the presence of mechani...

  13. Bioinformatic Comparison of Bacterial Secretomes

    Institute of Scientific and Technical Information of China (English)

    Catharine Song; Aseem Kumar; Mazen Saleh

    2009-01-01

    The rapid increasing number of completed bacterial genomes provides a good op-portunity to compare their proteomes. This study was undertaken to specifically compare and contrast their secretomes-the fraction of the proteome with pre-dicted N-terminal signal sequences, both type Ⅰ and type Ⅱ. A total of 176 theoreti-cal bacterial proteomes were examined using the ExProt program. Compared with the Gram-positives, the Gram-negative bacteria were found, on average, to con-tain a larger number of potential Sec-dependent sequences. In the Gram-negative bacteria but not in the others, there was a positive correlation between proteome size and secretome size, while there was no correlation between secretome size and pathogenicity. Within the Gram-negative bacteria, intracellular pathogens were found to have the smallest secretomes. However, the secretomes of certain bacte-ria did not fit into the observed pattern. Specifically, the secretome of Borrelia burgdoferi has an unusually large number of putative lipoproteins, and the signal peptides of mycoplasmas show closer sequence similarity to those of the Gram-negative bacteria. Our analysis also suggests that even for a theoretical minimal genome of 300 open reading frames, a fraction of this gene pool (up to a maximum of 20%) may code for proteins with Sec-dependent signal sequences.

  14. Bacterial mutagenicity assays: test methods.

    Science.gov (United States)

    Gatehouse, David

    2012-01-01

    The most widely used assays for detecting chemically induced gene mutations are those employing bacteria. The plate incorporation assay using various Salmonella typhimurium LT2 and E. coli WP2 strains is a short-term bacterial reverse mutation assay specifically designed to detect a wide range of chemical substances capable of causing DNA damage leading to gene mutations. The test is used worldwide as an initial screen to determine the mutagenic potential of new chemicals and drugs.The test uses several strains of S. typhimurium which carry different mutations in various genes of the histidine operon, and E. coli which carry the same AT base pair at the critical mutation site within the trpE gene. These mutations act as hot spots for mutagens that cause DNA damage via different mechanisms. When these auxotrophic bacterial strains are grown on a minimal media agar plates containing a trace of the required amino-acid (histidine or tryptophan), only those bacteria that revert to amino-acid independence (His(+) or Tryp(+)) will grow to form visible colonies. The number of spontaneously induced revertant colonies per plate is relatively constant. However, when a mutagen is added to the plate, the number of revertant colonies per plate is increased, usually in a dose-related manner.This chapter provides detailed procedures for performing the test in the presence and absence of a metabolic activation system (S9-mix), including advice on specific assay variations and any technical problems. PMID:22147566

  15. BACTERIAL DESEASES IN SEA FISH

    Directory of Open Access Journals (Sweden)

    Ivančica Strunjak-Perović

    1997-10-01

    Full Text Available With development of the fish culturing in the sea, the interest in their health also increased. The reason for this are diseases or rather mortality that occur in such controlled cultures and cause great economic losses. By growing large quantities of fish in rather small species, natural conditions are changed, so fish is more sensitive and prone to infection agents (viruses, bacteria, parasites. Besides, a large fish density in the cultural process accelerates spreading if the diseases, but also enables a better perception of them. In wild populations sick specimen very quickly become predator’s prey, witch makes it difficult to note any pathological changes in such fish. There are lots of articles on viral, bacterial and parasitic diseases nowdays, but this work deals exclusively with bacterial deseases that occur in the controlled sea cultures (vibriosis, furunculosis, pastherelosis, nocardiosis, mycobaceriosis, edwardsielosis, yersiniosis, deseases caused by bacteria of genera Flexibacter, Pseudomonas, Aeromonas, Streptococus and bacteria nephryithis. Yet, the knowledge of these deseases vary, depending on wether a fish species is being cultured for a longer period of time or is only being introduced in the controlled culture.

  16. Immunization by a bacterial aerosol.

    Science.gov (United States)

    Garcia-Contreras, Lucila; Wong, Yun-Ling; Muttil, Pavan; Padilla, Danielle; Sadoff, Jerry; Derousse, Jessica; Germishuizen, Willem Andreas; Goonesekera, Sunali; Elbert, Katharina; Bloom, Barry R; Miller, Rich; Fourie, P Bernard; Hickey, Anthony; Edwards, David

    2008-03-25

    By manufacturing a single-particle system in two particulate forms (i.e., micrometer size and nanometer size), we have designed a bacterial vaccine form that exhibits improved efficacy of immunization. Microstructural properties are adapted to alter dispersive and aerosol properties independently. Dried "nanomicroparticle" vaccines possess two axes of nanoscale dimensions and a third axis of micrometer dimension; the last one permits effective micrometer-like physical dispersion, and the former provides alignment of the principal nanodimension particle axes with the direction of airflow. Particles formed with this combination of nano- and micrometer-scale dimensions possess a greater ability to aerosolize than particles of standard spherical isotropic shape and of similar geometric diameter. Here, we demonstrate effective application of this biomaterial by using the live attenuated tuberculosis vaccine bacille Calmette-Guérin (BCG). Prepared as a spray-dried nanomicroparticle aerosol, BCG vaccine exhibited high-efficiency delivery and peripheral lung targeting capacity from a low-cost and technically simple delivery system. Aerosol delivery of the BCG nanomicroparticle to normal guinea pigs subsequently challenged with virulent Mycobacterium tuberculosis significantly reduced bacterial burden and lung pathology both relative to untreated animals and to control animals immunized with the standard parenteral BCG. PMID:18344320

  17. A stable live bacterial vaccine.

    Science.gov (United States)

    Kunda, Nitesh K; Wafula, Denis; Tram, Meilinn; Wu, Terry H; Muttil, Pavan

    2016-06-01

    Formulating vaccines into a dry form enhances its thermal stability. This is critical to prevent administering damaged and ineffective vaccines, and to reduce its final cost. A number of vaccines in the market as well as those being evaluated in the clinical setting are in a dry solid state; yet none of these vaccines have achieved long-term stability at high temperatures. We used spray-drying to formulate a recombinant live attenuated Listeria monocytogenes (Lm; expressing Francisella tularensis immune protective antigen pathogenicity island protein IglC) bacterial vaccine into a thermostable dry powder using various sugars and an amino acid. Lm powder vaccine showed minimal loss in viability when stored for more than a year at ambient room temperature (∼23°C) or for 180days at 40°C. High temperature viability was achieved by maintaining an inert atmosphere in the storage container and removing oxygen free radicals that damage bacterial membranes. Further, in vitro antigenicity was confirmed by infecting a dendritic cell line with cultures derived from spray dried Lm and detection of an intracellularly expressed protective antigen. A combination of stabilizing excipients, a cost effective one-step drying process, and appropriate storage conditions could provide a viable option for producing, storing and transporting heat-sensitive vaccines, especially in regions of the world that require them the most. PMID:27020530

  18. Bacterial Culture of Neonatal Sepsis

    Directory of Open Access Journals (Sweden)

    AH Movahedian

    2006-08-01

    Full Text Available Neonatal bacterial sepsis is one of the major cause of morbidity and mortality in neonates. This retrospective study was performed to determine the incidence of bacterial sepsis with focus on Gram negative organisms in neonates admitted at Beheshti Hospital in Kashan, during a 3-yr period, from September 2002 to September 2005. Blood culture was performed on all neonates with risk factors or signs of suggestive sepsis. Blood samples were cultured using brain heart infusion (BHI broth according to standard method. From the 1680 neonates 36% had positive blood culture for Pseudomans aeruginosa, 20.7% for Coagulase negative Staphylococci, and 17% for Klebsiella spp. Gram-negative organisms accounted for 72.1% of all positive cultures. The overall mortality rate was 19.8% (22 /111 of whom 63.6% (14 /22 were preterm. Pseudomona aeruginosa and Klebsiella spp. showed a high degree of resistance to commonly used antibiotics (ampicillin, gentamicin as well as third generation cephalosporins. Continued local surveillance studies are urged to monitor emerging antimicrobial resistance and to guide interventions to minimize its occurrence.

  19. Periodontal diseases as bacterial infection

    Directory of Open Access Journals (Sweden)

    A. Bascones Martínez

    2005-12-01

    Full Text Available The periodontal disease is conformed by a group of illnesses affecting the gums and dental support structures. They are caused by certain bacteria found in the bacterial plaque. These bacteria are essential to the onset of illness; however, there are predisposing factors in both the host and the microorganisms that will have an effect on the pathogenesis of the illness. Periodontopathogenic bacterial microbiota is needed, but by itself, it is not enough to cause the illness, requiring the presence of a susceptible host. These diseases have been classified as gingivitis, when limited to the gums, and periodontitis, when they spread to deeper tissues. Classification of periodontal disease has varied over the years.The one used in this work was approved at the International Workshop for a Classification of Periodontal Diseases and Conditions, held in 1999. This study is an overview of the different periodontal disease syndromes. Later, the systematic use of antibiotic treatment consisting of amoxicillin, amoxicillinclavulanic acid, and metronidazole as first line coadjuvant treatment of these illnesses will be reviewed.

  20. Isolation and biological control effects of cotton Verticilium wilt antagonist%棉花黄萎病拮抗菌的筛选及其生物防治效果

    Institute of Scientific and Technical Information of China (English)

    程凯; 江欢欢; 沈标; 徐阳春; 沈其荣; 杨兴明

    2011-01-01

    筛选到2株拮抗菌ZJ6和ZJ1并对其进行了鉴定,研究了其在盆钵试验中防治棉花黄萎病的效果,通过PCR的方法扩增了其含有的抗生素合成基因.结果如下:1)根据生理生化特性和16S rDNA序列分析,菌株ZJ6和ZJ1均鉴定为Bacillus subtilis.2)拮抗菌ZJ6和ZJ1与复合有机肥(氨基酸肥料:猪粪堆肥=1:1)混合施用(ANT-ZJ6,ANT-ZJ1)以及由ZJ6和ZJ1与复合有机肥二次发酵后制成的生物有机肥(BOF-ZJ6,BOF-ZJ1)对棉花黄萎病均有显著的防治作用,发病率降低39.8%~68.1%,病情指数降低56.3%~82.4%.其中ANT-ZJ6和BOF-ZJ6的防治效果达80%左右.与ANT相比,BOF的防治效果更好,特别是BOF-ZJ1比ANT-ZJ1的防治效果提高了20.8%.3)施用拮抗菌能显著改变根际土的微生物种群结构,施用BOF-ZJ6和BOF-ZJ1后,细菌数量分别增加了7.1和8.5倍,放线菌数量分别增加了11.7和32.6倍,而真菌数量分别下降了53.0%和68.2%,病原菌数量分别下降了 98.6%和98.5%.4)ZJ6含有bam、fenB、fenD、ituA、ituB、ituC、和ituD基因,它们分别是Bacillomycin、Fengycin和Iturin生物合成的相关基因;ZJ1含有fenB、fenD、sboA和QK基因,它们分别是Fengycin和Subtilisin生物合成的相关基因.总之,施用含有拮抗菌ZJ6和ZJ1的生物有机肥能有效防治棉花黄萎病.%Cotton Verticillium wilt is a soil-bom fungi disease, resulting in severe yield loss of cotton world wide.Compared with the rourine control on cotton Verticillium wilt, rhizobacteria-mediated biocontrol is a more effective alternative.Bacteria strains ZJ6 and ZJ1, which were antagonistic to Verticillium dahliae Kleb were screened and identified and their effects to control cotton Verticillium wilt were studied in pot experiments.Detection of antibiotic biosynthesis genes of the strains ZJ6 and ZJ1 were also done in this experiment.The results show that: 1 ) ZJ6 and ZJ1 are both identified as Bacillus subtilis according to their physiological and biochemical

  1. Identifying the fundamental units of bacterial diversity: A paradigm shift to incorporate ecology into bacterial systematics

    OpenAIRE

    Koeppel, Alexander; Perry, Elizabeth B.; Sikorski, Johannes; Krizanc, Danny; Warner, Andrew; Ward, David M.; Rooney, Alejandro P.; Brambilla, Evelyne; Connor, Nora; Ratcliff, Rodney M.; Nevo, Eviatar; Cohan, Frederick M

    2008-01-01

    The central questions of bacterial ecology and evolution require a method to consistently demarcate, from the vast and diverse set of bacterial cells within a natural community, the groups playing ecologically distinct roles (ecotypes). Because of a lack of theory-based guidelines, current methods in bacterial systematics fail to divide the bacterial domain of life into meaningful units of ecology and evolution. We introduce a sequence-based approach (“ecotype simulation”) to model the evolut...

  2. Efeito do emurchecimento e do inoculante bacteriano sobre a qualidade da silagem de capim Tanzânia e o desempenho de novilhas - DOI: 10.4025/actascianimsci.v28i4.600 Effect of wilting and inoculant on Tanzania grass silage quality and heifers performance - DOI: 10.4025/actascianimsci.v28i4.600

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Nussio

    2006-02-01

    Full Text Available O objetivo desse trabalho foi avaliar o efeito do tamanho de partícula, do teor de MS e do uso de inoculante bacteriano sobre as propriedades físicas e perdas por deterioração da silagem de capim Tanzânia. Também foram avaliados a ingestão de MS (IMS, o ganho de peso vivo (GPV e a conversão alimentar (CA de novilhas alimentadas com rações completas contendo essa silagem. A redução no tamanho da partícula não aumentou as densidades de matéria seca (DMS e de massa verde (DMV, não reduziu a porosidade e nem as perdas durante a ensilagem. O emurchecimento não reduziu a DMS devido ao maior teor de MS, ocasionando maiores perdas. Não houve efeito dos tratamentos sobre a IMS (2,36% PV, o GPV (1,03 kg animal-1 dia-1 e a CA (7,91 kg MS kg-1 GPV. Os procedimentos adotados na ensilagem de capim Tanzânia não foram eficientes em evitar perdas e não provocaram melhoria no desempenho dos animais.The objective was to study the e ffect of particle size, dry matter content and the addition of bacterial inoculant to the ensiling of Tanzania grass ( Panicum maximum, Jacq. cv. Tanzânia on the physical characteristics and losses occurred during silo unloading. Dry matter intake, live we ight gain and feed conversion of beef heifers fed TMR containing grass silage were measured. The small particle size in the forage did not increase either wet or DM silages bulk densities, did not reduce the porosity and did not change the unloading losses. The forage wilting was not enough to reduce the DM density due to the compensatory effect established by the higher DM content, which presented the highest losses. No significant differences were observed for treatments on animal DM intake (2.4%BW, body weight gain (1.03 kg animal-1 day-1 and feed conversion (7.91 kg MS kg-1 BWG. Treatments in the ensiling of Tanzania grass did not prevent unloading losses and did not improve animal performance.

  3. The two envelope membrane glycoproteins of Tomato spotted wilt virus show differences in lectin-binding properties and sensitivities to glycosidases

    International Nuclear Information System (INIS)

    Tomato spotted wilt virus (TSWV, Genus: Tospovirus, Family: Bunyaviridae) is a major constraint to the production of several different crops of agronomic and horticultural importance worldwide. The amino acid sequence of the two envelope membrane glycoproteins, designated as GN (N-terminal) and GC (C-terminal), of TSWV contain several tripeptide sequences, Asn-Xaa-Ser/Thr, suggesting that the proteins are N-glycosylated. In this study, the lectin-binding properties of the viral glycoproteins and their sensitivities to glycosidases were examined to obtain information on the nature of potential oligosaccharide moieties present on GN and GC. The viral proteins were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and probed by affinoblotting using a battery of biotinylated lectins with specificity to different oligosaccharide structures. GC showed strong binding with five mannose-binding lectins, four N-acetyllactosamine-binding lectins and one fucose-binding lectin. GN was resolved into two molecular masses and only the slow migrating form showed binding, albeit to a lesser extent than GC, with three of the five mannose-binding lectins. The N-acetyllactosamine- and fucose-specific lectins did not bind to either molecular mass form of GN. None of the galactose-, N-acetylgalactosamine-, or sialic acid-binding lectins tested showed binding specificity to GC or GN. Treatment of the denatured virions with endoglycosidase H and peptide:N-glycosidase F (PNGase F) resulted in a significant decrease in the binding of GC to high mannose- and N-acetyllactosamine-specific lectins. However, no such differences in lectin binding were apparent with GN. These results indicate the presence of N-linked oligosaccharides of high mannose- and complex-type on GC and possibly high mannose-type on GN. Differences in the extent of binding of the two envelope glycoproteins to different lectins suggest that GC is likely to be more heavily N-glycosylated than

  4. Bacterial interactions in dental biofilm.

    Science.gov (United States)

    Huang, Ruijie; Li, Mingyun; Gregory, Richard L

    2011-01-01

    Biofilms are masses of microorganisms that bind to and multiply on a solid surface, typically with a fluid bathing the microbes. The microorganisms that are not attached but are free floating in an aqueous environment are termed planktonic cells. Traditionally, microbiology research has addressed results from planktonic bacterial cells. However, many recent studies have indicated that biofilms are the preferred form of growth of most microbes and particularly those of a pathogenic nature. Biofilms on animal hosts have significantly increased resistance to various antimicrobials compared to planktonic cells. These microbial communities form microcolonies that interact with each other using very sophisticated communication methods (i.e., quorum-sensing). The development of unique microbiological tools to detect and assess the various biofilms around us is a tremendously important focus of research in many laboratories. In the present review, we discuss the major biofilm mechanisms and the interactions among oral bacteria. PMID:21778817

  5. Bacterial diseases of the skin.

    Science.gov (United States)

    Edlich, Richard F; Winters, Kathryne L; Britt, L D; Long, William B

    2005-01-01

    When considering common bacterial diseases of the skin, rather distinct clinical responses to a variety of bacterial infections have been identified. In these cases, it is the specific site of infection and the attendant inflammatory responses that provide the characteristic clinical picture. When the pyoderma extends just below the stratum corneum, it is called impetigo. Nonbullous impetigo is the most common pediatric skin infection. It usually starts in a traumatized area. The typical lesion begins as an erythematous papule, after which it becomes a unilocular vesicle. When the subcorneal vesicle becomes pustular, it ruptures and eventually becomes a yellow, golden crust that is a hallmark of the disease process. Bullous impetigo is a less common form of impetigo, accounting for fewer than 30% of all impetigo cases. It occurs in infants and is characterized by rapid progression of vesicles to the formation of bullae measuring larger than 5 mm in diameter in previously untraumatized skin. Treatment of nonbullous impetigo must include intervention against the pathogen as well as improvements in the hygiene and living conditions of the patient. A fundamental tenet is to debride the crust (scab) from the wound surface using poloxamer 188. If the lesions are not widespread, topical mupirocin is the treatment of choice. Treatment of bullous impetigo is similar, except that the local cleansing and topical antibiotic must be complemented by systemic antibiotics if there is evidence of disseminating infections. Ecthyma is usually a consequence of failure to treat effectively impetigo. The untreated infection extends deep into the tissue in shallow ulcerations that often heal without scar. Treatment for ecthyma usually requires systemic antibiotics against either staphylococcus or streptococcus. Folliculitis is a pyoderma located within a hair follicle, secondary to follicular occlusion by keratin, overhydration, or either bacterial or fungal infection. Folliculitis may

  6. Unexpected versatility in bacterial riboswitches.

    Science.gov (United States)

    Mellin, J R; Cossart, Pascale

    2015-03-01

    Bacterial riboswitches are elements present in the 5'-untranslated regions (UTRs) of mRNA molecules that bind to ligands and regulate the expression of downstream genes. Riboswitches typically regulate the expression of protein-coding genes. However, mechanisms of riboswitch-mediated regulation have recently been shown to be more diverse than originally thought, with reports showing that riboswitches can regulate the expression of noncoding RNAs and control the access of proteins, such as transcription termination factor Rho and RNase E, to a nascent RNA. Riboswitches are also increasingly used in biotechnology, with advances in the engineering of synthetic riboswitches and the development of riboswitch-based sensors. In this review we address the emerging roles and mechanisms of riboswitch-mediated regulation in natura and recent progress in the development of riboswitch-based technology. PMID:25708284

  7. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.;

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...... to the survival of biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy and they can be treated by chronic suppressive therapy. A promising strategy may be the use of enzymes that can dissolve the biofilm matrix (e.g. DNase and alginate lyase) as well as quorum...

  8. Autoproteolytic Activation of Bacterial Toxins

    Directory of Open Access Journals (Sweden)

    Aimee Shen

    2010-05-01

    Full Text Available Protease domains within toxins typically act as the primary effector domain within target cells. By contrast, the primary function of the cysteine protease domain (CPD in Multifunctional Autoprocessing RTX-like (MARTX and Clostridium sp. glucosylating toxin families is to proteolytically cleave the toxin and release its cognate effector domains. The CPD becomes activated upon binding to the eukaryotic-specific small molecule, inositol hexakisphosphate (InsP6, which is found abundantly in the eukaryotic cytosol. This property allows the CPD to spatially and temporally regulate toxin activation, making it a prime candidate for developing anti-toxin therapeutics. In this review, we summarize recent findings related to defining the regulation of toxin function by the CPD and the development of inhibitors to prevent CPD-mediated activation of bacterial toxins.

  9. Bacterial biofilms: prokaryotic adventures in multicellularity

    DEFF Research Database (Denmark)

    Webb, J.S.; Givskov, Michael Christian; Kjelleberg, S.

    2003-01-01

    The development of bacterial biofilms includes both the initial social behavior of undifferentiated cells, as well as cell death and differentiation in the mature biofilm, and displays several striking similarities with higher organisms. Recent advances in the field provide new insight into...... differentiation and cell death events in bacterial biofilm development and propose that biofilms have an unexpected level of multicellularity....

  10. Recent advances in bacterial heme protein biochemistry

    OpenAIRE

    Mayfield, Jeffery A.; Dehner, Carolyn A.; Dubois, Jennifer L.

    2011-01-01

    Recent progress in genetics, fed by the burst in genome sequence data, has led to the identification of a host of novel bacterial heme proteins that are now being characterized in structural and mechanistic terms. The following short review highlights very recent work with bacterial heme proteins involved in the uptake, biosynthesis, degradation, and use of heme in respiration and sensing.

  11. Plant Natural Products Targeting Bacterial Virulence Factors.

    Science.gov (United States)

    Silva, Laura Nunes; Zimmer, Karine Rigon; Macedo, Alexandre José; Trentin, Danielle Silva

    2016-08-24

    Decreased antimicrobial efficiency has become a global public health issue. The paucity of new antibacterial drugs is evident, and the arsenal against infectious diseases needs to be improved urgently. The selection of plants as a source of prototype compounds is appropriate, since plant species naturally produce a wide range of secondary metabolites that act as a chemical line of defense against microorganisms in the environment. Although traditional approaches to combat microbial infections remain effective, targeting microbial virulence rather than survival seems to be an exciting strategy, since the modulation of virulence factors might lead to a milder evolutionary pressure for the development of resistance. Additionally, anti-infective chemotherapies may be successfully achieved by combining antivirulence and conventional antimicrobials, extending the lifespan of these drugs. This review presents an updated discussion of natural compounds isolated from plants with chemically characterized structures and activity against the major bacterial virulence factors: quorum sensing, bacterial biofilms, bacterial motility, bacterial toxins, bacterial pigments, bacterial enzymes, and bacterial surfactants. Moreover, a critical analysis of the most promising virulence factors is presented, highlighting their potential as targets to attenuate bacterial virulence. The ongoing progress in the field of antivirulence therapy may therefore help to translate this promising concept into real intervention strategies in clinical areas. PMID:27437994

  12. Bacterial cell division proteins as antibiotic targets

    NARCIS (Netherlands)

    T. den Blaauwen; J.M. Andreu; O. Monasterio

    2014-01-01

    Proteins involved in bacterial cell division often do not have a counterpart in eukaryotic cells and they are essential for the survival of the bacteria. The genetic accessibility of many bacterial species in combination with the Green Fluorescence Protein revolution to study localization of protein

  13. Immunity to bacterial infection in the chicken.

    Science.gov (United States)

    Wigley, Paul

    2013-11-01

    Bacterial infections remain important to the poultry industry both in terms of animal and public health, the latter due to the importance of poultry as a source of foodborne bacterial zoonoses such as Salmonella and Campylobacter. As such, much focus of research to the immune response to bacterial infection has been to Salmonella. In this review we will focus on how research on avian salmonellosis has developed our understanding of immunity to bacteria in the chicken from understanding the role of TLRs in recognition of bacterial pathogens, through the role of heterophils, macrophages and γδ lymphocytes in innate immunity and activation of adaptive responses to the role of cellular and humoral immunity in immune clearance and protection. What is known of the immune response to other bacterial infections and in particular infections that have emerged recently as major problems in poultry production including Campylobacter jejuni, Avian Pathogenic Escherichia coli, Ornithobacterium rhinotracheale and Clostridium perfringens are discussed. PMID:23648643

  14. Structural Biology of Bacterial RNA Polymerase

    Directory of Open Access Journals (Sweden)

    Katsuhiko S. Murakami

    2015-05-01

    Full Text Available Since its discovery and characterization in the early 1960s (Hurwitz, J. The discovery of RNA polymerase. J. Biol. Chem. 2005, 280, 42477–42485, an enormous amount of biochemical, biophysical and genetic data has been collected on bacterial RNA polymerase (RNAP. In the late 1990s, structural information pertaining to bacterial RNAP has emerged that provided unprecedented insights into the function and mechanism of RNA transcription. In this review, I list all structures related to bacterial RNAP (as determined by X-ray crystallography and NMR methods available from the Protein Data Bank, describe their contributions to bacterial transcription research and discuss the role that small molecules play in inhibiting bacterial RNA transcription.

  15. Bacterial microleakage of aged adhesive restorations

    Directory of Open Access Journals (Sweden)

    Nevin Cobanoglu

    2015-01-01

    Full Text Available Objective: The aim of this study was to investigate the marginal bacterial leakage of two self-etch adhesive systems after long-term water storage. Materials and Methods: Class V cavities were prepared on the buccal and lingual surfaces of extracted premolar teeth. After the sterilization of the teeth, four cavities were not restored for control purposes, whereas the other teeth were divided into two groups (n = 16 cavities each: Clearfil Protect Bond (CPB, Clearfil SE Bond (CSE. After the application of the bonding agent, cavities were restored with a composite resin. Then, the teeth were thermo cycled, stored in saline solution for 6 months and put into a broth culture of Streptococcus mutans. The teeth were fixed, sectioned and stained using the Gram-Colour modified method. The stained sections were then evaluated under a light microscope. The bacterial leakage was scored as: 0 - absence of stained bacteria, 1 - bacterial staining along the cavity walls, 2 - bacterial staining within the cut dentinal tubules. The data were analysed using the Kruskal-Wallis and Mann-Whitney U-test (P = 0.05. Results: The bacterial staining was detected within the cut dentinal tubules in all control cavities, in three cavities in the CSE group and one cavity in the CPB group. There were no observed statistically significant differences between the bacterial penetrations of the two bonding systems (P > 0.05. Conclusion: Both bonding systems provided acceptable prevention of marginal bacterial leakage after long-term water storage.

  16. Genetic Analysis on Effects of Sea Island Cotton Fusarium wilt on Yield Factor and the Correlation Indexes%枯萎病对海岛棉产量因素及相关指标的遗传分析

    Institute of Scientific and Technical Information of China (English)

    陈磊; 李吉琴; 刘艳; 陈全家; 顾爱星; 马顺尧; 柴颜军; 郑炜佳; 曲延英

    2012-01-01

    以海岛棉抗病材料06-146和感病材料新海14的杂交群体为材料,考察了该群体的亲本、F1以及F2~F2:5代家系,借助方差分析得到了枯萎病对其农艺性状和产量相关性状的影响.结果显示,随着病级的增加,株高、果枝数等性状低于对照,并且与产量相关性状下降明显.表现出了海岛棉枯萎病的致萎缩及减产的危害.运用相关分析和主成分分析,考察了病级与海岛棉产量因子之间的关系.结果显示,海岛棉产量与病级呈显著的负相关,同时与果枝数和株高呈负相关,也反应出枯萎病对海岛棉具有减产的作用.%The hybrid group of the disease-resistant sea island cotton 06-146 and the feeling sick sea island cotton Xinhail4 was studied to investigate the parents,the descendant of its F1and F2 ?F2:5 descents,the effect of Fusarium wilt of sea island cotton on the agronomic characters and yield was achieved by variance analysis. The result showed that the agronomic characters of the plant height and branch number were lower than those of the control group with the increase of the grade of disease. Also the characters related to cotton yield were significantly reduced, which showed the harmfulness of Fusarium wilt of sea island cotton. The correlations between the yield factors of the sea island cotton and degrade of diseases were obtained by principal component analysis. The result showed that the yield had negative correlation with the grade of the disease and the number of the cotton boll and the plant height. This also reflected that crop failure of sea island cotton could be caused by the cotton Fusarium wilt.

  17. 番茄枯萎病病原菌鉴定与拮抗菌筛选%Identification of Pathogen Causing Tomato Fusarium Wilt and Screening of Its Antagonistic Microorganisms

    Institute of Scientific and Technical Information of China (English)

    崔萍; 安慧; 张楠; 李芳慧

    2013-01-01

    The pathogen was isolated from the root of the Fusarium wilt infected tomato by tissue isolating method,and identified as Fusarium oxysporum according to the morphology,pathogenicity and sequence analysis of the internal transcribed space region of the ribosomal DNA (ITS).The microbial quantity of the Fusarium wilt infected,healthy tomato root rizosphere substrates,and non-rizosphere field soils and the mountain soils were studied.From the soils,77 isolates were got and had certain inhibiting action on tomato Fusarium wilt by dual culture and 24 isolates with higher bio-control effect were obtained through further screening.The results also showed that the mountain soil had less biomass,but more antagonistic strains,and the fungus A6,A29,A9,A31,A44 and A28,which had the higher antagonistic effect,were isolated.%应用组织分离法从发病番茄根部分离番茄枯萎病病原菌并进行致病性测定,根据菌体形态特征、ITS序列同源性分析将病原菌鉴定为镰刀菌属尖孢镰刀菌(Fusarium oxysporum).探讨了发病及健康番茄根际栽培基质、大田土及山地贫瘠土壤的微生物数量,采用平板对峙培养法初筛得到77个对番茄枯萎病病原菌有拮抗作用的分离物,进一步复筛得到24个拮抗性能较为稳定的分离物,其中来自山地土的真菌A6、A29、A9、A31、A44、A28拮抗作用较强.山地贫瘠土壤尽管微生物总量较少,但是分离获得的拮抗菌数量最多.

  18. Detection of Intracellular Bacterial Communities in Human Urinary Tract Infection

    OpenAIRE

    Opal, Steven M

    2007-01-01

    Steven Opal reviews the phenomenon of bacterial communities and discusses the role played by bacterial communication and cooperation in host-pathogen interactions, particularly in urinary tract infection.

  19. Asymptomatic Bacteriuria and Bacterial Interference.

    Science.gov (United States)

    Nicolle, Lindsay E

    2015-10-01

    Asymptomatic bacteriuria is very common. In healthy women, asymptomatic bacteriuria increases with age, from asymptomatic bacteriuria, irrespective of age or gender. The prevalence is very high in residents of long-term-care facilities, from 25% to 50% of women and 15% to 40% of men. Escherichia coli is the most frequent organism isolated, but a wide variety of other organisms may occur. Bacteriuria may be transient or persist for a prolonged period. Pregnant women with asymptomatic bacteriuria identified in early pregnancy and who are untreated have a risk of pyelonephritis later in pregnancy of 20% to 30%. Bacteremia is frequent in bacteriuric subjects following mucosal trauma with bleeding, with 5% to 10% of patients developing severe sepsis or septic shock. These two groups with clear evidence of negative outcomes should be screened for bacteriuria and appropriately treated. Asymptomatic bacteriuria in other populations is benign and screening and treatment are not indicated. Antimicrobial treatment has no benefits but is associated with negative outcomes including reinfection with antimicrobial resistant organisms and a short-term increased frequency of symptomatic infection post-treatment. The observation of increased symptomatic infection post-treatment, however, has led to active investigation of bacterial interference as a strategy to prevent symptomatic episodes in selected high risk patients. PMID:26542046

  20. Radionuclide scintigraphy of bacterial nephritis

    International Nuclear Information System (INIS)

    Pyelonephritis is a leading cause of renal failure and is expected to cost as much as three billion dollars in 1984. The diagnosis of urinary tract infection is usually not difficult. However, localization of the infection within the renal parenchyma as opposed to the collecting system is much more difficult. Flank pain, fever, bacteiuria and evidence of parenchymal involvement by intravenous urography may be absent or unrecognized particularly in the infant. Ultrasound and Nuclear Medicine are advocated as better methods to define parenchymal involvement. Such definition is important in the consideration of treatment since parenchymal involvement of the kidney carries a much more ominous potential outcome than infection restricted to within the collecting system. 38 children with a clinical diagnosis of urinary tract infection were studied. 26 of the patients demonstrated abnormal renal parenchymal findings with Gallium-67 Citrate or Tc-99m Glucoheptonate scintigraphy. Intravenous urography was notably ineffective with only 5 of the 20 interpreted as abnormal due to parenchymal disease or decreased function. 11 were entirely normal while only 5 demonstrated scars or hydronephrosis. Only 10 of 17 patients demonstrated intranvesicoureteral reflux on x-ray or nuclear cystography. Ultrasound depicted 6 of 20 patients as having parenchymal abnormalities. Seven were normal. Nonspecific findings such as dilitation of the renal pelvis or renal enlargement was noted in 11 of the 20 patients. Radionuclide Scintigraphy is the most efficacious modality to detect since acute bacterial nephritis

  1. Rheumatoid arthritis and bacterial infections

    Directory of Open Access Journals (Sweden)

    N L Prokopjeva

    2008-01-01

    Full Text Available To study features of bacterial infections course in pts with rheumatoid arthritis (RA and changes of laboratory measures after focus of infection sanation. Material and methods. 46 pts with definite rheumatoid arthritis were examined at the time of comorbid infection (Cl detection and after infection focus sanation. Bacteriological test with evaluation of flora sensitivity to antibiotics by disco-diffusion method was performed at baseline and after the course of antibacterial therapy to assess its efficacy. Hemogram, serum fibrinogen, rheumatoid factor, circulating immune complexes (CIC, C-reactive protein levels were assessed. Serum interleukin (IL 1(3, IL6 and neopterin concentrations were examined by immune-enzyme assay in a part of pts. Typical clinical features of Cl were present in only 28 (60,9% pts. 13 (28,3% pts had fever, 12 (26,0% — leukocytosis, 15 (32,6% — changes of leucocyte populations. Some laboratory measures (thrombocytes, fibrinogen, CIC, neopterin levels significantly decreased (p<0,05 after infection focus sanation without correction of disease modifying therapy. Cl quite often develop as asymptomatic processes most often in pts with high activity and can induce disturbances promoting appearance of endothelial dysfunction, atherothrombosis and reduction of life duration. So timely detection and proper sanation of infection focuses should be performed in pts with RA

  2. BACTERIAL FLORA IN DIABETIC ULCER

    Directory of Open Access Journals (Sweden)

    Anitha Lavanya

    2015-04-01

    Full Text Available BACKGROUND : Diabetic foot infections are one of the most feared complications of diabetes. This study was undertaken to determine the common etiological agents of diabetic foot infections and their in vitro antibiotic susceptibility. METHODS : A prospective study was p erformed over a period of two years in a tertiary care hospital. The aerobic and anaerobic bacterial agents were isolated and their antibiotic susceptibility pattern was determined . RESULTS : One hundred patients with Diabetic ulcer were studied, of which 6 5 were males and 35 were females. Majority of patients were in the age group of 51 to 60 years (37% and polymicrobial etiology was 64 % and monomicrobial etiology was 36%. A total of 187 organisms were isolated of which 165 were aerobic and 22 were anaero bic. Most frequently isolated aerobic organisms were Pseudomonas Sp., Klebsiella Sp., E coli Sp., and Staphylococcus aureus. The common anaerobic organisms isolated were Peptostreptococcus Sp. And Bacterioids Sp. CONCLUSION : High prevalence of multi - drug r esistant pathogens was observed. Amikacin, Imipenem were active against gram - negative bacilli, while vancomycin was found to be active against gram - positive bacteria.

  3. Spontaneous Bacterial Peritonitis in Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Dalip Gupta

    2013-11-01

    Full Text Available Hypothyroidism is an uncommon cause of ascites. Here we describe a case of a 75 year-old female patient with spontaneous bacterial peritonitis and subclinical hypothyroidism that resolved with thyroid replacement and antibiotic therapy respectively. Ascitic fluid analysis revealed a gram-positive bacterium on gram staining. A review of the literature revealed just one other reported case of myxoedema ascites with concomitant spontaneous bacterial peritonitis and no case has till been reported of spontaneous bacterial peritonitis in subclinical hypothyroidism.

  4. Biochemistry of Bacterial Multidrug Efflux Pumps

    Directory of Open Access Journals (Sweden)

    Sanath Kumar

    2012-04-01

    Full Text Available Bacterial pathogens that are multi-drug resistant compromise the effectiveness of treatment when they are the causative agents of infectious disease. These multi-drug resistance mechanisms allow bacteria to survive in the presence of clinically useful antimicrobial agents, thus reducing the efficacy of chemotherapy towards infectious disease. Importantly, active multi-drug efflux is a major mechanism for bacterial pathogen drug resistance. Therefore, because of their overwhelming presence in bacterial pathogens, these active multi-drug efflux mechanisms remain a major area of intense study, so that ultimately measures may be discovered to inhibit these active multi-drug efflux pumps.

  5. New perspectives on bacterial ferredoxin evolution

    Science.gov (United States)

    George, D. G.; Hunt, L. T.; Yeh, L.-S. L.; Barker, W. C.

    1985-01-01

    Ferredoxins are low-molecular-weight, nonheme, iron proteins which function as electron carriers in a wide variety of electron transport chains. Howard et al. (1983) have suggested that the amino end of Azotobacter vinelandii ferredoxin shows a greater similarity to the carboxyl end of ferredoxin from Chromatium vinosum and that their half-chain sequences are homologous when the half-chains of either species are considered in inverse order. Examination of this proposition has made it necessary to reevaluate previous conclusions concerning the evolution of bacterial ferredoxin. Attention is given to the properties of the bacterial ferredoxin sequences, and the evolution of the bacterial ferredoxins.

  6. Tobacco use increases susceptibility to bacterial infection

    Directory of Open Access Journals (Sweden)

    Demuth Donald R

    2008-12-01

    Full Text Available Abstract Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.

  7. Studies of Fresh or Wilted Sainfoin Silage with Selected Additives%添加剂对红豆草鲜贮或晾晒后青贮品质的影响

    Institute of Scientific and Technical Information of China (English)

    刘玲; 陈新; 许庆方; 玉柱; 王保平; 孙启忠; 石永红; 刘建宁

    2011-01-01

    Effects of different additives on fresh or wilted sainfoin silage were studied to provide scientific guidelines of sainfoin silage production. Sainfoin forages were divided into fresh and wilted groups. Each group was treated with formic acid (6 mL ? Kg-1) and sucrose (2%) before ensiling, respectively. Silage was sampled and analyzed after storage 360 d. Results showed that wilting and formic acid improved silage fermentation quality. Acetic acid (P<0. 05) and ammonia nitrogen content of silage (P<0. 01) were significantly reduced, and dry matter content of silage was significantly increased (P<0. 01) in wilted group compared with the fresh group. The pH value, acetic acid content, ammonia nitrogen content (P<0. 01) , neutral detergents fiber and acid detergent fiber content of silage were significantly reduced (P<0. 05) , and lactic acid content of silage was significantly increased (P<0. 01) in the formic acid treatment compared with control (no additives). Nitrate content of silage decreased while nitrite content of silage increased after ensiling. These results indicated that formic acid can improve the fermentative quality of sainfoin silage.%探讨不同含水量和添加剂对红豆草(Onobrychis viciae olia Scop.)青贮品质的影响,为红豆草青贮饲料的调制提供科学依据.将红豆草分为2组,其中1组以鲜样进行青贮,分别设对照、添加甲酸(6 mL· kg-1)和蔗糖(2%)处理;另1组晾晒后进行同样的处理;袋装密封青贮360 d后取样分析.结果表明:晾晒处理能够改善红豆草青贮饲料的发酵品质,晾晒后青贮可以显著降低乙酸含量(P<0.05),极显著地降低青贮饲料中氨态氮含量(P<0.01).添加甲酸能够极显著降低红豆草青贮饲料的pH、乙酸和氨态氮含量(P<0.01),提高乳酸的生成量(P<0.01).晾晒可以极显著地增加青贮饲料中干物质(DM)含量(P<0.01);添加甲酸可以显著降低青贮饲料中的中性洗涤纤

  8. 不同作物套栽对枯草芽孢杆菌控制石榴枯萎病效果的影响%Control of Pomegranate Wilt by Combination of Bacillus subtilis and Vegetation Intercropping

    Institute of Scientific and Technical Information of China (English)

    汤东生; 蒋其军; 毛忠顺; 潘俊; 陆进; 何霞红

    2012-01-01

    The present study was carried out to detect the inhibition activity of Bacillus subtilis against pomegranate wilt pathogen Ceratocystis fimbriata in laboratory.Colonization dynamics of B.subtilis in rhizosphere of pomegranate(Punica granatum),tomato(Lycopersicum esculentum),soybean(Glycine max),rape(Brassica chinensis),coriander(Coriandrum sativum),green Chinese onion(Allium fistulosum var.giganteum) and garlic(Allium sativum) plants were investigated.Control efficiency of B.subtilis in combination with intercropping the 6 vegetation on pomegranate wilt in pot experiments were evaluated as well.Results showed that the strain of B.subtilis strongly restrained colony growth of C.fimbriata.Colonization capacity of B.subtilis in rhizosphere of pomegranate and other 6 plants was significantly different.Rhizosphere of L.esculentum,A.fistulosum var.giganteum and A.sativum could offer feasible environment for B.subtilis multiplication,whereas P.granatum could not.B.subtilis application in combination with vegetation intercropping of tomato,green chinese onion and garlic plants obviously reduced the disease index of pomegranate wilt,with control efficiency of 78.14%,80.99% and 78.91%,respectively.The results indicated that B.subtilis in combination with vegetation intercropping of tomato,green Chinese onion and garlic plants is of great potential for pomegranate wilt control in field.%本文室内测定了枯草芽孢杆菌Bacillus subtilis对石榴枯萎病菌Ceratocystis fimbriata的抑菌作用,检测其在石榴Punica granatum、番茄Lycopersicum esculentum、大豆Glycine max、青菜Brassica chinensis、芫荽Coriandrum sativum、大葱Allium fistulosum var. giganteum和大蒜Allium sativum根际的定殖动态及其结合作物套栽对石榴枯萎病的盆栽控制效果。结果表明,芽孢杆菌在不同供试植物根际的定殖能力差异大,在石榴根际的定殖力弱,在番茄、大葱和大蒜根际的定殖力强;作物套

  9. 不同砧木嫁接对西瓜抗生理性凋萎症的作用机理研究%Effect mechanisms of different grafting rootstocks on physiological wilt disease of watermelon

    Institute of Scientific and Technical Information of China (English)

    韦志扬; 覃泽林; 韦莉萍; 韦昌联; 麻小燕; 温国泉; 何毅

    2013-01-01

    [目的]探明不同砧木嫁接对西瓜抗生理性凋萎症的作用机理,为抗性砧木筛选和育种提供理论依据.[方法]选用葫芦、南瓜、冬瓜、野生西瓜等12个砧木与广西三号无籽西瓜进行嫁接试验、田间栽培试验,测定不同嫁接组合对西瓜生长后期叶片生理生化指标的影响.[结果]不同的嫁接组合中,以白籽南瓜、广西本地葫芦、杂交葫芦、伙伴野生西瓜、日本南瓜、大蒲瓜、超丰F1作砧木西瓜生理性凋萎症发病率较低,为0~6.00%,最低的为白籽南瓜.发病率低的组合,其叶片叶绿素a、叶绿素b、总叶绿素含量和POD活性、SOD活性、Pro含量均极显著高于对照,MDA含量则显著低于对照.[结论]日本南瓜、广西本地葫芦、杂交葫芦、伙伴野生西瓜对西瓜生理性凋萎症抗性较强,可在生产上示范应用.%Abstract:[Objective]The experiment was conducted to study the effect mechanisms of different rootstocks on physiological wilt disease of watermelon in order to provide theoretical foundation for resistant rootstock screening and watermelon breeding.[Method]Twelve different rootstocks of Lagenaria siceraria,squash,Benincasa and wild Citrullus vulgaris were selected to undergo the grafting test and filed cultivation test with seedless watermelon Guangxi 3.Physiological and biochemical indexes of watermelon leaves of different grafting combinations at later stage were determined.[Result]The watermelon grafted with rootstocks of white seed pumpkin,Guangxi local cucurbit,cross cucurbit,Huoban wild watermelon,Japanese pumpkin,large white flowered gourd,and Chaofeng F1 generation showed low incidence rate of physiological wilt disease.The incidence rate was in 0-6.00%.The incidence rate of physiological wilt disease was the lowest when white seed pumpkin was used as rootstock.The chlorophyll a content,chlorophyll b content,total chlorophyll content,POD and SOD activity and free praline content were all

  10. Trichoderma harzianum L1 as a potential source for lytic enzymes and elicitor of defense responses in chickpea (Cicer arietinum L. against wilt disease caused by Fusarium oxysporum f. sp. ciceri.

    Directory of Open Access Journals (Sweden)

    Sreeramulu K

    2009-01-01

    Full Text Available The effect of some natural lignocellulosic substances on the production of ß-glucanase, chitinase, protease and xylanase from Trichoderma harzianum L1 has been studied under solid state fermentation conditions. Maximum activities of all these enzymes were observed in the fermentation medium containing the mixture of 1% rice bran, neem cake and 0.1% crab shell powder. The induction of plant defense response was investigated by inoculating the roots of chickpea cv JG62 with the biocontrol agent, T. harzianum L1. A root extract of chickpea inoculated with T. harzianum L1 showed increased activities of phenylalanine ammonia lyase and polyphenol oxidase, as well as induction of new trypsin and chymotrypsin inhibitors. The Fusarium oxysporum protease-2 was inhibited completely by root extract of chickpea inoculated with T. harzianum L1 and showed maximum resistance to rotting of roots caused by wilt disease

  11. Bacterial diversity associated with freshwater zooplankton

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Dziallas, Claudia; Tang, Kam W.

    2009-01-01

    Bacterial community compositions (BCC) associated with the cladoceran Bosmina coregoni and the cyclopoid copepod Thermocyclops oithonoides in oligotrophic Lake Stechlin versus eutrophic Lake Dagow (northeastern Germany) were compared using molecular techniques. We also transplanted the zooplankton...

  12. Formation and dissolution of bacterial colonies

    Science.gov (United States)

    Weber, Christoph A.; Lin, Yen Ting; Biais, Nicolas; Zaburdaev, Vasily

    2015-09-01

    Many organisms form colonies for a transient period of time to withstand environmental pressure. Bacterial biofilms are a prototypical example of such behavior. Despite significant interest across disciplines, physical mechanisms governing the formation and dissolution of bacterial colonies are still poorly understood. Starting from a kinetic description of motile and interacting cells we derive a hydrodynamic equation for their density on a surface, where most of the kinetic coefficients are estimated from experimental data for N. gonorrhoeae bacteria. We use it to describe the formation of multiple colonies with sizes consistent with experimental observations. Finally, we show how the changes in the cell-to-cell interactions lead to the dissolution of the bacterial colonies. The successful application of kinetic theory to a complex far from equilibrium system such as formation and dissolution of living bacterial colonies potentially paves the way for the physical quantification of the initial stages of biofilm formation.

  13. Bacterial strategies of resistance to antimicrobial peptides.

    Science.gov (United States)

    Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

    2016-05-26

    Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. PMID:27160595

  14. Antibiotics promote aggregation within aquatic bacterial communities

    Directory of Open Access Journals (Sweden)

    ManuelaCoci

    2014-07-01

    These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of the effects of AB.

  15. Bacterial chromatin: converging views at different scales.

    Science.gov (United States)

    Dame, Remus T; Tark-Dame, Mariliis

    2016-06-01

    Bacterial genomes are functionally organized and compactly folded into a structure referred to as bacterial chromatin or the nucleoid. An important role in genome folding is attributed to Nucleoid-Associated Proteins, also referred to as bacterial chromatin proteins. Although a lot of molecular insight in the mechanisms of operation of these proteins has been generated in the test tube, knowledge on genome organization in the cellular context is still lagging behind severely. Here, we discuss important advances in the understanding of three-dimensional genome organization due to the application of Chromosome Conformation Capture and super-resolution microscopy techniques. We focus on bacterial chromatin proteins whose proposed role in genome organization is supported by these approaches. Moreover, we discuss recent insights into the interrelationship between genome organization and genome activity/stability in bacteria. PMID:26942688

  16. Vaccination against salmonid bacterial kidney disease

    Science.gov (United States)

    Bacterial kidney disease (BKD) of salmonid fishes, caused by Renibacterium salmoninarum, has presented challenges for development of effective vaccines, despite several decades of research. The only vaccine against BKD that is commercially licensed is an injectable preparation containing live cells ...

  17. Bacterial Infections - Multiple Languages: MedlinePlus

    Science.gov (United States)

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Bacterial Infections URL of this page: https://medlineplus.gov/languages/bacterialinfections.html Other topics A-Z A B ...

  18. Bacterial volatiles promote growth in Arabidopsis

    OpenAIRE

    Ryu, Choong-Min; Mohamed A. Farag; Hu, Chia-Hui; Reddy, Munagala S.; Wei, Han-Xun; Paré, Paul W.; Kloepper, Joseph W.

    2003-01-01

    Several chemical changes in soil are associated with plant growth-promoting rhizobacteria (PGPR). Some bacterial strains directly regulate plant physiology by mimicking synthesis of plant hormones, whereas others increase mineral and nitrogen availability in the soil as a way to augment growth. Identification of bacterial chemical messengers that trigger growth promotion has been limited in part by the understanding of how plants respond to external stimuli. With an increasing appreciation of...

  19. The Bacterial Microflora of Fish, Revised

    OpenAIRE

    Austin, B.

    2006-01-01

    The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen) of healthy fish may contain bacteria, but there is debate about whether or not muscle is actually sterile. Using traditional culture-dependent techniques, the numbers and taxonomic composition of the bacterial populations generally reflect those of the surrounding water. More modern...

  20. Bacterial biogeography of the human digestive tract

    OpenAIRE

    Stearns, Jennifer C.; Michael D. J. Lynch; Senadheera, Dilani B.; Howard C. Tenenbaum; Michael B. Goldberg; Cvitkovitch, Dennis G.; Kenneth Croitoru; Gabriel Moreno-Hagelsieb; Neufeld, Josh D.

    2011-01-01

    We present bacterial biogeography as sampled from the human gastrointestinal tract of four healthy subjects. This study generated >32 million paired-end sequences of bacterial 16S rRNA genes (V3 region) representing >95,000 unique operational taxonomic units (OTUs; 97% similarity clusters), with >99% Good's coverage for all samples. The highest OTU richness and phylogenetic diversity was found in the mouth samples. The microbial communities of multiple biopsy sites within the colon were highl...