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Sample records for bacterial wilt

  1. Selection of bacterial wilt-resistant tomato through tissue culture.

    Science.gov (United States)

    Toyoda, H; Shimizu, K; Chatani, K; Kita, N; Matsuda, Y; Ouchi, S

    1989-06-01

    Bacterial wilt-resistant plants were obtained using a tomato tissue culture system. A virulent strain ofPseudomonas solanacearum secreted some toxic substances into the culture medium. Leaf explant-derived callus tissues which were resistant to these toxic substances in the culture filtrate were selectedin vitro and regenerated into plants. These plants expressed bacterial wilt resistance at the early infection stage to suppress or delay the growth of the inoculated bacteria. On the other hand, complete resistance was obtained in self-pollinated progeny of regenerants derived from non-selected callus tissues. These plants showed a high resistance when inoculated with this strain, and were also resistant when planted in a field infested with a different strain of the pathogen.

  2. Endophytic Bacteria as Biocontrol Agents of Tomato Bacterial Wilt Disease

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    Arika Purnawati

    2014-01-01

    Full Text Available Ralstonia solanacearum is a tomato pathogen causing wilt disease which can lose crop production up to 100%. This problem also has economical impact to Indonesia, though controlling this pathogen has been donebefore. Biological control using endophytic bacteria is one of alternative control methods to support agriculture sustainability. The objective of these experiments are isolating endophytic bacteria taken from healthy tomato stems and root as well as investigating patogens as biocontrol agents of tomato bacterial wilt disease. Among 10 isolates found, only Ps1 and Ps8 can inhibit R. solanacearum based on antagonistic test in vitro using seed coat method and 4-7 mm inhibition zone forming. In vivo test was applied in green house in 30 days old of tomatoes usingendophytic bacteria by theroot soak technique. The result shows Ps1 and Ps8 within 15-16 days incubation period have suppressed 8.07%-9.19% pathogen attack.

  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. Detection of Bacterial Wilt Pathogen and Isolation of Its Bacteriophage from Banana in Lumajang Area, Indonesia

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    Hardian Susilo Addy

    2016-01-01

    Full Text Available Bacterial wilt disease on banana is an important disease in Lumajang District and causes severe yield loss. Utilizing bacteriophage as natural enemy of pathogenic bacteria has been widely known as one of the control strategies. This research was aimed at determining the causing agent of bacterial wilt on banana isolated from Lumajang area, to obtain wide-host range bacteriophages against bacterial wilt pathogen and to know the basic characteristic of bacteriophages, particularly its nucleic acid type. Causative agent of bacterial wilt was isolated from symptomatic banana trees from seven districts in Lumajang area on determinative CPG plates followed by rapid detection by PCR technique using specific pair-primer. Bacteriophages were also isolated from soil of infected banana crop in Sukodono District. Morphological observation showed that all bacterial isolates have similar characteristic as common bacterial wilt pathogen, Ralstonia solanacearum. In addition, detection of FliC region in all isolates confirmed that all isolates were R. solanacearum according to the presence of 400 bp of FliC DNA fragment. Moreover, two bacteriophages were obtained from this experiment (ϕRSSKD1 and ϕRSSKD2, which were able to infect all nine R. solanacearum isolates. Nucleic acid analysis showed that the nucleic acid of bacteriophages was DNA (deoxyribonucleic acid.

  5. Bioorganic fertilizer enhances soil suppressive capacity against bacterial wilt of tomato.

    Science.gov (United States)

    Liu, Lijuan; Sun, Chengliang; Liu, Shuangri; Chai, Rushan; Huang, Weiqing; Liu, Xingxing; Tang, Caixian; Zhang, Yongsong

    2015-01-01

    Tomato bacterial wilt caused by Ralstonia solanacearum is one of the most destructive soil-borne diseases. Many strategies have been taken to improve soil suppressiveness against this destructive disease, but limited success has been achieved. In this study, a novel bioorganic fertilizer revealed a higher suppressive ability against bacterial wilt compared with several soil management methods in the field over four growing seasons from March 2011 to July 2013. The application of the bioorganic fertilizer significantly (Pfertilizer increased soil pH value, electric conductivity, organic carbon, NH4+-N, NO3--N and available K content, microbial activities and microbial biomass carbon content, which were positively related with soil suppressiveness. Bacterial and actinomycete populations assessed using classical plate counts were highest, whereas R. solanacearum and fungal populations were lowest in soil applied with the bioorganic fertilizer. Microbial community diversity and richness were assessed using denaturing gel gradient electrophoresis profile analysis. The soil treated with the bioorganic fertilizer exhibited higher bacterial community diversity but lower fungal community diversity. Redundancy analysis showed that bacterial community diversity and richness negatively related with bacterial wilt suppressiveness, while fungal community richness positively correlated with R. solanacearum population. We concluded that the alteration of soil physicochemical and biological properties in soil treated with the bioorganic fertilizer induced the soil suppressiveness against tomato bacterial wilt.

  6. Recent trends in control methods for bacterial wilt diseases caused by Ralstonia solanacearum.

    Science.gov (United States)

    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 Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases.

  7. Phytobiocidal management of bacterial wilt of tomato caused by Ralstonia solanacearum (Smith) Yabuuchi

    OpenAIRE

    Naseerud Din; Musharaf Ahmad; Muhammad Siddique; Asad Ali; Ishrat Naz; Najeeb Ullah; Fayaz Ahmad

    2016-01-01

    Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue), Calotropis procera (sodom apple), Melia azedarach (white cedar), Allium sativum (garlic), Adhatoda vasica (malabar nut), Tagetes patula (marigold) and Nerium oleander (oleander) were asse...

  8. Differential Control Efficacies of Vitamin Treatments against Bacterial Wilt and Grey Mould Diseases in Tomato Plants

    Science.gov (United States)

    Hong, Jeum Kyu; Kim, Hyeon Ji; Jung, Heesoo; Yang, Hye Ji; Kim, Do Hoon; Sung, Chang Hyun; Park, Chang-Jin; Chang, Seog Won

    2016-01-01

    Bacterial wilt and grey mould in tomato plants are economically destructive bacterial and fungal diseases caused by Ralstonia solanacearum and Botrytis cinerea, respectively. Various approaches including chemical and biological controls have been attempted to arrest the tomato diseases so far. In this study, in vitro growths of bacterial R. solanacearum and fungal B. cinerea were evaluated using four different vitamins including thiamine (vitamin B1), niacin (vitamin B3), pyridoxine (vitamin B6), and menadione (vitamin K3). In planta efficacies of the four vitamin treatments on tomato protection against both diseases were also demonstrated. All four vitamins showed different in vitro antibacterial activities against R. solanacearum in dose-dependent manners. However, treatment with 2 mM thiamine was only effective in reducing bacterial wilt of detached tomato leaves without phytotoxicity under lower disease pressure (106 colony-forming unit [cfu]/ml). Treatment with the vitamins also differentially reduced in vitro conidial germination and mycelial growth of B. cinerea. The four vitamins slightly reduced the conidial germination, and thiamine, pyridoxine and menadione inhibited the mycelial growth of B. cinerea. Menadione began to drastically suppress the conidial germination and mycelial growth by 5 and 0.5 mM, respectively. Grey mould symptoms on the inoculated tomato leaves were significantly reduced by pyridoxine and menadione pretreatments one day prior to the fungal challenge inoculation. These findings suggest that disease-specific vitamin treatment will be integrated for eco-friendly management of tomato bacterial wilt and grey mould. PMID:27721697

  9. Effects of Biochar Amendment on Tomato Bacterial Wilt Resistance and Soil Microbial Amount and Activity

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    Yang Lu

    2016-01-01

    Full Text Available Bacterial wilt is a serious soilborne disease of Solanaceae crops which is caused by Ralstonia solanacearum. The important role of biochar in enhancing disease resistance in plants has been verified; however, the underlying mechanism remains not fully understood. In this study, two different biochars, made from peanut shell (BC1 and wheat straw (BC2, were added to Ralstonia solanacearum-infected soil to explore the interrelation among biochar, tomato bacterial wilt, and soil microbial properties. The results showed that both BC1 and BC2 treatments significantly reduced the disease index of bacterial wilt by 28.6% and 65.7%, respectively. The populations of R. solanacearum in soil were also significantly decreased by biochar application. Ralstonia solanacearum infection significantly reduced the densities of soil bacteria and actinomycetes and increased the ratio of soil fungi/bacteria in the soil. By contrast, BC1 and BC2 addition to pathogen-infected soil significantly increased the densities of soil bacteria and actinomycetes but decreased the density of fungi and the ratios of soil fungi/bacteria and fungi/actinomycetes. Biochar treatments also increased soil neutral phosphatase and urease activity. Furthermore, higher metabolic capabilities of microorganisms by biochar application were found at 96 and 144 h in Biolog EcoPlates. These results suggest that both peanut and wheat biochar amendments were effective in inhibiting tomato bacterial wilt caused by R. solanacearum. The results suggest a relationship between the disease resistance of the plants and the changes in soil microbial population densities and activity.

  10. Changes in the bacterial community and composition of fermentation products during ensiling of wilted Italian ryegrass and wilted guinea grass silages.

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    Li, Yanbing; Nishino, Naoki

    2013-08-01

    To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3-Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre-ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre-ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre-ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.

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

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    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.

  12. Bacterial Wilt and Boron Deficiency Stress: A New Disorder in Eucalypt Plantations in South China

    Institute of Scientific and Technical Information of China (English)

    DELL Bernard; XU Daping

    2006-01-01

    This paper reports on a new disorder that first appeared in eucalypt plantations in south China in 2003. The plantations were destructively sampled near Leizhou, Yanxi, Kaiping and Gaoyao in September to December 2003. Whilst some 5% of 0.5 to 1.5 year-old Eucalyptus urophylla trees declined rapidly and exhibited symptoms of wilting, the majority of the affected trees declined slowly and exhibited two foliar symptoms. Young leaves initially developed an interveinal chlorosis extending from the leaf margin inwards to the midrib. Most leaves then developed pockets of necrotic tissue that became bleached but typically had brown margins. The former symptoms have been recognised as being caused by limited boron supply in soil, but the latter symptoms have not been previously observed in eucalypts in China. Inorganic analysis showed that the leaves with the latter symptoms had deficient B concentrations whereas the leaves from healthy trees had adequate B concentrations. Bacterial wilt, Ralstonia solanacearum, was present at all sites where foliar symptoms and tree death were present. The root system of all trees with foliar chlorosis and necrosis had signs of infection in some roots and attrition of lateral roots. The trunk and branches of the recently died trees and the trees with advanced leaf drop had discoloured xylem, which on cutting, oozed bacterial slime. Possible relationships between root damage caused by abiotic (e.g. typhoons, root damage from hand weeding) and biotic factors and reduced B uptake are discussed. Recommendations are made for reducing bacterial wilt disease and improving B management in fast-growing short-rotation eucalypt plantations.

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

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    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. Phytobiocidal management of bacterial wilt of tomato caused by Ralstonia solanacearum (Smith) Yabuuchi

    Energy Technology Data Exchange (ETDEWEB)

    Din, N.; Ahmad, M.; Siddique, M.; Ali, A.; Naz, I.; Ullah, N.; Ahmad, F.

    2016-11-01

    Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue), Calotropis procera (sodom apple), Melia azedarach (white cedar), Allium sativum (garlic), Adhatoda vasica (malabar nut), Tagetes patula (marigold) and Nerium oleander (oleander) were assessed for their anti-microbial activity, both in-vitro (10% w/v) and in-vivo (10, 20, 30, and 40 g/kg of potted soil) against R. solanacearum. Aqueous extracts (prepared as 10% w/v, soaking for 48-72 h and filtering) of C. procera, A. vasica, and T. patula inhibited the in-vitro growth of the bacterial pathogen over 60% of that produced by the standard antibiotic streptomycin. A. sativum, N. oleander and P. harmala aqueous extracts were less effective while M. azedarach showed no effect against R. solanacearum. The higher dose (40 g/kg of soil) of C. procera, A. vasica and T. patula decreased disease severity quite effectively and increased yield and plant growth characters as much as the standard antibiotic did. No phytotoxicity of medicinal plants powder was observed on tomato plants. Alkaloids, flavonoids, tannins, saponins and terpenoids were detected in the aqueous extracts of T. patula and A. vasica whereas C. procera was found to have only alkaloids, flavonoids, tannins and saponins. Our data suggest that dried powders of T. patula, C. procera and A. vasica (40 g/kg of soil) could be used as an effective component in the integrated disease management programs against bacterial wilt of tomato. (Author)

  16. Phytobiocidal management of bacterial wilt of tomato caused by Ralstonia solanacearum (Smith Yabuuchi

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    Naseerud Din

    2016-08-01

    Full Text Available Phytobiocides are a good alternative to chemicals in managing bacterial diseases including bacterial wilt of tomato caused by Ralstonia solanacearum. In the present research study, finely ground dried powders of seven widely available medicinal plants/weeds species viz., Peganum harmala (esfand or wild rue, Calotropis procera (sodom apple, Melia azedarach (white cedar, Allium sativum (garlic, Adhatoda vasica (malabar nut, Tagetes patula (marigold and Nerium oleander (oleander were assessed for their anti-microbial activity, both in-vitro (10% w/v and in-vivo (10, 20, 30, and 40 g/kg of potted soil against R. solanacearum. Aqueous extracts (prepared as 10% w/v, soaking for 48-72 h and filtering of C. procera, A. vasica, and T. patula inhibited the in-vitro growth of the bacterial pathogen over 60% of that produced by the standard antibiotic streptomycin. A. sativum, N. oleander and P. harmala aqueous extracts were less effective while M. azedarach showed no effect against R. solanacearum. The higher dose (40 g/kg of soil of C. procera, A. vasica and T. patula decreased disease severity quite effectively and increased yield and plant growth characters as much as the standard antibiotic did. No phytotoxicity of medicinal plants powder was observed on tomato plants. Alkaloids, flavonoids, tannins, saponins and terpenoids were detected in the aqueous extracts of T. patula and A. vasica whereas C. procera was found to have only alkaloids, flavonoids, tannins and saponins. Our data suggest that dried powders of T. patula, C. procera and A. vasica (40 g/kg of soil could be used as an effective component in the integrated disease management programs against bacterial wilt of tomato.

  17. [Diversity of soil bacterial community in banana orchards infected with wilt disease].

    Science.gov (United States)

    Chen, Bo; Huang, Xiao; Liu, Xiao-yu; Zhou, Deng-bo; Tan, Xin; Gao, Zhu-fen; Zhang, Xi-yan; Qi, Chun-lin

    2013-08-01

    Six soil samples including 3 wilt disease-infected samples and 3 disease-free samples were collected from the banana orchards in 3 areas in Lingao County, Hainan Province of South China. The soil physical and chemical properties were determined by conventional methods, and the diversity of soil bacterial community was analyzed by terminal restriction fragment length polymorphism (T-RFLP). Then, the relationships between the soil bacterial community composition and the soil physical and chemical properties were investigated. In the same areas, most of the soil physical and chemical properties were poorer in disease-infected than in disease-free banana orchards, with the most obvious difference in soil available P content and pH. The T-RFLP analysis showed the diversity of soil bacterial community was richer in disease-infected than in disease-free banana orchards. The lengths of the dominant T-RFs in the 3 areas were 144, 147 and 233 bp, respectively. Through the comparison with phylogenetic assignment tool, it was deduced that the dominant species in the 3 areas were Bacillus subtilis, Staphylococcus and Eubacterium ruminantium. The distribution of most T-RFs was related to the soil alkaline hydrolyzable N, available K, available P and water content, and the relative abundance of most T-RFs was richer in disease-infected than in disease-free banana orchards.

  18. Microbial taxa and functional genes shift in degraded soil with bacterial wilt

    Science.gov (United States)

    Zhang, Hongchun; Wang, Rui; Chen, Shu; Qi, Gaofu; He, Zhili; Zhao, Xiuyun

    2017-01-01

    Soil degradation is a serious global problem, but little is known about how soil microbial communities respond to soil degradation as well as their feedback to ecosystem functioning. In this study, we found the microbial community composition, structure and functional potential significantly altered in the degraded soils with bacterial wilt (termed as degraded soils). Compared with healthy soils, OTU richness of beneficial microorganisms were significantly decreased, but OTU richness of pathogenic microorganisms were significantly increased in the degraded soils. Functional gene array (GeoChip 5.0) analysis showed the functional metabolic potential of genes involved in stress, virulence, sulfur cycle, metal resistance, degradation of plant cell wall was significantly increased in the degraded soils. Increased functional metabolic potential of these genes may be related to the acidification and severe plant disease of degraded soils. Biological activity of degraded soils was obviously decreased with weakened soil enzyme activities when compared to the healthy soils. Soil pH and enzyme activities were negatively correlated with the abundance of genes involved in sulfur cycle, virulence, and stress responses. This study provides new insights into our understanding of soil microbial community responses to soil degradation. PMID:28051173

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

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

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    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.

  1. 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.

  2. 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

    2011-01-01

    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...... assisted resistance breeding....

  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. Variables Associated with Severity of Bacterial Canker and Wilt Caused by Clavibacter michiganensis subsp. michiganensis in Tomato Greenhouses.

    Science.gov (United States)

    Blank, L; Cohen, Y; Borenstein, M; Shulhani, R; Lofthouse, M; Sofer, M; Shtienberg, D

    2016-03-01

    Clavibacter michiganensis subsp. michiganensis, the causal agent of bacterial canker and wilt of tomato, is considered to be one of the most important bacterial pathogens worldwide. In the year 2000 there was an increase in the number of infected greenhouses and in the severity of the disease in Israel. As part of the effort to cope with the disease, a comprehensive survey was conducted. Scouts recorded disease severity monthly in 681 production units. At the end of the season the scouts met with the growers and together recorded relevant details about the crop and cultural practices employed. The results suggested an absence of anisotropy pattern in the study region. Global Moran's I analysis showed that disease severity had significant spatial autocorrelation. The strongest spatial autocorrelation occurred within a 1,500 m neighborhood, which is comparable to the distance between production units maintained by one grower (Farm). Next, we tested three groups of variables including or excluding the Farm as a variable. When the Farm was included the explained variation increased in all the studied models. Overall, results of this study demonstrate that the most influential factor on bacterial canker severity was the Farm. This variable probably encompasses variation in experience, differences in agricultural practices between growers, and the quality of implementation of management practices.

  5. Bacillus volatiles adversely affect the physiology and ultra-structure of Ralstonia solanacearum and induce systemic resistance in tobacco against bacterial wilt

    Science.gov (United States)

    Tahir, Hafiz Abdul Samad; Gu, Qin; Wu, Huijun; Niu, Yuedi; Huo, Rong; Gao, Xuewen

    2017-01-01

    Volatile organic compounds (VOCs) produced by various bacteria have significant potential to enhance plant growth and to control phytopathogens. Six of the most effective antagonistic Bacillus spp. were used in this study against Ralstonia solanacearum (Rsc) TBBS1, the causal agent of bacterial wilt disease in tobacco. Bacillus amyloliquefaciens FZB42 and Bacillus artrophaeus LSSC22 had the strongest inhibitory effect against Rsc. Thirteen VOCs produced by FZB42 and 10 by LSSC22 were identified using gas chromatography-mass spectrometry analysis. Benzaldehyde, 1,2-benzisothiazol-3(2 H)-one and 1,3-butadiene significantly inhibited the colony size, cell viability, and motility of pathogens and negatively influenced chemotaxis. Transmission and scanning electron microscopy revealed severe morphological and ultra-structural changes in cells of Rsc. Furthermore, VOCs altered the transcriptional expression level of PhcA (a global virulence regulator), type III secretion system (T3SS), type IV secretion system (T4SS), extracellular polysaccharides and chemotaxis-related genes, which are major contributors to pathogenicity, resulting in decreased wilt disease. The VOCs significantly up-regulated the expression of genes related to wilt resistance and pathogen defense. Over-expression of EDS1 and NPR1 suggest the involvement of SA pathway in induction of systemic resistance. Our findings provide new insights regarding the potential of antibacterial VOCs as a biocontrol tool against bacterial wilt diseases. PMID:28091587

  6. 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

    2015-12-10

    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.

  7. 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.

  8. Suppression of bacterial wilt of tomato by bioorganic fertilizer made from the antibacterial compound producing strain Bacillus amyloliquefaciens HR62.

    Science.gov (United States)

    Huang, Jianfeng; Wei, Zhong; Tan, Shiyong; Mei, Xinlan; Shen, Qirong; Xu, Yangchun

    2014-11-05

    Ralstonia solanacearum (Smith) is an important soil-borne pathogen worldwide. We investigated the effects of a new bioorganic fertilizer, BIO62, which was made from organic fertilizer and antagonist Bacillus amyloliquefaciens HR62, on the control of bacterial wilt of tomato in greenhouse condition. The results showed that the application of BIO62 significantly decreased disease incidence by 65% and strongly reduced R. solanacearum populations both in the rhizosphere soil (8.04 log cfu g(-1) dry soil) and crown sections (5.63 log cfu g(-1) fresh plant section) at 28 days after pathogen challenge. Antibacterial compounds produced by HR62 were purified by silica gel, Sephadex LH-20, and HPLC and then identified using HPLC/electrospray ionization mass spectrometry analysis. Macrolactin A and 7-O-malonyl macrolactin A (molecular weights of 402 and 488 Da, respectively), along with surfactin B (molecular weights of 994, 1008, 1022, and 1036 Da), were observed to inhibit the growth of R. solanacearum.

  9. Characterization and evaluation of Bacillus amyloliquefaciens strain WF02 regarding its biocontrol activities and genetic responses against bacterial wilt in two different resistant tomato cultivars.

    Science.gov (United States)

    Huang, Chu-Ning; Lin, Chan-Pin; Hsieh, Feng-Chia; Lee, Sook-Kuan; Cheng, Kuan-Chen; Liu, Chi-Te

    2016-11-01

    Bacillus amyloliquefaciens strain WF02, isolated from soil collected at Wufeng Mountain, Taiwan, has siderophore-producing ability and in vitro antagonistic activity against bacterial wilt pathogen. To determine the impact of plant genotype on biocontrol effectiveness, we treated soil with this strain before infecting susceptible (L390) and moderately resistant (Micro-Tom) tomato cultivars with Ralstonia solanacearum strain Pss4. We also compared the efficacy of this strain with that of commercial Bacillus subtilis strain Y1336. Strain WF02 provided longer lasting protection against R. solanacearum than did strain Y1336 and controlled the development of wilt in both cultivars. To elucidate the genetic responses in these plants under WF02 treatment, we analyzed the temporal expression of defense-related genes in leaves. The salicylic acid pathway-related genes phenylalanine ammonia-lyase and pathogenesis-related protein 1a were up-regulated in both cultivars, whereas expression of the jasmonic acid pathway-related gene lipoxygenase was only elevated in the susceptible tomato cultivar (L390). These results suggest that WF02 can provide protection against bacterial wilt in tomato cultivars with different levels of disease resistance via direct and indirect modes of action.

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

    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。

  11. 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

  12. Deep 16S rRNA pyrosequencing reveals a bacterial community associated with Banana Fusarium Wilt disease suppression induced by bio-organic fertilizer application.

    Directory of Open Access Journals (Sweden)

    Zongzhuan Shen

    Full Text Available Our previous work demonstrated that application of a bio-organic fertilizer (BIO to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas.

  13. Deep 16S rRNA pyrosequencing reveals a bacterial community associated with Banana Fusarium Wilt disease suppression induced by bio-organic fertilizer application.

    Science.gov (United States)

    Shen, Zongzhuan; Wang, Dongsheng; Ruan, Yunze; Xue, Chao; Zhang, Jian; Li, Rong; Shen, Qirong

    2014-01-01

    Our previous work demonstrated that application of a bio-organic fertilizer (BIO) to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs) were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas.

  14. Occurrence and Control Measures of Peanut Stem Rot and Bacterial Wilt in Guangxi%广西花生茎腐病及青枯病的发生与防治

    Institute of Scientific and Technical Information of China (English)

    钟瑞春; 熊发前; 韩柱强

    2012-01-01

    总结广西花生茎腐病、青枯病的侵染途径、症状表现,有针对性地提出了防治对策,以为花生茎腐病、青枯病的防治提供参考。%The symptoms and infection pathway of Guangxi peanut stem rot and bacterial wilt disease were summarized. Control strategies were proposed to provide theoretical reference for controlling the peanut stem rot and bacterial wilt disease.

  15. Comparison of the transcriptomes of ginger (Zingiber officinale Rosc.) and mango ginger (Curcuma amada Roxb.) in response to the bacterial wilt infection.

    Science.gov (United States)

    Prasath, Duraisamy; Karthika, Raveendran; Habeeba, Naduva Thadath; Suraby, Erinjery Jose; Rosana, Ottakandathil Babu; Shaji, Avaroth; Eapen, Santhosh Joseph; Deshpande, Uday; Anandaraj, Muthuswamy

    2014-01-01

    Bacterial wilt in ginger (Zingiber officinale Rosc.) caused by Ralstonia solanacearum is one of the most important production constraints in tropical, sub-tropical and warm temperature regions of the world. Lack of resistant genotype adds constraints to the crop management. However, mango ginger (Curcuma amada Roxb.), which is resistant to R. solanacearum, is a potential donor, if the exact mechanism of resistance is understood. To identify genes involved in resistance to R. solanacearum, we have sequenced the transcriptome from wilt-sensitive ginger and wilt-resistant mango ginger using Illumina sequencing technology. A total of 26387032 and 22268804 paired-end reads were obtained after quality filtering for C. amada and Z. officinale, respectively. A total of 36359 and 32312 assembled transcript sequences were obtained from both the species. The functions of the unigenes cover a diverse set of molecular functions and biological processes, among which we identified a large number of genes associated with resistance to stresses and response to biotic stimuli. Large scale expression profiling showed that many of the disease resistance related genes were expressed more in C. amada. Comparative analysis also identified genes belonging to different pathways of plant defense against biotic stresses that are differentially expressed in either ginger or mango ginger. The identification of many defense related genes differentially expressed provides many insights to the resistance mechanism to R. solanacearum and for studying potential pathways involved in responses to pathogen. Also, several candidate genes that may underline the difference in resistance to R. solanacearum between ginger and mango ginger were identified. Finally, we have developed a web resource, ginger transcriptome database, which provides public access to the data. Our study is among the first to demonstrate the use of Illumina short read sequencing for de novo transcriptome assembly and comparison in

  16. 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

  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 Different Preservation Methods on Pathogenicity of Bacterial Wilt Strains in Tobacco%烟草青枯病菌种保存方法及其对致病力的影响

    Institute of Scientific and Technical Information of China (English)

    陆铮铮; 彭丽娟; 丁海霞; 蒋选利; 彭杰

    2011-01-01

    Three strain preservation methods of tissue culture tobacco plantlets, sterilized distilled water under normal temperature and slant culture in a refrigerator were compared to study the effect of different preservation methods on pathogenicity of tobacco bacterial wilt bacteria and to select higher pathogenicity stains for control and resistance identification of tobacco bacterial wilt. The results showed that the tissue culture tobacco plantlets preservation and sterilized distilled water preservation under normal temperature both could keep the pathogenicity activity of bacterial wilt bacteria, and the tissue culture tobacco plantlets preservation was better than the sterilized distilled water preservation under normal temperature. When preservation of tobacco bacterial wilt strains is used to extract crude toxin, the sterilized distilled water preservation under normal temperature is better than the tissue culture tobacco plantlets preservation.%为在烟草青枯病的防治和烟草抗病性鉴定研究中获得致病力较强的菌株,分别采用烟草组培苗活体保存、灭菌蒸馏水常温保存以及料面冰箱保存3种不同方法保存烟草青枯病菌,并比较了3种保存方法对烟草青枯病菌致病力的影响.结果表明:烟草组培苗活体保存法和灭菌蒸馏水常温保存法均具有较好的保持青枯病菌致病力活性的能力,前者比后者稍强,如需提取粗毒素,则建议使用后者,斜面冰箱保存法的致病力下降最快.

  19. 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.

  20. Loop-mediated isothermal amplification of specific endoglucanase gene sequence for detection of the bacterial wilt pathogen Ralstonia solanacearum.

    Directory of Open Access Journals (Sweden)

    Rok Lenarčič

    Full Text Available The increased globalization of crops production and processing industries also promotes the side-effects of more rapid and efficient spread of plant pathogens. To prevent the associated economic losses, and particularly those related to bacterial diseases where their management relies on removal of the infected material from production, simple, easy-to-perform, rapid and cost-effective tests are needed. Loop-mediated isothermal amplification (LAMP assays that target 16S rRNA, fliC and egl genes were compared and evaluated as on-site applications. The assay with the best performance was that targeted to the egl gene, which shows high analytical specificity for diverse strains of the betaproteobacterium Ralstonia solanacearum, including its non-European and non-race 3 biovar 2 strains. The additional melting curve analysis provides confirmation of the test results. According to our extensive assessment, the egl LAMP assay requires minimum sample preparation (a few minutes of boiling for the identification of pure cultures and ooze from symptomatic material, and it can also be used in a high-throughput format in the laboratory. This provides sensitive and reliable detection of R. solanacearum strains of different phylotypes.

  1. Incidência de murcha-bacteriana em tomate para processamento industrial sob irrigação por gotejamento e aspersão Incidence of bacterial wilt on processing tomato under drip and sprinkle irrigation

    Directory of Open Access Journals (Sweden)

    Waldir A. Marouelli

    2005-06-01

    Full Text Available O estudo foi realizado na Embrapa Hortaliças, Brasília (DF, com o objetivo de avaliar a incidência de murcha-bacteriana em tomateiro para processamento industrial irrigado por gotejamento e por aspersão, cultivado em solo naturalmente infestado com a raça 1, biovar I de Ralstonia solanacearum, nas condições edafoclimáticas do Cerrado brasileiro. Para gotejamento foram também avaliados os regimes hídricos com turnos de rega de 0,5; 1; 2; 4 e 8 dias. A irrigação por gotejamento favoreceu significativamente a ocorrência da doença, apresentando em média, aos 65 dias após o transplante de mudas, 42,5% de plantas com sintoma contra 5% de casos ocorridos na irrigação por aspersão. A incidência da doença no gotejamento não foi afetada (p>0,05 pelo regime hídrico adotado.A field experiment was carried out at Embrapa Hortaliças, Brasilia, Brazil, with the objective of assessing the incidence of bacterial wilt on processing tomatoes irrigated by drip and sprinkle systems, under soil and climate conditions of the Brazilian "Cerrado". The trial was performed in a field naturally infested with race 1, biovar I of Ralstonia solanacearum. Different irrigation frequencies (0.5; 1; 2; 4; and 8 days were further evaluated for drip irrigation. Disease incidence was significantly higher when the crop was drip irrigated, with an average of 42.5% of wilted plants in comparison with 5.0% incidence for sprinkle irrigation, 65 days after transplanting. Frequencies of drip irrigation did not affect (p>0.05 bacterial wilt incidence.

  2. 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

  3. 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

  4. 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

  5. Draft Genome Sequence of Highly Virulent Race 4/Biovar 3 of Ralstonia solanacearum CaRs_Mep Causing Bacterial Wilt in Zingiberaceae Plants in India

    Science.gov (United States)

    Munjal, Vibhuti; Sheoran, Neelam; Prameela, Thekkan Puthiyaveedu; Suseelabhai, Rajamma; Aggarwal, Rashmi; Jain, Rakesh Kumar; Eapen, Santhosh J.

    2017-01-01

    ABSTRACT The genome of Ralstonia solanacearum CaRs_Mep, a race 4/biovar 3/phylotype I bacterium causing wilt in small cardamom and other Zingiberaceae plants, was sequenced. Analysis of the 5.7-Mb genome sequence will aid in better understanding of the genetic determinants of host range, host jump, survival, pathogenicity, and virulence of race 4 of R. solanacearum. PMID:28057749

  6. 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

  7. 广藿香辐射诱变筛选抗病突变体的研究%Selection of Bacterial-wilt-resistance Mutants of Pogostemon cablin (Blanco) Benth.by Radiation Mutation

    Institute of Scientific and Technical Information of China (English)

    贺红; 许仕仰; 吴立蓉; 张燕玲

    2012-01-01

    Objective To select the bacterial-wilt-resistance mutants of Pogostemon cablin (Blanco) Benth. By 60Co γ ray radiation mutation, so as to lay a foundation for disease-resistance breeding. Methods The effects of 60Co γ ray radiation on plant regeneration from the explants of Pogostemon cablin were studied. The explants from regenerated plants after radiation mutation were cultured in the media supplemented with crude toxin extracted from Ralstonia solanacearum, and then the mutants resistant to bacterial wilt in Pogostemon cablin were selected. Results The crude toxins extracted from 1.34×108 cfu/mL and 2.48×108 cfu/mL R. Solanacearum were suitable for screening resistant shoots and resistant plant respectively. Survival rate and regenerated ability of the explants irradiated by 60Co γ ray were decreased with the increase of radiation dose. The radiation dose of 40 Gy and 60 Gy was suitable for mutation breeding. After 60Co γ ray radiation mutation combined with in vitro selection, 24 resistant plants were obtained. Conclusion A proper method for selection of the bacterial-wilt-resistance mutants of Pogostemon cablin has been established, which will supply valuable germplasm for disease-resistance breeding of Pogostemon cablin.%[目的]将辐射诱变与离体选择相结合,筛选广藿香抗青枯病突变体,为广藿香抗病育种奠定基础.[方法]观察60Coγ射线辐射对广藿香离体再生的影响;以辐射诱变的广藿香为材料,以青枯菌粗毒素为选择压力,筛选抗青枯病植株.[结果]在进行抗性芽及抗性植株筛选中,分别以1.34×108 cfu(菌落形成单位)/mL及2.48×108 cfu/mL青枯菌制备的粗毒素作为选择压力,可能筛选到抗性的材料.60Co γ射线辐射对广藿香离体再生有明显的影响,随着辐射剂量的增加,外植体存活率及再生芽的能力显著下降.最终选取剂量为40 Gy和60 Gy进行辐射诱变,结合离体培养筛选抗病突变体,获得了24株抗性植株.[

  8. Fusarium Wilt of Orchids

    Science.gov (United States)

    Fusarium wilt of orchids is highly destructive and economically limiting to the production of quality orchids that has steadily increased in many production facilities. Important crops such as phalaenopsis, cattleyas, and oncidiums appear to be especially susceptible to certain Fusarium species. Fu...

  9. 枯草芽孢杆菌SB1的抑菌活性及其对番茄青枯病的防治作用%Antagonistic Activity of Bacillus subtilis SB1 and its Biocontrol Effect on Tomato Bacterial Wilt

    Institute of Scientific and Technical Information of China (English)

    连玲丽; 谢荔岩; 吴祖建; 谢联辉; 段永平

    2011-01-01

    Bacillus subtilis strain SB1 isolated from tomato roots was evaluated for its ability to control tomato bacterial wilt under greenhouse conditions. Application of strain SB1 culture suspension suppressed tomato wilt disease both in sterilized and non-sterilized soil, providing 76. 03% and 77.78% protection, respectively.Wilt symptom was significantly reduced when strain SB1 was applied before pathogen inoculation, while less suppression was conferred by strain SB1 application after pathogen inoculation. The result implied that strain SB1 exhibited both preventive and therapeutic effects on tomato wilt disease. Inhibition abilities of different fractions of strain SB1 suspension were examined as well. Results indicated that treatments with whole cell suspension and culture filtrate gave 71.77% and 65.88% protection, respectively, which were significantly higher than those of the washed cell. This experiment indicated that suppression by strain SB1 was mainly the consequence of activity of the culture filtrate. The possible action mechanisms of the culture filtrate on Ralstonia solanacearum were investigated. The pathogen's cell shape was greatly altered by the culture filtrate, and the protein expression profiles of R. solanacearum were also affected.

  10. 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.

  11. 高抗青枯病花生新品种贺油14的选育%Breeding of Heyou14, a New Peanut Variety with Bacterial Wilt Resistance

    Institute of Scientific and Technical Information of China (English)

    吴昌湛; 陈庆政; 韦汉文; 吴春玲; 李战; 冯晓佳; 卢梦娴

    2015-01-01

    贺油14是广西贺州市农业科学研究所以梧油1号作母本、汕油523作父本进行有性杂交选育而成的珍珠豆型花生新品种。经广西花生品种区域试验,该品种具有丰产性好、高抗青枯病、锈病和叶斑病、适应性广等特点。2012年6月通过广西农作物品种审定委员会审定,适宜在南方花生产区种植。%Derived from the cross of Wuyou 1 × Shanyou 523, Heyou14 was a Spanish-type pea-nut cultivar bred by Hezhou Agricultural Science Research Institute.In Guangxi Regional Pre-release Variety Evaluation Tests, Heyou14 showed high pod yield, high resistance against bacterial wilt, rust and leaf spots diseases, and wide adaptability.It was approved for release in Guangxi by Guangxi Pro-vincial Crops Approval Committee in 2012.Heyou14 are suitable for being planted in southern peanut production region in China.

  12. 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.

  13. 健康香蕉(Musa paradisiaca)植株与枯萎病患病植株根区土壤细菌多样性的比较研究%Comparison of Soil Bacterial Genetic Diversity in Root Zone of Banana(Musa paradisiaca) Infected with Fusarium Wilt and Non-Infected Plants

    Institute of Scientific and Technical Information of China (English)

    邓晓; 李勤奋; 武春媛; 李怡; 刘景坤

    2015-01-01

    Currently banana fusarium wilt (Fusarium oysporumf. cubense) is one of the important soil-borne diseases of seriously threat to banana production. However, there is no effective method for prevention in the world. The objective of this study was providing research information for the prevention of banana fusarium wilt from the perspective of microbial ecology. Two gene libraries of 16S rRNA were constructed by directly extracted from soil total DNA. And the soil samples were collected from root zone of banana which infected with fusarium wilt and non-infected plants in three typical plots infected by banana fusarium wilt (Jianfeng, Shiyuetian, Chongpo) in Hainan Province. The soil bacterial genetic diversity was analyzed by DNA sequencing and phylogenetic characters. The results were shown as follows: (1) the number of operational taxonomic units (OTUs) in soils from root zone of banana which infected with fusarium wilt was 18 lower than that of non-infected plants. The Shannon index (H') and calculated species richness (Schao1) in soils from root zone of banana which infected with fusarium wilt was respectively 0.66 and 26 lower than that of non-infected plants. (2) 63 OTUs were belonged to 9 bacterial taxa and 4 non-determined genotypes in soils from non-infected plants, and 45 OTUs were belonged to 8 bacterial taxa and 2 non-determined genotypes in soils from fusarium wilt infected plants. And the 6 bacterial phyla of Firmicutes, Proteobacteria, Actinobacteria, Acidobacteria, Gemmatimonadetes and Planctomycetes among them were common bacterial taxa in soils from root zone of banana both infected with fusarium wilt and non-infected plants. However, Cyanobacteria and Bacteria intertae sedis were only existed in the soils from root zone of banana plants which non-infected with fusarium wilt. In contrast, Nitrospia was only observed in the soils from root zone of infected plants. (3) The proportion of Firmicutes in soils from fusarium wilt infected plants was 11

  14. 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.

  15. 木薯叶片愈伤组织对枯萎病病原菌的抗性筛选%Screening for Cassava Leaf Callus Resistance to Bacterial Wilt

    Institute of Scientific and Technical Information of China (English)

    陆荣生; 韩美丽; 霍秀娟; 马跃峰

    2012-01-01

    以木薯品种“GR911”、“面包木薯”试管苗叶片为材料,研究木薯枯萎病病原菌粗提物对愈伤组织增殖与分化的影响.以期建立枯萎病病原菌粗提物为选择压力的木薯离体抗病筛选体系。结果表明:所用品种幼叶愈伤诱导与增殖的适宜配方为改良的MS培养基+0.5-0.75mg/L2,4一D:愈伤分化适宜配方为的MS培养基+O.75—1.0mg/LZT。“GR911”与“面包木薯”愈伤增殖过程中。愈伤褐化率达到50%所需的细菌液粗提物浓度分别为5.5×、2.5×^6cfu/mE:愈伤组织分化过程中,愈伤褐化率达到50%所需的菌液粗提物浓度分别为7.0×10^6、4.0×10^6cfu/mL。通过建立木薯愈伤组织离体抗病筛选体系。为木薯无性系变异育种奠定基础。%This study was made to clarify the effects of bacterial crude toxin culture on proliferation and differentiation of callus in cassava, to screen system of resistance to bacterial wilt caused by Xanthomonas manihotis (Artheodet Bey.) Stars in vitro. The young leaves from plantlet were used as explants. On basal modified MS medium, the optimum hormone concentration is 0.5-0.75 mg/L 2 ,4-D for induction and proliferation of callus, and 0.75-1.0 mg/ L ZT for differentiation of callus. To achieve 50 % callus browning rate during callus proliferation, the concentration of bacteria crude toxin culture in medium should be 5.5×106 cfu/ml for species GR991 and 2.5× 106 cfu/ml for species MianBao. To get 50 % callus browning rate during callus differentiation, the concentration of bacteria crude toxin culture in medi-um should be 7.0×106 cfu/ml for species GR991 and 4.0× 106 cfu/ml for species MianBao. By this ex- periment, the screening system of resistance to bacterial wilt was established in vitro in cassava, and this system can be used for clone breeding studies.

  16. Breeding of Baozhen No.6, a Bacterial Wilt-resistance Tomato Rootstock Cultivar%抗青枯病番茄砧木品种宝砧6号的选育

    Institute of Scientific and Technical Information of China (English)

    李玉洪; 李业勇; 吴永琼; 滕献有; 莫豪葵; 李刚

    2016-01-01

    宝砧6号是以自交系 Y0609-4-6为母本,自交系 T0802-7-4为父本配置而成的番茄砧木一代杂交种。该品种为无限生长型,生长旺盛,茎秆粗壮,株型紧凑,高抗青枯病;与生产上主栽品种嫁接亲和性好,对果实品质、商品性无不良影响,作砧木嫁接栽培抗青枯病和抗早衰能力效果明显,嫁接种植田后期可延长采收15~20 d,增产幅度超过15%。目前该品种已成为资源车田、永福三皇等番茄产业基地嫁接砧木的主要应用品种,推广应用面积达400 hm2。%Baozhen No.6 is an F1 hybrid of the tomato rootstock using the inbred line Y0609-4-6 as a female parent and the inbred line T0802-7-4 as a male parent. This cultivar has better graft compatibility with main cultivar and many characteristics of infinite growth, strong growth vigor, stocky stem, compact plant type, high resistance to bacterial wilt. In addition, the fruit quality and marketability could not be affected adversely. The grafted tomato has high resistance to bacterial disease and premature senility, the harvest period can be extended 15-20 days and its yield can be increased by 15% above in contrast to the control. Currently, this cultivar has been popularized as a major rootstock cultivar on a number of tomato industry bases such as Ziyuanchetian and Yongfusanhuang bases and so on. The cultivated area has reached about 400 hm2.

  17. Preliminary Screening and Evaluation of Bacterial Wilt-resistance Cherry Tomato Cultivars%抗青枯病樱桃番茄品种的初步筛选及评价

    Institute of Scientific and Technical Information of China (English)

    曾莉莎; 刘建平; 胡规媛; 莫秀文; 杜彩娴; 王红; 梁少丽; 吕顺; 李洪波; 郑汉文

    2016-01-01

    对28个樱桃番茄品种的田间抗病性、植株类型、单果质量、果色、可溶性固形物含量等主要经济性状进行调查。试验结果表明,感病品种红艳发病最重,发病率为73.67%,其次是红箭、红日和金艳,发病率分别为23.33%、21.67%和20.33%,其他品种发病率都在20%以下;28个品种的果实颜色、大小、口感等差异明显,除黑宝石映泰及黄金蛋可溶性固形物含量在4.10%以下外,其他品种可溶性固形物含量都达5.20%以上。综合分析,筛选出绿天使、粉仙、红娘9号、绿圆、格丽贝、红椭圆等11个抗青枯病且经济性状优良的樱桃番茄品种,为优质抗青枯病樱桃番茄的选育和推广提供了参考。%This experiment investigated the main economic characteristics of 28 cherry tomato cultivars including disease resistance, plant type, single fruit weight, fruit color, soluble solid content, etc. The results showed that the sensitive cultivar Hongyan had the highest disease incidence, and its disease incidence was 73.67%, followed by Hongjian, Hongri, and Jinyan with the disease incidence of 23.33%, 21.67% and 20.33% respectively, while disease incidence of other tomatoes cultivars were below 20%. 28 cherry tomato cultivars were obvious differences in fruit color, size, taste, etc. Soluble solid content of most tomato cultivars were more than 5.20% besides Heibaoshiyingtai and Huangjingdan, which soluble solid content were blow 4.10%. Other 11 bacterial wilt-resistance cherry tomato cultivars including Lvtianshi, Fenxian, Hongniang No.9, Lvyuan, Gelibei, Hongtuoyuan and so on with excellent economic characteristics were selected out. This study would provide references for cultivar breeding and promotion of cherry tomato.

  18. Identification of Common AFLP Markers Linked with Resistance to Bacterial Wilt in Potato%马铃薯青枯病抗性的共性AFLP标记的初步定位

    Institute of Scientific and Technical Information of China (English)

    郜刚; 金黎平; 屈冬玉; 连勇; 闫桂琴; 段江燕

    2005-01-01

    The bulked Segregant Analysis (BSA) was used to examine and evaluate the feasibility and the efficiency of the identification of markers linked to resistance to bacterial wilt (Ralstonia solanacearum) in potato. A highly resistant primitive cultivated species Solanum phureja was employed to generate a mapping population to perform the bulked segregant analysis for screening of AFLP markers linked with the resistance. Another population which had genetic similarity to the mapping population was used for testing of the markers achieved. A novel strategy named common AFLP marker was used to identify the genomic position of the molecular markers in the linkage map mapped before. Several informative primer combinations were employed in the detection and the common AFLP markers ATG/CTC 307.0, ATG/CTC 246.0, ATG/CTC 191.0 and AAC/CAC 79.0 were considered as markers that associated with the resistance and located on the relevant chromosome maps. The markers were located on chromosome 1 and 12 and may be used for other related studies.%利用集群分类法(bulked segregant analysis, BSA)对与马铃薯青枯病(Ralstonia solanacearum) 抗性连锁的分子标记进行了分析.以马铃薯青枯病高抗性的原始栽培种Solanum phureja获得的二倍体群体为作图群体进行AFLP标记的初步筛选,另选一个与作图群体有较大亲缘关系和相近遗传背景的二倍体群体对所获标记进行验证.在标记鉴定过程中使用了共性AFLP标记(common AFLP marker)的方法.通过与已构建的连锁图谱的比较分析,获得了4个与马铃薯青枯病抗性相关的4个AFLP标记ATG/CTC 307.0, ATG/CTC 246.0, ATG/CTC 191.0和AAC/CAC 79.0,将其分别定位于染色体1和12上,可望应用于其它相关研究.

  19. 不同香蕉枯萎病区土壤细菌群落多样性%Diversity of soil bacterial community in banana orchards infected with wilt disease

    Institute of Scientific and Technical Information of China (English)

    陈波; 黄霄; 刘小玉; 周登博; 谭昕; 高祝芬; 张锡炎; 戚春林

    2013-01-01

    Six soil samples including 3 wilt disease-infected samples and 3 disease-free samples were collected from the banana orchards in 3 areas in Lingao County,Hainan Province of South China.The soil physical and chemical properties were determined by conventional methods,and the diversity of soil bacterial community was analyzed by terminal restriction fragment length polymorphism (T-RFLP).Then,the relationships between the soil bacterial community composition and the soil physical and chemical properties were investigated.In the same areas,most of the soil physical and chemical properties were poorer in disease-infected than in disease-free banana orchards,with the most obvious difference in soil available P content and pH.The T-RFLP analysis showed the diversity of soil bacterial community was richer in disease-infected than in disease-free banana orchards.The lengths of the dominant T-RFs in the 3 areas were 144,147 and 233 bp,respectively.Through the comparison with phylogenetic assignment tool,it was deduced that the dominant species in the 3 areas were Bacillus subtilis,Staphylococcus and Eubacterium ruminantium.The distribution of most T-RFs was related to the soil alkaline hydrolyzable N,available K,available P and water content,and the relative abundance of most T-RFs was richer in disease-infected than in disease-free banana orchards.%分别采集海南省临高县3个地区的香蕉枯萎病发病土壤与健康土壤样品共6份,采用常规方法测定土壤理化性质,以末端限制性片段多态性分析(T-RFLP)技术研究不同地区发病与健康土壤微生物的多样性,并分析土壤微生物群落结构与土壤因子的关系.结果表明:同一地区发病蕉园土壤的大部分理化性质指标低于健康蕉园,以pH、有效P含量的差异最显著;T-RFLP结果表明供试蕉园发病土壤的细菌多样性比健康土壤丰富;3个地区的优势种分别为片段长度为144、147与233 bp的T-RFs,通过系统发

  20. Effects of Different Organic Fertilizer on Growth, Yield, Quality and Bacterial Wilt of Flue-cured Tobacco%不同有机肥对烤烟生长发育、产质量及青枯病的影响

    Institute of Scientific and Technical Information of China (English)

    徐健钦; 徐智; 宋建群; 张云伟; 殷红慧; 李艳红; 达布希拉图; 汤利

    2013-01-01

    通过田间试验,比较研究了不同有机肥(精制有机肥和生物有机肥)与化肥配施对烤烟农艺性状、叶绿素含量、产质量及烤烟青枯病的影响.结果表明:与当地常规施肥(100%化肥)相比,精制有机肥、生物有机肥配施80%化肥,可促进烤烟生长,显著提高烤烟产质量,减轻青枯病的危害.与当地常规施肥(100%化肥)相比,在化肥减量20%的基础上,配施生物有机肥烤烟产量提高了4.5%,产值提高了9.8%,上中等烟比例提高了8.4%,烤烟青枯病病情指数降低了47.3%;配施精制有机肥烤烟产量提高了5.3%,烤烟青枯病病情指数降低了15.8%.与配施精制有机肥处理相比,配施生物有机肥烤烟产值提高了9.5%,上中等烟比例提高了6.2%,烤烟青枯病病情指数降低了37.5%.%The field experiments were carried out to compare and study the effect of combining applica-tion of different organic fertilizer (refined organic fertilizer and bio-organic fertilizer) with chemical fer-tilizer on agronomic characteristics, chlorophyll content, yield and quality and bacterial wilt of flue-cured tobacco. The results showed that; compared with the local conventional fertilization (100% chemical fertilize) , combining application of refined organic fertilizer, and biological organic fertilizer with 80% chemical fertilizer could promote the growth of tobacco; significantly improve the yield and quality of the flue-cured tobacco; reduce the hazards of bacterial wilt. Compared with the local conven-tional fertilization (100% chemical fertilize) , on the basis of the reduction of chemical fertilizer by 20% , the treatment that was combined application of chemical fertilizer with biological organic fertiliz-er produced the following results; yield of flue-cured tobacco increased by 4. 5% ; output value in- creased by 9. 8% ; the proportion of mid-high grade tobacco leaves increased by 8. 4% ; bacterial wilt disease index of flue

  1. Comparison of Control Effect of Common Pestic-ides against Flue-cured Tobacco KRK26 Bacterial Wilt%烤烟品种KRK26青枯病常用药剂防治效果比较

    Institute of Scientific and Technical Information of China (English)

    龚永尉; 李艳琼; 李其久; 杨海燕

    2016-01-01

    针对生产中大面积推广种植的烤烟品种KRK26青枯病发生普遍严重和防效差的问题,选用7种常用杀菌剂进行田间药效试验。结果表明,72%农用链霉素SP 4000倍液+58%甲霜·锰锌WP 1000倍液,于移栽当天、发病初期及其后10 d施药,共施3次药对烤烟品种KRK26青枯病的防治效果最好。%Seven kinds of common bactericides were conducted in field test to the question of the seriousness and the bad control effect of the widespread tobacco wilt in the production of large-area planting flue-cured tobacco. The re-sults showed that the control effect for the flue-cured tobacco KRK26 tobacco wilt was the best applying with 72% a-gricultural streptomycin SP 4 000 times+ 58% metalaxyl, mancozeb WP 1 000 at the day of transplanting, in the early stages and 10 days later, a total of 3 times.

  2. Study on the Selection,Identification and Its Active Substances of A Biocontroi Bacterium against Tobacco Bacterial Wilt%1株抑烟草青枯病生防菌的筛选·鉴定及其活性物质研究

    Institute of Scientific and Technical Information of China (English)

    董昆明; 陈亮; 周晓见; 靳翠丽; 缪莉

    2011-01-01

    [Objective]The paper was to study the selection,identification and its active substances of a biocontrol bacterium against tobacco bacterial wilt. [Method]The strain was isolated from the soil of tobacco cultivation region in Qianjiang by using serial dilution method and spread-plate method. The strain's active substances were studied by TLC,silica gel column chromatography and HPLC. [ Result] A strain marked as 5B18 was isolated and proved to have significant antagonism to Ralstonia Solancearum. The whole cell fatty acid and 16SrDNA analysis indicated the strain was Bacillus amyloliquefaciens. Analysis of the strain extract showed that the extract was a complicated mixture of 13 different compounds. [ Conclusion] The research could provide theoretical foundation for the control of tobacco bacterial wilt from the perspective of microbiology.%[目的]对1株抑烟草青枯病生防菌进行筛选、鉴定和活性物质研究.[方法]采用系列稀释法和平板涂布法从黔江烟区土壤申分离得到菌株,并通过薄层层析、硅胶柱层析、HPLC等手段对其活性物质进行研究.[结果]分离得到1株编号为5B18的菌株,其对烟草青枯病病原菌(Ralstonia Solancearum)有强烈拮抗作用.全细胞脂肪酸及16SrDNA分析结果表明,该菌为解淀粉芽孢杆菌(Bacillus amyloliquefaciens).对该菌提取物分析表明,该提取物为13种不同的化合物组成的混合物.[结论]该研究为从微生物角度防治烟草青枯病提供理论基础.

  3. 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

  4. Effect of Inoculating Bacillus subtilis X-4 on Ralstonia solanacearum in Soil and Controlling Tomato Bacterial Wilt%枯草芽孢杆菌X-4对土壤青枯菌消长变化及防病效果的影响

    Institute of Scientific and Technical Information of China (English)

    肖相政; 刘可星; 廖宗文; 杜建军

    2011-01-01

    为研究枯草芽孢杆菌X-4在土壤中的定殖动态对青枯菌消长变化的影响,以及对番茄青枯病的防治效果,采用绿色荧光蛋白基因标记法,通过番茄盆栽试验直接测定了其在土壤中的定殖效果及对青枯病病原菌数量、土壤微生物功能多样性及生物量的影响.结果表明,通过绿色荧光蛋白基因标记法能成功跟踪菌株X-4在土壤中的定殖状况,其定殖曲线表现为一非对称抛物线,前期缓慢上升,24d达到高峰,当接种量为5.0×105、1.0×106CFU/(g土)时,其定殖峰值分别为2.98×107CFU/(g土)和5.03×107CFU/(g土),而青枯菌数量则呈现出与X-4相应的消长变化,处理土壤青枯菌数量在12~30d时段内呈现下降的趋势,而对照病菌数量处于较高水平并且还有上升趋势,因此未接种菌株X-4处理发病早,病指高;接种微生物菌剂X-4对土壤微生物功能多样性无不利影响,并能有效地抑制病菌,对番茄青枯病表现出明显的防治效果,接种量为1.0× 106CFU/(g土)时,35、45、55 d对青枯病的防效分别为100%、83.3%和57.2%;接种X-4还能促进番茄植株生长,增加生物量,促进结果.绿色荧光蛋白标记法可为枯草芽孢杆菌X-4在土壤中的动态变化提供直接的菌量数据,其数量与土壤中青枯菌数量的消长动态对番茄青枯病的防治效果有重要影响.%The effect of inoculating Bacillus subtilis X-4 on Ralstonia solanacearum in soil and controlling tomato bacterial wilt were studied using green fluorescent protein (gfp) marking method. The results indicated that the colonization of X-4 in soil could be tracked successfully by gfp marking, and the colonization curve presented an asymmetric parabola, as the amount increased slowly in the prophase and reached the highest point in the 24th day. The peak values were 2.98×107 CFU/ g and 5.03×107 CFU/g dry soils respectively when inoculating X-4 at the dosage of 5.0×103 and 1.0×106 CFU/g fresh

  5. 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

    2016-06-01

    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.

  6. Wilting and biological additive effect on in situ degradability and chemical composition of Arachis pintoi cv Belomonte silage

    Directory of Open Access Journals (Sweden)

    Rosana Aparecida Possenti

    2010-01-01

    Full Text Available The purpose of this work was to evaluate the effect of wilting and biological additive amendment on chemical composition, fermentation and ruminal degradability of Arachis pintoi cv Belmonte silage. The following treatments were analysed: T1- Arachis pintoi cv Belmonte fresh forage; T2 - Arachis pintoi cv Belmonte fresh forage plus bacterial additive added to the forage prior to the ensilage; T3- Arachis pintoi cv Belmonte wilted by the sun for 4 hours; T4- Arachis pintoi cv Belmonte wilted by the sun plus bacterial additive. The degradability assay was carried out using three rumen-fistuled steers. The biological additive did not affect the chemical composition of silages, in situ degradability of nutrients DM, NDF and CP and of silage fermentation. However, the wilting treatments of the silages increased DM, CP, hemicelulose and decreased N-NH3 concentration, pH value, degradability of soluble fraction “a” from DM NDF and CP. The analysed characteristics suggest that Arachis pintoi cv Belmonte could satisfactorily preserve the forage quality if wilted by the sun during 4 hours, after harvested.

  7. ldentification and Control Methods of Eggplant Bacterial Wilt, Soft Rot, Necrotic Leaf Spot, Mo-saic Virus, Root-knot Ne-matode Disease, Sun-scald, Leaf Scorch and Dehiscent Fruit%茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的识别与防治

    Institute of Scientific and Technical Information of China (English)

    郑丹丹; 张杨林

    2012-01-01

    介绍了茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的危害症状、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 bacterial wilt, soft rot, necrotic leaf spot, mosaic virus, root-knot nematode disease, sunscald, leaf scorch and dehiscent fruit were in-troduced. Then the integrated control methods were put forward, which con-tained measures of agricultural control, chemical control and so on.

  8. Biological control of fusarial wilt of pigeon pea by Bacillus brevis.

    Science.gov (United States)

    Bapat, S; Shah, A K

    2000-02-01

    A virulent strain of pigeon pea wilt pathogen was isolated from wilted pigeon pea plants and was identified as Fusarium oxysporum f. sp. udum. Many bacterial cultures showing antagonism to the pathogen were isolated from various ecological niches. When tested under pot and field conditions, development of fusarial wilt symptoms was prevented in pigeon pea seeds treated with one such antagonist, Bacillus brevis. A formulation of B. brevis with vermiculite as a carrier had a shelf life of at least 6 months. Bacillus brevis produced an extracellular antagonistic substance which induced swelling of the pathogen's hyphal tips, and cells were bulbous and swollen with shrunken and granulated cytoplasm. The antagonistic substance also inhibited germination of conidia, and was fungicidal to the vegetative mycelia of the pathogen. Comparison of the properties of our antagonistic substance with that of known antibiotics produced by B. brevis suggests that our antagonistic substance is a novel compound. The observations reported here indicate that this strain of B. brevis may have potential as a biocontrol agent against fusarial wilt in pigeon pea.

  9. Extracellular chitinases of fluorescent pseudomonads antifungal to Fusarium oxysporum f. sp. dianthi causing carnation wilt.

    Science.gov (United States)

    Ajit, Naosekpam Singh; Verma, Rajni; Shanmugam, V

    2006-04-01

    Vascular wilt of carnation caused by Fusarium oxysporum f. sp. dianthi (Prill. & Delacr.) W. C. Synder & H.N. Hans inflicts substantial yield and quality loss to the crop. Mycolytic enzymes such as chitinases are antifungal and contribute significantly to the antagonistic activity of fluorescent pseudomonads belonging to plant-growth-promoting rhizobacteria. Fluorescent pseudomonads antagonistic to the vascular wilt pathogen were studied for their ability to grow and produce chitinases on different substrates. Bacterial cells grown on chitin-containing media showed enhanced growth and enzyme production with increased anti-fungal activity against the pathogen. Furthermore, the cell-free bacterial culture filtrate from chitin-containing media also significantly inhibited the mycelial growth. Both the strains and their cell-free culture filtrate from chitin-amended media showed the formation of lytic zones on chitin agar, indicating chitinolytic ability. Extracellular proteins of highly antagonistic bacterial strain were isolated from cell-free extracts of media amended with chitin and fungal cell wall. These cell-free conditioned media contained one to seven polypeptides. Western blot analysis revealed two isoforms of chitinase with molecular masses of 43 and 18.5 kDa. Further plate assay for mycelial growth inhibition showed the 43-kDa protein to be antifungal. The foregoing studies clearly established the significance of chitinases in the antagonism of fluorescent pseudomonads, showing avenues for possible exploitation in carnation wilt management.

  10. Oak wilting in Slovakia. [Ophiostoma; ceratocystis

    Energy Technology Data Exchange (ETDEWEB)

    Lecontovyc, R.; Capek, M.

    1987-03-01

    Wilt disease, a tracheomykosis, is triggered and spread by a complex of detrimental factors involving both natural and anthropogenic environmental influences. These developments and their impact on the health of the oaks are discussed separately. The inadequate water supply, which has multiple causes, leads to outbreaks of phytophagous and xylophagus insect pests; these insects predispose the oak stands to mycosis infection and may even function as vectors. Oak wilt disease-causing fungi of the genera Ophiostoma/Ceratocystis are listed and their different effect on the various oak species as well as measures to combat them presented.

  11. 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...

  12. Restricted spread of tomato spotted wilt virus

    NARCIS (Netherlands)

    Maris, P.C.; Joosten, N.N.; Goldbach, R.W.; Peters, D.

    2003-01-01

    Spread of Tomato spotted wilt virus (TSWV) and population development of its vector Frankliniella occidentalis were studied on the pepper accessions CPRO-1 and Pikante Reuzen, which are resistant and susceptible to thrips, respectively. Viruliferous thrips were released on plants of each accession (

  13. 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.

  14. Ralstonia solanacearum extracellular polysaccharide is a specific elicitor of defense responses in wilt-resistant tomato plants.

    Directory of Open Access Journals (Sweden)

    Annett Milling

    Full Text Available Ralstonia solanacearum, which causes bacterial wilt of diverse plants, produces copious extracellular polysaccharide (EPS, a major virulence factor. The function of EPS in wilt disease is uncertain. Leading hypotheses are that EPS physically obstructs plant water transport, or that EPS cloaks the bacterium from host plant recognition and subsequent defense. Tomato plants infected with R. solanacearum race 3 biovar 2 strain UW551 and tropical strain GMI1000 upregulated genes in both the ethylene (ET and salicylic acid (SA defense signal transduction pathways. The horizontally wilt-resistant tomato line Hawaii7996 activated expression of these defense genes faster and to a greater degree in response to R. solanacearum infection than did susceptible cultivar Bonny Best. However, EPS played different roles in resistant and susceptible host responses to R. solanacearum. In susceptible plants the wild-type and eps(- mutant strains induced generally similar defense responses. But in resistant Hawaii7996 tomato plants, the wild-type pathogens induced significantly greater defense responses than the eps(- mutants, suggesting that the resistant host recognizes R. solanacearum EPS. Consistent with this idea, purified EPS triggered significant SA pathway defense gene expression in resistant, but not in susceptible, tomato plants. In addition, the eps(- mutant triggered noticeably less production of defense-associated reactive oxygen species in resistant tomato stems and leaves, despite attaining similar cell densities in planta. Collectively, these data suggest that bacterial wilt-resistant plants can specifically recognize EPS from R. solanacearum.

  15. 作物青枯病植物疫苗工程菌FJAT-T8发酵过程生长适合度研究%Growth Fitness in Fermentation Process of FJAT-T8, an Avirulent Ralstonia Aolanacearum Used as Plant Vaccine Against Crop Bacterial wilt Disease

    Institute of Scientific and Technical Information of China (English)

    陈燕萍; 刘波; 葛慈斌; 朱育菁; 肖荣凤; 史怀

    2012-01-01

    采用50 L全自动发酵罐进行植物疫苗工程菌FJAT-T8发酵,并对发酵过程的相关参数进行跟踪检测.为了研究FJAT-T8的生长适合度,将发酵过程中变化差异显著的参数作为指标进行聚类分析;同时,用多元线性回归及相关法分析各参数动态模型及因子间关系,并用电镜扫描法跟踪菌体形态变化.研究结果表明:菌体生长可划分为4个周期:0~16 h(适应期)、24 h(对数期)、32~72 h(稳定期)和80~96 h(消亡期);该菌发酵最佳质量的终止判断指标为:发酵时间40~48 h,发酵液pH值8.7~8.8,溶氧量趋于稳定不变.%The paper dealt with the fermentation technique of an avirulent Ralstonia solanacearum strain FJAT-T8, which was used as plant vaccine against crop bacterial wilt disease. The fermentation process of FJAT-T8 was investigated by determination of on-line and off-line parameters in 50L automatic fermentation container. In order to study the growth fitness of FJAT-T8. the parameters with significantly variation during fermentation process were served as indexes and analyzed with cluster analysis. The multiple linear regression and correlation analysis were also used to analysis the parameter dynamic model and relationship between fermentation factors. Besides, tracing observation of cell morphology was conducted with electron microscope. The results showed that the cell growth cycle of FJAT-T8 could be divided into four periods: 0?16h (adaptation period). 24h (logarithmic period), 32 ?72h (stationary period) and 80 ~ 96h (decline period) . The comprehensive evaluation indexes for the best fermentation quality werei fermentation time of 40 ?8h, fermentation pH of 8. 7 ?. 8 and the dissolved oxygen maintaining steady. The study would improve the fermentation quality, formation of product quality standards and factory production of plant vaccine strain T8.

  16. 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...

  17. Insertional mutagenesis in the vascular wilt pathogen Verticillium dahliae

    NARCIS (Netherlands)

    Santhanam, P.

    2014-01-01

    Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. The ascomycete fungus Verticillium dahliae causes vascular wilt diseases in hundreds of dicotyledonous plant species, including important crops such as eggplant, lettuce, olive, spinach

  18. Ambrosia beetles associated with laurel wilt of avocado

    Science.gov (United States)

    Redbay ambrosia beetle, Xyleborus glabratus, 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 trees in the family Lauraceae. Laurel wilt has since spr...

  19. 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.

  20. Screening of antagonistic bacteria for biological control of nursery wilt of black pepper (Piper nigrum).

    Science.gov (United States)

    Anith, K N; Radhakrishnan, N V; Manomohandas, T P

    2003-01-01

    Bacterial antagonists of Phytophthora capsici were isolated from underground shoot portions of rooted cuttings of black pepper. Initially isolates were screened by dual culture on potato dextrose agar and carrot agar. Further, a screening was done on black pepper shoots for supression of lesion caused by the pathogen. Most of the antagonists showed varying levels of antagonism in the dual culture and the shoot assay. Isolate PN-026, showing the highest suppression of lesion development in the shoot assay was found to be the most efficient antagonist in reducing Phytophthora capsici induced nursery wilt of black pepper. This screening involving the host, pathogen, and the antagonist, performed on black pepper shoot (the planting material for this vegetatively propagated crop), could be used as a rapid and reliable method for the isolation of efficient bacterial antagonists of P. capsici.

  1. The influence of different concentrations of bio-organic fertilizer on cucumber Fusarium wilt and soil microflora alterations

    Science.gov (United States)

    Huang, Nan; Wang, Weiwei; Yao, Yanlai; Zhu, Fengxiang; Wang, Weiping; Chang, Xiaojuan

    2017-01-01

    Fusarium wilt is one of the main diseases of cucumber, and bio-organic fertilizer has been used to control Fusarium wilt. In this study, a pot experiment was conducted to evaluate the effects of bio-organic fertilizer applied at four levels on the suppression of Fusarium wilt disease in cucumber, the soil physico-chemical properties and the microbial communities. In comparison with the control (CK), low concentrations of bio-organic fertilizer (BIO2.5 and BIO5) did not effectively reduce the disease incidence and had little effect on soil microorganisms. High concentrations of bio-organic fertilizer (BIO10 and BIO20) significantly reduced the disease incidence by 33.3%-66.7% and the production was significantly improved by 83.8%-100.3%. The soil population of F. oxysporum f. sp. cucumerinum was significantly lower in bio-organic fertilizer treatments, especially in BIO10 and BIO20. The microorganism activity increased with the bio-organic fertilizer concentration. High-throughput sequencing demonstrated that, at the order level, Sphingomonadales, Bacillales, Solibacterales and Xylariales were significantly abundant in BIO10 and BIO20 soils. At the genus level, the abundance and composition of bacterial and fungal communities in BIO10 and BIO20 were similar, illustrating that high concentrations of bio-organic fertilizer activated diverse groups of microorganisms. Redundancy analysis (RDA) showed that Xanthomonadales, Sphingomonadales, Bacillales, Orbiliales, Sordariales, and Mucorales occurred predominantly in the BIO10 and BIO20. These microorganisms were related to the organic matter, available potassium and available phosphorus contents. In conclusion, a high concentration of bio-organic fertilizer application suppressed the Fusarium wilt disease and increased cucumber production after continuous cropping might through improving soil chemical condition and manipulating the composition of soil microbial community. PMID:28166302

  2. The influence of different concentrations of bio-organic fertilizer on cucumber Fusarium wilt and soil microflora alterations.

    Science.gov (United States)

    Huang, Nan; Wang, Weiwei; Yao, Yanlai; Zhu, Fengxiang; Wang, Weiping; Chang, Xiaojuan

    2017-01-01

    Fusarium wilt is one of the main diseases of cucumber, and bio-organic fertilizer has been used to control Fusarium wilt. In this study, a pot experiment was conducted to evaluate the effects of bio-organic fertilizer applied at four levels on the suppression of Fusarium wilt disease in cucumber, the soil physico-chemical properties and the microbial communities. In comparison with the control (CK), low concentrations of bio-organic fertilizer (BIO2.5 and BIO5) did not effectively reduce the disease incidence and had little effect on soil microorganisms. High concentrations of bio-organic fertilizer (BIO10 and BIO20) significantly reduced the disease incidence by 33.3%-66.7% and the production was significantly improved by 83.8%-100.3%. The soil population of F. oxysporum f. sp. cucumerinum was significantly lower in bio-organic fertilizer treatments, especially in BIO10 and BIO20. The microorganism activity increased with the bio-organic fertilizer concentration. High-throughput sequencing demonstrated that, at the order level, Sphingomonadales, Bacillales, Solibacterales and Xylariales were significantly abundant in BIO10 and BIO20 soils. At the genus level, the abundance and composition of bacterial and fungal communities in BIO10 and BIO20 were similar, illustrating that high concentrations of bio-organic fertilizer activated diverse groups of microorganisms. Redundancy analysis (RDA) showed that Xanthomonadales, Sphingomonadales, Bacillales, Orbiliales, Sordariales, and Mucorales occurred predominantly in the BIO10 and BIO20. These microorganisms were related to the organic matter, available potassium and available phosphorus contents. In conclusion, a high concentration of bio-organic fertilizer application suppressed the Fusarium wilt disease and increased cucumber production after continuous cropping might through improving soil chemical condition and manipulating the composition of soil microbial community.

  3. 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.

  4. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    NARCIS (Netherlands)

    Haan, de P.; Ultzen, T.; Prins, M.; Gielen, J.; Goldbach, R.; Grinsven, van M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can

  5. Analysis of tomato spotted wilt virus genome transcription

    NARCIS (Netherlands)

    Knippenberg, van I.C.

    2005-01-01

    Tomato spotted wilt virus (TSWV) is the type species of the genus Tospovirus within the Bunyaviridae, a family of segmented negative strand RNA viruses. Although much ground has been covered in the past two decades, many questions concerning the mechanism of replication and transcription of this imp

  6. 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...

  7. 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...

  8. 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.

  9. Evaluation of Streptomyces spp. against Fusarium oxysporum f. sp. ciceris for the management of chickpea wilt

    Directory of Open Access Journals (Sweden)

    Amini Jahanshir

    2016-07-01

    Full Text Available In this study, about 112 isolates of Streptomyces were isolated from chickpea rhizospheric soils. Among the isolated strains, five showed strong inhibitory effects against chickpea Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris in vitro using plate assay and selected for further studies. The selected strains were identified as Streptomyces spp. based on morphological and biochemical characterization as well as 16S rDNA sequences analysis. Our results assigned them to strains related to genus of Streptomyces. In vitro, antagonistic effects of Streptomyces strains against the disease were evaluated through the dual-culture method, volatile and non-volatile metabolites, siderophore, protease and chitinase production. All bacterial strains inhibited mycelial growth of the pathogen ranging from 26 to 44.2% in dual culture assay. The non-volatile extract of five of the Streptomyces strains inhibited more than 50% growth of the pathogen, whereas volatile compounds were less effective on mycelial growth inhibition (20.2 to 33.4%. The ability of the biocontrol agents to produce siderophore and protease were varied, whereas, production of chitinase was detected for all strains. Results of the greenhouse assay indicated that all biocontrol agents reduced disease severity (ranging from 38.7 to 54.8%. Accordingly, strain KS62 showed higher control efficacy (54.8%. In addition, the biomass of chickpea plants (plant height and dry weight significantly increased in plants treated with Streptomyces strains compared to non-bacterized control. The results of this study showed that it may be possible to manage chickpea Fusarium wilt disease effectively by using Streptomyces species, as biocontrol agents. Therefore, evaluating their efficiency under field conditions is needed.

  10. Mathematical analysis of dynamic spread of Pine Wilt disease.

    Science.gov (United States)

    Dimitrijevic, D D; Bacic, J

    2013-01-01

    Since its detection in Portugal in 1999, the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer), a causal agent of Pine Wilt Disease, represents a threat to European forestry. Significant amount of money has been spent on its monitoring and eradication. This paper presents mathematical analysis of spread of pine wilt disease using a set of partial differential equations with space (longitude and latitude) and time as parameters of estimated spread of disease. This methodology can be used to evaluate risk of various assumed entry points of disease and make defense plans in advance. In case of an already existing outbreak, it can be used to draw optimal line of defense and plan removal of trees. Optimization constraints are economic loss of removal of susceptible trees as well as budgetary constraints of workforce cost.

  11. Venation Skeleton-Based Modeling Plant Leaf Wilting

    Directory of Open Access Journals (Sweden)

    Shenglian Lu

    2009-01-01

    Full Text Available A venation skeleton-driven method for modeling and animating plant leaf wilting is presented. The proposed method includes five principal processes. Firstly, a three-dimensional leaf skeleton is constructed from a leaf image, and the leaf skeleton is further used to generate a detailed mesh for the leaf surface. Then a venation skeleton is generated interactively from the leaf skeleton. Each vein in the venation skeleton consists of a segmented vertices string. Thirdly, each vertex in the leaf mesh is banded to the nearest vertex in the venation skeleton. We then deform the venation skeleton by controlling the movement of each vertex in the venation skeleton by rotating it around a fixed vector. Finally, the leaf mesh is mapped to the deformed venation skeleton, as such the deformation of the mesh follows the deformation of the venation skeleton. The proposed techniques have been applied to simulate plant leaf surface deformation resulted from biological responses of plant wilting.

  12. Transgenic tomato hybrids resistant to tomato spotted wilt virus infection.

    OpenAIRE

    Haan, de, A.; Ultzen, T.; Prins, M.; Gielen, J; Goldbach, R; Grinsven, van, J.J.M.

    1996-01-01

    Tomato spotted wilt virus (TSWV) infections cause significant economic losses in the commercial culture of tomato (Lycopersicon esculentum). Culture practices have only been marginally effective in controlling TSWV. The ultimate way to minimize losses caused by TSWV is resistant varieties. These can be obtained by introgression of natural sources of resistance from wild relatives or by expressing viral sequences in transgenic tomato plants. We report high levels of resistance to TSWV obtained...

  13. 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

    2016-04-21

    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.

  14. An evaluation of the wilt-causing bacterium Ralstonia solanacearum as a potential biological control agent for the alien Kahili ginger (Hedychium gardnerianum) in Hawaiian forests

    Science.gov (United States)

    1999-01-01

    Kahili ginger (Hedychium gardnerianum) is an invasive weed in tropical forests in Hawaii and elsewhere. Bacterial wilt caused by the ginger strain of Ralstonia(=Pseudomonas) solanacearum systemically infects edible ginger (Zingiber officinale) and ornamental gingers (Hedychium spp.), causing wilt in infected plants. The suitability of R. solanacearum as a biological control agent for kahili ginger was investigated by inoculating seedlings and rooted cuttings of native forest plants, ornamental ginger, and solanaceous species to confirm host specificity. Inoculation via stem injection or root wounding with a bacterial–water suspension was followed by observation for 8 weeks. Inoculations on H. gardnerianum were then carried out in ohia-lehua (Metrosideros polymorpha) wet forests of Hawaii Volcanoes National Park to determine the bacterium's efficacy in the field. No native forest or solanaceous species developed wilt or other symptoms during the study. The bacterium caused limited infection near the inoculation site on H. coronarium, Z. zerumbet, Heliconia latispatha, and Musa sapientum. However, infection did not become systemic in any of these species, and normal growth resumed following appearance of initial symptoms. All inoculated H. gardnerianum plants developed irreversible chlorosis and severe wilting 3–4 weeks following inoculation. Systemic infection also caused death and decay of rhizomes. Most plants were completely dead 16–20 weeks following inoculation. The destructiveness of the ginger strain of R. solanacearum to edible ginger has raised questions regarding its use for biological control. However, because locations of kahili ginger infestations are often remote, the risk of contaminating edible ginger plantings is unlikely. The ability of this bacterium to cause severe disease in H. gardnerianum in the field, together with its lack of virulence in other ginger species, contributes to its potential as a biological control agent.

  15. 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...

  16. Genetic dissection of Verticillium wilt resistance mediated by tomato Ve1

    NARCIS (Netherlands)

    Fradin, E.F.; Zhang, Z.; Juarez Ayala, J.C.; Castroverde, C.C.M.; Nazar, R.N.; Robb, J.; Liu, Chun-Ming; Thomma, B.P.H.J.

    2009-01-01

    Vascular wilt diseases caused by soil-borne pathogens are among the most devastating plant diseases worldwide. The Verticillium genus includes vascular wilt pathogens with a wide host range. Although V. longisporum infects various hosts belonging to the Cruciferaceae, V. dahliae and V. albo-atrum ca

  17. Physiology of host-pathogen interaction in wilt diseases of cotton in relation to pathogen management

    Science.gov (United States)

    Verticillium and Fusarium wilts are important vascular wilt diseases of cotton that significantly reduce cotton yields and negatively impact fiber quality. In spite of intense efforts to control these diseases, yield losses persist and in the US alone were estimated to be about 133 and 28 thousand b...

  18. 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.

  19. 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.

  20. Environmental Influences on Pigeonpea-Fusarium udum Interactions and Stability of Genotypes to Fusarium Wilt.

    Science.gov (United States)

    Sharma, Mamta; Ghosh, Raju; Telangre, Rameshwar; Rathore, Abhishek; Saifulla, Muhammad; Mahalinga, Dayananda M; Saxena, Deep R; Jain, Yogendra K

    2016-01-01

    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 at identifying and validating resistant genotypes to fusarium wilt and determining the magnitude of genotype × environment (G × E) interactions through multi-environment and multi-year screening. A total of 976 genotypes including germplasm and breeding lines were screened against wilt using wilt sick plot at Patancheru, India. Ninety two genotypes resistant to wilt were tested for a further two years using wilt sick plot at Patancheru. A Pigeonpea Wilt Nursery (PWN) comprising of 29 genotypes was then established. 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 were examined by biplot which partitioned the main effect into G, E, and G × E interactions with significant levels (p ≤ 0.001) being obtained for wilt incidence. The genotype contributed 36.51% of resistance variation followed by the environment (29.32%). A GGE biplot integrated with a 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 programs.

  1. Changes induced by Trichoderma harzianum in suppressive compost controlling Fusarium wilt.

    Science.gov (United States)

    Blaya, Josefa; López-Mondéjar, Rubén; Lloret, Eva; Pascual, Jose Antonio; Ros, Margarita

    2013-09-01

    The addition of species of Trichoderma to compost is a widespread technique used to control different plant diseases. The biological control activity of these species is mainly attributable to a combination of several mechanisms of action, which may affect the microbiota involved in the suppressiveness of compost. This study was therefore performed to determine the effect of inoculation of Trichoderma harzianum (T. harzianum) on compost, focusing on bacterial community structure (16S rRNA) and chitinase gene diversity. In addition, the ability of vineyard pruning waste compost, amended (GCTh) or not (GC) with T. harzianum, to suppress Fusarium wilt was evaluated. The addition of T. harzianum resulted in a high relative abundance of certain chitinolytic bacteria as well as in remarkable protection against Fusarium oxysporum comparable to that induced by compost GC. Moreover, variations in the abiotic characteristics of the media, such as pH, C, N and iron levels, were observed. Despite the lower diversity of chitinolytic bacteria found in GCTh, the high relative abundance of Streptomyces spp. may be involved in the suppressiveness of this growing media. The higher degree of compost suppressiveness achieved after the addition of T. harzianum may be due not only to its biocontrol ability, but also to changes promoted in both abiotic and biotic characteristics of the growing media.

  2. 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...

  3. First Report on Fusarium Wilt of Zucchini Caused by Fusarium oxysporum, in Korea.

    Science.gov (United States)

    Choi, In-Young; Kim, Ju-Hee; Lee, Wang-Hyu; Park, Ji-Hyun; Shin, Hyeon-Dong

    2015-06-01

    Fusarium wilt of zucchini in Jeonju, Korea, was first noticed in May 2013. Symptoms included wilting of the foliage, drying and withering of older leaves, and stunting of plants. Infected plants eventually died during growth. Based on morphological characteristics and phylogenetic analyses of the molecular markers (internal transcribed spacer rDNA and translation elongation factor 1α), the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was demonstrated via artificial inoculation, and it satisfied Koch's postulates. To our knowledge, this is the first report of F. oxysporum causing wilt of zucchini in Korea.

  4. 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...

  5. 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.

  6. In vitro rumen simulated (RUSITEC) metabolism of freshly cut or wilted grasses with contrasting polyphenol oxidase activities

    OpenAIRE

    2011-01-01

    The study investigated in vitro simulated rumen metabolism of freshly cut and wilted cocksfoot [Dactylis glomerata; high polyphenol oxidase (PPO)] and tall fescue (Festuca arundinacea; low PPO). A 16-vessel RUSITEC was used with the four treatment combinations: cocksfoot wilted (C(w)); cocksfoot fresh (C(f)); tall fescue wilted (TF(w)) and tall fescue fresh (TF(f)). Rumen liquor was collected from four fistulated dairy cows maintained on permanent pasture. The experiment ran for 12 d with sam...

  7. 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

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

    Directory of Open Access Journals (Sweden)

    Ana I de Castro

    Full Text Available 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

  9. Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping.

    Science.gov (United States)

    Santhanam, Rakesh; Luu, Van Thi; Weinhold, Arne; Goldberg, Jay; Oh, Youngjoo; Baldwin, Ian T

    2015-09-01

    Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant's native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to a Fusarium-Alternaria disease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem for N. attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems.

  10. Effect of plant essential oils on Ralstonia solanacearum race 4 causing bacterial wilt of edible ginger

    Science.gov (United States)

    Palmarosa (Cymbopogon martini), lemongrass (C. citratus) and eucalyptus (Eucalyptus globulus) oils were investigated for their effects on Ralstonia solanacearum race 4, and their potential use as bio-fumigants for treating pathogen- infested edible ginger (Zingiber officinale R.) fields. Three conce...

  11. 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...

  12. 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%.

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

    Directory of Open Access Journals (Sweden)

    Koste eYadeta

    2013-04-01

    Full Text Available 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 and biological measures to control this group of plant pathogens are generally ineffective, and the most effective control strategy is the use of genetic resistance. Owing to the fact that vascular wilt pathogens live deep in the interior of their host plants, studies into the biology of vascular pathogens are complicated. However, to design novel strategies to combat vascular wilt diseases, understanding the (molecular biology of vascular pathogens and the molecular mechanisms underlying plant defense against these pathogens is crucial. In this review we discuss the current knowledge on interactions of vascular wilt pathogens with their host plants, with emphasis on host defense responses against this group of pathogens.

  14. 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.

  15. Cotton GhBAK1 Mediates Verticillium Wilt Resistance and Cell Death

    Institute of Scientific and Technical Information of China (English)

    Xiquan Gao; Fangjun Li; Maoying Li; Ali S.Kianinejad; Jane K.Dever; Terry A.Wheeler; Zhaohu LP

    2013-01-01

    Virus-induced gene silencing (VIGS) offers a powerful approach for functional analysis of individual genes by knocking down their expression.We have adopted this approach to dissect gene functions in cotton resistant to Verticillium wilt,one of the most devastating diseases worldwide.We showed hera that highly efficient VIGS was obtained in a cotton breeding line (CA4002) with partial resistance to Verticillium wilt,and GhMKK2 and Gh Ve 1 are required for its resistance to Verticillium wilt.Arabidopsis AtBAK1/SERK3,a central regulator in plant disease resistance,belongs to a subfamily of somatic embryogenesis receptor kinases (SERKs) with five members,AtSERK1 to AtSERK5.Two BAK1 orthologs and one SERK1 ortholog were identified in the cotton genome.Importantly,GhBAK1 is required for CA4002 resistance to Verticillium wilt.Surprisingly,silencing of GhBAK1 is sufficient to trigger cell death accompanied with production of reactive oxygen species in cotton.This result is distinct from Arabidopsis in which AtBAK1 and AtSERK4 play redundant functions in cell death control.Apparently,cotton has only evolved SERK1 and BAK1 whereas AtSERK4/5 are newly evolved genes in Arabidopsis.Our studies indicate the functional importance of BAK1 in Verticillium wilt resistance and suggest the dynamic evolution of SERK family members in different plant species.

  16. Design and development of a DNA array for rapid detection and identification of tomato vascular wilt pathogens

    NARCIS (Netherlands)

    Lievens, B.; Brouwer, M.; Vanachter, A.C.R.C.; Lévesque, C.A.; Cammue, B.P.A.; Thomma, B.P.H.J.

    2003-01-01

    Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici, and Verticillium wilt, caused by either Verticillium albo-atrum or Verticillium dahliae, are devastating diseases of tomato (Lycopersicon esculentum) found worldwide. Monitoring is the cornerstone of integrated pest management of any di

  17. Meta-analysis to refine map position and reduce confidence intervals for delayed canopy wilting QTLs in soybean

    Science.gov (United States)

    Slow canopy wilting in soybean has been identified as a potentially beneficial trait for ameliorating drought effects on yield. Previous research identified QTLs for slow wilting from two different bi-parental populations and this information was combined with data from three other populations to id...

  18. Development of secondary pine forests after pine wilt disease in western Japan

    Energy Technology Data Exchange (ETDEWEB)

    Fujihara, Michiro [Natural History Museum and Inst., Chiba (Japan)

    1996-10-01

    The development of secondary Pinus densiflora (Japanese red pine) forests after pine wilt disease was studied through phytosociological analysis, estimation of forest structure before disease and size-structure, tree ring and stem analyses. Following the end of the disease, the growth of previously suppressed small oak trees was accelerated. This is quite different from the development of forests following fire, which starts with the establishment of pine seedlings. Pine wilt disease shifted the dominance of secondary forests from Pinus densiflora to Quercus serrata oak forest. In pine forests, disturbance by fire is important for forest maintenance. In contrast, disturbance by pine wilt disease leads to an acceleration of succession from pine forest to oak forest. 50 refs, 3 figs, 2 tabs

  19. 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.

  20. Evaluation of Alternatives to Carbamate and Organophosphate Insecticides Against Thrips and Tomato Spotted Wilt Virus in Peanut Production.

    Science.gov (United States)

    Marasigan, K; Toews, M; Kemerait, R; Abney, M R; Culbreath, A; Srinivasan, R

    2016-04-01

    Thrips are important pests of peanut. They cause severe feeding injuries on peanut foliage in the early season. They also transmit Tomato spotted wilt virus (TSWV), which causes spotted wilt disease. At-plant insecticides and cultivars that exhibit field resistance to TSWV are often used to manage thrips and spotted wilt disease. Historically, peanut growers used the broad-spectrum insecticides aldicarb (IRAC class 1A; Temik) and phorate (IRAC class 1B; Thimet) for managing thrips and thereby reducing TSWV transmission. Aldicarb has not been produced since 2011 and its usage in peanut will be legally phased out in 2018; therefore, identification of alternative chemistries is critical for thrips and spotted wilt management. Here, eight alternative insecticides, with known thrips activity, were evaluated in field trials conducted from 2011 through 2013. In addition, different application methods of alternatives were also evaluated. Imidacloprid (Admire Pro), thiamethoxam (Actara), spinetoram (Radiant), and cyantraniliprole (Exirel) were as effective as aldicarb and phorate in suppressing thrips, but none of the insecticides significantly suppressed spotted wilt incidence. Nevertheless, greenhouse assays demonstrated that the same alternative insecticides were effective in suppressing thrips feeding and reducing TSWV transmission. Spotted wilt incidence in the greenhouse was more severe (∼80%) than in the field (5–25%). In general, field resistance to TSWV in cultivars only marginally influenced spotted wilt incidence. Results suggest that effective management of thrips using alternative insecticides and subsequent feeding reduction could improve yields under low to moderate virus pressure.

  1. 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 ...

  2. Functional analysis of the tomato Ve resistance locus against Verticillium wilt

    NARCIS (Netherlands)

    Fradin, E.F.

    2011-01-01

    Verticillium dahliae, V. albo-atrum and V. longisporum are soil-borne plant pathogens that are responsible for Verticillium wilt diseases in temperate and subtropical regions. Collectively they can infect over 200 hosts, including many economically important crops. Chapter 1 is a “pathogen pro

  3. Western flower thrips can transmit Tomato spotted wilt virus from infected tomato fruits

    Science.gov (United States)

    Tomato spotted wilt virus (TSWV) has long been known to spread via plant propagation materials including transplants. Global dissemination of TSWV has also been linked to transport of thrips-infested and virus-infected horticultural and floricultural products through trade and commerce. However, th...

  4. Evaluation of thrips resistance in pepper to control Tomato spotted wilt virus infection

    NARCIS (Netherlands)

    Maris, P.C.

    2004-01-01

    The objective of this study was to analyse the effect of thrips ( F. occidentalis ) resistance in pepper ( Capsicum ) on the spread of Tomato spotted wilt virus (TSWV). Results demonstrate that the rate of primary TSWV-infection is effectively limited in a thrips-resistant (TR) pepper crop compared

  5. Genetic dissection of tetraploid cotton resistant to Verticillium wilt using interspecific chromosome segment introgression lines

    Institute of Scientific and Technical Information of China (English)

    Peng; Wang; Zhiyuan; Ning; Ling; Lin; Hong; Chen; Hongxian; Mei; Jun; Zhao; Bingliang; Liu; Xin; Zhang; Wangzhen; Guo; Tianzhen; Zhang

    2014-01-01

    Verticillium wilt(caused by the pathogen Verticillium dahliae) is of high concern for cotton producers and consumers. The major strategy for controlling this disease is the development of resistant cotton(Gossypium spp.) cultivars. We used interspecific chromosome segment introgression lines(CSILs) to identify quantitative trait loci(QTL) associated with resistance to Verticillium wilt in cotton grown in greenhouse and inoculated with three defoliating V. dahliae isolates. A total of 42 QTL, including 23 with resistance-increasing and 19 with resistancedecreasing, influenced host resistance against the three isolates. These QTL were identified and mapped on 18 chromosomes(chromosomes A1, A3, A4, A5, A7, A8, A9, A12, A13, D1, D2,D3, D4, D5, D7, D8, D11, and D12), with LOD values ranging from 3.00 to 9.29. Among the positive QTL with resistance-increasing effect, 21 conferred resistance to only one V. dahliae isolate, suggesting that resistance to V. dahliae conferred by most QTL is pathogen isolate-specific. The At subgenome of cotton had greater effect on resistance to Verticillium wilt than the Dt subgenome. We conclude that pyramiding different resistant QTL could be used to breed cotton cultivars with broad-spectrum resistance to Verticillium wilt.

  6. 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.

  7. Recovery plan for laurel wilt of avocado, caused by Raffaelea lauricola

    Science.gov (United States)

    Executive Summary Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana), an important commercial fruit crop. The disease threatens commercial production in the US and other countries, and currently impacts the avocado industry in Florida. As laurel w...

  8. 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...

  9. 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

  10. 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

  11. Identification of genetic determinants in potato for resistance to Verticillium wilt

    Science.gov (United States)

    Despite decades of research to control Verticillium wilt (VW), which is caused by the soil-borne fungal pathogens Verticillium dahliae and V. albo-atrum, this disease continues to be a recurrent problem for potato production throughout North America. It can result in yield losses of up to 50% and is...

  12. Laurel wilt in natural and agricultural ecosystems: Understanding the drivers and scales of complex pathosystems

    Science.gov (United States)

    Laurel wilt kills members of the Lauraceae plant family in the southeastern United States. It is caused by Raffaelea lauricola, a nutritional fungal symbiont of an invasive Asian ambrosia beetle, Xyleborus glabratus, which was detected in Port Wentworth, Georgia in 2002. The beetle is the primary v...

  13. Comparison of ambrosia beetle communities in two hosts 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...

  14. In vitro transcription of Tomato spotted wilt virus is independent of translation

    NARCIS (Netherlands)

    Knippenberg, van I.C.; Goldbach, R.W.; Kormelink, R.J.M.

    2004-01-01

    Ongoing transcription in vitro of Tomato spotted wilt virus (TSWV) has previously been demonstrated to require the presence of reticulocyte lysate. This dependence was further investigated by testing the occurrence of transcription in the presence of two translation inhibitors: edeine, an inhibitor

  15. Analysis of the Tomato spotted wilt virus ambisense S RNA-encoded hairpin structure in translation

    NARCIS (Netherlands)

    Geerts-Dimitriadou, C.; Lu, Y.Y.; Geertsema, C.; Goldbach, R.W.; Kormelink, R.J.M.

    2012-01-01

    The intergenic region (IR) of ambisense RNA segments from animal- and plant-infecting (-)RNA viruses functions as a bidirectional transcription terminator. The IR sequence of the Tomato spotted wilt virus (TSWV) ambisense S RNA contains stretches that are highly rich in A-residues and U-residues and

  16. 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,

  17. Bacterial Vaginosis

    Science.gov (United States)

    ... Issues > Conditions > Sexually Transmitted > Bacterial Vaginosis Health Issues Listen Español Text Size Email Print Share Bacterial Vaginosis Page Content Bacterial vaginosis (BV) is the most common vaginal infection in sexually active teenaged girls . It appears to be caused by ...

  18. [Main bacterial groups in banana soil under rotated and continuous cropping].

    Science.gov (United States)

    Ouyang, Xian; Ruan, Xiao-Lei; Wu, Chao; Bai, Ting-Ting; Li, Hua-Ping

    2011-06-01

    Banana wilt is the main disease in banana production, while banana-leek rotation can effectively control the occurrence of the disease. In order to understand the variations of soil bacterial groups under banana-leek rotation and banana continuous cropping, soil samples under these two cropping systems were collected to extract crude DNA, and the bacterial 16S rDNA in V3 region was amplified by PCR. The PCR products were then separated by DGGE, and the main different bands were sequenced and compared with the records of NCBI to identify the germs. Under banana-leek rotation, soil bacterial diversity was richer, and the main bacterial groups were Bacteroidetes, Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria; while under banana continuous cropping, the soil bacterial diversity was somewhat decreased, and the main bacterial groups were Firmicutes, Proteobacteria, Actinobacteria, and Chloroflexi.

  19. 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.

  20. 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.

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

    OpenAIRE

    Qirong eShen; Wu eXiong; Qingyun eZhao; Chao eXue; Weibing eXun; Jun eZhao; Rong eLi; Huasong eWu

    2016-01-01

    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...

  2. Comparison of Fungal Community in Black Pepper-Vanilla and Vanilla Monoculture Systems Associated with Vanilla Fusarium Wilt Disease

    OpenAIRE

    Xiong, Wu; Zhao, Qingyun; Xue, Chao; Xun, Weibing; Zhao, Jun; Wu, Huasong; Li, Rong; Shen, Qirong

    2016-01-01

    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...

  3. Potential of Endophytic Fungi Isolated from Cotton Roots for Biological Control against Verticillium Wilt Disease

    Science.gov (United States)

    Wang, Lingfei; Li, Zhifang; Shi, Yongqiang; Zhao, LiHong; Feng, Zili; Zhu, Heqin

    2017-01-01

    Verticillium wilt is a soil-borne disease, and severely limits the development of cotton production. To investigate the role of endophytic fungi on Verticillium wilt, CEF-818 (Penicillium simplicissimum), CEF-714 (Leptosphaeria sp.), CEF-642 (Talaromyces flavus.) and CEF-193 (Acremonium sp.) isolated from cotton roots were used to assess their effects against cotton wilt disease caused by a defoliating V. dahliae strain Vd080. In the greenhouse, all treatments significantly reduced disease incidence and disease index, with the control efficacy ranging from 26% (CEF-642) to 67% (CEF-818) at 25 days (d) after inoculation. In the disease nursery, compared to controls (with disease incidence of 33.8% and disease index of 31), CEF-818, CEF-193, CEF-714 and CEF-642 provided a protection effect of 69.5%, 69.2%, 54.6% and 45.7%, respectively. Especially, CEF-818 and CEF-714 still provided well protection against Verticillium wilt with 46.9% and 56.6% or 14.3% and 33.7% at the first peak of the disease in heavily infected field, respectively (in early July). These results indicated that these endophytes not only delayed but also reduced wilt symptoms on cotton. In the harvest, the available cotton bolls of plant treated with CEF-818 and CEF-714 increased to 13.1, and 12.2, respectively. And the seed cotton yield significantly increased after seed bacterization with CEF-818 (3442.04 kg/ha) compared to untreated control (3207.51 kg/ha) by 7.3%. Furtherly, CEF-818 and CET-714 treatment increased transcript levels for PAL, PPO, POD, which leads to the increase of cotton defense reactions. Our results indicate that seed treatment of cotton plants with CEF-818 and CET-714 can help in the biocontrol of V. dahliae and improve seed cotton yield in cotton fields. This study provided a better understanding of cotton-endophyte interactions which will aid in developing effective biocontrol agents for Verticillium wilt of cotton in futhre. PMID:28107448

  4. Identification of Pathogen Causing Wilt Disease of Peanut in Yicheng City%宜城市花生枯萎病病原的鉴定

    Institute of Scientific and Technical Information of China (English)

    晏立英; 温少华; 雷永; 黄家权; 蒋相国; 王圣玉; 廖伯寿

    2011-01-01

    The pathogen of peanut wilt disease in Yicheng city, Hubei province was identified by bioassay and molecular identification. The results indicated that 38 samples in 41 samples isolated in June were fungi, and among them 23 samples were Aspergillus niger. By PCR amplification and sequence analysis of ribosomal RNA ITS regions, the pathogen causing wilt disease of peanut in June were identified as A. Niger, Rizoctonia solani and Fusarium sp. In August, the main pathogen was bacteria. 9 samples were identified as Ralstonia solanacerum out of the 10 samples by typical morphological character of bacteria and symptom of peanut seedling after bacterial inoculation.%对湖北宜城花生枯萎病的病原进行了生物学和分子鉴定,结果显示,6月份的病原主要是真菌,41份样品中,分离的真菌样品有38份,其中23份样品是黑曲霉菌.通过PSA培养基上真菌形态观察、真菌核糖体间区ITS区段的PCR扩增和序列分析,明确6月份花生枯萎病的病原分别是黑曲霉菌、立枯丝核菌和镰刀菌;8月份的病原主要为细菌,10份样品中,9份分离得到茄科雷尔氏菌(青枯病菌),通过细菌的回接试验,部分植株产生典型青枯、萎蔫症状,明确8月份的病原是青枯病菌.

  5. Success evaluation of the biological control of Fusarium wilts of cucumber, banana, and tomato since 2000 and future research strategies.

    Science.gov (United States)

    Raza, Waseem; Ling, Ning; Zhang, Ruifu; Huang, Qiwei; Xu, Yangchun; Shen, Qirong

    2017-03-01

    The Fusarium wilt caused by Fusarium oxysporum strains is the most devastating disease of cucumber, banana, and tomato. The biological control of this disease has become an attractive alternative to the chemical fungicides and other conventional control methods. In this review, the research trends and biological control efficiencies (BCE) of different microbial strains since 2000 are reviewed in detail, considering types of microbial genera, inoculum application methods, plant growth medium and conditions, inoculum application with amendments, and co-inoculation of different microbial strains and how those affect the BCE of Fusarium wilt. The data evaluation showed that the BCE of biocontrol agents was higher against the Fusarium wilt of cucumber compared to the Fusarium wilts of banana and tomato. Several biocontrol agents mainly Bacillus, Trichoderma, Pseudomonas, nonpathogenic Fusarium, and Penicillium strains were evaluated to control Fusarium wilt, but still this lethal disease could not be controlled completely. We have discussed different reasons of inconsistent results and recommendations for the betterment of BCE in the future. This review provides knowledge of the biotechnology of biological control of Fusarium wilt of cucumber, banana, and tomato in a nut shell that will provide researchers a beginning line to start and to organize and plan research for the future studies.

  6. 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].

  7. 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].

  8. 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.

  9. In vitro transcription of Tomato spotted wilt virus is independent of translation

    OpenAIRE

    Knippenberg, van, B.M.; Goldbach, R.W.; Kormelink, R.J.M.

    2004-01-01

    Ongoing transcription in vitro of Tomato spotted wilt virus (TSWV) has previously been demonstrated to require the presence of reticulocyte lysate. This dependence was further investigated by testing the occurrence of transcription in the presence of two translation inhibitors: edeine, an inhibitor that still allows scanning of nascent mRNAs by the 40S ribosomal subunit, and cycloheximide, an inhibitor that completely blocks translation including ribosome scanning. Neither of these inhibitors...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Expression of genes responsible for ethylene production and wilting are differently regulated in carnation (Dianthus caryophyllus L.) petals.

    Science.gov (United States)

    Kosugi; Shibuya; Tsuruno; Iwazaki; Mochizuki; Yoshioka; Hashiba; Satoh

    2000-09-01

    Carnation petals exhibit autocatalytic ethylene production and wilting during senescence. The autocatalytic ethylene production is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to the expression of the cysteine proteinase (CPase) gene. So far, it has been believed that the ethylene production and wilting are regulated in concert in senescing carnation petals, since the two events occurred closely in parallel with time. In the present study, we investigated the expression of these genes in petals of a transgenic carnation harboring a sense ACC oxidase transgene and in petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl)semicarbazide (DPSS). In petals of the transgenic carnation flowers, treatment with exogenous ethylene caused accumulation of the transcript for CPase and in-rolling (wilting), whereas it caused no or little accumulation of the transcripts for ACC oxidase and ACC synthase and negligible ethylene production. In petals of the flowers treated with DPSS, the transcripts for ACC synthase and ACC oxidase were accumulated, but no significant change in the level of the transcript for CPase was observed. These results suggest that the expression of ACC synthase and ACC oxidase genes, which leads to ethylene production, is differentially regulated from the expression of CPase, which leads to wilting, in carnation petals.

  15. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L. using high-resolution melting.

    Directory of Open Access Journals (Sweden)

    Tiejun Zhang

    Full Text Available Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L. worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR and single nucleotide polymorphism (SNP markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  16. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L.) using high-resolution melting.

    Science.gov (United States)

    Zhang, Tiejun; Yu, Long-Xi; McCord, Per; Miller, David; Bhamidimarri, Suresh; Johnson, David; Monteros, Maria J; Ho, Julie; Reisen, Peter; Samac, Deborah A

    2014-01-01

    Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L.) worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  17. Is a cysteine proteinase inhibitor involved in the regulation of petal wilting in senescing carnation (Dianthus caryophyllus L.) flowers?

    Science.gov (United States)

    Sugawara, Hiroaki; Shibuya, Kenichi; Yoshioka, Toshihito; Hashiba, Teruyoshi; Satoh, Shigeru

    2002-03-01

    Senescence of carnation petals is accompanied by autocatalytic ethylene production and wilting of the petals; the former is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes and the latter is related to the expression of a cysteine proteinase (CPase) gene. CPase is probably responsible for the degradation of proteins, leading to the decomposition of cell components and resultant cell death during the senescence of petals. The carnation plant also has a gene for the CPase inhibitor (DC-CPIn) that is expressed abundantly in petals at the full opening stage of flowers. In the present study, DC-CPIn cDNA was cloned and expressed in E. coli. The recombinant DC-CPIn protein completely inhibited the activities of a proteinase (CPase) extracted from carnation petals and papain. Northern blot analysis showed that the mRNA for CPase (DC-CP1) accumulated in large amounts, whereas that for DC-CPIn disappeared, corresponding to the onset of petal wilting in flowers undergoing natural senescence and exogenous ethylene-induced senescence. Based on these findings, a role of DC-CPIn in the regulation of petal wilting is suggested; DC-CPIn acts as a suppressor of petal wilting, which probably functions to fine-tune petal wilting in contrast to coarse tuning, the up-regulation of CPase activity by gene expression.

  18. Bacterial gastroenteritis

    Science.gov (United States)

    Bacterial gastroenteritis is present when bacteria cause an infection of the stomach and intestines ... has not been treated Many different types of bacteria can cause ... Campylobacter jejuni E coli Salmonella Shigella Staphylococcus ...

  19. 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.

  20. The effect of wide swathing on wilting times and nutritive value of alfalfa haylage.

    Science.gov (United States)

    Kung, L; Stough, E C; McDonell, E E; Schmidt, R J; Hofherr, M W; Reich, L J; Klingerman, C M

    2010-04-01

    On 3 consecutive cuttings, alfalfa from a single field was mowed with a John Deere 946 mower-conditioner (4-m cut width; Moline, IL) to leave narrow swaths (NS) ranging from 1.2 to 1.52 m wide (30-37% of cutter bar width) and wide swaths (WS) ranging from 2.44 to 2.74 m wide (62-67% of cutter bar width). Samples were collected from windrows and dry matter (DM) was monitored during wilting until a target of 43 to 45% DM was obtained. Forage from random windrows (n=4-6) was harvested by hand, chopped through a forage harvester before being packed in replicated vacuum-sealed bags, and allowed to ensile for 65 d. There was no swath width x cutting interaction for any parameter tested. Over all cuttings, the resulting silage DM was not different between the NS silage (43.8%) and the WS silage (44.9%). However, wide swathing greatly reduced the time of wilting before making silage. The hours of wilting time needed to reach the targeted DM for the NS silage compared with the WS silage at cuttings 1, 2, and 3 were 50 versus 29, 54 versus 28, and 25 versus 6, respectively. At the time of ensiling, the WS silage had more water-soluble carbohydrates (5.1%) than did the NS silage (3.7%). The WS silage had a lower pH (4.58) than did the NS silage (4.66), but swath width did not affect fermentation end products (lactic acid, acetic acid, and ethanol). The NS silage had more NH(3)-N (0.26%) than did the WS silage (0.21%). Wide swathing did not affect the concentration of ash or the digestibility of NDF, but it lowered the N content (NS=3.45%; WS=3.23%) and increased the ADF content (NS=39.7%; WS=40.9%) of the resulting silage. Wide swathing can markedly reduce the time that alfalfa must wilt before it can be chopped for silage, but under good conditions, as in this study, the resulting silage quality was generally not improved.

  1. Isolation, Identification and Activity of an Antagonistic Spore Bacterium against Cotton Verticillium Wilt%一株棉花黄萎病拮抗芽孢细菌的分离鉴定及活性检测

    Institute of Scientific and Technical Information of China (English)

    张冬冬; 李术娜; 郭晓军; 朱宝成

    2012-01-01

    采用改良的琼脂平板扩散法,通过初筛和复筛,得到一株对棉花黄萎病病原菌大丽轮枝菌(Verticillium dahliae)具有较强的抑菌活性的拮抗细菌Z-5菌株.通过对该菌株的形态特征观察、生理生化鉴定和16S rDNA 的序列分析,确定拮抗细菌Z-5菌株为Bacillus malacitensis.盆栽实验表明Z-5菌株对大丽轮枝菌的防治效果达到76.05%,对棉花黄萎病具有明显的防治作用.%A bacterial strain called Z-5 that had strong inhibition capability against Verticillium dahliae V-190 was obtained via preliminary and secondary screening with the improved agar plate diffusion method. Characterized by morphological and cultural features observation, physiological and biochemical experiments, and 16S rDNA sequence analysis, the Z-5 strain was initially identified as Bacillus malacitensis. Control of cotton Verticillium wilt by this antagonistic bacterium was assessed via potted plants. Results showed that the control efficacy of the antagonistic Z-5 strain on cotton Verticillium wilt was 76.05%. Preliminary results demonstrated that the antagonistic Z-5 bacterial strain could significantly inhibit the growth of V. dahliae.

  2. Interactive effects of molasses by homofermentative and heterofermentative inoculants on fermentation quality, nitrogen fractionation, nutritive value and aerobic stability of wilted alfalfa (Medicago sativa L) silage.

    Science.gov (United States)

    Hashemzadeh-Cigari, F; Khorvash, M; Ghorbani, G R; Ghasemi, E; Taghizadeh, A; Kargar, S; Yang, W Z

    2014-04-01

    The effect of adding molasses (0, UM or 50 g/kg on DM basis, M) and two types of inoculant including homofermentative (HO) and a combination of homofermentative and propionate-producing bacterial (HOPAB) inoculants on silage fermentation quality, nitrogen fractionation and aerobic stability of pre-bloom, wilted alfalfa (AS) was determined in laboratory silos. The HOPAB inoculant was more effective than HO in reducing the alfalfa silage pH but increased propionate content in the absence of M (p alfalfa crop with M and HOPAB improved aerobic stability by increasing the concentration of acetate and propionate of AS respectively. Adding M tended (p < 0.10) to increase short-chain fatty acids (SCFA) and cumulative gas production (CGP). HOPAB alone increased DM disappearance at 24 h post-incubation and effective degradability assuming outflow rate of 8%/h relative to untreated AS (p < 0.05). It was concluded that adding M had no pronounced effects on AS fermentation quality, but increased aerobic stability. HOPAB-inoculated AS with no addition of M improved fermentation quality and increased DM degradability compared with HO.

  3. Marker-assisted selection of Fusarium wilt-resistant and gynoecious melon (Cucumis melo L.).

    Science.gov (United States)

    Gao, P; Liu, S; Zhu, Q L; Luan, F S

    2015-12-08

    In this study, molecular markers were designed based on the sex determination genes ACS7 (A) and WIP1 (G) and the domain in the Fusarium oxysporum-resistant gene Fom-2 (F) in order to achieve selection of F. oxysporum-resistant gynoecious melon plants. Markers of A and F are cleaved amplified polymorphic sequences that distinguish alleles according to restriction analysis. Twenty F1 and 1863 F2 plants derived from the crosses between the gynoecious line WI998 and the Fusarium wilt-resistant line MR-1 were genotyped based on the markers. The results showed that the polymerase chain reaction and enzyme digestion results could be effectively used to identify plants with the AAggFF genotype in F2 populations. In the F2 population, 35 gynoecious wilt-resistant plants were selected by marker-assisted selection and were confirmed by disease infection assays, demonstrating that these markers can be used in breeding to select F. oxysporum-resistant gynoecious melon plants.

  4. Effect of silicates and electrical conductivity on Fusarium wilt of hydroponically grown lettuce.

    Science.gov (United States)

    Chitarra, W; Pugliese, M; Gilardi, G; Gullino, M L; Garibaldi, A

    2013-01-01

    Silicon can stimulate natural defense mechanisms in plants, reducing foliar diseases like powdery arid downy mildew on several crops, including lettuce. The effect of silicate on Fusarium wilt, caused by Fusarium oxysporum f. sp. lactucae was evaluated under greenhouse conditions on lettuce grown in soilless systems. Silicon, as potassium silicate, was added at 100 mg L(-1) of nutrient solution at three levels of electrical conductivity; 1.5-1.6 mS cm(-1) (E.C.1), 3.0-3.2 mS cm(-1) (E.C.2) and 4-4.2 mS cm(-1) (E.C.3). Pots containing lettuce plants were first inoculated with F. oxysporum f. sp. lactucae (3x10(5) chlamidospores ml(-1)) 15-20 days before transplanting. Disease severity and physiological parameters, including chlorophyll content, were analyzed weekly after transplanting. The addition of potassium silicate slightly reduced Fusarium wilt, at all levels of electrical conductivity under study, compared to the control. On the contrary, the increase of electrical conductivity of the nutrient solution showed no effect on the disease. The use of silicon was previously demonstrated to significantly reduce downy mildew on lettuce in soilless systems, and in this trial it demonstrated to slightly reduce disease severity of an important soil-borne pathogen like F. oxysporum f. sp. lactucae, suggesting the possibility to apply it successfully in soilless crops.

  5. GENETIC VARIABILITY ASSESSMENT OF FUSARIUM WILT PATHOGEN RACES AFFECTING CHICKPEA USING MOLECULAR MARKERS

    Directory of Open Access Journals (Sweden)

    Jhuma Datta

    2013-06-01

    Full Text Available Genetic diversity in Chickpea wilt pathogen has been characterized using 14 isolates of Fusarium oxysporum f. sp. ciceri (foc collected from major pulse growing regions of India. Out of 247 bands produced by 24 Random Amplified Polymorphic DNA (RAPD primers in Foc isolates, 210 (85% were polymorphic. A maximum of 14 amplicons were generated by primer OPF 05 whereas minimum 7 amplicons were generated by primer K7. A total of 24 alleles were produced by twelve simple sequence repeat (SSR primers with an average of two alleles per marker in foc isolates. The maximum number of 4 alleles was obtained with primer SSR 12. SSR amplicon size ranged from 100 to 400 bp. The Unweighted Pair Group Method with Arithmetic Mean (UPGMA cluster analysis based on RAPD and SSR profiles grouped the fourteen foc isolates into four major clusters. The universal Inter Transcribed Spacer (ITS primer pair amplified 630 bp bands in all fourteen foc isolates while significant length polymorphism was obtained only when analysed by restriction digestion with EcoRI and MspI enzymes. The cluster analysis of ITS-RFLP grouped all 14 Foc isolates into three major clusters. The cluster analysis using RAPD, SSR and ITS-RFLP markers show the grouping of Fusarium isolates strictly according to their cultural characteristics and degree of pathogenicity and not the geographical origin. This information will be helpful for pathologists and plant breeders to design effective resistance breeding programs in chickpea taking into account the diversity in wilt pathogen.

  6. 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.

  7. Mapping and Quantitative Trait Loci Analysis of Verticillium Wilt Resistance Genes in Cotton

    Institute of Scientific and Technical Information of China (English)

    Hong-Mei Wang; Zhong-Xu Lin; Xian-Long Zhang; Wei Chen; Xiao-Ping Guo; Yi-Chun Nie; Yun-Hai Li

    2008-01-01

    Verticillium wilt is one of the most serious constraints to cotton production in almost all of the cotton-growing countries. In this study, "XinLuZao1" (XLZ1), a susceptible cultivar Gossypium hirsutum L. and "Hai7124" (H7124), a resistant line G. barbadense, and their F2:3 families were used to map and study the disease Index induced by verticillium wilt. A total of 430 SSR loci were mapped into 41 linkage groups; the map spanned 3 745.9 cM and the average distance between adjacent loci was 8.71 cM. Four and five quantitative trait loci (QTLs) were detected based on the disease index investigated on July 22 and August 24 in 2004, respectively. These nine QTLs explained 10.63-28.83% of the phenotypic variance, six of them were located on the D sub-genome. Two QTLs located In the same marker intervals may partly explain the significant correlation of the two traits. QTLs explaining large phenotypic variation were identified in this study, which may be quite useful in cotton anti-disease breeding.

  8. 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.

  9. Comparative analysis of the drought-responsive transcriptome in soybean lines contrasting for canopy wilting.

    Science.gov (United States)

    Prince, Silvas J; Joshi, Trupti; Mutava, Raymond N; Syed, Naeem; Joao Vitor, Maldonado Dos Santos; Patil, Gunvant; Song, Li; Wang, JiaoJiao; Lin, Li; Chen, Wei; Shannon, J Grover; Valliyodan, Babu; Xu, Dong; Nguyen, Henry T

    2015-11-01

    Drought stress causes significant yield losses in major oil seed crops, such as soybean [Glycine max (L.) Merr]. Few soybean lines have been identified as canopy-wilting tolerant; however, the molecular mechanism conferring tolerance is not fully understood. To understand the biological process, a whole genome transcriptome analysis was performed for leaf tissues of two contrasting soybean lines: drought-susceptible (DS) Pana and drought-tolerant (DT) PI 567690. A pairwise comparison of the DS and DT lines under drought and control conditions detected 1914 and 670 genes with a greater than two-fold change in expression under drought conditions. Pairwise treatment comparison and gene enrichment analysis on the DT line showed the down-regulation of genes associated with protein binding, hydrolase activity, carbohydrate/lipid metabolism, xyloglucan endo-transglycosylases associated with cell-wall, apoplast, and chlorophyll a/b binding proteins. On the other hand, genes that were associated with the biotic stress response, ion binding and transport, the oxido-reductive process and electron carrier activity were up-regulated. Gene enrichment analysis detected UDP glucuronosyl transferase activity-encoding genes to be differentially expressed in PI 567690 under drought stress conditions. We found valuable SNPs variation in aquaporin genes of the DT line that are conserved in known slower canopy-wilting lines, this should facilitate marker-assisted selection in soybeans with improved drought tolerance.

  10. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    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 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 significantly...

  11. 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

  12. 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...

  13. Bacterial wilt of potato (Ralstonia solanacearum race 3, biovar 2): disease management, pathogen survival and possible eradication

    NARCIS (Netherlands)

    Messiha, N.A.S.

    2006-01-01

    Potato brown rot, caused by Ralstonia solanacearum race 3 biovar 2 (Phylovar II, sequevar 1), is a serious endemic disease in the Nile Delta of Egypt. It is a quarantine disease in the EU, and export of potatoes fromEgypt

  14. Requirements for ER-Arrest and Sequential Exit to the Golgi of Tomato Spotted Wilt Virus Glycoproteins

    NARCIS (Netherlands)

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

    2009-01-01

    The envelope glycoproteins Gn and Gc are major determinants in the assembly of Tomato spotted wilt virus (TSWV) particles at the Golgi complex. In this article, the ER-arrest of singly expressed Gc and the transport of both glycoproteins to the Golgi upon co-expression have been analyzed. While prel

  15. 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, ...

  16. The role of weeds in the spread of Tomato spotted wilt virus by thrips tabaci (Thysanoptera: Thripidae) in tobacco crops

    NARCIS (Netherlands)

    Chatzivassiliou, E.K.; Peters, D.; Katis, N.I.

    2007-01-01

    Oviposition of Thrips tabaci, larval development and their potential to acquire Tomato spotted wilt virus (TSWV) from infected Amaranthus retroflexus, Datura stramonium, Lactuca serriola, Solanum nigrum and Sonchus oleraceus plants and the ability of the adults to transmit this virus to these weeds

  17. Presence and prevalence of Raffaelea lauricola, cause of laurel wilt, in different species of ambrosia beetle in Florida USA

    Science.gov (United States)

    We summarize information on ambrosia beetle species that have been associated in Florida with Raffaelea lauricola, the primary symbiont of Xyleborus glabratus and cause of laurel wilt, a lethal disease of plants in the Lauraceae. Adult females of 14 species in Ambrosiodmus, Euwallacea, Premnobius, ...

  18. 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...

  19. 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.

  20. [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.

  1. 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.

  2. Biochemical Defenses Induced by Mycorrhizae Fungi Glomus Mosseae in Controlling Strawberry Fusarium Wilt.

    Science.gov (United States)

    Yanan, Wang; Xusheng, Zhao; Baozhong, Yin; Wenchao, Zhen; Jintang, Guo

    2015-01-01

    The effect of VAM on reducing wilt caused by Fusarium oxysporum Schlecht. f.sp. fragariae Winks et Williams (FO) infection in strawberry and the possible mechanisms involved were investigated. Two key substance involved in disease defenses, lignin and hydroxyproline-rich glycoprotein were induced and formed in the cell wall of strawberry root, and the peak content of lignin and hydroxyproline-rich glycoprotein occurred on the 25(th) day (149.52mg/g) and on the 15(th) day (10.08 mg/g). The activity of protective enzymes SOD, POD and CAT inoculation with VAM significantly increased when compared with the control under both CK (natural growth) and inoculated with FO. The conductivity of VAM plus FO treatment was higher than the CK treatment, but significantly was lower than the FO treatment.

  3. Evolutionary analysis of tomato Sw-5 resistance-breaking isolates of Tomato spotted wilt virus.

    Science.gov (United States)

    López, Carmelo; Aramburu, José; Galipienso, Luis; Soler, Salvador; Nuez, Fernando; Rubio, Luis

    2011-01-01

    Tomato spotted wilt virus (TSWV) causes severe economic losses in many crops worldwide and often overcomes resistant cultivars used for disease control. Comparison of nucleotide and amino acid sequences suggested that tomato resistance conferred by the gene Sw-5 can be overcome by the amino acid substitution C to Y at position 118 (C118Y) or T120N in the TSWV movement protein, NSm. Phylogenetic analysis revealed that substitution C118Y has occurred independently three times in the studied isolates by convergent evolution, whereas the substitution T120N was a unique event. Analysis of rates of non-synonymous and synonymous changes at individual codons showed that substitution C118Y was positively selected.

  4. 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.

  5. Potency of six isolates of biocontrol agents endophytic Trichoderma against fusarium wilt on banana

    Directory of Open Access Journals (Sweden)

    J Taribuka

    2017-01-01

    Full Text Available Fusarium wilt caused by F. oxysporum f.sp. cubense is one of very damaging banana plant diseases which can cause plant death. Disease control using intensive chemical fungicides will have negative impacts on the environment and humans. Endophytic Trichoderma is one of the biological control agents which can reduce the amount of inoculum of pathogens, so it can reduce disease intensity. The objectives of this study was to assess the ability of endophytic Trichoderma in inducing plant resistance against fusarium wilt. Endophytic Trichoderma was obtained from healthy roots of banana from three regencies in Yogyakarta, namely Trichoderma harzianum.swn-1, T. harzianum.swn-2, T. harzianum.psr-1, T. asperrellum, T. gamsii, and T. koningiopsis. Research on induced resintance was conducted in the greenhouse with polybag using Completely Randomized Design with 14 treatments and 3 replications. The results showed that the ability of Trichoderma gamsii antagonism against F. oxysporum f.sp. cubense was 60.61%. T. asperellum and T. harzianum.swn-2 could suppress this disease resulted in disease intensity of 8.33% which categorize as resistant. Trichoderma harzianum.psr-1 was significantly different in stimulating plant vegetative growth. Induced resistance by using endophytic Trichoderma spp. against  F. oxysporum f.sp. cubense showed increase in total phenolic compounds on the third and fourth weeks as well as peroxidase activity on the third, fourth and fifth weeks.  Observation of lignification on  the fifth week  showed that lignification occurred in root xylem

  6. 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.

  7. Insights into the Regulation of Rhizosphere Bacterial Communities by Application of Bio-organic Fertilizer in Pseudostellaria heterophylla Monoculture Regime

    Directory of Open Access Journals (Sweden)

    Linkun Wu

    2016-11-01

    Full Text Available The biomass and quality of Pseudostellariae heterophylla suffers a significant decline under monoculture. Since rhizosphere microbiome plays crucial roles in soil health, deep pyrosequencing combined with qPCR was applied to characterize the composition and structure of soil bacterial community under monoculture and different amendments. The results showed compared with the first-year planted (FP, second-year monoculture of P. heterophylla (SP led to a significant decline in yield and resulted in a significant increase in Fusarium oxysporum but a decline in Burkholderia spp. Bio-organic fertilizer (MT formulated by combining antagonistic bacteria with organic matter could significantly promote the yield by regulating rhizosphere bacterial community. However, organic fertilizer (MO without antagonistic bacteria could not suppress Fusarium wilt. Multivariate statistics analysis showed a distinct separation between the healthy samples (FP and MT and the unhealthy samples (SP and MO, suggesting a strong relationship between soil microbial community and plant performance. Furthermore, we found the application of bio-organic fertilizer MT could significantly increase the bacterial community diversity and restructure microbial community with relatively fewer pathogenic F. oxysporum and more beneficial Burkholderia spp. In conclusion, the application of novel bio-organic fertilizer could effectively suppress Fusarium wilt by enriching the antagonistic bacteria and enhancing the bacterial diversity.

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

    OpenAIRE

    Subbarao, Krishna V.

    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...

  10. 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.

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

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    H. Zarzycka

    2015-06-01

    Full Text Available 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 after rape, hemp, potato and leguminous plants. The crop rotation significantly influenced the composition of the Fusarium population as far as species are concerned. The highest wilt infection of flax was found in plantings after flax, sugarbeet and wheat and the weakest in plantings after rape. A six-year crop rotation was sufficient to eliminate the wilt pathogen from infested soil. But on flax-sick soil the process of biological disinfestation proceeded more slowly and a seven-year interval between flax crops was too short.

  12. Suppression of Fusarium wilt of cucumber by ammonia gas fumigation via reduction of Fusarium population in the field

    Science.gov (United States)

    Zhao, Jun; Mei, Zhong; Zhang, Xu; Xue, Chao; Zhang, Chenzhi; Ma, Tengfei; Zhang, Shusheng

    2017-01-01

    Cucumber plants subjected to consecutive monoculture for 9 years were found to suffer from severe Fusarium wilt disease, caused by the soil-borne fungus Fusarium oxysporum f. sp. Cucumerinum J. H. Owen. In the present study, greenhouse experiments were performed to evaluate the influence of ammonia gas fumigation on Fusarium wilt suppression, fungal abundance and fungal community composition. Results showed that ammonia gas fumigation remarkably reduced disease incidence from 80% to 27%, resulting in a four-fold increase in yield, compared to the control. Total fungal abundance declined dramatically after fumigation and reached the lowest level at day 32, at 243 times lower than the control. Moreover, fumigation significantly increased soil fungal diversity, though it also decreased considerably coinciding with cucumber growth. Fumigation also significantly altered soil fungal community composition, relative to the control. Fusarium was strongly inhibited by fumigation in both relative abundance (3.8 times lower) and targeted quantification (a decrease of 167 fold). Collectively, the application of ammonia gas fumigation to control Fusarium wilt of cucumber resulted in a re-assembly of the fungal community to resemble that of a non-disease conducive consortium. Additional strategies, such as bioorganic fertilizer application, may still be required to develop sustainable disease suppression following fumigation. PMID:28230182

  13. 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.

  14. Genetic structure, linkage disequilibrium and association mapping of Verticillium wilt resistance in elite cotton (Gossypium hirsutum L.) germplasm population.

    Science.gov (United States)

    Zhao, Yunlei; Wang, Hongmei; Chen, Wei; Li, Yunhai

    2014-01-01

    Understanding the population structure and linkage disequilibrium in an association panel can effectively avoid spurious associations and improve the accuracy in association mapping. In this study, one hundred and fifty eight elite cotton (Gossypium hirsutum L.) germplasm from all over the world, which were genotyped with 212 whole genome-wide marker loci and phenotyped with an disease nursery and greenhouse screening method, were assayed for population structure, linkage disequilibrium, and association mapping of Verticillium wilt resistance. A total of 480 alleles ranging from 2 to 4 per locus were identified from all collections. Model-based analysis identified two groups (G1 and G2) and seven subgroups (G1a-c, G2a-d), and differentiation analysis showed that subgroup having a single origin or pedigree was apt to differentiate with those having a mixed origin. Only 8.12% linked marker pairs showed significant LD (Pmapping, which widely were distributed among 15 chromosomes. Among which 10 marker loci were found to be consistent with previously identified QTLs and 32 were new unreported marker loci, and QTL clusters for Verticillium wilt resistanc on Chr.16 were also proved in our study, which was consistent with the strong linkage in this chromosome. Our results would contribute to association mapping and supply the marker candidates for marker-assisted selection of Verticillium wilt resistance in cotton.

  15. Bacterial vaginosis -- aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000687.htm Bacterial vaginosis - aftercare To use the sharing features on this ... to back after you use the bathroom. Preventing Bacterial Vaginosis You can help prevent bacterial vaginosis by: Not ...

  16. Pregnancy Complications: Bacterial Vaginosis

    Science.gov (United States)

    ... Complications & Loss > Pregnancy complications > Bacterial vaginosis and pregnancy Bacterial vaginosis and pregnancy E-mail to a friend Please ... this page It's been added to your dashboard . Bacterial vaginosis (also called BV or vaginitis) is an infection ...

  17. Conservation characteristics of wilted perennial ryegrass silage made using biological or chemical additives.

    Science.gov (United States)

    Conaghan, P; O'Kiely, P; O'Mara, F P

    2010-02-01

    The effects of 7 additive treatments on the fermentation and aerobic stability characteristics of wilted grass silage were studied under laboratory conditions. Treatments included no additive applied (untreated control), ammonium tetraformate at 3 and 6 L/t, homofermentative lactic acid bacteria alone ((ho)LAB), a mixture of Lactobacillus buchneri plus homofermentative lactic acid bacteria ((he+ho)LAB), and an antimicrobial mixture of sodium benzoate, sodium propionate, sodium nitrite, and hexamethylenetetramine at 2.5 and 5 L/t. Additives were compared across 3 consecutive harvests of 2 perennial ryegrass cultivars (AberDart and Fennema) following a 24-h wilt. Silos were opened after at least 100 d of ensilage and aerobic stability was assessed. Season of harvest had a large effect on grass composition at ensiling, producing herbages of relatively low (approximately 145g/kg), medium (approximately 250g/kg), and high (approximately 365g/kg) dry matter (DM) concentrations. Within harvests there were lesser differences between cultivars. The untreated control and (ho)LAB additive produced badly fermented silage from the low-DM herbages and well-fermented silage from the medium- and high-DM herbages. The ammonium tetraformate treatments produced both well-fermented and badly fermented silage from the low-DM herbages depending on cultivar, and consistently well-fermented silage from the medium- and high-DM herbages. The (he+ho)LAB silages had similar or slightly lower standard of fermentation than the untreated and (ho)LAB silages. The antimicrobial mixture produced more silages of lower standard of fermentation than the untreated control and ammonium tetraformate and (ho)LAB additives. All additive treatments, including the untreated control, failed to consistently increase residual water-soluble carbohydrate concentrations at silo opening. Ammonium tetraformate at 6 L/t was the most successful and (he+ho)LAB the least successful additive at increasing residual WSC

  18. 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

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

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    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

  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. Seedling regeneration on decayed pine logs after the deforestation events caused by pine wilt disease

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    Y. Fukasawa

    2016-12-01

    Full Text Available Coarse woody debris (CWD forms an important habitat suitable for tree seedling establishment, and the CWD decay process influences tree seedling community. In Japan, a severe dieback of Pinus densiflora Sieb. & Zucc. caused by pine wilt disease (PWD damaged huge areas of pine stands but creates huge mass of pine CWD. It is important to know the factors influencing seedling colonization on pine CWD and their variations among geographical gradient in Japan to expect forest regeneration in post-PWD stands. I conducted field surveys on the effects of latitude, climates, light condition, decay type of pine logs, and log diameter on tree seedling colonization at ten geographically distinct sites in Japan. In total, 59 tree taxa were recorded as seedlings on pine logs. Among them, 13 species were recorded from more than five sites as adult trees or seedlings and were used for the analyses. A generalized linear model showed that seedling colonization of Pinus densiflora was negatively associated with brown rot in sapwood, while that of Rhus trichocarpa was positively associated with brown rot in heartwood. Regeneration of Ilex macropoda had no relationships with wood decay type but negatively associated with latitude and MAT, while positively with log diameter. These results suggested that wood decay type is a strong determinant of seedling establishment for certain tree species, even at a wide geographical scale; however, the effect is tree species specific.

  2. Development and preventative effect against pine wilt disease of a novel liquid formulation of emamectin benzoate.

    Science.gov (United States)

    Takai, Kazuya; Suzuki, Toshio; Kawazu, Kazuyoshi

    2003-03-01

    Injection of the poorly water-soluble emamectin benzoate (EB) into pine trunks required the development of an efficient liquid formulation. For injection into big trees in forests a good rate of injection and a high active content were required. Tests on the viscosity and EB-solubilizing ability of 14 various solubilizers in diethylene glycol monobutyl ether (DGMBE) led to the selection of Sorpol SM-100PM as the solubilizer of the formulation. Relationships between the solubilizing ability and amounts of Sorpol SM-100PM and DGMBE relative to that of EB, and between the concentration of the latter and the viscosity or the injection rate of the formulation led to a novel 40 g litre(-1) emamectin benzoate formulation (Shot Wan Liquid Formulation), which was composed of EB (40), Sorpol SM-100PM (120), DGMBE (160) and distilled water (50 g litre(-1)) in methanol. Injection of this formulation at a dose of 10 g EB per unit volume of pine tree prevented over 90% of the trees from wilting caused by pine wood nematode, and this preventative effect continued for 3 years. Neither discolouration of the leaves nor injury around the injection hole on the trees was observed after injection of the formulation.

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

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    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.

  4. 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

  5. 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.

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

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    Jerome ePouzoulet

    2014-06-01

    Full Text Available 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 colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance towards vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management.

  7. 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

  8. 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.

  9. Genome and transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. cubense causing banana vascular wilt disease.

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    Lijia Guo

    Full Text Available BACKGROUND: The asexual fungus Fusarium oxysporum f. sp. cubense (Foc causing vascular wilt disease is one of the most devastating pathogens of banana (Musa spp.. To understand the molecular underpinning of pathogenicity in Foc, the genomes and transcriptomes of two Foc isolates were sequenced. METHODOLOGY/PRINCIPAL FINDINGS: Genome analysis revealed that the genome structures of race 1 and race 4 isolates were highly syntenic with those of F. oxysporum f. sp. lycopersici strain Fol4287. A large number of putative virulence associated genes were identified in both Foc genomes, including genes putatively involved in root attachment, cell degradation, detoxification of toxin, transport, secondary metabolites biosynthesis and signal transductions. Importantly, relative to the Foc race 1 isolate (Foc1, the Foc race 4 isolate (Foc4 has evolved with some expanded gene families of transporters and transcription factors for transport of toxins and nutrients that may facilitate its ability to adapt to host environments and contribute to pathogenicity to banana. Transcriptome analysis disclosed a significant difference in transcriptional responses between Foc1 and Foc4 at 48 h post inoculation to the banana 'Brazil' in comparison with the vegetative growth stage. Of particular note, more virulence-associated genes were up regulated in Foc4 than in Foc1. Several signaling pathways like the mitogen-activated protein kinase Fmk1 mediated invasion growth pathway, the FGA1-mediated G protein signaling pathway and a pathogenicity associated two-component system were activated in Foc4 rather than in Foc1. Together, these differences in gene content and transcription response between Foc1 and Foc4 might account for variation in their virulence during infection of the banana variety 'Brazil'. CONCLUSIONS/SIGNIFICANCE: Foc genome sequences will facilitate us to identify pathogenicity mechanism involved in the banana vascular wilt disease development. These will

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

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    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.

  11. Stable integration and expression of a plant defensin in tomato confers resistance to fusarium wilt.

    Science.gov (United States)

    Abdallah, Naglaa A; Shah, Dilip; Abbas, Dina; Madkour, Magdy

    2010-01-01

    Plant defensins are small cysteine-rich peptides which belong to a group of pathogenasis related defense mechanism proteins. The proteins inhibit the growth of a broad range of microbes and are highly stable under extreme environmental stresses. Tomato cultivation is affected by fungal disease such as Fusarium wilt. In order to overcome fungal damages, transgenic tomato plants expressing the Medicago sativa defensin gene MsDef1 under the control of the CaMV 35S promoter were developed. The Fusarium-susceptible tomato (Lycobersicum esculentum Mill) cultivar CastleRock was used for transformation to acquire fungal resistance. Hypocotyl with a part of cotyledon (hypocotyledonary) for young tomato seedlings were used as an explant material and transformation was performed using the biolistic delivery system. Bombarded shoots were selected on regeneration medium supplemented with hygromycin and suitable concentrations of BA, zeatin ripozide and AgNO(3). Putative transgenic plantlets of T(0) were confirmed by PCR analysis using primers specific for the transgene and the transformation frequency obtained was 52.3%. Transformation and transcription of transgenes were confirmed in T(1) by PCR, Southern hybridizations, and reverse-transcription PCR (RT-PCR). The copy numbers of integrated transgene into tomato genome ranged between 1-3 copies. Greenhouse bioassay was performed on the transgenic T(1) and T(2) young seedlings and non-transgenic controls by challenging with a vigorous isolate of the fungal pathogen Fusarium oxysporum f. sp. Lycopersici. The level of fungal infectivity was determined using RT-PCR with tomatinase specific primers. Transgenic lines were more resistant to infection by fusarium than the control plants. These results indicated that overexpressing defensins in transgenic plants confer resistance to fungal pathogens.

  12. 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.

  13. 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

  14. 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.

  15. Quantification of propagules of the laurel wilt fungus and other mycangial fungi from the redbay ambrosia beetle, Xyleborus glabratus.

    Science.gov (United States)

    Harrington, T C; Fraedrich, S W

    2010-10-01

    The laurel wilt pathogen, Raffaelea lauricola, is a fungal symbiont of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia and was believed to have brought R. lauricola with it to the southeastern United States. Individual X. glabratus beetles from six populations in South Carolina and Georgia were individually macerated in glass tissue grinders and serially diluted to quantify the CFU of fungal symbionts. Six species of Raffaelea were isolated, with up to four species from an individual adult beetle. The Raffaelea spp. were apparently within the protected, paired, mandibular mycangia because they were as numerous in heads as in whole beetles, and surface-sterilized heads or whole bodies yielded as many or more CFU as did nonsterilized heads or whole beetles. R. lauricola was isolated from 40 of the 41 beetles sampled, and it was isolated in the highest numbers, up to 30,000 CFU/beetle. Depending on the population sampled, R. subalba or R. ellipticospora was the next most frequently isolated species. R. arxii, R. fusca, and R. subfusca were only occasionally isolated. The laurel wilt pathogen apparently grows in a yeast phase within the mycangia in competition with other Raffaelea spp.

  16. Intragenome distribution of 5-methylcytosine in DNA of healthy and wilt-infected cotton plants (Gossypium hirsutum L.).

    Science.gov (United States)

    Guseinov, V A; Kiryanov, G I; Vanyushin, B F

    1975-03-01

    Fractionation of DNA of healthy and wilt-infected cotton plants has been carried out according to the reassociation kinetics and the content of GC and 5-methylcytosine in the resulting fractions has been studied. The genome of cotton plant was found to be methylated quite unevenly. The GC rich (GC equals 64.7 mole%) fraction of highly reiterated sequences (Cot equals 0-3.7 times 10- minus 2) has a high content of 5-methylcytosine (5.8 mole%), whereas the methylation degree of the fraction of unique sequences (Cot larger than or equal to 487) is very low (the 5-methylcytosine content is about 0.5 mole%). In plants being infected with wilt, the 5-methylcytosine content in DNA or cotton leaves decreases two-fold; no changes in the structure and molecular population of DNA has been found. The sharp change in the 5-methylcytosine content in DNA of infected plants takes place at the expense of the decrease in the 5-methylcytosine content in fractions of highly reiterated sequences. The methylation degree of unique sequences (structural genes) remains unchanged.

  17. 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.

  18. 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.

  19. Comparison of Fungal Community in Black Pepper-Vanilla and Vanilla Monoculture Systems Associated with Vanilla Fusarium Wilt Disease.

    Science.gov (United States)

    Xiong, Wu; Zhao, Qingyun; Xue, Chao; Xun, Weibing; Zhao, Jun; Wu, Huasong; Li, Rong; Shen, Qirong

    2016-01-01

    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 harbored a lower abundance of Fusarium 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.

  20. Screening and Functional Analysis of the Peroxiredoxin Specifically Expressed in Bursaphelenchus xylophilus—The Causative Agent of Pine Wilt Disease

    Directory of Open Access Journals (Sweden)

    Han-Yu Fu

    2014-06-01

    Full Text Available The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. Accurately differentiating B. xylophilus from other nematodes species, especially its related species B. mucronatus, is important for pine wood nematode detection. Thus, we attempted to identify a specific protein in the pine wood nematode using proteomics technology. Here, we compared the proteomes of B. xylophilus and B. mucronatus using Two-dimensional gel electrophoresis (2-DE and matrix-assisted laser desorption/ionization -time-of-flight/time-of-flight (MALDI-TOF/TOF-MS technologies. In total, 15 highly expressed proteins were identified in B. xylophilus compared with B. mucronatus. Subsequently, the specificity of the proteins identified was confirmed by PCR using the genomic DNA of other nematode species. Finally, a gene encoding a specific protein (Bx-Prx was obtained. This gene was cloned and expressed in E. coli. The in situ hybridisation pattern of Bx-Prx showed that it was expressed strongly in the tail of B. xylophilus. RNAi was used to assess the function of Bx-Prx, the results indicated that the gene was associated with the reproduction and pathogenicity of B. xylophilus. This discovery provides fundamental information for identifying B. xylophilus via a molecular approach. Moreover, the purified recombinant protein has potential as a candidate diagnostic antigen of pine wilt disease, which may lead to a new immunological detection method for the pine wood nematode.

  1. The effect of formaldehyde treatment before ensiling on the digestion of wilted grass silage by sheep.

    Science.gov (United States)

    Siddons, R C; Evans, R T; Beever, D E

    1979-11-01

    1. Wilted perennial ryegrass (Lolium perenne L. cv. Endura) was ensiled without additive or after addition of a mixture of equal volumes of formic acid (850 g/kg) and formalin (380 g formaldehyde/kg) applied at a rate of 35 g formaldehyde/kg herbage crude protein (nitrogen x 6.25). The digestion of the two silages and the effect of supplemental N as urea or urea plus soya-bean meal on the digestion of the treated silage was studied using sheep fitted with a rumen cannula and re-entrant cannulas in the proximal duodenum and distal ileum. 2. The additive markedly reduced carbohydrate fermentation and protein degradation in the silo. 3. There were no significant differences between diets in rumen pH, dilution rate, volatile fatty acid production and the molar proportions of acetate, propionate and butyrate. However, rumen ammonia levels and the apparent digestibility of organic matter (OM), gross energy (GE) and cellulose in the stomach were significantly depressed (P less than 0.05) by the additive. It also reduced (P less than 0.05) the extent to which the N of the silage was degraded in the rumen and, with the treated silage, more microbial N was synthesized in the rumen than food N degraded, resulting in a net grain of N between mouth and duodenum, as compared to a net loss with the untreated silage. 4. Supplementation of the treated silage with urea or urea plus soya-bean meal significantly increased (P less than 0.05) the amount of food N degraded in the rumen and rumen ammonia levels but had no effect on the apparent digestibility of OM, GE and cellulose in the stomach or on the amount of microbial N reaching the duodenum. 5. The quantity of microbial amino acids entering the small intestine and the apparent digestibility of amino acids in the small intestine were similar for all four diets. However, the quantity of food amino acids reaching the small intestine was significantly higher with the three diets containing the treated silage and consequently the

  2. Sintomatologia da murcha de Ceratocystis fimbriata em eucalipto Symptomatology of Ceratocystis wilt in eucalyptus

    Directory of Open Access Journals (Sweden)

    Francisco Alves Ferreira

    2006-04-01

    Full Text Available Descreveram-se o histórico da murcha de Ceratocystis fimbriata em eucalipto no Brasil e em outros países e a sintomatologia da doença, em plantações clonais com 4 meses a 5 anos de idade, em brotações de tocos, em estacas em enraizamento e em mudas clonais em viveiro, de quatro estados brasileiros. O patógeno evoluía-se da extremidade da raiz, atingindo o colo e tronco acima via parênquima medular, de onde, em diversas alturas, surgiam estrias escuras, que progrediam, via parênquima radial, matando uma porção de câmbio vascular, de floema e de feloderme. Dessa progressão sistêmica do patógeno, ascendente e radialmente, resultava uma lesão longitudinal externamente no tronco, contínua ou descontínua, marrom-avermelhada, coriácea, que passava a sulcada e, posteriormente, a cancro longitudinal, com seus calos longilíneos nas duas laterais. Por esse contexto sintomatológico, pode-se considerar essa enfermidade como um modelo de doença sistêmica em essência florestal, pelo menos na subárea da patologia florestal brasileira. Em brotações novas, em estacas em enraizamento e em mudas clonais as lesões eram longitudinais, contínuas ou descontínuas, negras a arroxeadas. A inativação de xilema em raízes, colo e em diferentes alturas do tronco, ou galho, dava-se pelo adensamento das estrias radiais escuras no lenho.The symptomatology of Ceratocystis fimbriata wilt in eucalyptus was described based on observations of 4-month to 5-year-old clonal plantations, in stump sprouts, rooting cuttings, and rooted seedlings in nurseries. The disease was characterized as a model of systemic disease in woody plants, which starts in roots and progresses upward to the collar and trunk through the medullar parenchyma, where dark stripes irradiate and lead a portion of the vascular cambium, phloem and phelloderm to death. As the pathogen spread upward and radially, a longitudinal reddish-brown, continuous or non-continuous corky lesion

  3. 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.; 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

  4. Entomopathogenic fungi as a biological control agents for the vector of the laurel wilt disease, the redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae)

    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...

  5. 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...

  6. Genotyping-by-sequencing based genome-wide association studies on Verticillium wilt resistance in heterozygous autotetraploid alfalfa (Medicago sativa L.)

    Science.gov (United States)

    Verticillium wilt (VW) is a fungal disease which causes severe yield loss in alfalfa. The most effective method to control the disease is through the development and use of resistant varieties. Identification of gene loci linked to VW resistance will facilitate breeding for the disease-resistant al...

  7. Identification of defense-related genes associated with tomato Sw-7 line against Tomato spotted wilt virus in tomato through transcriptome analysis

    Science.gov (United States)

    Tomato spotted wilt virus (TSWV) is a highly infectious tospovirus, and one of the most damaging plant viruses infecting tomatoes worldwide. Developing a tomato cultivar with TSWV-resistance would be the most effective approach for disease management. Comparative analysis of differential expression ...

  8. Selection for resistance to Verticillium wilt caused by race 2 isolates of Verticillium dahliae in accessions of lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Verticillium wilt of lettuce caused by Verticillium dahliae can cause severe economic damage to lettuce producers. The pathogen exists as two races (races 1 and 2) in lettuce, and complete resistance to race 1 is known. Resistance to race 2 isolates has not been reported, and production of race 1 re...

  9. Application of phage display in selecting Tomato spotted wilt virus - specific single-chain antibodies (scFvs) for sensitive diagnosis in ELISA

    NARCIS (Netherlands)

    Griep, R.A.; Prins, M.; Twisk, van C.; Keller, H.J.H.G.; Kerschbaumer, R.J.; Kormelink, R.; Goldbach, R.W.; Schots, A.

    2000-01-01

    A panel of recombinant single-chain antibodies (scFvs) against structural proteins of Tomato spotted wilt virus (TSWV) was retrieved from a human combinatorial scFv antibody library using the novel phage display technique. After subcloning the encoding DNA sequences in the expression vector pSKAP/S,

  10. First report of a resistance-breaking strain of Tomato spotted wilt virus infecting tomatoes with the Sw-5 tospovirus-resistance gene in California

    Science.gov (United States)

    Management of Tomato spotted wilt virus (TSWV) with the Sw-5 resistance gene in tomato is highly effective. However, in certain regions of the world where resistant tomatoes have been continually planted, resistance-breaking strains of TSWV have emerged. In spring 2016 resistant tomatoes were obse...

  11. 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...

  12. 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

    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 content in the red clover silages (50·1 vs. 34·2 mg kg−1 DM; P = 0·015) compared with untreated red clover silages. Red clover mixtures had lower β-carotene content than Bft + Ti (32·3 vs. 46·2 mg kg−1 DM; P = 0·016), averaged over treatments. In conclusion, wilting had small effects but the use...

  13. Biological control of strawberry Fusarium wilt caused by Fusarium oxysporum f. sp. fragariae using Bacillus velezensis BS87 and RK1 formulation.

    Science.gov (United States)

    Nam, Myeong Hyeon; Park, Myung Soo; Kim, Hong Gi; Yoo, Sung Joon

    2009-05-01

    Two isolates, Bacillus sp. BS87 and RK1, selected from soil in strawberry fields in Korea, showed high levels of antagonism towards Fusarium oxysporum f. sp. fragariae in vitro. The isolates were identified as B. velezensis based on the homology of their gyrA sequences to reference strains. BS87 and RK1 were evaluated for control of Fusarium wilt in strawberries in pot trials and field trials conducted in Nonsan, Korea. In the pot trials, the optimum applied concentration of BS87 and RK1 for pre-plant root-dip application to control Fusarium wilt was 10(5) and 10(6) colony-forming units (CFU)/ml, respectively. Meanwhile, in the 2003 and 2005 field trials, the biological control efficacies of formulations of RK1 were similar to that of a conventional fungicide (copper hydroxide) when compared with a non-treated control. The RK1 formulation was also more effective than BS87 in suppressing Fusarium wilt under field conditions. Therefore, the results indicated that formulation of B.velezensis BS87 and RK1 may have potential to control Fusarium wilt in strawberries.

  14. 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 imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... 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 become...

  15. Molecular mapping of Verticillium wilt resistance QTL clustered on chromosomes D7 and D9 in upland cotton

    Institute of Scientific and Technical Information of China (English)

    JIANG Feng; ZHAO Jun; ZHOU Lei; GUO WangZhen; ZHANG TianZhen

    2009-01-01

    Verticillium wilt is s destructive disease with international consequences for cotton production. Breeding broad-spectrum resistant cultivars is considered to be one of the most effective means for reducing crop losses. A resistant cotton cultivar, 60182, was crossed with a susceptible cultivar, Junmian 1, to identify markers for Verticillium resistance genes and validate the mode of its inheritance. Genetic segregation analysis for Verticillium wilt resistance was evaluated based upon infected leaf percentage in the seedling stage using major gene-polygene mixed inheritance models and joint analysis of P_1, P_2, F_1, B_1, B_2 and F_2 populations obtained from the cultivar cross. We found that resistance of upland cotton cultivar 60182 to isolates BP2, VD8 and T9, and their isoconcentration mixture was controlled by two major genes with additive-dominance-epistatic effects, and the inheritance of the major gene was dominant. Furthermore, a genetic linkage map was constructed using F_2 segregating population and resistance phenotypic data were obtained using F_(2:3) families inoculated with different isolates and detected in different developmental stages. The genetic linkage map with 139 loci was comprised of 31 linkage groups covering 1165 cM, with an average distance of 8.38 cM between two markers, or 25.89% of the cotton genome length. From 60182, we found 4 QTL on chromosome D7 and 4 QTL on D9 for BP2, 5 QTL on D7 and 9 QTL on D9 for VD8, 4 QTL on D7 and 5 QTL on D9 for T9 and 3 QTL on D7 and 7 QTL on D7 for mixed pathogens. The QTL mapping results revealed that QTL clusters with high contribution rates were screened simultaneously on chromosomes D9 and D7 by multiple interval mapping (CIM), whether from resistance phenotypic data from different developmental stages or for different isolates. The result is consistent with the genetic model of two major genes in 60182 and suggests broad-spectrum resistance to both defoliating isolates of V. dahliae and

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

    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.

  17. Fusarium Wilt of Banana Is Caused by Several Pathogens Referred to as Fusarium oxysporum f. sp. cubense.

    Science.gov (United States)

    Ploetz, Randy C

    2006-06-01

    ABSTRACT Fusarium wilt of banana (also known as Panama disease) is caused by Fusarium oxysporum f. sp. cubense. Where susceptible cultivars are grown, management is limited to the use of pathogen-free planting stock and clean soils. Resistant genotypes exist for some applications, but resistance is still needed in other situations. Progress has been made with this recalcitrant crop by traditional and nontraditional improvement programs. The disease was first reported in Australia in 1876, but did the greatest damage in export plantations in the western tropics before 1960. A new variant, tropical race 4, threatens the trades that are now based on Cavendish cultivars, and other locally important types such as the plantains. Phylogenetic studies indicate that F. oxysporum f. sp. cubense had several independent evolutionary origins. The significance of these results and the future impact of this disease are discussed.

  18. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  19. 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.

  20. 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 ...... valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  1. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    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...

  2. The fatty acid composition of muscle and adipose tissue of steers offered unwilted or wilted grass silage supplemented with sunflower oil and fishoil.

    Science.gov (United States)

    Noci, F; Monahan, F J; Scollan, N D; Moloney, A P

    2007-03-01

    The effects of the type of grass silage and dietary inclusion of fish oil (FO) on the fatty acid profile of bovine intramuscular and subcutaneous adipose tissue were investigated. Eighty Friesian steers were assigned (n 10) to unwilted or wilted silage, and to one of four rations which contained, per kg, 80 g of sunflower oil and either 0, 10, 20 or 40 g of FO replacing lard. Animals were slaughtered after 108 d and the fatty acid profile of the neutral, polar and total lipid fractions of the M. longissimus dorsi, and the total lipid fraction of the subcutaneous adipose tissue were determined. Wilting of grass prior to ensiling increased the concentration of conjugated linoleic acid (CLA) in intramuscular total lipid (P<0 x 01), but did not affect the n-6:n-3 PUFA ratio. Increasing FO supply linearly increased (P<0 x 05) the concentration of the cis-9, trans-11 and trans-10, cis-12 isomers of CLA and trans-11 18 : 1 predominantly in the neutral lipid fraction of intramuscular total lipid, and linearly decreased the n-6:n-3 PUFA ratio. Wilting of grass prior to ensiling increased the concentration of CLA in subcutaneous adipose tissue (P<0 x 001), while increasing FO supply linearly increased the concentration of cis-9, trans-11 CLA. From a human nutrition perspective, increasing the level of FO in the ration or wilting of grass prior to ensiling appear to modify the fatty acid composition of beef muscle favourably. However, the health implications of associated increases in trans fatty acids remain to be elucidated.

  3. The Tomato spotted wilt virus genome is processed differentially in its plant host Arachis hypogaea and its thrips vector Frankliniella fusca

    OpenAIRE

    Stephen John Fletcher; Anita Shrestha; Jonathan Peters; Carroll, Bernard J.; Rajagopalbabu Srinivasan; Pappu, Hanu R.; Neena Mitter

    2016-01-01

    Thrips-transmitted tospoviruses are economically important viruses affecting a wide range of field and horticultural crops worldwide. Tomato spotted wilt virus is the type member of the Tospovirus genus with a broad host range of more than 900 plant species. Interactions between these viruses and their plant hosts and insect vectors via RNA interference pathways are likely a key determinant of pathogenicity. The current investigation, for the first time, compares biogenesis of small RNAs be...

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

    OpenAIRE

    Jerome ePouzoulet; Alexandria ePivovaroff; Louis eSantiago; Philippe Eric Rolshausen

    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 ...

  5. Expression of baculovirus anti-apoptotic genes p35 and op-iap in cotton (Gossypium hirsutum L. enhances tolerance to verticillium wilt.

    Directory of Open Access Journals (Sweden)

    Juan Tian

    Full Text Available BACKGROUND: Programmed cell death plays an important role in mediating plant adaptive responses to the environment such as the invasion of pathogens. Verticillium wilt, caused by the necrotrophic pathogen Verticillium dahliae, is a serious vascular disease responsible for great economic losses to cotton, but the molecular mechanisms of verticillium disease and effective, safe methods of resistance to verticillium wilt remain unexplored. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we introduced baculovirus apoptosis inhibitor genes p35 and op-iap into the genome of cotton via Agrobacterium-mediated transformation and analyzed the response of transgenic plants to verticillium wilt. Results showed that p35 and op-iap constructs were stably integrated into the cotton genome, expressed in the transgenic lines, and inherited through the T(3 generation. The transgenic lines had significantly increased tolerance to verticillium wilt throughout the developmental stages. The disease index of T(1-T(3 generation was lower than 19, significantly (P<0.05 better than the negative control line z99668. After treatment with 250 mg/L VD-toxins for 36 hours, DNA from negative control leaves was fragmented, whereas fragmentation in the transgenic leaf DNA did not occur. The percentage of cell death in transgenic lines increased by 7.11% after 60 mg/L VD-toxin treatment, which was less than that of the negative control lines's 21.27%. This indicates that p35 and op-iap gene expression partially protects cells from VD-toxin induced programmed cell death (PCD. CONCLUSION/SIGNIFICANCE: Verticillium dahliae can trigger plant cells to die through induction of a PCD mechanism involved in pathogenesis. This paper provides a potential strategy for engineering broad-spectrum necrotrophic disease resistance in plants.

  6. 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...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  7. Discovery of a new source of resistance to Fusarium oxysporum, cause of Fusarium wilt in Allium fistulosum, located on chromosome 2 of Allium cepa Aggregatum group.

    Science.gov (United States)

    Vu, Hoa Q; El-Sayed, Magdi A; Ito, Shin-Ichi; Yamauchi, Naoki; Shigyo, Masayoshi

    2012-11-01

    This study was carried out to evaluate the antifungal effect of Allium cepa Aggregatum group (shallot) metabolites on Fusarium oxysporum and to determine the shallot chromosome(s) related to Fusarium wilt resistance using a complete set of eight Allium fistulosum - shallot monosomic addition lines. The antifungal effects of hexane, butanol, and water extraction fractions from bulbs of shallot on 35 isolates of F. oxysporum were examined using the disc diffusion method. Only hexane and butanol fractions showed high antifungal activity. Shallot showed no symptom of disease after inoculation with F. oxysporum f. sp. cepae. The phenolic content of the roots and the saponin content of root exudates of inoculated shallot increased to much higher levels than those of the control at 3 days after inoculation. Application of freeze-dried shallot root exudates to seeds of A. fistulosum soaked in a spore suspension of F. oxysporum resulted in protection of seedlings against infection. Among eight monosomic addition lines and A. fistulosum, FF+2A showed the highest resistance to Fusarium wilt. This monosomic addition line also showed a specific saponin band derived from shallot on the thin layer chromatography profile of saponins in the eight monosomic addition lines. The chromosome 2A of shallot might possess some of the genes related to Fusarium wilt resistance.

  8. Proteomics of Fusarium oxysporum race 1 and race 4 reveals enzymes involved in carbohydrate metabolism and ion transport that might play important roles in banana Fusarium wilt.

    Science.gov (United States)

    Sun, Yong; Yi, Xiaoping; Peng, Ming; Zeng, Huicai; Wang, Dan; Li, Bo; Tong, Zheng; Chang, Lili; Jin, Xiang; Wang, Xuchu

    2014-01-01

    Banana Fusarium wilt is a soil-spread fungal disease caused by Fusarium oxysporum. In China, the main virulence fungi in banana are F. oxysporum race 1 (F1, weak virulence) and race 4 (F4, strong virulence). To date, no proteomic analyses have compared the two races, but the difference in virulence between F1 and F4 might result from their differentially expressed proteins. Here we report the first comparative proteomics of F1 and F4 cultured under various conditions, and finally identify 99 protein species, which represent 59 unique proteins. These proteins are mainly involved in carbohydrate metabolism, post-translational modification, energy production, and inorganic ion transport. Bioinformatics analysis indicated that among the 46 proteins identified from F4 were several enzymes that might be important for virulence. Reverse transcription PCR analysis of the genes for 15 of the 56 proteins revealed that their transcriptional patterns were similar to their protein expression patterns. Taken together, these data suggest that proteins involved in carbohydrate metabolism and ion transport may be important in the pathogenesis of banana Fusarium wilt. Some enzymes such as catalase-peroxidase, galactosidase and chitinase might contribute to the strong virulence of F4. Overexpression or knockout of the genes for the F4-specific proteins will help us to further understand the molecular mechanism of Fusarium-induced banana wilt.

  9. Progresses on Pathogens of Banana Fusarium Wilt:a Review%香蕉枯萎病病原菌的研究进展

    Institute of Scientific and Technical Information of China (English)

    李斌; 盛鸥; 李春雨; 魏岳荣; 左存武; 胡春华; 易干军; 罗充

    2013-01-01

    Fusarium wilt of banana (Musa spp.), caused by soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc), is one of the most serious and devastating diseases threatening the sustainable development of banana industry in the world. This review summarized the methodologies on isolation, incubation and identification of the pathogens of banana fusarium wilt, and highlighted recent findings relevant to classification and evolutionary relationships among the Foc vegetative compatibility groups (VCGs), and recent advances in molecular makers for rapid diagnosis of the pathogens. The present review may provide a reference guide to better understanding banana fusarium wilt for the researchers in China.%香蕉枯萎病是香蕉生产中最为严重、具有毁灭性的病害之一,已成为限制世界香蕉产业可持续发展的重要难题。本文根据国内外近年来香蕉枯萎病的研究概况,综述了病原菌的分离、培养和鉴定等基本研究方法,以及病原菌的分类、进化关系和分子鉴定等研究进展,以期能为中国香蕉枯萎病研究工作者提供借鉴,尽早解决香蕉枯萎病难题。

  10. Fermentation characteristics, chemical composition and fractionation of carbohydrates and crude protein of silage of elephant grass wilted or with addition of castor bean meal

    Directory of Open Access Journals (Sweden)

    Leandro Sampaio Oliveira Ribeiro

    2014-06-01

    Full Text Available The experiment was conducted to evaluate the concentrations of ammonia nitrogen, hydrogen potential, the losses of deriving the fermentative process, nutritional value, the fractioning of carbohydrates and protein the elephant grass silage wilted or not containing castor bean meal. The experimental design was completely randomized, with five treatments and with four replications: elephant grass wilted; elephant not wilted; elephant grass more castor bean meal (6%; elephant grass more castor bean meal (12% and elephant grass more castor bean meal (18%, the coproduct was added with base on natural matter. We adopted a specific mass of 600 kg/m3. The silage containing 18% castor bean meal showed higher (P0.05 among the silages with additives for fractions A+B1, B2 and C. For the protein fractioning, the fractions A and C decreased (P<0.05 with increase of the inclusion of castor bean meal, differently, of the fraction B1+B2 which increased. The castor bean stands out as a good additive in silage of elephant grass to reduce moisture and improve the fermentation characteristics of silages also was effective in increasing the protein value of silages, especially when using the dose 18%.

  11. 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 ...

  12. Identificação de progênies de tomateiro resistentes à murcha-bacteriana Identification of tomato progenies for resistance to bacterial wilt

    OpenAIRE

    Silveira,Elineide B.; Andréa M.A. Gomes; Edinardo Ferraz; Maranhão,Elizabeth A. A.; Rosa L.R. Mariano

    1999-01-01

    Uma amostra de 660 plantas de uma população F6 de tomateiro, obtida pelo cruzamento das cultivares CL5915-93 (moderadamente resistente) e IPA-6 (suscetível) foi avaliada para resistência a Ralstonia solanacearum em condições de campo (28 ± 4ºC e UR 70 ± 5,5%), em março de 1996 na UFRPE. Plantas com 20 dias foram inoculadas com a biovar III do patógeno pela deposição de 5 ml de uma suspensão (5x10(8) UFC/ml) na base de cada planta, duas horas antes do transplantio para canteiros no campo. As a...

  13. Occurrence and Prevention of Maize Bacterial Wilt%玉米青枯病大面积发生与防治建议

    Institute of Scientific and Technical Information of China (English)

    白石; 赵杨; 李士东

    2007-01-01

    玉米青枯病也叫玉米茎基腐病,是由几种镰刀菌(Fusarium spp.)或腐霉菌(Pythium spp.)引起的危害玉米根和茎基部的一类土传真菌病害,是对玉米生产影响较重的病害。在我国各玉米产区均有不同程度发生,病株率为10%~20%,普遍发生在玉米穗灌浆期。青枯病一旦发生,全株很快枯死,一般需要5~8d,快的只需2~3d。严重影响了玉米产量。

  14. CONTROL OF VIRAL DISEASES TRANSMITTED IN A PERSISTENT MANNER BY THRIPS IN PEPPER (TOMATO SPOTTED WILT VIRUS).

    Science.gov (United States)

    Fanigliulo, A; Viggiano, A; Gualco, A; Crescenzi, A

    2014-01-01

    Tomato spotted wilt disease is caused by Tomato Spotted Wilt Virus (TSWV) (Tospovirus, Bunyaviridae), a virus that severely damages and reduces the yield of many economically important plants worldwide and actually it is a major disease affecting the production of tomato and pepper in Italy. Due to the non-predictive nature of its outbreaks combined with the lack of forecasting, adoption of preventive measures have not always been practical, in fact the disease cycle has proven to be extremely difficult to break because of the wide and often overlapping host range of both the virus and the thrips vectors, which transmit the virus in a persistent, circulative, and propagative manner. Moreover recently, resistance breaking (RB) isolates of TSWV that overcome the resistance conferred by the Tsw gene in different pepper hybrids have been recovered in different locations in Italy and also in Brazil, USA, Spain and Australia, and this occurrence raises the question on the importance of a new approach of integrated pest management for TSWV management, including both control of its insect vector and the induction of the plant's resistance against viral infection. In this perspective, a study was performed in 2012 and 2013 with the purpose of evaluating the efficacy of the insecticide Cyantraniliprole alone or combined with Acibenzolar-S-Methyl (ASM), inducer of systemic acquired resistance, in the control of tomato spotted wilt disease in pepper. The experiment was performed in laboratory, in a thermo-conditioned greenhouse, into separate insect-proof cages and consisted of 5 treatments and 2 applications (plus a pre-transplant application for treatments were ASM was used. Variables were the mode of application of ASM in pre-transplant (by foliar or by drench) and the duration of the exposure time of the treated plants to viruliferous insects. Pepper cv. Corno di Toro, devoid of any resistance to TSWV, was used. Plants were observed daily to record any symptom induced by

  15. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  16. 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 ...

  17. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  18. 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.

  19. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    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....... 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....

  20. [Diagnosis of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    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 H2O2-producing 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. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  1. 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

  2. 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

    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 intermediate resistance, no highly resistance. Comprehensive analysis, M11 and M25 exhibited intermediate resistance both on fusarium wilt disease of No. 1 and No. 4 physiological races.%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

  3. Species or Genotypes? Reassessment of Four Recently Described Species of the Ceratocystis Wilt Pathogen, Ceratocystis fimbriata, on Mangifera indica.

    Science.gov (United States)

    Oliveira, Leonardo S S; Harrington, Thomas C; Ferreira, Maria A; Damacena, Michelle B; Al-Sadi, Abdullah M; Al-Mahmooli, Issa H S; Alfenas, Acelino C

    2015-09-01

    Ceratocystis wilt is among the most important diseases on mango (Mangifera indica) in Brazil, Oman, and Pakistan. The causal agent was originally identified in Brazil as Ceratocystis fimbriata, which is considered by some as a complex of many cryptic species, and four new species on mango trees were distinguished from C. fimbriata based on variation in internal transcribed spacer sequences. In the present study, phylogenetic analyses using DNA sequences of mating type genes, TEF-1α, and β-tubulin failed to identify lineages corresponding to the four new species names. Further, mating experiments found that the mango isolates representing the new species were interfertile with each other and a tester strain from sweet potato (Ipomoea batatas), on which the name C. fimbriata is based, and there was little morphological variation among the mango isolates. Microsatellite markers found substantial differentiation among mango isolates at the regional and population levels, but certain microsatellite genotypes were commonly found in multiple populations, suggesting that these genotypes had been disseminated in infected nursery stock. The most common microsatellite genotypes corresponded to the four recently named species (C. manginecans, C. acaciivora, C. mangicola, and C. mangivora), which are considered synonyms of C. fimbriata. This study points to the potential problems of naming new species based on introduced genotypes of a pathogen, the value of an understanding of natural variation within and among populations, and the importance of phenotype in delimiting species.

  4. Characterization of a New Tomato Spotted Wilt Virus Isolates Found in Hippeastrum hybridum (Hort. Plants in Poland

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    Berniak Hanna

    2016-06-01

    Full Text Available Two Tomato spotted wilt virus (TSWV isolates H1 and H2 found in Hippeastrum hybridum plants were characterized based on biological, serological, and molecular properties. Virus isolates showed differences in symptom expression – H1 isolate displayed severe necrotic spots and patterns, whereas mild mosaic symptoms were observed on H2-infected H. hybridum plants. Both TSWV isolates showed comparable reactivity with TSWV-specific antibodies and they induced similar symptoms on herbaceous indicator plants, but some differences between these isolates were detected at the nucleotide sequence level of genomic S and M ssRNAs segment fragments. The nucleotide sequences encoding nucleocapsid (N and nonstructural (NSs and NSm proteins showed 98.2%, 97.5%, and 96.5% identity, respectively. Phylogenetic analysis of N and NSs sequences conducted for tested isolates and 31 TSWV isolates included for comparison revealed that H1 and H2 isolates fell into the same cluster and they were grouped together with isolates found previously in different vegetables, ornamentals, and weeds. When NSm ORF was analyzed, the tested isolates formed a separate cluster: H1 isolate showed the highest affinity with TSWV isolates infecting chrysanthemum and pepper plants, whereas H2 isolate was most closely related to other virus isolates found in sweet pepper and tomatoes. These results indicate that both isolates were reassortants between different virus isolates, and represented two novel genetic patterns of TSWV.

  5. Members of Gammaproteobacteria as indicator species of healthy banana plants on Fusarium wilt-infested fields in Central America

    Science.gov (United States)

    Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

    2017-01-01

    Culminating in the 1950’s, bananas, the world’s most extensive perennial monoculture, suffered one of the most devastating disease epidemics in history. In Latin America and the Caribbean, Fusarium wilt (FW) caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (FOC), forced the abandonment of the Gros Michel-based export banana industry. Comparative microbiome analyses performed between healthy and diseased Gros Michel plants on FW-infested farms in Nicaragua and Costa Rica revealed significant shifts in the gammaproteobacterial microbiome. Although we found substantial differences in the banana microbiome between both countries and a higher impact of FOC on farms in Costa Rica than in Nicaragua, the composition especially in the endophytic microhabitats was similar and the general microbiome response to FW followed similar rules. Gammaproteobacterial diversity and community members were identified as potential health indicators. Healthy plants revealed an increase in potentially plant-beneficial Pseudomonas and Stenotrophomonas, while diseased plants showed a preferential occurrence of Enterobacteriaceae known for their plant-degrading capacity. Significantly higher microbial rhizosphere diversity found in healthy plants could be indicative of pathogen suppression events preventing or minimizing disease expression. This first study examining banana microbiome shifts caused by FW under natural field conditions opens new perspectives for its biological control. PMID:28345666

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

    Science.gov (United States)

    Thatcher, Louise F.; Gao, Ling-Ling; Singh, Karam B.

    2016-01-01

    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. PMID:27135231

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

    Science.gov (United States)

    Thatcher, Louise F; Gao, Ling-Ling; Singh, Karam B

    2016-02-05

    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.

  8. Comparative mapping of Raphanus sativus genome using Brassica markers and quantitative trait loci analysis for the Fusarium wilt resistance trait.

    Science.gov (United States)

    Yu, Xiaona; Choi, Su Ryun; Ramchiary, Nirala; Miao, Xinyang; Lee, Su Hee; Sun, Hae Jeong; Kim, Sunggil; Ahn, Chun Hee; Lim, Yong Pyo

    2013-10-01

    Fusarium wilt (FW), caused by the soil-borne fungal pathogen Fusarium oxysporum is a serious disease in cruciferous plants, including the radish (Raphanus sativus). To identify quantitative trait loci (QTL) or gene(s) conferring resistance to FW, we constructed a genetic map of R. sativus using an F2 mapping population derived by crossing the inbred lines '835' (susceptible) and 'B2' (resistant). A total of 220 markers distributed in 9 linkage groups (LGs) were mapped in the Raphanus genome, covering a distance of 1,041.5 cM with an average distance between adjacent markers of 4.7 cM. Comparative analysis of the R. sativus genome with that of Arabidopsis thaliana and Brassica rapa revealed 21 and 22 conserved syntenic regions, respectively. QTL mapping detected a total of 8 loci conferring FW resistance that were distributed on 4 LGs, namely, 2, 3, 6, and 7 of the Raphanus genome. Of the detected QTL, 3 QTLs (2 on LG 3 and 1 on LG 7) were constitutively detected throughout the 2-year experiment. QTL analysis of LG 3, flanked by ACMP0609 and cnu_mBRPGM0085, showed a comparatively higher logarithm of the odds (LOD) value and percentage of phenotypic variation. Synteny analysis using the linked markers to this QTL showed homology to A. thaliana chromosome 3, which contains disease-resistance gene clusters, suggesting conservation of resistance genes between them.

  9. KEBERADAAN DYSMICOCCUS BREVIPES (COCKERELL (HEMIPTERA: PSEUDOCOCCIDAE SEBAGAI VEKTOR PINEAPPLE MEALYBUG WILT-ASSOCIATED VIRUS (PMWAV PADA TANAMAN NANAS

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    Dewi Sartiami

    2006-04-01

    Full Text Available Mealybug can almost be found in all pineapple fields (Ananas comosus (Linnaeus. The insect is known to be a vector of Pineapple Mealybug wilt-associated Virus (PMWaV. The insect samples taken from pineapple in Bunihayu, Jalancagak, Subang, West Java, were identified in laboratory. Mealybug-ant symbionts were also taken. The ability of this ant to carry the mealybugs from colony reared on kabocha (Cucurbita maxima to pineapple was also tested at green house level. Only one spesies of mealybug was found on pineapple, i.e. Dysmicoccus brevipes (Cockerell (Hemiptera: Pseudococcidae. The mealybugs were found to colonize root, basal of stem and the leaf. Eight ant species were found to be associated with mealybug. There are four species belongs to Pseudolasius genera, two species Cardiocondyla genera, Paratrechina sp. and Dorylus sp. Paratrechina sp. showed the ability to carry D. brevipes from kabocha population to pineapple. Therefore the ants should also be controlled in the total management of PMWav.

  10. 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.

  11. Screening for Pseudomonas and Bacillus antagonistic rhizobacteria strains for the biocontrol of Fusarium wilt of chickpea

    Directory of Open Access Journals (Sweden)

    Hannane Abed

    2016-07-01

    Full Text Available The aim of this work is to study the ability of several isolates belonging to Rhizobacteria (Pseudomonas and Bacillus collected from several chickpea growing areas in Algeria, to control the mycelium growth of Fusarium oxysporum f. sp. ciceris. Interesting isolates were characterized for their morphological characteristics, physiological and biochemical activities as potential bio-control agent. Fungal inhibition tests were performed using plate assay and each isolate were tested for the production of protease, cyanide hydrogen, indole acetic acid, antifungal volatile and extracellular compound. According to API 50 CH, we are able to identify six Bacillus species (B. subtilis, B. circulans, B. lentus, B. aneurinilyticus, B. firmus, B. licheniformis; and with API 20NE test we have identified three Pseudomonas species (P. aeruginosa, P. luteola, P. fluorescens. The ability of bacterial isolates was varied in production of Protease, Gelatinase, Amylase, Cellulase, Acid Indole acetic, Lipase, Catalase and Cyanid Hydrogen. This is traduced in different rate of inhibition growth due to various extracellular compounds, where B61 (Bacillus aneurinilyticus and P39 (Pseudomonas luteola and P70 (Pseudomonas fluorescens were the most efficient with 77 and 55.5% respectively, while B39 (Bacillus firmus and P41 (Pseudomonas luteola were the most efficient by volatile compounds with 70.5 and 77.5% respectively. Our results indicate that these bacteria isolates can be used in the biocontrol of Fusarium oxysporum f. sp. ciceris.

  12. The bacterial lipocalins.

    Science.gov (United States)

    Bishop, R E

    2000-10-18

    The lipocalins were once regarded as a eukaryotic protein family, but new members have been recently discovered in bacteria. The first bacterial lipocalin (Blc) was identified in Escherichia coli as an outer membrane lipoprotein expressed under conditions of environmental stress. Blc is distinguished from most lipocalins by the absence of intramolecular disulfide bonds, but the presence of a membrane anchor is shared with two of its closest homologues, apolipoprotein D and lazarillo. Several common features of the membrane-anchored lipocalins suggest that each may play an important role in membrane biogenesis and repair. Additionally, Blc proteins are implicated in the dissemination of antibiotic resistance genes and in the activation of immunity. Recent genome sequencing efforts reveal the existence of at least 20 bacterial lipocalins. The lipocalins appear to have originated in Gram-negative bacteria and were probably transferred horizontally to eukaryotes from the endosymbiotic alpha-proteobacterial ancestor of the mitochondrion. The genome sequences also reveal that some bacterial lipocalins exhibit disulfide bonds and alternative modes of subcellular localization, which include targeting to the periplasmic space, the cytoplasmic membrane, and the cytosol. The relationships between bacterial lipocalin structure and function further illuminate the common biochemistry of bacterial and eukaryotic cells.

  13. Isolation and Preliminary Identification of Antagonistic Bacterium against Fusarium wilt of Cucumber and Watermelon%黄瓜、西瓜枯萎病拮抗细菌的初步分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    吴洪生; 周晓冬; 李鹤; 刘正柱; 闫霜; 刘小雪; 王增辉; 孔祥云

    2013-01-01

    To screen and isolate the antagonistic bacteria that can control cucumber and watermelon wilt pathogen Fusarium oxysporum from the soil,the antagonistic bacteria from soil samples in the greenhouse where pepper was planted and could antagonize cucumber and watermelon wilt pathogen Fusarium oxysporum were conducted for the plate confrontation experiment.The results showed that,LX6,LX7,LX12,LX13 bacterial strains could antagonize Fusarium oxysporum of cucumber and watermelon and had clear inhibition zone;the inhibition zone diameter arrived at 19.3,18.2,17.4,25.5 mm and 16.2,15.0,15.9,14.8 mm after 96 h.In a 30-day-pot-test,control rates against F.oxysporum of LX6 strain treated in cucumber and watermelon were 85.3 % and 81.2 %,respectively.The results of plate culture,microscopy,16S rDNA-based molecular identification (1650bp fragment) and physiological and biochemical characterization showed that the isolated antagonistic bacterium was Bacillus amyloliquifacience and its molecular weight of 16sDNA fragment was 1650 bp.%为了从土壤中筛选能同时抑制黄瓜、西瓜枯萎病的致病菌尖孢镰刀菌的天然拮抗菌,从种植辣椒的大棚土样中分离培养多种能同时拮抗黄瓜和西瓜枯萎病的拮抗细菌,经平板对峙实验,从辣椒土样中分离出编号为LX6、LX7、LX12、LX13的细菌菌株对黄瓜和西瓜尖孢镰刀菌有明显的拮抗作用,抑菌圈显著,96h抑菌圈直径分别达到19.3、18.2、17.4、25.5 mm和16.2、15.0、15.9、14.8 mm;盆栽试验,拮抗菌LX6对黄瓜和西瓜枯萎病30 d的防治效果分别达到85.3%和81.2%.拮抗效果最显著的LX6菌株做分子生物学的进一步鉴定.经平板培养菌落特征、镜检、16S DNA分子鉴定和生理生化特征鉴定表明,所分离的拮抗菌LX6为淀粉液化芽孢杆菌(Bacillus amyloliquefaciens),16sDNA片段分子量为1650bp.

  14. Bacterial glycosyltransferase toxins.

    Science.gov (United States)

    Jank, Thomas; Belyi, Yury; Aktories, Klaus

    2015-12-01

    Mono-glycosylation of host proteins is a common mechanism by which bacterial protein toxins manipulate cellular functions of eukaryotic target host cells. Prototypic for this group of glycosyltransferase toxins are Clostridium difficile toxins A and B, which modify guanine nucleotide-binding proteins of the Rho family. However, toxin-induced glycosylation is not restricted to the Clostridia. Various types of bacterial pathogens including Escherichia coli, Yersinia, Photorhabdus and Legionella species produce glycosyltransferase toxins. Recent studies discovered novel unexpected variations in host protein targets and amino acid acceptors of toxin-catalysed glycosylation. These findings open new perspectives in toxin as well as in carbohydrate research.

  15. Seizures Complicating Bacterial Meningitis

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    J Gordon Millichap

    2004-09-01

    Full Text Available The clinical data of 116 patients, 1 month to <5 years of age, admitted for bacterial meningitis, and grouped according to those with and without seizures during hospitalization, were compared in a study at Buddhist Dalin Tzu Chi General Hospital, Chang Gung Memorial Hospital and other centers in Taiwan.

  16. 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.

  17. 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.

  18. Genetic Dissection of Novel QTLs for Resistance to Leaf Spots and Tomato Spotted Wilt Virus in Peanut (Arachis hypogaea L.)

    Science.gov (United States)

    Pandey, Manish K.; Wang, Hui; Khera, Pawan; Vishwakarma, Manish K.; Kale, Sandip M.; Culbreath, Albert K.; Holbrook, C. Corley; Wang, Xingjun; Varshney, Rajeev K.; Guo, Baozhu

    2017-01-01

    Peanut is an important crop, economically and nutritiously, but high production cost is a serious challenge to peanut farmers as exemplified by chemical spray to control foliar diseases such as leaf spots and thrips, the vectors of tomato spotted wilt virus (TSWV). The objective of this research was to map the quantitative trait loci (QTLs) for resistance to leaf spots and TSWV in one recombinant inbred line (RIL) mapping population of “Tifrunner × GT-C20” for identification of linked markers for marker-assisted breeding. Here, we report the improved genetic linkage map with 418 marker loci with a marker density of 5.3 cM/loci and QTLs associated with multi-year (2010–2013) field phenotypes of foliar disease traits, including early leaf spot (ELS), late leaf spot (LLS), and TSWV. A total of 42 QTLs were identified with phenotypic variation explained (PVE) from 6.36 to 15.6%. There were nine QTLs for resistance to ELS, 22 QTLs for LLS, and 11 QTLs for TSWV, including six, five, and one major QTLs with PVE higher than 10% for resistance to each disease, respectively. Of the total 42 QTLs, 34 were mapped on the A sub-genome and eight mapped on the B sub-genome suggesting that the A sub-genome harbors more resistance genes than the B sub-genome. This genetic linkage map was also compared with two diploid peanut physical maps, and the overall co-linearity was 48.4% with an average co-linearity of 51.7% for the A sub-genome and 46.4% for the B sub-genome. The identified QTLs associated markers and potential candidate genes will be studied further for possible application in molecular breeding in peanut genetic improvement for disease resistance. PMID:28197153

  19. 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.

  20. Tomato spotted wilt virus benefits a non-vector arthropod, Tetranychus urticae, by modulating different plant responses in tomato.

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    Punya Nachappa

    Full Text Available The interaction between plant viruses and non-vector arthropod herbivores is poorly understood. However, there is accumulating evidence that plant viruses can impact fitness of non-vector herbivores. In this study, we used oligonucleotide microarrays, phytohormone, and total free amino acid analyses to characterize the molecular mechanisms underlying the interaction between Tomato spotted wilt virus (TSWV and a non-vector arthropod, twospotted spider mite (Tetranychusurticae, on tomato plants, Solanumlycopersicum. Twospotted spider mites showed increased preference for and fecundity on TSWV-infected plants compared to mock-inoculated plants. Transcriptome profiles of TSWV-infected plants indicated significant up-regulation of salicylic acid (SA-related genes, but no apparent down-regulation of jasmonic acid (JA-related genes which could potentially confer induced resistance against TSM. This suggests that there was no antagonistic crosstalk between the signaling pathways to influence the interaction between TSWV and spider mites. In fact, SA- and JA-related genes were up-regulated when plants were challenged with both TSWV and the herbivore. TSWV infection resulted in down-regulation of cell wall-related genes and photosynthesis-associated genes, which may contribute to host plant susceptibility. There was a three-fold increase in total free amino acid content in virus-infected plants compared to mock-inoculated plants. Total free amino acid content is critical for arthropod nutrition and may, in part, explain the apparent positive indirect effect of TSWV on spider mites. Taken together, these data suggest that the mechanism(s of increased host suitability of TSWV-infected plants to non-vector herbivores is complex and likely involves several plant biochemical processes.

  1. 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.

  2. 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.

  3. 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.

  4. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  5. Bacterial Colony Optimization

    Directory of Open Access Journals (Sweden)

    Ben Niu

    2012-01-01

    Full Text Available This paper investigates the behaviors at different developmental stages in Escherichia coli (E. coli lifecycle and developing a new biologically inspired optimization algorithm named bacterial colony optimization (BCO. BCO is based on a lifecycle model that simulates some typical behaviors of E. coli bacteria during their whole lifecycle, including chemotaxis, communication, elimination, reproduction, and migration. A newly created chemotaxis strategy combined with communication mechanism is developed to simplify the bacterial optimization, which is spread over the whole optimization process. However, the other behaviors such as elimination, reproduction, and migration are implemented only when the given conditions are satisfied. Two types of interactive communication schemas: individuals exchange schema and group exchange schema are designed to improve the optimization efficiency. In the simulation studies, a set of 12 benchmark functions belonging to three classes (unimodal, multimodal, and rotated problems are performed, and the performances of the proposed algorithms are compared with five recent evolutionary algorithms to demonstrate the superiority of BCO.

  6. Bacterial assays for recombinagens.

    Science.gov (United States)

    Hoffmann, G R

    1992-12-01

    Two principal strategies have been used for studying recombinagenic effects of chemicals and radiation in bacteria: (1) measurement of homologous recombination involving defined alleles in a partially diploid strain, and (2) measurement of the formation and loss of genetic duplications in the bacterial chromosome. In the former category, most methods involve one allele in the bacterial chromosome and another in a plasmid, but it is also possible to detect recombination between two chromosomal alleles or between two extrachromosomal alleles. This review summarizes methods that use each of these approaches for detecting recombination and tabulates data on agents that have been found to be recombinagenic in bacteria. The assays are discussed with respect to their effectiveness in testing for recombinagens and their potential for elucidating mechanisms underlying recombinagenic effects.

  7. Bacterial transformation of terpenoids

    Science.gov (United States)

    Grishko, V. V.; Nogovitsina, Y. M.; Ivshina, I. B.

    2014-04-01

    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.

  8. Spontaneous bacterial peritonitis

    OpenAIRE

    Al Amri Saleh

    1995-01-01

    Spontaneous bacterial peritonitis (SBP) is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is...

  9. Modelling bacterial speciation

    OpenAIRE

    2006-01-01

    A central problem in understanding bacterial speciation is how clusters of closely related strains emerge and persist in the face of recombination. We use a neutral Fisher–Wright model in which genotypes, defined by the alleles at 140 house-keeping loci, change in each generation by mutation or recombination, and examine conditions in which an initially uniform population gives rise to resolved clusters. Where recombination occurs at equal frequency between all members of the population, we o...

  10. Adaptive Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2011-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a recently developed nature-inspired optimization algorithm, which is based on the foraging behavior of E. coli bacteria. Up to now, BFO has been applied successfully to some engineering problems due to its simplicity and ease of implementation. However, BFO possesses a poor convergence behavior over complex optimization problems as compared to other nature-inspired optimization techniques. This paper first analyzes how the run-length unit parameter of BFO controls the exploration of the whole search space and the exploitation of the promising areas. Then it presents a variation on the original BFO, called the adaptive bacterial foraging optimization (ABFO, employing the adaptive foraging strategies to improve the performance of the original BFO. This improvement is achieved by enabling the bacterial foraging algorithm to adjust the run-length unit parameter dynamically during algorithm execution in order to balance the exploration/exploitation tradeoff. The experiments compare the performance of two versions of ABFO with the original BFO, the standard particle swarm optimization (PSO and a real-coded genetic algorithm (GA on four widely-used benchmark functions. The proposed ABFO shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  11. Neglected bacterial zoonoses.

    Science.gov (United States)

    Chikeka, I; Dumler, J S

    2015-05-01

    Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. Although many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which broad-spectrum diagnoses are actively sought. This review will focus attention on leptospirosis, relapsing fever borreliosis and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control.

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

    Science.gov (United States)

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

    2016-04-22

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

  13. The Use of Genetic Variability Analysis of Fusarium oxysporum f. sp. cubense for Breeding Resistance of Banana against Fusarium Wilting Disease

    Directory of Open Access Journals (Sweden)

    Faria Ruhana

    2015-11-01

    Full Text Available Fusarium wilting on banana crop caused by Fusarium oxysporum f. sp. cubense is one of the important disease in banana plant in Indonesia. This disease can cause plant to wilt and die, therefore bringing loss to the banana farmer and entrepreneur. F. oxysporum f. sp. cubense genetic variability analysis techniques can be done by in vitro or in vivo. One of F.oxysporum f. sp. cubense genetic variability analysis techniques by in vitro is RAPD-PCR. In this research, analysis is continued with pathogen test. Genetic variability analysis by in vivo is needed to determine the level of pathogen and the race. The result of genetic variability techniques by RAPD-PCR done by this writer indicates that there is a big relation/link difference between isolats from different island. Isolat from Mojokerto (East Java is 100% genetically different compared to the one from West Sumatera. Later, result of pathogen test shows that Pisang Ambon Kuning is the most resilient compared to Pisang Raja and William Cavendish. Based on the level of pathogen, there are two race grouping, which are race 1 that attacks Pisang Ambon Kuning and race 4 that attacks Pisang Raja and William Cavendish. Scott-Knott analysis on 26 isolats results in no real difference between isolats tested.

  14. 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.

  15. 山西棉田黄萎病菌致病力差异研究%Research on Virulence Difference of Verticillium Wilt in Shanxi

    Institute of Scientific and Technical Information of China (English)

    许爱玲; 段国琪; 张战备; 沈红星; 张开峰; 解广田

    2013-01-01

    In the same piece of cotton field, different resistance transgenic cotton varieties are planted. Using choice function of different resistant cotton varieties to Verticillium wilt bacteria, Vertkillium wilt strains had been gotten from different breed separations; In the greenhouse, using two different obvious disease resistance varieties pathogenic force were measured to determine whether there are different pathogenic force strains in the same piece of cotton field.%在同一块棉田中种植不同抗病性的转基因抗虫棉,利用不同抗性的棉花品种对棉花黄萎病菌的选择作用,从不同品种上分离获得不同的黄萎病菌系,并在温室中采用2个抗病性差异明显的品种对其致病力进行测定,以确定同一块棉田中是否存在不同致病力菌系.结果表明,不同抗病性品种上分离获得的病原菌致病力存在显著差异,同一块棉田中存在各种致病力菌系.

  16. Phenylacetic acid is ISR determinant produced by Bacillus fortis IAGS162, which involves extensive re-modulation in metabolomics of tomato to protect against fusarium wilt.

    Directory of Open Access Journals (Sweden)

    Waheed eAkram

    2016-04-01

    Full Text Available B. 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 again treated with PAA and fungal pathogen in either 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 contribute to resistance against fungal pathogens through dynamic reprogramming of plant pathways that are functionally correlated with defense responses.

  17. 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.

  18. 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

  19. Mechanisms of Action and Dose-Response Relationships Governing Biological Control of Fusarium Wilt of Tomato by Nonpathogenic Fusarium spp.

    Science.gov (United States)

    Larkin, R P; Fravel, D R

    1999-12-01

    ABSTRACT Three isolates of nonpathogenic Fusarium spp. (CS-1, CS-20, and Fo47), previously shown to reduce the incidence of Fusarium wilt diseases of multiple crops, were evaluated to determine their mechanisms of action and antagonist-pathogen inoculum density relationships. Competition for nutrients, as represented by a reduction in pathogen saprophytic growth in the presence of the biocontrol isolates, was observed to be an important mechanism of action for isolate Fo47, but not for isolates CS-1 and CS-20. All three biocontrol isolates demonstrated some degree of induced systemic resistance in tomato (Lycopersicon esculentum) and watermelon (Citrullus lanatus) plants, as determined by split-root tests, but varied in their relative abilities to reduce disease. Isolate CS-20 provided the most effective control (39 to 53% disease reduction), while Fo47 provided the least effective control (23 to 25% reduction) in split-root tests. Dose-response relationships also differed considerably among the three biocon-trol isolates, with CS-20 significantly reducing disease incidence at antagonist doses as low as 100 chlamydospores per g of soil (cgs) and at pathogen densities up to 10(5) cgs. Isolate CS-1 also was generally effective at antagonist densities of 100 to 5,000 cgs, but only when pathogen densities were below 10(4) cgs. Isolate Fo47 was effective only at antagonist densities of 10(4) to 10(5) cgs, regardless of pathogen density. Epidemiological dose-response models (described by linear, negative exponential, hyperbolic saturation [HS], and logistic [LG] functions) fit to the observed data were used to quantify differences among the biocontrol isolates and establish biocontrol characteristics. Each isolate required a different model to best describe its dose-response characteristics, with the HS/HS, LG/HS, and LG/LG models (pathogen/biocontrol components) providing the best fit for isolates CS-1, CS-20, and Fo47, respectively. Model parameters (defining effective

  20. Trichoderma asperellum strain T34 controls Fusarium wilt disease in tomato plants in soilless culture through competition for iron.

    Science.gov (United States)

    Segarra, Guillem; Casanova, Eva; Avilés, Manuel; Trillas, Isabel

    2010-01-01

    Trichoderma asperellum strain T34 has been reported to control the disease caused by Fusarium oxysporum f.sp. lycopersici (Fol) on tomato plants. To study the importance of iron concentration in the growth media for the activity and competitiveness of T34 and the pathogen, we tested four iron concentrations in the nutrient solution [1, 10, 100, and 1000 microM provided as EDTA/Fe(III)] in a biological control experiment with T34 and Fol in tomato plants. The reduction of the Fusarium-infected shoot by T34 was only significant at 10 microM Fe. We hypothesized that Fe competition is one of the key factors in the biocontrol activity exerted by T34 against Fol, as an increase in Fe concentration over 10 microM would lead to the suppression of T34 siderophore synthesis and thus inhibition of Fe competition with Fol. T34 significantly reduced the populations of Fol at all the doses of Fe assayed. In contrast, Fol enhanced the populations of T34 at 1 and 10 microM Fe. Nevertheless, several plant physiological parameters like net CO(2) assimilation (A), stomatal conductance (g(s)), relative quantum efficiency of PSII (Phi(PSII)), and efficiency of excitation energy capture by open PSII reactive centers (Fv'/Fm') demonstrated the protection against Fol damage by treatment with T34 at 100 microM Fe. The first physiological parameter affected by the disease progression was g(s). Plant dry weight was decreased by Fe toxicity at 100 and 1,000 microM. T34-treated plants had significantly greater heights and dry weights than control plants at 1,000 microM Fe, even though T34 did not reduce the Fe content in leaves or stems. Furthermore, T34 enhanced plant height even at the optimal Fe concentration (10 microM) compared to control plants. In conclusion, T. asperellum strain T34 protected tomato plants from both biotic (Fusarium wilt disease) and abiotic stress [Fe(III) toxic effects].

  1. Bacterial chromosome segregation.

    Science.gov (United States)

    Possoz, Christophe; Junier, Ivan; Espeli, Olivier

    2012-01-01

    Dividing cells have mechanisms to ensure that their genomes are faithfully segregated into daughter cells. In bacteria, the description of these mechanisms has been considerably improved in the recent years. This review focuses on the different aspects of bacterial chromosome segregation that can be understood thanks to the studies performed with model organisms: Escherichia coli, Bacillus subtilis, Caulobacter crescentus and Vibrio cholerae. We describe the global positionning of the nucleoid in the cell and the specific localization and dynamics of different chromosomal loci, kinetic and biophysic aspects of chromosome segregation are presented. Finally, a presentation of the key proteins involved in the chromosome segregation is made.

  2. 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...

  3. Spontaneous bacterial peritonitis

    Directory of Open Access Journals (Sweden)

    Al Amri Saleh

    1995-01-01

    Full Text Available Spontaneous bacterial peritonitis (SBP is an infection of the ascitic fluid without obvious intra-abdominal source of sepsis; usually complicates advanced liver disease. The pathogenesis of the disease is multifactorial: low ascitic protein-content, which reflects defi-cient ascitic fluid complement and hence, reduced opsonic activity is thought to be the most important pathogenic factor. Frequent and prolonged bacteremia has been considered as another pertinent cause of SBP. This disease is associated with high mortality and recurrence. Therefore, orompt recognition and institution of therapy and plan of prophylaxis is vital.

  4. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte;

    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 Par......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....

  5. 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.

  6. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  7. 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.

  8. 晾晒和添加剂对白羊草青贮的影响%Effects of Wilting and Additives on Old World Bluestem

    Institute of Scientific and Technical Information of China (English)

    吴兆海; 梁超; 王永新; 高文俊; 玉柱; 孙启忠; 白春生; 许庆方

    2012-01-01

    为探究含水量和添加剂对白羊草(Bothriochloa ischaemum)青贮的影响,以抽穗期新鲜的和晾晒的白羊草为原料,分别设计对照、添加甲酸(6 mL·kg-1)或蔗糖(2%)处理,袋装密封青贮360 d后取样分析.结果表明:晾晒处理白羊草青贮饲料的pH较高,乳酸和氨态氮含量极显著下降(P<0.01);添加蔗糖或甲酸能够改善白羊草青贮饲料的发酵品质,甲酸或蔗糖均能够极显著降低白羊草青贮饲料的pH、乙酸和氨态氮含量(P<0.01),极显著提高乳酸含量(P<0.01);添加甲酸或蔗糖显著提高了白羊草青贮饲料的干物质保存率(P<0.05);青贮之后,硝酸盐含量下降.添加剂可改善白羊草青贮饲料的发酵品质,而白羊草晾晒后再进行添加剂青贮则效果更佳.%Effects of additives and moisture contents on old world bluestem silage were studied. Fresh and wilted old world bluestem in the heading stage were placed in sealed vacuum plastic bags with formic acid (6 mL · kg-1) 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 could improved silage fermentation quality that decreased pH, acetic acid and ammonia nitrogen contents and increased lactic acid contents of old world bluestem silage (P<0. 01). The dry matter recovery of silage was increased with additives (P<0. 05) and nitrate content was reduced after ensilaged. Generally, the silage fermentation quality of old world bluestem can be improved by adding either formic acid or sucrose, especially when the material was initially wilted.

  9. 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

  10. Epigenetics and bacterial infections.

    Science.gov (United States)

    Bierne, Hélène; Hamon, Mélanie; Cossart, Pascale

    2012-12-01

    Epigenetic mechanisms regulate expression of the genome to generate various cell types during development or orchestrate cellular responses to external stimuli. Recent studies highlight that bacteria can affect the chromatin structure and transcriptional program of host cells by influencing diverse epigenetic factors (i.e., histone modifications, DNA methylation, chromatin-associated complexes, noncoding RNAs, and RNA splicing factors). In this article, we first review the molecular bases of the epigenetic language and then describe the current state of research regarding how bacteria can alter epigenetic marks and machineries. Bacterial-induced epigenetic deregulations may affect host cell function either to promote host defense or to allow pathogen persistence. Thus, pathogenic bacteria can be considered as potential epimutagens able to reshape the epigenome. Their effects might generate specific, long-lasting imprints on host cells, leading to a memory of infection that influences immunity and might be at the origin of unexplained diseases.

  11. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed.

  12. 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.

  13. Proteomic analysis of conidia germination in Fusarium oxysporum f. sp. cubense tropical race 4 reveals new targets in ergosterol biosynthesis pathway for controlling Fusarium wilt of banana.

    Science.gov (United States)

    Deng, Gui-Ming; Yang, Qiao-Song; He, Wei-Di; Li, Chun-Yu; Yang, Jing; Zuo, Cun-Wu; Gao, Jie; Sheng, Ou; Lu, Shao-Yun; Zhang, Sheng; Yi, Gan-Jun

    2015-09-01

    Conidial germination is a crucial step of the soilborne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), a most important lethal disease of banana. In this study, a total of 3659 proteins were identified by isobaric tags for relative and absolute quantitation (iTRAQ)-based comparative proteomic approach, of which 1009 were differentially expressed during conidial germination of the fungus at 0, 3, 7, and 11 h. Functional classification and bioinformatics analysis revealed that the majority of the differentially expressed proteins are involved in six metabolic pathways. Particularly, all differential proteins involved in the ergosterol biosynthesis pathway were significantly upregulated, indicating the importance of the ergosterol biosynthesis pathway to the conidial germination of Foc TR4. Quantitative RT-PCR, western blotting, and in vitro growth inhibition assay by several categories of fungicides on the Foc TR4 were used to validate the proteomics results. Four enzymes, C-24 sterol methyltransferase (ERG6), cytochrome P450 lanosterol C-14α-demethylase (EGR11), hydroxymethylglutaryl-CoA synthase (ERG13), and C-4 sterol methyl oxidase (ERG25), in the ergosterol biosynthesis pathway were identified and verified, and they hold great promise as new targets for effective inhibition of Foc TR4 early growth in controlling Fusarium wilt of banana. To the best of our knowledge, this report represents the first comprehensive study on proteomics profiling of conidia germination in Foc TR4. It provides new insights into a better understanding of the developmental processes of Foc TR4 spores. More importantly, by host plant-induced gene silencing (HIGS) technology, the new targets reported in this work allow us to develop novel transgenic banana leading to high protection from Fusarium wilt and to explore more effective antifungal drugs against either individual or multiple target proteins of Foc TR4.

  14. Stable integration and expression of wasabi defensin gene in "Egusi" melon (Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot.

    Science.gov (United States)

    Ntui, Valentine Otang; Thirukkumaran, Gunaratnam; Azadi, Pejman; Khan, Raham Sher; Nakamura, Ikuo; Mii, Masahiro

    2010-09-01

    Production of "Egusi" melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer "Egusi" resistant to these diseases, cotyledonary explants of two "Egusi" genotypes, 'Ejagham' and NHC1-130, were transformed with Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary vector pEKH1. After co-cultivation for 3 days, infected explants were transferred to MS medium containing 100 mg l(-l) kanamycin to select transformed tissues. After 3 weeks of culture, adventitious shoots appeared directly along the edges of the explants. As much as 19 out of 52 (36.5%) and 25 out of 71 (35.2%) of the explants in genotype NHC1-130 and 'Ejagham', respectively, formed shoots after 6 weeks of culture. As much as 74% (14 out of 19) of the shoots regenerated in genotype NHC1-130 and 72% (18 out of 25) of those produced in genotype 'Ejagham' were transgenic. A DNA fragment corresponding to the wasabi defensin gene or the selection marker nptII was amplified by PCR from the genomic DNA of all regenerated plant clones rooted on hormone-free MS medium under the same selection pressure, suggesting their transgenic nature. Southern blot analysis confirmed successful integration of 1-5 copies of the transgene. RT-PCR, northern and western blot analyses revealed that wasabi defensin gene was expressed in transgenic lines. Transgenic lines showed increased levels of resistance to Alternaria solani, which causes Alternaria leaf spot and Fusarium oxysporum, which causes Fusarium wilt, as compared to that of untransformed plants.

  15. Foliar application of the leaf-colonizing yeast Pseudozyma churashimaensis elicits systemic defense of pepper against bacterial and viral pathogens

    Science.gov (United States)

    Lee, Gahyung; Lee, Sang-Heon; Kim, Kyung Mo; Ryu, Choong-Min

    2017-01-01

    Yeast associates with many plant parts including the phyllosphere, where it is subject to harsh environmental conditions. Few studies have reported on biological control of foliar pathogens by yeast. Here, we newly isolated leaf-colonizing yeasts from leaves of field-grown pepper plants in a major pepper production area of South Korea. The yeast was isolated using semi-selective medium supplemented with rifampicin to inhibit bacterial growth and its disease control capacity against Xanthomonas axonopodis infection of pepper plants in the greenhouse was evaluated. Of 838 isolated yeasts, foliar spray of Pseudozyma churashimaensis strain RGJ1 at 108 cfu/mL conferred significant protection against X. axonopodis and unexpectedly against Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus, and Broad bean wilt virus under field conditions. Direct antagonism between strain RGJ1 and X. axonopodis was not detected from co-culture assays, suggesting that disease is suppressed via induced resistance. Additional molecular analysis of the induced resistance marker genes Capsicum annuum Pathogenesis-Related (CaPR) 4 and CaPR5 indicated that strain RGJ1 elicited plant defense priming. To our knowledge, this study is the first report of plant protection against bacterial and viral pathogens mediated by a leaf-colonizing yeast and has potential for effective disease management in the field. PMID:28071648

  16. 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..

  17. 枯萎病菌毒素培养滤液对唐菖蒲幼苗毒性的初步研究%Poisoning effects of toxin culture filtrate of Fusarium wilt pathogen on seedling of gladiolus

    Institute of Scientific and Technical Information of China (English)

    胡颖慧; 龚束芳; 李彩华; 冯晓晓; 尚芬; 杨涛; 车代弟

    2012-01-01

    对唐菖蒲枯萎病菌进行了产毒培养基的筛选,研究毒素培养滤液对胚根生长的抑制作用、对幼苗根系活力的影响及对幼苗的致萎作用.结果表明:唐菖蒲枯萎病菌在Czapek培养基中培养15 d所产生的培养滤液对唐菖蒲胚根的抑制作用最强,胚根生长抑制率高达99.79%;而菌丝干重在PD培养基中培养13 d达到最高值l 242.27 mg;毒素培养滤液经121℃灭菌20 min后对唐菖蒲胚根仍有很强的抑制作用,表现出较高的热稳定性;与对照相比,毒素培养滤液能够显著降低唐菖蒲幼苗根系活力,随处理时间的延长和处理浓度的增加,萎蔫级数逐渐增加.说明枯萎病菌毒素培养滤液是唐菖蒲枯萎病的致病因子,可以利用其筛选唐菖蒲抗枯萎病品种.%Four kinds of culture media for gladiolus Fusarium wilt pathogen were used to produce culture filtrate. Poisoning effects of culture filtrate of gladiolus Fusarium wilt on radicles growth, root activity and seedling of gladiolus were studied. The results showed that the culture filtrate had the strongest inhibition effect on the radicle of gladiolus at the 15th day cultured in Czapek liquid medium and the inhibition ratio was 99. 79% . The optimum medium for hyphae growth was PD medium. The hyphae growth reached to maximum at the 13 th day. The culture filtrate possessed the capacity of thermal stability, which could inhibit the growth of radical after sterilized 20 min under 1211. The culture filtrate significantly inhibited activity of gladiolus root and caused wilting of seedling. With the extension of culturing time and concentration of culture filtrate,the wilting degree of seedlings increased. The above indicated the culture filtrate of gladiolus Fusarium wilt pathogen was pathogenic factor of gladiolus wilt, and it could be used to screen disease-resistance gladiolus variety.

  18. Bacterial degradation of aminopyrine.

    Science.gov (United States)

    Blecher, H; Blecher, R; Wegst, W; Eberspaecher, J; Lingens, F

    1981-11-01

    1. Four strains of bacteria growing with aminopyrine as sole source of carbon were isolated from soil and were identified as strains of Phenylobacterium immobilis. 2. Strain M13 and strain E, the type species of Phenylobacterium immobilis (DSM 1986), which had been isolated by enrichment with chloridazon (5-amino-4-chloro-2-phenyl-2H-pyridazin-3-one) were used to investigate the bacterial degradation of aminopyrine. 3. Three metabolites were isolated and identified as: 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydro-2,3-dihydroxy-4,6-cyc lohexadien-1-yl)-3H-pyrazol-3-one, 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-2-(2,3-dihydroxyphenyl)-3H-pyrazol-3 -one and 4-(dimethylamino)-1,2-dihydro-1,5-dimethyl-3H-pyrazol-3-one. 4. An enzyme extract from cells of strain m13 was shown to further metabolize the catechol derivative of aminopyrine, with the formation of 2-pyrone-6-carboxylic acid. 5. Results indicate that the benzene ring of aminopyrine is the principal site of microbial metabolism.

  19. 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.

  20. 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.

  1. Bacterial endocarditis prophylaxis.

    Science.gov (United States)

    Blanco-Carrión, Andrés

    2004-01-01

    Bacterial endocarditis (BE) is a disease resulting from the association of morphological alterations of the heart and bacteraemia originating from different sources that at times can be indiscernible (infectious endocarditis). It is classified on the basis of the morphological alteration involved, depending on the clinical manifestations and course of illness, which varies according to the causative microorganism and host conditions (for example, it is characteristic in I.V. drug users). The most common microorganisms involved are: Streptococcus viridans (55%), Staphylococcus aureus (30%), Enterococcus (6%) and HACEK bacteria (corresponding to the initials: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella and Kingella), although on occasions it can also be caused by fungi. The oral microbiological flora plays a very important role in the aetiopathogenesis of BE, given that the condition may be of oral or dental origin. This paper will deal with the prevention of said bacteraemia. Prophylaxis will be undertaken using amoxicillin or clindamycin according to action protocols, with special emphasis placed on oral hygiene in patients with structural defects of the heart.

  2. 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

  3. Bacterial Communities: Interactions to Scale

    Directory of Open Access Journals (Sweden)

    Reed M. Stubbendieck

    2016-08-01

    Full Text Available 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.

  4. Bacterial Chromosome Organization and Segregation

    OpenAIRE

    Toro, Esteban; Shapiro, Lucy

    2010-01-01

    Bacterial chromosomes are generally ∼1000 times longer than the cells in which they reside, and concurrent replication, segregation, and transcription/translation of this crowded mass of DNA poses a challenging organizational problem. Recent advances in cell-imaging technology with subdiffraction resolution have revealed that the bacterial nucleoid is reliably oriented and highly organized within the cell. Such organization is transmitted from one generation to the next by progressive segrega...

  5. Bacterial Protein-Tyrosine Kinases

    DEFF Research Database (Denmark)

    Shi, Lei; Kobir, Ahasanul; Jers, Carsten

    2010-01-01

    phosphorylation. Protein-tyrosine phosphorylation in bacteria is particular with respect to very low occupancy of phosphorylation sites in vivo; this has represented a major challenge for detection techniques. Only the recent breakthroughs in gel-free high resolution mass spectrometry allowed the systematic...... and highlighted their importance in bacterial physiology. Having no orthologues in Eukarya, BY-kinases are receiving a growing attention from the biomedical field, since they represent a particularly promising target for anti-bacterial drug design....

  6. Surface micropattern limits bacterial contamination

    OpenAIRE

    Mann, Ethan E.; Manna, Dipankar; Mettetal, Michael R; May, Rhea M.; Dannemiller, Elisa M; Chung, Kenneth K.; Brennan, Anthony B; Reddy, Shravanthi T

    2014-01-01

    Background Bacterial surface contamination contributes to transmission of nosocomial infections. Chemical cleansers used to control surface contamination are often toxic and incorrectly implemented. Additional non-toxic strategies should be combined with regular cleanings to mitigate risks of human error and further decrease rates of nosocomial infections. The Sharklet micropattern (MP), inspired by shark skin, is an effective tool for reducing bacterial load on surfaces without toxic additiv...

  7. 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)

  8. 向日葵黄萎病拮抗细菌Y1-2菌株的鉴定与抑制效果%IDENTIFICATION AND INHIBITION EFFECT OF VERTICILLIUM WILT OF SUNFLOWER ANTAGONISM BACTERIA STRAIN Y1 -2

    Institute of Scientific and Technical Information of China (English)

    王颖; 周臣; 张一名; 赵君; 周洪友

    2011-01-01

    从向日葵黄萎病病区的健康植株根际分离到l株对向日葵黄萎病病原菌(Verticillium dahliae Kleb.)具有较强拮抗作用的菌株Y1-2.经形态观察、生理生化测定及16S rDNA序列对比分析结果表明,菌株Y1-2鉴定为Bacillus subtilis,其与(CJT14XVY01S)B.subtilis序列相似性达99.96%.菌株Y1 -2与大丽轮枝菌对峙培养可以形成4 mm的抑菌带,室内防治试验表明Y1 -2菌株对向日葵黄萎病的防治效果为75.3%;在田间小区防治试验中,Y1-2菌株对向日葵黄萎病的防治效果为81.8%.%We isolated the Verticillium wilt of sunflower pathogen( Verticillium dahliae Kleb. ) antagonist bacterial stain Yl -2 from the soil of sunflower roots. The identification results via morphology, physiological and biochemical characters and 16S rDNA analysis suggested that Yl -2 has 99.96% similarity with (CJT14XVY01S) B. Subtilis. The mutual confrontation training of stain Yl -2 and Verticillium dahliae Kleb. Results showed the width of the inhibition belt is 4 mm. The greenhouse control effect of Yl -2 is 75. 3% , and the field control effect reaches to 81. 8 %.

  9. Effects of Additives and Wilt on Crownvetch Silage%添加剂及晾晒对多变小冠花青贮影响的研究

    Institute of Scientific and Technical Information of China (English)

    李清宏; 高文俊; 王永新; 许庆方; 玉柱; 白春生; 张峰

    2012-01-01

    Effects of moisture content and additives of formic acid or sucrose on crownvetch silage were studied in order to make acceptable silage. Fresh or wilted crownvetch during early flowering stage were ensilaged for 360 d. Each group was treated with sucrose (2%) , or formic acid (6 mL ? Kg-1) before ensiling, respectively. Results showed that the pH of wilted crownvetch silage were significantly higher than that of fresh one (P<0. 01). Both lactic acid and ammonia nitrogen content of wilted crownvetch silage were significantly decreased (P<0. 01). The silage fermentation quality was improved with additions of formic acid or sucrose which reduced pH and ammonia contents and increased lactic acid contents of silage significantly (P<0. 01). Crude protein (CP) contents, neutral detergent fiber (NDF), acid detergent fiber (ADF), ash, ethanol extracts (EE) and dry matter recovery of crownvetch silage did not have significant difference among different treatments. Nitrate and 3-nitropropionic acid contents were reduced with ensilaging. Although nitrite content was increased by ensilaging, the total nitrite content was a little.%为获得品质优良的多变小冠花(Coronilla varia L.)青贮饲料,在鲜贮和晾晒条件下分别设置对照(不使用任何添加剂)、添加甲酸(6 mL·kg-1)、添加蔗糖(2%)3种处理,袋装青贮发酵360 d,探究含水量及添加剂(甲酸、蔗糖)对多变小冠花青贮饲料品质的影响.结果表明:与鲜贮相比,晾晒处理下多变小冠花青贮饲料pH值极显著增加(P<0.01),乳酸和氨态氮含量极显著下降(P<0.01).添加甲酸和蔗糖的多变小冠花青贮饲料发酵品质得到改善,pH和氨态氮含量极显著下降(P<0.01),乳酸含量极显著增加(P<0.01).晾晒或添加剂处理对多变小冠花青贮饲料的粗蛋白(crude protein,CP)、中性洗涤纤维(neutral detergent fiber,NDF)、酸性洗涤纤维(acid detergent fiber,ADF)、粗灰分(Ash)、粗脂肪(ethanol extract,EE)的

  10. Isolation and Identification of Antagonistic Bacteria against Fusarium Wilt Tomato%番茄枯萎病菌拮抗菌的分离与初步鉴定

    Institute of Scientific and Technical Information of China (English)

    詹发强; 侯新强; 杨文琦; 杨蓉; 侯敏; 张慧涛; 龙宣杞; 崔卫东

    2011-01-01

    [ Objective ] Fusarium wilt is one of the main diseases of tomato with its occurrence increasingly serious in recent years and causes severe damage to yield and quality of tomato. [ Method ] Methods, such as plate screening, phylogenetic analysis of 16S rRNA, flat confrontation culture and fermented broth antagonistic experiments were used. [ Result ] 64 strains of bacteria have been isolated from the soil planted tomato continuously for many years in Xinjiang, 7 isolates showed certain antagonism against Fusarium wilt pathogen {Fusarium oxysporum (Schl) f. Sp lycopersici) in the preliminary test, and the isolates B -5 and LYT - 5 could inhibit F. Oxysporum significantly in revaluation, which were identified respectively as similar species of Bacillus amyloliquefaciens and Bacillus velezensis by phylogenetic analysis of 16S rRNA. Confrontation test showed that B - 5 and LYT - 5 inhibited the growth of F. Oxysporum with a wide inhibiting zone. Fermented broth antagonistic experiments showed that B - 5 and LYT - 5 could resist F. Oxysporum obviously with its inhibition rate of 100% for 5 days and 98% for another for 5 days. [ Conclusion]The result shows that the two isolates with significant antagonistic effect to F. Oxysporum could provide potential solution for biological control of Fusarium wilt of tomato.%[目的]番茄枯萎病是番茄的主要病害之一,近年来发生尤为严重,严重影响番茄的产量与品质.筛选拮抗菌,为生物防治番茄枯萎病原菌提供新的选择.[方法]采用平板分离培养、16S rRNA系统发育分析、平板对峙培养实验、发酵液拮抗实验等方法.[结果]从新疆多年种植番茄的土壤中分离出64株细菌,初筛有7株细菌具有一定的拮抗作用,复筛得到2株对番茄枯萎病菌(Fusarium oxysporum( Sch1)f.sp lycopersici)具有显著抑制作用的拮抗菌B-5、LYT -5,初步鉴定为Bacillus amyloliquefaciens和Bacillus velezensis的近似种;对峙实验结果表明:B -5

  11. Characterization of in situ nitrogen and fiber digestion and bacterial nitrogen contamination of hay crop forages preserved at different dry matter percentages.

    Science.gov (United States)

    Nocek, J E; Grant, A L

    1987-02-01

    Alfalfa, red clover, orchardgrass and timothy were harvested in the vegetative stage, wilted and stored as hay, or ensiled in small batch silos (20 kg) at 60, 40 or 20% (direct cut) dry matter and were analyzed for compositional differences. A ruminally cannulated lactating cow, consuming 50% of her dry matter intake from hay crop silage, was used to measure in situ dry matter, N, neutral detergent fiber and acid detergent fiber disappearance. Diaminopimelic acid was used as a bacterial marker to correct for bacterial N contamination for in situ residual N. Fibrous components tended to become concentrated as percent dry matter at preservation decreased, presumably associated with leaching of water solubles during storage. For most forages, as dry matter percentage of preservation decreased, water soluble dry matter and N increased, with a concomitant increase of ruminally nondigested dry matter. Specific trends in coefficients of digestion associated with forage type or preservation dry matter percentage were not observed for dry matter, N, neutral detergent fiber or acid detergent fiber. Correction for contamination by bacterial N decreased lag time in digestion and altered rates of N digestion compared with noncorrected rates. Linear and quadratic bacterial N contamination profiles were observed with time of ruminal incubation. Rate of digestion of N was highly correlated with fibrous component concentration, and to a lesser extent to rate of neutral and acid detergent fiber digestion. Dry matter percentage at preservation had a variable effect on ruminal digestion rate of dry matter and N, which varied with forage type and had no effect on neutral detergent and acid detergent fiber digestion rates. Correction for bacterial N contamination should be considered when establishing N digestion rates for forage by the in situ technique.

  12. 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

  13. 黄栌枯萎病菌拮抗细菌的分离与鉴定%Isolation and identification of an antagonistic bacterium against smoke tree wilt fungus Verticillium dahliae

    Institute of Scientific and Technical Information of China (English)

    孙妍; 于地美; 黄华毅; 王永林; 田呈明

    2015-01-01

    为了获得能有效拮抗黄栌枯萎病的大丽轮枝菌( Verticillium dahliae)和尖孢镰刀菌( Fusarium oxysporum)的生防菌株,采用系列稀释分离法和平板对峙法从盐碱地土壤中筛选拮抗细菌,基于形态特征、生理生化特性和16S rDNA序列分析鉴定菌株,并测定其无菌滤液和挥发性气体的抑菌活性。筛选结果表明,菌株C-2-3-2是一株能有效抑制黄栌枯萎病菌和尖孢镰刀菌的生防菌株,经鉴定其为枯草芽孢杆菌( Bacillus subtilis)。该菌株的无菌滤液对黄栌枯萎病菌和尖孢镰刀菌均具有明显的体外抑菌作用,且能有效抑制黄栌枯萎病菌微菌核的形成。同时,其挥发性气体也能有效抑制黄栌枯萎病菌的生长。另外,研究还发现该菌株能产生铁载体和合成氨,并产生几丁质酶、纤维素酶、蛋白酶和β-1,3-葡聚糖酶。研究结果表明菌株C-2-3-2在黄栌枯萎病生物防治中具有较好的应用潜力和较高的研究价值。%In order to isolate and characterize an antagonistic bacterial strain against Verticillium dahliae and Fusarium oxysporum, serial dilution and plate⁃confrontation methods were used for preliminary screening and selecting antagonistic bacteria from saline⁃alkali soil. Strain identification was based on morphological and physiological characteristics, and phylogenetic analysis of 16S rDNA sequence. The antagonistic effects of sterile culture filtrates and volatiles of antagonis⁃tic bacteria were determined. An antagonistic bacteria, named as C-2-3-2, was isolated and identified as Bacillus sub⁃tilis. The results indicated that sterile culture filtrate of the strain exhibited obvious in vitro inhibition against V. dahliae and F. oxysporum, and suppressed the production of microsclerotia of V. dahliae. The volatiles also effectively inhibited the mycelial growth of V. dahliae. In addition, the results indicated that C-2

  14. The Human Vaginal Bacterial Biota and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Sujatha Srinivasan

    2008-01-01

    Full Text Available 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.

  15. Effect of Soil Texture on the Wilting Moisture and the Growth of Crop Seedlings%不同土壤质地对作物凋萎湿度及苗期生长的影响

    Institute of Scientific and Technical Information of China (English)

    田皓; 张红燕; 徐向明; 王涵; 杨文刚; 高金梅

    2012-01-01

    通过对湖北省20个农业气象观测站的处于不同海拔高度、不同土壤质地作物凋萎湿度及苗期生长状况的测定分析.结果表明,不同土壤质地的影响最大,沙土蓄水能力小,保肥能力差,作物只发小苗不发老苗,凋萎速度快;黏土通气性不良,透水性差,保水保肥力较强,作物不发小苗发老苗,虽长势较差,但凋萎速度缓慢;壤土通气透水性良好,保水保肥性较强,作物既发小苗又发老苗,凋萎速度适中.利用气象部门土壤水分监测网,掌握其变化规律,结合天气预报为农民提供实时墒情服务具有重要意义.%The effect of soil texture and different altitude on the wilting moisture and the growth of crop seedlings were analyzed in 20 agrometeorological stations of Hubei province. The results showed that soil texture was the greatest influencing factor on the wilting moisture. The wilting velocity of crop seedlings was the fastest and the water and fertilizer conservation capacity was the worst in sand soil. The aeration and permeability were the poorest in clay soil, the water and fertilizer conservation capacity was strong, thus, the growth of older seedlings was better than that of younger seedlings and the wilting velocity was slowest in this soil. Because of better ventilation and permeability, the growth of younger and older seedlings in loamy soil was better than that in other soil, and the wilting velocity was medium in this soil. It was important that providing real time moisture service based on the monitoring results of soil moisture and weather forecast.

  16. 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.

  17. Bacterial carbonatogenesis; La carbonatogenese bacterienne

    Energy Technology Data Exchange (ETDEWEB)

    Castanier, S. [Angers Univ., 49 (France). Faculte des Sciences; Le Metayer-Levrel, G.; Perthuisot, J.P. [Nantes Univ., 44 (France). Laboratoire de Biogeologie, Faculte des Sciences et des Techniques

    1998-12-31

    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) 43 refs.

  18. 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

    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 on the growers' behavior of control of banana fusarium wilt. Another result of this article indicates that banana plantation's soil PH, organic matter content and the selection of stress-resistant varieties also have some influence on the spread of fusarium wilt. In addition, some measures are proposed accordingly, such as restoring the soil, emphasizing the application of organic fertilizer, focusing on the balance of soil PH etc., these production techniques can guid and normalize growers' behavior. What's more, expanding growers' cognitive depth on the control technology, combining technological supply with its demand, strengthening government's support efforts, establishing a perfect system of integrated prevention and control, which can also achieve the purpose of inhibiting banana fusarium wilt effectively.%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

  19. 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.

  20. Evaluation of Streptomyces sp. strain g10 for suppression of Fusarium wilt and rhizosphere colonization in pot-grown banana plantlets.

    Science.gov (United States)

    Getha, K; Vikineswary, S; Wong, W H; Seki, T; Ward, A; Goodfellow, M

    2005-01-01

    Streptomyces sp. strain g10 exhibited strong antagonism towards Fusarium oxysporum f.sp. cubense (Foc) races 1, 2 and 4 in plate assays by producing extracellular antifungal metabolites. Treating the planting hole and roots of 4-week-old tissue-culture-derived 'Novaria' banana plantlets with strain g10 suspension (10(8) cfu/ml), significantly (P < 0.05) reduced wilt severity when the plantlets were inoculated with 10(4) spores/ml Foc race 4. The final disease severity index for leaf symptom (LSI) and rhizome discoloration (RDI) was reduced about 47 and 53%, respectively, in strain g10-treated plantlets compared to untreated plantlets. Reduction in disease incidence was not significant (P < 0.05) when plantlets were inoculated with a higher concentration (10(6) spores/ml) of Foc race 4. Rhizosphere population of strain g10 showed significant (P = 0.05) increase of more than 2-fold at the end of the 3rd week compared to the 2nd week after soil amendment with the antagonist. Although the level dropped, the rhizosphere population at the end of the 6th week was still nearly 2-fold higher than the level detected after 2 weeks. In contrast, the root-free population declined significantly (P = 0.05), nearly 4-fold after 6 weeks when compared to the level detected after 2 weeks. Neither growth-inhibiting nor growth-stimulating effects were observed in plantlets grown in strain g10-amended soil.

  1. CCR4-Not Complex Subunit Not2 Plays Critical Roles in Vegetative Growth, Conidiation and Virulence in Watermelon Fusarium Wilt Pathogen Fusarium oxysporum f. sp. niveum

    Science.gov (United States)

    Dai, Yi; Cao, Zhongye; Huang, Lihong; Liu, Shixia; Shen, Zhihui; Wang, Yuyan; Wang, Hui; Zhang, Huijuan; Li, Dayong; Song, Fengming

    2016-01-01

    CCR4-Not complex is a multifunctional regulator that plays important roles in multiple cellular processes in eukaryotes. In the present study, the biological function of FonNot2, a core subunit of the CCR4-Not complex, was explored in Fusarium oxysporum f. sp. niveum (Fon), the causal agent of watermelon wilt disease. FonNot2 was expressed at higher levels in conidia and germinating conidia and during infection in Fon-inoculated watermelon roots than in mycelia. Targeted disruption of FonNot2 resulted in retarded vegetative growth, reduced conidia production, abnormal conidial morphology, and reduced virulence on watermelon. Scanning electron microscopy observation of infection behaviors and qRT-PCR analysis of in planta fungal growth revealed that the ΔFonNot2 mutant was defective in the ability to penetrate watermelon roots and showed reduced fungal biomass in root and stem of the inoculated plants. Phenotypic and biochemical analyses indicated that the ΔFonNot2 mutant displayed hypersensitivity to cell wall perturbing agents (e.g., Congo Red and Calcofluor White) and oxidative stress (e.g., H2O2 and paraquat), decreased fusaric acid content, and reduced reactive oxygen species (ROS) production during spore germination. Our data demonstrate that FonNot2 plays critical roles in regulating vegetable growth, conidiogenesis and conidia morphology, and virulence on watermelon via modulating cell wall integrity, oxidative stress response, ROS production and FA biosynthesis through the regulation of transcription of genes involved in multiple pathways. PMID:27695445

  2. 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.

  3. 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.

  4. In planta and soil quantification of Fusarium oxysporum f. sp. ciceris and evaluation of Fusarium wilt resistance in chickpea with a newly developed quantitative polymerase chain reaction assay.

    Science.gov (United States)

    Jiménez-Fernández, Daniel; Montes-Borrego, Miguel; Jiménez-Díaz, Rafael M; Navas-Cortés, Juan A; Landa, Blanca B

    2011-02-01

    Fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceris can be managed by risk assessment and use of resistant cultivars. A reliable method for the detection and quantification of F. oxysporum f. sp. ciceris in soil and chickpea tissues would contribute much to implementation of those disease management strategies. In this study, we developed a real-time quantitative polymerase chain reaction (q-PCR) protocol that allows quantifying F. oxysporum f. sp. ciceris DNA down to 1 pg in soil, as well as in the plant root and stem. Use of the q-PCR protocol allowed quantifying as low as 45 colony forming units of F. oxysporum f. sp. ciceris per gram of dry soil from a field plot infested with several races of the pathogen. Moreover, the q-PCR protocol clearly differentiated susceptible from resistant chickpea reactions to the pathogen at 15 days after sowing in artificially infested soil, as well as the degree of virulence between two F. oxysporum f. sp. ciceris races. Also, the protocol detected early asymptomatic root infections and distinguished significant differences in the level of resistance of 12 chickpea cultivars that grew in that same field plot infested with several races of the pathogen. Use of this protocol for fast, reliable, and cost-effective quantification of F. oxysporum f. sp. ciceris in asymptomatic chickpea tissues at early stages of the infection process can be of great value for chickpea breeders and for epidemiological studies in growth chambers, greenhouses and field-scale plots.

  5. Molecular evidence for the involvement of a polygalacturonase-inhibiting protein, GhPGIP1, in enhanced resistance to Verticillium and Fusarium wilts in cotton

    Science.gov (United States)

    Liu, Nana; Zhang, Xueyan; Sun, Yun; Wang, Ping; Li, Xiancai; Pei, Yakun; Li, Fuguang; Hou, Yuxia

    2017-01-01

    Polygalacturonase-inhibiting protein (PGIP), belonging to a group of plant defence proteins, specifically inhibits endopolygalacturonases secreted by pathogens. Herein, we showed that purified GhPGIP1 is a functional inhibitor of Verticillium dahliae and Fusarium oxysporum f. sp. vasinfectum, the two fungal pathogens causing cotton wilt. Transcription of GhPGIP1 was increased in cotton upon infection, wounding, and treatment with defence hormone and H2O2. Resistance by GhPGIP1 was examined by its virus-induced gene silencing in cotton and overexpression in Arabidopsis. GhPGIP1-silenced cotton was highly susceptible to the infections. GhPGIP1 overexpression in transgenic Arabidopsis conferred resistance to the infection, accompanied by enhanced expression of pathogenesis-related proteins (PRs), isochorismate synthase 1 (ICS1), enhanced disease susceptibility 1 (EDS1), and phytoalexin-deficient 4 (PAD4) genes. Transmission electron microscopy revealed cell wall alteration and cell disintegration in plants inoculated with polygalacturonase (PGs), implying its role in damaging the cell wall. Docking studies showed that GhPGIP1 interacted strongly with C-terminal of V. dahliae PG1 (VdPG1) beyond the active site but weakly interacted with C-terminal of F. oxysporum f. sp. vasinfectum (FovPG1). These findings will contribute towards the understanding of the roles of PGIPs and in screening potential combat proteins with novel recognition specificities against evolving pathogenic factors for countering pathogen invasion. PMID:28079053

  6. Complete sequence of three different biotypes of tomato spotted wilt virus (wild type, tomato Sw-5 resistance-breaking and pepper Tsw resistance-breaking) from Spain.

    Science.gov (United States)

    Debreczeni, Diana E; López, Carmelo; Aramburu, José; Darós, José Antonio; Soler, Salvador; Galipienso, Luis; Falk, Bryce W; Rubio, Luis

    2015-08-01

    Tomato spotted wilt virus (TSWV) occurs worldwide and causes production losses in many important horticultural crops such as tomato and pepper. Breeding resistant cultivars has been the most successful method so far for TSWV disease control, but only two genes have been found to confer resistance against a wide spectrum of TSWV isolates: Sw-5 in tomato and Tsw in pepper. However, TSWV resistance-breaking isolates have emerged in different countries a few years after using resistant cultivars. In this paper, we report the first complete nucleotide sequences of three Spanish TSWV isolates with different biotypes according to their abilities to overcome resistance: LL-N.05 (wild type, WT), Pujol1TL3 (Sw-5 resistance breaking, SBR) and PVR (Tsw resistance-breaking, TBR). The genome of these TSWV isolates consisted of three segments: L (8913-8914 nt), M (4752-4825 nt) and (S 2924-2961 nt). Variations in nucleotide sequences and genomic RNA lengths among the different virus biotypes are reported here. Phylogenetic analysis of the five TSWV open reading frames showed evidence of reassortment between genomic segments of LL-N.05 and Pujol1TL3, which was supported by analysis with different recombination-detecting algorithms.

  7. 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.

  8. 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.

  9. Effect of antagonistic bacteria and soil disinfectant on soil bacterium community in banana fusarium wilt disease area%施用拮抗菌饼肥发酵液和土壤消毒剂对香蕉枯萎病病区土壤细菌群落的影响

    Institute of Scientific and Technical Information of China (English)

    周登博; 井涛; 谭昕; 陈波; 张锡炎; 高祝芬

    2013-01-01

    [Objective] The objective of the present study is to elucidate the effects of the application of cake fertilizer fermentation fluid with antagonistic bacteria and soil disinfectant chlorine dioxide on the occurrence of banana fusarium wilt disease and soil bacterium community.[Method] Under the field cultivation conditions,the Biolog and T-RFLP method was used to investigate the soil bacterium diversity and community features in different treatments at different periods.[Result] The results show that both cake fertilizer fermentation fluid with antagonistic bacteria and soil disinfectant could reduce disease index of banana fusarium wilt disease significantly,the highest control effect could reach 60.82% with the combined application of these two methods.The result of Biolog eco plate shows that the application of cake fertilizer fermentation fluid with antagonistic bacteria could improve soil microbial AWCD (average well color development) and population uniformity,the use of soil disinfectant significantly reduced the soil microbial population' s abundance and the uniformity.Principal component analysis shows that the soil microbial population using carbon source had an increasing trend throughout the banana growing season,the main carbon sources in the early stage were amino acids,carboxylic acids,amphiphilic compounds and carbohydrates,and the increased main carbon sources in the later stage were carboxylic acids and amphiphilic compounds.Soil bacterial diversity analysis by T-RFLP shows that the treatments of cake fertilizer fermentation fluid with antagonistic bacteria had the highest bacterial TRFs (Terminal restriction fragment)fragments,which resulted from the increase of Flavobacterium,Pseudomona and Lactobacillus population in the soil.[Conclusion]The application of cake fertilizer fermentation fluid with antagonistic bacteria combining soil disinfectant could increase antagonistic microorganisms species,enhance soil microbial diversity,improve soil

  10. 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...

  11. Bacterial Cytotoxins Target Rho GTPases

    Science.gov (United States)

    Schmidt, Gudula; Aktories, Klaus

    1998-06-01

    Low molecular mass GTPases of the Rho family, which are involved in the regulation of the actin cytoskeleton and in various signal transduction processes, are the eukaryotic targets of bacterial protein toxins. The toxins covalently modify Rho proteins by ADP ribosylation, glucosylation, and deamidation, thereby inactivating and activating the GTPases.

  12. 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...

  13. Bacterial canker resistance in tomato

    NARCIS (Netherlands)

    Sen, Y.

    2014-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is the pathogen causing bacterial  canker in tomato. The disease was described for the first time in 1910 in Michigan, USA. Cmmis considered the most harmful bacteria threatening tomato. Disease transmission occurs via seed and symptoms becom

  14. 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.

  15. Food irradiation and bacterial toxins

    Energy Technology Data Exchange (ETDEWEB)

    Tranter, H.S.; Modi, N.K.; Hambleton, P.; Melling, J.; Rose, S.; Stringer, M.F.

    1987-07-04

    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.

  16. Extracardiac manifestations of bacterial endocarditis.

    Science.gov (United States)

    Heffner, J E

    1979-08-01

    Bacterial endocarditis is an elusive disease that challenges clinicians' diagnostic capabilities. Because it can present with various combinations of extravalvular signs and symptoms, the underlying primary disease can go unnoticed.A review of the various extracardiac manifestations of bacterial endocarditis suggests three main patterns by which the valvular infection can be obscured. (1) A major clinical event may be so dramatic that subtle evidence of endocarditis is overlooked. The rupture of a mycotic aneurysm may simulate a subarachnoid hemorrhage from a congenital aneurysm. (2) The symptoms of bacterial endocarditis may be constitutional complaints easily attributable to a routine, trivial illness. Symptoms of low-grade fever, myalgias, back pain and anorexia may mimic a viral syndrome. (3) Endocarditis poses a difficult diagnostic dilemma when it generates constellations of findings that are classic for other disorders. Complaints of arthritis and arthralgias accompanied by hematuria and antinuclear antibody may suggest systemic lupus erythematosus; a renal biopsy study showing diffuse proliferative glomerulonephritis may support this diagnosis. The combination of fever, petechiae, altered mental status, thrombocytopenia, azotemia and anemia may promote the diagnosis of thrombotic thrombocytopenic purpura. When the protean guises of bacterial endocarditis create these clinical difficulties, errors in diagnosis occur and appropriate therapy is delayed. Keen awareness of the varied disease presentations will improve success in managing endocarditis by fostering rapid diagnosis and prompt therapy.

  17. Control of Wilt and Rot Pathogens of Tomato by Antagonistic Pink Pigmented Facultative Methylotrophic Delftia lacustris and Bacillus spp.

    Science.gov (United States)

    Janahiraman, Veeranan; Anandham, Rangasamy; Kwon, Soon W.; Sundaram, Subbiah; Karthik Pandi, Veeranan; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Samaddar, Sandipan; Sa, Tongmin

    2016-01-01

    The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM) bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1, and PPB-1, respectively, identified as Delftia lacustris, Bacillus subtilis, and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1, and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05, and 1.95 cm), Sclerotium rolfsii (2.14, 2.04, and 1.94 cm), Pythium ultimum (2.12, 2.02, and 1.92 cm), and Rhizoctonia solani (2.18, 2.08, and 1.98 cm) and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D. lacustris PPO-1, B. subtilis PPT-1, and B. cereus PPB-1 inoculated tomato plants, when challenged with F. oxysporum f. sp. lycopersici, S. rolfsii, P. ultimum, and R. solani, increased the pathogenesis related proteins (β-1,3-glucanase and chitinase) and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase) on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented D. lacustris, B. subtilis, and B. cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent. PMID:27872630

  18. Control of wilt and rot pathogens of tomato by antagonistic pink pigmented facultative methylotrophic Delftia lacustris and Bacillus spp.

    Directory of Open Access Journals (Sweden)

    Veeranan Janahiraman

    2016-11-01

    Full Text Available The studies on the biocontrol potential of pink pigmented facultative methylotrophic (PPFM bacteria other than the genus Methylobacterium are scarce. In the present study, we report three facultative methylotrophic isolates; PPO-1, PPT-1 and PPB-1, respectively identified as Delftia lacustris, Bacillus subtilis and Bacillus cereus by 16S rRNA gene sequence analysis. Hemolytic activity was tested to investigate the potential pathogenicity of isolates to plants and humans, the results indicates that the isolates PPO-1, PPT-1 and PPB-1 are not pathogenic strains. Under in vitro conditions, D. lacustris PPO-1, B. subtilis PPT-1 and B. cereus PPB-1 showed direct antagonistic effect by inhibiting the mycelial growth of fungal pathogens; Fusarium oxysporum f. sp. lycopersici (2.15, 2.05 and 1.95 cm, Sclerotium rolfsii (2.14, 2.04 and1.94 cm, Pythium ultimum (2.12, 2.02 and 1.92cm, and Rhizoctonia solani (2.18, 2.08 and 1.98 cm and also produced volatile inhibitory compounds. Under plant growth chamber condition methylotrophic bacterial isolates; D. lacustris PPO-1, B. subtilis PPT-1 and B. cereus PPB-1 significantly reduced the disease incidence of tomato. Under greenhouse condition, D. lacustris PPO-1, B. subtilis PPT-1 and B. cereus PPB-1 inoculated tomato plants, when challenged with F. oxysporum f. sp. lycopersici, S. rolfsii, P. ultimum and R. solani, increased the pathogenesis related proteins (β-1, 3-glucanase and chitinase and defense enzymes (phenylalanine ammonia lyase, peroxidase, polyphenol oxidase, and catalase on day 5 after inoculation. In the current study, we first report the facultative methylotrophy in pink pigmented Delftia lacustris, B. subtilis, and B. cereus and their antagonistic potential against fungal pathogens. Direct antagonistic and ISR effects of these isolates against fungal pathogens of tomato evidenced their possible use as a biocontrol agent.

  19. Prostatitis-bacterial - self-care

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000395.htm Prostatitis- bacterial - self-care To use the sharing features ... enable JavaScript. You have been diagnosed with bacterial prostatitis . This is an infection of the prostate gland. ...

  20. 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

  1. The bacterial lux reporter system: applications in bacterial localisation studies.

    Science.gov (United States)

    Gahan, Cormac G M

    2012-02-01

    Bacterial production of visible light is a natural phenomenon occurring in marine (Vibrio and Photobacterium) and terrestrial (Photorhabdus) species. The mechanism underpinning light production in these organisms is similar and involves the oxidation of an aldehyde substrate in a reaction catalysed by the bacterial luciferase enzyme. The genes encoding the luciferase and a fatty acid reductase complex which synthesizes the substrate are contained in a single operon (the lux operon). This provides a useful reporter system as cloning the operon into a recipient host bacterium will generate visible light without the requirement to add exogenous substrate. The light can be detected in vivo in the living animal using a sensitive detection system and is therefore ideally suited to bioluminescence imaging protocols. The system has therefore been widely used to track bacteria during infection or colonisation of the host. As bacteria are currently being examined as bactofection vectors for gene delivery, particularly to tumour tissue, the use of bioluminescence imaging offers a powerful means to investigate vector amplification in situ. The implications of this technology for bacterial localization, tumour targeting and gene transfer (bactofection) studies are discussed.

  2. Distribution of Triplet Separators in Bacterial Genomes

    Institute of Scientific and Technical Information of China (English)

    HU Rui; ZHENG Wei-Mou

    2001-01-01

    Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets.``

  3. Produção de silagem de capim-marandu (Brachiaria brizantha Stapf cv. Marandu com e sem emurchecimento Production of marandu grass (Brachiaria brizantha Stapf cv. Marandu Silage with and without wilting

    Directory of Open Access Journals (Sweden)

    Antônio Ricardo Evangelista

    2004-04-01

    Full Text Available Este experimento foi conduzido com o objetivo de avaliar algumas características da silagem de capim-marandu (Brachiaria brizantha Stapf cv. Marandu submetida a diferentes tempos de emurchecimento. O delineamento experimental usado foi o inteiramente casualizado com quatro tratamentos e quatro repetições. Os tratamentos foram tempos de emurchecimento de zero, duas, quatro e seis horas após o corte, em pleno sol. A gramínea foi colhida com aproximadamente 90 dias de rebrota e permaneceu ensilada por 40 dias em silos experimentais de canos de PVC. Determinaram-se os valores de pH, poder tampão (PT e os teores de MS, PB, FDN, FDA e nitrogênio amoniacal (N-NH3. Pelas características analisadas, pôde-se concluir que o capim-marandu ensilado após emurchecimento de 1,32 a 3,02 horas pode ser satisfatoriamente armazenado na forma de silagem, conciliando vantagens operacionais e de qualidade da forragem.The experiment was conducted with the objective to evaluate some characteristics of the silage of marandu grass (Brachiaria brizantha Stapf cv. Marandu submitted to different wilting times. The completely randomized design with four treatments and four replicates was used. The treatments were wilting time of zero, two, four and six hours after the cut, in broad sunligth. The grass was harvested after 90 days of sprouting and stored for 40 days in experimental silos of PVC tube. pH values, buffer power (BC and contents of DM, CP, NDF, ADF and ammonium nitrogen (N-NH3 were determined. The analyzed characteristics allowed to conclude that marandu grass stored after wilting of 1,32 at 3,02 hours, could be preserved satisfactorily in the form of silage, conciliating operationals advantages and forage quality.

  4. 松材线虫危害后马尾松林土壤氮素的矿化特性%Soil Nitrogen Mineralization in Pinus massoniana Stands After Disturbance by Pine Wilt Disease

    Institute of Scientific and Technical Information of China (English)

    王蕾蕾; 尹维彬; 岳妍; 徐小牛

    2012-01-01

    选择合肥大蜀山森林公园受松材线虫危害程度不同的马尾松林为研究对象,采用室内模拟试验对林地土壤氮素矿化特征进行了研究.结果表明:不同林分土壤氮素转化速率差异显著(P<0.05),受损严重的林分氮素矿化速率显著高于轻度受损林分,特别是硝化速率更为显著(P<0.01).松材线虫病危害改变了马尾松林土壤氮素的转化性质,增加了土壤氮素淋失的危险性.%Masson pine stands after different degrees of damage by pine wilt disease in Shushan Forest Park were selected to investigate the changes in soil nitrogen mineralization using the laboratory incubation method. Result showed that a significant change in nitrogen mineralization occurred in the pine stands after disturbance by pine wilt disease (at the 0.05 level). The stands seriously damaged exhibited a significantly higher rate of nitrogen mineralization, especially nitrification, compared with the stands slightly damaged. The disturbance by pine wilt disease resulted in a significant change in soil nitrogen mineralization, with an obvious increase in nitrification rate (at the 0.01 level), which suggests a high potential for nitrogen leaching in the damaged stands.

  5. Características fermentativas de silagens de capim-elefante emurchecido ou com adição de farelo de cacau Fermentation characteristics of silage of elephantgrass wilted or with addition of cocoa meal

    Directory of Open Access Journals (Sweden)

    G.G.P. Carvalho

    2008-02-01

    Full Text Available O experimento foi realizado para avaliar as características fermentativas da silagem de capim-elefante emurchecido ou adicionado 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 na ensilagem: capim-elefante emurchecido ao sol por oito horas e capim-elefante sem emurchecimento adicionado de 0, 7, 14, 21 e 28% de farelo de cacau (% da matéria natural. Foram utilizadas quatro repetições por tratamento. O material foi acondicionado em silos de PVC com 0,15m de diâmetro e 0,3m de altura, adotando-se compactação de 500kg/m³. O pH reduziu e os carboidratos solúveis (CHO S aumentaram de forma linear (PThe experiment was carried out to evaluate the fermentation characteristics of eight hours sun light wilted elephant grass silage in comparison to no sun light exposed silage added by 0, 7, 14, 21, and 28% of cocoa meal during the ensilage process. PVC silos, measuring 0.15m diameter x 0.30m height, were used to ensilage the elephantgrass using a compacting pressure of 500kg/m³. Soluble carbohydrates decreased but pH and N-NH3 increased (P<0.05 as the cocoa meal level increased in the silage. No difference between wilted and no wilted elephantgrass silages was observed for organic acid content. Addition of 0, 7, 14, 21, and 28% of cocoa meal caused an increase of 2.23, 2.48, 3.14, 3.49, and 3.87% of lactic acid contents. Addition of cocoa meal during the ensilage process enhanced fermentation quality of elephantgrass silage.

  6. 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.

  7. 抗松材线虫赤松组培繁殖优良家系的筛选%Selection of wilt-resistant Pinus densiflora superior families for tissue culture propagation

    Institute of Scientific and Technical Information of China (English)

    李清清; 叶建仁; 吴小芹

    2013-01-01

    Using the embryo seedlings with cotyledons of 27 wilt-resistant Pinus densiflora families as explants, superior families which were good growth vigor, high multiplication rate and strong rooting ability were selected. The average e-longation percentages of No. 1, 8, 10, 13, 22 and 25 families were up to above 100% ; With the increase of proliferation generations, the multiplication coefficient of clustered shoots in each family was variable, but the overall trend was that multiplication coefficient of clustered shoots from generation 1 to generation 2 increased with generation increase, and multiplication coefficient from generation 2 to generation 3 decreased; Adventitious root induction rate of wilt-resistant P. densiflora clones was different, 19-B clone of wilt-resistant P. densiflora was the highest,up to 95. 8% .%以抗松材线虫赤松(简称抗病赤松)27个家系带子叶顶芽的胚苗为外植体,筛选生长势好、增殖系数高和生根能力强的组培繁殖优良家系.结果表明:1、8、10、13、22和25家系的平均伸长率都达到了100%以上;随着增殖代数的增加,各家系丛生芽增殖系数表现不一致,但总体趋势是l至2代丛生芽增殖系数随代数增加而增加,2至3代增殖系数随代数增加而下降;抗病赤松不同无性系不定根诱导率不同,19-B无性系的不定根诱导率最高为95.8%.

  8. The Impact of Genotyping-by-Sequencing Pipelines on SNP Discovery and Identification of Markers Associated with Verticillium Wilt Resistance in Autotetraploid Alfalfa (Medicago sativa L.)

    Science.gov (United States)

    Yu, Long-Xi; Zheng, Ping; Bhamidimarri, Suresh; Liu, Xiang-Ping; Main, Dorie

    2017-01-01

    Verticillium wilt (VW) of alfalfa is a soilborne disease causing severe yield loss in alfalfa. To identify molecular markers associated with VW resistance, we used an integrated framework of genome-wide association study (GWAS) with high-throughput genotyping by sequencing (GBS) to identify loci associated with VW resistance in an F1 full-sib alfalfa population. Phenotyping was performed using manual inoculation of the pathogen to cloned plants of each individual and disease severity was scored using a standard scale. Genotyping was done by GBS, followed by genotype calling using three bioinformatics pipelines including the TASSEL-GBS pipeline (TASSEL), the Universal Network Enabled Analysis Kit (UNEAK), and the haplotype-based FreeBayes pipeline (FreeBayes). The resulting numbers of SNPs, marker density, minor allele frequency (MAF) and heterozygosity were compared among the pipelines. The TASSEL pipeline generated more markers with the highest density and MAF, whereas the highest heterozygosity was obtained by the UNEAK pipeline. The FreeBayes pipeline generated tetraploid genotypes, with the least number of markers. SNP markers generated from each pipeline were used independently for marker-trait association. Markers significantly associated with VW resistance identified by each pipeline were compared. Similar marker loci were found on chromosomes 5, 6, and 7, whereas different loci on chromosome 1, 2, 3, and 4 were identified by different pipelines. Most significant markers were located on chromosome 6 and they were identified by all three pipelines. Of those identified, several loci were linked to known genes whose functions are involved in the plants’ resistance to pathogens. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms of VW resistance in alfalfa. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance

  9. Role of insecticides in reducing thrips injury to plants and incidence of tomato spotted wilt virus in Virginia market-type peanut.

    Science.gov (United States)

    Herbert, D Ames; Malone, S; Aref, S; Brandenburg, R L; Jordan, D L; Royals, B M; Johnson, P D

    2007-08-01

    Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV), transmitted by many thrips species, is a devastating pathogen of peanut, Arachis hypogaea L. TSWV has become a serious problem in the Virginia/Carolina peanut-growing region of the United States. During 2002, TSWV was present in 47% of the North Carolina hectarage and caused a 5% yield reduction in Virginia. Factors influencing levels of TSWV in runner market-type peanut cultivars, which are primarily grown in Alabama, Flordia, Georgia, and Texas, have been integrated into an advisory to help those peanut growers reduce losses. An advisory based on the southeast runner market-type version is currently under development for virginia market-type peanut cultivars that are grown primarily in the Virginia/ Carolina region. A version based on preliminary field experiments was released in 2003. One factor used in both advisories relates to insecticide use to reduce the vector populations and disease incidence. This research elucidated the influence of insecticides on thrips populations, thrips plant injury, incidence of TSWV, and pod yield in virginia market-type peanut. Eight field trials from 2003 to 2005 were conducted at two locations. In-furrow application of aldicarb and phorate resulted in significant levels of thrips control, significant reductions in thrips injury to seedlings, reduced incidence of TSWV, and significant increases in pod yield. Foliar application of acephate after aldicarb or phorate applied in the seed furrow further reduced thrips plant injury and incidence of TSWV and improved yield. These findings will be used to improve the current virginia market-type TSWV advisory.

  10. Identification of a new antagonistic bacteria HM-7 against the cucumber Fusarium wilt%黄瓜枯萎病拮抗菌HM-7的鉴定

    Institute of Scientific and Technical Information of China (English)

    唐蕊; 张雪辉; 殷世群; 万慧洁

    2016-01-01

    It was studied that the initially identification of the selected antagonistic bacteria HM-7 of cucumber fusarium wilt in order to lay the foundation to the development of biological pesticide. HM-7 was identified according to the cultural characteristics in different medium and its individual form under a microscope,with 16S rDNA complete sequence analysis by comparing the consequences with standard strains and then construct a phylogenetic tree. The results showed that HM-7 was initially identified as Bacillus amyloquefaciens. Bacillus genus is one of microbial groups which were researched exten⁃sively and deeply,and it was one of the main sources of bio-control bacteria which applied in biological control of plant dis⁃ease. So HM-7 is expected to be developed for biological pesticide.%为开发防治黄瓜枯萎病的生物制剂奠定基础,通过对已筛选的黄瓜枯萎病拮抗菌HM-7进行培养特征观察、显微观察、革兰氏染色、16S rDNA全序列分析、系统发育分析等研究,初步鉴定拮抗菌HM-7为解淀粉芽孢杆菌。芽孢杆菌属是研究较为广泛和深入的微生物类群之一,也是植物病害生物防治生防菌的主要来源之一,因此拮抗菌HM-7有望开发为生物制剂应用于农业生产。

  11. Effects of Endobacterium (Stenotrophomonas maltophilia on Pathogenesis-Related Gene Expression of Pine Wood Nematode (Bursaphelenchus xylophilus and Pine Wilt Disease

    Directory of Open Access Journals (Sweden)

    Long-Xi He

    2016-05-01

    Full Text Available Pine wilt disease (PWD caused by the pine wood nematode (PWN, Bursaphelenchus xylophilus, is responsible for devastating epidemics in pine trees in Asia and Europe. Recent studies showed that bacteria carried by the PWN might be involved in PWD. However, the molecular mechanism of the interaction between bacteria and the PWN remained unclear. Now that the whole genome of B. xylophilus (Bursaphelenchus xylophilus is published, transcriptome analysis is a unique method to study the role played by bacteria in PWN. In this study, the transcriptome of aseptic B. xylophilus, B. xylophilus treated with endobacterium (Stenotrophomonas maltophilia NSPmBx03 and fungus B. xylophilus were sequenced. We found that 61 genes were up-regulated and 830 were down-regulated in B. xylophilus after treatment with the endobacterium; 178 genes were up-regulated and 1122 were down-regulated in fungus B. xylophilus compared with aseptic B. xylophilus. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were used to study the significantly changed biological functions and pathways for these differentially expressed genes. Many pathogenesis-related genes, including glutathinone S-transferase, pectate lyase, ATP-binding cassette transporter and cytochrome P450, were up-regulated after B. xylophilus were treated with the endobacterium. In addition, we found that bacteria enhanced the virulence of PWN. These findings indicate that endobacteria might play an important role in the development and virulence of PWN and will improve our understanding of the regulatory mechanisms involved in the interaction between bacteria and the PWN.

  12. Winter weeds as inoculum sources of tomato spotted wilt virus and as reservoirs for its vector, Frankliniella fusca (Thysanoptera: Thripidae) in farmscapes of Georgia.

    Science.gov (United States)

    Srinivasan, Rajagopalbabu; Riley, David; Diffie, Stan; Shrestha, Anita; Culbreath, Albert

    2014-04-01

    Thrips-transmitted Tomato spotted wilt virus (TSWV) has a broad host range including crops and weeds. In Georgia, TSWV is known to consistently affect peanut, tomato, pepper, and tobacco production. These crops are grown from March through November. In the crop-free period, weeds are presumed to serve as a green bridge for thrips and TSWV. Previous studies have identified several winter weeds as TSWV and thrips hosts. However, their ability to influence TSWV transmission in crops is still not completely understood. To further understand these interactions, population dynamics of two prevalent vectors, viz., Frankliniella fusca (Hinds) and Frankliniella occidentalis (Pergande), on selected winter weeds were monitored from October through April in four counties from 2004 to 2008. Peak populations were typically recorded in March. F. fusca and F. occidentalis adults were found on winter weeds and their percentages ranged from 0 to 68% in comparison with other adults. Immatures outnumbered all adults. Microcosm experiments indicated that the selected winter weeds differentially supported F. fusca reproduction and development. The time required to complete one generation (adult to adult) ranged from 11 to 16 d. Adult recovery ranged from 0.97 to 2.2 per female released. In addition, transmission assays revealed that thrips efficiently transmitted TSWV from peanut to weeds, the incidence of infection ranged from 10 to 55%. Back transmission assays with thrips from TSWV-infected weeds resulted in up to 75% TSWV infection in peanut. These whole-plant transmission and back transmission assays provide the basis for TSWV persistence in farmscapes year round.

  13. Activation of salicylic acid metabolism and signal transduction can enhance resistance to Fusarium wilt in banana (Musa acuminata L. AAA group, cv. Cavendish).

    Science.gov (United States)

    Wang, Zhuo; Jia, Caihong; Li, Jingyang; Huang, Suzhen; Xu, Biyu; Jin, Zhiqiang

    2015-01-01

    Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cubens (Foc) is the most serious disease that attacks banana plants. Salicylic acid (SA) can play a key role in plant-microbe interactions. Our study is the first to examine the role of SA in conferring resistance to Foc TR4 in banana (Musa acuminata L. AAA group, cv. Cavendish), which is the greatest commercial importance cultivar in Musa. We used quantitative real-time reverse polymerase chain reaction (qRT-PCR) to analyze the expression profiles of 45 genes related to SA biosynthesis and downstream signaling pathways in a susceptible banana cultivar (cv. Cavendish) and a resistant banana cultivar (cv. Nongke No. 1) inoculated with Foc TR4. The expression of genes involved in SA biosynthesis and downstream signaling pathways was suppressed in a susceptible cultivar and activated in a resistant cultivar. The SA levels in each treatment arm were measured using high-performance liquid chromatography. SA levels were decreased in the susceptible cultivar and increased in the resistant cultivar. Finally, we examined the contribution of exogenous SA to Foc TR4 resistance in susceptible banana plants. The expression of genes involved in SA biosynthesis and signal transduction pathways as well as SA levels were significantly increased. The results suggest that one reason for banana susceptibility to Foc TR4 is that expression of genes involved in SA biosynthesis and SA levels are suppressed and that the induced resistance observed in banana against Foc TR4 might be a case of salicylic acid-dependent systemic acquired resistance.

  14. 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.

  15. 西花蓟马传播番茄斑萎病毒研究进展%Reaearch advances on transmission of tomato spotted wilt virus by Frankliniella occidentalis (Pergande)

    Institute of Scientific and Technical Information of China (English)

    杨帆; 刘万学; 张国; 万方浩

    2011-01-01

    Frankliniella occidentalis is one of the important quarantine pests in the world.This pest not only damages crops, but also transmits virus, thus causing serious economic loss to crops.As the F.occidentalis invaded into China, and the tomato spotted wilt virus it transmitted was found in various regions in China, it seriously threatened the cash crops due to its wide suitable distribution areas.This article summarizes the process that F.occidentalis gets, carries and transmits the tomato spotted wilt virus, and the cycle of the virus in F.occidentalis and the associated mechanism.This article also reviews the F.occidentalis - virus - plant interaction and its effect on the fitness of F.occidentalis, so as to provide a guide to the fundamental research and application in the transmission of tomato spotted wilt virus mediated by F.occidentalis.%西花蓟马Frankliniella occidentalis是世界性重要检疫性害虫之一,不仅直接取食危害作物而且传播病毒,从而造成极为严重的经济损失.由于西花蓟马在我国具有广泛的适生范围,随其入侵我国并随之传播的番茄斑萎病毒(Tomato spotted wilt virus)已在我国不同地域发现,对经济作物已形成严重威胁.本文综述了西花蓟马对番茄斑萎病毒的获取、携带和传播扩散过程及其病毒在蓟马体内的循环过程和机理,总结了影响西花蓟马传播番茄斑萎病毒效率的因素,并评述了"西花蓟马-病毒-植物"这一互作系统及其对西花蓟马生长发育适合度的影响,以期为我国西花蓟马传播番茄斑萎病毒的基础研究和防控提供理论依据与指导.

  16. Antibiotic drugs targeting bacterial RNAs

    Directory of Open Access Journals (Sweden)

    Weiling Hong

    2014-08-01

    Full Text Available RNAs have diverse structures that include bulges and internal loops able to form tertiary contacts or serve as ligand binding sites. The recent increase in structural and functional information related to RNAs has put them in the limelight as a drug target for small molecule therapy. In addition, the recognition of the marked difference between prokaryotic and eukaryotic rRNA has led to the development of antibiotics that specifically target bacterial rRNA, reduce protein translation and thereby inhibit bacterial growth. To facilitate the development of new antibiotics targeting RNA, we here review the literature concerning such antibiotics, mRNA, riboswitch and tRNA and the key methodologies used for their screening.

  17. Electromagnetic Signals from Bacterial DNA

    CERN Document Server

    Widom, A; Srivastava, Y N; Sivasubramanian, S

    2011-01-01

    Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Bacterial Interstitial Nephritis in Children

    OpenAIRE

    Bobadilla Chang, Fernando; Departamento de Ciencias Dinámicas Facultad de Medicina Universidad Nacional Mayor de San Marcos Lima, Perú; Villanueva, Dolores; Departamento de Ciencias Dinámicas Facultad de Medicina Universidad Nacional Mayor de San Marcos Lima, Perú

    2014-01-01

    OBJECTIVE: To assess the diagnosis approach to urinary tract infections in children. MATERIAL AND METHODS: Medical records from 103 children with diagnosis of interstitial bacterial nephritis were retrospectively reviewed. Diagnosis was supported by the dramatic involvement of renal parenquima, which is not addressed as "urinary tract infection". RESULTS: From all 103 patients, 49 were 2-years-old or younger, 33 were between 2 and 5-years-old, and 21 were between 6 to 10. Clinical picture inc...

  5. Bacterial canker resistance in tomato

    OpenAIRE

    Sen, Y.

    2014-01-01

    Clavibacter michiganensis subsp. michiganensis (Cmm) is the pathogen causing bacterial  canker in tomato. The disease was described for the first time in 1910 in Michigan, USA. Cmmis considered the most harmful bacteria threatening tomato. Disease transmission occurs via seed and symptoms become visible at least 20 days after infection. Due to its complex strategy and transmission, Cmm is under quarantine regulation in EU and other countries. There is no method to stop disease progress i...

  6. 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...

  7. 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...

  8. Bacterial motility on abiotic surfaces

    OpenAIRE

    Gibiansky, Maxsim

    2013-01-01

    Bacterial biofilms are structured microbial communities which are widespread both in nature and in clinical settings. When organized into a biofilm, bacteria are extremely resistant to many forms of stress, including a greatly heightened antibiotic resistance. In the early stages of biofilm formation on an abiotic surface, many bacteria make use of their motility to explore the surface, finding areas of high nutrition or other bacteria to form microcolonies. They use motility appendages, incl...

  9. Cytochemical Differences in Bacterial Glycocalyx

    Science.gov (United States)

    Krautgartner, Wolf Dietrich; Vitkov, Ljubomir; Hannig, Matthias; Pelz, Klaus; Stoiber, Walter

    2005-02-01

    To examine new cytochemical aspects of the bacterial adhesion, a strain 41452/01 of the oral commensal Streptococcus sanguis and a wild strain of Staphylococcus aureus were grown with and without sucrose supplementation for 6 days. Osmiumtetraoxyde (OsO4), uranyl acetate (UA), ruthenium red (RR), cupromeronic blue (CB) staining with critical electrolytic concentrations (CECs), and the tannic acid-metal salt technique (TAMST) were applied for electron microscopy. Cytochemically, only RR-positive fimbriae in S. sanguis were visualized. By contrast, some types of fimbriae staining were observed in S. aureus glycocalyx: RR-positive, OsO4-positive, tannophilic and CB-positive with ceasing point at 0.3 M MgCl2. The CB staining with CEC, used for the first time for visualization of glycoproteins of bacterial glycocalyx, also reveals intacellular CB-positive substances-probably the monomeric molecules, that is, subunits forming the fimbriae via extracellular assembly. Thus, glycosylated components of the biofilm matrix can be reliably related to single cells. The visualization of intracellular components by CB with CEC enables clear distinction between S. aureus and other bacteria, which do not produce CB-positive substances. The small quantities of tannophilic substances found in S. aureus makes the use of TAMST for the same purpose difficult. The present work protocol enables, for the first time, a partial cytochemical differentiation of the bacterial glycocalyx.

  10. DIAGNOSTIC DIFFICULTIES IN BACTERIAL SPONDYLODISCITIS

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    Vinicius Orso

    2015-12-01

    Full Text Available Objective : To analyze aspects related to the diagnostic difficulty in patients with bacterial spondylodiscitis. Methods : Cross-sectional observational study with retrospective data collected in the period from March 2004 to January 2014.Twenty-one patients diagnosed with bacterial spondylodiscitis were analyzed. Results : Women were the most affected, as well as older individuals. Pain in the affected region was the initial symptom in 52% of patients, and 45.5% of the patients had low back pain, and those with dorsal discitis had back pain as the main complaint; the patients with thoracolumbar discitis had pain in that region, and only one patient had sacroiliac discitis. The average time between onset of symptoms and treatment was five months. The lumbar segment was the most affected with 11 cases (52%, followed by thoracolumbar in 24%, dorsal in 19% of cases and a case in the sacroiliac segment. Only seven patients had fever. Pain in the affected level was coincidentally the most common symptom. Conclusions : Early diagnosis of bacterial spondylodiscitis remains a challenge due to the nonspecific signs and symptoms reported by the patient and the wide variability of laboratory results and imaging. The basis for early diagnosis remains the clinical suspicion at the time of initial treatment.

  11. Detergent-compatible bacterial amylases.

    Science.gov (United States)

    Niyonzima, Francois N; More, Sunil S

    2014-10-01

    Proteases, lipases, amylases, and cellulases are enzymes used in detergent formulation to improve the detergency. The amylases are specifically supplemented to the detergent to digest starchy stains. Most of the solid and liquid detergents that are currently manufactured contain alkaline enzymes. The advantages of using alkaline enzymes in the detergent formulation are that they aid in removing tough stains and the process is environmentally friendly since they reduce the use of toxic detergent ingredients. Amylases active at low temperature are preferred as the energy consumption gets reduced, and the whole process becomes cost-effective. Most microbial alkaline amylases are used as detergent ingredients. Various reviews report on the production, purification, characterization, and application of amylases in different industry sectors, but there is no specific review on bacterial or fungal alkaline amylases or detergent-compatible amylases. In this mini-review, an overview on the production and property studies of the detergent bacterial amylases is given, and the stability and compatibility of the alkaline bacterial amylases in the presence of the detergents and the detergent components are highlighted.

  12. 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.

  13. Bacterial meningitis and diseases caused by bacterial toxins.

    Science.gov (United States)

    Rings, D M

    1987-03-01

    Bacterial meningitis most commonly occurs in young calves secondary to septicemia. Clinical signs of hyperirritability are usually seen. Meningitis can be confirmed by cerebrospinal fluid analysis and culture or by necropsy. Intoxications by the exotoxins of Clostridium perfringens types C and D, C. botulinum, and C. tetani are difficult to confirm. The clinical signs of these intoxications vary from flaccid paralysis (botulism) to muscular rigidity (tetanus). Treatment of affected cattle has been unrewarding in botulism and enterotoxemia, whereas early aggressive treatment of tetanus cases can often be successfully resolved. Botulism and enterotoxemia can be proved using mouse inoculation tests, whereas tetanus is diagnosed largely by ruling out other diseases.

  14. 胜红蓟青枯病病原鉴定及其生物学特性%Pathogen identification of Ageratum conyzoides bacterial wilt disease and its biological characteristics

    Institute of Scientific and Technical Information of China (English)

    佘小漫; 何自福; 罗方芳

    2013-01-01

    胜红蓟青枯病是我国发生的一种新病害.为了明确引起胜红蓟青枯病的病原,对分离自广东的胜红蓟青枯病菌的菌落形态、16S rDNA序列、碳水化合物利用、致病性及演化型等进行了分析.在含1% 2,3,5-氯化三苯基四氮唑选择性培养基平板上,病原菌的菌落呈近圆形或梭形,隆起,中间粉红色,周围乳白色.应用细菌通用引物27f和1541r扩增16S rDNA,Ac-YcSj-11-1 ~ Ac-YcSj-11-10 10个菌株的16S rDNA近全长均为1421bp,且与茄科雷尔氏菌Ralstonia solanacearum GMI1000 16S rD-NA的同源率为100%.该病原菌可以利用麦芽糖、乳糖、纤维二糖、山梨醇、甘露醇和卫矛醇等6种碳水化合物,并可侵染姜、沙姜、番茄,弱侵染茄子、辣椒.10个菌株均可同时扩增得到144 bp的演化型Ⅰ特异带和280 bp的茄科雷尔氏菌特异带.研究表明,引起广东胜红蓟青枯病的病原菌为茄科雷尔氏菌R.solanacearum,且属于4号生理小种、生化变种Ⅲ和演化型Ⅰ(亚洲组).

  15. 抗青枯病转多肽抗生素基因烟草的选育%The breeding of transgenic tobacco with peptide antibiotic genes against bacterial wilt

    Institute of Scientific and Technical Information of China (English)

    徐进; 冯洁; 顾刚; 陈顺辉; 彭学贤; 孙超

    2008-01-01

    分别于温室和田间条件下,对转单价apidaecin、shiva-Ⅰ及双价apidaecin+shiva-Ⅰ基因的14个烟草株系材料的T1和T2后代群体进行青枯病抗性筛选鉴定及农艺性状评价.温室盆栽试验中,于5~6叶龄期采用伤根法进行接种.接种后15天.转apidaecin、shiva-Ⅰ和apidaecin+shiva-Ⅰ基因烟草的病情指数较对照分别下降了16.3%、15.2%和59.7%.田间自然病圃筛选鉴定结果表明:B43-5-4、B43-5-1、B43-5-2、B43-5-3和B43-4-1等5个株系材料病情指数较起始品种K326降低21%~70%,且农艺性状与起始品种K326无显著差异.

  16. The effect of supplementing highly wilted grass silage with maize silage, fodder beet or molasses on degradation of the diets and the efficiency of microbial protein synthesis in the rumen of sheep

    Directory of Open Access Journals (Sweden)

    Špela Velikonja-Bolta

    2010-11-01

    Full Text Available This study aimed at determining the efficiency of microbial protein synthesis (EMPS in diets based on highly wilted grass silage (GS, 539 g dry matter (DM per kg with the supplementation of starch or water-soluble carbohydrates (WSC rich feeds, i.e. maize silage (MS, 391 g kg-1 DM intake [DMI], fodder beet (FB, 173 g kg-1 DMI or molasses (M, 137 g kg-1 DMI. All the diets were made isonitrogenous by urea supplementation (14.0, 4.0 and 2.0 g per kg DMI in GS-MS, GS-FB and GS-M diets. In sacco determined crude protein (CP and organic matter (OM degradabilities were 756, 800, 778 and 814 (P0.05 among the diets (36.6, 35.1, 34.7 and 34.0 g microbial nitrogen per kg OM apparently digested in the rumen in GS, GS-MS, GS-FB and GS-M diets, respectively. The estimated metabolizable protein supply from GS, GS-MS, GS-FB and GS-M diets amounted to 97, 91, 93 and 86 g kg-1 DMI, respectively. Apparently, highly wilted GS containing a high concentration of WSC (91 g kg-1 DM supports high EMPS in the rumen and this cannot be improved by the supplementation with starch or WSC rich feeds.

  17. 枯草芽孢杆菌植入棉苗体内拮抗黄萎病研究%The Studies of Bacillus Subtilis Implanted in Cotton Breedings to Antagonize Verticillium Wilt

    Institute of Scientific and Technical Information of China (English)

    王谧; 王维东; 范玉刚

    2011-01-01

    在棉花无土育苗基质中植入枯草芽孢杆菌,使其优先占领生态位,而拮抗黄萎病。结果表明:枯草芽孢杆菌CD102菌液稀释后植入灭菌基质,能在短期内增殖和持续繁殖;采用浸种、浇灌、针刺和喷雾的方法处理基质培育的棉苗,CD102均能不同程度定植其中;带CD102的基质培育棉苗,移栽大田后对黄萎病具有较好防治效果。%Bacillus subtilis CD102 was implanted to cotton seedling substrate,It had priority to occupy ecological niche and antagonized the infection of Verticillium Wilt.Results showed that: the bacillus subtilis CD102 was implanted to sterilized substrate and proliferated rapidly and continuously;It was all implanted to cotton seedling raised by substance,which accomplished by all methods including seed-soaking,pouring,acupuncture and spraying.Cotton seedlings raised by substrate with CD102 had good antagonistic effect to Vertillium Wilt after transplanting to field.

  18. Identification and Colonization of Bacteria AFll Antagonistic against Fusarium oxysporum f. sp. cubense Race 4, the Pathogen of Banana Wilt Disease%香蕉枯萎病生防菌AF11的鉴定及其定殖研究

    Institute of Scientific and Technical Information of China (English)

    胡伟; 赵兰凤; 张亮; 杨江舟; 张静; 李华兴

    2012-01-01

    Authors obtained an endophytic bacterial strain AFII from the root of healthy soybean plants. Pot experiments showed that AF11 reduced by 71.5% banana wilt disease caused byFusarium oxysporum f. sp. cubense Race 4 (FOC Race 4) as investigated at 30 days after treatment with pouring root at 106 cfu.mL-1. The strain was identified as Bacillus amyloliquefaciens based on its morphological and physiological properties and its 16S rRNA sequence. A mutant AF 11RJf resistant to Rifampicin at 100 μg-mL-1 was obtained by successive cultures on medium plates amended with increased concentration of Rifampicin. The mutant were stable in antagonism against FOC Race 4, and was used to inoculate banana by pouring root system. Re-isolation indicated that the strain AFllRif could colonize root and stem of banana by 118 cfumg-1 and 32 cfu.mg-1, respectively, at 50 d after inoculation.%从健康大豆根系内分离出一株对香蕉枯萎病病原菌Fusarium oxysporum f.sp.cubense Race 4(FOC Race4)有强拮抗效果的内生细菌AF11。盆栽防病试验结果表明其对香蕉枯萎病的防效达71.5%。形态特征、生理生化测定和16S rDNA序列及其系统发育树分析初步确定该菌株为解淀粉芽孢杆菌Bacillus amyloliquefaciens。从菌株AF11中筛选出抗利福平(100μg.mL-1)且对FOC Race 4拮抗活性稳定的变异菌株AF11Rif,采用灌根接种方法,研究菌株AF11Rif在香蕉体内定殖分布规律。试验结果表明,菌株AF11Rif能定殖于香蕉根部和茎部,接种50 d后根部定殖量为118 cfu.mg-1,茎部为32 cfu.mg-1。

  19. 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.

  20. 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.

  1. Periodontal diseases as bacterial infection

    Directory of Open Access Journals (Sweden)

    A. Bascones Martínez

    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.

  2. 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.

  3. Bacterial pericarditis in a cat

    Directory of Open Access Journals (Sweden)

    Nicole LeBlanc

    2015-09-01

    Full Text Available Case summary A 4-year-old male neutered domestic shorthair cat was presented to the Oregon State University cardiology service for suspected pericardial effusion. Cardiac tamponade was documented and pericardiocentesis yielded purulent fluid with cytologic results supportive of bacterial pericarditis. The microbial population consisted of Pasteurella multocida, Actinomyces canis, Fusobacterium and Bacteroides species. Conservative management was elected consisting of intravenous antibiotic therapy with ampicillin sodium/sulbactam sodium and metronidazole for 48 h followed by 4 weeks of oral antibiotics. Re-examination 3 months after the initial incident indicated no recurrence of effusion and the cat remained free of clinical signs 2 years after presentation. Relevance and novel information Bacterial pericarditis is a rare cause of pericardial effusion in cats. Growth of P multocida, A canis, Fusobacterium and Bacteroides species has not previously been documented in feline septic pericarditis. Conservative management with broad-spectrum antibiotics may be considered when further diagnostic imaging or exploratory surgery to search for a primary nidus of infection is not feasible or elected.

  4. Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    A. P. F. Pires

    Full Text Available Abstract Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems.

  5. Forensic identification using skin bacterial communities

    OpenAIRE

    FIERER Noah; Lauber, Christian L.; Zhou, Nick; McDonald, Daniel; Costello, Elizabeth K.; Knight, Rob

    2010-01-01

    Recent work has demonstrated that the diversity of skin-associated bacterial communities is far higher than previously recognized, with a high degree of interindividual variability in the composition of bacterial communities. Given that skin bacterial communities are personalized, we hypothesized that we could use the residual skin bacteria left on objects for forensic identification, matching the bacteria on the object to the skin-associated bacteria of the individual who touched the object....

  6. Drag Reduction of Bacterial Cellulose Suspensions

    Directory of Open Access Journals (Sweden)

    Satoshi Ogata

    2011-01-01

    Full Text Available 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 mechanical shear.

  7. In vivo bacterial morphogenetic protein interactions

    OpenAIRE

    van der Ploeg, R.; den Blaauwen, T.; Meghea, A.

    2012-01-01

    This chapter will discuss none-invasive techniques that are widely used to study protein-protein interactions. As an example, their application in exploring interactions between proteins involved in bacterial cell division will be evaluated. First, bacterial morphology and cell division of the rod-shaped bacterium Escherichia coli will be introduced. Next, three bacterial two-hybrid methods and three Förster resonance energy transfer detection methods that are frequently applied to detect int...

  8. Bacterial contamination of hospital physicians' stethoscopes.

    Science.gov (United States)

    Bernard, L; Kereveur, A; Durand, D; Gonot, J; Goldstein, F; Mainardi, J L; Acar, J; Carlet, J

    1999-09-01

    Because stethoscopes might be potential vectors of nosocomial infections, this study, conducted in a 450-bed general hospital, was devised to evaluate the bacterial contamination of stethoscopes; bacterial survival on stethoscope membranes; the kinetics of the bacterial load on stethoscope membranes during clinical use; and the efficacy of 70% alcohol or liquid soap for membrane disinfection. Among the 355 stethoscopes tested, 234 carried > or =2 different bacterial species; 31 carried potentially pathogenic bacteria. Although some bacteria deposited onto membranes could survive 6 to 18 hours, none survived after disinfection.

  9. Bacterial Nanocellulose as a Microbiological Derived Nanomaterial

    Directory of Open Access Journals (Sweden)

    Stanisławska A.

    2016-12-01

    Full Text Available Bacterial nanocellulose (BNC is a nanofibrilar polymer produced by strains such as Gluconacetobacter xylinus, one of the best bacterial species which given the highest efficiency in cellulose production. Bacterial cellulose is a biomaterial having unique properties such as: chemical purity, good mechanical strength, high flexibility, high absorbency, possibility of forming any shape and size and many others. Such a large number of advantages contributes to the widespread use of the BNC in food technology, paper, electronic industry, but also the architecture in use. However, the greatest hopes are using the BNC in medicine. This text contains information about bacterial nanocellulose, its specific mechanical and biological properties and current applications.

  10. Evaluation of rocket resistance to Fusarium wilt%芝麻菜品种对尖镰孢菌枯萎病的抗性评价

    Institute of Scientific and Technical Information of China (English)

    陈国康; Gilardi Giovanna; Gullino Maria Lodovica

    2007-01-01

    尖镰孢菌枯萎病是意大利西北部芝麻菜栽培品种(Eruca vesicaria)和野生品种(Diplotaxis spp.)上的重要病害之一,常引起严重的损失.为评价芝麻菜品种对尖镰孢菌枯萎病的抗性,2004年6 ~11月,选用了44个栽培及野生品种资源在玻璃温室进行抗性试验,使用浓度为1×106 cfu/mL的孢子悬浮液蘸根法人工接种30天苗龄的芝麻菜幼苗,以分离自芝麻菜两个不同野生品种的菌株Fus.Ruc.9A/02和Fus.Ruc.13/03,以及分离自栽培和野生品种的32个菌株混合(MIX),分别作为抗病试验接种体,每次接种试验设A、B、C三个重复.整个试验重复进行2次.调查病害引起的死苗率(%)和病情指数(DI), 作为评价芝麻菜品种抗性差异的两项指标. 研究结果显示,这两项指标间的相关性极显著(P<0.01),即表明可采用其中一项指标评价芝麻菜品种对尖镰孢菌枯萎病的抗性.供试的44个栽培及野生芝麻菜品种中,多数品种抗尖镰孢菌菌株Fus.Ruc.13/03,而对菌株Fus.Ruc.9A/02及菌株混合MIX表现为易感性,而且这些易感品种在菌株Fus.Ruc.9A/02及菌株混合MIX两试验中的抗性表现较为一致,Fus.Ruc.9A/02和MIX的毒性也更强于Fus.Ruc.13/03菌株.芝麻菜品种12/03 和品种 20/03高抗菌株混合MIX,品种 6/03和品种 7/04高抗菌株Fus.Ruc.9A/02,而品种9/02、2/03、5/03、6/03、7/03、9/03、11/03、12/03、20/03、21/03、24/03、3/04、6/04、7/04 和11/04高抗菌株Fus.Ruc.13/03.%In north-western Italy serious losses were observed in cultivated (Eruca vesicaria) and wild (Diplotaxis spp.) rocket varieties infected by Fusarium oxysporum, as one of important diseases in horticultural production. For the evaluation of varietal resistance of rocket to Fusarium wilt, forty-four varieties of rocket, belonging to cultivated and wild rockets, respectively, were chosen for resistance test carried out in glasshouse from June to November, 2004. Roots of 30 day old plants

  11. Extended recombinant bacterial ghost system.

    Science.gov (United States)

    Lubitz, W; Witte, A; Eko, F O; Kamal, M; Jechlinger, W; Brand, E; Marchart, J; Haidinger, W; Huter, V; Felnerova, D; Stralis-Alves, N; Lechleitner, S; Melzer, H; Szostak, M P; Resch, S; Mader, H; Kuen, B; Mayr, B; Mayrhofer, P; Geretschläger, R; Haslberger, A; Hensel, A

    1999-08-20

    Controlled expression of cloned PhiX174 gene E in Gram-negative bacteria results in lysis of the bacteria by formation of an E-specific transmembrane tunnel structure built through the cell envelope complex. Bacterial ghosts from a variety of bacteria are used as non-living candidate vaccines. In the recombinant ghost system, foreign proteins are attached on the inside of the inner membrane as fusions with specific anchor sequences. Ghosts have a sealed periplasmic space and the export of proteins into this space vastly extends the capacity of ghosts or recombinant ghosts to function as carriers of foreign antigens. In addition, S-layer proteins forming shell-like self assembly structures can be expressed in candidate vaccine strains prior to E-mediated lysis. Such recombinant S-layer proteins carrying foreign epitopes further extend the possibilities of ghosts as carriers of foreign epitopes. As ghosts have inherent adjuvant properties, they can be used as adjuvants in combination with subunit vaccines. Subunits or other ligands can also be coupled to matrixes like dextran which are used to fill the internal lumen of ghosts. Oral, aerogenic or parenteral immunization of experimental animals with recombinant ghosts induced specific humoral and cellular immune responses against bacterial and target components including protective mucosal immunity. The most relevant advantage of recombinant bacterial ghosts as immunogens is that no inactivation procedures that denature relevant immunogenic determinants are employed in this production. This fact explains the superior quality of ghosts when compared to other inactivated vaccines. The endotoxic component of the outer membrane does not limit the use of ghosts as vaccine candidates but triggers the release of several potent immunoregulatory cytokines. As carriers, there is no limitation in the size of foreign antigens that can be inserted in the membrane and the capacity of all spaces including the membranes, peri

  12. New pathways for bacterial polythioesters.

    Science.gov (United States)

    Wübbeler, Jan Hendrik; Steinbüchel, Alexander

    2014-10-01

    Polythioesters (PTE) contain sulfur in the backbone and represent persistent biopolymers, which are produced by certain chemical procedures as well as biotechnological in vitro and in vivo techniques. Different building blocks can be incorporated, resulting in PTE with variable features that could become interesting for special purposes. Particularly, the option to produce PTE in large-scale and in accordance with the methods of white biotechnology or green chemistry is valuable due to economical potentials and public environmental consciousness. This review is focused on the synthesis of PTE by the three established bacterial production strains Ralstonia eutropha, Escherichia coli and Advenella mimigardefordensis. In addition, an overview of the in vitro production and degradation of PTE is depicted.

  13. Cooperative Model of Bacterial Sensing

    CERN Document Server

    Shi, Y; Shi, Yu; Duke, Thomas

    1998-01-01

    Bacterial chemotaxis is controlled by the signalling of a cluster of receptors. A cooperative model is presented, in which coupling between neighbouring receptor dimers enhances the sensitivity with which stimuli can be detected, without diminishing the range of chemoeffector concentration over which chemotaxis can operate. Individual receptor dimers have two stable conformational states: one active, one inactive. Noise gives rise to a distribution between these states, with the probability influenced by ligand binding, and also by the conformational states of adjacent receptor dimers. The two-state model is solved, based on an equivalence with the Ising model in a randomly distributed magnetic field. The model has only two effective parameters, and unifies a number of experimental findings. According to the value of the parameter comparing coupling and noise, the signal can be arbitrarily sensitive to changes in the fraction of receptor dimers to which ligand is bound. The counteracting effect of a change of...

  14. Antigenic Variation in Bacterial Pathogens.

    Science.gov (United States)

    Palmer, Guy H; Bankhead, Troy; Seifert, H Steven

    2016-02-01

    Antigenic variation is a strategy used by a broad diversity of microbial pathogens to persist within the mammalian host. Whereas viruses make use of a minimal proofreading capacity combined with large amounts of progeny to use random mutation for variant generation, antigenically variant bacteria have evolved mechanisms which use a stable genome, which aids in protecting the fitness of the progeny. Here, three well-characterized and highly antigenically variant bacterial pathogens are discussed: Anaplasma, Borrelia, and Neisseria. These three pathogens display a variety of mechanisms used to create the structural and antigenic variation needed for immune escape and long-term persistence. Intrahost antigenic variation is the focus; however, the role of these immune escape mechanisms at the population level is also presented.

  15. 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.

  16. 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.

  17. Bacterial Ice Crystal Controlling Proteins

    Directory of Open Access Journals (Sweden)

    Janet S. H. Lorv

    2014-01-01

    Full Text Available Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although both protein classes have differing functions, these proteins use the same ice binding mechanisms. Rather than direct binding, it is probable that these protein classes create an ice surface prior to ice crystal surface adsorption. Function is differentiated by molecular size of the protein. This paper reviews the similar and different aspects of bacterial antifreeze and ice nucleation proteins, the role of these proteins in freezing tolerance, prevalence of these proteins in psychrophiles, and current mechanisms of protein-ice interactions.

  18. 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.

  19. Degradação ruminal de silagem de capim-elefante emurchecido ou com diferentes níveis de farelo de cacau Ruminal degradation of silage of elephantgrass wilted or with different levels of cocoa meal

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2008-08-01

    Full Text Available O experimento foi conduzido para avaliar a degradação ruminal de matéria seca (MS, proteína bruta (PB e fibra em detergente neutro (FDN de silagens de capim-elefante submetido a emurchecimento ou à adição de 0, 7, 14, 21 ou 28% de farelo de cacau (FC durante a ensilagem. Amostras de cada silagem foram incubadas no rúmen de três vacas holandesas por períodos de 0, 6, 12, 24, 48, 72, 96, 120 e 144 horas. A inclusão do farelo de cacau reduziu o potencial de degradação da MS, que foi maior nas silagens com capim emurchecido e não-emurchecido. A degradabilidade potencial da PB e da FDN, no entanto, apresentou pequenas variações e os valores médios situaram-se próximos de 80 e 46%, respectivamente. Considerando a taxa de passagem de 5%/hora, todas as silagens apresentaram elevada degradabilidade efetiva da PB (acima de 55%. Embora as estimativas da degradação ruminal das silagens com farelo de cacau tenham apresentado tendência de redução, todas as silagens apresentaram degradabilidade potencial da MS e da PB acima de 65 e 75%, respectivamente. A adição de farelo de cacau ao capim-elefante pode ser uma alternativa para rápida e abundante disponibilidade de nutrientes para o sistema ruminal.The experiment was conducted to evaluate dry matter (DM, crude protein (CP, and neutral detergent fiber (NDF ruminal degradation of elephantgrass silages wilted under the sun light for eight hours or with addition of 0, 7, 14, 21, and 28% of cocoa meal (CM at the ensiling. Samples of each silage type were incubated in the rumen of three Holstein cows for 0, 6, 12, 24, 48, 72, 96, 120, and 144 hours. The CM inclusion reduced the degradation potential of DM, which showed greater values for silages without CM (wilted or non-wilted. The CP and NDF potential degradability showed small variations, with mean values near 80 and 46%, respectively. Considering a passage rate of 5%/h, all silages showed high CP effective degradability (over 55

  20. Multiple bacterial species reside in chronic wounds

    DEFF Research Database (Denmark)

    Gjødsbøl, Kristine; Christensen, Jens Jørgen; Karlsmark, Tonny;

    2006-01-01

    The aim of the study was to investigate the bacterial profile of chronic venous leg ulcers and the importance of the profile to ulcer development. Patients with persisting venous leg ulcers were included and followed for 8 weeks. Every second week, ulcer samples were collected and the bacterial s...

  1. 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....

  2. Bacterial Flora of the Female Genital Tract

    Directory of Open Access Journals (Sweden)

    Pongsakdi Chaisilwattana

    1995-01-01

    Full Text Available Objective: The purpose of this study was to analyze the ability of septicemic and nonsepticemic isolates of group B streptococci (GBS to inhibit in vitro the principal bacterial groups found in the normal bacterial flora of the female genital tract.

  3. Use of Bacteriophages to control bacterial pathogens

    Science.gov (United States)

    Lytic bacteriophages can provide a natural method and an effective alternative to antibiotics to reduce bacterial pathogens in animals, foods, and other environments. Bacteriophages (phages) are viruses which infect bacterial cells and eventually kill them through lysis, and represent the most abun...

  4. Cerebral infarction in childhood bacterial meningitis

    OpenAIRE

    Snyder, R.D.; Stovring, J; Cushing, A H; Davis, L. E.; Hardy, T. L.

    1981-01-01

    Forty-nine children with complicated bacterial meningitis were studied. Thirteen had abnormalities on computed tomography compatible with the diagnosis of brain infarction; one had a brain biopsy with the histological appearance of infarction. Factors exist in childhood bacterial meningitis which are associated with the development of brain infraction.

  5. In vivo bacterial morphogenetic protein interactions

    NARCIS (Netherlands)

    van der Ploeg, R.; den Blaauwen, T.; Meghea, A.

    2012-01-01

    This chapter will discuss none-invasive techniques that are widely used to study protein-protein interactions. As an example, their application in exploring interactions between proteins involved in bacterial cell division will be evaluated. First, bacterial morphology and cell division of the rod-s

  6. Structural biology of bacterial RNA polymerase.

    Science.gov (United States)

    Murakami, Katsuhiko S

    2015-05-11

    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.

  7. Oral bacterial DNA findings in pericardial fluid

    Directory of Open Access Journals (Sweden)

    Anne-Mari Louhelainen

    2014-11-01

    Full Text Available Background: We recently reported that large amounts of oral bacterial DNA can be found in thrombus aspirates of myocardial infarction patients. Some case reports describe bacterial findings in pericardial fluid, mostly done with conventional culturing and a few with PCR; in purulent pericarditis, nevertheless, bacterial PCR has not been used as a diagnostic method before. Objective: To find out whether bacterial DNA can be measured in the pericardial fluid and if it correlates with pathologic–anatomic findings linked to cardiovascular diseases. Methods: Twenty-two pericardial aspirates were collected aseptically prior to forensic autopsy at Tampere University Hospital during 2009–2010. Of the autopsies, 10 (45.5% were free of coronary artery disease (CAD, 7 (31.8% had mild and 5 (22.7% had severe CAD. Bacterial DNA amounts were determined using real-time quantitative PCR with specific primers and probes for all bacterial strains associated with endodontic disease (Streptococcus mitis group, Streptococcus anginosus group, Staphylococcus aureus/Staphylococcus epidermidis, Prevotella intermedia, Parvimonas micra and periodontal disease (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Fusobacterium nucleatus, and Dialister pneumosintes. Results: Of 22 cases, 14 (63.6% were positive for endodontic and 8 (36.4% for periodontal-disease-associated bacteria. Only one case was positive for bacterial culturing. There was a statistically significant association between the relative amount of bacterial DNA in the pericardial fluid and the severity of CAD (p=0.035. Conclusions: Oral bacterial DNA was detectable in pericardial fluid and an association between the severity of CAD and the total amount of bacterial DNA in pericardial fluid was found, suggesting that this kind of measurement might be useful for clinical purposes.

  8. Isolation and Identification of Antagonistic Streptomyces spp. Against Fusarium Wilt of Watermelon and Primarily Potted Inhibition Test%西瓜枯萎病拮抗链霉菌分离鉴定及盆栽抗病试验

    Institute of Scientific and Technical Information of China (English)

    任迁琪; 宋星林; 吴洪生; 李季; 陈素云; 徐亚; 姚东良; 赵月; 陈健; 李美颖

    2016-01-01

    旨在筛选出能高效抑制西瓜枯萎病病原菌尖孢镰刀菌(Fusarium oxysporum f. sp. niveum)的天然拮抗菌。采用梯度稀释法分离连作辣椒根际土中的放线菌,纯化后用平板对峙法筛选出有拮抗作用的菌株,采用盆钵育苗基质拌菌法接种,进行盆栽抗病试验,并对拮抗效果最佳的菌株进行鉴定。结果显示,从连作辣椒根际土中,分离筛选出10株对西瓜枯萎病有拮抗作用的放线菌,其中菌株 F22、F23、F32的拮抗作用显著。96 h 抑菌圈直径分别达到1.70、1.17和1.47 cm。盆栽试验结果表明,拮抗菌株 F32对西瓜枯萎病30 d 的防治效果最佳,防效率达到66.7%,且抗菌谱性广。根据表型特征、生理生化特性和16S rDNA 分子鉴定结果可知,菌株 F32为链霉菌属(Streptomyces sp.),且对西瓜枯萎病有良好的防治作用,是一株具有应用价值的生防菌株。%The objective is to select a natural antagonistic bacterium efficiently controlling Fusarium oxysporum f. sp. niveum that is the pathogenic bacterium of the fusarium wilt of watermelon. Using the method of gradient dilution to isolate actinomycetes from rhizosphere soil of continuous cropping pepper,it was purified and the plate confrontation method was applied to select an antagonistic strain. Then the method of basin nursery substrates mixed with bacteria was for inoculation,a potted plant disease-resistant experiment was carried out,and the strains with the optimal antagonistic effects were identified. The results showed that 10 strains of actinomycetes with the antagonistic effects to fusarium wilt of watermelon were isolated from the growing pepper rhizosphere soil,and 3 of them(F22,F23 and F32)presented the significantly antagonistic effects. After 96 hours the diameter of the inhibition zone was 1.70 cm,1.17 cm and 1.47 cm respectively. The result of the potted plant experiments demonstrated that the control effect of the

  9. 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

  10. The correlation between soil factors and the occurrence of banana fusarium wilt%蕉园土壤因子与香蕉枯萎病发病的相关性研究

    Institute of Scientific and Technical Information of China (English)

    邓晓; 李勤奋; 侯宪文; 武春媛; 李光义; 洪葵

    2012-01-01

    香蕉枯萎病(Fusarium oysporum f.cubense)是当前严重威胁我国华南地区香蕉生产的重要土传病害,目前尚未找到有效的防治方法.于2010年采集了3个典型香蕉枯萎病患病样地(尖峰、冲坡、十月田)和2个健康样地(临高、广州)的根际与非根际土壤样品共46份,采用常规分析方法测定了19项土壤理化指标含量.旨在从农艺措施的角度考虑香蕉枯萎病的防治提供理论依据.结果表明:健康蕉园的大多理化性状和养分含量高于患病蕉园.尤以土壤粘粒、有机质、CEC、全N、全P、有效P、有效Cu、有效Fe、有效B和交换性Ca含量表现更为明显,其在健康蕉园中的含量均为患病蕉同的1.5倍以上.同一患病蕉园根际土壤中的pH值随植株感病级别增加而上升,而有效P和有效B含量随植株感病级别增加而降低.由此可以推论,在蕉园适当增施P肥和B肥有助于抑制香蕉枯萎病发生.%Currently banana fusarium wilt (Fusarium oysporum f. cubense) is one of the important soil-borne diseases of seriously threat to banana production in Southern China. However, there is no effective method for prevention in the world. The objective of this study was providing research information for the prevention of banana fusarium wilt from the perspective of agronomic measures. Forty-six rhizosphere and non-rhizosphere soil samples were collected from three typical plots (Jianfeng, Shiyuetian, Chongpo) infected by banana fusarium wilt and two healthy banana plots (Lingao, Guangzhou) in 2010. Nineteen soil physical and chemical properties and nutrient concentrations were chemically determined. The results indicated that most of the physical and chemical index and nutrient concentrations of rhizosphere and non-rhizosphere soil from healthy banana plantation were higher than the diseased ones. Especially in the concentrations of soil clay, organic matter, cation exchange capacity, total nitrogen, total phosphorus

  11. 番茄枯萎病致病镰刀菌种类鉴定及优势种群的研究%Identification of the pathogenic and dominant Fusarium species causing tomato Fusarium wilt

    Institute of Scientific and Technical Information of China (English)

    张斌; 杨晓云; 陈志谊

    2016-01-01

    In order to clarify the current Fusarium species and the dominant species causing tomato Fusarium wilt in Tongshan,Qintong and Shuyang.12 soil samples were collected from tomato rhizosphere and the pathogens were isolated.Fusarium species were identified on the basis of morphological characteristics and ITS sequences,and their pathogenicity was also tested.Three Fusarium species,namely F.oxysporum,F.solani and F.verticillioides,were classified with the numbers of 111,32 and 7,respectively.The result of analysis of the Fusarium species distribution in different regions indicated that Fusarium oxysporum was the dominant species in Tongshan,Qintong and Shuyang with frequencies of 66%,72% and 84%,respectively.

  12. Valor nutritivo de silagens de capim-elefante emurchecido ou com adição de farelo de cacau Nutritive value of elephantgrass silage wilted or with addition of cocoa meal

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2007-10-01

    Full Text Available O experimento foi conduzido para avaliar o valor nutritivo da silagem de capim-elefante produzida com o capim emurchecido ou adicionada de diferentes níveis de farelo de cacau. O capim-elefante foi colhido aos 50 dias de rebrota após o corte de uniformização e submetido aos seguintes tratamentos na ensilagem: capim-elefante emurchecido ao sol por 8 horas, e capim-elefante sem emurchecimento com 0, 7, 14, 21 e 28% de farelo de cacau (FC (% da matéria natural. Foram utilizadas quatro repetições por tratamento; o material foi acondicionado em silos de PVC com 0,15 m de diâmetro e 0,3 m de altura, adotando-se compactação de 500 kg/m³. A inclusão do farelo de cacau na ensilagem do capim-elefante mostrou-se eficiente em aumentar o teor de MS da silagem. A inclusão de FC no nível de 7% permitiu produção de silagem com teor de MS semelhante ao da silagem de capim emurchecido. As silagens com FC apresentaram maiores teores de NT, EE, lignina, NIDN e NIDA, no entanto, os teores de FDN, FDA CEL, HEM, cinzas e NDT e a DIVMS diminuíram com a adição de farelo de cacau. O NDT estimado para a silagem de capim emurchecido foi superior ao obtido nas demais silagens, com e sem farelo de cacau. Embora o FC tenha promovido redução da DIVMS, sua inclusão nos níveis de 7 e 14% proporcionou boa digestibilidade das silagens (acima de 60%. O emurchecimento do capim-elefante e a adição de FC podem ser alternativas para aumentar o teor de MS da silagem e garantir a produção de silagens de bom valor nutritivo.The experiment was carried out to evaluate the nutritive value of elephant grass silage wilted 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 process. The PVC silos used in the experiment measured 0.15 m of diameter and 0.30 m of height. During the ensiling process the forage was compressed until

  13. 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

  14. Bacterial Histidine Kinases as Novel Antibacterial Drug Targets

    NARCIS (Netherlands)

    Bem, A.E.; Velikova, N.R.; Pellicer, M.T.; Baarlen, van P.; Marina, A.; Wells, J.M.

    2015-01-01

    Bacterial histidine kinases (HKs) are promising targets for novel antibacterials. Bacterial HKs are part of bacterial two-component systems (TCSs), the main signal transduction pathways in bacteria, regulating various processes including virulence, secretion systems and antibiotic resistance. In thi

  15. Effects of different fertilization treatments on soil fertility, verticillium wilt and yield of eggplant%不同肥料对土壤肥力、茄子黄萎病和产量的影响

    Institute of Scientific and Technical Information of China (English)

    帅正彬; 席春奕; 杨斌; 郭江洪; 赵开平

    2016-01-01

    Using ‘Huaxiajiaozi’ eggplant as the material, a field experiment was conducted to evaluate the effects of different fertilization treatments on soil fertility, microorganism’s community structure, and resistance to verticillium wilt. Compared to the control, treatments adding microbial compound fertilizer or biological organic fertilizer could improve the nutrient structure of soil, optimize the structure of microbial flora, reduce the incidence of eggplant verticillium wilt, and increase the yield. Considering the factors of soil fertility, resistance to disease and yield of eggplant, treatment of 22 kg/667 m2 calcium magnesium phosphate, 8 kg/667 m2 potassium chloride, 100 kg/667 m2 shanxichangxin microbial compound fertilizer, was recommended as the optimal fertilizer combination in planting eggplant.%以‘华夏骄子’茄为试验材料,研究不同施肥处理对土壤营养状况、微生物特性、茄子抗黄萎病和产量的影响。结果表明,与常规施肥相比,其他施肥处理可不同程度地提高土壤养分、优化微生物菌群结构,同时能降低茄子黄萎病的发病率、提高茄子产量。综合考虑土壤、抗病性和产量等因素,推荐最佳施肥方案为钙镁磷肥22 kg/667 m2+氯化钾8 kg/667 m2+山西昌鑫微生物复合肥100 kg/667 m2。

  16. BIOSYNTHESIS OF BACTERIAL CELLULOSE BY МEDUSOMYCES GISEVII

    OpenAIRE

    E. K. Gladysheva; E. A. Skiba

    2015-01-01

    Summary: Bacterial cellulose is an organic material that is synthesized by microorganisms extracellularly. Bacterial cellulose can be used in various industries. Especially, bacterial cellulose has found its application basically in medicine. The production of bacterial cellulose is a complicated and long process. The principal criterion for the process to be successful is bacterial cellulose to be obtained in a higher yield. Russia is lacking an operating facility to produce bacterial cellul...

  17. 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.

  18. Initiation of bacterial spore germination.

    Science.gov (United States)

    Vary, J C; Halvorson, H O

    1968-04-01

    To investigate the problem of initiation in bacterial spore germination, we isolated, from extracts of dormant spores of Bacillus cereus strain T and B. licheniformis, a protein that initiated spore germination when added to a suspension of heat-activated spores. The optimal conditions for initiatory activity of this protein (the initiator) were 30 C in 0.01 to 0.04 m NaCl and 0.01 m tris(hydroxymethyl)aminomethane (pH 8.5). The initiator was inhibited by phosphate but required two co-factors, l-alanine (1/7 of K(m) for l-alanine-inhibited germination) and nicotinamide adenine dinucleotide (1.25 x 10(-4)m). In the crude extract, the initiator activity was increased 3.5-fold by heating the extract at 65 C for 10 min, but the partially purified initiator preparation was completely heat-sensitive (65 C for 5 min). Heat stability could be conferred on the purified initiator by adding 10(-3)m dipicolinic acid. A fractionation of this protein that excluded l-alanine dehydrogenase and adenosine deaminase from the initiator activity was developed. The molecular weight of the initiator was estimated as 7 x 10(4). The kinetics of germination in the presence of initiator were examined at various concentrations of l-alanine and nicotinamide adenine dinucleotide.

  19. Phenotypic plasticity in bacterial plasmids.

    Science.gov (United States)

    Turner, Paul E

    2004-01-01

    Plasmid pB15 was previously shown to evolve increased horizontal (infectious) transfer at the expense of reduced vertical (intergenerational) transfer and vice versa, a key trade-off assumed in theories of parasite virulence. Whereas the models predict that susceptible host abundance should determine which mode of transfer is selectively favored, host density failed to mediate the trade-off in pB15. One possibility is that the plasmid's transfer deviates from the assumption that horizontal spread (conjugation) occurs in direct proportion to cell density. I tested this hypothesis using Escherichia coli/pB15 associations in laboratory serial culture. Contrary to most models of plasmid transfer kinetics, my data show that pB15 invades static (nonshaking) bacterial cultures only at intermediate densities. The results can be explained by phenotypic plasticity in traits governing plasmid transfer. As cells become more numerous, the plasmid's conjugative transfer unexpectedly declines, while the trade-off between transmission routes causes vertical transfer to increase. Thus, at intermediate densities the plasmid's horizontal transfer can offset selection against plasmid-bearing cells, but at high densities pB15 conjugates so poorly that it cannot invade. I discuss adaptive vs. nonadaptive causes for the phenotypic plasticity, as well as potential mechanisms that may lead to complex transfer dynamics of plasmids in liquid environments. PMID:15166133

  20. Acute bacterial sinusitis in children.

    Science.gov (United States)

    DeMuri, Gregory; Wald, Ellen R

    2013-10-01

    On the basis of strong research evidence, the pathogenesis of sinusitis involves 3 key factors: sinusostia obstruction, ciliary dysfunction, and thickening of sinus secretions. On the basis of studies of the microbiology of otitis media, H influenzae is playing an increasingly important role in the etiology of sinusitis, exceeding that of S pneumoniae in some areas, and b-lactamase production by H influenzae is increasing in respiratory isolates in the United States. On the basis of some research evidence and consensus,the presentation of acute bacterial sinusitis conforms to 1 of 3 predicable patterns; persistent, severe, and worsening symptoms. On the basis of some research evidence and consensus,the diagnosis of sinusitis should be made by applying strict clinical criteria. This approach will select children with upper respiratory infection symptoms who are most likely to benefit from an antibiotic. On the basis of some research evidence and consensus,imaging is not indicated routinely in the diagnosis of sinusitis. Computed tomography or magnetic resonance imaging provides useful information when complications of sinusitis are suspected. On the basis of some research evidence and consensus,amoxicillin-clavulanate should be considered asa first-line agent for the treatment of sinusitis.

  1. 凋萎和添加剂对王草青贮品质和营养价值的影响%Effects of Wilted and Additive on Silage Quality and Nutritional Value of King Grass

    Institute of Scientific and Technical Information of China (English)

    李茂; 字学娟; 张英; 周汉林; 白昌军; 刘国道

    2014-01-01

    This experiment was conducted to study the effects of wilt and additive [ pre-fermented juice ( PFJ) and cellulose enzyme ( C) ] on silage quality and nutritional value of king grass. The groups were as follows:control, wilted ( W) , wilted+PFJ ( WP) , wilted+C ( WP) and wilted+PFJ+C ( WPC) . The silos of each group were opened and analyzed after 30 days ensilage. The results showed as follows:1) the pH of all groups were lower than 4.0, the pH in control group was significantly lower than that in W group (P<0.05), and WPC group had lowest pH. The lactic acid content in WPC group was the highest, and significantly higher than that in control group ( P<0.05) . The acetic acid content in control group was significantly higher than that in other groups ( P<0.05) , the acetic acid content in W group was significantly lower than that in other groups (P<0.05). All groups had no butyric acid detected. The ammonia-N/total nitrogen ( AN/TN) in control group was significantly higher than that in other groups ( P<0.05) , the AN/TN in WPC group was significant-ly lower than that in other groups (P<0.05). 2) According to the grade of V-Score, silage quality of all groups were well, the score of control group had lowest score (83.45), and the scores of groups W, WP and WPC were higher than that in control group ( more than 95) . 3) The WPC group had the highest crude protein content and relative feed value ( RFV) , also it had the lowest neutral detergent fiber and acid detergent fiber content, all above was significantly higher than that in other groups ( P<0.05) . It is concluded that the silage quality of king grass silage without treatment is well but nutritional value is low, wilted king grass supplemen-ted with PFJ+C mixed silage can improve the silage quality and nutritional value.%本试验旨在探讨凋萎和添加剂(绿汁发酵液、纤维素酶)对王草青贮品质和营养价值的影响。试验设对照组、凋萎( W)组、凋萎+绿汁发酵液( WP

  2. Marine mesocosm bacterial colonisation of volcanic ash

    Science.gov (United States)

    Witt, Verena; Cimarelli, Corrado; Ayris, Paul; Kueppers, Ulrich; Erpenbeck, Dirk; Dingwell, Donald; Woerheide, Gert

    2015-04-01

    Volcanic eruptions regularly eject large quantities of ash particles into the atmosphere, which can be deposited via fallout into oceanic environments. Such fallout has the potential to alter pH, light and nutrient availability at local scales. Shallow-water coral reef ecosystems - "rainforests of the sea" - are highly sensitive to disturbances, such as ocean acidification, sedimentation and eutrophication. Therefore, wind-delivered volcanic ash may lead to burial and mortality of such reefs. Coral reef ecosystem resilience may depend on pioneer bacterial colonisation of the ash layer, supporting subsequent establishment of the micro- and ultimately the macro-community. However, which bacteria are involved in pioneer colonisation remain unknown. We hypothesize that physico-chemical properties (i.e., morphology, mineralogy) of the ash may dictate bacterial colonisation. The effect of substrate properties on bacterial colonisation was tested by exposing five substrates: i) quartz sand ii) crystalline ash (Sakurajima, Japan) iii) volcanic glass iv) carbonate reef sand and v) calcite sand of similar grain size, in controlled marine coral reef aquaria under low light conditions for six months. Bacterial communities were screened every month by Automated Ribosomal Intergenic Spacer Analysis of the 16S-23S rRNA Internal Transcribed Spacer region. Multivariate statistics revealed discrete groupings of bacterial communities on substrates of volcanic origin (ash and glass) and reef origin (three sands). Analysis of Similarity supported significantly different communities associated with all substrates (p=0.0001), only quartz did not differ from both carbonate and calcite sands. The ash substrate exhibited the most diverse bacterial community with the most substrate-specific bacterial operational taxonomic units. Our findings suggest that bacterial diversity and community composition during colonisation of volcanic ash in a coral reef-like environment is controlled by the

  3. Bacterial binding to extracellular proteins - in vitro adhesion

    DEFF Research Database (Denmark)

    Schou, C.; Fiehn, N.-E.

    1999-01-01

    Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis......Viridans streptococci, bacterial adherence, extracellular matrix proteins, surface receptors, endocarditis...

  4. 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.

  5. 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.

  6. 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.

  7. Bacterial gasotransmitters: an innate defense against antibiotics.

    Science.gov (United States)

    Luhachack, Lyly; Nudler, Evgeny

    2014-10-01

    In recent decades, there has been growing interest in the field of gasotransmitters, endogenous gaseous signaling molecules (NO, H2S, and CO), as regulators of a multitude of biochemical pathways and physiological processes. Most of the concerted effort has been on eukaryotic gasotransmitters until the subsequent discovery of bacterial counterparts. While the fundamental aspects of bacterial gasotransmitters remain undefined and necessitate further research, we will discuss a known specific role they play in defense against antibiotics. Considering the current dilemma of multidrug-resistant bacteria we consider it particularly prudent to exploring novel targets and approaches, of which the bacterial gasotransmitters, nitric oxide and hydrogen sulfide represent.

  8. Positively regulated bacterial expression systems.

    Science.gov (United States)

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high-level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC-XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (L-arabinose, L-rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone-related compounds, ε-caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC-XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/P(BAD), RhaR-RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications.

  9. Endolymphatic sac involvement in bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Brandt, Christian; Andersen, Christian Østergaard;

    2015-01-01

    The commonest sequelae of bacterial meningitis are related to the inner ear. Little is known about the inner ear immune defense. Evidence suggests that the endolymphatic sac provides some protection against infection. A potential involvement of the endolymphatic sac in bacterial meningitis......-inoculated. The rats were killed when reaching terminal illness or on day 7, followed by light microscopy preparation and PAS-Alcian blue staining. The endolymphatic sac was examined for bacterial invasion and leukocyte infiltration. Neither bacteria nor leukocytes infiltrated the endolymphatic sac during the first...... days. Bacteria invaded the inner ear through the cochlear aquaduct. On days 5-6, the bacteria invaded the endolymphatic sac through the endolymphatic duct subsequent to invasion of the vestibular endolymphatic compartment. No evidence of direct bacterial invasion of the sac through the meninges...

  10. Bacterial bioluminescence in marine pollution assessment

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Chandramohan, D.

    Warm water marine luminous bacterial species, particularly Vibrio harveyi, V. fischeri and Photobacterium leiognathi, are easy to isolate, maintain and handle in the laboratories without strict temperature requirements, which is an important...

  11. The bacterial microbiota in inflammatory lung diseases.

    Science.gov (United States)

    Huffnagle, Gary B; Dickson, Robert P

    2015-08-01

    Numerous lines of evidence, ranging from recent studies back to those in the 1920s, have demonstrated that the lungs are NOT bacteria-free during health. We have recently proposed that the entire respiratory tract should be considered a single ecosystem extending from the nasal and oral cavities to the alveoli, which includes gradients and niches that modulate microbiome dispersion, retention, survival and proliferation. Bacterial exposure and colonization of the lungs during health is most likely constant and transient, respectively. Host microanatomy, cell biology and innate defenses are altered during chronic lung disease, which in turn, alters the dynamics of bacterial turnover in the lungs and can lead to longer term bacterial colonization, as well as blooms of well-recognized respiratory bacterial pathogens. A few new respiratory colonizers have been identified by culture-independent methods, such as Pseudomonas fluorescens; however, the role of these bacteria in respiratory disease remains to be determined.

  12. Respiratory bacterial infections in cystic fibrosis

    DEFF Research Database (Denmark)

    Ciofu, Oana; Hansen, Christine R; Høiby, Niels

    2013-01-01

    Bacterial respiratory infections are the main cause of morbidity and mortality in patients with cystic fibrosis (CF). Pseudomonas aeruginosa remains the main pathogen in adults, but other Gram-negative bacteria such as Achromobacter xylosoxidans and Stenotrophomonas maltophilia as well...

  13. The Bacterial Microbiota in Inflammatory Lung Diseases

    Science.gov (United States)

    Huffnagle, Gary B.; Dickson, Robert P.

    2016-01-01

    Numerous lines of evidence, ranging from recent studies back to those in the 1920's, have demonstrated that the lungs are NOT bacteria-free during health. We have recently proposed that the entire respiratory tract should be considered a single ecosystem extending from the nasal and oral cavities to the alveoli, which includes gradients and niches that modulate microbiome dispersion, retention, survival and proliferation. Bacterial exposure and colonization of the lungs during health is most likely constant and transient, respectively. Host microanatomy, cell biology and innate defenses are altered during chronic lung disease, which in turn, alters the dynamics of bacterial turnover in the lungs and can lead to longer term bacterial colonization, as well as blooms of well-recognized respiratory bacterial pathogens. A few new respiratory colonizers have been identified by culture-independent methods, such as Pseudomonas fluorescens; however, the role of these bacteria in respiratory disease remains to be determined. PMID:26122174

  14. Plant growth-promoting bacterial endophytes.

    Science.gov (United States)

    Santoyo, Gustavo; Moreno-Hagelsieb, Gabriel; Orozco-Mosqueda, Ma del Carmen; Glick, Bernard R

    2016-02-01

    Bacterial endophytes ubiquitously colonize the internal tissues of plants, being found in nearly every plant worldwide. Some endophytes are able to promote the growth of plants. For those strains the mechanisms of plant growth-promotion known to be employed by bacterial endophytes are similar to the mechanisms used by rhizospheric bacteria, e.g., the acquisition of resources needed for plant growth and modulation of plant growth and development. Similar to rhizospheric plant growth-promoting bacteria, endophytic plant growth-promoting bacteria can act to facilitate plant growth in agriculture, horticulture and silviculture as well as in strategies for environmental cleanup (i.e., phytoremediation). Genome comparisons between bacterial endophytes and the genomes of rhizospheric plant growth-promoting bacteria are starting to unveil potential genetic factors involved in an endophytic lifestyle, which should facilitate a better understanding of the functioning of bacterial endophytes.

  15. [Combination therapy of chronic bacterial prostatitis].

    Science.gov (United States)

    Khryanin, A A; Reshetnikov, O V

    2016-08-01

    The article discusses the possible etiological factors in the development of chronic bacterial prostatitis. The authors presented a comparative long-term analysis of morbidity from non-viral sexually transmitted infections (STIs) in Russia. Against the background of general decline in STIs incidence, a significant percentage of them is made up by urogenital trichomoniasis. The findings substantiated the advantages of combination therapy (ornidazole and ofloxacin) for bacterial urinary tract infections.

  16. Jellyfish modulate bacterial dynamic and community structure.

    Science.gov (United States)

    Tinta, Tinkara; Kogovšek, Tjaša; Malej, Alenka; Turk, Valentina

    2012-01-01

    Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE) analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into possible changes in

  17. Jellyfish modulate bacterial dynamic and community structure.

    Directory of Open Access Journals (Sweden)

    Tinkara Tinta

    Full Text Available Jellyfish blooms have increased in coastal areas around the world and the outbreaks have become longer and more frequent over the past few decades. The Mediterranean Sea is among the heavily affected regions and the common bloom-forming taxa are scyphozoans Aurelia aurita s.l., Pelagia noctiluca, and Rhizostoma pulmo. Jellyfish have few natural predators, therefore their carcasses at the termination of a bloom represent an organic-rich substrate that supports rapid bacterial growth, and may have a large impact on the surrounding environment. The focus of this study was to explore whether jellyfish substrate have an impact on bacterial community phylotype selection. We conducted in situ jellyfish-enrichment experiment with three different jellyfish species. Bacterial dynamic together with nutrients were monitored to assess decaying jellyfish-bacteria dynamics. Our results show that jellyfish biomass is characterized by protein rich organic matter, which is highly bioavailable to 'jellyfish-associated' and 'free-living' bacteria, and triggers rapid shifts in bacterial population dynamics and composition. Based on 16S rRNA clone libraries and denaturing gradient gel electrophoresis (DGGE analysis, we observed a rapid shift in community composition from unculturable Alphaproteobacteria to culturable species of Gammaproteobacteria and Flavobacteria. The results of sequence analyses of bacterial isolates and of total bacterial community determined by culture independent genetic analysis showed the dominance of the Pseudoalteromonadaceae and the Vibrionaceae families. Elevated levels of dissolved proteins, dissolved organic and inorganic nutrient release, bacterial abundance and carbon production as well as ammonium concentrations characterized the degradation process. The biochemical composition of jellyfish species may influence changes in the amount of accumulated dissolved organic and inorganic nutrients. Our results can contribute insights into

  18. Pattern Formation in a Bacterial Colony Model

    Directory of Open Access Journals (Sweden)

    Xinze Lian

    2014-01-01

    Full Text Available We investigate the spatiotemporal dynamics of a bacterial colony model. Based on the stability analysis, we derive the conditions for Hopf and Turing bifurcations. Furthermore, we present novel numerical evidence of time evolution of patterns controlled by parameters in the model and find that the model dynamics exhibit a diffusion controlled formation growth to spots, holes and stripes pattern replication, which show that the bacterial colony model is useful in revealing the spatial predation dynamics in the real world.

  19. Asynchronous exponential growth of a bacterial population

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    Mohamed Boulanouar

    2014-01-01

    Full Text Available In this work, we complete a study started earlier in [1,2] wherein a model of growing bacterial population has been the matter of a mathematical analysis. We show that the full model is governed by a strongly continuous semigroup. Beside the positivity and the irreducibility of the generated semigroup, we describe its asymptotic behavior in the uniform topology which leads to the asynchronous exponential growth of the bacterial population.

  20. Volatiles in Inter-Specific Bacterial Interactions.

    Science.gov (United States)

    Tyc, Olaf; Zweers, Hans; de Boer, Wietse; Garbeva, Paolina

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.

  1. Rho-modifying bacterial protein toxins.

    Science.gov (United States)

    Aktories, Klaus

    2015-12-01

    Rho proteins are targets of numerous bacterial protein toxins, which manipulate the GTP-binding proteins by covalent modifications, including ADP ribosylation, glycosylation, adenylylation, proteolytic cleavage and deamidation. Bacterial toxins are important virulence factors but are also potent and efficient pharmacological tools to study the physiological functions of their eukaryotic targets. Recent studies indicate that amazing variations exist in the molecular mechanisms by which toxins attack Rho proteins, which are discussed here.

  2. Mechanistic investigations on six bacterial terpene cyclases

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    Patrick Rabe

    2016-08-01

    Full Text Available The products obtained by incubation of farnesyl diphosphate (FPP with six purified bacterial terpene cyclases were characterised by one- and two-dimensional NMR spectroscopic methods, allowing for a full structure elucidation. The absolute configurations of four terpenes were determined based on their optical rotary powers. Incubation experiments with 13C-labelled isotopomers of FPP in buffers containing water or deuterium oxide allowed for detailed insights into the cyclisation mechanisms of the bacterial terpene cyclases.

  3. Recombination and the nature of bacterial speciation

    OpenAIRE

    2007-01-01

    Genetic surveys are uncovering the diversity of bacteria, and are causing the species concepts used to categorize these to be questioned. One difficulty in defining bacterial species arises from the high rates of recombination that results in the transfer of DNA between relatively distantly related bacteria. Barriers to this process, which could be used to define species naturally, are not apparent. Here, we have reviewed conceptual models of bacterial speciation and simulate speciation in si...

  4. Soil carbon quality and nitrogen fertilization structure bacterial communities with predictable responses of major bacterial phyla

    OpenAIRE

    2014-01-01

    Agricultural practices affect the soil ecosystem in multiple ways and the soil microbial communities represent an integrated and dynamic measure of soil status. Our aim was to test whether the soil bacterial community and the relative abundance of major bacterial phyla responded predictably to long-term organic amendments representing different carbon qualities (peat and straw) in combination with nitrogen fertilization levels and if certain bacterial groups were indicative of specific treatm...

  5. Comprehensive phylogenetic analysis of bacterial reverse transcriptases.

    Directory of Open Access Journals (Sweden)

    Nicolás Toro

    Full Text Available Much less is known about reverse transcriptases (RTs in prokaryotes than in eukaryotes, with most prokaryotic enzymes still uncharacterized. Two surveys involving BLAST searches for RT genes in prokaryotic genomes revealed the presence of large numbers of diverse, uncharacterized RTs and RT-like sequences. Here, using consistent annotation across all sequenced bacterial species from GenBank and other sources via RAST, available from the PATRIC (Pathogenic Resource Integration Center platform, we have compiled the data for currently annotated reverse transcriptases from completely sequenced bacterial genomes. RT sequences are broadly distributed across bacterial phyla, but green sulfur bacteria and cyanobacteria have the highest levels of RT sequence diversity (≤85% identity per genome. By contrast, phylum Actinobacteria, for which a large number of genomes have been sequenced, was found to have a low RT sequence diversity. Phylogenetic analyses revealed that bacterial RTs could be classified into 17 main groups: group II introns, retrons/retron-like RTs, diversity-generating retroelements (DGRs, Abi-like RTs, CRISPR-Cas-associated RTs, group II-like RTs (G2L, and 11 other groups of RTs of unknown function. Proteobacteria had the highest potential functional diversity, as they possessed most of the RT groups. Group II introns and DGRs were the most widely distributed RTs in bacterial phyla. Our results provide insights into bacterial RT phylogeny and the basis for an update of annotation systems based on sequence/domain homology.

  6. Role of quorum sensing in bacterial infections

    Science.gov (United States)

    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. In this review, we discuss the present evidence from in vitro and in vivo experiments in animal models, as well as from clinical studies, that link QS systems with human infections. We focus on two major QS bacterial models, the opportunistic Gram negative bacteria Pseudomonas aeruginosa and the Gram positive Staphylococcus aureus, which are also two of the main agents responsible of nosocomial and wound infections. In addition, QS communication systems in other bacterial, eukaryotic pathogens, and even immune and cancer cells are also reviewed, and finally, the new approaches proposed to combat bacterial infections by the attenuation of their QS communication systems and virulence are also discussed. PMID:26244150

  7. 铜、锌元素对香蕉枯萎病的防治效果与机理%Effects and Mechanism of Copper and Zinc Elements on Controlling Fusarium-wilt Disease of Banana

    Institute of Scientific and Technical Information of China (English)

    姬华伟; 郑青松; 董鲜; 周金燕; 沈其荣; 郭世伟

    2012-01-01

    In order to find the measure of controlling the fusarium wilt disease of banana, through pot experiments and laboratory experiments, we investigated the applied effects of EDTA-Cu and EDTA-Zn on the physiological characteristics of Fusarium oxysporum f. sp. cubense, and the combined application of Zn2+ and the fungal antagonist of the No. 21 bacteria (SQR21#, Paenibacillus polymyxa) on the suppression on the disease. The results were as follows: (1) Time of 96 hours after treatment the banana seedlings with crude toxin of Fusarium oxysporum f. sp. cubense, the seedlings of the control treatment wilted severely. However, the treatments of application of EDTA-Cu and EDTA-Zn significantly reduced the disease stress on banana. (2) Application of EDTA-Cu and EDTA-Zn significantly increased the total biomass and the microconidium number ofFusariurn oxysporum f. sp. cubense, but significantly reduced the production of fusaric acid of Fusarium oxysporum f. sp. cubense. Compared with the controltreatment, the fusaric acid production with treatments of EDTA-Cu and EDTA-Zn were reduced by 73% and 96%, respectively.(3)In pot experiments, only Zn2+ addition significantly reduced the banana fusarium wilt disease index. Furthermore, combined application of Zn2+ and the No. 21 bacteria had a good effect of cotrolling the disease, and after 75 days of inoculation of banana seedlings, the banana fusarium wilt disease indices were all reduced by 62% compared with the only fungi-inoculated treatment. (4) Only addition of the No. 21 bacteria reduced the spore number by 18% compared to the only fungi-inoculated treatment. However, when combined application of Zn and No. 21 bacteria, the number of the spores was increased significantly by 30%. It was concluded that Zn application might effectively reduce the occurrence of fusarium wilt disease of banana though reducing the fusaric acid production of the pathogen and enhancing the No. 21 bacteria biocontrol

  8. 生物有机肥施用期对香蕉枯萎病及土壤微生物的影响%Effects of Biological Fertilizer Applications on Banana Wilt Disease and Soil Microorganisms

    Institute of Scientific and Technical Information of China (English)

    丁文娟; 曹群; 赵兰凤; 刘小峰; 柳影; 杨盼盼; 李华兴

    2014-01-01

    Banana Fusarium Wilt, a soil borne diseases caused by a fungus, has severely affected banana production. Under field conditions, the effects of biological fertilizer on Banana Fusarium Wilt and soil microorganisms were studied using a completely randomized block de-sign. At basal and vegetative stages, applying biological fertilizer combined with chemical fertilizer obviously promoted banana growth, lead-ing to greater stem diameter, blade width and yields of banana after 270 d of transplanting than at other growth stages. When processed in BOF2, the average output of banana per district was up to 288 kg, significantly higher than the rest treatments. Applying biological fertilizer during vegetative period significantly reduced the occurrence of banana wilt and delayed the onset of banana wilt. Compared with the chemi-cal fertilizer control, the disease index was decreased by 54%by biological fertilizer applied at vegetative growth stage. Application of bio-logical fertilizer at the basal stage improved the population of soil bacteria and actinomycetes, but reduced that of fungi. Soil catalase, inver-tase, urease and acid phosphatase activities were all improved by biological fertilizer. The disease index was significantly negatively corre-lated with the number of both bacteria and actinomycetes in soil, but significantly positively with the number of fungi in soil. The findings suggest that application of biological fertilizer at banana vegetative period could improve soil microorganism structure, promote soil enzyme activities, and reduce and/or delay banana wilt disease occurrence.%在大田条件下,采用完全随机区组试验方法研究生物有机肥施用期对香蕉枯萎病和土壤微生物的影响。结果表明,在基肥期(BOF1)和营养生长期(BOF2)施用生物有机肥对香蕉生长表现出明显的促进作用,移栽后第270 d,BOF1和BOF2处理的茎围、叶宽和产量均高于其他处理,BOF2

  9. Antibiotics promote aggregation within aquatic bacterial communities

    Directory of Open Access Journals (Sweden)

    Gianluca eCorno

    2014-07-01

    Full Text Available The release of antibiotics (AB into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and productivity. New approaches are required to study the response of microbial communities rather than individual resistance genes. In this study a chemostat-based experiment with 4 coexisting bacterial strains has been performed to mimicking the response of a freshwater bacterial community to the presence of antibiotics in low and high doses. Bacterial abundance rapidly decreased by 75% in the presence of AB, independently of their concentration, and remained constant until the end of the experiment. The bacterial community was mainly dominated by Aeromonas hydrophila and Brevundimonas intermedia while the other two strains, Micrococcus luteus and Rhodococcus sp. never exceed 10%. Interestingly, the bacterial strains, which were isolated at the end of the experiment, were not AB-resistant, while reassembled communities composed of the 4 strains, isolated from treatments under AB stress, significantly raised their performance (growth rate, abundance in the presence of AB compared to the communities reassembled with strains isolated from the treatment without AB. By investigating the phenotypic adaptations of the communities subjected to the different treatments, we found that the presence of AB significantly increased co-aggregation by 5-6 fold.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

  10. Photoinactivation of major bacterial pathogens in aquaculture

    Directory of Open Access Journals (Sweden)

    Heyong Jin Roh

    2016-08-01

    Full Text Available Abstract Background Significant increases in the bacterial resistance to various antibiotics have been found in fish farms. Non-antibiotic therapies for infectious diseases in aquaculture are needed. In recent years, light-emitting diode technology has been applied to the inactivation of pathogens, especially those affecting humans. The purpose of this study was to assess the effect of blue light (wavelengths 405 and 465 nm on seven major bacterial pathogens that affect fish and shellfish important in aquaculture. Results We successfully demonstrate inactivation activity of a 405/465-nm LED on selected bacterial pathogens. Although some bacteria were not fully inactivated by the 465-nm light, the 405-nm light had a bactericidal effect against all seven pathogens, indicating that blue light can be effective without the addition of a photosensitizer. Photobacterium damselae, Vibrio anguillarum, and Edwardsiella tarda were the most susceptible to the 405-nm light (36.1, 41.2, and 68.4 J cm−2, respectively, produced one log reduction in the bacterial populations, whereas Streptococcus parauberis was the least susceptible (153.8 J cm−2 per one log reduction. In general, optical density (OD values indicated that higher bacterial densities were associated with lower inactivating efficacy, with the exception of P. damselae and Vibrio harveyi. In conclusion, growth of the bacterial fish and shellfish pathogens evaluated in this study was inactivated by exposure to either the 405- or 465-nm light. In addition, inactivation was dependent on exposure time. Conclusions This study presents that blue LED has potentially alternative therapy for treating fish and shellfish bacterial pathogens. It has great advantages in aspect of eco-friendly treating methods differed from antimicrobial methods.

  11. Molecular diagnosis of bacterial vaginosis: Does adjustment for total bacterial load or human cellular content improve diagnostic performance?

    Science.gov (United States)

    Plummer, E L; Garland, S M; Bradshaw, C S; Law, M G; Vodstrcil, L A; Hocking, J S; Fairley, C K; Tabrizi, S N

    2017-02-01

    We investigated the utility of quantitative PCR assays for diagnosis of bacterial vaginosis and found that while the best model utilized bacterial copy number adjusted for total bacterial load (sensitivity=98%, specificity=93%, AUC=0.95[95%CI=0.93,0.97]), adjusting for total bacterial or human cell load did not consistently increase the diagnostic performance of the assays.

  12. Microbial Degradation of Aniline by Bacterial Consortium

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONG WANG; ZE-YU MAO; WEI-ZHONG WU

    2003-01-01

    Objective To investigate the characteristics of microbial degradation of aniline by a stable bacterial consortium. Methods The bacterial consortium was isolated from activated sludge treating chemical wastewater using aniline as the sole source of carbon and nitrogen by enrichment and isolation technique. The biomass was measured as optical density (OD) at 510 nm using a spectrophotometer. Aniline concentrations were determined by spectrophotometer. The intermediates of aniline degradation were identified by GC/MS method. Results The bacterial consortium could grow at a range of aniline concentrations between 50 and 500 mg/L. The optimal pH and temperature for aniline degradation were determined to be 7.0 and 30, respectively. The presence of NH4NO3 as an additional nitrogen source (100-500 mg/L) had no adverse effect on bacterial growth and aniline degradation. The presence of heavy metal ions, such as Co2+, Zn2+, Ni2+, Mn2+ and Cu2+ had an inhibitory effect on aniline degradation. Conclusions The isolated bacterial consortium candegrade aniline up to 500 mg/L effectively and tolerate some heavy metal ions that commonly exist in chemical wastewater. It has a potential to be applied in the practical treatment of aniline-containingwastewater.

  13. Bacterial infections in patients with liver cirrhosis

    Directory of Open Access Journals (Sweden)

    Giacomo Zaccherini

    2011-07-01

    Full Text Available Bacterial infections represent a frequent complication of liver cirrhosis carrying a significantly greater risk of morbidity and mortality as compared to that observed in non-cirrhotic patients. Such unfavourable prognosis is related to the systemic complications (liver and renal failure, shock, coagulopathy, multiple organ failure induced by a series of pro-inflammatory and immunological systems which are activated by bacteria and their pathogenetic products.The epidemiology of bacterial infections in cirrhosis has changed in the last years with a marked increase of Gram+ infections and the emergence of multi-resistant bacteria.The severity of liver disease represents the major clinical factor predisposing to bacterial infections, which are asymptomatic or paucisymptomatic at presentation in almost half of the cases. Aim of this review is to summarise the clinical and therapeutic aspects of bacterial infections in cirrhotic patients. The most common sites of infection are the urinary tract, ascites, blood, lungs and soft tissues.Beside antibiotics, it has been proposed the administration of human albumin to prevent the development of renal failure in patients with spontaneous bacterial peritonitis and, more recently, the use of hydrocortisone to treat cirrhotic patients with septic shock.

  14. Bacterial coinfections in children with viral wheezing.

    Science.gov (United States)

    Lehtinen, P; Jartti, T; Virkki, R; Vuorinen, T; Leinonen, M; Peltola, V; Ruohola, A; Ruuskanen, O

    2006-07-01

    Bacterial coinfections occur in respiratory viral infections, but the attack rates and the clinical profile are not clear. The aim of this study was to determine bacterial coinfections in children hospitalized for acute expiratory wheezing with defined viral etiology. A total of 220 children aged 3 months to 16 years were investigated. The viral etiology of wheezing was confirmed by viral culture, antigen detection, serologic investigation, and/or PCR. Specific antibodies to common respiratory bacteria were measured from acute and convalescent serum samples. All children were examined clinically for acute otitis media, and subgroups of children were examined radiologically for sinusitis and pneumonia. Rhinovirus (32%), respiratory syncytial virus (31%), and enteroviruses (31%) were the most common causative viruses. Serologic evidence of bacterial coinfection was found in 18% of the children. Streptococcus pneumoniae (8%) and Mycoplasma pneumoniae (5%) were the most common causative bacteria. Acute otitis media was diagnosed in 44% of the children. Chest radiographs showed alveolar infiltrates in 10%, and paranasal radiographs and clinical signs showed sinusitis in 17% of the older children studied. Leukocyte counts and serum C-reactive protein levels were low in a great majority of patients. Viral lower respiratory tract infection in children is often associated with bacterial-type upper respiratory tract infections. However, coexisting bacterial lower respiratory tract infections that induce systemic inflammatory response are seldom detected.

  15. Bacterial communities associated with the lichen symbiosis.

    Science.gov (United States)

    Bates, Scott T; Cropsey, Garrett W G; Caporaso, J Gregory; Knight, Rob; Fierer, Noah

    2011-02-01

    Lichens are commonly described as a mutualistic symbiosis between fungi and "algae" (Chlorophyta or Cyanobacteria); however, they also have internal bacterial communities. Recent research suggests that lichen-associated microbes are an integral component of lichen thalli and that the classical view of this symbiotic relationship should be expanded to include bacteria. However, we still have a limited understanding of the phylogenetic structure of these communities and their variability across lichen species. To address these knowledge gaps, we used bar-coded pyrosequencing to survey the bacterial communities associated with lichens. Bacterial sequences obtained from four lichen species at multiple locations on rock outcrops suggested that each lichen species harbored a distinct community and that all communities were dominated by Alphaproteobacteria. Across all samples, we recovered numerous bacterial phylotypes that were closely related to sequences isolated from lichens in prior investigations, including those from a lichen-associated Rhizobiales lineage (LAR1; putative N(2) fixers). LAR1-related phylotypes were relatively abundant and were found in all four lichen species, and many sequences closely related to other known N(2) fixers (e.g., Azospirillum, Bradyrhizobium, and Frankia) were recovered. Our findings confirm the presence of highly structured bacterial communities within lichens and provide additional evidence that these bacteria may serve distinct functional roles within lichen symbioses.

  16. Emerging bacterial pathogens: the past and beyond.

    Science.gov (United States)

    Vouga, M; Greub, G

    2016-01-01

    Since the 1950s, medical communities have been facing with emerging and reemerging infectious diseases, and emerging pathogens are now considered to be a major microbiologic public health threat. In this review, we focus on bacterial emerging diseases and explore factors involved in their emergence as well as future challenges. We identified 26 major emerging and reemerging infectious diseases of bacterial origin; most of them originated either from an animal and are considered to be zoonoses or from water sources. Major contributing factors in the emergence of these bacterial infections are: (1) development of new diagnostic tools, such as improvements in culture methods, development of molecular techniques and implementation of mass spectrometry in microbiology; (2) increase in human exposure to bacterial pathogens as a result of sociodemographic and environmental changes; and (3) emergence of more virulent bacterial strains and opportunistic infections, especially affecting immunocompromised populations. A precise definition of their implications in human disease is challenging and requires the comprehensive integration of microbiological, clinical and epidemiologic aspects as well as the use of experimental models. It is now urgent to allocate financial resources to gather international data to provide a better understanding of the clinical relevance of these waterborne and zoonotic emerging diseases.

  17. Detection and identification of banana Fusarium wilt pathogen (FOC4) in Guangxi%广西香蕉枯萎病病原菌4号生理小种的分子检测与鉴定

    Institute of Scientific and Technical Information of China (English)

    莫贱友; 秦碧霞; 郭堂勋; 黄穗萍; 李其利; 李焜华

    2012-01-01

    [目的]明确在广西个别香蕉产区发现的香蕉枯萎病病原种类,为防控该病害提供科学依据.[方法]从广西不同香蕉产区采集香蕉枯萎病病株样本,分离纯化获得6株菌株,以香蕉枯萎病1号和4号生理小种为阳性对照,采用特异PCR的方法,对分离到的6株菌株进行分子检测,并用盆栽香蕉和西贡蕉小苗接种进行菌株致病性鉴定.[结果]经ST1/ST2特异引物扩增,1号菌株与香蕉枯萎病菌1号生理小种扩增到约200 bp片段;2~6号菌株和香蕉枯萎病菌4号生理小种扩增到约250 bp片段.与标样对比结果表明,1号菌株为香蕉枯萎病1号生理小种,2~6号菌株为香蕉枯萎病4号生理小种;盆栽接种致病性鉴定结果与分子检测结果相同.[结论]广西个别蕉区已遭受香蕉枯萎病菌4号小种侵染,各级部门应高度重视.%[Objective]The purpose of the present research was to determine pathogen kinds of banana Fusarium wilt, discovered in some banana growing areas of Guangxi, and to provide scientific references for preventing and controlling banana Fusarium wilt. [Method]Six strains, purified and isolated from banana Fusarium wilt samples collected in different banana growing areas, were detected by specific PCR method; moreover, pot experiment was conducted for pathogenic I-dentification using tissue cultured banana and Xigong banana seedling as test plants. [Result]After ST1/ST2 specific primer amplification, No.1 strain obtained 200 bp segment, which was the same as that of the FOC race 1(positive control), and No. 2 to 6 strains got 250 bp, which was the same result as that of the FOC race 4 (positive control). Compared with the standard specimen, No.l strain was FOC race 1 and the No. 2 to 6 strains were FOC race 4. Therefore the pathogenic identification result of pot inoculation was in accordance with the molecular detection result. [Conclusion]It was testified that FOC race 4 infection had spread in some banana

  18. Testing Some Pedo-Transfer Functions (PTFs in Apulia Region. Evaluation on the Basis of Soil Particle Size Distribution and Organic Matter Content for Estimating Field Capacity and Wilting Point

    Directory of Open Access Journals (Sweden)

    Floriano Buccigrossi

    2010-10-01

    Full Text Available The knowledge of soil water retention vs. soil water matric potential is applied to study irrigation and drainage scheduling, soil water storage capacity (plant available water, solute movement, plant growth and water stress. To measure field capacity and wilting point is expensive, laborious and is time consuming, so, frequently, matemathic models, called pedo-transfer functions (PTFs are utilized to estimate field capacity and wilting point through physical-chemical soil characteristics. Six PTFs have been evaluated (Gupta and Larson, 1979; Rawls et al., 1982; De Jong et al., 1983; Rawls and Brakensiek, 1985; Saxton et al., 1986; Vereecken et al., 1989 by comparing measured soil moisture values with estimated ones at soil water matric potential of -33 and -1500 kPa. Soil samples were collected (361 from 185 pedons of Apulian Region (Southern Italy. Accuracy of the soil moisture predictions is quantified with Root Mean Square Deviation (RMSD between estimated and measured water retention values. In Apulia Region the tested PTFs give different results on soils grouped on the basis of textural composition and organic matter (O.M. content both at the Field Capacity (FC and Wilting Point (WP. At the FC, Gupta and Larson model has given the best performance in Clayey (C, Sandy clay loam (SaCL, Sandy loam (SaL and Silty (Si soil, in loamy and tendency silty soils with O.M. content less than 1.9% and in tendency sandy soils with O.M. content less than 1.5% and greater than 2%; the Rawls model in Silty clay (SiC and Silty loam (SiL soils, in tendency clayey soils with O.M. less than 2.3% and in loamy and tendency silty soils with O.M. greater than 1.9%; the Rawls and Brakensiek model in tendency sandy soils with O.M. content between 1.5 and 2%; the Saxton model in Silty clay loam (SiCL, Loamy sand (LSa soils and in tendency clayey soils with O.M. content greater than 2.3% and the Vereecken model in Sandy clay (SaC, Loamy (L, Clay loam (CL and Sandy (Sa

  19. 感染松萎蔫病的葡萄牙海岸松中内生细菌的分离%Endophytic bacteria isolated from pine wilt-affected Pinus pinaster trees

    Institute of Scientific and Technical Information of China (English)

    Vieira dos Santos M C; Proenca D A N; Fonseca L; Abrantes I M de O; Morais P V

    2011-01-01

    The characteristic rapid death of maritime pine, Pinus pinaster, after infection by the pinewood nematode (PWN), Bursaphelenchus xylophilus, suggests the involvement of other organisms in pine wilt disease (PWD) . Endophytic bacteria are ubiquitous in nature and colonize a broad spectrum of plant species. They colonize plants internally without harming them and although they have been reported to promote plant growth and stimulate plant defence mechanisms. Although such bacteria may be involved in improving plant health, they have also been seen as a potential cause of the low regeneration capacity of mature trees. The bacteria carried out by the PWN throughout pine trees may also contribute to the rapid wilting of the maritime pine trees. This study was made to assess the endophytic microbial community structure of pine wilt affected and non-affected P. pinaster, based on culture isolates, amplified ribosomal DNA restriction analysis (ARDRA) and denaturing gradient gel electrophorosis (DGGE) profiling, and to relate the results to a possible association between the characteristics and bacteria associated with the PWN. The microbial community from trees and PWNs included strains from Beta and Gammaproteobacteria, but Alphaproteobacteria and Bacteroidetes were only found in the endophytic community whereas Actinobacteria and Firmicutes were only found to be associated with the nematode. ARDRA and DGGE profiles showed differences in the diversity of the endophytic microbial community that may be related to the presence of the PWN. Those differences seem to be associated with the number of strains of the genera Burkholderia, Pseudomonas and Luteibacter. Isolates belonging to the species Janthinobacterium agaricidamnosum, P. lutea and Dyella yeojuensis were isolated from trees and were associated with the PWN. This research documents the presence of bacteria associated with the PWN by molecular methods and the impact of the nematode in the plant endophytic microbial

  20. Effects of banana wilt disease on soil nematode community structure and diversity%香蕉枯萎病菌对土壤线虫群落组成及多样性的影响

    Institute of Scientific and Technical Information of China (English)

    钟爽; 何应对; 韩丽娜; 曾会才; 金志强

    2012-01-01

    To investigate the effect of pathogen causing banana wilt disease on soil ecosystem health, the differences of soil nematode trophic groups and ecological indices between banana wilt disease soil and control soil were compared in Hainan Province using soil nematode as bioindicator. The results showed that 31 nematode genera in the disease area and control area were identified, 26 of which was in disease area, 28 in control area. The abundance of total nematodes, bacterivore in 10-30 cm soil layer and plant parasites and the values of Shannon-Wiener diversity index (H') , maturity index (MI) , structure index (SI) and enrichment index (El) were significantly lower (P < 0.01) in the disease area than in the control area, while those of fungivores and Simpson' s dominance index (A) exhibited quite a reverse condition. The abundance of total nematodes and bacterivore decreased (P <0. 01) while those of plant parasites and the values of SI increased (P < 0. 01) with increasing soil depth in the disease area. The abundance of total nematodes and plant parasites decreased (P < 0. 05) and the values of SI (P < 0. 01) increased with increasing soil depth in the control area. It is indicated that pathogen causing banana wilt disease changed soil nematode community structure and decreased diversity of soil nematode community.%为了探明香蕉枯萎病病原菌对土壤生态系统健康水平的影响,利用土壤线虫作为指示生物,对比研究了海南香蕉枯萎病发病蕉园和未发病蕉园土壤线虫营养类群及生态指数之间的差异.结果表明:发病区和对照区共鉴定出土壤线虫属31个,发病区26个,对照区28个;发病区土壤线虫总数、10~30 cm土层食细菌线虫数量、植物寄生线虫数量显著低于对照区(P<0.01),10~20 cm土层食真菌线虫数量显著高于对照区(P<0.01);随着土层深度增加,发病区土壤线虫总数、食细菌线虫数量逐渐降低(P<0.01),植物寄

  1. Água disponível em um Latossolo Vermelho argiloso e murcha fisiológica de culturas Available water in a clayey Oxisol and physiological wilting of crops

    Directory of Open Access Journals (Sweden)

    Vilson A. Klein

    2006-09-01

    Full Text Available Para a determinação do volume de água retido no solo e disponível às plantas, é imprescindível quantificar o teor de água do solo (TAS na capacidade de campo (CC e no ponto de murcha permanente (PMP. O objetivo deste trabalho foi comparar os valores do TAS na CC e no PMP determinados por distintos métodos. Utilizaram-se amostras de um Latossolo Vermelho. A CC foi obtida no campo com o método do perfil instantâneo e, no laboratório, com funis de placa porosa. O PMP foi determinado, em laboratório, como sendo o teor de água residual retida no potencial matricial de -1,5 MPa, em câmara de Richards e com medidor de potencial de ponto de orvalho WP4 PotentiaMeter. Para murcha das plantas, o TAS foi significativamente menor no método fisiológico que o determinado nas câmaras de Richards; entretanto, o teor de água do solo no PMP foi estatisticamente igual para a cultura do girassol e superior para o milho, quando comparado com aquele obtido pelo WP4. A água disponível diminuiu com o aumento na tensão para a estimativa da CC e com o método WP4, mas não diferiu do método fisiológico. Assim, o WP4 permitiu adequada estimativa do PMP e disponibilidade hídrica às plantas, em solo argiloso.To estimate available soil water to plants it is necessary to measure field capacity (FC and permanent wilting point (PWP. The objective of this study was to compare soil moisture at FC and PWP measured by different methods. The soil used was a tropical Oxisol (Haplorthox. The FC was measured under field conditions, using the internal drainage method and in laboratory using porous plate funnel. The PWP was quantified in laboratory as the soil moisture at -1.5 MPa matric potential measured by pressure plate apparatus (Richards chamber and by WP4 dewpoint Potentia Meter. The physiological PWP was measured using corn and sunflower plants, when they had three leaf pairs and showed irreversible wilting. The soil moisture for PWP based on the

  2. The influence of bio-organic fertilizer on banana fusarium wilt and root exudates%生物有机肥对香蕉枯萎病及根系分泌物的影响

    Institute of Scientific and Technical Information of China (English)

    赵兰凤; 胡伟; 刘小锋; 张亮; 李华兴

    2013-01-01

    adjusted community diversity, but the changes of rhizosphere micro-ecology environment depends on the amount and type of root exudates. The influence of bio-organic fertilizer on banana fusarium wilt and root exudates were studied by using in vitro bathing root system under the condition of pot experiment. The results showed that the control effect of banana fusarium wilt by using bio-organic fertilizer were better than organic fertilizer and control treatments,control effect of bio-organic fertilizer and organic fertilizer on banana wilt disease were 55.4%and 28.5%respectively. Oxalic acid, malic acid and fumaric acid were found in organic acid, and organic acid content was dominating of oxalic acid in banana root exudates,the content of oxalic acid was 83.6%-93.0% of organic acid content. In contrast to organic fertilizer treatments, bio-organic fertilizer would reduce malic acid, fumaric acid and organic acid amount in banana root exudates markedly. Organic acids content of different treatment in banana root exudates was:organic fertilizer>bio-organic fertilizer>no fertilizer. The kind and total of amino acid are the most in biological organic fertilizer treatments, followed by the organic fertilizer, and g-ABA, b-Ala, a-ABA, Glu, Asp and P-Ser content in root exudates of biological organic fertilizer treatments are significantly higher than organic fertilizer and no fertilization. Main amino acids (The content of various acids were more than 5%total of amino acid) of biological organic fertilizer treatments have P-Ser, Thr, g-ABA, EOHNH2 and Car, in which P-Ser and g-ABA are significantly higher than organic fertilizer and no fertilization. The index of banana wilt disease was significantly negative correlation with P-Ser, Ser and Ile, the correlation coefficients are-0.99,-0.98 and-0.95 respectively. but it significantly positive correlation with Ans,the correlation coefficients is 1.00. Organic acid amount in banana root exudates was decreased, the kind and total of

  3. Synthetic analogs of bacterial quorum sensors

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Rashi (Los Alamos, NM); Ganguly, Kumkum (Los Alamos, NM); Silks, Louis A. (Los Alamos, NM)

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  4. Liver Cirrhosis and Intestinal Bacterial Translocation

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Intestinal barrier dysfunction, facilitating translocation of bacteria and bacterial products, plays an important role in the pathophysiology of liver cirrhosis and its complications. Intestinal defense system including microbial barrier, immunologic barrier, mechanical barrier, chemical barrier, plays an important role in the maintenance of intestinal function. Under normal circumstances, the intestinal barrier can prevent intestinal bacteria through the intestinal wall from spreading to the body. Severe infection, trauma, shock, cirrhosis, malnutrition, immune suppression conditions, intestinal bacteria and endotoxin translocation, can lead to multiple organ dysfunction. The intestinal microlfora is not only involved in the digestion of nutrients, but also in local immunity, forming a barrier against pathogenic microorganisms. The derangement of the gut microlfora may lead to microbial translocation, deifned as the passage of viable microorganisms or bacterial products from the intestinal lumen to the mesenteric lymph nodes and other extraintestinal sites. In patients with cirrhosis, primary and intestinal lfora imbalance, intestinal bacterial overgrowth, intestinal mucosal barrier dysfunction, endotoxemia is associated with weakened immunity.

  5. Bacterial degradation of monocyclic aromatic amines

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Arora

    2015-08-01

    Full Text Available Aromatic amines are an important group of industrial chemicals, which are widely used for manufacturing of dyes, pesticides, drugs, pigments, and other industrial products. These compounds have been considered highly toxic to human beings due to their carcinogenic nature. Three groups of aromatic amines have been recognized: monocyclic, polycyclic and heterocyclic aromatic amines. Bacterial degradation of several monocyclic aromatic compounds has been studied in a variety of bacteria, which utilizes monocyclic aromatic amines as their sole source of carbon and energy. Several degradation pathways have been proposed and the related enzymes and genes have also been characterized. Many reviews have been reviewed toxicity of monocyclic aromatic amines; however, there is lack of review on biodegradation of monocyclic aromatic amines. The aim of this review is to summarize bacterial degradation of monocyclic aromatic amines. This review will increase our current understanding of biochemical and molecular basis of bacterial degradation of monocyclic aromatic amines.

  6. Mesoscopic modeling of bacterial flagellar microhydrodynamics.

    Science.gov (United States)

    Gebremichael, Yeshitila; Ayton, Gary S; Voth, Gregory A

    2006-11-15

    A particle-based hybrid method of elastic network model and smooth-particle hydrodynamics has been employed to describe the propulsion of bacterial flagella in a viscous hydrodynamic environment. The method explicitly models the two aspects of bacterial propulsion that involve flagellar flexibility and long-range hydrodynamic interaction of low-Reynolds-number flow. The model further incorporates the molecular organization of the flagellar filament at a coarse-grained level in terms of the 11 protofilaments. Each of these protofilaments is represented by a collection of material points that represent the flagellin proteins. A computational model of a single flexible helical segment representing the filament of a bacterial flagellum is presented. The propulsive dynamics and the flow fields generated by the motion of the model filament are examined. The nature of flagellar deformation and the influence of hydrodynamics in determining the shape of deformations are examined based on the helical filament.

  7. Comprehensive characterization of indoor airborne bacterial profile

    Institute of Scientific and Technical Information of China (English)

    P.L.Chan; P.H.F.Yu; Y.W.Cheng; C.Y.Chan; P.K.Wong

    2009-01-01

    This is the first detailed characterization of the air-borne bacterial profiles in indoor environments and two restaurants were selected for this study.Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter?.The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant species.Most bacteria identified were representative species of skin and respiratory tract of human, and soil.Although the bacterial levels in these restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens.These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.

  8. Citrobacter rodentium mouse model of bacterial infection.

    Science.gov (United States)

    Crepin, Valerie F; Collins, James W; Habibzay, Maryam; Frankel, Gad

    2016-10-01

    Infection of mice with Citrobacter rodentium is a robust model to study bacterial pathogenesis, mucosal immunology, the health benefits of probiotics and the role of the microbiota during infection. C. rodentium was first isolated by Barthold from an outbreak of mouse diarrhea in Yale University in 1972 and was 'rediscovered' by Falkow and Schauer in 1993. Since then the use of the model has proliferated, and it is now the gold standard for studying virulence of the closely related human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Here we provide a detailed protocol for various applications of the model, including bacterial growth, site-directed mutagenesis, mouse inoculation (from cultured cells and after cohabitation), monitoring of bacterial colonization, tissue extraction and analysis, immune responses, probiotic treatment and microbiota analysis. The main protocol, from mouse infection to clearance and analysis of tissues and host responses, takes ∼5 weeks to complete.

  9. A preliminary report of the new strategy on eradicating epidemic pine wilt disease and its application effects in a pine forest%防治松萎蔫病的新策略及林间防效初报

    Institute of Scientific and Technical Information of China (English)

    赵博光; 王石发; 张志超; 曲花荣; 逄焕臣; 宋绍义

    2012-01-01

    On the basis of the new theory, namely that the pine wilt disease is a complex one induced by the pine wood nematode and its associated pathogenic bacteria, and that the special pattern of pine wilt disease in a forest belongs to aggregated distribution, we suggest a new strategy, that is to treat all of the host trees by trunk injecting of the new nematicide, a -terthienyl and a bactericide, oxolinic acid, within the area bounded by a circle of Som radius and the concentration point of the dead trees as the center of the circle. The new strategy had been used in a 20hm2 forest of Pinus thunbergii during 2010 to 2011. Up to now there has not been any dead tree found in the treated area in contrast to 24 dead ones in the control area. The test in the forest is continuing and new results will be followed.%在松萎蔫病是由松材线虫与其携带的致病细菌诱导的一种复合侵染病害的新学说的指导下,根据松萎蔫病在疫区病树呈聚集分布,提出了防治松萎蔫病的新策略,即利用我们研究开发防治松萎蔫病的新药剂α-三噻吩与杀细菌剂恶喹酸对在以病死树中心周围半径50 m的范围内所有寄主树进行注干处理.经过2010-2011年在面积近20 hm2的处理黑松林地的防治试验,至2011年12月已经取得了良好的防效.处理林地中没有再发生病死树,对照区内却有24株病死树.防治仍在继续,新结果将继续报道.

  10. Qualidade da silagem de capim-elefante (Pennisetum purpureum Schum. emurchecido ou acrescido de farelo de mandioca Quality of elephantgrass silage (Pennisetum purpureum Schum. wilted or adding cassava meal

    Directory of Open Access Journals (Sweden)

    Evaldo Ferrari Júnior

    2001-10-01

    Full Text Available Realizou-se um experimento para avaliar a silagem de capim-elefante cv. Taiwan A-146, submetida a seis tratamentos e quatro repetições: A - capim-elefante emurchecido ao sol por 8 horas; B - capim-elefante sem emurchecimento; C - capim-elefante (98% mais farelo de mandioca (2%; D - capim-elefante (96% mais farelo de mandioca (4%; E - capim-elefante (92% mais farelo de mandioca (8% e F - capim-elefante (88% mais farelo de mandioca (12%. A adição de 12% de farelo de mandioca mostrou-se mais eficiente que o emurchecimento em aumentar o teor de matéria seca da silagem. A adição de farelo de mandioca promoveu decréscimo no teor de proteína bruta, matéria orgânica, fibra em detergente neutro e hemicelulose de forma linear, porém aumentou os teores de extrativo não nitrogenado, matéria mineral e carboidratos solúveis das silagens. Os teores de ácido lático mostraram-se baixos, indicando que o farelo de mandioca não foi utilizado de forma eficiente pelos lactobacilos. Não foram observadas diferenças significativas entre as porcentagens dos ácidos acético, propiônico, butírico e lático nas silagens. O emurchecimento e a adição de farelo de mandioca podem ser utilizados como alternativas para aumentar o teor de matéria seca da silagem.Silage evaluation of elephantgrass cv. Taiwan A146 was done at Faculdade de Medicina Veterinária e Zootecnia - UNESP-Botucatu. Six treatments were used with four replications as follows: A - elephantgrass with eight hours of wilting under the sun; B - elephantgrass; C - elephantgrass (98% plus cassava meal (2%; D - elephantgrass (96% plus cassava meal (4%; E - elephantgrass (92% plus cassava meal (8%; F - elephantgrass (88% plus cassava meal (12%. The efficiency meal (12% was greater than wilting in increasing total dry matter content. The addition of cassava led to a linear decrease in CP, OM, NDF and hemicellulose content, at the same time it increased the NFE, ASH and soluble carbohidrates

  11. 有机肥与生防菌结合防治香蕉枯萎病的初步研究%Effects of applying techniques of organic fertilizer on growth and field controlling Fusarium wilt disease of banana

    Institute of Scientific and Technical Information of China (English)

    李国良; 姚丽贤; 杨苞梅; 何兆桓; 周昌敏; 涂仕华

    2012-01-01

    研究在适宜化肥用量条件下配施有机肥与生防菌、土壤消毒与生防菌对香蕉植株生长和香蕉枯萎病防治效果的影响.结果表明,两个配施鸡粪处理分别在香蕉营养生长期和抽蕾期蕉株最高,茎围最大.鸡粪淋施复合芽孢杆菌处理成熟蕉果可溶性糖含量与Vc含量最高,产量最高,比氮磷钾处理增产8.9%;在种植后5个月才开始发病,发病时间延缓,发病后病况稳定且发病率最低,为17.8%,比其它处理降低6.6 ~46.6个百分点,防治效果最好.受香蕉收获株数减少、种植成本上涨、香蕉价格不稳定等因素影响,建议在已发枯萎病蕉园种植其它作物以获得更高种植效益.%A field experiment was carried out to investigate effects of the suitable amount of chemical fertilizer applying or-angic fertilizer and biocontrol bacteria, soil disinfection and biocontrol bacteria on banana plant growth and the suppression on the banana Fusarium wilt. The results were as follows: banana plant height was the highest and the pseudostem diameter was the widest at the vegetative growth period and bug period by applying chicken manure. Soluble sugar, vitamin C contents and the yield increased by 8. 9% than CK treatment were the highest in chicken manure and complex Bacillus sp agent treatment. Banana Fusarium wilt time was postponed after five months planted. Disease incidence was stability and lower by 6. 6 to 46. 6 percentage point than other treatments. The control efficiency was best. It was suggestted that other crops were planted on the current disease orchards in order to gain the better plantation profits under the influence of less plant population, rising planted cost, instable price and so on.

  12. 香蕉枯萎病抗性品种及绿色药剂的初步筛选%Preliminary screening of cultivars and green fungicides against banana Fusarium wilt

    Institute of Scientific and Technical Information of China (English)

    杨静美; 冯岩; 林铭欢; 伍惠媚; 黄秉智; 许林兵

    2014-01-01

    为筛选抗枯萎病香蕉品种,通过伤根、针刺及淋菌法接种香蕉枯萎病菌4号小种,进行盆栽试验,结果表明,品种‘巴西蕉’和‘南天红’的病情指数较高,分别达42.5和37.5,为中感品种;而品种‘南天青’和‘南天黄’病情指数仅为15,为抗病品种;‘农科一号’病情指数最低,仅为7.5,是5个品种中最抗病的,为高抗品种。为筛选防治香蕉枯萎病的绿色药剂,选用壳聚糖水剂、竹醋液、耕保泰对比络氨铜水剂对‘巴西蕉’进行盆栽药效试验,结果表明,耕保泰防治效果较好,相对防效达78.57%;20%竹醋液的防治效果最差,仅为35.71%。%In order to select cultivars against banana Fusarium wilt,pot experiments were carried out with the in-oculation methods of root cutting,prodding and sprinkling fungus of Fusarium oxysporum f.sp.cubense Race 4. The results showed that after inoculated with Fusarium ,the disease indexes of ‘Brazil banana’and ‘Skyred ba-nana’were 42.5 and 37.5,respectively,indicating they were middle susceptible.While the disease index of‘Skygreen’was 15,the same as ‘Skyyellow’,indicating they were the resistant cultivars.‘Agricultural one’dem-onstrated the lowest disease index of all the cultivars,only 7.5,which was the high resistant cultivar.Green fungicides against banana Fusarium wilt were also screened by pot experiments with chitosan,bamboo vinegar,Gengbaotai,com-pared with cuaminosulfate.The pot experiment with fungicides on ‘Brazil banana’showed that Gengbaotai had the best control effiacy by 78.57%.However,20% of bamboo vinegar was the weakest with the efficacy of 35.71%.

  13. 抗松材线虫病赤松组培苗的抗病性测定1)%Resistance Determination of Wilt-resistant Pinus densiflora Tissue Culture Seedling to Bursaphelenchus xylophilus

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    An experiment was conducted to determine the resistance of wilt-resistant Pinus densiflora to Bursaphelenchus xylophi-lus from Japan.Six months old tissue culture seedlings of Pinus densiflora were inoculated with middle virulence aseptic pine wood nematode under aseptic conditions.There are obvious differences of resistance in Pinus densiflora families.No.1 and 10 families have better resistant effects, followed by No.2, 13, 19, 22 and 23 families.The resistance difference of clones mainly originates from the families.Meanwhile, the relationship between pine wood nematode breeding rates and disease incidence was discussed.There is a low correlation between the disease incidence of wilt-resistant Pinus densiflora and pine wood nematode propagation coefficient.In addition, the susceptible tissue culture seedlings were isolated.The pine wood nematode remains aseptic.%  为了评价从日本引进的抗性赤松对松材线虫的抗病性,在无菌条件下,用中强毒力无菌松材线虫对6个月生的无菌赤松组培苗进行接种。结果表明:抗性赤松不同家系间抗病性差异明显,1号和10号家系抗病性表现较好,2、13、19、22和23号家系抗病性表现次之,3、14和16号家系未表现出抗病性;抗性赤松不同无性系间的抗病性存在极显著差异,无性系间的抗病性差异主要来源于家系间的抗病性差异。发病率与松材线虫繁殖倍数相关性极低。从发病组培苗上分离的松材线虫仍然无菌。

  14. Growth performance on regenerated plantlets of Pinus densiflora resistance to pine wilt disease%抗松材线虫病赤松组培再生植株田间生长表现

    Institute of Scientific and Technical Information of China (English)

    秦莉; 吴小芹; 朱丽华; 叶建仁; 张红岩

    2011-01-01

    In order to evaluate the performance of regenerated plantlets of Pinus densiflora resistance to pine wilt disease,research has advanced to the field testing stage. The results showed that 0.5 year-old plantlets survival rate was apparently lower than that of 2.5,2,1.5,1 year-old. There were obvious growth difference among different clones. Mycorrhizal foresting test indicated that ectomycorrhizal fungi Rhizopogen luteous and Boletus edulis facilitated the growth of disease-resistant P. densiflora 1 # -A 5 and 8 generation. This research provided reference for breeding and afforestation of regenerated plantlets of P. densiflora resistance to pine wilt disease.%为了评价从日本引进的抗松材线虫病赤松通过无性快繁获得的再生植株在我国的生长状况.本研究对田间试种的抗病赤松6个家系12个无性系共688株再生植株进行跟踪监测.结果表明,抗病赤松0.5年生再生植株试种成活率明显低于2.5年、2年、1.5年及1年生再生植株;不同无性系间抗病赤松再生植株生长状况存在明显差异.其中,1#-A和5#-5无性系再生植株生长较好.菌根化造林试验表明,两种外生菌根菌美味牛肝菌(Be)和黄色须腹菌(R1)对抗病赤松1#-A5代、8代再生植株具有明显促生效果.此研究为今后抗病赤松再生植株造林育种提供了参考依据.

  15. Isolation and Identification of Plantain (Musa paradisiaca Linn.) Fusarium Wilt Disease Pathogen and Pathogenicity Test%大蕉枯萎病病原菌的分离、鉴定和致病性测定

    Institute of Scientific and Technical Information of China (English)

    郭立佳; 彭军; 杨腊英; 王国芬; 梁昌聪; 刘磊; 黄俊生

    2013-01-01

    从表现枯萎病症状的大蕉球茎病组织中获得10株分离物,采用形态学分类方法将这些分离物鉴定为尖孢镰刀菌.利用分离物DJ1的rDNA-ITS区序列和IGS序列开展的系统发育分析迸一步确定DJ1为尖孢镰刀菌.对不同香蕉品系的致病性测定结果表明,DJ1对粉蕉(Musa sp.ABB)的致病性最强,其次是特威(Musa sp.AAA)、巴西蕉(Musa sp.AAA)和泰蕉(Musa sp.AAA),对皇帝蕉(Musa sp.AA)的致病性较弱,根据DJ1的寄主范围确定DJ1为尖孢镰刀菌古巴专化型生理4号小种.对IGS序列的进一步比对分析表明DJ1不属于热带4号生理小种菌株.这些结果为大蕉枯萎病的防治提供了重要依据和指导.%Plantain (Musa paradisiaca linn.) is an edible banana, and the causal agent of plantain wilt disease hasn't been reported until now. In this study, ten isolates (DJ1-10) from the conns of the plantains that showed wilt symptoms were isolated. These isolates were preliminarily identified as Fusarium oxysporm based on their morphological characteristics. Then phylogenetic analysis based on the sequences of rDNA-ITS and intergenic spacer (IGS) regions added proof that the isolate DJ1 was F. oxysporum. The pathogenicity assays showed that DJ1 was able to infect 5 varieties of the genus Musa including Fenjiao (Musa sp. ABB), Hangdijiao (Musa sp. AA), Taijiao (Musa sp. AAA), Tewei (Musa sp. AAA) and Brazilian (Musa sp. AAA), but it was most pathogenic to Fenjiao, then Tewei, Taijiao and Bazilian, and it was less pathogenic to Huangdijiao. These results imply that DJ1 might be an isolate from race 4 of Fusarium oxysporum f. sp. cubense (Foe).

  16. Value of a newly sequenced bacterial genome

    DEFF Research Database (Denmark)

    Barbosa, Eudes; Aburjaile, Flavia F; Ramos, Rommel Tj;

    2014-01-01

    Next-generation sequencing (NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also...... in an exponential increase in draft (partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome...

  17. Neurosonographic findings of bacterial meningitis in Infants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Chul; Lee, Sung Sik; Lee, Hong Kue; Lee, Soon Il [Sowa Children' s Hospital, Seoul (Korea, Republic of)

    1989-02-15

    44 infants under 1 year were studied retrospectively during these illness and follow up after 1 week intervals. The spectrum of sonographic features of bacterial meningitis in acute stage included normal scan (20 patients), echogenic sulci (10 patients), echogenic lining of epandymas (8 patients), Abnormal parenchymal echogenecity (6 patients). On follow up examination with 1 week intervals, variety of complications was found in 14 patients (32%) of the infants. There were ventriculomegaly in 7 patients, extraaxial fluid collection in 4 patients, brain abscess in 2 patients and poor encephalic cyst in 1 patient. We conclude that ultrasound was an effective method for evaluation of progression and complications of bacterial meningitis.

  18. CT scan of bacterial and aseptic meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Saiwai, Shigeo; Tamaoka, Koichi (Kobe Central Municipal Hospital (Japan))

    1983-01-01

    CT scans of the patients with aseptic and bacterial meningitis were reviewed and compared to previous reports. In aseptic meningitis, no abnormal CT findings were observed. In bacterial meningitis, CT findings were ventricular dilatation, subdural fluid collection, parenchymal low density, intracerebral hematoma and meningeal enhancement after contrast injection. Three patients among 48 suffered from status epileptics during the course of the illness. All of the 3 patients developed parenchymal inhomogeneous low density and progressive ventricular dilatation which did not improve after ventricular peritoneal shunt surgery. We believe that these changes are most likely due to hypoxic hypoxemia during epileptic seizure and meningitis itself seems to play a little role.

  19. Horizontal gene transfer and bacterial diversity

    Indian Academy of Sciences (India)

    Chitra Dutta; Archana Pan

    2002-02-01

    Bacterial genomes are extremely dynamic and mosaic in nature. A substantial amount of genetic information is inserted into or deleted from such genomes through the process of horizontal transfer. Through the introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological and pathogenic character of bacterial species and thereby promotes microbial diversification and speciation. This review discusses how the recent influx of complete chromosomal sequences of various microorganisms has allowed for a quantitative assessment of the scope, rate and impact of horizontally transmitted information on microbial evolution.

  20. Glucocorticosteroids: as Adjuvant Therapy for Bacterial Infections

    Directory of Open Access Journals (Sweden)

    WONDIM MELKAM

    2015-01-01

    Full Text Available Glucocorticoids (GCs, synthetic analogues of the natural steroid hormones, are well known for their antiinflammatory and immunosuppressive properties in the periphery. They are widely and successfully used in the treatment of autoimmune diseases, chronic inflammation, and transplant rejection. Nowadays, GCs are claimed to have a beneficial role being as adjunct therapy in various infections. Different studies have been conducted to investigate their use as adjuvant therapy for different bacterial infection. This review, therefore, summarizes various bacterial infections for which glucocorticoids are reported to be used as adjuvant therapy, strategies for administration of glucocorticoids, and challenges of using glucocorticoids as adjuvant therapy.