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Sample records for bacterial leaf spot

  1. Bacterial Leaf Spot of Parsley: Characterization of a New Disease

    Science.gov (United States)

    Since 2002, a severe leaf spot disease on parsley has occurred throughout central coastal California and particularly in Monterey County. Two different bacterial pathogens (Pseudomonas syringae pv. apii, and P. syringae pv. coriandricola) have been associated these outbreaks on parsley. Our research...

  2. Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians

    Science.gov (United States)

    Baby leaf lettuce cultivars with resistance to bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vitians (Xcv) are needed to reduce crop losses. The objectives of this research were to assess the genetic diversity for BLS resistance in baby leaf lettuce cultivars and to select early gen...

  3. Bacterial brown leaf spot of citrus, a new disease caused by Burkholderia andropogonis

    Science.gov (United States)

    A new bacterial disease of citrus was recently identified in Florida and named as bacterial brown leaf spot (BBLS) of citrus. BBLS-infected citrus displayed flat, circular and brownish lesions with water-soaked margins surrounded by a chlorotic halo on leaves. Based on Biolog carbon source metabolic...

  4. Show us your spots! Researchers need samples of bacterial leaf spots on celery, cilantro, parsley, and other crops.

    Science.gov (United States)

    Since 2002, a severe leaf spot disease on parsley has occurred throughout central coastal California and particularly in Monterey County. Three different bacterial pathogens (Pseudomonas syringae pv. apii, P. syringae pv. coriandricola and an organism very closely related to P. viridiflava) have bee...

  5. The inheritance of resistance to bacterial leaf spot of lettuce caused by Xanthomonas campestris pv. vitians in three lettuce cultivars

    Science.gov (United States)

    Lettuce yields can be reduced by the disease bacterial leaf spot (BLS) caused by the pathogen Xanthomonas campestris pv. vitians (Xcv) and host resistance is the most feasible method to reduce disease losses. The cultivars La Brillante, Pavane, and Little Gem express an incompatible host-pathogen in...

  6. Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

    Directory of Open Access Journals (Sweden)

    Da-Ran Kim

    2016-08-01

    Full Text Available Strawberry bacterial angular leaf spot (ALS disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August, the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%. To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.

  7. Evaluation of indigenous bacterial strains for biocontrol of the frogeye leaf spot of soya bean caused by Cercospora sojina.

    Science.gov (United States)

    Simonetti, E; Carmona, M A; Scandiani, M M; García, A F; Luque, A G; Correa, O S; Balestrasse, K B

    2012-08-01

    Assessment of biological control of Cercospora sojina, causal agent of frogeye leaf spot (FLS) of soya bean, using three indigenous bacterial strains, BNM297 (Pseudomonas fluorescens), BNM340 and BNM122 (Bacillus amyloliquefaciens). From cultures of each bacterial strain, cell suspensions and cell-free supernatants were obtained and assayed to determine their antifungal activity against C. sojina. Both mycelial growth and spore germination in vitro were more strongly inhibited by bacterial cell suspensions than by cell-free supernatants. The Bacillus strains BNM122 and BNM340 inhibited the fungal growth to a similar degree (I ≈ 52-53%), while cells from P. fluorescens BNM297 caused a lesser reduction (I ≈ 32-34%) in the fungus colony diameter. The foliar application of the two Bacillus strains on soya bean seedlings, under greenhouse conditions, significantly reduced the disease severity with respect to control soya bean seedlings and those sprayed with BNM297. This last bacterial strain was not effective in controlling FLS in vivo. Our data demonstrate that the application of antagonistic bacteria may be a promising and environmentally friendly alternative to control the FLS of soya bean.   To our knowledge, this is the first report of biological control of C. sojina by using native Bacillus strains. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

  8. Association analysis of bacterial leaf spot resistance and SNP markers derived from expressed sequence tags (ESTs) in lettuce (Lactuca sativa L.)

    Science.gov (United States)

    Bacterial leaf spot of lettuce, caused by Xanthomonas campestris pv. vitians, is a devastating disease of lettuce worldwide. Since there are no chemicals available for effective control of the disease, host-plant resistance is highly desirable to protect lettuce production. A total of 179 lettuce ge...

  9. Association Mapping of Quantitative Trait Loci in Spring Wheat Landraces Conferring Resistance to Bacterial Leaf Streak and Spot Blotch

    Directory of Open Access Journals (Sweden)

    Tika B. Adhikari

    2012-03-01

    Full Text Available Bacterial leaf streak (BLS, caused by pv. (Smith et al. Bragard et al., and spot blotch (SB, caused by (S. Ito & Kurib. Drechs. ex Dastur, are two emerging diseases of wheat ( L.. To achieve sustainable disease management strategies and reduce yield losses, identifying new genes that confer quantitative resistance would benefit resistance breeding efforts. The main objective of this study was to use association mapping (AM with 832 polymorphic Diversity Arrays Technology (DArT markers to identify genomic regions associated with resistance to BLS and SB in 566 spring wheat landraces. From data analysis of this diverse panel of wheat accessions, we discovered five novel genomic regions significantly associated with resistance to BLS on chromosomes 1A, 4A, 4B, 6B, and 7D. Similarly, four genomic regions were found to be associated with resistance to SB on chromosomes 1A, 3B, 7B, and 7D. A high degree of linkage disequilibrium (LD decayed over short genetic distance in the set of wheat accessions studied, and some of these genomic regions appear to be involved in multiple disease resistance (MDR. These results suggest that the AM approach provides a platform for discovery of resistance conditioned by multiple genes with quantitative effects, which could be validated and deployed in wheat breeding programs.

  10. Construction and characterization of a bacterial artificial chromosome library of the causal agent of Black Sigatoka fungal leaf spot disease of banana and plantain, Mycosphaerella fijiensis.

    Science.gov (United States)

    Canto-Canché, Blondy; Guillén-Maldonado, Diana Karina; Peraza-Echeverría, Leticia; Conde-Ferráez, Laura; James-Kay, Andrew

    2007-05-01

    A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain, Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes. After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector). One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9 x genome equivalents, which was supported by hybridization results with homologous and heterologous probes.

  11. A Risk Assessment Model for Bacterial Leaf Spot of Pepper (Capsicum annuum), Caused by Xanthomonas euvesicatoria, Based on Concentrations of Macronutrients, Micronutrients, and Micronutrient Ratios.

    Science.gov (United States)

    Dutta, B; Langston, D B; Luo, X; Carlson, S; Kichler, J; Gitaitis, R

    2017-11-01

    The phytopathogenic bacterium Xanthomonas euvesicatoria causes bacterial leaf spot (BLS) of pepper and has a worldwide distribution. BLS is difficult to control and an integrated management strategy that incorporates crop rotation, use of clean seed and clean plants, weed control, resistant varieties, applications of bactericides, biocontrol agents, and systemic acquired resistance (SAR) inducers is generally recommended. However, even with that arsenal of weapons, BLS can still be responsible for severe losses under favorable environmental conditions. Thus, additional tools need to be added to an overall integrated management strategy to combat BLS. In this article, we developed several models from 2012 to 2014 that were based on how macronutrients, micronutrients, and micronutrient ratios affect BLS severity. Factors used to select a model for validation included highly significant P values, high adjusted R 2 values, low variance inflation factor values (macronutrient and micronutrient concentrations affect plant disease resistance genes in the SAR pathway.

  12. Resistance in winter barley against Ramularia leaf spot

    DEFF Research Database (Denmark)

    Hjortshøj, Rasmus Lund

    Ramularia leaf spot is an emerging disease in barley caused by R. collo-cygni. At present little is known about the resistance mechanisms carried out by the host plant to avoid disease development. Nor is the lifecycle of the fungus or its populations structure fully understood. To gain insight....... fulvum-tomato and S. tritici-wheat in order to find modelsystems to enhance interpretation of results from R. collo-cygni-barley interaction. Results from the mapping showed that resistance to Ramularia leaf spot is controlled by a number of QTL’s, some of which co-locate with other physiological traits....... The populations further segregated for physiological leaf spots, a phenomenon related to the leaf damage imposed by Rubellin, although, resistance to physiological leafspots appeared to come from the Ramularia leaf spot susceptible parent. The toxin assay further supported this result as the genotypes susceptible...

  13. Genetic characterization of angular leaf spot resistance in selected ...

    African Journals Online (AJOL)

    Mr Tryphone

    2015-10-28

    Oct 28, 2015 ... Angular leaf spot disease (ALS) caused by Pseudocercospora griseola is one ... Author(s) agree that this article remains permanently open access under the terms ... that results in shrivelled seeds of reduced size and quality.

  14. prevalence of angular leaf spot disease and sources of resistance

    African Journals Online (AJOL)

    USER

    2017-02-17

    Feb 17, 2017 ... Angular leaf spot (Pseudocercospora griseola Crous U, Brown) is one of the ..... Incidence of six foliar bean diseases in two agro ecological zones of eastern Democratic Republic of .... use of poor quality farmer-saved seed.

  15. Developing markers for Sigatoka leaf spot disease (Mycosphaerella ...

    African Journals Online (AJOL)

    Jane

    2011-07-06

    Jul 6, 2011 ... Developing markers for Sigatoka leaf spot disease ... OPERON primer pairs were used to screen genomic DNA from two resistant cultivars: Calcutta 4 ( ..... Blomme G, Eden-Green S, Mustaffa M, Nwauzoma B, Thangavelu R.

  16. Sugarbeet leaf spot disease (Cercospora beticola Sacc.)dagger.

    Science.gov (United States)

    Weiland, John; Koch, Georg

    2004-05-01

    SUMMARY Leaf spot disease caused by Cercospora beticola Sacc. is the most destructive foliar pathogen of sugarbeet worldwide. In addition to reducing yield and quality of sugarbeet, the control of leaf spot disease by extensive fungicide application incurs added costs to producers and repeatedly has selected for fungicide-tolerant C. beticola strains. The genetics and biochemistry of virulence have been examined less for C. beticola as compared with the related fungi C. nicotianae, C. kikuchii and C. zeae-maydis, fungi to which the physiology of C. beticola is often compared. C. beticola populations generally are not characterized as having race structure, although a case of race-specific resistance in sugarbeet to C. beticola has been reported. Resistance currently implemented in the field is quantitatively inherited and exhibits low to medium heritability. Cercospora beticola Sacc.; Kingdom Fungi, Subdivision Deuteromycetes, Class Hyphomycetes, Order Hyphales, Genus Cercospora. Circular, brown to red delimited spots with ashen-grey centre, 0.5-6 mm diameter; dark brown to black stromata against grey background; pale brown unbranched sparingly septate conidiophores, hyaline acicular conidia, multiseptate, from 2.5 to 4 microm wide and 50-200 microm long. Propagative on Beta vulgaris and most species of Beta. Reported on members of the Chenopodiaceae and on Amaranthus. Disease symptoms: Infected leaves and petioles of B. vulgaris exhibit numerous circular leaf spots that coalesce in severe cases causing complete leaf collapse. Dark specks within a grey spot centre are characteristic for the disease. Older leaves exhibit a greater number of lesions with larger spot diameter. During the latter stage of severe epiphytotics, new leaf growth can be seen emerging from the plant surrounded by prostrate, collapsed leaves. Fungicides in the benzimidazole and triazole class as well as organotin derivatives and strobilurins have successfully been used to control Cercospora

  17. Alternaria leaf spot in Michigan and fungicide sensitivity issues

    Science.gov (United States)

    Since 2010 there has been an increase in identification of Alternaria leaf spot on sugar beet in Michigan and other growing regions in the US and Canada. In 2016, the disease was severe enough to cause economic losses in the Michigan growing region. Michigan isolates from sugar beet were examined ...

  18. Species of Cercospora associated with grey leaf spot of maize

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Groenewald, M.; Caldwell, P.; Braun, U.; Harrington, T.C.

    2006-01-01

    Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. The causal organism associated with the disease is Cercospora zeae-maydis. Two potential sibling species have been recognized as Groups I and II. The DNA sequences for the

  19. Species of Cercospora associated with grey leaf spot of maize.

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Groenewald, M.; Caldwell, P.; Braun, U.; Harrington, T.C.

    2006-01-01

    Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. The causal organism associated with the disease is Cercospora zeae-maydis. Two potential sibling species have been recognized as Groups I and II. The DNA sequences for the

  20. Effects of Variety and Fungicidal Rate on Cercospora Leaf Spots ...

    African Journals Online (AJOL)

    Singh, V.R., Pandes, A.K., Reddy, P.M. and. Pao P.V. (1995). Resistance to Rust and Late leaf Spot of Groundnut. ICRISAT. Information Bulletin. No.47, Patancheru,. 502, 324, Andra Pradesh, India. P.24. Thapar, S., Bhusham, R. and Mathur, R.P.. (1995). Degradation of organophosphorus and carbamate pesticides in soils- ...

  1. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Luseko

    2013-07-03

    Jul 3, 2013 ... Angular leaf spot (ALS) caused by the fungus Pseudocercospora griseola and Bean common mosaic and necrosis virus (BCMV/BCMNV) are important diseases of common bean in Tanzania that can cause severe yield reduction when uncontrolled. This study was conducted to incorporate resistant genes ...

  2. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Angular leaf spot (ALS) caused by the fungus Pseudocercospora griseola and Bean common mosaic and necrosis virus (BCMV/BCMNV) are important diseases of common bean in Tanzania that can cause severe yield reduction when uncontrolled. This study was conducted to incorporate resistant genes for ALS and ...

  3. Foliar Application of the Fungicide Pyraclostrobin Reduced Bacterial Spot Disease of Pepper

    Directory of Open Access Journals (Sweden)

    Beom Ryong Kang

    2018-03-01

    Full Text Available Pyraclostrobin is a broad-spectrum fungicide that inhibits mitochondrial respiration. However, it may also induce systemic resistance effective against bacterial and viral diseases. In this study, we evaluated whether pyraclostrobin enhanced resistance against the bacterial spot pathogen, Xanthomonas euvesicatora on pepper (Capsicum annuum. Although pyraclostrobin alone did not suppressed the in vitro growth of X. euvesicatoria, disease severity in pepper was significantly lower by 69% after treatments with pyraclostrobin alone. A combination of pyraclostrobin with streptomycin reduced disease by over 90% that of the control plants. The preventive control of the pyraclostrobin against bacterial spot was required application 1-3 days before pathogen inoculation. Our findings suggest that the fungicide pyraclostrobin can be used with a chemical pesticide to control bacterial leaf spot diseases in pepper.

  4. Resistência genética à mancha-bacteriana em genótipos de pimentão Genetic resistance to bacterial leaf spot on sweet pepper genotypes

    Directory of Open Access Journals (Sweden)

    Roberto Alexandre Costa

    2002-03-01

    Full Text Available A mancha-bacteriana, principal doença bacteriana do pimentão causa desfolha intensa quando em condições favoráveis, deixando os frutos expostos ao sol, depreciando-os e diminuindo a produção. Para estimar, nas condições de Campos dos Goytacazes, os efeitos genéticos da reação do hospedeiro ao patógeno, tanto em folhas como em frutos, foram obtidos híbridos F1, sem recíprocos, a partir de cruzamentos dialélicos entre cinco genótipos de pimentão, sendo três suscetíveis ('UENF 1420', 'UENF 1421' e 'UENF 1422' e dois resistentes ('UENF 1381' e 'UENF 1382'. A inoculação com Xanthomonas campestris pv. vesicatoria constou de infiltração no mesófilo foliar, utilizando-se a concentração de 10³ células/ml, ajustada com auxílio de espectrofotômetro. Os efeitos de variedade e de heterose média foram significativos para resistência em folhas, indicando que efeitos aditivos e de dominância estão envolvidos no controle genético deste caráter. Para resistência em frutos, apenas os efeitos de variedade foram significativos, indicando a presença de efeitos aditivos no controle desta característica. A partir das análises puderam ser selecionados os parentais para RMB em folhas: 'UENF 1381' e 'UENF 1382'. Para RMB em frutos 'UENF 1381' e 'UENF 1421' foram os melhores parentais. Os melhores híbridos para RMB em folhas foram: 'UENF 1420' x 'UENF 1421', 'UENF 1382' x 'UENF 1420', 'UENF 1381' x 'UENF 1420', 'UENF 1381' x 'UENF 1421', 'UENF 1381' x 'UENF 1422' e 'UENF 1381' x 'UENF 1382'.Bacterial leaf spot (BLS is the most important bacterial disease in sweet pepper, causing intense defoliation under favorable conditions, leaving the exposed fruits to sunburn and decreasing the yield. To estimate genetic effects of the reaction to BLS on leaves and fruits, under the conditions of Campos dos Goytacazes (Brazil, hybrids F1, without reciprocals, were obtained from diallel crosses among five pepper genotypes, three susceptible

  5. Multilocus sequence typing of Pseudomonas syringae sensu lato confirms previously described genomospecies and permits rapid identification of P. syringae pv. coriandricola and P. syringae pv. apii causing bacterial leaf spot on parsley.

    Science.gov (United States)

    Bull, Carolee T; Clarke, Christopher R; Cai, Rongman; Vinatzer, Boris A; Jardini, Teresa M; Koike, Steven T

    2011-07-01

    Since 2002, severe leaf spotting on parsley (Petroselinum crispum) has occurred in Monterey County, CA. Either of two different pathovars of Pseudomonas syringae sensu lato were isolated from diseased leaves from eight distinct outbreaks and once from the same outbreak. Fragment analysis of DNA amplified between repetitive sequence polymerase chain reaction; 16S rDNA sequence analysis; and biochemical, physiological, and host range tests identified the pathogens as Pseudomonas syringae pv. apii and P. syringae pv. coriandricola. Koch's postulates were completed for the isolates from parsley, and host range tests with parsley isolates and pathotype strains demonstrated that P. syringae pv. apii and P. syringae pv. coriandricola cause leaf spot diseases on parsley, celery, and coriander or cilantro. In a multilocus sequence typing (MLST) approach, four housekeeping gene fragments were sequenced from 10 strains isolated from parsley and 56 pathotype strains of P. syringae. Allele sequences were uploaded to the Plant-Associated Microbes Database and a phylogenetic tree was built based on concatenated sequences. Tree topology directly corresponded to P. syringae genomospecies and P. syringae pv. apii was allocated appropriately to genomospecies 3. This is the first demonstration that MLST can accurately allocate new pathogens directly to P. syringae sensu lato genomospecies. According to MLST, P. syringae pv. coriandricola is a member of genomospecies 9, P. cannabina. In a blind test, both P. syringae pv. coriandricola and P. syringae pv. apii isolates from parsley were correctly identified to pathovar. In both cases, MLST described diversity within each pathovar that was previously unknown.

  6. Determination of Economic Control Thresholds for Bacterial Spot on Red Pepper Caused by Xanthomonas campestris pv. vesicatoria

    Directory of Open Access Journals (Sweden)

    Ju-Hee Kim

    2015-06-01

    Full Text Available This study was carried out to develop the economic thresholds for the control of bacterial spot of red pepper. The correlation between diseased leaf rate and yield in field was Y = -0.724X + 281.58, R² = 0.78, r = -0.88**. The correlation between diseased leaf rate and yield loss in field was Y = 0.813X + 15.95, R² = 0.78, r = 0.88*. We found that control thresholds was below 30.3% diseased leaves rate per plant in field. The economic control thresholds for bacterial spot of red pepper was below 16.3%.

  7. Inhibition of Xanthomonas fragariae, Causative Agent of Angular Leaf Spot of Strawberry, through Iron Deprivation

    Directory of Open Access Journals (Sweden)

    Peter Henry

    2016-10-01

    Full Text Available In commercial production settings, few options exist to prevent or treat angular leaf spot of strawberry, a disease of economic importance and caused by the bacterial pathogen Xanthomonas fragariae (Xfr. In the process of isolating and identifying Xfr bacteria from symptomatic plants, we observed growth inhibition of Xfr by bacterial isolates from the same leaf macerates. Identified as species of Pseudomonas and Rhizobium, these isolates were confirmed to suppress growth of Xfr in agar overlay plates and in microtiter plate cultures, as did our reference strain Pseudomonas putida KT2440. Screening of a transposon mutant library of KT2440 revealed that disruption of the biosynthetic pathway for the siderophore pyoverdine resulted in complete loss of Xfr antagonism, suggesting iron competition as a mode of action. Antagonism could be replicated on plate and in culture by addition of purified pyoverdine or by addition of the chelating agents tannic acid and dipyridyl, while supplementing the medium with iron negated the inhibitory effects of pyoverdine, tannic acid and dipyridyl. When co-inoculated with tannic acid onto strawberry plants, Xfr’s ability to cause foliar symptoms was greatly reduced, suggesting a possible opportunity for iron-based management of angular leaf spot. We discuss our findings in the context of ‘nutritional immunity’, the idea that plant hosts restrict pathogens access to iron, either directly, or indirectly through their associated microbiota.

  8. Bacterial anoxygenic photosynthesis on plant leaf surfaces.

    Science.gov (United States)

    Atamna-Ismaeel, Nof; Finkel, Omri; Glaser, Fabian; von Mering, Christian; Vorholt, Julia A; Koblížek, Michal; Belkin, Shimshon; Béjà, Oded

    2012-04-01

    The aerial surface of plants, the phyllosphere, is colonized by numerous bacteria displaying diverse metabolic properties that enable their survival in this specific habitat. Recently, we reported on the presence of microbial rhodopsin harbouring bacteria on the top of leaf surfaces. Here, we report on the presence of additional bacterial populations capable of harvesting light as a means of supplementing their metabolic requirements. An analysis of six phyllosphere metagenomes revealed the presence of a diverse community of anoxygenic phototrophic bacteria, including the previously reported methylobacteria, as well as other known and unknown phototrophs. The presence of anoxygenic phototrophic bacteria was also confirmed in situ by infrared epifluorescence microscopy. The microscopic enumeration correlated with estimates based on metagenomic analyses, confirming both the presence and high abundance of these microorganisms in the phyllosphere. Our data suggest that the phyllosphere contains a phylogenetically diverse assemblage of phototrophic species, including some yet undescribed bacterial clades that appear to be phyllosphere-unique. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  9. Species of Cercospora associated with grey leaf spot of maize.

    Science.gov (United States)

    Crous, Pedro W; Groenewald, Johannes Z; Groenewald, Marizeth; Caldwell, Pat; Braun, Uwe; Harrington, Thomas C

    2006-01-01

    Grey leaf spot is a serious yield-reducing disease of maize (Zea mays) in many parts of the world where this crop is cultivated. The causal organism associated with the disease is Cercospora zeae-maydis. Two potential sibling species have been recognized as Groups I and II. The DNA sequences for the internal transcribed spacers (ITS1 & ITS2), the 5.8S rRNA gene, elongation factor 1-alpha, histone H3, actin and calmodulin gene regions suggest that Groups I and II are two distinct species. Furthermore, Cercospora zeae-maydis (Group I) can be distinguished from C. zeina sp. nov. (Group II) by its faster growth rate on artificial media, the ability to produce cercosporin, longer conidiophores, and broadly fusiform conidia. A PCR-based test that distinguishes the two species was developed using species-specific primers designed from the histone H3 gene.

  10. Characterisation of bacterial brown spot pathogen from dry bean ...

    African Journals Online (AJOL)

    Pseudomonas syringae pv. syringae (Pss) causes bacterial brown spot (BBS) of beans (Phaseolus vulgaris L.), with yield losses of up to 55% in South Africa. Pss has a wide host range and for many of these, the pathogen has been biochemically and genetically characterised. However, few studies have been conducted on ...

  11. Biological control of bacterial spot of tomato by saprobe fungi from semi-arid areas of northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Douglas Casaroto Peitl

    2017-06-01

    Full Text Available Bacterial spot of tomato, caused by Xanthomonas spp., is a common disease in tomato fields that causes significant economic losses. Due to the difficulty with control of bacterial spot by conventional methods, new techniques such as biological control and induction of resistance are gaining prominence. This study aimed to select saprobe fungi from semi-arid regions of the Brazilian Northeast for the biological control of bacterial spot of tomato. To select the best isolates to control bacterial spot, a greenhouse experiment was initially conducted. Tomato plants (‘Santa Cruz Kada’ were treated with filtrates of 25 saprobe fungi and inoculated three days later with Xanthomonas euvesicatoria. Filtrates of Memnoniella levispora, Periconia hispidula, Zygosporium echinosporum, and Chloridium virescens var. virescens were selected as the most effective. Filtrates and volatile compounds from these four isolates were tested for their antibacterial activity in cultures of X. euvesicatoria and in tomato plants (‘Santa Cruz Kada’ inoculated with X. euvesicatoria. In vitro, the addition of nonvolatile fungal metabolites into the culture medium at 5% and 50% (v/v inhibited bacterial growth by 28.9% and 53.8%, respectively. The volatile compounds produced by C. virescens var. virescens reduced the number of colony-forming units of X. euvesicatoria by 25.9%. In vivo, all treatments reduced from 62.4 to 71.3% the area under bacterial spot progress curve, showing the same control efficacy as the commercial resistance inducer used as a positive control (acibenzolar-S-methyl. Systemicity of the fungal filtrates was confirmed in a separate experiment, where application of the treatments exclusively to the third leaf decreased the severity of the disease on the fourth leaf (except for C. virescens var. virescens. These results show that M. levispora, P. hispidula, Z. echinosporum, and C. virescens var. virescens are potential biocontrol agents against

  12. Inheritance of bacterial spot resistance in Capsicum annuum var. annuum.

    Science.gov (United States)

    Silva, L R A; Rodrigues, R; Pimenta, S; Correa, J W S; Araújo, M S B; Bento, C S; Sudré, C P

    2017-04-20

    Since 2008, Brazil is the largest consumer of agrochemicals, which increases production costs and risks of agricultural products, environment, and farmers' contamination. Sweet pepper, which is one of the main consumed vegetables in the country, is on top of the list of the most sprayed crops. The bacterial spot, caused by Xanthomonas spp, is one of the most damaging diseases of pepper crops. Genetic resistant consists of a suitable way of disease control, but development of durable resistant cultivars as well as understanding of plant-bacterium interaction is being a challenge for plant breeders and pathologists worldwide. Inheritance of disease resistance is often variable, depending on genetic background of the parents. The knowledge of the genetic base controlling such resistance is the first step in a breeding program aiming to develop new genotypes, bringing together resistance and other superior agronomic traits. This study reports the genetic basis of bacterial spot resistance in Capsicum annuum var. annuum using mean generation analysis from crosses between accessions UENF 2285 (susceptible) and UENF 1381 (resistant). The plants of each generation were grown in a greenhouse and leaflets were inoculated with bacterial strain ENA 4135 at 10 5 CFU/mL in 1.0 cm 2 of the mesophyll. Evaluations were performed using a scoring scale whose grades ranged from 1.0 (resistant) to 5.0 (susceptible), depending on symptom manifestation. Genetic control of bacterial spot has a quantitative aspect, with higher additive effect. The quantitative analysis showed that five genes were the minimum number controlling bacterial spot resistance. Additive effect was higher (6.06) than dominant (3.31) and explained 86.36% of total variation.

  13. QTL mapping of resistance to gray leaf spot in maize.

    Science.gov (United States)

    Zhang, Yan; Xu, Ling; Fan, Xingming; Tan, Jing; Chen, Wei; Xu, Mingliang

    2012-12-01

    Gray leaf spot (GLS), caused by the causal fungal pathogen Cercospora zeae-maydis, is one of the most serious foliar diseases of maize worldwide. In the current study, a highly resistant inbred line Y32 and a susceptible line Q11 were used to produce segregating populations for both genetic analysis and QTL mapping. The broad-sense heritability (H (2)) for GLS resistance was estimated to be as high as 0.85, indicating that genetic factors played key roles in phenotypic variation. In initial QTL analysis, four QTL, located on chromosomes 1, 2, 5, and 8, were detected to confer GLS resistance. Each QTL could explain 2.53-23.90 % of the total phenotypic variation, predominantly due to additive genetic effects. Two major QTL, qRgls1 and qRgls2 on chromosomes 8 and 5, were consistently detected across different locations and replicates. Compared to the previous results, qRgls2 is located in a 'hotspot' for GLS resistance; while, qRgls1 does not overlap with any other known resistance QTL. Furthermore, the major QTL-qRgls1 was fine-mapped into an interval of 1.4 Mb, flanked by the markers GZ204 and IDP5. The QTL-qRgls1 could enhance the resistance percentages by 19.70-61.28 %, suggesting its usefulness to improve maize resistance to GLS.

  14. Molecular Diagnostics in the Mycosphaerella Leaf Spot Disease Complex of Banana and for Radopholus similis

    NARCIS (Netherlands)

    Arzanlou, M.; Kema, G.H.J.; Waalwijk, C.; Carlier, I.; Vries, de P.M.; Guzmán, M.; Araya Vargas, M.; Helder, J.; Crous, P.W.

    2009-01-01

    Mycosphaerella leaf spots and nematodes threaten banana cultivation worldwide. The Mycosphaerella disease complex involves three related ascomycetous fungi: Mycosphaerella fijiensis, M. musicola and M. eumusae. The exact distribution of these three species and their disease epidemiology remain

  15. Short communication: Algal leaf spot associated with Cephaleuros virescens (Trentepohliales, Ulvophyceae on Nephelium lappaceum in Thailand

    Directory of Open Access Journals (Sweden)

    ANURAG SUNPAPAO

    2016-05-01

    Full Text Available Abstract. Sunpapao A, Pitaloka MK, Arikit S. 2015. Algal leaf spot associated with Cephaleuros virescens (Trentepohliales, Ulvophyceae on Nephelium lappaceum in Thailand. Biodiversitas 17: 31-35. Algal leaf spot disease of Nephelium lappaceum (rambutan was observed in southern Thailand. The algae were isolated on Bold’s basal medium (BBM and identified based on appearance of the lesions, algal morphology and molecular properties. Characteristics of the filamentous thallus cells, sporangiophores, sporangia, gametes and zoospores were clarified. A portion of the 18S small subunit rRNA was amplified to validate the morphological identification by sequence similarity. To summarize the main results, the plant parasite causing algal leaf spot was identified as Cephaleuros virescens, and in sequencing-based phylogenetic analysis the Cephaleuros PSU-R5.1 isolate from rambutan grouped with the algae in genus Cephaleuros. This confirms C. virescens as a causal organism of algal leaf spot disease on rambutan in southern Thailand.

  16. aqueous plant extracts for control of groundnut leaf spot in burkina

    African Journals Online (AJOL)

    ACSS

    2017-08-08

    Aug 8, 2017 ... Early and late leaf spots, the two fungal diseases of groundnut (Arachis hypogaea L.) caused by Cercospora arachidicola Hori. and .... effect of extracts of Azacdiractha indica on ... fruits of the other plants species were dried in.

  17. Characterization and pathogenicity of Fusarium species associated with leaf spot of mango (Mangifera indica L.).

    Science.gov (United States)

    Omar, Nurul Husna; Mohd, Masratulhawa; Mohamed Nor, Nik Mohd Izham; Zakaria, Latiffah

    2018-01-01

    Leaf spot diseases are mainly caused by fungi including Fusarium. In the present study several species of Fusarium were isolated from the leaf spot lesion of mango (Mangifera indica L.) Based on morphological characteristics, TEF-1α sequences and phylogenetic analysis, five species were identified as F. proliferatum, F. semitectum, F. mangiferae, F. solani and F. chlamydosporum. Pathogenicity test indicated that representative isolates of F. proliferatum, F. semitectum and F. chlamydosporum were pathogenic on mango leaves causing leaf spot with low to moderate virulence. Nevertheless, abundance of spots on the leaf can disrupt photosynthesis which in turn reduced growth, and lead to susceptibility to infection by opportunistic pathogens due to weakening of the plant. Fusarium solani and F. mangiferae were non-pathogenic and it is possible that both species are saprophyte which associated with nutrient availability on the surface of the leaf through decaying leave tissues. The occurrence of Fusarium spp. on the leaf spot lesion and the effect from the disease needs to be considered when developing disease management method of mango cultivation as numerous spot on the leaves could effect the photosynthesis process and finally giving low yield and less quality of mango. Copyright © 2017. Published by Elsevier Ltd.

  18. Pyramiding of blast and bacterial leaf blight resistance genes into ...

    African Journals Online (AJOL)

    Blast caused by the fungus Magnaporthe oryzae (Hebert) Barr. and bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) are two major diseases of rice (Oryza sativa). The use of varietal resistance is the most appropriate strategy for controlling the diseases, and molecular assisted selection can ...

  19. Genetic parameters and selection for resistance to bacterial spot in recombinant F6 lines of Capsicum annuum

    Directory of Open Access Journals (Sweden)

    Messias Gonzaga Pereira

    2009-01-01

    Full Text Available This study aimed to advance generations and select superior sweet pepper genotypes with resistance tobacterial spot, using the breeding method Single Seed Descent (SSD based on the segregating population derived from thecross between Capsicum annuum L. UENF 1421 (susceptible, non-pungent and UENF 1381 (resistant, pungent. Thesegregating F3 generation was grown in pots in a greenhouse until the F5 generation. The F6 generation was grown in fieldconditions. The reaction to bacterial spot was evaluated by inoculation with isolate ENA 4135 of Xanthomonas campestris pv.vesicatoria, based on a score scale and by calculating the area under the disease progress curve (AUDPC. The presence orabsence of capsaicin was also assessed. Eighteen F6 lines were bacterial leaf spot-resistant. Since no capsaicin was detectedin the F6 lines 032, 316, 399, 434, and 517, these will be used in the next steps of the sweet pepper breeding program.

  20. Leaf microbiota in an agroecosystem: spatiotemporal variation in bacterial community composition on field-grown lettuce.

    Science.gov (United States)

    Rastogi, Gurdeep; Sbodio, Adrian; Tech, Jan J; Suslow, Trevor V; Coaker, Gitta L; Leveau, Johan H J

    2012-10-01

    The presence, size and importance of bacterial communities on plant leaf surfaces are widely appreciated. However, information is scarce regarding their composition and how it changes along geographical and seasonal scales. We collected 106 samples of field-grown Romaine lettuce from commercial production regions in California and Arizona during the 2009-2010 crop cycle. Total bacterial populations averaged between 10(5) and 10(6) per gram of tissue, whereas counts of culturable bacteria were on average one (summer season) or two (winter season) orders of magnitude lower. Pyrosequencing of 16S rRNA gene amplicons from 88 samples revealed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria were the most abundantly represented phyla. At the genus level, Pseudomonas, Bacillus, Massilia, Arthrobacter and Pantoea were the most consistently found across samples, suggesting that they form the bacterial 'core' phyllosphere microbiota on lettuce. The foliar presence of Xanthomonas campestris pv. vitians, which is the causal agent of bacterial leaf spot of lettuce, correlated positively with the relative representation of bacteria from the genus Alkanindiges, but negatively with Bacillus, Erwinia and Pantoea. Summer samples showed an overrepresentation of Enterobacteriaceae sequences and culturable coliforms compared with winter samples. The distance between fields or the timing of a dust storm, but not Romaine cultivar, explained differences in bacterial community composition between several of the fields sampled. As one of the largest surveys of leaf surface microbiology, this study offers new insights into the extent and underlying causes of variability in bacterial community composition on plant leaves as a function of time, space and environment.

  1. Leaf microbiota in an agroecosystem: spatiotemporal variation in bacterial community composition on field-grown lettuce

    Science.gov (United States)

    Rastogi, Gurdeep; Sbodio, Adrian; Tech, Jan J; Suslow, Trevor V; Coaker, Gitta L; Leveau, Johan H J

    2012-01-01

    The presence, size and importance of bacterial communities on plant leaf surfaces are widely appreciated. However, information is scarce regarding their composition and how it changes along geographical and seasonal scales. We collected 106 samples of field-grown Romaine lettuce from commercial production regions in California and Arizona during the 2009–2010 crop cycle. Total bacterial populations averaged between 105 and 106 per gram of tissue, whereas counts of culturable bacteria were on average one (summer season) or two (winter season) orders of magnitude lower. Pyrosequencing of 16S rRNA gene amplicons from 88 samples revealed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria were the most abundantly represented phyla. At the genus level, Pseudomonas, Bacillus, Massilia, Arthrobacter and Pantoea were the most consistently found across samples, suggesting that they form the bacterial ‘core' phyllosphere microbiota on lettuce. The foliar presence of Xanthomonas campestris pv. vitians, which is the causal agent of bacterial leaf spot of lettuce, correlated positively with the relative representation of bacteria from the genus Alkanindiges, but negatively with Bacillus, Erwinia and Pantoea. Summer samples showed an overrepresentation of Enterobacteriaceae sequences and culturable coliforms compared with winter samples. The distance between fields or the timing of a dust storm, but not Romaine cultivar, explained differences in bacterial community composition between several of the fields sampled. As one of the largest surveys of leaf surface microbiology, this study offers new insights into the extent and underlying causes of variability in bacterial community composition on plant leaves as a function of time, space and environment. PMID:22534606

  2. Probabilities for profitable fungicide use against gray leaf spot in hybrid maize.

    Science.gov (United States)

    Munkvold, G P; Martinson, C A; Shriver, J M; Dixon, P M

    2001-05-01

    ABSTRACT Gray leaf spot, caused by the fungus Cercospora zeae-maydis, causes considerable yield losses in hybrid maize grown in the north-central United States and elsewhere. Nonchemical management tactics have not adequately prevented these losses. The probability of profitably using fungicide application as a management tool for gray leaf spot was evaluated in 10 field experiments under conditions of natural inoculum in Iowa. Gray leaf spot severity in untreated control plots ranged from 2.6 to 72.8% for the ear leaf and from 3.0 to 7.7 (1 to 9 scale) for whole-plot ratings. In each experiment, fungicide applications with propiconazole or mancozeb significantly reduced gray leaf spot severity. Fungicide treatment significantly (P leaf spot severity and yield. We used a Bayesian inference method to calculate for each experiment the probability of achieving a positive net return with one or two propiconazole applications, based on the mean yields and standard deviations for treated and untreated plots, the price of grain, and the costs of the fungicide applications. For one application, the probability ranged from approximately 0.06 to more than 0.99, and exceeded 0.50 in six of nine scenarios (specific experiment/hybrid). The highest probabilities occurred in the 1995 experiments with the most susceptible hybrid. Probabilities were almost always higher for a single application of propiconazole than for two applications. These results indicate that a single application of propiconazole frequently can be profitable for gray leaf spot management in Iowa, but the probability of a profitable application is strongly influenced by hybrid susceptibility. The calculation of probabilities for positive net returns was more informative than mean separation in terms of assessing the economic success of the fungicide applications.

  3. NOTE - Genetic control of resistance to gray leaf spot of maize in tropical germplasm

    Directory of Open Access Journals (Sweden)

    André Humberto de Brito

    2012-01-01

    Full Text Available The main goal of this study was to assess the nature and magnitude of gene effects for resistance to Cercospora leaf spot. A randomized block design with three replications was used. The data were obtained at the plant level by assessing the disease severity. The data were analyzed per experiment, using the average data per plot. A dominant-additive genetic model without epistasis was considered, with estimation of the components of means and variance. The genetic control of resistance to gray leaf spot is polygenic with predominance of the additive effects. Dominance was observed in a few small-effect loci and high heritability values.

  4. Cercospora apii causing leaf spots on two Brazilian toxic weeds: solanum glaucophyllum and Xanthium strumarium

    Directory of Open Access Journals (Sweden)

    Fabiano Branco Rocha

    2007-03-01

    Full Text Available Samples of two toxic weeds, Solanum glaucophyllum and Xanthium strumarium, bearing leaf spots symptoms were found. Cercospora apii was found associated to these leaf spots in both plants. These are the first reports of this fungus on these hosts in Brazil and its first report on S. glaucophyllum worldwide.Foram encontrados plantas das espécies Solanum glaucophyllum e Xanthium strumaruium apresentando sintomas de manchas foliares. Cercospora apii foi encontrado associado lesões foliares em ambas as plantas. Estes são os primeiros relatos desse fungo nestes hospedeiros no Brasil e o primeiro relato de sua ocorrência em S. glaucophyllum no mundo.

  5. Field evaluations of leaf spot resistance and yield in peanut genotypes in the United States and Bolivia

    Science.gov (United States)

    Field experiments were conducted in 2002-2006 to characterize yield potential and disease resistance to Cercospora arachidicola (early leaf spot) and Cercosporidium personatum (late leaf spot) in the Bolivian peanut (Arachis hypogaea) cultivar, Bayo Grande, and breeding lines developed from crosses ...

  6. A model-based approach to preplanting risk assessment for gray leaf spot of maize.

    Science.gov (United States)

    Paul, P A; Munkvold, G P

    2004-12-01

    ABSTRACT Risk assessment models for gray leaf spot of maize, caused by Cercospora zeae-maydis, were developed using preplanting site and maize genotype data as predictors. Disease severity at the dough/dent plant growth stage was categorized into classes and used as the response variable. Logistic regression and classification and regression tree (CART) modeling approaches were used to predict severity classes as a function of planting date (PD), amount of maize soil surface residue (SR), cropping sequence, genotype maturity and gray leaf spot resistance (GLSR) ratings, and longitude (LON). Models were development using 332 cases collected between 1998 and 2001. Thirty cases collected in 2002 were used to validate the models. Preplanting data showed a strong relationship with late-season gray leaf spot severity classes. The most important predictors were SR, PD, GLSR, and LON. Logistic regression models correctly classified 60 to 70% of the validation cases, whereas the CART models correctly classified 57 to 77% of these cases. Cases misclassified by the CART models were mostly due to overestimation, whereas the logistic regression models tended to misclassify cases by underestimation. Both the CART and logistic regression models have potential as management decision-making tools. Early quantitative assessment of gray leaf spot risk would allow for more sound management decisions being made when warranted.

  7. Somaclonal variation in hybrid poplars for resistance to Septoria leaf spot

    Science.gov (United States)

    M.E. Ostry; D. D. Skilling

    1987-01-01

    Tissue culture techniques have been used to obtain hybrid poplars with putative resistance to leaf spot caused by Septoria musiva from clones previously susceptible to the disease. Stem internode explants were used to obtain proliferating callus cultures. Adventitious bud formation and shoot proliferation were then induced. Elongated shoots were excised and rooted in a...

  8. Septoria-like pathogens causing leaf and fruit spot of pistachio

    NARCIS (Netherlands)

    Crous, P.W.; Quaedvlieg, W.; Sarpkaya, K.; Can, C.; Erkiliç, A.

    2013-01-01

    Several species of Septoria are associated with leaf and fruit spot of pistachio (Pistacia vera), though their identity has always been confused, making identification problematic. The present study elucidates the taxonomy of the Septoria spp. associated with pistachio, and distinguishes four

  9. Characterisation and epitypification of Pseudocercospora cladosporioides, the causal organism of Cercospora leaf spot of olives

    NARCIS (Netherlands)

    Avila, A.; Groenewald, J.Z.; Trapero, A.; Crous, P.W.

    2005-01-01

    Cercospora leaf spot of olives is a serious defoliating disease attributed to Pseudocercospora cladosporioides. Although the disease is well distributed throughout olive growing regions of the world, its epidemiology and population structure remains unknown. The aim of this study was to establish

  10. Reaction of the BASE 120 lines to angular leaf spot in Puerto Rico

    Science.gov (United States)

    Common bean (Phaseolus vulgaris L.) is limited by diseases such as Angular leaf spot (ALS), caused by Phaeoisariopsis griseola (Sacc.) Ferraris sin. Pseudocercospora griseola (Sacc.) Crous & U. Braun. The virulence of Phaeoisariopis griseola isolate ALS-9029-JD2 from Juana Diaz, PR was determined by...

  11. Neocordana gen. nov.,the causal organism of Cordana leaf spot on banana

    NARCIS (Netherlands)

    Hernández-Restrepo, Margarita; Groenewald, Johannes Z.; Crous, Pedro W.

    2015-01-01

    Cordana leaf spot of banana is shown to be associated with several species of a new genus described here as Neocordana gen. nov. Furthermore, Neocordana belongs to Pyriculariaceae (Magnaporthales) rather than Cordanaceae where the type species of Cordana, C. pauciseptata resides. Neocordana is

  12. Efficacy of management tools for control of Phytophthora plurivora leaf spot of Rhododendron, 2014

    Science.gov (United States)

    This study was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of leaf spot of Rhododendron caused by Phytophthora plurivora. The experiment was conducted by treating two-year old Rhododendron plants with fungicides on September 2...

  13. Stemphylium leaf spot of parsley in California caused by Stemphylium vesicarium

    Science.gov (United States)

    From 2009 through 2011, a previously undescribed disease occurred on commercial parsley in coastal (Ventura County) California. Symptoms of the disease consisted of circular to oval, tan to brown leaf spots and resulted in loss of crop quality and hence reduced yields. A fungus was consistently isol...

  14. Shoot Blight and Leaf Spot of Blueberry Anthracnose Caused by Colletotrichum acutatum

    OpenAIRE

    Shigenobu, YOSHIDA; Takao, TSUKIBOSHI; National Institute for Agro-Environmental Sciences; National Institute for Agro-Environmental Sciences

    2002-01-01

    Shoot blight and leaf spots were found on highbush blueberry trees in Tsukuba, Ibaraki, in 1999. The causal fungus was identified morphologically as Colletotrichum acutatum Simmonds ex Simmonds. This is the first report of blueberry anthracnose caused by C. acutatum in Japan.

  15. Aqueous plant extracts for control of groundnut leaf spot in Burkina ...

    African Journals Online (AJOL)

    Early and late leaf spots, the two fungal diseases of groundnut (Arachis hypogaea L.) caused by Cercospora arachidicola Hori. and Phaeoisariopsis personata (Berk and Curt), respectively, cause severe groundnut crop losses in arid zone of West Africa. The objective of this study was to evaluate efficacy of aqueous extracts ...

  16. Leaf bacterial diversity mediates plant diversity and ecosystem function relationships.

    Science.gov (United States)

    Laforest-Lapointe, Isabelle; Paquette, Alain; Messier, Christian; Kembel, Steven W

    2017-06-01

    Research on biodiversity and ecosystem functioning has demonstrated links between plant diversity and ecosystem functions such as productivity. At other trophic levels, the plant microbiome has been shown to influence host plant fitness and function, and host-associated microbes have been proposed to influence ecosystem function through their role in defining the extended phenotype of host organisms However, the importance of the plant microbiome for ecosystem function has not been quantified in the context of the known importance of plant diversity and traits. Here, using a tree biodiversity-ecosystem functioning experiment, we provide strong support for the hypothesis that leaf bacterial diversity is positively linked to ecosystem productivity, even after accounting for the role of plant diversity. Our results also show that host species identity, functional identity and functional diversity are the main determinants of leaf bacterial community structure and diversity. Our study provides evidence of a positive correlation between plant-associated microbial diversity and terrestrial ecosystem productivity, and a new mechanism by which models of biodiversity-ecosystem functioning relationships can be improved.

  17. Genetic control of the angular leaf spot reaction in common bean leaves and pods

    Directory of Open Access Journals (Sweden)

    Jerônimo Constantino Borel

    2011-12-01

    Full Text Available Information about genetic control of plant reaction to pathogens is essential in plant breeding programs focusing resistance. This study aimed to obtain information about genetic control of the angular leaf spot reaction in leaves and pods from common bean (Phaseolus vulgaris L. line ESAL 686. This line was crossed with cultivars Jalo EEP 558 (resistant, Cornell 49-242 (resistant and Carioca MG (susceptible. Generations F1, F2 and backcrosses (BC11 and BC21 were obtained. In the dry season (2009, parents and respective populations were evaluated for angular leaf spot reaction under field conditions. Disease severity was evaluated on leaves and pods using diagrammatic scales. Severity scores were obtained and mean and variance genetic components were estimated for both. Segregation of F2 generation was analyzed for some crosses. Different genes control angular leaf spot reaction in leaves and pods. Mean and variance components showed predominance of additive effects. Heritability was high, however, was greater on pods than on leaves which indicated that leaf reaction is more influenced by the environment.

  18. Calcium and potassium contents in nutrient solution on Phoma leaf spot intensity in coffee seedlings

    Directory of Open Access Journals (Sweden)

    Aricléia de Moraes Catarino

    Full Text Available ABSTRACT Coffee is one of the main export commodities of Brazilian agribusiness. Phoma leaf spot [Phoma tarda (Stewart Boerema & Bollen] is one of the most important coffee fungal diseases in Brazil. Therefore, this study aimed to evaluate the intensity of Phoma leaf spot in coffee seedlings supplied with different rates of Ca+2 and K+. The study was conducted under controlled conditions in a growth chamber, at the Department of Phytopathology - UFLA, from February 2010 to December 2011. The assay was repeated twice under the same conditions. The nutrient solutions consisted of five concentrations of K+ (3, 4, 5, 6, 7 mmol L-1 and Ca+2 (2, 4, 6, 8 and 10 mmol L-1. The experiment was arranged in a randomized block design, with 25 treatments and three replicates, with two plants per plot. The areas under incidence progress curve (AUIPC and severity (AUSPC were calculated. At the lowest rate of Ca2+ (2 mmol L-1 and highest K+ (6 and 7 mmol L-1, approximately, the AUIPC was the smallest. For the AUSPC, the lowest rates of Ca+2 and K+ resulted in the lowest severities. Supply of Ca+2 and K+ in nutrient solution reduced AUIPC and AUSPC of Phoma leaf spot, and these nutrients can be recommended for the management of the disease.

  19. Major QTL Conferring Resistance to Rice Bacterial Leaf Streak

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropical and sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no major resistant gene was located in rice until date. In the present study, a new major quantitative trait locus (QTL) conferring resistance to BLS was identified from a highly resistant variety Dular by the employment of Dular/Balilla (DB) and Dular/IR24 (DI) segregation populations and was designated qBLSR-11-1. This QTL was located between the simple sequence repeat (SSR) markers RM120 and RM441 on chromosome 11 and could account for 18.1-21.7% and 36.3% of the variance in DB and DI populations, respectively. The genetic pattern of rice resistance to BLS was discussed.

  20. First report of Elsinoe leaf and fruit spot and Elsinoe pyri on apple in Denmark

    DEFF Research Database (Denmark)

    Glazowska, Sylwia Emilia; Schiller, Michaela; Lund, Ole Søgaard

    2013-01-01

    . The associated pathogen has not previously been identi- fied, but symptoms are identical to those described for el- sinoe leaf and fruit spot (ELFS) caused by the ascomycete, Elsinoe pyri (Scheper et al., 2013). In 2012, DNA from fruit skin of apples was purified from two cultivars, Pigeon fra Juellinge...... (Scheper et al., 2013) were recovered by inoculating Topaz- spot infected fruit skin onto potato dextrose agar. Sequenc- ing of the ITS1-5.8S-ITS2 region revealed two identical 628 bp sequences (GenBank KC928079, KC928080) with 99% sequence identity to the previously published sequences of E. pyri. Our......An apple disease, known as “Topaz spot” in northern Europe (Trapman and Jansonius, 2008) has since year 2000 become widespread in Danish organic apple orchards (Malus domestica). Characteristic symptoms are small spots (black on fruits, brown on leaves) having a silvery-grey cen- tre...

  1. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-10-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacterial colonies in infected host cells (Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy, Ernstsen et al., 2017 [1]). The infected cells were imaged with a 10× objective and number of intracellular bacterial colonies, their size distribution and the number of cell nuclei were automatically quantified using a spot detection-tool. The spot detection-output was exported to Excel, where data analysis was performed. In this article, micrographs and spot detection data are made available to facilitate implementation of the method.

  2. Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

    OpenAIRE

    Lucas,Gilvaine Ciavareli; Alves,Eduardo; Pereira,Ricardo Borges; Perina,Fabiano José; Souza,Ricardo Magela de

    2012-01-01

    The objective of this work was to evaluate the effects of plant essential oils (EOs) on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings unde...

  3. Morphological and molecular characterization, sexual reproduction, and pathogenicity of Setosphaeria rostrata isolates from rice leaf spot.

    Science.gov (United States)

    Kusai, Nor Azizah; Azmi, Madihah Mior Zakuan; Zainudin, Nur Ain Izzati Mohd; Yusof, Mohd Termizi; Razak, Azmi Abd

    2016-09-01

    Setosphaeria rostrata, a common plant pathogen causing leaf spot disease, affects a wide range of plant species, mainly grasses. Fungi were isolated from brown spots on rice leaves throughout Peninsular Malaysia, and 45 isolates were identified as Setosphaeria rostrata The isolates were then characterized using morphological and molecular approaches. The mating type was determined using PCR amplification of the mating type alleles, and isolates of opposite mating types were crossed to examine sexual reproduction. Based on nuclear ribosomal DNA ITS1-5.8S-ITS2 region (ITS) and beta-tubulin (BT2) sequences, two phylogenetic trees were constructed using the maximum likelihood method; S. rostrata was clustered in one well-supported clade. Pathogenicity tests showed that S. rostrata isolates are pathogenic, suggesting that it is the cause of the symptoms. Mating-type analyses indicated that three isolates carried the MAT1-1 allele, and the other 42 isolates carried MAT1-2 After isolates with opposite mating types were crossed on Sach's medium and incubated for 3 wk, six crosses produced pseudothecia that contained eight mature ascospores, and 12 other crosses produced numerous pseudothecia with no ascospores. To our knowledge, this is the first report on S. rostrata isolated from leaf spots on rice. © 2016 by The Mycological Society of America.

  4. Predicting favorable conditions for early leaf spot of peanut using output from the Weather Research and Forecasting (WRF) model

    Science.gov (United States)

    Olatinwo, Rabiu O.; Prabha, Thara V.; Paz, Joel O.; Hoogenboom, Gerrit

    2012-03-01

    Early leaf spot of peanut ( Arachis hypogaea L.), a disease caused by Cercospora arachidicola S. Hori, is responsible for an annual crop loss of several million dollars in the southeastern United States alone. The development of early leaf spot on peanut and subsequent spread of the spores of C. arachidicola relies on favorable weather conditions. Accurate spatio-temporal weather information is crucial for monitoring the progression of favorable conditions and determining the potential threat of the disease. Therefore, the development of a prediction model for mitigating the risk of early leaf spot in peanut production is important. The specific objective of this study was to demonstrate the application of the high-resolution Weather Research and Forecasting (WRF) model for management of early leaf spot in peanut. We coupled high-resolution weather output of the WRF, i.e. relative humidity and temperature, with the Oklahoma peanut leaf spot advisory model in predicting favorable conditions for early leaf spot infection over Georgia in 2007. Results showed a more favorable infection condition in the southeastern coastline of Georgia where the infection threshold were met sooner compared to the southwestern and central part of Georgia where the disease risk was lower. A newly introduced infection threat index indicates that the leaf spot threat threshold was met sooner at Alma, GA, compared to Tifton and Cordele, GA. The short-term prediction of weather parameters and their use in the management of peanut diseases is a viable and promising technique, which could help growers make accurate management decisions, and lower disease impact through optimum timing of fungicide applications.

  5. Potential of Trichoderma species on Helminthosporium causing leaf spot on cane palm, Chrysalidocarpus lutescens.

    Science.gov (United States)

    Jegathambigai, V; Karunaratne, M D S D; Svinningen, A; Mikunthan, G

    2008-01-01

    The cane palm, Chrysalidocarpus lutescens is one among the plant material of the export industries in Sri Lanka. The export quality of C. lutescens was declined due to the repeated occurrence of a leaf spot caused by Helminthosporium. Widespread occurrence of the leaf spot affected the cane palm production and succumb it to a huge setback in the floriculture industry in Sri Lanka. Being an export industry eco-friendly means of disease control was the prime focus for a better management of such vulnerable disease. Trichoderma is a potential bio agent, which has definite role in suppressing the inoculum of Helminthosporium sp. This study aims to evaluate the efficacy of Trichoderma species to control naturally established leaf spot in cane palm under field conditions. Three isolates of T. viride and two isolates of T. harzianum were evaluated. All the Trichoderma species performed significantly in reducing the disease incidence. T. viride + T. harzianum combination (1 x 10(10) cfu/ml) was the best compared to chemical in decreasing the mean disease severity index and improving the frequency of healthy plants. The colour of the leaves regained due to the application of Trichoderma sp. The results revealed that leaf spot incidence was lowered significantly in cane palms treated with Trichoderma species followed by treatment with combination of Trichoderma sp. and fungicides. The fungicide mixture (hexaconozole 50 g/l + Isoprothiolane 400 g/l) failed to lower the disease incidence and had no effect in suppressing the inocula of Helminthosporium, although recommended. Mixing of Trichoderma species with fungicide did not exhibit any additive effect. The combination of different species of Trichoderma would target species of Helminthosporium that exist as a complex group under field conditions. The results also proved that the existence of heterogeneity in Helminthosporium that could be tackled and effectively controlled by a combination of different species of the bio

  6. Occurrence of angular leaf spot caused by Pseudocercospora griseola in Phaseolus vulgaris in Asturias, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Landeras, E.; Trapiello, E.; Braña, M.; González, A.J.

    2017-07-01

    Angular leaf spot (ALS) symptoms were observed in 2015 in common bean fields at four locations in Asturias, NW Spain. This disease is frequent in tropical areas and we have no record of its presence in our region, at least in the last 30 years. However, since its detection its presence in the crops has been increasing. Symptoms were necrotic spots on leaves and reddish-brown to black circular spots on pods, stems, branches and petioles. The damage observed in the mentioned crops was highly variable (between 60% and 100% affected leaves), being most severe in crops where no agrochemical treatment were applied. Three strains were selected and identified based in morphological features as Pseudocercospora griseola. The ITS region was amplified by PCR obtaining a sequence that was identical for the three isolates (Acc. No. LT222499). This sequence showed 99-100% similarity with those deposited in databases corresponding to P. griseola. To fulfill Koch's postulates, a pathogenicity test was carried out in two common bean cultivars (‘Andecha’ and ‘Maruxina’). P. griseola was re-isolated from inoculated plants and not from control plants. In cv. ‘Andecha’, chlorosis was observed in all the inoculated plants, before the appearance of spots. Consequently this is the first confirmed report of this pathogen in our region.

  7. The disease prevalence and severity of Cercospora leaf spot in sugar beet cultivations in Kayseri

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    Hacer Handan ALTINOK

    2012-12-01

    Full Text Available Cercospora leaf spot disease (Cercospora beticola Sacc., is one of the most economically important fungal diseases in sugar beet growing. Under appropriate climatic conditions, the disease can reach epidemic levels. Although some fungicides exist for disease control, resistance development by pathogen against fungicides is creating difficulties. Besides, use of resistant varieties which is considered as the most efficient and environment-friendly method is adversely affected by pathogen’s ability to exhibit high genetic variations and varying resistance levels against different races of pathogen restricts the success of resistance breeding studies. In order to reveal status of this disease in Kayseri province, surveys were conducted in 2010 and 2011 in sugar beet growing areas and disease prevalence and severity were determined. Approximately, 1500 da area in 90 fields were examined and about 700 da of this area found as infected with Cercospora leaf spot disease in both years of the survey. Highest disease prevalence and severity were found as 80 % and 45 %, respectively, in Sarıoğlan district, which is followed by central district, Develi and Bünyan. Among surveyed districts, lowest prevalence and severity were detected as approx. 65 % and 35 %, respectively, in Yeşilhisar.

  8. Molecular variability in the maize grey leaf spot pathogens in Brazil

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    Kátia R. Brunelli

    2008-01-01

    Full Text Available Isolates of Cercospora species from leaves displaying symptoms of grey leaf spot were collected in maize-producing areas of south-central Brazil in 2001 and 2002. Restriction digests of the internal transcribed spacer region of rDNA detected the presence of the same two Cercospora species described on maize in the United States, namely C. zeae-maydis and the recently described species, C. zeina . Genetic variability among isolates was assessed by analysing 104 amplified fragment length polymorphism loci. Cluster analysis confirmed the genetic separation of isolates into two species with a mean similarity of 35%. Similarity levels within species were high, averaging 93% and 92% among isolates of C. zeae-maydis and C. zeina , respectively. The mean genetic similarity between C. zeae-maydis and C. zeina and two isolates of C. sorghi f. sp. maydis was 45% and 35%, respectively. Results of this study showed that populations of the grey leaf spot pathogens in Brazil are similar to those in the United States regarding species composition and that C. zeina is also present in Brazil.

  9. Morphological and molecular characterization of Cladosporium cladosporioides species complex causing pecan tree leaf spot.

    Science.gov (United States)

    Walker, C; Muniz, M F B; Rolim, J M; Martins, R R O; Rosenthal, V C; Maciel, C G; Mezzomo, R; Reiniger, L R S

    2016-09-16

    The objective of this study was to characterize species of the Cladosporium cladosporioides complex isolated from pecan trees (Carya illinoinensis) with symptoms of leaf spot, based on morphological and molecular approaches. Morphological attributes were assessed using monosporic cultures on potato dextrose agar medium, which were examined for mycelial growth, sporulation, color, and conidia and ramoconidia size. Molecular characterization comprised isolation of DNA and subsequent amplification of the translation elongation factor 1α (TEF-1α) region. Three species of the C. cladosporioides complex were identified: C. cladosporioides, Cladosporium pseudocladosporioides, and Cladosporium subuliforme. Sporulation was the most important characteristic differentiating species of this genus. However, morphological features must be considered together with molecular analysis, as certain characters are indistinguishable between species. TEF-1αcan be effectively used to identify and group isolates belonging to the C. cladosporioides complex. The present study provides an important example of a methodology to ascertain similarity between isolates of this complex causing leaf spot in pecan trees, which should facilitate future pathogenicity studies.

  10. Essential Oil of Cymbopogon citratus on the Control of the Curvularia Leaf Spot Disease on Maize

    Science.gov (United States)

    Mourão, Dalmarcia de Sousa Carlos; Ferreira de Souza Pereira, Talita; de Souza, Danival José; Chagas Júnior, Aloísio Freitas; Veloso, Ronice Alves; Leão, Evelynne Urzêdo

    2017-01-01

    The Curvularia Leaf Spot is becoming more common due to the culture expansion and the low resistance of the cultivated genotypes in tropical regions. Thus, the objective was to evaluate the fungitoxicity of the essential oil of Cymbopogon citratus upon the phytopathogen Curvularia lunata, causative agent of the Curvularia Leaf Spot. There was realized pathogenicity tests of C. lunata in maize plants, phytotoxicity of the essential oil of C. citratus and gas chromatography attached, germination tests of the conidia, and of in vitro inhibition of C. lunata. Also, there were realized tests aiming at verifying the phytopathogen control in vivo. In the pathogenicity tests, there were verified symptoms of the disease in all of the suspensions tested on plants. It was observed that the essential oil concentrations of 7.5 µL mL−1 to 50 µL mL−1 were phytotoxic. The majoritarian chemical components of the essential oil of C. citratus were Geranial (41.46%) and Neral (32.43%). The concentrations of 5 and 7.5 µL mL−1 inhibited 100% of conidia germination. None of the concentrations evaluated effectively inhibited C. lunata mycelial growth in in vitro tests. In the preventive control, the concentration of 7.5 µL mL−1 was sufficient for the reduction of the progress of the disease, however the curative control was not efficient on the tested dosages. PMID:28930276

  11. A review on threat of gray leaf spot disease of maize in Asia

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    Narayan Bahadur Dhami

    2015-12-01

    Full Text Available Biotic and biotic constraints are yield limiting factors in maize producing regions. Among these gray leaf spot is a yield limiting foliar disease of maize in high land regions of Asia. This review is done from related different national and international journals, thesis, books, research papers etc. The objectives of this review are to become familiar with genetics and inheritance, epidemiology, symptoms and disease management strategies etc. High relative humidity, temperature, minimum tillage and maize monoculture are important factors responsible for disease development. The sibling species of Cercospora zeae-maydis (Tehon and Daniels, 1925 Group I and Group II and Cercospora sorghai var. maydis (Chupp, 1954 are associated with this disease. Pathogens colonize in maize debris. Conidia are the source of inoculums for disease spread. Severe blighting of leaves reduces sugars, stalk lodging and causes premature death of plants resulting in yield losses of up to 100%. Disease management through cultural practices is provisional. The use of fungicides for emergencies is effective however; their prohibitive cost and detrimental effects on the environment are negative consequences. The inheritance of tolerance is quantitative with small additive effects. The introgression of resistant genes among the crosses of resistant germplasm enhances the resistance. The crosses of resistant and susceptible germplasm possess greater stability than the crosses of susceptible and resistant germplasm. The development of gray leaf spot tolerant populations through tolerance breeding principle is an economical and sustainable approach to manage the disease.

  12. Severity of banana leaf spot in an intercropping system in two cycles of banana Prata Anã

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    Valdeir Dias Gonçalves

    2008-01-01

    Full Text Available Prata Anã is the most planted banana cultivar in northern Minas Gerais, Brazil. It is however susceptible toseveral pathogens. This study was carried out to evaluate the disease severity of banana leaf spot in the Prata Anã cv. in thefirst and second cycle under six different planting systems. The randomized block experimental design was used with sixtreatments and four replications. In an evaluation of the severity of banana leaf spot, no disease symptoms were found onThap Maeo and Caipira. The evolution curve of the disease indicated seasonal effects in the first and second cycles. Theseverity of banana leaf spot was highest soon after the regional rainy period from November to March. A comparison of themeans of the evaluations indicated a reduction in disease severity from the first to the second cycle.

  13. Regression and artificial neural network modeling for the prediction of gray leaf spot of maize.

    Science.gov (United States)

    Paul, P A; Munkvold, G P

    2005-04-01

    ABSTRACT Regression and artificial neural network (ANN) modeling approaches were combined to develop models to predict the severity of gray leaf spot of maize, caused by Cercospora zeae-maydis. In all, 329 cases consisting of environmental, cultural, and location-specific variables were collected for field plots in Iowa between 1998 and 2002. Disease severity on the ear leaf at the dough to dent plant growth stage was used as the response variable. Correlation and regression analyses were performed to select potentially useful predictor variables. Predictors from the best 9 of 80 regression models were used to develop ANN models. A random sample of 60% of the cases was used to train the networks, and 20% each for testing and validation. Model performance was evaluated based on coefficient of determination (R(2)) and mean square error (MSE) for the validation data set. The best models had R(2) ranging from 0.70 to 0.75 and MSE ranging from 174.7 to 202.8. The most useful predictor variables were hours of daily temperatures between 22 and 30 degrees C (85.50 to 230.50 h) and hours of nightly relative humidity >/=90% (122 to 330 h) for the period between growth stages V4 and V12, mean nightly temperature (65.26 to 76.56 degrees C) for the period between growth stages V12 and R2, longitude (90.08 to 95.14 degrees W), maize residue on the soil surface (0 to 100%), planting date (in day of the year; 112 to 182), and gray leaf spot resistance rating (2 to 7; based on a 1-to-9 scale, where 1 = most susceptible to 9 = most resistant).

  14. Foliar Application of the Fungicide Pyraclostrobin Reduced Bacterial Spot Disease of Pepper

    OpenAIRE

    Beom Ryong Kang; Jang Hoon Lee; Young Cheol Kim

    2018-01-01

    Pyraclostrobin is a broad-spectrum fungicide that inhibits mitochondrial respiration. However, it may also induce systemic resistance effective against bacterial and viral diseases. In this study, we evaluated whether pyraclostrobin enhanced resistance against the bacterial spot pathogen, Xanthomonas euvesicatora on pepper (Capsicum annuum). Although pyraclostrobin alone did not suppressed the in vitro growth of X. euvesicatoria, disease severity in pepper was significantly lower by 69% after...

  15. Plant growth and leaf-spot severity on eucalypt at different CO2 concentrations in the air

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    Carlos Eduardo Oliveira da Silva

    2014-03-01

    Full Text Available The objective of this work was to evaluate the effects of increased air-CO2 concentration on plant growth and on leaf-spot caused by Cylindrocladium candelabrum in Eucalyptus urophylla. Seedlings were cultivated for 30 days at 451, 645, 904, and 1,147 µmol mol-1 CO2 ; then, they were inoculated with the pathogen and kept under the same conditions for seven days. Increased CO2 concentration increased plant height and shoot dry matter mass, and decreased disease incidence and severity. Stem diameter was not affected by the treatments. Increased concentrations of atmospheric CO2 favorably affect eucalypt growth and reduce leaf-spot severity.

  16. Screening of Potential Inhibitor against Coat Protein of Apple Chlorotic Leaf Spot Virus.

    Science.gov (United States)

    Purohit, Rituraj; Kumar, Sachin; Hallan, Vipin

    2018-06-01

    In this study, we analyzed Coat protein (CP) of Apple chlorotic leaf spot virus (ACLSV), an important latent virus on Apple. Incidence of the virus is upto 60% in various apple cultivars, affecting yield losses of the order of 10-40% (depending upon the cultivar). CP plays an important role as the sole building block of the viral capsid. Homology approach was used to model 193 amino acid sequence of the coat protein. We used various servers such as ConSurf, TargetS, OSML, COACH, COFACTOR for the prediction of active site residues in coat protein. Virtual screening strategy was employed to search potential inhibitors for CP. Top twenty screened molecules considered for drugability, and toxicity analysis and one potential molecule was further analyzed by docking analysis. Here, we reported a potent molecule which could inhibit the formation of viron assembly by targeting the CP protein of virus.

  17. Xanthomonas euvesicatoria Causes Bacterial Spot Disease on Pepper Plant in Korea

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    Min-Seong Kyeon

    2016-10-01

    Full Text Available In 2004, bacterial spot-causing xanthomonads (BSX were reclassified into 4 species—Xanthomonas euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Bacterial spot disease on pepper plant in Korea is known to be caused by both X. axonopodis pv. vesicatoria and X. vesicatoria. Here, we reidentified the pathogen causing bacterial spots on pepper plant based on the new classification. Accordingly, 72 pathogenic isolates were obtained from the lesions on pepper plants at 42 different locations. All isolates were negative for pectolytic activity. Five isolates were positive for amylolytic activity. All of the Korean pepper isolates had a 32 kDa-protein unique to X. euvesicatoria and had the same band pattern of the rpoB gene as that of X. euvesicatoria and X. perforans as indicated by PCR-restriction fragment length polymorphism analysis. A phylogenetic tree of 16S rDNA sequences showed that all of the Korean pepper plant isolates fit into the same group as did all the reference strains of X. euvesicatoria and X. perforans. A phylogenetic tree of the nucleotide sequences of 3 housekeeping genes—gapA, gyrB, and lepA showed that all of the Korean pepper plant isolates fit into the same group as did all of the references strains of X. euvesicatoria. Based on the phenotypic and genotypic characteristics, we identified the pathogen as X. euvesicatoria. Neither X. vesicatoria, the known pathogen of pepper bacterial spot, nor X. perforans, the known pathogen of tomato plant, was isolated. Thus, we suggest that the pathogen causing bacterial spot disease of pepper plants in Korea is X. euvesicatoria.

  18. Bacterial filamentation accelerates colonization of adhesive spots embedded in biopassive surfaces

    International Nuclear Information System (INIS)

    Möller, Jens; Emge, Philippe; Vizcarra, Ima Avalos; Kollmannsberger, Philip; Vogel, Viola

    2013-01-01

    Sessile bacteria adhere to engineered surfaces and host tissues and pose a substantial clinical and economical risk when growing into biofilms. Most engineered and biological interfaces are of chemically heterogeneous nature and provide adhesive islands for bacterial attachment and growth. To mimic either defects in a surface coating of biomedical implants or heterogeneities within mucosal layers (Peyer's patches), we embedded micrometre-sized adhesive islands in a poly(ethylene glycol) biopassive background. We show experimentally and computationally that filamentation of Escherichia coli can significantly accelerate the bacterial surface colonization under physiological flow conditions. Filamentation can thus provide an advantage to a bacterial population to bridge non-adhesive distances exceeding 5 μm. Bacterial filamentation, caused by blocking of bacterial division, is common among bacterial species and can be triggered by environmental conditions or antibiotic treatment. While great awareness exists that the build-up of antibiotic resistance serves as intrinsic survival strategy, we show here that antibiotic treatment can actually promote surface colonization by triggering filamentation, which in turn prevents daughter cells from being washed away. Our combined microfabrication and computational approaches provide quantitative insights into mechanisms that enable biofouling of biopassive surfaces with embedded adhesive spots, even for spot distances that are multiples of the bacterial length. (paper)

  19. Bacterial filamentation accelerates colonization of adhesive spots embedded in biopassive surfaces

    Science.gov (United States)

    Möller, Jens; Emge, Philippe; Avalos Vizcarra, Ima; Kollmannsberger, Philip; Vogel, Viola

    2013-12-01

    Sessile bacteria adhere to engineered surfaces and host tissues and pose a substantial clinical and economical risk when growing into biofilms. Most engineered and biological interfaces are of chemically heterogeneous nature and provide adhesive islands for bacterial attachment and growth. To mimic either defects in a surface coating of biomedical implants or heterogeneities within mucosal layers (Peyer's patches), we embedded micrometre-sized adhesive islands in a poly(ethylene glycol) biopassive background. We show experimentally and computationally that filamentation of Escherichia coli can significantly accelerate the bacterial surface colonization under physiological flow conditions. Filamentation can thus provide an advantage to a bacterial population to bridge non-adhesive distances exceeding 5 μm. Bacterial filamentation, caused by blocking of bacterial division, is common among bacterial species and can be triggered by environmental conditions or antibiotic treatment. While great awareness exists that the build-up of antibiotic resistance serves as intrinsic survival strategy, we show here that antibiotic treatment can actually promote surface colonization by triggering filamentation, which in turn prevents daughter cells from being washed away. Our combined microfabrication and computational approaches provide quantitative insights into mechanisms that enable biofouling of biopassive surfaces with embedded adhesive spots, even for spot distances that are multiples of the bacterial length.

  20. Sibling species of cercospora associated with gray leaf spot of maize.

    Science.gov (United States)

    Wang, J; Levy, M; Dunkle, L D

    1998-12-01

    ABSTRACT Monoconidial isolates of the fungus causing gray leaf spot of maize were obtained from diseased leaves collected throughout the United States and analyzed for genetic variability at 111 amplified fragment length polymorphism (AFLP) loci. Cluster analysis revealed two very distinct groups of Cercospora zeae-maydis isolates. Both groups were found to be relatively uniform internally with an average genetic similarity among isolates of approximately 93 and 94%, respectively. The groups were separated from each other by a genetic distance of approximately 80%, a distance greater than that separating each group from the sorghum pathogen, C. sorghi (67 to 70%). Characteristics and dimensions of conidia and conid-iophores produced on infected plants or nutrient media were unreliable criteria for taxonomic differentiation of isolates composing the two groups of C. zeae-maydis. Nucleotide sequences of 5.8S ribosomal DNA (rDNA) and the internal transcribed spacer (ITS) regions were identical within each group but different between the two groups and different from C. sorghi. Restriction fragment length polymorphisms generated by digestion of the 5.8S rDNA and ITS regions with TaqI readily distinguished each group and C. sorghi. Isolates in one group were generally distributed throughout maize-producing regions of the United States; isolates in the other group were localized in the eastern third of the country. Both types were present in the same fields at some locations. The genetic distance based on AFLP profiles and different ITS nucleotide sequences between the two morphologically indistinguishable groups indicate that they are sibling species. Although it is unlikely that breeding for resistance to gray leaf spot will be confounded by local or regional variation in the pathogen, a vigilant approach is warranted, because two pathogenic species exist with unknown abilities to evolve new pathotypes.

  1. Progresso da mancha-bacteriana do pimentão a partir de diferentes níveis iniciais de inóculo e do emprego ou não do controle com oxicloreto de cobre Progress of bacterial leaf spot of pepper starting with different initial quantities of infected seedlings and treatment with the use or not of copper oxichloride

    Directory of Open Access Journals (Sweden)

    Margarida Goréte Ferreira do Carmo

    2001-11-01

    Full Text Available O presente trabalho teve como objetivo avaliar o progresso da mancha-bacteriana do pimentão a partir de quatro quantidades iniciais de mudas infectadas (0; 3,3; 10 e 100% associado à aplicação semanal de oxicloreto de cobre (2,4 g de i.a./L de água ou não. Foram conduzidos cinco ensaios, em condições de campo, em Seropédica (RJ, entre junho de 1996 e setembro de 1999. Quantificou-se a intensidade de doença, regularmente, por meio de estimativas visuais da severidade da doença (área foliar lesionada e desfolha e calculou-se a área abaixo da curva de progresso da doença normalizada (AACPD/ número de dias. Estas foram submetidas à Análise de Variância (p=0,01 e à análise de regressão linear em função do logaritmo da quantidade inicial de mudas infectadas. A redução do inóculo inicial teve efeito direto na quantidade final de doença, e de forma mais marcante sob condições mais propícias ao desenvolvimento da doença. A eficiência do oxicloreto de cobre foi variável e na maioria das vezes ineficiente, principalmente nos períodos mais propícios a epidemia, com redução de sua eficiência pela elevação da temperatura.The progress of pepper leaf spot was examined starting with different initial quantities of infected seedlings (0; 3.3; 10; and 100%, treated or not with chemical control through the weekly application of copper oxichloride (2.4 g of i.a/L of water. Five experiments were undertaken in Seropédica (Rio de Janeiro, Brazil in different time periods from June, 1996 to September, 1999. The intensity of disease was quantified regularly through visual estimation of disease severity (leaf area with lesions and leaf loss. The values for the area under the disease progress curves were calculated (AUDPC/number of days. The data was subjected to analysis of variance (p<0,01 and simple linear regression analysis was employed for the values of AUDPC/day in function of the initial quantity of infected seedlings. The

  2. Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

    Science.gov (United States)

    Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

    2018-02-01

    Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

  3. Salicylic acid confers enhanced resistance to Glomerella leaf spot in apple.

    Science.gov (United States)

    Zhang, Ying; Shi, Xiangpeng; Li, Baohua; Zhang, Qingming; Liang, Wenxing; Wang, Caixia

    2016-09-01

    Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots in apple. Currently, there are no effective means to control this disease except for the traditional fungicide sprays. Induced resistance by elicitors against pathogens infection is a widely accepted eco-friendly strategy. In the present study, we investigated whether exogenous application of salicylic acid (SA) could improve resistance to GLS in a highly susceptible apple cultivar (Malus domestica Borkh. cv. 'Gala') and the underlying mechanisms. The results showed that pretreatment with SA, at 0.1-1.0 mM, induced strong resistance against GLS in 'Gala' apple leaves, with SA treated leaves showing significant reduction in lesion numbers and disease index. Concurrent with the enhanced disease resistance, SA treatment markedly increased the total antioxidant capacity (T-AOC) and defence-related enzyme activities, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). As expected, SA treatment also induced the expression levels of five pathogenesis-related (PR) genes including PR1, PR5, PR8, Chitinase and β-1,3-glucanase. Furthermore, the most pronounced and/or rapid increase was observed in leaves treated with SA and subsequently inoculated with G. cingulata compared to the treatment with SA or inoculation with the pathogen. Together, these results suggest that exogenous SA triggered increase in reactive oxygen species levels and the antioxidant system might be responsible for enhanced resistance against G. cingulata in 'Gala' apple leaves. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Response of sugar beet plants to ultraviolet-B (280-320 nm) radiation and Cercospora leaf spot disease

    International Nuclear Information System (INIS)

    Panagopoulos, I.; Bornman, J.F.; Björn, L.O.

    1992-01-01

    Sugar beet (Beta vulgaris L.) plants injected with Cercospora beticola Sacc. as well as non-infected plants were grown under visible light with or without ultraviolet-B (UV-B, 280-320 nm) radiation for 40 days. An interaction between UV-B radiation and Cercospora leaf spot disease was observed, resulting in a large reduction in leaf chlorophyll content, dry weight of leaf laminae, petioles and storage roots. Lipid peroxidation in leaves also increased the most under the combined treatments. This was also true for ultraweak luminescence from both adaxial and abaxial leaf surfaces. However, no correlation between lipid peroxidation and ultraweak luminescence was observed. Ultraviolet-B radiation given alone appeared to have either a stimulating effect, giving an increase in dry weight of laminac and reducing lipid peroxidation, or no effect. This lack of effect was seen in the absence of change in dry weight of storage roots and chlorophyll content relative to controls. The study demonstrated a harmful interaction between UV-B radiation and Cercospora leaf spot disease on sugar beet

  5. Bacterial leaf scorch distribution and isothermal lines (PROJECT NC-EM-08-02)

    Science.gov (United States)

    Gerard C. Adams; Mursel Catall; James Walla; Ann B. Gould

    2013-01-01

    Bacterial leaf scorch (BLS) of shade trees is the common name for a disease caused by Xylella fastidiosa, a xylem-inhabiting bacterium that has fastidious nutritional requirements and is difficult to culture or verify by culturing. Forest trees including oak, sycamore, elm, planetree, sweetgum, mulberry and maple are species susceptible to ...

  6. Antifungal Potential of Indigenous Medicinal Plants against Myrothecium Leaf Spot of Bitter Gourd ( Momordica charantia L.

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    Muhammad Abid

    2017-08-01

    Full Text Available ABSTRACT Bitter gourd is of great importance due to its usage against the treatment of numerous ailments in human beings. A comprehensive survey at four localities of Southern Punjab, Pakistan was carried out to determine the severity of Myrothecium leaf spot. Maximum disease severity was at C1 (Chak 11/NP and least at C2 (Kot Mehtab. Among isolated species Myrothecium roridum was found more prevalent and pathogenic as compared to M. verrucaria. Antifungal activity using solvent extracts of five medicinal plants (Mangifera indica, Melia azedarach, Nicotiana tabacum, Moringa oleifera and Eucalyptus globosum were evaluated against isolated species by agar well diffusion method at various concentrations (0.01, 0.10, 1.0 and 10.0 µg / mL. N. tabacum revealed maximum zone size (13.40 mm and 8.28 mm with ethanol and chloroform solvents respectively followed by M. azedarach (9.00mm and 6.48mm. However, least inhibition was observed with ethanol and chloroform extracts of E. globosum (6.04mm and 3.88mm zone size respectively. Ethanol extracts showed highest activity when compared to chloroform extracts. Qualitative phytochemical analysis showed that all the selected plants are rich in chemical compounds such as alkaloids, terpenoids, flavonoids and phenols whereas Saponins was only present in N. tabacum while absent in rest of the extracts.

  7. Genetic diversity and apple leaf spot disease resistance characterization assessed by SSR markers

    Directory of Open Access Journals (Sweden)

    Gustavo H.F. Klabunde

    2016-09-01

    Full Text Available Among the cultivation problems of apple production in Brazil, Apple Leaf Spot (ALS disease represents one of the main breeding challenges. This study aims at analyzing the genetic diversity among 152 apple scion accessions available at the Apple Gene Bank of EPAGRI, located in Caçador, Santa Catarina/ Brazil. Eleven genomic SSR loci were analyzed to assess genetic diversity of ALS resistant and susceptible accessions. Results revealed high genetic diversity of the studied accessions, being 120 exclusive alleles (67 unique from scion accessions resistant to ALS, and a mean PIC of 0.823. The locus Probability of Identity (I ranged from 0.017 to 0.089. The combined I was 4.11 x 10-16, and the Power of Exclusion was 99.99999259%. In addition, the DNA fingerprint patterns will contribute as additional descriptors to select parental for crosses and early identification of apple accessions for breeding purposes, and also for cultivar protection.

  8. Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

    Directory of Open Access Journals (Sweden)

    Gilvaine Ciavareli Lucas

    2012-03-01

    Full Text Available The objective of this work was to evaluate the effects of plant essential oils (EOs on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings under greenhouse conditions. The effects of citronella, lemongrass, clove, and tea tree EOs, at 0.1%, on X. vesicatoria cells were evaluated by transmission electron microscopy. All EOs showed direct toxic effect on the bacteria at a 10%-concentration in vitro. Under greenhouse conditions, the EOs of clove, citronella, tea tree, and lemongrass reduced disease severity. EOs of clove and tea tree, and streptomycin sulfate promoted loss of electron-dense material and alterations in the cytoplasm, whereas EO of tea tree promoted cytoplasm vacuolation, and those of citronella, lemongrass, clove, and tea tree caused damage to the bacterial cell wall. The EOs at a concentration of 0.1% reduce the severity of the disease.

  9. New Generation of Resistant Sugar Beet Varieties for Advanced Integrated Management of Cercospora Leaf Spot in Central Europe

    OpenAIRE

    Johannes Vogel; Johannes Vogel; Christine Kenter; Carsten Holst; Bernward Märländer

    2018-01-01

    Cercospora leaf spot (CLS) epidemics in sugar beet have been increasing in recent years causing higher use of fungicides. Concomitantly, the availability of effective fungicides is at risk because of resistance development in the fungus, the lack of new active ingredients as well as restrictive approval practices. A key option for an integrated management of CLS is cultivation of resistant varieties. Because of the yield penalty in resistant varieties, acceptance in commercial practice so far...

  10. Identification of Isolates that Cause a Leaf Spot Disease of Brassicas as Xanthomonas campestris pv. raphani and Pathogenic and Genetic Comparison with Related Pathovars.

    Science.gov (United States)

    Vicente, J G; Everett, B; Roberts, S J

    2006-07-01

    ABSTRACT Twenty-five Xanthomonas isolates, including some isolates received as either X. campestris pv. armoraciae or pv. raphani, caused discrete leaf spot symptoms when spray-inoculated onto at least one Brassica oleracea cultivar. Twelve of these isolates and four other Xanthomonas isolates were spray- and pin-inoculated onto 21 different plant species/cultivars including horseradish (Armoracia rusticana), radish (Raphanus sativus), and tomato (Lycopersicon esculentum). The remaining 13 leaf spot isolates were spray-inoculated onto a subset of 10 plant species/cultivars. The leaf spot isolates were very aggressive on several Brassica spp., radish, and tomato causing leaf spots and dark sunken lesions on the middle vein, petiole, and stem. Based on the differential reactions of several Brassica spp. and radish cultivars, the leaf spot isolates were divided into three races, with races 1 and 3 predominating. A differential series was established to determine the race-type of isolates and a gene-for-gene model based on the interaction of two avirulence genes in the pathogen races and two matching resistance genes in the differential hosts is proposed. Repetitive-DNA polymerase chain reaction-based fingerprinting was used to assess the genetic diversity of the leaf spot isolates and isolates of closely related Xanthomonas pathovars. Although there was variability within each race, the leaf spot isolates were clustered separately from the X. campestris pv. campestris isolates. We propose that X. campestris isolates that cause a nonvascular leaf spot disease on Brassica spp. should be identified as pv. raphani and not pv. armoraciae. Race-type strains and a neopathotype strain for X. campestris pv. raphani are proposed.

  11. Fenton reagent and titanium dioxide nanoparticles as antifungal agents to control leaf spot of sugar beet under field conditions

    Directory of Open Access Journals (Sweden)

    Hamza Amany

    2016-07-01

    Full Text Available In this study, foliar sprays of Fenton solutions (Fenton reaction, Fenton-like reaction and Fenton complex, titanium dioxide (TiO2 and the recommended fungicide (chlorothalonil were estimated in the control of sugar beet leaf spot caused by Cercospora beticola under field conditions in two growing seasons. In addition, the impacts of these treatments on some crop characters (leaf dry weight, root fresh weight, soluble solid content, sucrose content and purity of sugar were examined. Biochemical and histological changes in the livers and kidneys of treated rats compared to an untreated control were utilized to assess the toxicity of the examined curative agents. Overall, chlorothalonil and Fenton complex were the most effective treatments for disease suppression in both tested seasons followed by Fenton-like reagent, Fenton’s reagent and TiO2, respectively. Growth and yield characters of treated sugar beet significantly increased in comparison to an untreated control. There were mild or no (biochemical and histological changes in the livers and kidneys of treated rats compared to the control. Fenton solutions and TiO2 may offer a new alternative for leaf spot control in sugar beet.

  12. Bacterial spot and early blight biocontrol by epiphytic bacteria in tomato plants

    Directory of Open Access Journals (Sweden)

    Roberto Lanna Filho

    2010-12-01

    Full Text Available The objective of this work was to evaluate in vitro and in vivo biocontrol of bacterial spot (Xanthomonas vesicatoria and early blight (Alternaria solani by the epiphytic bacteria Paenibacillus macerans and Bacillus pumilus. Tomato plants were previously sprayed with epiphytic bacteria, benzalkonium chloride and PBS buffer and, after four days, they were inoculated with A. solani and X. vesicatoria. To determine the phytopathogenic bacteria population, leaflet samples were collected from each treatment every 24 hours, for seven days, and plated on semi-selective medium. The effect of epiphytic bacteria over phytopathogens was performed by the antibiosis test and antagonistic activity measured by inhibition zone diameter. The epiphytic and benzalkonium chloride drastically reduced the severity of early blight and bacterial spot in comparison to the control (PBS. In detached leaflets, the epiphytic bacteria reduced in 70% the number of phytopathogenic bacteria cells in the phylloplane. The antibiosis test showed that the epiphytic bacteria efficiently inhibit the phytopathogens growth. In all the bioassays, the epiphytic bacteria protect tomato plants against the phytopathogens

  13. Grazing of leaf-associated Cercomonads (Protists: Rhizaria: Cercozoa) structures bacterial community composition and function.

    Science.gov (United States)

    Flues, Sebastian; Bass, David; Bonkowski, Michael

    2017-08-01

    Preferential food selection in protists is well documented, but we still lack basic understanding on how protist predation modifies the taxonomic and functional composition of bacterial communities. We conducted feeding trials using leaf-associated cercomonad Cercozoa by incubating them on a standardized, diverse bacterial community washed from plant leaves. We used a shotgun metagenomics approach to investigate the taxonomic and functional changes of the bacterial community after five days protist predation on bacteria. Predation-induced shifts in bacterial community composition could be linked to phenotypic protist traits. Protist reproduction rate, morphological plasticity and cell speed were most important in determining bacterial community composition. Analyses of co-occurrence patterns showed less complex correlations between bacterial taxa in the protist-grazed treatments with a higher proportion of positive correlations than in non-grazed controls, suggesting that predation reduced the influence of strong competitors. Protist predation influenced 14 metabolic core functions including membrane transport from which type VI secretion systems were in particular upregulated. In view of the functional importance of bacterial communities in the phyllosphere and rhizosphere of plants, a more detailed understanding of predator-prey interactions, changes in microbial composition and function, and subsequent repercussions on plant performance are clearly required. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Bacterial Leaf Scorch of Amenity Trees a Wide-Spread Problem of Economic Significance to the Urban Forest

    Science.gov (United States)

    James Lashomb; Alan Iskra; Ann Brooks Gould; George Hamilton

    2003-01-01

    Bacterial leaf scorch (BLS) of amenity trees is caused by the bacterium Xylella fastidiosa, a xylem-limited pathogen that causes water stress resulting in leaf scorch, decline, and eventual death of affected trees. Recent surveys indicate that BLS is widespread throughout the eastern half of the United States. In New Jersey, BLS primarily affects red and pin oaks...

  15. Culture dependent and independent analysis of bacterial communities associated with commercial salad leaf vegetables

    Science.gov (United States)

    2013-01-01

    Background Plants harbor a diverse bacterial community, both as epiphytes on the plant surface and as endophytes within plant tissue. While some plant-associated bacteria act as plant pathogens or promote plant growth, others may be human pathogens. The aim of the current study was to determine the bacterial community composition of organic and conventionally grown leafy salad vegetables at the point of consumption using both culture-dependent and culture-independent methods. Results Total culturable bacteria on salad vegetables ranged from 8.0 × 103 to 5.5 × 108 CFU g-1. The number of culturable endophytic bacteria from surface sterilized plants was significantly lower, ranging from 2.2 × 103 to 5.8 × 105 CFU g-1. Cultured isolates belonged to six major bacterial phyla, and included representatives of Pseudomonas, Pantoea, Chryseobacterium, and Flavobacterium. Eleven different phyla and subphyla were identified by culture-independent pyrosequencing, with Gammaproteobacteria, Betaproteobacteria, and Bacteroidetes being the most dominant lineages. Other bacterial lineages identified (e.g. Firmicutes, Alphaproteobacteria, Acidobacteria, and Actinobacteria) typically represented less than 1% of sequences obtained. At the genus level, sequences classified as Pseudomonas were identified in all samples and this was often the most prevalent genus. Ralstonia sequences made up a greater portion of the community in surface sterilized than non-surface sterilized samples, indicating that it was largely endophytic, while Acinetobacter sequences appeared to be primarily associated with the leaf surface. Analysis of molecular variance indicated there were no significant differences in bacterial community composition between organic versus conventionally grown, or surface-sterilized versus non-sterilized leaf vegetables. While culture-independent pyrosequencing identified significantly more bacterial taxa, the dominant taxa from pyrosequence data were also detected by

  16. Culture dependent and independent analysis of bacterial communities associated with commercial salad leaf vegetables.

    Science.gov (United States)

    Jackson, Colin R; Randolph, Kevin C; Osborn, Shelly L; Tyler, Heather L

    2013-12-01

    Plants harbor a diverse bacterial community, both as epiphytes on the plant surface and as endophytes within plant tissue. While some plant-associated bacteria act as plant pathogens or promote plant growth, others may be human pathogens. The aim of the current study was to determine the bacterial community composition of organic and conventionally grown leafy salad vegetables at the point of consumption using both culture-dependent and culture-independent methods. Total culturable bacteria on salad vegetables ranged from 8.0 × 10(3) to 5.5 × 10(8) CFU g(-1). The number of culturable endophytic bacteria from surface sterilized plants was significantly lower, ranging from 2.2 × 10(3) to 5.8 × 10(5) CFU g(-1). Cultured isolates belonged to six major bacterial phyla, and included representatives of Pseudomonas, Pantoea, Chryseobacterium, and Flavobacterium. Eleven different phyla and subphyla were identified by culture-independent pyrosequencing, with Gammaproteobacteria, Betaproteobacteria, and Bacteroidetes being the most dominant lineages. Other bacterial lineages identified (e.g. Firmicutes, Alphaproteobacteria, Acidobacteria, and Actinobacteria) typically represented less than 1% of sequences obtained. At the genus level, sequences classified as Pseudomonas were identified in all samples and this was often the most prevalent genus. Ralstonia sequences made up a greater portion of the community in surface sterilized than non-surface sterilized samples, indicating that it was largely endophytic, while Acinetobacter sequences appeared to be primarily associated with the leaf surface. Analysis of molecular variance indicated there were no significant differences in bacterial community composition between organic versus conventionally grown, or surface-sterilized versus non-sterilized leaf vegetables. While culture-independent pyrosequencing identified significantly more bacterial taxa, the dominant taxa from pyrosequence data were also detected by traditional

  17. Characterization of Apricot pseudo-chlorotic leaf spot virus, A Novel Trichovirus Isolated from Stone Fruit Trees.

    Science.gov (United States)

    Liberti, D; Marais, A; Svanella-Dumas, L; Dulucq, M J; Alioto, D; Ragozzino, A; Rodoni, B; Candresse, T

    2005-04-01

    ABSTRACT A trichovirus closely related to Apple chlorotic leaf spot virus (ACLSV) was detected in symptomatic apricot and Japanese plum from Italy. The Sus2 isolate of this agent cross-reacted with anti-ACLSV polyclonal reagents but was not detected by broad-specificity anti- ACLSV monoclonal antibodies. It had particles with typical trichovirus morphology but, contrary to ACLSV, was unable to infect Chenopodium quinoa and C. amaranticolor. The sequence of its genome (7,494 nucleotides [nt], missing only approximately 30 to 40 nt of the 5' terminal sequence) and the partial sequence of another isolate were determined. The new virus has a genomic organization similar to that of ACLSV, with three open reading frames coding for a replication-associated protein (RNA-dependent RNA polymerase), a movement protein, and a capsid protein, respectively. However, it had only approximately 65 to 67% nucleotide identity with sequenced isolates of ACLSV. The differences in serology, host range, genome sequence, and phylogenetic reconstructions for all viral proteins support the idea that this agent should be considered a new virus, for which the name Apricot pseudo-chlorotic leaf spot virus (APCLSV) is proposed. APCLSV shows substantial sequence variability and has been recovered from various Prunus sources coming from seven countries, an indication that it is likely to have a wide geographical distribution.

  18. Mapping Late Leaf Spot Resistance in Peanut (Arachis hypogaea Using QTL-seq Reveals Markers for Marker-Assisted Selection

    Directory of Open Access Journals (Sweden)

    Josh Clevenger

    2018-02-01

    Full Text Available Late leaf spot (LLS; Cercosporidium personatum is a major fungal disease of cultivated peanut (Arachis hypogaea. A recombinant inbred line population segregating for quantitative field resistance was used to identify quantitative trait loci (QTL using QTL-seq. High rates of false positive SNP calls using established methods in this allotetraploid crop obscured significant QTLs. To resolve this problem, robust parental SNPs were first identified using polyploid-specific SNP identification pipelines, leading to discovery of significant QTLs for LLS resistance. These QTLs were confirmed over 4 years of field data. Selection with markers linked to these QTLs resulted in a significant increase in resistance, showing that these markers can be immediately applied in breeding programs. This study demonstrates that QTL-seq can be used to rapidly identify QTLs controlling highly quantitative traits in polyploid crops with complex genomes. Markers identified can then be deployed in breeding programs, increasing the efficiency of selection using molecular tools.Key Message: Field resistance to late leaf spot is a quantitative trait controlled by many QTLs. Using polyploid-specific methods, QTL-seq is faster and more cost effective than QTL mapping.

  19. Medicinal plants - a potent antibacterial source against bacterial leaf blight (BLB) of rice

    International Nuclear Information System (INIS)

    Jabeen, R.

    2011-01-01

    The antibacterial potential of indigenous medicinal plants as alternative chemical pesticides for controlling bacterial leaf blight (BLB) of rice was investigated. Twenty-five different species of medicinal plants were collected from various sites in Pakistan. Decoctions of all medicinal plant species were screened by the disc plate diffusion method for testing the susceptibility of an aggressive isolate of Xanthomonas oryzae pv. oryzae (Xoo 105). Out of twenty five medicinal plants, Thuja orientalis (cone + leaves), Azadirachta indica (seeds + fruits), Amomum subulatum (fruits), Terminalia chebula (fruits), Terminalia bellirica (fruits), Anethum graveolens (fruits) and Ferula assa-foetida (fruits) decoctions showed significant activity. The efficacy of decoctions from six promising plants were further tested through detached leaf, glasshouse and field assays. A decoction of Terminalia chebula demonstrated the highest effectiveness in terms of regulating BLB in the plants both under laboratory and field conditions. Bioactive fractions of Terminalia chebula were purified, characterized and tentatively identified as allegic acid. (author)

  20. Season, Irrigation, Leaf Age, and Escherichia coli Inoculation Influence the Bacterial Diversity in the Lettuce Phyllosphere

    Science.gov (United States)

    Williams, Thomas R.; Moyne, Anne-Laure; Harris, Linda J.; Marco, Maria L.

    2013-01-01

    The developmental and temporal succession patterns and disturbance responses of phyllosphere bacterial communities are largely unknown. These factors might influence the capacity of human pathogens to persist in association with those communities on agriculturally-relevant plants. In this study, the phyllosphere microbiota was identified for Romaine lettuce plants grown in the Salinas Valley, CA, USA from four plantings performed over 2 years and including two irrigation methods and inoculations with an attenuated strain of Escherichia coli O157:H7. High-throughput DNA pyrosequencing of the V5 to V9 variable regions of bacterial 16S rRNA genes recovered in lettuce leaf washes revealed that the bacterial diversity in the phyllosphere was distinct for each field trial but was also strongly correlated with the season of planting. Firmicutes were generally most abundant in early season (June) plantings and Proteobacteria comprised the majority of bacteria recovered later in the year (August and October). Comparisons within individual field trials showed that bacterial diversity differed between sprinkler (overhead) and drip (surface) irrigated lettuce and increased over time as the plants grew. The microbiota were also distinct between control and E. coli O157:H7-inoculated plants and between E. coli O157:H7-inoculated plants with and without surviving pathogen cells. The bacterial inhabitants of the phyllosphere therefore appear to be affected by seasonal, irrigation, and biological factors in ways that are relevant for assessments of fresh produce food safety. PMID:23844230

  1. Exobasidium maculosum, a new species causing leaf and fruit spots on blueberry in the southeastern USA and its relationship with other Exobasidium spp. parasitic to blueberry and cranberry.

    Science.gov (United States)

    Brewer, Marin Talbot; Turner, Ashley N; Brannen, Phillip M; Cline, William O; Richardson, Elizabeth A

    2014-01-01

    Exobasidium leaf and fruit spot of blueberry (Vaccinium section Cyanococcus) is an emerging disease that has rapidly increased in prevalence throughout the southeastern USA. To determine whether this disease is caused by a new species of Exobasidium, we studied the morphology and phylogenetic relationship of the causal fungus compared with other members of the genus, including the type species E. vaccinii and other species that parasitize blueberry and cranberry (V. macrocarpon). Both scanning electron microscopy and light microscopy were used for morphological characterization. For phylogenetic analyses, we sequenced the large subunit of the rDNA (LSU) from 10 isolates collected from leaf or fruit spots of rabbiteye blueberry (V. virgatum), highbush blueberry (V. corymbosum) and southern highbush blueberry (Vaccinium interspecific hybrid) from Georgia and North Carolina and six isolates from leaf spots of lowbush blueberry (V. angustifolium) from Maine and Nova Scotia, Canada. LSU was sequenced from isolates causing red leaf disease of lowbush blueberry and red leaf spot (E. rostrupii) and red shoot (E. perenne) of cranberry. In addition, LSU sequences from GenBank, including sequences with high similarity to the emerging parasite and from Exobasidium spp. parasitizing other Vaccinium spp. and related hosts, were obtained. All sequences were aligned and subjected to phylogenetic analyses. Results indicated that the emerging parasite in the southeastern USA differs morphologically and phylogenetically from other described species and is described herein as Exobasidium maculosum. Within the southeastern USA, clustering based on host species, host tissue type (leaf or fruit) or geographic region was not detected; however, leaf spot isolates from lowbush blueberry were genetically different and likely represent a unique species. © 2014 by The Mycological Society of America.

  2. Protective Activity of the Mixtures of Pine Oil and Copper Hydroxide against Bacterial Spot and Anthracnose on Red Pepper

    Directory of Open Access Journals (Sweden)

    Jae-Woo Soh

    2014-09-01

    Full Text Available This research was performed to examine the protective activities of the mixtures of pine oil and copper hydroxide against bacterial spot and anthracnose on pepper plants. As for bacterial spot, the treatment of pine oil alone displayed high disease incidence (59.6% and low protective effect (28.9%. In comparison, the treatments of mixtures and copper hydroxide alone showed protective activities of 66.8-76.1%. The mixture of pine oil and copper hydroxide (4:1 suppressed the most effectively bacterial spot on pepper. On the other hand, the mixture of pine oil and copper hydroxide (4:1 also showed the strongest protective effect against pepper anthracnose among the 4 treatments tested; its disease incidence and disease control value were 49.8% and 41.7%, respectively. The other treatments showed low protective activities with control values of 7.4-17.1%. These results suggested that the mixture of pine oil and copper hydroxide (4:1 can be used for the environmental-friendly disease control of bacterial spot and anthracnose on pepper.

  3. Identification of Antipathogenic Bacterial Coral Symbionts Against Porites Ulcerative White Spots Disease

    Science.gov (United States)

    Sa'adah, Nor; Sabdono, Agus; Diah Permata Wijayanti, dan

    2018-02-01

    Coral reef ecosystems are ecosystems that are vulnerable and susceptible to damage due to the exploitation of ocean resources. One of the factors that cause coral damage is the disease that attacks the coral. Porites Ulcerative White Spots (PUWS) is a coral disease found in Indonesia and attacks the coral genera Porites allegedly caused by pathogenic microbial attacks. The purpose of this study was to identify the symbiotic bacteria on healthy coral that have antipatogenic potency against PUWS. The method used in this research was descriptive explorative. Sampling was done in Kemujan Island, Karimunjawa. Bacteria were isolated from healthy coral and coral affected by PUWS disease. Streak method was used to purify coral bacteria, while overlay and agar diffusion were used to test antipathogenic activity. Bacterial identification was carried out based on polyphasic approach. The results of this study showed that coral bacterial symbionts have antipathogenic activity against PUWS disease. The selected bacteria NM 1.2, NM 1.3 and KPSH 5. NM1.2 were closely related to Pseudoalteromonas piscicida, Pseudoalteromonas flavipulchra and Bacillus flexus, respectively.

  4. Plant Growth Promotion and Suppression of Bacterial Leaf Blight in Rice by Inoculated Bacteria.

    Directory of Open Access Journals (Sweden)

    Sumera Yasmin

    Full Text Available The present study was conducted to evaluate the potential of rice rhizosphere associated antagonistic bacteria for growth promotion and disease suppression of bacterial leaf blight (BLB. A total of 811 rhizospheric bacteria were isolated and screened against 3 prevalent strains of BLB pathogen Xanthomonas oryzae pv. oryzae (Xoo of which five antagonistic bacteria, i.e., Pseudomonas spp. E227, E233, Rh323, Serratia sp. Rh269 and Bacillus sp. Rh219 showed antagonistic potential (zone of inhibition 1-19 mm. Production of siderophores was found to be the common biocontrol determinant and all the strains solubilized inorganic phosphate (82-116 μg mL-1 and produced indole acetic acid (0.48-1.85 mg L-1 in vitro. All antagonistic bacteria were non-pathogenic to rice, and their co-inoculation significantly improved plant health in terms of reduced diseased leaf area (80%, improved shoot length (31%, root length (41% and plant dry weight (60% as compared to infected control plants. Furthermore, under pathogen pressure, bacterial inoculation resulted in increased activity of defense related enzymes including phenylalanine ammonia-lyase and polyphenol oxidase, along with 86% increase in peroxidase and 53% increase in catalase enzyme activities in plants inoculated with Pseudomonas sp. Rh323 as well as co-inoculated plants. Bacterial strains showed good colonization potential in the rice rhizosphere up to 21 days after seed inoculation. Application of bacterial consortia in the field resulted in an increase of 31% in grain yield and 10% in straw yield over non-inoculated plots. Although, yield increase was statistically non-significant but was accomplished with overall saving of 20% chemical fertilizers. The study showed that Pseudomonas sp. Rh323 can be used to develop dual-purpose inoculum which can serve not only to suppress BLB but also to promote plant growth in rice.

  5. Development of the variety for resistance against bacterial leaf-blight in rice with thermal neutrons

    International Nuclear Information System (INIS)

    Nakai, Hirokazu

    1990-01-01

    In search for the development of genes for resistance against bacterial leaf-blight in rice, thermal neutrons generated from the Research Reactor at the Kyoto University have been applied to the breeding. In this paper, the developmental outcome is described, and a potential application of thermal neutrons for breeding the variety of resistance against bacterial leaf-blight in rice is reviewed. When thermal neutrons were delivered to the rice, the ratio of absorbed doses by B-10, which is contained in a small quantity in the plant, was found to be larger than expected. This implies characteristic effects of thermal neutrons on the plant. When boric acid was incorporated into the plant before irradiation, the effect of thermal neutrons per irradiation time was considered to become great. The frequency of mutations for resistance was significantly higher by thermal neutron, as compared with that induced by other mutagens, such as gamma radiation, ethylene-imine, ethyl-methane-sulfonate, and nitroso-methyl-urea. Genetic analysis of mutants for resistance revealed recessive genes and polygenes. Finally, the application of thermal neutrons and other radiations would contribute greatly to a resolution of serious pollution problems in global food and environment. (N.K.)

  6. SH1 leaf rust and bacterial halo blight coffee resistances are genetically independent

    Directory of Open Access Journals (Sweden)

    Lucas Mateus Rivero Rodrigues

    Full Text Available ABSTRACT Coffee resistance to Pseudomonas syringae pv. garcae has been associated to pleiotropic effect of SH1 allele, present in coffee plants resistant to certain races of Hemileia vastatrix, the causal agent of leaf rust, or genetic linkage between resistance alleles to both pathogens. To validate this hypothesis, 63 coffee plants in F2 generation were evaluated for resistance to 2 isolates of H. vastatrix carriers of alleles, respectively, v2, v5 (isolate I/2015 and v1; v2; v5 (isolate II/2015 with the objective to confirm presence of SH1 allele in resistant plants to isolate I/2015. The same coffee plants were evaluated for resistance to a mixture of P. syringae pv. garcae strains highly pathogenic to coffee. Results showed that, among F2 coffee allele SH1 carriers, resistant to isolate I/2015, resistant and susceptible plants to bacterial halo blight were found; the same segregation occurs between F2 homozygous for SH1 allele, susceptible to the same isolate (I/2015 of H. vastatrix. Results also indicate that there is no pleiotropic effect of gene or allele SH1 connection between genes conferring resistance to leaf rust caused by H. vastatrix and bacterial halo blight caused by P. syringae pv. garcae.

  7. Effect of foliar fertilizer and fungicidal protection against leaf spot diseases on winter wheat

    Directory of Open Access Journals (Sweden)

    Agnieszka Mączyńska

    2012-12-01

    Full Text Available Field experiments were carried out in the seasons 2000/2001 and 2001/2002 in Plant Protection Institute, Sooenicowice Branch to assess the influence of foliar fertilizers such as Ekolist PK 1, Ekolist Mg, Mikrosol Z and Urea on healthiness of winter wheat. Foliar fertilizers were mixed with fungicides. The fungicides were applied at full or half recommended doses. The effect of the disease on wheat leaves was evaluated three times in each vegetation season. Remaining green leaf area (GLA of leaves was also determined. GLA of the leaves F-1 was not significantly different for each combination with different fertilization and different levels of chemical treatment. The application of foliar fertilizer only had no effect on green leaf area (GLA. The results indicate that foliar fertilization of all experimental plots improved leaf condition and therefore halted the development of wheat leaf diseases. The increases of 1000 grain mass and yield was high for each plot where a fertilizer and a full or half dose of a fungicide was applied. Foliar fertilizing with no chemical control had no proven effect on studied parameters.

  8. Draft genome sequence of Cercospora sojina isolate S9, a fungus causing frogeye leaf spot (FLS disease of soybean

    Directory of Open Access Journals (Sweden)

    Fanchang Zeng

    2017-06-01

    Full Text Available Fungi are the causal agents of many of the world's most serious plant diseases causing disastrous consequences for large-scale agricultural production. Pathogenicity genomic basis is complex in fungi as multicellular eukaryotic pathogens. The fungus Cercospora sojina is a plant pathogen that threatens global soybean supplies. Here, we report the genome sequence of C. sojina strain S9 and detect genome features and predicted genomic elements. The genome sequence of C. sojina is a valuable resource with potential in studying the fungal pathogenicity and soybean host resistance to frogeye leaf spot (FLS, which is caused by C. sojina. The C. sojina genome sequence has been deposited and available at DDBJ/EMBL/GenBank under the project accession number AHPQ00000000.

  9. Characterization of apple stem grooving virus and apple chlorotic leaf spot virus identified in a crab apple tree.

    Science.gov (United States)

    Li, Yongqiang; Deng, Congliang; Bian, Yong; Zhao, Xiaoli; Zhou, Qi

    2017-04-01

    Apple stem grooving virus (ASGV), apple chlorotic leaf spot virus (ACLSV), and prunus necrotic ringspot virus (PNRSV) were identified in a crab apple tree by small RNA deep sequencing. The complete genome sequence of ACLSV isolate BJ (ACLSV-BJ) was 7554 nucleotides and shared 67.0%-83.0% nucleotide sequence identity with other ACLSV isolates. A phylogenetic tree based on the complete genome sequence of all available ACLSV isolates showed that ACLSV-BJ clustered with the isolates SY01 from hawthorn, MO5 from apple, and JB, KMS and YH from pear. The complete nucleotide sequence of ASGV-BJ was 6509 nucleotides (nt) long and shared 78.2%-80.7% nucleotide sequence identity with other isolates. ASGV-BJ and the isolate ASGV_kfp clustered together in the phylogenetic tree as an independent clade. Recombination analysis showed that isolate ASGV-BJ was a naturally occurring recombinant.

  10. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L..

    Directory of Open Access Journals (Sweden)

    Juliana Morini Küpper Cardoso Perseguini

    Full Text Available The common bean (Phaseolus vulgaris L. is the world's most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum and angular leaf spot (ALS; Pseudocercospora griseola are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will

  11. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Perseguini, Juliana Morini Küpper Cardoso; Oblessuc, Paula Rodrigues; Rosa, João Ricardo Bachega Feijó; Gomes, Kleber Alves; Chiorato, Alisson Fernando; Carbonell, Sérgio Augusto Morais; Garcia, Antonio Augusto Franco; Vianello, Rosana Pereira; Benchimol-Reis, Luciana Lasry

    2016-01-01

    The common bean (Phaseolus vulgaris L.) is the world's most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum) and angular leaf spot (ALS; Pseudocercospora griseola) are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL) controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will contribute to more

  12. Fitness and competition studies of QoI resistant and sensitive Cercospora sojina isolates, the causal agent of frogeye leaf spot

    Science.gov (United States)

    Frogeye leaf spot (FLS), caused by Cercospora sojina, is a yearly foliar disease of soybean in Tennessee and causes substantial economic losses if not properly managed. Quinone outside inhibitor (QoI) fungicides are often used to manage FLS, but C. sojina isolates have developed resistance to this c...

  13. Using SNP genetic markers to elucidate the linkage of the Co-34/Phg-3 anthracnose and angular leaf spot resistance gene cluster with the Ur-14 resistance gene

    Science.gov (United States)

    The Ouro Negro common bean cultivar contains the Co-34/Phg-3 gene cluster that confers resistance to the anthracnose (ANT) and angular leaf spot (ALS) pathogens. These genes are tightly linked on chromosome 4. Ouro Negro also has the Ur-14 rust resistance gene, reportedly in the vicinity of Co- 34; ...

  14. Fine mapping of a quantitative resistance gene for gray leaf spot of maize (Zea mays L.) derived from teosinte (Z. mays ssp. parviglumis)

    Science.gov (United States)

    In previous work, using near isogenic line (NIL) populations in which segments of the tesosinte (Zea mays ssp. parviglumis) genome had been introgressed into the background of the maize line B73, we had identified a QTL on chromosome 8, here called Qgls8, for gray leaf spot resistance. We identified...

  15. Two alternative recessive quantitative trait loci influence resistance to spring black stem and leaf spot in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Oliver Richard P

    2008-03-01

    Full Text Available Abstract Background Knowledge of the genetic basis of plant resistance to necrotrophic pathogens is incomplete and has been characterised in relatively few pathosystems. In this study, the cytology and genetics of resistance to spring black stem and leaf spot caused by Phoma medicaginis, an economically important necrotrophic pathogen of Medicago spp., was examined in the model legume M. truncatula. Results Macroscopically, the resistant response of accession SA27063 was characterised by small, hypersensitive-like spots following inoculation while the susceptible interaction with accessions A17 and SA3054 showed necrotic lesions and spreading chlorosis. No unique cytological differences were observed during early infection (2 populations segregating for resistance to spring black stem and leaf spot were established between SA27063 and the two susceptible accessions, A17 and SA3054. The cross between SA27063 and A17 represented a wider cross than between SA27063 and SA3054, as evidenced by higher genetic polymorphism, reduced fertility and aberrant phenotypes of F2 progeny. In the SA27063 × A17 F2 population a highly significant quantitative trait locus (QTL, LOD = 7.37; P Phoma medicaginis one (rnpm1 genetically mapped to the top arm of linkage group 4 (LG4. rnpm1 explained 33.6% of the phenotypic variance in the population's response to infection depicted on a 1–5 scale and was tightly linked to marker AW256637. A second highly significant QTL (LOD = 6.77; P rnpm2, was located on the lower arm of LG8 in the SA27063 × SA3054 map. rnpm2 explained 29.6% of the phenotypic variance and was fine mapped to a 0.8 cM interval between markers h2_16a6a and h2_21h11d. rnpm1 is tightly linked to a cluster of Toll/Interleukin1 receptor-nucleotide binding site-leucine-rich repeat (TIR-NBS-LRR genes and disease resistance protein-like genes, while no resistance gene analogues (RGAs are apparent in the genomic sequence of the reference accession A17 at the

  16. Non-nodulated bacterial leaf symbiosis promotes the evolutionary success of its host plants in the coffee family (Rubiaceae).

    Science.gov (United States)

    Verstraete, Brecht; Janssens, Steven; Rønsted, Nina

    2017-08-01

    Every plant species on Earth interacts in some way or another with microorganisms and it is well known that certain forms of symbiosis between different organisms can drive evolution. Within some clades of Rubiaceae (coffee family), a specific plant-bacteria interaction exists in which non-pathological endophytes are present in the leaves of their hosts. It is hypothesized that the bacterial endophytes, either alone or by interacting with the host, provide chemical protection against herbivory or pathogens by producing toxic or otherwise advantageous secondary metabolites. If the bacteria indeed have a direct beneficial influence on their hosts, it is reasonable to assume that the endophytes may increase the fitness of their hosts and therefore it is probable that their presence also has an influence on the long-term evolution of the particular plant lineages. In this study, the possible origin in time of non-nodulated bacterial leaf symbiosis in the Vanguerieae tribe of Rubiaceae is elucidated and dissimilarities in evolutionary dynamics between species with endophytes versus species without are investigated. Bacterial leaf symbiosis is shown to have most probably originated in the Late Miocene, a period when the savannah habitat is believed to have expanded on the African continent and herbivore pressure increased. The presence of bacterial leaf endophytes appears to be restricted to Old World lineages so far. Plant lineages with leaf endophytes show a significantly higher speciation rate than plant lineages without endophytes, while there is only a small difference in extinction rate. The transition rate shows that evolving towards having endophytes is twice as fast as evolving towards not having endophytes, suggesting that leaf symbiosis must be beneficial for the host plants. We conclude that the presence of bacterial leaf endophytes may also be an important driver for speciation of host plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Alternaria Leaf Spot on Mealycup Sage (Salvia farinacea Benth.) Caused by Alternaria alternata (Fr.) Keissler

    OpenAIRE

    Hiromitsu, NEGISHI; Kazuo, SUYAMA; Faculty of Agriculture,Tokyo University of Agriculture; Faculty of Agriculture,Tokyo University of Agriculture

    2002-01-01

    In June 1995, a disease causing round to irregular-shaped, water-soaked, brown to blackish brown spots on mealycup sage (Salvia farinacea Benth.) was found in Atsugi-shi, Kanagawa Prefecture, Japan. The symptoms were seen only on leaves, not on neither flower petals or stems. The disease was also found in Setagaya-ku, Tokyo, Memambetsu-cho, Hokkaido and Shimoda-shi and Matsuzaki-cho, Shizuoka. An Alternaria sp. was frequently isolated from these diseased plants. The isolates were severely pat...

  18. Impact of solar radiation exposure on phyllosphere bacterial community of red-pigmented baby leaf lettuce.

    Science.gov (United States)

    Truchado, Pilar; Gil, M Isabel; Reboleiro, Patricia; Rodelas, Belén; Allende, Ana

    2017-09-01

    Solar radiation has been identified as a stress factor affecting phyllosphere associated bacteria colonization and survival during primary production. In the present study, the impact of different solar radiation doses on the phyllosphere microbiota of red-pigmented baby leaf lettuce cultivated in open field under commercial conditions was evaluated. Four weeks before harvest, the growing field was divided into four plots; each one was consecutively covered with one-week-interval with a light-excluding plastic to reduce the sunlight exposure. Four different solar radiation treatments were generated and cumulative photosynthetically active radiation (PAR) was used to differentiate treatments as follows: 4889 ± 428 μmol/m 2 /s (uncovered), 4265 ± 356 μmol/m 2 /s (covered for 1 week), 3602 ± 225 μmol/m 2 /s (covered for 2 weeks) and 3115 ± 313 μmol/m 2 /s (covered for 3 weeks). The size and composition of the phyllosphere bacterial community were determined by cultivation-depended (plate count) and independent (qPCR) techniques. Exposure to decreased levels of cumulative PAR did not produce significant differences in total bacterial community size, regardless of the chosen quantification techniques. However, total bacteria size quantified by qPCR was around 3.5 orders of magnitude higher than those obtained by plate count. The observed differences between cultivation-depended and independent techniques could be attributed to the presence of non-viable or viable but non-culturable (VBNC) bacteria. The bacterial community structure was analyzed using temperature gradient gel electrophoresis (TGGE), and significant differences were detected when the four solar treatment were compared. A qPCR approach was applied to the quantification of specific bacterial phyla and classes, previously identified in the phyllosphere of plants available literature, confirming that Proteobacteria, Bacteroidetes, Actinobacterias and Firmicutes were the most abundantly

  19. Genetic analysis of the induced mutants of rice resistant to bacterial leaf blight

    International Nuclear Information System (INIS)

    Nakai, H.

    1990-01-01

    Full text: Seeds of the rice cultivar 'Harebare', which is susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons, gamma-rays, ethyleneimine and ethylmethane-sulfonate. In the M2, plants with better resistance to BLB were identified through inoculation at the seedling and the flag leaf stages with an isolate (T7174) of the Japanese differential race I. Several mutant lines resistant to BLB were selected through tests of the M 3 or M 4 lines derived from selected resistant M 2 plants. The frequency of resistant mutants was significantly higher after the thermal neutron treatment than after treatments with other mutagens. Two mutants, which originated from the neutron treatment, showing a highly quantitative resistance to multiple BLB races were analysed for gene(s) for resistance. The resistance of one of them (M41) to the Japanese races I, II, III, IV, and V was found to be conditioned by a single recessive gene. Three other recessive genes for resistance are known, but their reaction to differential races is different. Therefore, this gene was thought to be new and was tentatively designated as xa-nm(t). The resistance of another mutant (M57) was found to be polygenically inherited. (author)

  20. Effects of forest management practices in temperate beech forests on bacterial and fungal communities involved in leaf litter degradation.

    Science.gov (United States)

    Purahong, Witoon; Kapturska, Danuta; Pecyna, Marek J; Jariyavidyanont, Katalee; Kaunzner, Jennifer; Juncheed, Kantida; Uengwetwanit, Tanaporn; Rudloff, Renate; Schulz, Elke; Hofrichter, Martin; Schloter, Michael; Krüger, Dirk; Buscot, François

    2015-05-01

    Forest management practices (FMPs) significantly influence important ecological processes and services in Central European forests, such as leaf litter decomposition and nutrient cycling. Changes in leaf litter diversity, and thus, its quality as well as microbial community structure and function induced by different FMPs were hypothesized to be the main drivers causing shifts in decomposition rates and nutrient release in managed forests. In a litterbag experiment lasting 473 days, we aimed to investigate the effects of FMPs (even-aged timber management, selective logging and unmanaged) on bacterial and fungal communities involved in leaf litter degradation over time. Our results showed that microbial communities in leaf litter were strongly influenced by both FMPs and sampling date. The results from nonmetric multidimensional scaling (NMDS) ordination revealed distinct patterns of bacterial and fungal successions over time in leaf litter. We demonstrated that FMPs and sampling dates can influence a range of factors, including leaf litter quality, microbial macronutrients, and pH, which significantly correlate with microbial community successions.

  1. Evaluation of assembling methods on determination of whole genome sequence of Xylella fastidiosa blueberry bacterial leaf scorch strain

    Science.gov (United States)

    Blueberry bacterial leaf scorch (BBLS) disease, a threat to blueberry production in the Southern USA and potentially elsewhere, is caused by Xylella fastidiosa. Efficient control of BBLS requires knowledge of the pathogen. However, this is challenging because Xylella fastidiosa is difficult to cultu...

  2. Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis

    Directory of Open Access Journals (Sweden)

    Abdjad Asih Nawangsih

    2011-04-01

    Full Text Available Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis. X. oryzae pv. oryzae (Xoo causes bacterial leaf blight (BLB of rice (Oryza sativa L., a major disease that constrains production of the staple crop in many countries of the world. Identification of X. oryzae pv. oryzae (Xoo was conducted based on the disease symptoms, pathogenicity, morphological, physiological, and genetic characteristics of bacterial cultures isolated from the infected plants. Fifty bacterial isolates predicted as Xoo have been successfully isolated. They are aerobic, rod shaped, and Gram negative bacteria. The isolates were evaluated for their hypersensitivity in tobacco and pathogenicity in rice plant. Fifty isolates induced hypersensitive reaction in tobacco and showed pathogenicity symptom in rice in different length. Based on physiological test, hypersensitivity and pathogenicity reactions, three bacterial isolates strongly predicted as Xoo, i.e. STG21, STG42, and STG46, were non indole formation, non pigment fluorescent, hydrolyzed casein, catalase activity positive, but negative oxidase. Partial sequencing of 16S rRNA genes of STG21 and STG42 showed 80% and 82% homology with X. oryzae, respectively, while STG46 showed 84% homology with X. campestris. Mini-Tn5 transposon mutagenesis of STG21 generated one of the mutants (M5 lossed it’s ability to induce hypersensitive reaction in tobacco plant and deficient in pathogenicity on rice. The lesion length of rice leaf caused by the mutant M5 decreased up to 80%.

  3. Transcriptome Analysis of Poplar during Leaf Spot Infection with Sphaerulina spp.

    Directory of Open Access Journals (Sweden)

    Adam J Foster

    Full Text Available Diseases of poplar caused by the native fungal pathogen Sphaerulina musiva and related species are of growing concern, particularly with the increasing interest in intensive poplar plantations to meet growing energy demands. Sphaerulina musiva is able to cause infection on leaves, resulting in defoliation and canker formation on stems. To gain a greater understanding of the different responses of poplar species to infection caused by the naturally co-evolved Sphaerulina species, RNA-seq was conducted on leaves of Populus deltoides, P. balsamifera and P. tremuloides infected with S. musiva, S. populicola and a new undescribed species, Ston1, respectively. The experiment was designed to contain the pathogen in a laboratory environment, while replicating disease development in commercial plantations. Following inoculation, trees were monitored for disease symptoms, pathogen growth and host responses. Genes involved in phenylpropanoid, terpenoid and flavonoid biosynthesis were generally upregulated in P. balsamifera and P. tremuloides, while cell wall modification appears to play an important role in the defense of P. deltoides. Poplar defensive genes were expressed early in P. balsamifera and P. tremuloides, but their expression was delayed in P. deltoides, which correlated with the rate of disease symptoms development. Also, severe infection in P. balsamifera led to leaf abscission. This data gives an insight into the large differences in timing and expression of genes between poplar species being attacked by their associated Sphaerulina pathogen.

  4. Genetic characterization and linkage disequilibrium mapping of resistance to gray leaf spot in maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Liyu Shi

    2014-04-01

    Full Text Available Gray leaf spot (GLS, caused by Cercospora zeae-maydis, is an important foliar disease of maize (Zea mays L. worldwide, resistance to which is controlled by multiple quantitative trait loci (QTL. To gain insights into the genetic architecture underlying the resistance to this disease, an association mapping population consisting of 161 inbred lines was evaluated for resistance to GLS in a plant pathology nursery at Shenyang in 2010 and 2011. Subsequently, a genome-wide association study, using 41,101 single-nucleotide polymorphisms (SNPs, identified 51 SNPs significantly (P < 0.001 associated with GLS resistance, which could be converted into 31 QTL. In addition, three candidate genes related to plant defense were identified, including nucleotide-binding-site/leucine-rich repeat, receptor-like kinase genes similar to those involved in basal defense. Two genic SNPs, PZE-103142893 and PZE-109119001, associated with GLS resistance in chromosome bins 3.07 and 9.07, can be used for marker-assisted selection (MAS of GLS resistance. These results provide an important resource for developing molecular markers closely linked with the target trait, enhancing breeding efficiency.

  5. Evaluation of the Incidence and Severity of Olive Leaf Spot caused by Spilocaea oleaginain different olive cultivars in Palestine

    Directory of Open Access Journals (Sweden)

    Ruba Abuamsha

    2013-12-01

    Full Text Available Twelve olive (Olea europaea L. cultivars including Nabali Baladi, Nabali Mohassan, Santa Augustino, Nasohi Jaba`a 1, Nasohi Jaba`a 2, Yunani, Talmasani, Chemlali, Arbequino, Frantoio, Coca and Barouni, were sampled for their susceptibility to Spilocaea oleagina the causal agent for Olive leaf spot (OLS disease on olive trees in Palestine. Investigations were carried out to measure the incidence and severity of the disease at Qabatyia station in Jenin district area Susceptible olive cultivars grown commercially in Palestine include Arbequino, Frantoio and ?Barouni’.The “Nabali” is the most dominant and highly susceptible olive cultivar grown in Palestine. Disease incidence varied greatly among the cultivars F=59.4, df=11, 251, p?0.0001 and was correlated with the severity (y = 0.42x + 9.3, P ? 0.0001, R² = 0.84, y = disease severity and x = disease incidence. Disease severity also varied among different cultivars F=13.9, df=11, 251, p?0.0001. Nabali Mohassan was the most affected susceptible while Barouni was most resistant. Progress of disease severity over time fit the logistic function for all cultivars except for highly susceptible cultivars F=1.56, df=6, 83, p?0.169. The assessment method may be useful to screen olive cultivars for OLS resistance in Palestine.

  6. Fine mapping of a quantitative resistance gene for gray leaf spot of maize (Zea mays L.) derived from teosinte (Z. mays ssp. parviglumis).

    Science.gov (United States)

    Zhang, Xinye; Yang, Qin; Rucker, Elizabeth; Thomason, Wade; Balint-Kurti, Peter

    2017-06-01

    In this study we mapped the QTL Qgls8 for gray leaf spot (GLS) resistance in maize to a ~130 kb region on chromosome 8 including five predicted genes. In previous work, using near isogenic line (NIL) populations in which segments of the teosinte (Zea mays ssp. parviglumis) genome had been introgressed into the background of the maize line B73, we had identified a QTL on chromosome 8, here called Qgls8, for gray leaf spot (GLS) resistance. We identified alternate teosinte alleles at this QTL, one conferring increased GLS resistance and one increased susceptibility relative to the B73 allele. Using segregating populations derived from NIL parents carrying these contrasting alleles, we were able to delimit the QTL region to a ~130 kb (based on the B73 genome) which encompassed five predicted genes.

  7. Leaf-associated bacterial microbiota of coffee and its correlation with manganese and calcium levels on leaves

    Directory of Open Access Journals (Sweden)

    Leandro Pio de Sousa

    2018-05-01

    Full Text Available Abstract Coffee is one of the most valuable agricultural commodities and the plants’ leaves are the primary site of infection for most coffee diseases, such as the devastating coffee leaf rust. Therefore, the use of bacterial microbiota that inhabits coffee leaves to fight infections could be an alternative agricultural method to protect against coffee diseases. Here, we report the leaf-associated bacteria in three coffee genotypes over the course of a year, with the aim to determine the diversity of bacterial microbiota. The results indicate a prevalence of Enterobacteriales in Coffea canephora, Pseudomonadales in C. arabica ‘Obatã’, and an intriguing lack of bacterial dominance in C. arabica ‘Catuaí’. Using PERMANOVA analyses, we assessed the association between bacterial abundance in the coffee genotypes and environmental parameters such as temperature, precipitation, and mineral nutrients in the leaves. We detected a close relationship between the amount of Mn and the abundance of Pseudomonadales in ‘Obatã’ and the amount of Ca and the abundance of Enterobacteriales in C. canephora. We suggest that mineral nutrients can be key drivers that shape leaf microbial communities.

  8. Leaf-associated bacterial microbiota of coffee and its correlation with manganese and calcium levels on leaves.

    Science.gov (United States)

    de Sousa, Leandro Pio de; da Silva, Marcio José da; Mondego, Jorge Maurício

    2018-05-17

    Coffee is one of the most valuable agricultural commodities and the plants' leaves are the primary site of infection for most coffee diseases, such as the devastating coffee leaf rust. Therefore, the use of bacterial microbiota that inhabits coffee leaves to fight infections could be an alternative agricultural method to protect against coffee diseases. Here, we report the leaf-associated bacteria in three coffee genotypes over the course of a year, with the aim to determine the diversity of bacterial microbiota. The results indicate a prevalence of Enterobacteriales in Coffea canephora, Pseudomonadales in C. arabica 'Obatã', and an intriguing lack of bacterial dominance in C. arabica 'Catuaí'. Using PERMANOVA analyses, we assessed the association between bacterial abundance in the coffee genotypes and environmental parameters such as temperature, precipitation, and mineral nutrients in the leaves. We detected a close relationship between the amount of Mn and the abundance of Pseudomonadales in 'Obatã' and the amount of Ca and the abundance of Enterobacteriales in C. canephora. We suggest that mineral nutrients can be key drivers that shape leaf microbial communities.

  9. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection

    DEFF Research Database (Denmark)

    Ernstsen, Christina Lundgaard; Login, Frédéric H.; Jensen, Helene Halkjær

    2017-01-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacteria...

  10. TLC profiles and antibacterial activity of Glinus oppositifolius L. Aug. DC. (Molluginaceae leaf and stem extracts against bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Juliana Janet R. Martin-Puzon

    2015-07-01

    Full Text Available Objective: To determine the antibacterial activities and the thin-layer chromatography (TLC fingerprint profiles of leaf and stem extracts of Glinus oppositifolius L. Aug. DC (G. oppositifolius. Methods: The leaves and stems were extracted using chloroform, ethanol and methanol as solvents. The antibacterial activity of the extracts were evaluated through disc diffusion, minimum inhibitory concentration and bactericidal concentration assays against methicillinresistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended spectrum β-lactamase-producing, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamaseproducing Pseudomonas aeruginosa (P. aeruginosa and Acinetobacter baumanii (A. baumanii. The TLC separation was carried out on leaf and stem ethanol extracts in ethyl acetate: n-hexane solvent system. Distinct spots were examined under visible light, UV 254 nm, UV 366 nm and after spraying with vanillin-sulfuric acid. Results: The leaf extracts revealed antibacterial activities, inhibiting the growth of the nonresistant and multidrug-resistant strains of the Gram-negative bacteria Escherichia coli, P. aeruginosa and A. baumanii. The TLC fingerprint profiles demonstrated the presence of various phytochemicals in leaf and stem extracts. Leaf extracts exhibited more diverse constituents compared to stem extracts, but some constituents were similar in both plant parts. Conclusions: G. oppositifolius leaf extracts can be used as new, alternative sources of antimicrobials against non-resistant and multidrug-resistant strains of the Gram-negative bacteria Escherichia coli, P. aeruginosa and A. baumanii. The TLC profiles represent the chemical integrity of G. oppositifolius leaf and stem extracts which form an important and powerful tool for standardization, authentication, quality control and determination of bioactive components of G. oppositifolius in any formulation and in powder form.

  11. Influences of Plant Species, Season and Location on Leaf Endophytic Bacterial Communities of Non-Cultivated Plants.

    Science.gov (United States)

    Ding, Tao; Melcher, Ulrich

    2016-01-01

    Bacteria are known to be associated endophytically with plants. Research on endophytic bacteria has identified their importance in food safety, agricultural production and phytoremediation. However, the diversity of endophytic bacterial communities and the forces that shape their compositions in non-cultivated plants are largely uncharacterized. In this study, we explored the diversity, community structure, and dynamics of endophytic bacteria in different plant species in the Tallgrass Prairie Preserve of northern Oklahoma, USA. High throughput sequencing of amplified segments of bacterial rDNA from 81 samples collected at four sampling times from five plant species at four locations identified 335 distinct OTUs at 97% sequence similarity, representing 16 phyla. Proteobacteria was the dominant phylum in the communities, followed by the phyla Bacteriodetes and Actinobacteria. Bacteria from four classes of Proteobacteria were detected with Alphaproteobacteria as the dominant class. Analysis of molecular variance revealed that host plant species and collecting date had significant influences on the compositions of the leaf endophytic bacterial communities. The proportion of Alphaproteobacteria was much higher in the communities from Asclepias viridis than from other plant species and differed from month to month. The most dominant bacterial groups identified in LDA Effect Size analysis showed host-specific patterns, indicating mutual selection between host plants and endophytic bacteria and that leaf endophytic bacterial compositions were dynamic, varying with the host plant's growing season in three distinct patterns. In summary, next generation sequencing has revealed variations in the taxonomic compositions of leaf endophytic bacterial communities dependent primarily on the nature of the plant host species.

  12. Influences of Plant Species, Season and Location on Leaf Endophytic Bacterial Communities of Non-Cultivated Plants.

    Directory of Open Access Journals (Sweden)

    Tao Ding

    Full Text Available Bacteria are known to be associated endophytically with plants. Research on endophytic bacteria has identified their importance in food safety, agricultural production and phytoremediation. However, the diversity of endophytic bacterial communities and the forces that shape their compositions in non-cultivated plants are largely uncharacterized. In this study, we explored the diversity, community structure, and dynamics of endophytic bacteria in different plant species in the Tallgrass Prairie Preserve of northern Oklahoma, USA. High throughput sequencing of amplified segments of bacterial rDNA from 81 samples collected at four sampling times from five plant species at four locations identified 335 distinct OTUs at 97% sequence similarity, representing 16 phyla. Proteobacteria was the dominant phylum in the communities, followed by the phyla Bacteriodetes and Actinobacteria. Bacteria from four classes of Proteobacteria were detected with Alphaproteobacteria as the dominant class. Analysis of molecular variance revealed that host plant species and collecting date had significant influences on the compositions of the leaf endophytic bacterial communities. The proportion of Alphaproteobacteria was much higher in the communities from Asclepias viridis than from other plant species and differed from month to month. The most dominant bacterial groups identified in LDA Effect Size analysis showed host-specific patterns, indicating mutual selection between host plants and endophytic bacteria and that leaf endophytic bacterial compositions were dynamic, varying with the host plant's growing season in three distinct patterns. In summary, next generation sequencing has revealed variations in the taxonomic compositions of leaf endophytic bacterial communities dependent primarily on the nature of the plant host species.

  13. The Bacterial Pathogen Xylella fastidiosa Affects the Leaf Ionome of Plant Hosts during Infection

    Science.gov (United States)

    De La Fuente, Leonardo; Parker, Jennifer K.; Oliver, Jonathan E.; Granger, Shea; Brannen, Phillip M.; van Santen, Edzard; Cobine, Paul A.

    2013-01-01

    Xylella fastidiosa is a plant pathogenic bacterium that lives inside the host xylem vessels, where it forms biofilm believed to be responsible for disrupting the passage of water and nutrients. Here, Nicotiana tabacum was infected with X. fastidiosa, and the spatial and temporal changes in the whole-leaf ionome (i.e. the mineral and trace element composition) were measured as the host plant transitioned from healthy to diseased physiological status. The elemental composition of leaves was used as an indicator of the physiological changes in the host at a specific time and relative position during plant development. Bacterial infection was found to cause significant increases in concentrations of calcium prior to the appearance of symptoms and decreases in concentrations of phosphorous after symptoms appeared. Field-collected leaves from multiple varieties of grape, blueberry, and pecan plants grown in different locations over a four-year period in the Southeastern US showed the same alterations in Ca and P. This descriptive ionomics approach characterizes the existence of a mineral element-based response to X. fastidiosa using a model system suitable for further manipulation to uncover additional details of the role of mineral elements during plant-pathogen interactions. This is the first report on the dynamics of changes in the ionome of the host plant throughout the process of infection by a pathogen. PMID:23667547

  14. The bacterial pathogen Xylella fastidiosa affects the leaf ionome of plant hosts during infection.

    Directory of Open Access Journals (Sweden)

    Leonardo De La Fuente

    Full Text Available Xylella fastidiosa is a plant pathogenic bacterium that lives inside the host xylem vessels, where it forms biofilm believed to be responsible for disrupting the passage of water and nutrients. Here, Nicotiana tabacum was infected with X. fastidiosa, and the spatial and temporal changes in the whole-leaf ionome (i.e. the mineral and trace element composition were measured as the host plant transitioned from healthy to diseased physiological status. The elemental composition of leaves was used as an indicator of the physiological changes in the host at a specific time and relative position during plant development. Bacterial infection was found to cause significant increases in concentrations of calcium prior to the appearance of symptoms and decreases in concentrations of phosphorous after symptoms appeared. Field-collected leaves from multiple varieties of grape, blueberry, and pecan plants grown in different locations over a four-year period in the Southeastern US showed the same alterations in Ca and P. This descriptive ionomics approach characterizes the existence of a mineral element-based response to X. fastidiosa using a model system suitable for further manipulation to uncover additional details of the role of mineral elements during plant-pathogen interactions. This is the first report on the dynamics of changes in the ionome of the host plant throughout the process of infection by a pathogen.

  15. New Generation of Resistant Sugar Beet Varieties for Advanced Integrated Management of Cercospora Leaf Spot in Central Europe.

    Science.gov (United States)

    Vogel, Johannes; Kenter, Christine; Holst, Carsten; Märländer, Bernward

    2018-01-01

    Cercospora leaf spot (CLS) epidemics in sugar beet have been increasing in recent years causing higher use of fungicides. Concomitantly, the availability of effective fungicides is at risk because of resistance development in the fungus, the lack of new active ingredients as well as restrictive approval practices. A key option for an integrated management of CLS is cultivation of resistant varieties. Because of the yield penalty in resistant varieties, acceptance in commercial practice so far has been low. The aim of our study was to characterize recent sugar beet varieties registered in Germany in terms of resistance and tolerance to CLS and their value for integrated pest management. The genetic basis of CLS resistance in varieties is protected by intellectual property rights even after variety registration and not open to the public due to economic competition. To gain reliable data for cultivation, varieties have to be tested for their resistance traits under field conditions at varying levels of infection with Cercospora beticola . In collaboration with variety related stakeholders, 15 sugar beet varieties were tested in 49 field trials in Germany from 2014 to 2016 for their yield response to CLS. The trials were set up in a split-plot design with and without infection (i.e., with and without fungicide). The classification of varietal reaction to CLS is based on symptomatic leaf area (susceptibility) and the resulting relative yield loss (tolerance). Since the relation between both parameters varied among varieties, it was used as an additional parameter to describe tolerance. On this basis, three groups of varieties were identified. They can be characterized as a susceptible, a resistant and a presumably tolerant cluster. A comparison of the data with an older dataset originating from 2009 to 2011 revealed that yield performance of recent varieties with resistance to C. beticola caught up with susceptible varieties due to breeding progress. They showed no

  16. Topography and crop management are key factors for the development of american leaf spot epidemics on coffee in costa rica.

    Science.gov (United States)

    Avelino, Jacques; Cabut, Sandrine; Barboza, Bernardo; Barquero, Miguel; Alfaro, Ronny; Esquivel, César; Durand, Jean-François; Cilas, Christian

    2007-12-01

    ABSTRACT We monitored the development of American leaf spot of coffee, a disease caused by the gemmiferous fungus Mycena citricolor, in 57 plots in Costa Rica for 1 or 2 years in order to gain a clearer understanding of conditions conducive to the disease and improve its control. During the investigation, characteristics of the coffee trees, crop management, and the environment were recorded. For the analyses, we used partial least-squares regression via the spline functions (PLSS), which is a nonlinear extension to partial least-squares regression (PLS). The fungus developed well in areas located between approximately 1,100 and 1,550 m above sea level. Slopes were conducive to its development, but eastern-facing slopes were less affected than the others, probably because they were more exposed to sunlight, especially in the rainy season. The distance between planting rows, the shade percentage, coffee tree height, the type of shade, and the pruning system explained disease intensity due to their effects on coffee tree shading and, possibly, on the humidity conditions in the plot. Forest trees and fruit trees intercropped with coffee provided particularly propitious conditions. Apparently, fertilization was unfavorable for the disease, probably due to dilution phenomena associated with faster coffee tree growth. Finally, series of wet spells interspersed with dry spells, which were frequent in the middle of the rainy season, were critical for the disease, probably because they affected the production and release of gemmae and their viability. These results could be used to draw up a map of epidemic risks taking topographical factors into account. To reduce those risks and improve chemical control, our results suggested that farmers should space planting rows further apart, maintain light shading in the plantation, and prune their coffee trees.

  17. Code-assisted discovery of TAL effector targets in bacterial leaf streak of rice reveals contrast with bacterial blight and a novel susceptibility gene.

    Directory of Open Access Journals (Sweden)

    Raul A Cernadas

    2014-02-01

    Full Text Available Bacterial leaf streak of rice, caused by Xanthomonas oryzae pv. oryzicola (Xoc is an increasingly important yield constraint in this staple crop. A mesophyll colonizer, Xoc differs from X. oryzae pv. oryzae (Xoo, which invades xylem to cause bacterial blight of rice. Both produce multiple distinct TAL effectors, type III-delivered proteins that transactivate effector-specific host genes. A TAL effector finds its target(s via a partially degenerate code whereby the modular effector amino acid sequence identifies nucleotide sequences to which the protein binds. Virulence contributions of some Xoo TAL effectors have been shown, and their relevant targets, susceptibility (S genes, identified, but the role of TAL effectors in leaf streak is uncharacterized. We used host transcript profiling to compare leaf streak to blight and to probe functions of Xoc TAL effectors. We found that Xoc and Xoo induce almost completely different host transcriptional changes. Roughly one in three genes upregulated by the pathogens is preceded by a candidate TAL effector binding element. Experimental analysis of the 44 such genes predicted to be Xoc TAL effector targets verified nearly half, and identified most others as false predictions. None of the Xoc targets is a known bacterial blight S gene. Mutational analysis revealed that Tal2g, which activates two genes, contributes to lesion expansion and bacterial exudation. Use of designer TAL effectors discriminated a sulfate transporter gene as the S gene. Across all targets, basal expression tended to be higher than genome-average, and induction moderate. Finally, machine learning applied to real vs. falsely predicted targets yielded a classifier that recalled 92% of the real targets with 88% precision, providing a tool for better target prediction in the future. Our study expands the number of known TAL effector targets, identifies a new class of S gene, and improves our ability to predict functional targeting.

  18. Leaf-morphology-assisted selection for resistance to two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in carnations (Dianthus caryophyllus L).

    Science.gov (United States)

    Seki, Kousuke

    2016-10-01

    The development of a cultivar resistant to the two-spotted spider mite has provided both ecological and economic benefits to the production of cut flowers. This study aimed to clarify the mechanism of resistance to mites using an inbred population of carnations. In the resistant and susceptible plants selected from an inbred population, a difference was recognised in the thickness of the abaxial palisade tissue by microscopic examination of the damaged leaf. Therefore, it was assumed that mites displayed feeding preferences within the internal leaf structure of the carnation leaf. The suitability of the host plant for mites was investigated using several cultivars selected using an index of the thickness from the abaxial leaf surface to the spongy tissue. The results suggested that the cultivar associated with a thicker abaxial tissue lowered the intrinsic rate of natural increase of the mites. The cultivars with a thicker abaxial tissue of over 120 µm showed slight damage in the field test. The ability of mites to feed on the spongy tissue during an early life stage from hatching to adult emergence was critical. It was possible to select a cultivar that is resistant to mites under a real cultivation environment by observing the internal structure of the leaf. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. First report in Ghana of #Xanthomonas citri# pv. #mangiferaeindicae# causing mango bacterial canker on #Mangifera indica#

    OpenAIRE

    Pruvost, Olivier; Boyer, Claudine; Vital, Karine; Gagnevin, Lionel; De Bruno Austin, L.; Rey, Jean-Yves

    2011-01-01

    Bacterial canker of mango (or bacterial black spot), caused by Xanthomonas citri pv. mangiferaeindicae, is an economically important disease in tropical and subtropical producing areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Several months after infection, leaf lesions dry and turn light brown or ash gray. Severe leaf infection may result in abscission. F...

  20. Efficacy of fresh leaf extracts of Spondias mombin against some clinical bacterial isolates from typhoid patients

    Directory of Open Access Journals (Sweden)

    Olukemi Aromolaran

    2014-12-01

    Full Text Available Objective: To evaluate the phytochemical properties and antibacterial activity of methanol, acetone, ethanol and aqueous extracts of fresh leaves of Spondias mombin (S. mombin on some clinical bacterial isolates. Methods: Clean and fresh leaves of S. mombin were collected in Ondo, Southwestern Nigeria. The leaves were blended, extracted with methanol, acetone, ethanol and water. The extracts were evaporated to dryness using rotary evaporator and tested for the presence of saponins, tannins, cardiac glycoside, terpenoids, flavonoids, reducing sugars, volatile oils, alkaloids and glycoside. The extract were tested against Gram-negative bacteria Klebsiella pneumonia, Serratia marcescens, Salmonella typhi and Enterobacter aerogens; Gram-positive bacteria Staphylococcus aureus by observing the zones of inhibition using agar well diffusion assay. Results: The study showed that the leaves contained saponins, tannins, flavonoids, alkaloids and glycoside. All the solvent extracts showed activity against all the test bacteria. The methanol extract also showed the highest activity against Enterobacter aerogens, zone of diameter (15.00 依1.89 mm, while the ethanol extract showed the highest activity against Staphylococcus aureus with zone of diameter (12.50依1.50 mm. The acetone extract showed the highest activity against Salmonella typhi, zone of diameter (17.50依0.29 mm followed by methanol extract showing zone of diameter (15.67依1.01 mm. The acetone extract showed the highest activity against Klebsiella pneumonia (15.17依0.67 mm, while the aqueous extract shows the highest activity against Serratia marcescens (14.67依2.68 mm. The minimum inhibitory concentration of the leaf extracts ranged between 10-90 mg/mL. Conclusions: This study showed that the aqueous and organic solvents extract of fresh leaves of S. mombin has anti-microbial activity against all the tested organisms.

  1. Endophytic Streptomyces spp. as Biocontrol Agents of Rice Bacterial Leaf Blight Pathogen (Xanthomonas oryzae pv. oryzae

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    RATIH DEWI HASTUTI

    2012-12-01

    Full Text Available Xanthomonas oryzae pv. oryzae (Xoo, a causal agent of bacterial leaf blight (BLB, is one of the most important pathogens of rice. The effectiveness of ten Streptomyces spp. isolates in suppressing Xoo disease was assessed in planta and in vitro. In planta experiments were carried out in a greenhouse and arranged in a randomized completely block design (RCBD with three replications. Twenty treatments were tested which included plants inoculated with both Streptomyces spp. and Xoo, and plants inoculated with only Streptomyces spp. Plants inoculated with Xoo and sprayed with a chemical bactericide, and plants inoculated with only Xoo served as positive controls, whereas plants not inoculated with either Streptomyces spp. or Xoo were used as negative controls. The results showed that the effect of endophytic Streptomyces spp. on BLB disease expressed as area under disease progress curve (AUDPC was not significantly different to that on control plants (P > 0.05. However, plants inoculated with endophytic Streptomyces spp. were significantly taller and produced higher tiller number than control plants (P < 0.05. Streptomyces spp. isolate AB131-1 gave the highest plant height. In vitro studies on biocontrol mechanisms of selected Streptomyces spp. isolates showed that isolate LBR02 gave the highest inhibition activity on Xoo growth, followed by AB131-1 and AB131-2. Two isolates (AB131-1 and LBR02 were able to produce chitinase, phosphatase, and siderophore which included biocontrol characteristics. Morphological and colonization studies under SEM and light microscopy confirmed that the three isolates were endophytic Streptomyces spp. from different species. These studies found that the paddy plant which was inoculated with endophytic Streptomyces spp. AB131-1 and infected by Xoo could increase the height of plant and number of tillers.

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

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    Rajesh Kumari Manhas

    2016-12-01

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

  3. Contribution of the drought tolerance-related Stress-responsive NAC1 transcription factor to resistance of barley to Ramularia leaf spot

    OpenAIRE

    MCGRANN, GRAHAM R D; STEED, ANDREW; BURT, CHRISTOPHER; GODDARD, RACHEL; LACHAUX, CLEA; BANSAL, ANURADHA; CORBITT, MARGARET; GORNIAK, KALINA; NICHOLSON, PAUL; BROWN, JAMES K M

    2014-01-01

    NAC proteins are plant transcription factors that are involved in tolerance to abiotic and biotic stresses, as well as in many developmental processes. Stress-responsive NAC1 (SNAC1) transcription factor is involved in drought tolerance in barley and rice, but has not been shown previously to have a role in disease resistance. Transgenic over-expression of HvSNAC1 in barley cv. Golden Promise reduced the severity of Ramularia leaf spot (RLS), caused by the fungus Ramularia collo-cygni, but ha...

  4. Pathovars of Pseudomonas syringae Causing Bacterial Brown Spot and Halo Blight in Phaseolus vulgaris L. Are Distinguishable by Ribotyping

    Science.gov (United States)

    González, Ana J.; Landeras, Elena; Mendoza, M. Carmen

    2000-01-01

    Ribotyping was evaluated as a method to differentiate between Pseudomonas syringae pv. phaseolicola and pv. syringae strains causing bacterial brown spot and halo blight diseases in Phaseolus vulgaris L. Ribotyping, with restriction enzymes BglI and SalI and using the Escherichia coli rrnB operon as the probe, differentiated 11 and 14 ribotypes, respectively, and a combination of data from both procedures yielded 19 combined ribotypes. Cluster analysis of the combined ribotypes differentiated the pathovars phaseolicola and syringae, as well as different clonal lineages within these pathovars. The potential of ribotyping to screen for correlations between lineages and factors such as geographical region and/or bean varieties is also reported. PMID:10653764

  5. Characterization of hypersensitive resistance to bacterial spot race T3 (Xanthomonas perforans) from tomato accession PI 128216.

    Science.gov (United States)

    Robbins, Matthew D; Darrigues, Audrey; Sim, Sung-Chur; Masud, Mohammed Abu Taher; Francis, David M

    2009-09-01

    Bacterial spot of tomato is caused by four species of Xanthomonas. The accession PI 128216 (Solanum pimpinellifolium) displays a hypersensitive reaction (HR) to race T3 strains (predominantely Xanthomonas perforans). We developed an inbred backcross (IBC) population (BC(2)S(5), 178 families) derived from PI 128216 and OH88119 (S. lycopersicum) as the susceptible recurrent parent for simultaneous introgression and genetic analysis of the HR response. These IBC families were evaluated in the greenhouse for HR to race T3 strain Xcv761. The IBC population was genotyped with molecular markers distributed throughout the genome in order to identify candidate loci conferring resistance. We treated the IBC population as a hypothesis forming generation to guide validation in subsequent crosses. Nonparametric analysis identified an association between HR and markers clustered on chromosome 11 (P P > 0.002). Further analysis of the IBC population suggested that markers on chromosome 6 and 11 failed to assort independently, a phenomenon known as gametic phase disequilibrium. Therefore, to validate marker-trait linkages, resistant IBC plants were crossed with OH88119 and BC(3)F(2) progeny were evaluated for HR in the greenhouse. In these subsequent populations, the HR response was associated with the chromosome 11 markers (P 0.25). Independent F(2) families were developed by crossing resistant IBC lines to OH8245, OH88119, and OH7530. These populations were genotyped, organized into classes based on chromosome 11 markers, and evaluated for resistance in the field. The PI 128216 locus on chromosome 11 provided resistance that was dependent on gene dosage and genetic background. These results define a single locus, Rx-4, from PI 128216, which provides resistance to bacterial spot race T3, has additive gene action, and is located on chromosome 11.

  6. Identification of Causes of Red Leaf Spot on Red Jabon (Anthocephalus macrophyllus (Roxb. Havil Seeds in Kima Atas Permanent Nursery, Manado Forestry Research Institute

    Directory of Open Access Journals (Sweden)

    Hanif Nurul Hidayah

    2015-12-01

    Full Text Available Fulfillment the needs of Red Jabon (Anthocephalus macrophyllus (Roxb. Havil seeds on the other hand can create an unbalanced ecosystem. The availability of red Jabon seed was becoming a source of food for pests, then it causes an explosion of pests and pathogens. The disease that most often affect red Jabon seeds, both in the nursery and in the field was red leaf spot (antraknose. The initial step to control red leaf spot disease is the identification of causing. Identification method performed by observation of the symptoms in the field, followed by microscopic observation in a laboratory. Based on the identification result, it was known that the disease caused by the fungus Cercospora sp., Colletotrichum sp. and Pestalotia sp. The effect caused by those fungal pathogens was the disruption of the photosynthetic process that ultimately inhibits the growth of red Jabon seeds. The controls which have been done are arranged the watering intensity, isolated the infected seed,and applied the chemical fungicide.

  7. Structure and Origin of Xanthomonas arboricola pv. pruni Populations Causing Bacterial Spot of Stone Fruit Trees in Western Europe.

    Science.gov (United States)

    Boudon, Sylvain; Manceau, Charles; Nottéghem, Jean-Loup

    2005-09-01

    ABSTRACT Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot on stone fruit, was found in 1995 in several orchards in southeastern France. We studied population genetics of this emerging pathogen in comparison with populations from the United States, where the disease was first described, and from Italy, where the disease has occurred since 1920. Four housekeeping genes (atpD, dnaK, efp, and glnA) and the intergenic transcribed spacer region were sequenced from a total of 3.9 kb of sequences, and fluorescent amplified fragment length polymorphism (FAFLP) analysis was performed. A collection of 64 X. arboricola pv. pruni strains, including 23 strains from France, was analyzed. The X. arboricola pv. pruni population had a low diversity because no sequence polymorphisms were observed. Population diversity revealed by FAFLP was lower for the West European population than for the American population. The same bacterial genotype was detected from five countries on three continents, a geographic distribution that can be explained by human-aided migration of bacteria. Our data support the hypothesis that the pathogen originated in the United States and subsequently has been disseminated to other stone-fruit-growing regions of the world. In France, emergence of this disease was due to a recent introduction of the most prevalent genotype of the bacterium found worldwide.

  8. The Intestinal Eukaryotic and Bacterial Biome of Spotted Hyenas: The Impact of Social Status and Age on Diversity and Composition.

    Science.gov (United States)

    Heitlinger, Emanuel; Ferreira, Susana C M; Thierer, Dagmar; Hofer, Heribert; East, Marion L

    2017-01-01

    In mammals, two factors likely to affect the diversity and composition of intestinal bacteria (bacterial microbiome) and eukaryotes (eukaryome) are social status and age. In species in which social status determines access to resources, socially dominant animals maintain better immune processes and health status than subordinates. As high species diversity is an index of ecosystem health, the intestinal biome of healthier, socially dominant animals should be more diverse than those of subordinates. Gradual colonization of the juvenile intestine after birth predicts lower intestinal biome diversity in juveniles than adults. We tested these predictions on the effect of: (1) age (juvenile/adult) and (2) social status (low/high) on bacterial microbiome and eukaryome diversity and composition in the spotted hyena ( Crocuta crocuta ), a highly social, female-dominated carnivore in which social status determines access to resources. We comprehensively screened feces from 35 individually known adult females and 7 juveniles in the Serengeti ecosystem for bacteria and eukaryotes, using a set of 48 different amplicons (4 for bacterial 16S, 44 for eukaryote 18S) in a multi-amplicon sequencing approach. We compared sequence abundances to classical coprological egg or oocyst counts. For all parasite taxa detected in more than six samples, the number of sequence reads significantly predicted the number of eggs or oocysts counted, underscoring the value of an amplicon sequencing approach for quantitative measurements of parasite load. In line with our predictions, our results revealed a significantly less diverse microbiome in juveniles than adults and a significantly higher diversity of eukaryotes in high-ranking than low-ranking animals. We propose that free-ranging wildlife can provide an intriguing model system to assess the adaptive value of intestinal biome diversity for both bacteria and eukaryotes.

  9. Testing the 'hybrid susceptibility' and 'phenological sink' hypotheses using the P. balsamifera - P. deltoides hybrid zone and septoria leaf spot [Septoria musiva].

    Science.gov (United States)

    LeBoldus, Jared M; Isabel, Nathalie; Floate, Kevin D; Blenis, Peter; Thomas, Barb R

    2013-01-01

    Hybrid genotypes that arise between plant species frequently have increased susceptibility to arthropod pests and fungal pathogens. This pattern has been attributed to the breakdown of plant defenses ('Hybrid susceptibility' hypothesis) and (or) to extended periods of susceptibility attributed to plant phenologies in zones of species overlap and (or) hybridization ('phenological sink' hypothesis). We examined these hypotheses by assessing the susceptibility of parental and hybrid Populus host genotypes to a leaf spot disease caused by the fungal pathogen Septoria musiva. For this purpose, 214 genotypes were obtained from morphologically pure zones of P. balsamifera and P. deltoides, and from an intervening zone of overlap and hybridization on the drainage of the Red Deer River, Alberta, Canada. Genotypes were identified as P. balsamifera, P. deltoides, or hybrid using a suite of 27 species-specific SNP markers. Initially the genetic structure of the hybrid zone was characterized with 27.7% of trees classified as admixed individuals. To test the hybrid susceptibility hypothesis, a subset of 52 genotypes was inoculated with four isolates of S. musiva. Levels of susceptibility were P. balsamifera > F1 hybrid > P. deltoides. A further 53 genotypes were grown in a common garden to assess the effect of genotype on variation in leaf phenology. Leaf phenology was more variable within the category of hybrid genotypes than within categories of either parental species. Leaf phenology was also more variable for the category of trees originating in the hybrid (P. balsamifera - P. deltoides [hybrid and parental genotypes combined]) zone than in adjacent pure zones of the parental species. The results from the inoculation experiment support the hybrid intermediacy hypothesis. The results from the common garden experiment support the 'phenological sink' hypothesis. These findings have greatly increased our understanding of the epidemiology and ecology of fungal pathogens in plant

  10. Testing the 'hybrid susceptibility' and 'phenological sink' hypotheses using the P. balsamifera - P. deltoides hybrid zone and septoria leaf spot [Septoria musiva].

    Directory of Open Access Journals (Sweden)

    Jared M LeBoldus

    Full Text Available Hybrid genotypes that arise between plant species frequently have increased susceptibility to arthropod pests and fungal pathogens. This pattern has been attributed to the breakdown of plant defenses ('Hybrid susceptibility' hypothesis and (or to extended periods of susceptibility attributed to plant phenologies in zones of species overlap and (or hybridization ('phenological sink' hypothesis. We examined these hypotheses by assessing the susceptibility of parental and hybrid Populus host genotypes to a leaf spot disease caused by the fungal pathogen Septoria musiva. For this purpose, 214 genotypes were obtained from morphologically pure zones of P. balsamifera and P. deltoides, and from an intervening zone of overlap and hybridization on the drainage of the Red Deer River, Alberta, Canada. Genotypes were identified as P. balsamifera, P. deltoides, or hybrid using a suite of 27 species-specific SNP markers. Initially the genetic structure of the hybrid zone was characterized with 27.7% of trees classified as admixed individuals. To test the hybrid susceptibility hypothesis, a subset of 52 genotypes was inoculated with four isolates of S. musiva. Levels of susceptibility were P. balsamifera > F1 hybrid > P. deltoides. A further 53 genotypes were grown in a common garden to assess the effect of genotype on variation in leaf phenology. Leaf phenology was more variable within the category of hybrid genotypes than within categories of either parental species. Leaf phenology was also more variable for the category of trees originating in the hybrid (P. balsamifera - P. deltoides [hybrid and parental genotypes combined] zone than in adjacent pure zones of the parental species. The results from the inoculation experiment support the hybrid intermediacy hypothesis. The results from the common garden experiment support the 'phenological sink' hypothesis. These findings have greatly increased our understanding of the epidemiology and ecology of fungal

  11. High-resolution mapping reveals linkage between genes in common bean cultivar Ouro Negro conferring resistance to the rust, anthracnose, and angular leaf spot diseases.

    Science.gov (United States)

    Valentini, Giseli; Gonçalves-Vidigal, Maria Celeste; Hurtado-Gonzales, Oscar P; de Lima Castro, Sandra Aparecida; Cregan, Perry B; Song, Qijian; Pastor-Corrales, Marcial A

    2017-08-01

    Co-segregation analysis and high-throughput genotyping using SNP, SSR, and KASP markers demonstrated genetic linkage between Ur-14 and Co-3 4 /Phg-3 loci conferring resistance to the rust, anthracnose and angular leaf spot diseases of common bean. Rust, anthracnose, and angular leaf spot are major diseases of common bean in the Americas and Africa. The cultivar Ouro Negro has the Ur-14 gene that confers broad spectrum resistance to rust and the gene cluster Co-3 4 /Phg-3 containing two tightly linked genes conferring resistance to anthracnose and angular leaf spot, respectively. We used co-segregation analysis and high-throughput genotyping of 179 F 2:3 families from the Rudá (susceptible) × Ouro Negro (resistant) cross-phenotyped separately with races of the rust and anthracnose pathogens. The results confirmed that Ur-14 and Co-3 4 /Phg-3 cluster in Ouro Negro conferred resistance to rust and anthracnose, respectively, and that Ur-14 and the Co-3 4 /Phg-3 cluster were closely linked. Genotyping the F 2:3 families, first with 5398 SNPs on the Illumina BeadChip BARCBEAN6K_3 and with 15 SSR, and eight KASP markers, specifically designed for the candidate region containing Ur-14 and Co-3 4 /Phg-3, permitted the creation of a high-resolution genetic linkage map which revealed that Ur-14 was positioned at 2.2 cM from Co-3 4 /Phg-3 on the short arm of chromosome Pv04 of the common bean genome. Five flanking SSR markers were tightly linked at 0.1 and 0.2 cM from Ur-14, and two flanking KASP markers were tightly linked at 0.1 and 0.3 cM from Co-3 4 /Phg-3. Many other SSR, SNP, and KASP markers were also linked to these genes. These markers will be useful for the development of common bean cultivars combining the important Ur-14 and Co-3 4 /Phg-3 genes conferring resistance to three of the most destructive diseases of common bean.

  12. Expression of the Bs2 pepper gene confers resistance to bacterial spot disease in tomato.

    Science.gov (United States)

    Tai, T H; Dahlbeck, D; Clark, E T; Gajiwala, P; Pasion, R; Whalen, M C; Stall, R E; Staskawicz, B J

    1999-11-23

    The Bs2 resistance gene of pepper specifically recognizes and confers resistance to strains of Xanthomonas campestris pv. vesicatoria that contain the corresponding bacterial avirulence gene, avrBs2. The involvement of avrBs2 in pathogen fitness and its prevalence in many X. campestris pathovars suggests that the Bs2 gene may be durable in the field and provide resistance when introduced into other plant species. Employing a positional cloning strategy, the Bs2 locus was isolated and the gene was identified by coexpression with avrBs2 in an Agrobacterium-mediated transient assay. A single candidate gene, predicted to encode motifs characteristic of the nucleotide binding site-leucine-rich repeat class of resistance genes, was identified. This gene specifically controlled the hypersensitive response when transiently expressed in susceptible pepper and tomato lines and in a nonhost species, Nicotiana benthamiana, and was designated as Bs2. Functional expression of Bs2 in stable transgenic tomatoes supports its use as a source of resistance in other Solanaceous plant species.

  13. Production of Gentisyl Alcohol from Phoma herbarum Endophytic in Curcuma longa L. and Its Antagonistic Activity Towards Leaf Spot Pathogen Colletotrichum gloeosporioides.

    Science.gov (United States)

    Gupta, Suruchi; Kaul, Sanjana; Singh, Baljinder; Vishwakarma, Ram A; Dhar, Manoj K

    2016-11-01

    Endophytes from medicinal plants represent a potential source of bioactive compounds. During the present investigation, fungal endophytes were isolated from turmeric (Curcuma longa), an important medicinal plant. A total of 207 endophytic fungal isolates were obtained from the rhizome of C. longa L. They were grouped into seven genera based on morphological and molecular data. The fungal endophytes of C. longa were evaluated for antifungal activity against Colletotrichum gloeosporioides, the causal organism of leaf spot of turmeric. The disease is a major cause for economic loss in turmeric cultivation. Endophytic Phoma herbarum showed significant activity against C. gloeosporioides and was therefore selected for further studies. A compound gentisyl alcohol was isolated from P. herbarum which showed effective antagonism against C. gloeosporioides. The organism could therefore be used as a biocontrol agent against C. gloeosporioides.

  14. Generation of an infectious clone of a new Korean isolate of apple chlorotic leaf spot virus (ACLSV) driven by dual 35S and T7 promoters in a versatile binary vector

    Science.gov (United States)

    The full-length sequence of a new isolate of Apple chlorotic leaf spot virus (ACLSV) from Korea was divergent, but most closely related to the Japanese isolate A4, at 84% nucleotide identity. The full-length cDNA of the Korean isolate of ACLSV was cloned into a binary vector downstream of the bacter...

  15. First report of pecan bacterial leaf scorch caused by Xylella fastidiosa in pecan (Carya illinoinensis) in Arizona, New Mexico, California, and Texas

    Science.gov (United States)

    Pecan bacterial leaf scorch (PBLS) is a chronic disease that can cause major yield losses in pecan orchards. In the 2015-16 growing seasons, symptoms consistent with PBLS were observed in commercial pecan cultivars in AZ, NM, CA and TX. Symptoms included tan to light brown necrotic lesions, which ...

  16. The mechanics of bacterial cluster formation on plant leaf surfaces as revealed by bioreporter technology

    NARCIS (Netherlands)

    Tecon, R.; Leveau, J.H.J.

    2012-01-01

    Bacteria that colonize the leaves of terrestrial plants often occur in clusters whose size varies from a few to thousands of cells. For the formation of such bacterial clusters, two non-mutually exclusive but very different mechanisms may be proposed: aggregation of multiple cells or clonal

  17. The use of dried cerebrospinal fluid filter paper spots as a substrate for PCR diagnosis of the aetiology of bacterial meningitis in the Lao PDR

    Science.gov (United States)

    Elliott, I; Dittrich, S; Paris, D; Sengduanphachanh, A; Phoumin, P; Newton, P N

    2013-01-01

    We investigated whether dried cerebrospinal fluid (CSF) conserved on filter paper can be used as a substrate for accurate PCR diagnosis of important causes of bacterial meningitis in the Lao PDR. Using mock CSF, we investigated and optimized filter paper varieties, paper punch sizes, elution volumes and quantities of DNA template to achieve sensitive and reliable detection of bacterial DNA from filter paper specimens. FTA Elute Micro Card™ (Whatman, Maidstone, UK) was the most sensitive, consistent and practical variety of filter paper. Following optimization, the lower limit of detection for Streptococcus pneumoniae from dried mock CSF spots was 14 genomic equivalents (GE)/μL (interquartile range 5.5 GE/μL) or 230 (IQR 65) colony forming units/mL. A prospective clinical evaluation for S. pneumoniae, S. suis and Neisseria meningitidis was performed. Culture and PCR performed on fresh liquid CSF from patients admitted with a clinical diagnosis of meningitis (n = 73) were compared with results derived from dried CSF spots. Four of five fresh PCR-positive CSF samples also tested PCR positive from dried CSF spots, with one patient under the limit of detection. In a retrospective study of S. pneumoniae samples (n = 20), the median (IQR; range) CSF S. pneumoniae bacterial load was 1.1 × 104 GE/μL (1.2 × 105; 1 to 6.1 × 106 DNA GE/μL). Utilizing the optimized methodology, we estimate an extrapolated sensitivity of 90%, based on the range of CSF genome counts found in Laos. Dried CSF filter paper spots could potentially help us to better understand the epidemiology of bacterial meningitis in resource-poor settings and guide empirical treatments and vaccination policies. PMID:23738720

  18. Mulberry leaf extract mediated synthesis of gold nanoparticles and its anti-bacterial activity against human pathogens

    International Nuclear Information System (INIS)

    Adavallan, K; Krishnakumar, N

    2014-01-01

    Gold nanoparticles (Au-NPs) were synthesized at room temperature using Morus alba (mulberry) leaf extract as reducing and stabilizing agent. The development of plant mediated synthesis of nanoparticles is gaining importance due to its simplicity, low cost, non-toxicity, eco-friendliness, long term stability and reproducible aqueous synthesis method to obtain a self-assembly of nearly monodispersed Au-NPs. The formation and morphology of biosynthesized nanoparticles are investigated with the help of UV-Vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) techniques. Au-NPs formation was screened by UV-Vis spectroscopy through color conversion due to surface plasmon resonance band at 538 nm for Au-NPs. DLS studies revealed that the average size of Au-NPs was 50 nm. TEM studies showed the particles to be nearly spherical with few irregular shapes and particle size ranges 15−53 nm. The AFM image clearly shows the surface morphology of the well-dispersed Au-NPs with less than 50 nm. The high crystallinity of nanoparticles is evident from bright circular spots in the selected area electron diffraction (SAED) pattern. X-ray diffraction pattern showed high purity and face-centered cubic structure of Au-NPs. The FT-IR results indicate the presence of different functional groups present in the biomolecule capping the nanoparticles. Further, biosynthesized Au-NPs show strong zone of inhibition against Vibrio cholera (gram-negative) and Staphylococcus aureus (gram-positive) whereas, chemically synthesized Au-NPs and mulberry leaf extract exhibit a fair zone of inhibition. (papers)

  19. Mulberry leaf extract mediated synthesis of gold nanoparticles and its anti-bacterial activity against human pathogens

    Science.gov (United States)

    Adavallan, K.; Krishnakumar, N.

    2014-06-01

    Gold nanoparticles (Au-NPs) were synthesized at room temperature using Morus alba (mulberry) leaf extract as reducing and stabilizing agent. The development of plant mediated synthesis of nanoparticles is gaining importance due to its simplicity, low cost, non-toxicity, eco-friendliness, long term stability and reproducible aqueous synthesis method to obtain a self-assembly of nearly monodispersed Au-NPs. The formation and morphology of biosynthesized nanoparticles are investigated with the help of UV-Vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) techniques. Au-NPs formation was screened by UV-Vis spectroscopy through color conversion due to surface plasmon resonance band at 538 nm for Au-NPs. DLS studies revealed that the average size of Au-NPs was 50 nm. TEM studies showed the particles to be nearly spherical with few irregular shapes and particle size ranges 15-53 nm. The AFM image clearly shows the surface morphology of the well-dispersed Au-NPs with less than 50 nm. The high crystallinity of nanoparticles is evident from bright circular spots in the selected area electron diffraction (SAED) pattern. X-ray diffraction pattern showed high purity and face-centered cubic structure of Au-NPs. The FT-IR results indicate the presence of different functional groups present in the biomolecule capping the nanoparticles. Further, biosynthesized Au-NPs show strong zone of inhibition against Vibrio cholera (gram-negative) and Staphylococcus aureus (gram-positive) whereas, chemically synthesized Au-NPs and mulberry leaf extract exhibit a fair zone of inhibition.

  20. Escala diagramática para avaliação da severidade da cercosporiose em caupi Diagrammatic scale for assessment of Cercospora leaf spot severity in cowpea

    Directory of Open Access Journals (Sweden)

    Igor Corrêa Lima Albert

    2008-10-01

    Full Text Available A cercosporiose, causada por Cercospora cannescens e Pseudocercospora cruenta, é uma importante doença do caupi (Vigna unguiculata no Brasil. Devido à inexistência de métodos padronizados para quantificação dessa doença, foi desenvolvida uma escala diagramática com níveis de 1, 2, 4, 8, 16, 32, 64 e 82% de área foliar lesionada. A escala diagramática foi validada por 10 avaliadores, usando 50 folíolos de caupi com diferentes níveis de severidade, mensurados previamente com o programa Assess®. A acurácia, a precisão e a reprodutibilidade das estimativas de cada avaliador foi determinada por regressão linear simples entre a severidade real e a estimada, com e sem o auxílio da escala. Com a escala, os avaliadores obtiveram melhores níveis de acurácia e precisão das estimativas, com os erros absolutos concentrando-se na faixa de 10%. Os avaliadores apresentaram elevada repetibilidade (94% e reprodutibilidade (90% em 82,3% dos casos das estimativas com a utilização da escala. Portanto, a escala diagramática proposta é adequada para avaliação da severidade da cercosporiose do caupi.Cercospora leaf spot caused by Cercospora canescens and Pseudocercospora cruenta is an important disease of cowpea (Vigna unguiculata in Brazil. Due to the inexistence of standard methods for the assessment of this disease, a diagrammatic scale was developed with 1, 2, 4, 8, 16, 32, 64 and 82% of diseased leaf area. The diagrammatic scale was validated by 10 raters using 50 cowpea leaflets with different levels of severity previously measured by the software Assess®. The accuracy, precision and reproducibility of the estimative of each rater were determined by simple linear regression between actual and estimated severity, with and without the use of the scale. With the scale raters obtained better levels of accuracy and precision, with absolute errors concentrating around 10%. Raters showed high repeatability (94% and reproducibility ( 90% in

  1. In vitro antibacterial effect of tobacco leaf exudates against two bacterial plant pathogens

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    Yanelis Karina Capdesuñer

    2015-01-01

    Full Text Available Natural products are an alternative to control microorganisms that cause diseases in crops. This work aimed to evaluate different solvents for obtaining crude extracts from tobacco leaf exudates and to determine in vitro effect of these extracts against two phytopathogenic bacteria: Xanthomonas campestris(Xc and Pectobacterium carotovorum(Pc. Crude extracts from ten tobacco lines using solvents with polarities between 3.1 and 6.2 (dichloromethane, n-butanol, ethyl acetate, methanol and ethanol 90% were obtained. Ethanol 90% was selected as the best solvent for obtaining extracts from tobacco leaf exudates and as a substitute of dichloromethane due to the best yield. The chemical composition diversity of the ethanolic extracts was revealed by thin-layer chromatography. The antibacterial activity was evaluated by agar disk diffusion method recording the inhibition zones. Growth inhibition was observed for all extracts against Xc, and the better activity corresponded to the lines Nic 1061"TI 1738" and Nic 1016 "Incekara" until a minimal amount of 5 µg/ disc, with higher yield in case of the line Nic1061 . Only the extract of the line Nic 1015 was able to inhibit the growth of Pc until a minimal inhibitory concentration of 5 µg/disc. These results suggest a potential use of crude extracts from lines Nic 1061 and Nic 1015 "TI 1341" as an effective agent for the crop protection against Xc and Pc respectively.

  2. An Endophytic Bacterial Strain Isolated from Eucommia ulmoides Inhibits Southern Corn Leaf Blight

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    Ting Ding

    2017-05-01

    Full Text Available Bacillus subtilis DZSY21 isolated from the leaves of Eucommia ulmoides oliv. was labeled by antibiotic marker and found to effectively colonize the leaves of maize plant. Agar diffusion assays and biocontrol effect experiments showed that strain DZSY21 and its lipopeptides had antagonistic activity against Bipolaris maydis, as well as high biocontrol effects on southern corn leaf blight caused by B. maydis. Using MALDI-TOF-MS analysis, we detected the presence of antimicrobial surfactin A, surfactin B, and fengycin in the strain DZSY21. Signaling pathways mediated by DZSY21 were analyzed by testing the expression of key plant genes involved in regulation of salicylic acid (SA or JA/ET pathways, the defense-related genes PR1 and LOX were concurrently expressed in the leaves of DZSY21-treated plants; this corresponded to slight increase in the expression level of PDF1.2 and decreases in ERF gene transcription levels. The results indicated an induced systemic response that is dependent on the SA and jasmonic acid (JA pathways. Thus, we hypothesized that the strain DZSY21 inhibits B. maydis by producing antifungal lipopeptides and activating an induced systemic response through SA- and JA-dependent signaling pathways. This work describes a mechanism behind reduced disease severity in plants inoculated with the endophytic bacteria DZSY21.

  3. Combining powers of linkage and association mapping for precise dissection of QTL controlling resistance to gray leaf spot disease in maize (Zea mays L.).

    Science.gov (United States)

    Mammadov, Jafar; Sun, Xiaochun; Gao, Yanxin; Ochsenfeld, Cherie; Bakker, Erica; Ren, Ruihua; Flora, Jonathan; Wang, Xiujuan; Kumpatla, Siva; Meyer, David; Thompson, Steve

    2015-11-10

    Gray Leaf Spot (GLS causal agents Cercospora zeae-maydis and Cercospora zeina) is one of the most important foliar diseases of maize in all areas where the crop is being cultivated. Although in the USA the situation with GLS severity is not as critical as in sub-Saharan Africa or Brazil, the evidence of climate change, increasing corn monoculture as well as the narrow genetic base of North American resistant germplasm can turn the disease into a serious threat to US corn production. The development of GLS resistant cultivars is one way to control the disease. In this study we combined the high QTL detection power of genetic linkage mapping with the high resolution power of genome-wide association study (GWAS) to precisely dissect QTL controlling GLS resistance and identify closely linked molecular markers for robust marker-assisted selection and trait introgression. Using genetic linkage analysis with a small bi-parental mapping population, we identified four GLS resistance QTL on chromosomes 1, 6, 7, and 8, which were validated by GWAS. GWAS enabled us to dramatically increase the resolution within the confidence intervals of the above-mentioned QTL. Particularly, GWAS revealed that QTLGLSchr8, detected by genetic linkage mapping as a locus with major effect, was likely represented by two QTL with smaller effects. Conducted in parallel, GWAS of days-to-silking demonstrated the co-localization of flowering time QTL with GLS resistance QTL on chromosome 7 indicating that either QTLGLSchr7 is a flowering time QTL or it is a GLS resistance QTL that co-segregates with the latter. As a result, this genetic linkage - GWAS hybrid mapping system enabled us to identify one novel GLS resistance QTL (QTLGLSchr8a) and confirm with more refined positions four more previously mapped QTL (QTLGLSchr1, QTLGLSchr6, QTLGLSchr7, and QTLGLSchr8b). Through the novel Single Donor vs. Elite Panel method we were able to identify within QTL confidence intervals SNP markers that would be

  4. Encountering epidemic effects of leaf spot disease (Alternaria brassicae) on Aloe vera by fungal biocontrol agents in agrifields-An ecofriendly approach.

    Science.gov (United States)

    Ghosh, Swapan Kumar; Banerjee, Subhankar; Pal, Sujoy; Chakraborty, Niloy

    2018-01-01

    Aloe vera (L.) Burm.f. is a highly important and extensively cultivated medicinal plant and that is also extensively used in the cosmetic industry. It has been frequently reported to suffer from Alternaria leaf spot disease in various parts of the world. Various fungicides used to combat this disease, have deleterious effects on the environment and on pharmacologically important constituents of Aloe vera. To avoid the harmful effects of fungicides an ecofriendly approach has been adopted here. A weekly survey was conducted during 2013-2015 in and around North 24 Parganas (West Bengal) to obtain the percentage of disease index (PDI). For biological control of the disease, screening of the antagonistic efficacy of biocontrol agents was carried out through the in vitro dual-culture-plate method and scanning electron microscopy (SEM) was used to study the mechanism. The in vitro effects of fungicides on the radial growth of the pathogen were evaluated through the poison food method and were compared with potent antagonistic fungi. Field application of potent antagonistic fungi was conducted through the dip-and-spray method. The results showed that, the PDI peaked during the hot and humid conditions of May to September (76.57%-98.57%) but decreased during the winter, December-January (35.71-46.66%). Trichoderma asperellum exerted the greatest inhibition of the radial growth of A. brassicae acting through non volatile (70.39%) and volatile metabolites (72.17%). A SEM study confirmed the hyperparasitic nature of T. asperellum through hyphal coiling-T. asperellum was similar to 2% blitox-50 (73.92%) and better than 2% bavistin (59.77%) (in vitro). In agricultural field trials (2013-15), Trichoderma application restricted the disease to the smallest area (PDI 24.00-29.33%) in comparison to untreated plots (73.33%). In conclusion, saplings treated with the dip method (108 spores / mL) and sprayed 4 times with a spore suspension of biocontrol agents such as T. asperellum, T

  5. Faba Bean Can Adapt to Chocolate Spot Disease by Pretreatment with Shikimic and Salicylic Acids through Osmotic Adjustment, Solutes Allocation and Leaf Turgidity

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    Heshmat S. Aldesuquy

    2014-03-01

    Full Text Available This study investigated the effect of shikimic and salicylic acids at the concentrations of 0.4 and 0.7 mM, respectively, or their combination as phenolic compounds and Ridomil MZ at the concentration of 250 g/100 L as a fungicide on osmotic pressure (OP, solutes allocation, organic acids, inorganic ions and relative water content were quantified in Vicia faba leaves infected by Botrytis fabae. Pathogen induced noticeable decrease in osmotic pressure, total soluble sugar (TSS and inorganic osmolytes (i.e. Na+, K+, Ca2+, Mg2+ and Cl- while caused obvious increase in proline, total soluble nitrogen (TSN and organic acids (i.e. Keto and citric acids in water extract of the leaf of faba bean plants. Furthermore, pathogen caused marked decrease in relative water content (RWC of infected leaves and as a consequence the saturation water deficit (SWD was increased. Exogenous application of shikimic acid, salicylic acid or their combination could counteract the adverse effects of B. fabae on osmotic adjustment by inducing additional increase in proline, total soluble sugars, total soluble nitrogen and organic acids which in turn increase the osmotic pressure as well as relative water content in leaves of infected plants. Recovery of osmotic adjustment as well as leaf turgidity of infected host by using these chemical inducers may encourage the using of them as protective control means. The results of the present study showed also that the application of chemical inducers such as shikimic and salicylic acids or their interaction increased the resistance of Vicia faba against the chocolate spot disease.

  6. NMR-Based Metabolic Profiling of Field-Grown Leaves from Sugar Beet Plants Harbouring Different Levels of Resistance to Cercospora Leaf Spot Disease

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    Yasuyo Sekiyama

    2017-01-01

    Full Text Available Cercospora leaf spot (CLS is one of the most serious leaf diseases for sugar beet (Beta vulgaris L. worldwide. The breeding of sugar beet cultivars with both high CLS resistance and high yield is a major challenge for breeders. In this study, we report the nuclear magnetic resonance (NMR-based metabolic profiling of field-grown leaves for a subset of sugar beet genotypes harbouring different levels of CLS resistance. Leaves were collected from 12 sugar beet genotypes at four time points: seedling, early growth, root enlargement, and disease development stages. 1H-NMR spectra of foliar metabolites soluble in a deuterium-oxide (D2O-based buffer were acquired and subjected to multivariate analyses. A principal component analysis (PCA of the NMR data from the sugar beet leaves shows clear differences among the growth stages. At the later time points, the sugar and glycine betaine contents were increased, whereas the choline content was decreased. The relationship between the foliar metabolite profiles and resistance level to CLS was examined by combining partial least squares projection to latent structure (PLS or orthogonal PLS (OPLS analysis and univariate analyses. It was difficult to build a robust model for predicting precisely the disease severity indices (DSIs of each genotype; however, GABA and Gln differentiated susceptible genotypes (genotypes with weak resistance from resistant genotypes (genotypes with resistance greater than a moderate level before inoculation tests. The results suggested that breeders might exclude susceptible genotypes from breeding programs based on foliar metabolites profiled without inoculation tests, which require an enormous amount of time and effort.

  7. Contribution of the drought tolerance-related Stress-responsive NAC1 transcription factor to resistance of barley to Ramularia leaf spot

    Science.gov (United States)

    MCGRANN, GRAHAM R D; STEED, ANDREW; BURT, CHRISTOPHER; GODDARD, RACHEL; LACHAUX, CLEA; BANSAL, ANURADHA; CORBITT, MARGARET; GORNIAK, KALINA; NICHOLSON, PAUL; BROWN, JAMES K M

    2015-01-01

    NAC proteins are plant transcription factors that are involved in tolerance to abiotic and biotic stresses, as well as in many developmental processes. Stress-responsive NAC1 (SNAC1) transcription factor is involved in drought tolerance in barley and rice, but has not been shown previously to have a role in disease resistance. Transgenic over-expression of HvSNAC1 in barley cv. Golden Promise reduced the severity of Ramularia leaf spot (RLS), caused by the fungus Ramularia collo-cygni, but had no effect on disease symptoms caused by Fusarium culmorum, Oculimacula yallundae (eyespot), Blumeria graminis f. sp. hordei (powdery mildew) or Magnaporthe oryzae (blast). The HvSNAC1 transcript was weakly induced in the RLS-susceptible cv. Golden Promise during the latter stages of R. collo-cygni symptom development when infected leaves were senescing. Potential mechanisms controlling HvSNAC1-mediated resistance to RLS were investigated. Gene expression analysis revealed no difference in the constitutive levels of antioxidant transcripts in either of the over-expression lines compared with cv. Golden Promise, nor was any difference in stomatal conductance or sensitivity to reactive oxygen species-induced cell death observed. Over-expression of HvSNAC1 delayed dark-induced leaf senescence. It is proposed that mechanisms controlled by HvSNAC1 that are involved in tolerance to abiotic stress and that inhibit senescence also confer resistance to R. collo-cygni and suppress RLS symptoms. This provides further evidence for an association between abiotic stress and senescence in barley and the development of RLS. PMID:25040333

  8. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  9. Resistance to gray leaf spot of maize: genetic architecture and mechanisms elucidated through nested association mapping and near-isogenic line analysis.

    Science.gov (United States)

    Benson, Jacqueline M; Poland, Jesse A; Benson, Brent M; Stromberg, Erik L; Nelson, Rebecca J

    2015-03-01

    Gray leaf spot (GLS), caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR) loci. Nested association mapping (NAM) was used to identify 16 quantitative trait loci (QTL) for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs) were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis) and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO) gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will facilitate the

  10. Resistance to gray leaf spot of maize: genetic architecture and mechanisms elucidated through nested association mapping and near-isogenic line analysis.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Benson

    2015-03-01

    Full Text Available Gray leaf spot (GLS, caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR loci. Nested association mapping (NAM was used to identify 16 quantitative trait loci (QTL for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will

  11. A new gene, developed through mutagenesis with thermal neutrons, for resistance of rice to bacterial leaf blight

    International Nuclear Information System (INIS)

    Nakai, H.; Shimozawa, H.; Saito, M.

    1992-01-01

    Dry seed lots of a rice variety, Harebare, susceptible to bacterial leaf blight (BLB), were treated with thermal neutrons with and without pre-treatment of the seeds by boron-enrichment, gamma-rays and nitroso-methyl-urea (NMU). The selections were made on M 2 -M 3 materials by inoculation of Japanese BLB race III, with the result that several BLB resistant mutants to race III and the other differential races could be obtained. Mutagenic efficiency of thermal neutrons to the seeds without boron-enrichment for induction of BLB resistant mutants was found to be significantly higher than that of the other mutagens. Four mutant lines of all the selected ones were analyzed for genes for BLB resistance through cross tests between the mutants and the original variety. Harebare, indicating that the resistance in the mutants was conditioned by single recessive gene(s). The mutant designated 86M95 was especially noted for its gene conferring complete (or durable) resistance to multiple BLB races. The 86M95 mutant or the gene may be of practical value for breeding of rice for BLB resistance. (author)

  12. In Vitro Rumen Fermentation and Anti Mastitis Bacterial Activity of Diet Containing Betel Leaf Meal (Piper betle L.

    Directory of Open Access Journals (Sweden)

    A. A. Yamin

    2013-08-01

    Full Text Available The aims of this experiment was to study the inhibition effect of betel leaf meal (BLM addition into concentrate diet on mastitis causing bacteria and on rumen fermentation condition. The study consisted of five dietary treatments of BLM level in concentrate feed, i.e., 0%, 2%, 4%, 6%, and 8% and four replicates of each treatment. The treatment diets together with napier grass in ratio of 40 : 60 were fermented using rumen liquor. All treatments were examined their antibacterial activity before and after fermentation. After four hours fermentation, supernatant of each samples were analyzed for VFA, NH3, number of bacteria and protozoa. Dry matter (DM and organic matter (OM digestibility were analyzed after 48 h fermentation. The results showed that before fermentation, 8% BLM addition caused the bigest (P<0.05 inhibition diameter of Staphylococcus spp. growth compared to other lower levels. However after fermentation there were no significant differences among the addition levels of BLM. Two per cent of BLM addition produced higher VFA (P<0.05 than the other addition levels. Ammonia concentration, dry matter (DM and organic matter (OM digestibility were not different among the treatments. Addition of BLM significantly (P<0.01 decreased protozoa number, but did not affect bacterial count. It is concluded that the addition of 2% BLM in concentrate feed can be used effectively to inhibit the growth of mastitis causing bacteria (Staphylococcus spp. and does not disturb rumen fermentation condition.

  13. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

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    Hue Thi Nguyen

    2018-01-01

    Full Text Available Bacterial leaf blight of rice (BLB, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F3 5.1.5.1, BC3F3 5.1.5.12, BC3F3 8.5.6.44, BC3F3 9.5.4.1 and BC3F3 9.5.4.23 were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  14. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

    Institute of Scientific and Technical Information of China (English)

    Hue Thi NGUYEN; Trung Nguyen DINH; Nakano TOSHITSUGU; Liet Van VU; Quang Hong VU; Tan Van MAI; Thu Thi NGUYEN; Lam Duc VU; Tung Thanh NGUYEN; Long Viet NGUYEN; Hien Thu Thi VU; Hue Thi NONG

    2018-01-01

    Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F35.1.5.1, BC3F35.1.5.12, BC3F38.5.6.44, BC3F3 9.5.4.1 and BC3F39.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  15. Construction of Double Right-Border Binary Vector Carrying Non-Host Gene Rxol Resistant to Bacterial Leaf Streak of Rice

    Institute of Scientific and Technical Information of China (English)

    Xu Mei-rong; XIA Zhi-hui; ZHAI Wen-xue; XU Jian-long; ZHOU Yong-li; LI Zhi-kang

    2008-01-01

    Rxol cloned from maize is a non-host gene resistant to bacterial leaf streak of rice. pCAMBIA1305-1 with Rxol was digested with Sca Ⅰ and NgoM Ⅳ and the double right-border binary vector pMNDRBBin6 was digested with Hpa Ⅰ and Xma Ⅰ.pMNDRBBin6 carrying the gene Rxol was acquired by ligation of blunt-end and cohesive end. The results of PCR, restriction enzyme analysis and sequencing indicated that the Rxol gene had been cloned into pMNDRBBin6. This double right-border binary vector,named as pMNDRBBin6-Rxol, will play a role in breeding marker-free plants resistant to bacterial leaf streak of rice by genetic transformation.

  16. Potential applications for Annona squamosa leaf extract in the treatment and prevention of foodborne bacterial disease.

    Science.gov (United States)

    Dholvitayakhun, Achara; Trachoo, Nathanon; Sakee, Uthai; Cushnie, T P Tim

    2013-03-01

    Foodborne disease is a major public health problem. The present study examined Annona squamosa leaves, which are traditionally used to treat diarrhea and other infections, for their potential to be used in modern food safety or medicine. Active constituents were partially purified by ethanol extraction and column chromatography. MICs of the extract were 62.5 to 125 microg/mL against Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus, and 250 microg/mL against Campylobacter jejuni. In time-kill assays, 500 microg/mL of the extract reduced colony forming unit numbers of C. jejuni almost 10 000-fold within 12 hours. Similar decreases were seen against B. cereus, but over a longer time-frame. LC-MS analysis indicated the presence of reticuline and oxophoebine. Assessment of stability by MIC assay showed activity was heat-labile, with loss of activity greatest following high temperature treatments. Activity was relatively stable at refrigeration temperature. These results indicate A. squamosa has broad-spectrum but heat-labile activity against foodborne bacterial pathogens, and bactericidal activity against B. cereus and C. jejuni. This bactericidal activity is not sufficiently rapid for A. squamosa to be used as a food sanitizer, but the extract could potentially be developed as an additive for refrigerated foods, or a modern treatment for foodborne illness.

  17. Are leaf glandular trichomes of oregano hospitable habitats for bacterial growth?

    Science.gov (United States)

    Karamanoli, K; Thalassinos, G; Karpouzas, D; Bosabalidis, A M; Vokou, D; Constantinidou, H-I

    2012-05-01

    Phyllospheric bacteria were isolated from microsites around essential-oil-containing glands of two oregano (Origanum vulgare subsp. hirtum) lines. These bacteria, 20 isolates in total, were subjected to bioassays to examine their growth potential in the presence of essential oils at different concentrations. Although there were qualitative and quantitative differences in the essential oil composition between the two oregano lines, no differences were recorded in their antibacterial activity. In disk diffusion bioassays, four of the isolated strains could grow almost unrestrained in the presence of oregano oil, another five proved very sensitive, and the remaining 11 showed intermediate sensitivity. The strain least inhibited by oregano essential oil was further identified by complete16s rRNA gene sequencing as Pseudomonas putida. It was capable of forming biofilms even in the presence of oregano oil at high concentrations. Resistance of P. putida to oregano oil was further elaborated by microwell dilution bioassays, and its topology on oregano leaves was studied by electron microscopy. When inoculated on intact oregano plants, P. putida was able not only to colonize sites adjacent to essential oil-containing glands, but even to grow intracellularly. This is the first time that such prolific bacterial growth inside the glands has been visually observed. Results of this study further revealed that several bacteria can be established on oregano leaves, suggesting that these bacteria have attributes that allow them to tolerate or benefit from oregano secondary metabolites.

  18. Identification of SSR and RAPD markers linked to a resistance allele for angular leaf spot in the common bean (Phaseolus vulgaris line ESAL 550

    Directory of Open Access Journals (Sweden)

    Gilvan Ferreira da Silva

    2003-12-01

    Full Text Available The objective of this study was to identify RAPD and SSR markers associated with a resistant allele for angular leaf spot (Phaeoisariopsis griseola from the line 'ESAL 550', derived from the Andean 'Jalo EEP 558' cultivar, to assist selection of resistant genotypes. The resistant line 'ESAL 550' and the susceptible cultivar 'Carioca MG' were crossed to generate F1 and F2 populations. One hundred and twenty F2:3 families were evaluated. The DNA of the 12 most resistant families was bulked and the same was done with the DNA of the 10 most susceptible, generating two contrasting bulks. One RAPD and one SSR marker was found to be linked in coupling phase to the resistant allele. The SSR marker was amplified by the primer PV-atct001(282C, and its distance from the resistant allele was 7.6 cM. This is the most useful marker for indirect selection of resistant plants in segregating populations. The RAPD marker was amplified by the primer OPP07(857C linked in coupling phase to the resistant allele, and distant 24.4 cM. Therefore, this RAPD marker is not so useful in assisting selection because it is too far from the resistant allele.

  19. The Cucumber leaf spot virus p25 auxiliary replicase protein binds and modifies the endoplasmic reticulum via N-terminal transmembrane domains

    Energy Technology Data Exchange (ETDEWEB)

    Ghoshal, Kankana [University of British Columbia, Faculty of Land and Food Systems, Vancouver, British Columbia, Canada V6T 1Z4 (Canada); Theilmann, Jane; Reade, Ron; Sanfacon, Helene [Agriculture and Agri-Food Canada Pacific Agri-Food Research Centre, 4200 Hwy 97, Summerland, British Columbia, Canada V0H 1Z0 (Canada); Rochon, D’Ann, E-mail: dann.rochon@agr.gc.ca [University of British Columbia, Faculty of Land and Food Systems, Vancouver, British Columbia, Canada V6T 1Z4 (Canada); Agriculture and Agri-Food Canada Pacific Agri-Food Research Centre, 4200 Hwy 97, Summerland, British Columbia, Canada V0H 1Z0 (Canada)

    2014-11-15

    Cucumber leaf spot virus (CLSV) is a member of the Aureusvirus genus, family Tombusviridae. The auxiliary replicase of Tombusvirids has been found to localize to endoplasmic reticulum (ER), peroxisomes or mitochondria; however, localization of the auxiliary replicase of aureusviruses has not been determined. We have found that the auxiliary replicase of CLSV (p25) fused to GFP colocalizes with ER and that three predicted transmembrane domains (TMDs) at the N-terminus of p25 are sufficient for targeting, although the second and third TMDs play the most prominent roles. Confocal analysis of CLSV infected 16C plants shows that the ER becomes modified including the formation of punctae at connections between ER tubules and in association with the nucleus. Ultrastructural analysis shows that the cytoplasm contains numerous vesicles which are also found between the perinuclear ER and nuclear membrane. It is proposed that these vesicles correspond to modified ER used as sites for CLSV replication. - Highlights: • The CLSV p25 auxiliary replicase targets the endoplasmic reticulum (ER). • Targeting of CLSV p25 is associated with ER restructuring. • Restructuring of the ER occurs during CLSV infection. • CLSV p25 contains 3 predicted transmembrane domains 2 of which are required for ER targeting. • Vesicles derived from the ER may be sites of CLSV replication.

  20. The Cucumber leaf spot virus p25 auxiliary replicase protein binds and modifies the endoplasmic reticulum via N-terminal transmembrane domains

    International Nuclear Information System (INIS)

    Ghoshal, Kankana; Theilmann, Jane; Reade, Ron; Sanfacon, Helene; Rochon, D’Ann

    2014-01-01

    Cucumber leaf spot virus (CLSV) is a member of the Aureusvirus genus, family Tombusviridae. The auxiliary replicase of Tombusvirids has been found to localize to endoplasmic reticulum (ER), peroxisomes or mitochondria; however, localization of the auxiliary replicase of aureusviruses has not been determined. We have found that the auxiliary replicase of CLSV (p25) fused to GFP colocalizes with ER and that three predicted transmembrane domains (TMDs) at the N-terminus of p25 are sufficient for targeting, although the second and third TMDs play the most prominent roles. Confocal analysis of CLSV infected 16C plants shows that the ER becomes modified including the formation of punctae at connections between ER tubules and in association with the nucleus. Ultrastructural analysis shows that the cytoplasm contains numerous vesicles which are also found between the perinuclear ER and nuclear membrane. It is proposed that these vesicles correspond to modified ER used as sites for CLSV replication. - Highlights: • The CLSV p25 auxiliary replicase targets the endoplasmic reticulum (ER). • Targeting of CLSV p25 is associated with ER restructuring. • Restructuring of the ER occurs during CLSV infection. • CLSV p25 contains 3 predicted transmembrane domains 2 of which are required for ER targeting. • Vesicles derived from the ER may be sites of CLSV replication

  1. Geographical distribution of myrothecium leaf spot disease of momordica charantial L. caused by myrothecium roridum tode in agro-ecological zone of punjab, Pakistan

    International Nuclear Information System (INIS)

    Din, G. M.; Farooq, S.; Khan, S. N.; Imani, J.; Naz, S.

    2017-01-01

    A series of field surveys were carried out during July-October 2012-14 for the development of disease distribution map and updating the index of Myrothecium leaf spot of Momordica charantia (Bitter gourd) in Punjab province. A total of 29 districts were surveyed belonging to 9 sub agro ecological zones of Punjab. The index was calculated on the basis of incidence, prevalence and severity of the disease. The information from stakeholders was gathered through field scouting, formal and informal discussions. Data on socioeconomics was collected by a structured questionnaire. The symptomatic plants and soil specimens were collected form diseased field and transferred to lab for onward studies on host-pathogen characterization and management. Infection development on the plant was investigated on a (0-5) visual severity rating scale. Fungus was isolated, identified on morphological and molecular characteristics as Myrothecium roridum and cultures were deposited to First Fungal Culture Bank of Pakistan (Accession No. FCBP 1155) and Leibniz-institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany (Accession No. DSM 28971). Data gathered highlighted dominance of the disease in mixed cropping zone of Punjab province. Highest disease index (31%) was recorded in mixed cropping zone and lowest (3%) in D.G khan zone. However its severity may vary due to adopted cultural and chemical practices by individual farmers. The investigations strengthen the involvement of irrigation technique, soil type and cropping history in introduction and sporadic occurrence of the disease. (author)

  2. Implication of the Bacterial Endosymbiont Rickettsia spp. in Interactions of the Whitefly Bemisia tabaci with Tomato yellow leaf curl virus

    Science.gov (United States)

    Kliot, Adi; Cilia, Michelle; Czosnek, Henryk

    2014-01-01

    ABSTRACT Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. We report here that infection with Rickettsia spp., a facultative endosymbiont of whiteflies, altered TYLCV-B. tabaci interactions. A B. tabaci strain infected with Rickettsia acquired more TYLCV from infected plants, retained the virus longer, and exhibited nearly double the transmission efficiency compared to an uninfected B. tabaci strain with the same genetic background. Temporal and spatial antagonistic relationships were discovered between Rickettsia and TYLCV within the whitefly. In different time course experiments, the levels of virus and Rickettsia within the insect were inversely correlated. Fluorescence in situ hybridization analysis of Rickettsia-infected midguts provided evidence for niche exclusion between Rickettsia and TYLCV. In particular, high levels of the bacterium in the midgut resulted in higher virus concentrations in the filter chamber, a favored site for virus translocation along the transmission pathway, whereas low levels of Rickettsia in the midgut resulted in an even distribution of the virus. Taken together, these results indicate that Rickettsia, by infecting the midgut, increases TYLCV transmission efficacy, adding further insights into the complex association between persistent plant viruses, their insect vectors, and microorganism tenants that reside within these insects. IMPORTANCE Interest in bacterial endosymbionts in arthropods and many aspects of their host biology in agricultural and human health systems has been increasing. A recent and relevant studied example is the influence of Wolbachia on dengue virus transmission by mosquitoes. In parallel with our recently studied whitefly-Rickettsia-TYLCV system, other studies have shown that dengue virus levels in the mosquito vector are inversely correlated with

  3. High-resolution mapping and characterization of qRgls2, a major quantitative trait locus involved in maize resistance to gray leaf spot.

    Science.gov (United States)

    Xu, Ling; Zhang, Yan; Shao, Siquan; Chen, Wei; Tan, Jing; Zhu, Mang; Zhong, Tao; Fan, Xingming; Xu, Mingliang

    2014-08-31

    Gray leaf spot (GLS) caused by Cercospora zeae-maydis (Czm) or Cercospora zeina (Cz) is a devastating maize disease and results in substantial yield reductions worldwide. GLS resistance is a quantitatively inherited trait. The development and cultivation of GLS-resistant maize hybrids are the most cost-effective and efficient ways to control this disease. We previously detected a major GLS resistance QTL, qRgls2, in bin 5.03-04, which spans the whole centromere of chromosome 5 encompassing a physical distance of ~110-Mb. With advanced backcross populations derived from the cross between the resistant Y32 and susceptible Q11 inbred lines, a sequential recombinant-derived progeny testing strategy was adapted to fine map qRgls2. We narrowed the region of qRgls2 from an initial ~110-Mb to an interval of ~1-Mb, flanked by the markers G346 and DD11. qRgls2 showed predominantly additive genetic effects and significantly increased the resistance percentage by 20.6 to 24.6% across multiple generations. A total of 15 genes were predicted in the mapped region according to the 5b.60 annotation of the maize B73 genome v2. Two pieces of the mapped qRgls2 region shared collinearity with two distant segments on maize chromosome 4. qRgls2, a major QTL involved in GLS resistance, was mapped to a ~1-Mb region close to the centromere of chromosome 5. There are 15 predicted genes in the mapped region. It is assumed that qRgls2 could be widely used to improve maize resistance to GLS.

  4. QTL-seq approach identified genomic regions and diagnostic markers for rust and late leaf spot resistance in groundnut (Arachis hypogaea L.).

    Science.gov (United States)

    Pandey, Manish K; Khan, Aamir W; Singh, Vikas K; Vishwakarma, Manish K; Shasidhar, Yaduru; Kumar, Vinay; Garg, Vanika; Bhat, Ramesh S; Chitikineni, Annapurna; Janila, Pasupuleti; Guo, Baozhu; Varshney, Rajeev K

    2017-08-01

    Rust and late leaf spot (LLS) are the two major foliar fungal diseases in groundnut, and their co-occurrence leads to significant yield loss in addition to the deterioration of fodder quality. To identify candidate genomic regions controlling resistance to rust and LLS, whole-genome resequencing (WGRS)-based approach referred as 'QTL-seq' was deployed. A total of 231.67 Gb raw and 192.10 Gb of clean sequence data were generated through WGRS of resistant parent and the resistant and susceptible bulks for rust and LLS. Sequence analysis of bulks for rust and LLS with reference-guided resistant parent assembly identified 3136 single-nucleotide polymorphisms (SNPs) for rust and 66 SNPs for LLS with the read depth of ≥7 in the identified genomic region on pseudomolecule A03. Detailed analysis identified 30 nonsynonymous SNPs affecting 25 candidate genes for rust resistance, while 14 intronic and three synonymous SNPs affecting nine candidate genes for LLS resistance. Subsequently, allele-specific diagnostic markers were identified for three SNPs for rust resistance and one SNP for LLS resistance. Genotyping of one RIL population (TAG 24 × GPBD 4) with these four diagnostic markers revealed higher phenotypic variation for these two diseases. These results suggest usefulness of QTL-seq approach in precise and rapid identification of candidate genomic regions and development of diagnostic markers for breeding applications. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  5. DnaK as Antibiotic Target: Hot Spot Residues Analysis for Differential Inhibition of the Bacterial Protein in Comparison with the Human HSP70.

    Directory of Open Access Journals (Sweden)

    Federica Chiappori

    Full Text Available DnaK, the bacterial homolog of human Hsp70, plays an important role in pathogens survival under stress conditions, like antibiotic therapies. This chaperone sequesters protein aggregates accumulated in bacteria during antibiotic treatment reducing the effect of the cure. Although different classes of DnaK inhibitors have been already designed, they present low specificity. DnaK is highly conserved in prokaryotes (identity 50-70%, which encourages the development of a unique inhibitor for many different bacterial strains. We used the DnaK of Acinetobacter baumannii as representative for our analysis, since it is one of the most important opportunistic human pathogens, exhibits a significant drug resistance and it has the ability to survive in hospital environments. The E.coli DnaK was also included in the analysis as reference structure due to its wide diffusion. Unfortunately, bacterial DnaK and human Hsp70 have an elevated sequence similarity. Therefore, we performed a differential analysis of DnaK and Hsp70 residues to identify hot spots in bacterial proteins that are not present in the human homolog, with the aim of characterizing the key pharmacological features necessary to design selective inhibitors for DnaK. Different conformations of DnaK and Hsp70 bound to known inhibitor-peptides for DnaK, and ineffective for Hsp70, have been analysed by molecular dynamics simulations to identify residues displaying stable and selective interactions with these peptides. Results achieved in this work show that there are some residues that can be used to build selective inhibitors for DnaK, which should be ineffective for the human Hsp70.

  6. Md-miR156ab and Md-miR395 Target WRKY Transcription Factors to Influence Apple Resistance to Leaf Spot Disease.

    Science.gov (United States)

    Zhang, Qiulei; Li, Yang; Zhang, Yi; Wu, Chuanbao; Wang, Shengnan; Hao, Li; Wang, Shengyuan; Li, Tianzhong

    2017-01-01

    MicroRNAs (miRNAs) are key regulators of gene expression that post-transcriptionally regulate transcription factors involved in plant physiological activities. Little is known about the effects of miRNAs in disease resistance in apple ( Malus × domestica ). We globally profiled miRNAs in the apple cultivar Golden Delicious (GD) infected or not with the apple leaf spot fungus Alternaria alternaria f. sp. mali (ALT1), and identified 58 miRNAs that exhibited more than a 2-fold upregulation upon ALT1 infection. We identified a pair of miRNAs that target protein-coding genes involved in the defense response against fungal pathogens; Md-miR156ab targets a novel WRKY transcription factor, MdWRKYN1, which harbors a TIR and a WRKY domain. Md-miR395 targets another transcription factor, MdWRKY26, which contains two WRKY domains. Real-time PCR analysis showed that Md-miR156ab and Md-miR395 levels increased, while MdWRKYN1 and MdWRKY26 expression decreased in ALT1-inoculated GD leaves; furthermore, the overexpression of Md-miR156ab and Md-miR395 resulted in a significant reduction in MdWRKYN1 and MdWRKY26 expression. To investigate whether these miRNAs and their targets play a crucial role in plant defense, we overexpressed MdWRKYN1 or knocked down Md-miR156ab activity, which in both cases enhanced the disease resistance of the plants by upregulating the expression of the WRKY-regulated pathogenesis-related (PR) protein-encoding genes MdPR3-1, MdPR3-2, MdPR4, MdPR5, MdPR10-1 , and MdPR10-2 . In a similar analysis, we overexpressed MdWRKY26 or suppressed Md-miR395 activity, and found that many PR protein-encoding genes were also regulated by MdWRKY26 . In GD, ALT-induced Md-miR156ab and Md-miR395 suppress MdWRKYN1 and MdWRKY26 expression, thereby decreasing the expression of some PR genes, and resulting in susceptibility to ALT1.

  7. Clarification of the Etiology of Glomerella Leaf Spot and Bitter Rot of Apple Caused by Colletotrichum spp. Based on Morphology and Genetic, Molecular, and Pathogenicity Tests.

    Science.gov (United States)

    González, Eugenia; Sutton, Turner B; Correll, James C

    2006-09-01

    ABSTRACT Morphological characteristics and vegetative compatibility groups (VCGs) of 486 isolates of Glomerella cingulata, Colletotrichum gloeosporioides, and C. acutatum collected from apple leaves with Glomerella leaf spot (GLS) symptoms and fruit with bitter rot symptoms in the United States and Brazil were studied. From this collection, 155 isolates of G. cingulata (93 from fruit, 61 from leaves, and 1 from buds), 42 isolates of C. gloeosporioides from fruit, and 14 isolates of C. acutatum (10 from fruit and 4 from leaves) were studied using mitochondrial (mt)DNA restriction fragment length polymorphism (RFLP) haplotypes. A subset of 24 isolates was studied by examining the sequence of a 200-bp intron of the glyceraldehyde 3-phosphate dehydrogenase (GDPH) nuclear gene. In addition, 98 isolates were tested for pathogenicity on leaves of cvs. Gala and Golden Delicious in the greenhouse, and 24 isolates were tested for pathogenicity on fruit of cv. Gala in growth chambers. In total, 238 and 225 isolates of G. cingulata were separated into four distinct morphological types and six VCGs, respectively. Five morphological types and six VCGs were identified among 74 and 36 isolates of C. gloeosporioides, respectively. Three morphological types and four VCGs were identified among 74 and 23 isolates of C. acutatum, respectively. Seven different mtDNA RFLP haplotypes were observed within isolates of G. cingulata, two within isolates of C. gloeosporioides, and two within isolates of C. acutatum. Phylogenetic trees, inferred based on maximum likelihood and maximum parsimony methods using the intron sequence, produced similar topologies. Each species was separated into distinct groups. All isolates tested were pathogenic on fruit, though only isolates with specific VCGs and haplotypes were pathogenic to leaves. Vegetative compatibility was a better tool than molecular characters for distinguishing isolates of G. cingulata pathogenic on both leaves and fruit from the ones

  8. Liver spots

    Science.gov (United States)

    ... skin changes - liver spots; Senile or solar lentigines; Skin spots - aging; Age spots ... Liver spots are changes in skin color that occur in older skin. The coloring may be due to aging, exposure to the sun ...

  9. Virtual lesion extension : a measure to quantify the effects of bacterial blight on rice leaf CO2 exchange

    NARCIS (Netherlands)

    Elings, A.; Rossing, W.A.H.; Werf, van der W.

    1999-01-01

    Virtual lesion extension was proposed as a measure to summarize the effects of foliar diseases with single spreading lesions on CO2-exchange parameters at the whole-leaf level. Visible lesion plus virtual lesion extension constitute a virtual lesion, in which CO2 exchange was postulated to be nil.

  10. Bacterial succession on decomposing leaf litter exhibits a specific occurrence pattern of cellulolytic taxa and potential decomposers of fungal mycelia

    Czech Academy of Sciences Publication Activity Database

    Tláskal, Vojtěch; Voříšková, Jana; Baldrian, Petr

    2016-01-01

    Roč. 92, č. 11 (2016), fiw177 ISSN 0168-6496 R&D Projects: GA ČR GAP504/12/1288; GA MŠk(CZ) LM2015055 Institutional support: RVO:61388971 Keywords : bacteria * leaf litter * decomposition Subject RIV: EE - Microbiology, Virology Impact factor: 3.720, year: 2016

  11. Ethylene inhibitor aminoethoxyvinilglycine on glomerella leaf spot in apple cultivar 'Royal Gala' Inibidor de etileno aminoetoxivinilglicina sobre a mancha foliar de 'Glomerella' na cultivar de macieira 'Royal Gala'

    Directory of Open Access Journals (Sweden)

    Amauri Bogo

    2011-06-01

    Full Text Available Aqueous solution of Aminoethoxyvinylglycine (AVG has been commercialized in Brazil as ReTainTM C, 15% mainly as a potent inhibitor of ethylene biosynthesis by prevention of pre-harvest abscission and ripening of apple fruits. The effect of the product was evaluated during the 2007-08 and 2008-09 crop seasons in edafoclimatic conditions of Santa Catarina upland. Plants of 'Royal Gala' cultivar were sprayed with ReTainTM C, four weeks before the first commercial harvest at doses of 0; 62,5; 125, and 250mg a.i L-1. The incidence and severity were quantified weekly in 100 leaves distributed in four branches with 12 replications and assessed the area under the incidence -I and severity -S disease progress curve (AUIDPC and AUSDPC of Glomerella leaf spot (GLS. The AUIDPC and AUSDPC were significantly higher after AVG application and although there was no significant difference between 125 and 250mg a.i L-1 doses in both 2007-08 and 2008-09 crop seasons. In general, the symptoms of GLS (e.g. chlorosis, necrosis increased between the fourth and eighth week after application.Solução aquosa de Aminoetoxivinilglicina (AVG tem sido comercializada no Brasil como ReTainTM C, 15%, principalmente como um potente inibidor da biossíntese do etileno na prevenção da abscisão e maturação de frutos em macieira. O efeito do produto foi avaliado durante as safras 2007-08 e 2008-09 nas condições edafo-climáticas do planalto Catarinense. Plantas de maçãs 'Royal Gala' foram pulverizadas com o ReTainTM C, quatro semanas antes da primeira colheita comercial, nas concentrações de 0;62,5; 125 e 250mg i.a L-1. A incidência e a severidade foram quantificadas semanalmente em 100 folhas, distribuídas em quatro ramos por plantas, com 12 repetições e calculado a área abaixo da curva do progresso da incidência -I e severidade -S da doença (AACPID e AACPSD. A AACPID e AACPSD foram significativamente maiores após a aplicação do AVG e não houve diferen

  12. Fungitoxicidade de grupos químicos sobre Myrothecium roridum in vitro e sobre a mancha-de-mirotécio em algodoeiro Fungitoxicity of chemical groups on Myrothecium roridum in vitro and on myrothecium leaf spot on cotton plants

    Directory of Open Access Journals (Sweden)

    Juliano César da Silva

    2006-05-01

    Full Text Available O objetivo deste trabalho foi avaliar a fungitoxicidade de produtos pertencentes aos grupos dos benzimidazóis, triazóis, estrobilurinas, isoftalonitrilas e ditiocarbamatos sobre a germinação conidial e o crescimento micelial in vitro de isolados de Myrothecium roridum e, in vivo, sobre a severidade da mancha-de-mirotécio em plantas de algodoeiro. Nos testes in vitro os fungicidas foram solubilizados em meio BDA, utilizando-se as concentrações de 0,1, 1, 10 e 100 mg L-1 de ingrediente ativo. A fungitoxidade dos produtos foi avaliada por meio da ED50 (dose necessária para inibir 50% da germinação conidial ou crescimento micelial. Em casa de vegetação, estimou-se a severidade da mancha-de-mirotécio pela porcentagem de área foliar lesionada nas plantas de algodoeiro tratadas antes (preventivo e depois (curativo da inoculação do patógeno. Os fungicidas tiofanato metílico, carbendazim, metconazol, tiofanato metílico + clorotalonil, piraclostrobina + epoxiconazol, piraclostrobina + metiram, triflostrobina + propiconazol e tebuconazol inibiram com alta eficácia (ED50The objective of this work was to evaluate the toxicity of benzimidazoles, triazoles, strobilurins, isoftalonitrils and ditiocarbamats on Myrothecium roridum conidial germination and micelial growth in vitro, and the myrothecium leaf spot severity on cotton plants. On in vitro tests, fungicides were solubilized in PDA media at the following concentrations: 0.1, 1, 10 and 100 mg L-1. The toxicity of the products were evaluated by the ED50 rate (required for inhibiting 50% of the conidial germination or mycelial growth. In greenhouse tests, the severity of myrothecium leaf spot was quantified by measuring the leaf area affected by the pathogen in cotton plants sprayed before (preventive and after (curative the pathogen inoculation. The fungicides thiophanate methyl, carbendazim, metconazole, thiophanate methyl + chlorothalonil, pyraclostrobin + epoxyconazole, pyraclostrobin

  13. Roth spots in pernicious anaemia

    OpenAIRE

    Macauley, Mavin; Nag, Satyajit

    2011-01-01

    Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B12 injections resulted in complete resolution of the anaemia and Roth spots. The author...

  14. An operon for production of bioactive gibberellin A4 phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola.

    Science.gov (United States)

    Nagel, Raimund; Turrini, Paula C G; Nett, Ryan S; Leach, Jan E; Verdier, Valérie; Van Sluys, Marie-Anne; Peters, Reuben J

    2017-05-01

    Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the GA phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid-mediated defense response. Here the functions of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae is investigated in over 100 isolates. The Xoc operon leads to production of the bioactive GA 4 , an additional step beyond production of the penultimate precursor GA 9 mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (> 90%), but absent in the other major X. oryzae pathovar. These results indicate selective pressure for production of GA 4 in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  15. Quantitative trait loci associated with resistance to gray leaf spot and grain yield in corn QTLs associados à resistência a cercosporiose e produção de grãos em milho

    Directory of Open Access Journals (Sweden)

    Adriano Delly Veiga

    2012-02-01

    Full Text Available The main objectives of hybrid development programs include incorporating genetic resistance to diseases and increasing grain yield. Identification of Quantitative Trait Loci (QTL through the statistical analysis of molecular markers allows efficient selection of resistant and productive hybrids. The objective of this research was to identify QTL associated with resistance to gray leaf spot and for grain yield in the germplasm of tropical corn. We used two strains with different degrees of reaction to the disease; the genotypes are owned by GENESEEDS Ltda, their F1 hybrid and the F2 population. The plants were evaluated for gray leaf spot resistance, for grain yield and were genotyped with 94 microsatellite markers. Association of the markers with the QTL was performed by single marker analysis using linear regression and maximum likelihood analysis. It was observed that the additive effect was predominant for genetic control of resistance to gray leaf spot, and the dominant effect in that of grain yield. The most promising markers to be used in studies of assisted selection are: umc2082 in bins 4.03 and umc1117 in bins 4.04 for resistance to gray leaf spot; for grain yield umc1042 in bins 2.07 and umc1058 in bins 4.11.A incorporação de resistência genética a doenças e o aumento na produtividade de grãos estão entre os principais objetivos dos programas de desenvolvimento de híbridos. A identificação de locos de caracteres quantitativos (QTL por meio de análises estatísticas associadas a marcadores moleculares possibilita a rápida obtenção de híbridos resistentes e produtivos. Nesta pesquisa, objetivou-se identificar locos de caracteres quantitativos (QTL associados com resistência à cercosporiose e com produção de grãos em germoplasma de milho tropical. Foram utilizadas duas linhagens contrastantes em níveis de reação à doença (genótipos pertencentes à GENESEEDS - Ltda, seu híbrido F1 e a população segregante F2

  16. Generation of an Infectious Clone of a New Korean Isolate of Apple chlorotic leaf spot virus Driven by Dual 35S and T7 Promoters in a Versatile Binary Vector

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    Ik-Hyun Kim

    2017-12-01

    Full Text Available The full-length sequence of a new isolate of Apple chlorotic leaf spot virus (ACLSV from Korea was divergent, but most closely related to the Japanese isolate A4, at 84% nucleotide identity. The full-length cDNA of the Korean isolate of ACLSV was cloned into a binary vector downstream of the bacteriophage T7 RNA promoter and the Cauliflower mosaic virus 35S promoter. Chenopodium quinoa was successfully infected using in vitro transcripts synthesized using the T7 promoter, detected at 20 days post inoculation (dpi, but did not produce obvious symptoms. Nicotiana occidentalis and C. quinoa were inoculated through agroinfiltration. At 32 dpi the infection rate was evaluated; no C. quinoa plants were infected by agroinfiltration, but infection of N. occidentalis was obtained.

  17. Comparative transcriptome proifling of two maize near-isogenic lines differing in the allelic state for bacterial brown spot disease resistance

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-jun; Xu Li; ZHAO Pan-feng; LI Na; WU Lei; HE Yan; WANG Shou-cai

    2015-01-01

    The bacterial brown spot disease (BBS), caused primarily by Pseudomonas syringae pv. syringae van Hal (Pss), reduces plant vigor, yield and quality in maize. To reveal the nature of the defense mechanisms and identify genes involved in the effective host resistance, the dynamic changes of defense transcriptome triggered by the infection of Pss were investigated and compared between two maize near-isogenic lines (NILs). We found that Pss infection resulted in a sophisticated tran-scriptional reprogramming of several biological processes and the resistant NIL employed much faster defense responses than the susceptible NIL. Numerous genes encoding essential components of plant basal resistance would be able to be activated in the susceptible NIL, such as PEN1, PEN2, PEN3, and EDR1, however, in a basic manner, such resistance might not be sufifcient for suppressing Pss pathogenesis. In addition, the expressions of a large number of PTI-, ETI-, PR-, and WRKY-related genes were pronouncedly activated in the resistant NIL, suggesting that maize employ a multitude of defense pathways to defend Pss infection. Six R-gene homologs were identiifed to have signiifcantly higher expression levels in the resistant NIL at early time point, indicating that a robust surveil ance system (gene-to-gene model) might operate in maize during Pss attacks, and these homolog genes are likely to be potential candidate resistance genes involved in BBS disease resistance. Furthermore, a holistic group of novel pathogen-responsive genes were deifned, providing the repertoire of candidate genes for further functional characterization and identiifcation of their regulation patterns during pathogen infection.

  18. Roth spots in pernicious anaemia.

    Science.gov (United States)

    Macauley, Mavin; Nag, Satyajit

    2011-04-19

    Roth spots are white-centred retinal haemorrhages, previously thought to be pathognomonic for subacute bacterial endocarditis. A number of other conditions can be associated with Roth spots. In this case, the authors describe the association of Roth spots and pernicious anaemia. This association has been rarely described in the medical literature. Correct diagnosis and treatment with intramuscular vitamin B(12) injections resulted in complete resolution of the anaemia and Roth spots. The authors hope to alert clinicians to think of various differentials of Roth spots, and initiate prompt investigation and management.

  19. Efeito de produtos químicos e biológicos sobre a mancha bacteriana, flora microbiana no filoplano e produtividade de pimentão Effects of chemical and biological products on bacterial spot, microbial flora and yield in bell pepper

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    Débora AG da Silva

    2006-06-01

    Itaipu and Magali R. The study was carried out under field conditions from May to December 2002. A randomized complete block experimental design was used with four replications in a 4 x 3 factorial design. Weekly assessments were made for plant height (cm; number of stems; total number of leaves; number of fallen leaves; number of leaves with visible symptoms; damaged leaf area (severity, and yield (t ha-1. The microbial population resident in the phyloplan and fruits was quantified at the same time. There was no effect of treatments on yield, but an effect was observed on plant growth, on leaf spot and on the microbial flora. Copper oxychloride inhibited plant development, reduced number of fallen leaves and decreased the bacterial flora. Agrobio stimulated plant growth and, like streptomycin sulfate + oxytetracycline, inhibited the bacterial population, except Bacillus sp., and fungi, except Cladosporium sp. in the phyloplan. Among the genotypes, the hybrid Magali R was significantly superior in plant vigor, yield and resistance to bacterial spot. The results suggest bactericidal activity of the Agrobio under field conditions.

  20. Bacterially produced Pt-GFP as ratiometric dual-excitation sensor for in planta mapping of leaf apoplastic pH in intact Avena sativa and Vicia faba.

    Science.gov (United States)

    Geilfus, Christoph-Martin; Mühling, Karl H; Kaiser, Hartmut; Plieth, Christoph

    2014-01-01

    Ratiometric analysis with H(+)-sensitive fluorescent sensors is a suitable approach for monitoring apoplastic pH dynamics. For the acidic range, the acidotropic dual-excitation dye Oregon Green 488 is an excellent pH sensor. Long lasting (hours) recordings of apoplastic pH in the near neutral range, however, are more problematic because suitable pH indicators that combine a good pH responsiveness at a near neutral pH with a high photostability are lacking. The fluorescent pH reporter protein from Ptilosarcus gurneyi (Pt-GFP) comprises both properties. But, as a genetically encoded indicator and expressed by the plant itself, it can be used almost exclusively in readily transformed plants. In this study we present a novel approach and use purified recombinant indicators for measuring ion concentrations in the apoplast of crop plants such as Vicia faba L. and Avena sativa L. Pt-GFP was purified using a bacterial expression system and subsequently loaded through stomata into the leaf apoplast of intact plants. Imaging verified the apoplastic localization of Pt-GFP and excluded its presence in the symplast. The pH-dependent emission signal stood out clearly from the background. PtGFP is highly photostable, allowing ratiometric measurements over hours. By using this approach, a chloride-induced alkalinizations of the apoplast was demonstrated for the first in oat. Pt-GFP appears to be an excellent sensor for the quantification of leaf apoplastic pH in the neutral range. The presented approach encourages to also use other genetically encoded biosensors for spatiotemporal mapping of apoplastic ion dynamics.

  1. Elaboração e validação de escala diagramática para a cercosporiose do pimentão Development and validation of a diagrammatic key for Cercospora leaf spot of sweet pepper

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    Sami Jorge Michereff

    2006-09-01

    Full Text Available A cercosporiose do pimentão, causada pelo fungo Cercospora capsici, é uma importante doença que ocorre em condições tropicais. Devido à inexistência de métodos padronizados para quantificação desta doença em campo, uma escala diagramática com os níveis de 1,5; 3,5; 8,0; 16,5; 31,0 e 50% de área foliar lesionada foi elaborada e testada para a acurácia, a precisão e a reprodutibilidade das estimativas de severidade da cercosporiose do pimentão, sem e com a sua utilização. Na validação da escala diagramática, 50 folhas com diferentes níveis de severidade da doença, mensurados previamente com o programa AutoCAD®, foram avaliadas por 13 avaliadores, sem e com a utilização da escala diagramática. Foram realizadas duas avaliações com utilização da escala, com intervalo de sete dias, onde seqüências diferentes das mesmas folhas foram estimadas visualmente pelos mesmos avaliadores. A acurácia e a precisão de cada avaliador foi determinada por regressão linear simples, entre a severidade real e a estimada. Sem a escala, oito avaliadores superestimaram significativamente a severidade da doença. Com a escala, os avaliadores obtiveram melhores níveis de acurácia e precisão, embora quatro tendessem a superestimar a severidade, com os erros absolutos concentrando-se abaixo de 10%. Os avaliadores apresentaram boa repetibilidade e elevada reprodutibilidade das estimativas com a utilização da escala, o mesmo não sendo verificado sem a utilização desta. A escala diagramática proposta mostrou-se adequada para avaliação da severidade da cercosporiose do pimentão.Cercospora leaf spot of sweet pepper caused by the fungus Cercospora capsici is an important disease occurring in tropical conditions. Due to the inexistence of standard methods to quantify this disease in field conditions, a diagrammatic key including the levels 1.5, 3.5, 8.0,16.5, 31.0 and 50.0% of diseased leaf area was elaborated and tested for accuracy

  2. Reação de cultivares de trigo à ferrugem da folha e mancha amarela e responsividade a fungicidas Reaction of wheat cultivars to leaf rust and yellow spot and responsiveness to fungicides

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    Nédio Rodrigo Tormen

    2013-02-01

    Full Text Available Com o objetivo de avaliar a reação de cultivares de trigo à ferrugem da folha, causada por Puccinia triticina, e mancha amarela, causada por Drechslera tritici-repentis, e sua responsividade ao controle químico com fungicidas, foi conduzido experimento de campo durante os invernos de 2009 e 2010, Itaara-RS. As cultivares avaliadas foram 'FCEP 51', 'FCEP 52', 'CD 114', 'FCEP Campo Real', 'FCEP Cristalino', 'FCEP Nova Era', 'OR Marfim', 'OR Abalone', 'OR Safira' e 'OR Pampeano'; na safra 2010, a cultivar 'CD 114' foi substituída pela OR Quartzo. Os tratamentos avaliados foram: P1 - testemunha sem aplicação de fungicida; P2 - fempropimorfe (560g ha-1 de i.a.; P3 - azoxistrobina + ciproconazol (60+24g ha-1 de i.a.; e P4 - piraclostrobina + metconazol (60+97,5g ha-1 de i.a.. Após a segunda aplicação, efetuaram-se avaliações semanais de severidade das doenças, cujos dados foram utilizados para o cálculo da Área Abaixo da Curva de Progresso da Doença (AACPD. Também foram determinados a produtividade e o peso do hectolitro. No que se refere à suscetibilidade às doenças, as cultivares estudadas apresentaram respostas distintas de um ano para o outro. Para ferrugem, o comportamento mostrou-se similar em ambos os anos, enquanto que, para mancha amarela, houve variação. Quanto à resposta ao controle químico, ocorreram variações de acordo com o patógeno e com o grau de suscetibilidade das cultivares. O uso integrado de resistência genética e controle químico mostrou-se mais efetivo para ferrugem da folha.Aiming to evaluate the susceptibility of wheat cultivars to leaf rust and yellow spot and their responsiveness to chemical fungicides, two field trials were carried out, during 2009 and 2010 winter's. The cultivars evaluated were: 'FCEP 51', 'FCEP 52', 'CD114', 'FCEP Campo Real', 'FCEP Cristalino', 'FCEP Nova Era', 'OR Marfim', 'OR Abalone', 'OR Safira' and 'OR Pampeano'. In 2010, the 'CD 114' cultivar was replaced by Quartzo

  3. The Efficiency of Noni (Morinda citrifolia L.) Essential Oil on the Control of Leaf Spot Caused by Exserohilum turcicum in Maize Culture.

    Science.gov (United States)

    Silva, Janaina Costa E; Mourão, Dalmarcia de Sousa Carlos; Lima, Fabia Silva de Oliveira; Sarmento, Renato de Almeida; Dalcin, Mateus Sunti; Aguiar, Raimundo Wagner de Souza; Santos, Gil Rodrigues Dos

    2017-08-14

    The objective of this work was to evaluate the efficiency of noni essential oil on the control of Exserohilum turcicum , a causative agent of Exserohilum spot in maize culture. In the sanitary test 400 seeds were incubated using the blotter test method. For the transmissibility test, the fragments of damaged leaves of seedlings were removed and put into a potato, dextrose and agar (PDA) culture environment. To verify the pathogenicity, Koch´s postulates were performed. In the phytotoxicity test different concentrations of noni oil were applied in maize seedlings. E. turcicum conidia were submitted to different concentrations of noni oil. In the preventive and curative tests noni essential oils were applied before and after the conidia inoculation, respectively. The results revealed the presence of fungi of the genres Aspergillus , Penicillium , Rhizopus , Fusarium , and Exserohilum in the maize seeds. The pathogenicity of E. turcicum and also the transmission of this fungus from the seeds to the maize seedlings was confirmed. The inhibition of conidia germination was proportional to the concentration increase. The preventive application of noni essential oil was the most efficient on the control of Exserohilum spot.

  4. Atividades de quitinase e beta-1,3-glucanase após eliciação das defesas do tomateiro contra a mancha-bacteriana Chitinase and beta-1,3-glucanase activities after the elicitation of tomato defenses against bacterial spot

    Directory of Open Access Journals (Sweden)

    Fábio Rossi Cavalcanti

    2006-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência de eliciadores biológicos e químicos sobre as atividades de duas proteínas relacionadas à patogênese (PR, quitinase e beta-1,3-glucanase, em folhas de tomateiro, e avaliar o potencial desses eliciadores na redução do progresso da mancha-foliar causada por Xanthomonas campestris pv. vesicatoria. Plantas de tomateiro da cultivar Santa Cruz Kada foram pulverizadas com: acibenzolar-S-metil (ASM; 0,2 g L-1; formulação biológica proveniente de biomassa cítrica, denominada Ecolife (5 mL L-1; suspensão de quitosana (MCp; 200 g L-1, proveniente de micélio de Crinipellis perniciosa; extrato aquoso de ramos de lobeira (Solanum lycocarpum infectados por C. perniciosa (VLA; 300 g L-1. As plantas foram desafiadas com um isolado virulento da bactéria, quatro dias depois das pulverizações. Plantas pulverizadas com extratos biológicos mostraram redução da mancha-bacteriana. ASM proporcionou 49,3% de proteção, e foi igual à MCp e Ecolife e superior ao VLA. Este último não diferiu significativamente de MCp e Ecolife. Observou-se maior atividade das duas enzimas nas plantas tratadas, principalmente nas primeiras horas após as pulverizações.The objective of this work was to assess the influence of foliar application of resistance inducers and the activation of plant pathogenesis-related (PR proteins, chitinases and beta-1,3-glucanases, against Xanthomonas campestris pv. vesicatoria, and evaluate the potential of these elicitors on the reduction of bacterial leaf spot. Tomato plants of the cultivar Santa Cruz Kada were sprayed with: acibenzolar-S-methyl (0.2 g L-1 ASM; Ecolife, a biological formulation based on citric biomass (5 mL L-1; chitosan suspension from Crinipellis perniciosa mycelium (MCp; 200 g L-1; an aqueous extract from branches of lobeira (Solanum lycocarpum infected with C. perniciosa (VLA; 300 g L-1. Plants were challenged with a virulent bacterial strain four days after

  5. Melhoramento do feijoeiro comum com grão tipo carioca, visando resistência à antracnose e à mancha angular Breeding of common bean with carioca type grain for the resistance to anthracnose and angular leaf spot

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    Mansuêmia Alves Couto

    2008-10-01

    Full Text Available Objetivou-se no trabalho, selecionar linhagens de feijoeiro comum que reunissem, além da alta produtividade, porte ereto e grãos do tipo Carioca, também a resistência à antracnose e à mancha angular. O material experimental constituiu-se de 143 linhagens oriundas de três famílias segregantes F1:4RC2 {[(G2333 X ESAL 696 X ESAL 696] X CI 140}. Foram conduzidos quatro experimentos em três localidades da região sul de Minas Gerais, avaliando-se a produção, o tipo de grão, o porte e a reação à mancha angular. A reação à antracnose foi determinada a partir de inoculações de plantas jovens de cada linhagem, com as raças 2047 e 1545, mantidas em câmara de nevoeiro por três dias e transferidas para casa de vegetação com irrigação por aspersão, a cada quatro horas. Selecionaram-se quatro linhagens com alta produtividade, porte mais arbustivo, grãos tipo carioca e com resistência à mancha angular (nota até 4. Uma das linhagens selecionada possui o alelo Co-4², outras duas possuem o alelo Co-7 de resistência à antracnose e a última, embora seja suscetível à antracnose, possui resistência à mancha angular (nota 3,97 e maior produtividade de grãos.Aiming to select common bean lines with high grain yield, Carioca grain type, upright plant habit and resistant to anthracnose and angular leaf spot, 143 lines were selected from three families of the cross F1:4RC2 {[(G2333 X ESAL 696 X ESAL 696] X CI 140}. The promising lines were selected based on the agronomical traits in four field experiments, set up in three places in Southern MG State using the square lattice design. The reaction of each line to the anthracnose was evaluated by inoculating the seedlings using the races 1545 and 2047, and kept in humid chamber during three days, and then moved to greenhouse with sprinkle irrigation every four hours. Four lines with high grain yield, upright plant habit, Carioca grain type, and resistance to angular leaf spot (score up

  6. Seleção de famílias de feijoeiro resistente à antracnose e à mancha-angular Selection of common bean families resistant to anthracnose and angular leaf spot

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    Marcelo Geraldo de Morais Silva

    2006-10-01

    Full Text Available O objetivo deste trabalho foi identificar famílias de feijoeiro com resistência a Colletotrichum lindemuthianum e Phaeoisariopsis griseola e com outros fenótipos agronômicos desejáveis. As famílias utilizadas foram obtidas do cruzamento entre a linhagem H91, portadora de três alelos de resistência à antracnose, com três famílias F2:5 resistentes à mancha-angular, derivadas da cultivar Jalo EEP 558. Foi utilizado o delineamento látice quadrado em todos os experimentos. Inicialmente, foram avaliadas 144 famílias F2:3, no inverno de 2004, em Lavras, MG, com base no tipo de grão. Foram selecionadas 80 famílias F2:4 e avaliadas com a testemunha BRSMG Talismã, no período das águas de 2004/2005, no mesmo local. Considerando-se o tipo de grão e a resistência à mancha-angular e antracnose, foram mantidas 48 famílias F2:5, que foram avaliadas na seca de 2005, em Lavras e Lambari, MG. Essas 48 famílias passaram por inoculação das raças 2047, 73 e 1545 de C. lindemuthianum, para verificação da presença dos alelos de resistência Co-4², Co-5 e Co-7, respectivamente. Foram identificados genótipos da maioria das 48 famílias, quanto à reação à antracnose, das quais se destacaram quatro, em relação ao tipo de grão semelhante ao 'Carioca', de porte ereto, produtividade elevada e resistência à mancha-angular.The objective of this work was to select common bean families resistant to Colletotrichum lindemuthianum and Phaeoisariopsis griseola and, also, with superior agronomical traits. Families used were obtained from crosses of H91 lineage, bearer of three alleles resistant to anthracnose, and F2;5 families derived from the cultivar Jalo EEP 558, which is resistant to angular leaf spot. Square lattice design was used in all experiments. Initially the F2:3 families (144 were evaluated in the winter of 2004, in Lavras county, MG, Brazil, based on grain type. Eighty families (F2:4 were selected and evaluated with the check

  7. The efficacy of Carica papaya leaf extract on some bacterial and a fungal strain by well diffusion method

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    C. Baskaran

    2012-10-01

    Full Text Available Objective: To investigate the antimicrobial activity and phytochemical screening Ethanol, methanol, Ethyl acetate, acetone, chloroform, Petroleum ether, hexane, hot water, and extracts of Carica papaya. Methods: The aim of the present study was to evaluate the qualitative analysis of phytochemicals and antimicrobial activity of various solvent extracts of Carica papaya. The antimicrobial activities of different solvent extracts of Carica papaya were tested against the Gram-positive and Gram-negative bacterial strains and fungus by observing the zone of inhibition. The Gram-positive bacteria used in the test were Staphylococcus aureus, Bacillus cereus and Micrococcus luteus, and the Gram-negative bacteria were Escherichia coli, and Klebsiella pneumoniae, fungus like Aspergillus niger, Aspergillus flavus, Candida albicans, Candida tropicalis, Cryptococcus neoformans, and Candida kefyr. Results: It was observed that ethanol, methanol, ethyl acetate, aceton, chloroform, petroleum ether, hexane and aquas extracts showed activity against bacteria and fungus. The chloroform extract of Carica papaya showed more activity against Micrococcus luteus, zone of diameter 15.17暲0.29mm and acetone extract of Carica papaya showed more activity against Candida albicans, zone of diameter 11.23暲0.25mm compared to other solvent extracts. Conclusions: In this study chloroform extract in bacteria and acetone extract in fungus showed a varying degree of inhibition to the growth of tested organism, than Ethanol, methanol, Ethyl acetate, Petroleum ether, hexane and hot water extracts. The results confirmed the presence of antibacterial and antifungal activity of Carica papaya extract against various human pathogenic bacteria. Presences of phytochemical and antimicrobial activity are confirmed.

  8. Asparagus Beetle and Spotted Asparagus Beetle

    OpenAIRE

    Hodgson, Erin W.; Drost, Dan

    2007-01-01

    Asparagus beetle, Crioceris asparagi, and spotted asparagus beetle, C. duodecimpunctata are leaf beetles in the family Chrysomelidae. These beetles feed exclusively on asparagus and are native to Europe. Asparagus beetle is the more economically injurious of the two species.

  9. Effect of dietary supplementation of binahong leaf meal, betel nut meal or their combination on serum albumin and globulin, fecal endoparasites and bacterial counts in milk of Saanen goats suffering from subclinical mastitis

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    Endang Kusumanti

    2017-10-01

    Full Text Available The effect was investigated of dietary supplementation of binahong (Anredera cordifolia (Ten. Steenis leaf meal, betel nut (Arecha catechu L. meal or their combination on serum albumin and globulin, fecal endoparasites and bacterial counts in the milk of Saanen goats suffering from subclinical mastitis. The goats were randomly allotted to one of four experimental groups: control diet (diet without binahong leaf meal or betel nut meal; CON, diet supplemented with binahong leaf meal (1 g/kg body weight; BNH, diet supplemented with betel nut meal (1 g/kg body weight; BTN and diet supplemented with a combination of binahong leaf meal and betel nut meal (both 0.5 g/kg body weight; BNH + BTN. After 14 d treatment, the pH was higher (p  0.05 in levels of serum albumin and globulin and milk production across the treatment diets. In conclusion, dietary supplementation of binahong leaf meal, betel nut meal and a combination of both showed potential to reduce the load of endoparasites in the gastrointestinal tract and to reduce subclinical mastitis in lactating Saanen goats. Keywords: Antibiotics, Betel nut, Binahong, Saanen goat, Subclinical mastitis

  10. Induction of resistance to bacterial leaf blight (Xanthomonas oryzae) disease in the high yielding variety Vijaya (IR 8 x T 90)

    International Nuclear Information System (INIS)

    Padmanabhan, S.Y.; Kaur, S.; Rao, M.

    1976-01-01

    The high-yield variety Vijaya ( IR 8 x T 90), susceptible to bacterial leaf blight (Xanthomonas oryzae, Uyeda and Ishiyama Dawson), was treated with EMS to induce resistance. Dehusked seeds were pre-soaked in distilled water for 4 hrs, and subjected to 0.1% and 0.2% EMS for 6 hrs. Seed germination and survival was low in 0.2% EMS. Seedlings of M 1 were raised in pots, and panicles of individual plants harvested separately. The seeds of M 2 (8800 plants) generation were grown in nursery beds, and transplanted in field after 30 days. The plants were inoculated at the boot leaf stage with X.oryzae by the clipping method, and lesion length measured 15 days later. The frequency distribution of controls was bimodal, the EMS-treated population polymodal with new peaks. A wider range of variability was induced on the resistant and susceptible side. In M 2 0.36% resistant and 0.62% moderately resistant plants occurred. The seeds of (11) resistant and (20) moderately resistant plants of M 2 were sown for M 3 generation. These plants also segregated in the range of 0-31 and 0-32 cm lesion length. The frequency distribution curve was polymodal. M 2 from ''R'' showed 1.07% of resistant plants and 0.42% from ''MR'', against, 4.28% of moderately resistant plants from ''R'' and 3.22% from ''MR''. Susceptible plants of M 2 also segregated towards resistance (1.15%) and moderately resistant (6.96%) plants in M 3 generation. Resistant (25) and moderately resistant (147) plants of M 3 were carried forward to M 4 generation, and segregated in the range of 2.1-25 cm lesion length. The frequency curve was polymodal. No resistant plant (up to 2.0 cm lesion length) could be isolated in M 4 . The percentage of moderately resistant plants was 4.44% from ''R'' of M 3 and 4.82% from ''MR'' of M 3 and 4.77% from ''S'' of M 3 generation. The yield of resistant plants was low whereas the yield of moderately resistant plants equalled the parent; the yield of susceptible segregants equalled or

  11. Ação do biofertilizante Agrobio sobre a mancha-bacteriana e desenvolvimento de mudas de pimentão Effect of the Agrobio biofertilizer on the bacterial spot and the development of bell pepper transplants

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    Cláudia S.R. Deleito

    2005-03-01

    beneficial effect of Agrobio on bell pepper (Capsicum annuum L. transplants under greenhouse conditions. Two cultivars, 'Cascadura Ikeda' and 'Cascadura Itaipu' were used. Four Agrobio treatments, all diluted 5% (v/v in distilled water were used. They consisted of: (a raw; (b autoclaved (120ºC/20 min; (c filtered in millipore (0,22 µ diameter and (d the fraction retained on the millipore. They were applied as foliage sprays or directly on the substrate. As control treatments, oxytetracicline + streptomycin sulphate (0.8 g L-1, copper oxichloride (2.4 g L-1 and water were used. Raw of filtered Agrobio, as a foliage spray, resulted in better control of the disease and higher growth of the transplants, compared to autoclaved and fraction retained of the Agrobio and substrate sprays. All Agrobio treatments resulted in a less satisfactory disease control when compared to the commercial products, copper oxichloride and oxitetracicline + streptomycin sulphate, but more, effective than water. Agrobio stimulated the vegetative growth of the transplants, reduced the incidence of bacterial spot, increased the leaf area and promoted a better retention of infected leaves and the Bacillus spp. population.

  12. Survey and prevalence of species causing Alternaria leaf spots on brassica species in Pernambuco Levantamento e prevalência de espécies causadoras da alternariose em brássicas em Pernambuco

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    Sami J Michereff

    2012-06-01

    Full Text Available Brassicaceae family comprises plant species that are very important as vegetable crops, such as the species complex Brassica oleracea and Brassica rapa. Alternaria brassicicola and A. brassicae are among the most important pathogens of Brassicaceae causing Alternaria leaf spot disease. The occurrence and prevalence of Alternaria species causing leaf spots in brassica crops in Pernambuco was acessed, as well as the existence of a possible preference by vegetable host for these pathogens. Twenty-eight fields were surveyed in the Agreste region of Pernambuco state, in the 2005 and 2006 growing seasons. In each year, 10 Chinese cabbage, six cabbage, six cauliflower and six broccoli fields were visited. In each field, 50 leaves showing at least five lesions were randomly collected. Species identification was performed taking into account morphology of the conidia that was compared with literature data. Among the two Alternaria species found, A. brassicae was found in all Chinese cabbage fields while A. brassicicola was found in all fields of cabbage, cauliflower and broccoli. Overall, A. brassicicola was more prevalent than A. brassicae. In Chinese cabbage there was predominance of A. brassicae, with mean prevalence of 91.0% and 96.5% in 2005 and 2006. On the other hand, in broccoli and cabbage there was high predominance of A. brassicicola, with mean prevalence between 95.1% and 99.8%. In cauliflower, although the prevalence has been of A. brassicicola, high frequency of A. brassicae was noted. The frequency of co-occurrence of both Alternaria species was very low. The results of this study reinforce the hypothesis of existence of host preference within species of Alternaria that cause leaf spots in brassica crops, especially when Chinese cabbage, broccoli and cabbage are considered. This information is critical to developing strategies for managing Alternaria leaf spots in Brassicaceae species.A família Brassicaceae possui espécies importantes

  13. MultiLocus Sequence Analysis- and Amplified Fragment Length Polymorphism-based characterization of xanthomonads associated with bacterial spot of tomato and pepper and their relatedness to Xanthomonas species.

    Science.gov (United States)

    Hamza, A A; Robene-Soustrade, I; Jouen, E; Lefeuvre, P; Chiroleu, F; Fisher-Le Saux, M; Gagnevin, L; Pruvost, O

    2012-05-01

    MultiLocus Sequence Analysis (MLSA) and Amplified Fragment Length Polymorphism (AFLP) were used to measure the genetic relatedness of a comprehensive collection of xanthomonads pathogenic to solaneous hosts to Xanthomonas species. The MLSA scheme was based on partial sequences of four housekeeping genes (atpD, dnaK, efp and gyrB). Globally, MLSA data unambiguously identified strains causing bacterial spot of tomato and pepper at the species level and was consistent with AFLP data. Genetic distances derived from both techniques showed a close relatedness of (i) X. euvesicatoria, X. perforans and X. alfalfae and (ii) X. gardneri and X. cynarae. Maximum likelihood tree topologies derived from each gene portion and the concatenated data set for species in the X. campestris 16S rRNA core (i.e. the species cluster comprising all strains causing bacterial spot of tomato and pepper) were not congruent, consistent with the detection of several putative recombination events in our data sets by several recombination search algorithms. One recombinant region in atpD was identified in most strains of X. euvesicatoria including the type strain. Copyright © 2012 Elsevier GmbH. All rights reserved.

  14. Bier spots

    OpenAIRE

    Ahu Yorulmaz,; Seray Kulcu Cakmak; Esra Ar?; Ferda Artuz

    2015-01-01

    Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elu...

  15. 454-Pyrosequencing survey of microbiota in adult Spotted Wing Drosophila (SWD) corroborates a core microbiome and additional symbiotic and entomopathogenic bacterial associates

    Science.gov (United States)

    Complete surveys of insect endosymbionts including species of economic importance have until recently been hampered by a lack of high-throughput genetic assays. We used 454-pyrosequencing of the 16S rRNA gene amplicon of adult spotted wing Drosophila (SWD) Drosophila suzukii (Matsumura) from souther...

  16. The use of dried cerebrospinal fluid filter paper spots as a substrate for PCR diagnosis of the aetiology of bacterial meningitis in the Lao PDR

    OpenAIRE

    Elliott, I.; Dittrich, S.; Paris, D.; Sengduanphachanh, A.; Phoumin, P.; Newton, P.N.

    2013-01-01

    We investigated whether dried cerebrospinal fluid (CSF) conserved on filter paper can be used as a substrate for accurate PCR diagnosis of important causes of bacterial meningitis in the Lao PDR. Using mock CSF, we investigated and optimized filter paper varieties, paper punch sizes, elution volumes and quantities of DNA template to achieve sensitive and reliable detection of bacterial DNA from filter paper specimens. FTA Elute Micro Card? (Whatman, Maidstone, UK) was the most sensitive, cons...

  17. Characterization of rust, early and late leaf spot resistance in wild and cultivated peanut germplasm Caracterização da resistência à ferrugem, mancha preta e mancha castanha em germoplasma silvestre e cultivado de amendoim

    Directory of Open Access Journals (Sweden)

    Alessandra Pereira Fávero

    2009-02-01

    Full Text Available Groundnut (Arachis hypogaea has an AB genome and is one of the most important oil crops in the world. The main constraints of crop management in Brazil are fungal diseases. Several species of the genus Arachis are resistant to pests and diseases. The objective of our experiments was to identify wild species belonging to the taxonomic section Arachis with either A or B (or " non-A" genomes that are resistant to early leaf spot (Cercospora arachidicola, late leaf spot (Cercosporidium personatum and rust (Puccinia arachidis. For the identification of genotypes resistant to fungal diseases, bioassays with detached leaves were done in laboratory conditions, with artificial inoculation, a controlled temperature of 25ºC and a photoperiod of 10 h light/14 h dark, for 20-42 days, depending on the fungi species. Most of the accessions of wild species were more resistant than accessions of A. hypogaea for one, two or all three fungi species studied. Arachis monticola, considered to be a possible tetraploid ancestor or a derivative of A. hypogaea, was also more susceptible to Cercosporidium personatum and Puccinia arachidis, as compared to most of the wild species. Therefore, wild germplasm accessions of both genome types are available to be used for the introgression of resistance genes against three fungal diseases of peanut.O amendoim (Arachis hypogaea possui genoma AB e é uma das mais importantes culturas oleaginosas em todo o mundo. Os principais problemas da cultura no Brasil são as doenças fúngicas. Várias espécies do gênero Arachis são resistentes a pragas e doenças. Este trabalho visou a identificar espécies silvestres pertencentes à seção Arachis associadas aos genomas A ou B (ou " não-A" do amendoim que são resistentes à mancha castanha (Cercospora arachidicola, mancha preta (Cercosporidium personatum e ferrugem (Puccinia arachidis. Para a identificação de genótipos resistentes a doenças fúngicas, bioensaios utilizando

  18. Controle químico da mancha-bacteriana do tomate para processamento industrial em campo Field chemical control of bacterial spot on tomato for industrial processing

    Directory of Open Access Journals (Sweden)

    Abadia dos R Nascimento

    2013-03-01

    cloretos de benzalcônio. ASM e famoxadona + mancozebe foram os que promoveram uma relação benefício/custo superior a 1.In order to evaluate chemical control of bacterial spot on tomato for industrial processing, two field trials were carried out at the Unilever Bestfoods experimental station, in Goiânia, Goias state, Brazil. The first trial was in a randomized complete block design, with 15 treatments and three replications, using the hybrid Heinz 9992 inoculated with Xanthomonas perforans. The second trial was in a split-plot randomized complete block design with chemical foliar applications (10 treatments and hybrids (Hypeel 108 and U2006 as factors. Plants were inoculated with X. perforans and X. gardneri. In both trials the chemicals, in different number of applications and combinations, were: acibenzolar-S-methyl (ASM; famoxadone + mancozeb; metiram + pyraclostrobin; phosphite PK; benzalkonium chlorides; cuprous oxide, and copper hydroxide (SC, WP and WG. For both trials, disease severity on leaves, number of fruits with symptoms and yield were evaluated. In the second one, sunscald was also evaluated. For the first trial, significant severity differences (p>0.05 among treatments were observed only in the first two evaluations, but none of them differed from the water check control. In the second trial, significant differences were detected only in foliar severity in first evaluation for hybrids. For number of fruits with symptoms and sunscald, besides hybrids, interaction among factors was also significant. 'U2006' was more resistant than 'Hypeel 108', which also had highest sunscald values, but concerning fruits with symptoms, the opposite was observed. The two factors were significant for yield data, 'U2006' yielded better than 'Hypeel 108'. Despite none of the treatments have differed in yield from the water control, famoxadone + mancozeb, which resulted in the highest yield, differed from copper hydroxide, ASM - famoxadone + mancozeb, and benzalkonium

  19. Bier spots

    Directory of Open Access Journals (Sweden)

    Ahu Yorulmaz,

    2015-10-01

    Full Text Available Also called as physiologic anemic macules, Bier spots are small, hypopigmented irregularly shaped macules against a background of diffuse erythema, which creates an appearance of speckled vascular mottling of the skin. Bier spots most commonly appear on distal portions of the limbs though there are case reports describing diffuse involvement, which also affect trunk and mucous membranes of the patient. Although the exact pathophysiological mechanisms underlying Bier spots still need to be elucidated, Bier spots have been suggested to be a vascular anomaly caused by vasoconstriction of small vessels. In addition, several diseases have been proposed to be associated with Bier spots, including scleroderma renal crisis, cryoglobulinemia, Peutz-Jeghers syndrome, alopecia areata and hypoplasia of the aorta, although it has not been shown whether these associations are casual or coincidental. The clinical presentation of Bier spots is quite typical. These tiny whitish macules easily become prominent when the affected limb is placed in a dependent position and fade away when the limb is raised. Here we report a case of Bier spots in a 32-year-old male patient with characteristical clinical manifestations.

  20. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  1. Spotted inflation

    International Nuclear Information System (INIS)

    Matsuda, Tomohiro

    2010-01-01

    We describe new scenarios for generating curvature perturbations when inflaton (curvaton) has significant interactions. We consider a ''spot'', which arises from interactions associated with an enhanced symmetric point (ESP) on the trajectory. Our first example uses the spot to induce a gap in the field equation. We observe that the gap in the field equation may cause generation of curvature perturbation if it does not appear simultaneous in space. The mechanism is similar to the scenario of inhomogeneous phase transition. Then we observe that the spot interactions may initiate warm inflation in the cold Universe. Creation of cosmological perturbation is discussed in relation to the inflaton dynamics and the modulation associated with the spot interactions

  2. Bacterial diversity shift determined by different diets in the gut of the spotted wing fly Drosophila suzukii is primarily reflected on acetic acid bacteria

    KAUST Repository

    Vacchini, Violetta

    2016-11-25

    The pivotal role of diet in shaping gut microbiota has been evaluated in different animal models, including insects. Drosophila flies harbour an inconstant microbiota among which acetic acid bacteria (AAB) are important components. Here, we investigated the bacterial and AAB components of the invasive pest Drosophila suzukii microbiota, by studying the same insect population separately grown on fruit-based or non-fruit artificial diet. AAB were highly prevalent in the gut under both diets (90 and 92% infection rates with fruits and artificial diet, respectively). Fluorescent in situ hybridization and recolonization experiments with green fluorescent protein (Gfp)-labelled strains showed AAB capability to massively colonize insect gut. High-throughput sequencing on 16S rRNA gene indicated that the bacterial microbiota of guts fed with the two diets clustered separately. By excluding AAB-related OTUs from the analysis, insect bacterial communities did not cluster separately according to the diet, suggesting that diet-based diversification of the community is primarily reflected on the AAB component of the community. Diet influenced also AAB alpha-diversity, with separate OTU distributions based on diets. High prevalence, localization and massive recolonization, together with AAB clustering behaviour in relation to diet, suggest an AAB role in the D. suzukii gut response to diet modification. This article is protected by copyright. All rights reserved.

  3. Intensidade da cercosporiose da alface em cultivos convencionais e orgânicos em Pernambuco Intensity of Cercospora leaf spot of lettuce in conventional and organic farming systems in State of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Andréa Maria André Gomes

    2006-09-01

    Full Text Available Foram realizados levantamentos da intensidade da cercosporiose da alface, causada por Cercospora longissima, em 25 plantios manejados no sistema convencional e 25 no sistema orgânico, em dois períodos de plantio, janeiro-abril (I e junho-setembro (II de 2002, no estado de Pernambuco. A prevalência da doença foi elevada (> 88% em todas as situações avaliadas. Nas áreas de cultivo convencional a severidade da cercosporiose variou de 0,0 a 16,9%, enquanto em cultivos orgânicos de 0,0 a 22,5%. Nos dois sistemas de cultivo a severidade da doença foi significativamente mais elevada no período I, quando a precipitação pluviométrica foi quase três vezes superior ao período II. No entanto, somente no período II foram constatadas diferenças significativas na severidade da doença entre os sistemas de cultivo, sendo superior no sistema orgânico. Não foram constatadas correlações significativas entre os níveis de severidade da cercosporiose nas áreas de plantio nos dois períodos avaliados, dentro de cada sistema de cultivo.Surveys of the intensity of cercospora leaf spot of lettuce caused by Cercospora longissima were performed in 25 conventional and 25 organic farming areas in 2 planting periods, January-April (I and June-September (II 2002, in State of Pernambuco (Brazil. Disease prevalence was high (> 88% in all evaluated situations. Disease severity ranged from 0.0 to 16.9% in conventional farming areas and from 0.0 to 22.5% in organic farming areas. In both systems, disease severity was significantly higher in period I when precipitation was almost 3 times higher to that in period II. However, only in period II, significant differences in disease severity were found between farming systems, with high values in the organic system. There were no significant correlations among disease severity levels in the areas in both evaluated periods inside each farming system.

  4. White-centred retinal haemorrhages (Roth spots).

    OpenAIRE

    Ling, R.; James, B.

    1998-01-01

    Roth spots (white-centred retinal haemorrhages) were classically described as septic emboli lodged in the retina of patients with subacute bacterial endocarditis. Indeed many have considered Roth spots pathognomonic for this condition. More recent histological evidence suggests, however, that they are not foci of bacterial abscess. Instead, they are nonspecific and may be found in many other diseases. A review of the histology and the pathogenesis of these white-centred haemorrhages will be p...

  5. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  6. Identification of Causes of Red Leaf Spot on Red Jabon (Anthocephalus macrophyllus (Roxb. Havil Seeds in Kima Atas Permanent Nursery, Manado Forestry Research Institute (Identifikasi Penyebab Penyakit Bercak Merah Pada Bibit Jabon Merah (Anthocephalus Macrophyllus (Roxb. Havil di Persemaian Permanen Kima Atas, Balai Penelitian Kehutanan Manado

    Directory of Open Access Journals (Sweden)

    Hanif Nurul Hidayah

    2015-12-01

    Full Text Available Fulfillment the needs of Red Jabon (Anthocephalus macrophyllus (Roxb. Havil seeds on the other hand can create an unbalanced ecosystem. The availability of red Jabon seed was becoming a source of food for pests, then it causes an explosion of pests and pathogens. The disease that most often affect red Jabon seeds, both in the nursery and in the field was red leaf spot (antraknose. The initial step to control red leaf spot disease is the identification of causing. Identification method performed by observation of the symptoms in the field, followed by microscopic observation in a laboratory. Based on the identification result, it was known that the disease caused by the fungus Cercospora sp., Colletotrichum sp. and Pestalotia sp. The effect caused by those fungal pathogens was the disruption of the photosynthetic process that ultimately inhibits the growth of red Jabon seeds. The controls which have been done are arranged the watering intensity, isolated the infected seed,and  applied the chemical fungicide.

  7. ITS-rDNA phylogeny of Colletotrichum spp. causal agent of apple Glomerella leaf spot Filogenia por ITS-rDNA de Colletotrichum spp., agente causal da mancha foliar da Gala em macieira

    Directory of Open Access Journals (Sweden)

    Diorvania Ribeiro Giaretta

    2010-04-01

    Full Text Available Several diseases have affected apple production, among them there is Glomerella leaf spot (GLS caused by Colletotrichum spp. The first report of this disease in apple was in plants nearby citrus orchards in São Paulo State, Brazil. The origin of this disease is still not clear, and studies based on the molecular phylogeny could relate the organisms evolutionarily and characterize possible mechanisms of divergent evolution. The amplification of 5.8S-ITS (Internal Transcribed Spacer of rDNA of 51 pathogenic Colletotrichum spp. isolates from apples, pineapple guava and citrus produced one fragment of approximately 600 bases pairs (bp for all the isolates analyzed. The amplified fragments were cleaved with restriction enzymes, and fragments from 90 to 500bp were obtained. The sequencing of this region allowed the generation of a phylogenetic tree, regardless of their hosts, and 5 isolated groups were obtained. From the "in silico" comparison, it was possible to verify a variation from 93 to 100% of similarity between the sequences studied and the Genbank data base. The causal agent of GLS is nearly related (clustered to isolates of pineapple guava and to the citrus isolates used as control.A produção de maçã vem sendo comprometida pela ocorrência de muitas doenças, entre as quais se destaca a Mancha Foliar de Glomerella (MFG, causada por Colletotrichum spp. O primeiro relato dessa doença em maçã foi registrado em plantas próximas a pomares de citrus no Estado de São Paulo, Brasil. A origem da MFG ainda não está bem clara, e estudos baseados na filogenia permitirão relacionar o organismo evolutivamente, possibilitando caracterizar possíveis mecanismos divergentes de evolução. A amplificação da região 5.8S-ITS (espaçador interno transcrito do rDNA de 51 isolados de Colletotrichum patogênicos em de maçã, goiabeira serrana e citrus produziu um fragmento de aproximadamente 600 pares de bases (pb para todos os isolados analisados

  8. Optimization of single plate-serial dilution spotting (SP-SDS) with sample anchoring as an assured method for bacterial and yeast cfu enumeration and single colony isolation from diverse samples.

    Science.gov (United States)

    Thomas, Pious; Sekhar, Aparna C; Upreti, Reshmi; Mujawar, Mohammad M; Pasha, Sadiq S

    2015-12-01

    We propose a simple technique for bacterial and yeast cfu estimations from diverse samples with no prior idea of viable counts, designated as single plate-serial dilution spotting (SP-SDS) with the prime recommendation of sample anchoring (10 0 stocks). For pure cultures, serial dilutions were prepared from 0.1 OD (10 0 ) stock and 20 μl aliquots of six dilutions (10 1 -10 6 ) were applied as 10-15 micro-drops in six sectors over agar-gelled medium in 9-cm plates. For liquid samples 10 0 -10 5 dilutions, and for colloidal suspensions and solid samples (10% w/v), 10 1 -10 6 dilutions were used. Following incubation, at least one dilution level yielded 6-60 cfu per sector comparable to the standard method involving 100 μl samples. Tested on diverse bacteria, composite samples and Saccharomyces cerevisiae , SP-SDS offered wider applicability over alternative methods like drop-plating and track-dilution for cfu estimation, single colony isolation and culture purity testing, particularly suiting low resource settings.

  9. A TaqMan-based real time PCR assay for specific detection and quantification of Xylella fastidiosa strains causing bacterial leaf scorch in oleander.

    Science.gov (United States)

    Guan, Wei; Shao, Jonathan; Singh, Raghuwinder; Davis, Robert E; Zhao, Tingchang; Huang, Qi

    2013-02-15

    A TaqMan-based real-time PCR assay was developed for specific detection of strains of X. fastidiosa causing oleander leaf scorch. The assay uses primers WG-OLS-F1 and WG-OLS-R1 and the fluorescent probe WG-OLS-P1, designed based on unique sequences found only in the genome of oleander strain Ann1. The assay is specific, allowing detection of only oleander-infecting strains, not other strains of X. fastidiosa nor other plant-associated bacteria tested. The assay is also sensitive, with a detection limit of 10.4fg DNA of X. fastidiosa per reaction in vitro and in planta. The assay can also be applied to detect low numbers of X. fastidiosa in insect samples, or further developed into a multiplex real-time PCR assay to simultaneously detect and distinguish diverse strains of X. fastidiosa that may occupy the same hosts or insect vectors. Specific and sensitive detection and quantification of oleander strains of X. fastidiosa should be useful for disease diagnosis, epidemiological studies, management of oleander leaf scorch disease, and resistance screening for oleander shrubs. Published by Elsevier B.V.

  10. An HPLC-MS characterization of the changes in sweet orange leaf metabolite profile following infection by the bacterial pathogen Candidatus Liberibacter asiaticus.

    Science.gov (United States)

    Hijaz, Faraj M; Manthey, John A; Folimonova, Svetlana Y; Davis, Craig L; Jones, Shelley E; Reyes-De-Corcuera, José I

    2013-01-01

    Huanglongbing (HLB) presumably caused by Candidatus Liberibacter asiaticus (CLas) threatens the commercial U.S. citrus crop of an annual value of $3 billion. The earliest shift in metabolite profiles of leaves from greenhouse-grown sweet orange trees infected with Clas, and of healthy leaves, was characterized by HPLC-MS concurrently with PCR testing for the presence of Clas bacteria and observation of disease symptoms. Twenty, 8-month-old 'Valencia' and 'Hamlin' trees were grafted with budwood from PCR-positive HLB source trees. Five graft-inoculated trees of each variety and three control trees were sampled biweekly and analyzed by HPLC-MS and PCR. Thirteen weeks after inoculation, Clas was detected in newly growing flushes in 33% and 55% of the inoculated 'Hamlin' and 'Valencia' trees, respectively. Inoculated trees remained asymptomatic in the first 20 weeks, but developed symptoms 30 weeks after grafting. No significant differences in the leaf metabolite profiles were detected in Clas-infected trees 23 weeks after inoculation. However, 27 weeks after inoculation, differences in metabolite profiles between control leaves and those of Clas-infected trees were evident. Affected compounds were identified with authentic standards or structurally classified by their UV and mass spectra. Included among these compounds are flavonoid glycosides, polymethoxylated flavones, and hydroxycinnamates. Four structurally related hydroxycinnamate compounds increased more than 10-fold in leaves from 'Hamlin' and 'Valencia' sweet orange trees in response to Clas infection. Possible roles of these hydroxycinnamates as plant defense compounds against the Clas infection are discussed.

  11. Rocky Mountain spotted fever

    Science.gov (United States)

    ... spotted fever on the foot Rocky Mountain spotted fever, petechial rash Antibodies Deer and dog tick References McElligott SC, Kihiczak GG, Schwartz RA. Rocky Mountain spotted fever and other rickettsial infections. In: Lebwohl MG, Heymann ...

  12. White-centred retinal haemorrhages (Roth spots).

    Science.gov (United States)

    Ling, R; James, B

    1998-10-01

    Roth spots (white-centred retinal haemorrhages) were classically described as septic emboli lodged in the retina of patients with subacute bacterial endocarditis. Indeed many have considered Roth spots pathognomonic for this condition. More recent histological evidence suggests, however, that they are not foci of bacterial abscess. Instead, they are nonspecific and may be found in many other diseases. A review of the histology and the pathogenesis of these white-centred haemorrhages will be provided, along with the work-up of the differential diagnosis.

  13. Modelo agrometeorológico regional para estimativa da severidade da mancha de Phaeosphaeria em milho safrinha no Estado de São Paulo, Brasil Regional agrometeorological model to estimate Phaeosphaeria leaf spot severity on off-season maize crop in the State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Glauco de Souza Rolim

    2007-01-01

    Full Text Available O milho safrinha, cultivado no outono-inverno, no Estado de São Paulo, tem apresentado com freqüência significativas reduções de produtividade devidas à mancha foliar de Phaeosphaeria. Como estratégia para minimizar esses danos, os modelos agrometeorológicos de previsão de doenças podem auxiliar no planejamento e na tomada de decisões para o controle da doença na cultura. Dessa forma, este trabalho tem como objetivo o desenvolvimento e teste de modelos agrometeorológicos para previsão da porcentagem da área foliar afetada pela doença (%AFA em função do acúmulo diário de temperatura média e de chuva, em escala regional. Para tanto, foram utilizadas informações sobre a severidade da mancha de Phaeosphaeria em 158 cultivares de milho com diferentes níveis de resistência, durante a safrinha, em 14 diferentes localidades do Estado de São Paulo. Modelos foram desenvolvidos para cultivares suscetíveis, moderadamente resistentes e resistentes e os resultados indicaram haver boa performance na estimativa da %AFA, com altos valores de coeficiente de determinação (0,92; 0,81 e 0,83 respectivamente e índice de concordância de Willmott (0,98; 0,87; 0,94 respectivamente, além de teste F significativo a 1% de probabilidade para todos os casos. Os resultados também permitiram sugerir que a chuva e a temperatura são os fatores preponderantes para a ocorrência da mancha de Phaeosphaeria no Estado de São Paulo. Esses modelos têm a vantagem de utilizar variáveis usualmente obtidas em estações meteorológicas e poderão ser empregados em sistemas de alerta fitossanitários para monitoramento da doença no Estado.The off-season maize crop (named as "Safrinha" has been frequently suffering significant yield losses due to Phaeosphaeria leaf spot in state of São Paulo, Brazil. As a strategy for minimizing these losses, agrometeorological disease forecasting models can help in the planning and decision-making for disease control

  14. Seleção de linhagens de feijão rosinha de boa cocção, resistentes à antracnose e mancha angular Selection of pink grain common bean lines with good cooking ability, resistance to anthracnose and angular leaf spot

    Directory of Open Access Journals (Sweden)

    Diego Velásquez Faleiro e Silva

    2009-09-01

    Full Text Available Cultivares de feijoeiro com grão rosinha foram de grande importância, no passado, e ainda hoje, mesmo com a preferência pelo grão carioca, há nichos de mercado para feijões do grupo Rosinha. Dessa forma, o objetivo do trabalho foi selecionar linhagens de feijoeiro comum com grão rosinha, alta produção de grãos, rápido cozimento e resistentes à antracnose e à mancha angular. A partir de cinco famílias F8 superiores, provenientes do cruzamento entre os genitores Rosinha Maria da Fé e ESAL 693, foram extraídas 143 linhagens as quais foram avaliadas na safra das águas de 2005/2006 em Lavras (MG. Dessas, manteve-se 99 linhagens que foram avaliadas em Lavras e Lambari (MG, na safra da seca de 2006. As 24 linhagens selecionadas foram novamente avaliadas nos dois locais, no inverno de 2006. Os caracteres avaliados foram produção e tipo de grão, tempo de cocção, reação à mancha angular e também, foi realizado o teste de resistência ao patótipo 65 de Colletotrichum lindemuthianum. Nas linhagens, observaram-se variabilidade genética para todos os caracteres avaliados, altas estimativas dos coeficientes de herdabilidade, assegurando elevados ganhos com a seleção. Foram selecionadas quatro linhagens com alta produção, tipo de grão ideal, com rápido tempo de cocção e resistência à mancha angular e à antracnose.Common bean cultivars with pink grain type used to be very important, although there is still some market spot for them. The objective of the research was to select common bean lines with pink grain, high grain yield with good cooking ability, and resistance to anthracnose and angular leaf spot. One hundred and forty three lines were selected from five F8 segregant families derived from the cross Rosinha Maria da Fé x ESAL 693. Those lines were evaluated in the rainy season of 2005/2006 at Lavras county, MG State. Ninety nine lines were kept and tested in the dry season of 2006 at Lavras and Lambari. The 24

  15. Effect of crop density of two genotypes of maize in the severity of gray leaf spot and yield in the second season cropInfluência da densidade de cultivo de dois genótipos de milho na severidade da mancha de cercospora e no rendimento de grãos na safrinha

    Directory of Open Access Journals (Sweden)

    Luis Gustavo Amorim Pessoa

    2012-08-01

    Full Text Available Among the diseases that affect the corn crop and can reduce the yield, there is cercospora gray leaf, caused by Cercospora spp. This disease is very important in the second season crop or ‘safrinha’. The objective of this study was to evaluate the severity of cercospora leaf spot in transgenic corn hybrids Agroceres Yieldgard AG 9010 YG and Advance NK Agrisure TL (Bt11, using two plant densities: 78,000 and 100,000 plants per hectare. The results showed that the higher density of plants increased the severity of the disease and provided a lower yield. There was no significant interaction between hybrids and severity of the disease. Entre as doenças que incidem na cultura do milho e podem reduzir seu rendimento, há a mancha de cercospora, causada por Cercospora spp., especialmente importante em milho de segunda época, ou ‘safrinha’. O objetivo deste trabalho foi avaliar a severidade da cercosporiose em nos híbridos transgênicos de milho Agroceres Yieldgard AG 9010 YG e Advance NK Agrisure TL (Bt11, em duas densidades de cultivo: 78.000 e 100.000 plantas por hectare. Os resultados permitiram constatar que a menor densidade de plantas favoreceu o incremento da severidade da doença e proporcionou menor rendimento de grãos. Não houve interação significativa entre os híbridos e a severidade da doença.

  16. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... of typical analytical workloads and real spot price traces. SpotADAPT's suggested deployments are comparable to the theoretically optimal ones, and in particular, it shows good cost benefits for the budget optimization -- on average SpotADAPT is at most 0.3% more expensive than the theoretically optimal...

  17. Rapid differentiation of rocky mountain spotted fever from chickenpox, measles, and enterovirus infections and bacterial meningitis by frequency-pulsed electron capture gas-liquid chromatographic analysis of sera.

    Science.gov (United States)

    Brooks, J B; McDade, J E; Alley, C C

    1981-01-01

    Normal sera and sera from patients with Rocky Mountain spotted fever, chickenpox, enterovirus infections, measles, and Neisseria meningitidis infections were extracted with organic solvents under acidic and basic conditions and then derivatized with trichloroethanol or heptafluorobutyric anhydride-ethanol to form electron-capturing derivatives of organic acids, alcohols, and amines. The derivatives were analyzed by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). There were unique differences in the FPEC-GLC profiles of sera obtained from patients with these respective diseases. With Rocky Mountain spotted fever patients, typical profiles were detected as early as 1 day after onset of disease and before antibody could be detected in the serum. Rapid diagnosis of Rocky Mountain spotted fever by FPEC-GLC could permit early and effective therapy, thus preventing many deaths from this disease. PMID:7276147

  18. Rocky Mountain Spotted Fever

    Science.gov (United States)

    ... with facebook share with twitter share with linkedin Rocky Mountain Spotted Fever Credit: CDC A male cayenne tick, Amblyomma cajennense, ... and New Mexico. Why Is the Study of Rocky Mountain Spotted Fever a Priority for NIAID? Tickborne diseases are becoming ...

  19. Bacterial anoxygenic photosynthesis on plant leaf surfaces

    Czech Academy of Sciences Publication Activity Database

    Atamna-Ismaeel, N.; Finkel, O.; Glaser, F.; von Mering, Ch.; Vorholt, J. A.; Koblížek, Michal; Belkin, S.; Béja, O.

    2012-01-01

    Roč. 4, č. 2 (2012), s. 209-216 ISSN 1758-2229 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0110; GA ČR GAP501/10/0221 Institutional support: RVO:61388971 Keywords : phyllosphere * plant * phyllosphere Subject RIV: EE - Microbiology, Virology Impact factor: 2.708, year: 2012

  20. Antimicrobial activity of the aqueous, methanol and chloroform leaf ...

    African Journals Online (AJOL)

    The minimum inhibitory concentration (MIC) of methanol leaf extract show least activity against Yersinia enterocolitica and Pseudomonas aeruginosa (MIC = 100 mg/ml) and higher activity of MIC at 50 mg/ml against the other bacterial test organisms. The chloroform leaf extract MIC of 100 mg/ml had least activity against ...

  1. Resistance to stem canker, frogeye leaf spot and powdery mildew of soybean lines lacking lipoxigenases in the seeds Resistência ao cancro-da-haste, à cercosporiose e ao oídio de linhagens de soja sem lipoxigenases nas sementes

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Osório Martins

    2002-12-01

    Full Text Available The soybean [Glycine max (L. Merrill] crop holds a prominent position in the Brazilian economy because of the extension of the planted area and volume of grain production, but the beany flavor has been a limiting factor for soybean derivatives consumption by western population. This flavor is produced mainly by action of lipoxygenase enzymes (Lox1, Lox2 and Lox3, present in some commercial varieties. The genetic elimination of the alleles that codify these enzymes is the most appropriate way to avoid problems associated to this deleterious flavor. To elucidate the effect of seed lipoxygenase elimination on the resistance to plant pathogens, normal varieties of soybean (FT-Cristalina RCH, Doko RC and IAC-12 and their backcross-derived lines, both with the three lipoxygenases present in their seeds (triple-positive, TP and without the three lipoxygenases (triple-null, TN, were tested for their resistance to stem canker (Diaporthe phaseolorum f.sp. meridionalis, frogeye leaf spot (Cercospora sojina Hara, and powdery mildew (Microsphaera diffusa Cke. & Pk.. All genetic materials studied were resistant to stem canker. FT-Cristalina RCH and Doko-RC and their TP and TN lines were resistant to frogeye leaf spot. IAC-12 and its derived lines not only presented a higher disease index, but also the derived lines, TP and TN, were more susceptible, indicating the loss of genes for disease resistance in the backcrosses. There was no association between the elimination of lipoxygenases from the seeds with the resistance to frogeye leaf spot. In relation to the powdery mildew, TP or TN lines presented similar or higher resistance than their respective recurrent parents whose susceptibility appeared in the following order: IAC-12, less susceptible, Doko-RC, intermediate and FT-Cristalina RCH, more susceptible.A cultura da soja [Glycine max (L. Merrill] ocupa lugar de destaque na economia brasileira, tanto em termos de área plantada, quanto de produção de gr

  2. Characterization and fine mapping of a light-dependent leaf lesion mimic mutant 1 in rice.

    Science.gov (United States)

    Wang, Jing; Ye, Bangquan; Yin, Junjie; Yuan, Can; Zhou, Xiaogang; Li, Weitao; He, Min; Wang, Jichun; Chen, Weilan; Qin, Peng; Ma, Bintian; Wang, Yuping; Li, Shigui; Chen, Xuewei

    2015-12-01

    Plants that spontaneously produce lesion mimics or spots, without any signs of obvious adversity, such as pesticide and mechanical damage, or pathogen infection, are so-called lesion mimic mutants (lmms). In rice, many lmms exhibit enhanced resistance to pathogens, which provides a unique opportunity to uncover the molecular mechanism underlying lmms. We isolated a rice light-dependent leaf lesion mimic mutant 1 (llm1). Lesion spots appeared in the leaves of the llm1 mutant at the tillering stage. Furthermore, the mutant llm1 had similar agronomic traits to wild type rice. Trypan blue and diamiobenzidine staining analyses revealed that the lesion spot formation on the llm1 mutant was due to programmed cell death and reactive oxygen species. The chloroplasts were severely damaged in the llm1 mutant, suggesting that chloroplast damage was associated with the formation of lesion spots in llm1. More importantly, llm1 exhibited enhanced resistance to bacterial blight pathogens within increased expression of pathogenesis related genes (PRs). Using a map-based cloning approach, we delimited the LLM1 locus to a 121-kb interval between two simple sequence repeat markers, RM17470 and RM17473, on chromosome 4. We sequenced the candidate genes on the interval and found that a base mutation had substituted adenine phosphate for thymine in the last exon of LOC_Os04g52130, which led to an amino acid change (Asp(388) to Val) in the llm1 mutant. Our investigation showed that the putative coproporphyrinogen III oxidase (CPOX) encoded by LOC_Os04g52130 was produced by LLM1 and that amino acid Asp(388) was essential for CPOX function. Our study provides the basis for further investigations into the mechanism underlying lesion mimic initiation associated with LLM1. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  3. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  4. Spectral-domain optical coherence tomography of roth spots.

    Science.gov (United States)

    Giovinazzo, Jerome; Mrejen, Sarah; Freund, K Bailey

    2013-01-01

    To describe the retinal findings of subacute bacterial endocarditis, their evolution after treatment, and analysis with spectral-domain optical coherence tomography. Retrospective chart review. A 21-year-old man presented with the sudden onset of a central scotoma in his left eye because of a sub-internal limiting membrane hemorrhage overlying the left fovea. When examined 2 weeks later, Roth spots were noted in his right eye. The patient was immediately referred to his internist and diagnosed with subacute bacterial endocarditis with cultures positive for Streptococcus viridans. He subsequently underwent aortic valve replacement surgery after 4 weeks of intravenous antibiotic therapy. When examined 4 weeks after valve replacement surgery, there was regression of the Roth spots. The present case demonstrates the importance of a funduscopic examination in the early diagnosis and management of subacute bacterial endocarditis. The analysis of Roth spots with spectral-domain optical coherence tomography suggested that they were septic emboli.

  5. Studies on an X-ray induced crinkled leaf mutant of Trichosanthes anguina L

    International Nuclear Information System (INIS)

    Datta, Subodh Kumar

    1986-01-01

    Crinkled leaf mutant isolated in the second generation after treatment with X-ray bred true in subsequent generation. The mutant was a late flowering type with increased percentage of PMC's with chromosomal abnormality and pollen grain sterility. TLC study on phenolic compounds in leaves showed that both the mother line and the mutant had equal number of spots but they differed from each other with respect to four spots. Spot Nos. 2 and 4 of the mother line were absent in the mutant but the latter had two new spots (spot Nos. 11 and 12). The mutant and the mother line also differed from each other in pollen grain morohology. (author)

  6. Evaluation of banana hybrids for tolerance to black leaf streak (Mycosphaerella fijiensis Morelet) in Puerto Rico

    Science.gov (United States)

    In Puerto Rico, bananas (including plantains) are important agricultural commodities; their combined production totaled 133,500 tons in 2008. Black leaf streak (BLS) and Sigatoka leaf spot diseases, caused by Mycosphaerella fijiensis and M. musicola, respectively, are responsible for significant los...

  7. Incorporation of resistance to angular leaf spot and bean common ...

    African Journals Online (AJOL)

    Luseko

    2013-07-03

    Jul 3, 2013 ... indicating high reliability for markers. In selection, it was ... Generation of breeding lines. Planting was .... the variances from the distribution of the score data for ALS disease. ... were distributed along the scale but it skewed to the left side showing ..... Standard system for the evaluation of bean germplasm.

  8. Molecular variability analyses of Apple chlorotic leaf spot virus

    Indian Academy of Sciences (India)

    The highest degree of variability was observed in the middle portion with 9 amino acid substitutions in contrast to the N-terminal and C-terminal ends, which were maximally conserved with only 4 amino acid substitutions. In phylogenetic analysis no reasonable correlation between host species and/or geographic origin of ...

  9. Research Note Genetics of resistance to Cercospora leaf spot ...

    Indian Academy of Sciences (India)

    ACER

    2Cenler for Advanced Studies for Agriculturc and Food (CASAF), Kasetsart University. Institute for ... Generation mean analysis showed that a simple additive- ... Artificial inoculation was also carried out at 40 and 50 days after planting.

  10. Narrow sense heritability and gene effects for late leaf spot ...

    African Journals Online (AJOL)

    SM 03590, Valencia C × ICGV-SM 02501 and NuMex-M3 × ICGV-SM 02501 crosses, respectively. Both additive and dominance gene effects contributed significantly to the inheritance of LLS resistance in all the crosses, except in Redbeauty ...

  11. Molecular variability analyses of Apple chlorotic leaf spot virus ...

    Indian Academy of Sciences (India)

    Plant Virology Lab, Institute of Himalayan Bioresource Technology, Palampur 176 061, India ... to detect possible heterogeneity and evolution. 2. Materials and ..... of flower petals and buds. .... Recently, classification for ACLSV-CP based on.

  12. narrow sense heritability and gene effects for late leaf spot

    African Journals Online (AJOL)

    ACSS

    (33-55%) and protein (19- 31%) (Jambunathan,. 1991; Shilpa et ... information on non-allelic interactions for LLS resistance in ..... molecular breeding for rust resistance in groundnut ... Comperative simulation studies on the effect of selection.

  13. Isolation and identification of fungi responsible for leaf spots disease ...

    African Journals Online (AJOL)

    The diseased plant leaves were taken to the laboratory for culture, isolation, and ... These included; Alternaria longipes, Aspergillus fumigatus, Aspergillus niger, ... Phomopsis mangiferae, Pseudofusicoccum spp. and Rhizopus oryzae.

  14. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  15. Arc cathode spots

    International Nuclear Information System (INIS)

    Schrade, H.O.

    1989-01-01

    Arc spots are usually highly unstable and jump statistically over the cathode surface. In a magnetic field parallel to the surface, preferably they move in the retrograde direction; i.e., opposite to the Lorentzian rule. If the field is inclined with respect to the surface, the spots drift away at a certain angle with respect to the proper retrograde direction (Robson drift motion). These well-known phenomena are explained by one stability theory

  16. Diallel analysis of leaf disease resistance in inbred Brazilian popcorn cultivars.

    Science.gov (United States)

    Vieira, R A; Scapim, C A; Moterle, L M; Tessmann, D J; Conrado, T V; Amaral Júnior, A T

    2009-12-01

    We estimated general and specific combining abilities and examined resistance to northern leaf blight (Exserohilum turcicum) and to gray leaf spot (Cercospora zeae-maydis) in a set of nine inbred popcorn lines. These inbreds were crossed in a complete diallel scheme without reciprocals, which produced 36 F(1) hybrids. Two experiments with a square lattice design and three replications were conducted during the 2008/2009 crop season, in Maringá, PR, Brazil. The severity of northern leaf blight and gray leaf spot was assessed under natural infestation conditions. Data were examined by individual and joint analysis of variance. Individual and joint Griffing's diallel analyses were carried out for adjusted means. General combining ability and specific combining ability were significant (P < 0.10) by the F-test for northern leaf blight and gray leaf spot infestation levels. This denotes that additive and non-additive gene effects both contributed to resistance to these diseases, but that the additive gene effects were more important. Among the inbred lines, P(8) and P(9) gave the highest resistance to northern leaf blight, and P(3) and P(4.3) gave the highest resistance to gray leaf spot. The hybrids P(7.4) x P(8) and P(4.3) x P(9) could be exploited by reciprocal recurrent selection to provide genotypes with both northern leaf blight and gray leaf spot resistance. Significant interaction between general combining ability and crop season (P < 0.10) denotes the importance of environment, even though the disease levels in the hybrids were quite consistent.

  17. Identification of two new races of Diplocarpon rosae Wolf, the causal agent of rose black spot disease

    Science.gov (United States)

    The fungal pathogen, Diplocarpon rosae Wolf, infects only roses (Rosa spp.) and leads to rose black spot disease. Rose black spot is the most problematic disease of outdoor grown roses worldwide, due to the potential for rapid leaf yellowing and defoliation. Plants repeatedly defoliated from black ...

  18. Spilocaea pyracanthae causing leaf scab on loquat in Pakistan

    Directory of Open Access Journals (Sweden)

    Haris Butt

    2016-03-01

    Full Text Available ABSTRACT Loquat is attacked by many phytopathogenic fungi. Among these Spilocaea pyracanthae is of economic importance. The fungus received no attention in Pakistan and some other parts of the world. The current study is focused on the symptomatology of this disease and the etiology of the fungus. During extensive surveys of loquat orchards in 2013 heavy infestations of this disease were observed. The leaf symptoms were observed as olive brown, opaque necrotic sub-circular spots, with light brown coloration in the center. Two or more spots coalesced in severe infections covering large leaf areas. The fungus was identified as Spilocaea pyracanthae on the basis of conidia and morphological characters. The pathogenicity of the fungus was confirmed on healthy plants under greenhouse conditions by following Koch's postulates. The fungus produced characteristic leaf scab symptoms on young leaves. This is the first report of Spilocaea pyracanthae causing leafscab of loquat in Pakistan.

  19. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  20. Characterization of resistant tomato mutants to bacterial canker ...

    African Journals Online (AJOL)

    Yomi

    2012-04-19

    Apr 19, 2012 ... Cmm bacteria induce bacterial canker and wilt during infection. It is unknown ... are able to degrade plant cell walls and attack xylem vessels and ... seedlings were transferred into plastic pots at four to five true leaf stages.

  1. Characterizing and Estimating Fungal Disease Severity of Rice Brown Spot with Hyperspectral Reflectance Data

    Directory of Open Access Journals (Sweden)

    Zhan-yu LIU

    2008-09-01

    Full Text Available Large-scale farming of agriculture crops requires real-time detection of disease for field pest management. Hyperspectral remote sensing data generally have high spectral resolution, which could be very useful for detecting disease stress in green vegetation at the leaf and canopy levels. In this study, hyperspectral reflectances of rice in the laboratory and field were measured to characterize the spectral regions and wavebands, which were the most sensitive to rice brown spot infected by Bipolaris oryzae (Helminthosporium oryzae Breda. de Hann. Leaf reflectance increased at the ranges of 450 to 500 nm and 630 to 680 nm with the increasing percentage of infected leaf surface, and decreased at the ranges of 520 to 580 nm, 760 to 790 nm, 1550 to 1750 nm, and 2080 to 2350 nm with the increasing percentage of infected leaf surface respectively. The sensitivity analysis and derivative technique were used to select the sensitive wavebands for the detection of rice brown spot infected by B. oryzae. Ratios of rice leaf reflectance were evaluated as indicators of brown spot. R669/R746 (the reflectance at 669 nm divided by the reflectance at 746 nm, the following ratios may be deduced by analogy, R702/R718, R692/R530, R692/R732, R535/R746, R521/R718, and R569/R718 increased significantly as the incidence of rice brown spot increased regardless of whether it's at the leaf or canopy level. R702/R718, R692/R530, R692/R732 were the best three ratios for estimating the disease severity of rice brown spot at the leaf and canopy levels. This result not only confirms the capability of hyperspectral remote sensing data in characterizing crop disease for precision pest management in the real world, but also testifies that the ratios of crop reflectance is a useful method to estimate crop disease severity.

  2. Induced mutation for disease resistance in rice with special reference to blast, bacterial blight and tungro

    International Nuclear Information System (INIS)

    Mathur, S.C.

    1983-01-01

    Rice varieties Ratna, Pusa 2-21, Vijaya and Pankaj have been treated with gamma rays, EMS or sodium azide to improve their resistance against blast, bacterial leaf blight or tungro virus. For blast and tungro, mutants with improved resistance were selected. Variation in reaction to bacterial leaf blight has been used in crossbreeding to accumulate genes for resistance. (author)

  3. Maculosin, a host-specific phytotoxin for spotted knapweed from Alternaria alternata

    Science.gov (United States)

    Stierle, Andrea C.; Cardellina, John H.; Strobel, Gary A.

    1988-01-01

    Several diketopiperazines have been isolated from liquid cultures of Alternaria alternata, the causal agent of black leaf blight of spotted knapweed, Centaurea maculosa Lam. One of these compounds, maculosin [the diketopiperazine cyclo(-L-Pro-L-Tyr-)], was active in the nicked-leaf bioassay at 10-5 M; synthetic maculosin possessed chemical and biological activities identical to those of the natural product. Other diketopiperazines isolated from the fungus possessed either less activity or none at all. In tests against 19 plant species, maculosin was phytotoxic only to spotted knapweed. Thus maculosin is a host-specific phytotoxin from a weed pathogen. PMID:16593989

  4. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  5. Factors associated with negative T-SPOT.TB results among smear-negative tuberculosis patients in China.

    Science.gov (United States)

    Kang, Wanli; Wu, Meiying; Yang, Kunyun; Ertai, A; Wu, Shucai; Geng, Shujun; Li, Zhihui; Li, Mingwu; Pang, Yu; Tang, Shenjie

    2018-03-09

    We compared the positive rates of T-SPOT.TB and bacterial culture in the smear-negative PTB, and analyzed the factors affecting the results of negative T-SPOT.TB and bacterial culture. Retrospective evaluation of data from smear-negative PTB patients who underwent T-SPOT.TB and bacterial culture were done. The agreement and concordance were analyzed between T-SPOT.TB and bacterial culture. Multivariable logistic regression analysis was used to explore the factors associated with positive results of T-SPOT.TB and bacterial culture in smear-negative PTB. 858 eligible smear-negative PTB patients were included in the study. The agreement rate was 25.6% (22.7~28.5%) between T-SPOT.TB and bacterial culture in smear- negative PTB patients. The positive rate of T-SPOT.TB was higher than that of bacterial culture in smear-negative PTB patients (p SPOT.TB and bacterial culture (p > 0.05). Using multivariable logistic regression analysis we found that older age ≥ 60 years (OR = 0.469, 95% CI: 0.287-0.768) and decreased albumin (OR = 0.614, 95% CI: 0.380-0.992) were associated with negative diagnostic results of T-SPOT.TB in smear-negative PTB patients. Female (OR = 0.654, 95% CI: 0.431-0.992) were associated with negative diagnostic results of bacteria culture in smear-negative PTB patients. Our results indicated that the older age and decreased albumin were independently associated with negative T-SPOT.TB responses.

  6. Dinâmica temporal da mancha foliar da 'Gala' em macieiras conduzidas sob os sistemas de produção convencional e orgânico Temporal dynamic of 'Gala' leaf spot in apples under conventional and organic production systems

    Directory of Open Access Journals (Sweden)

    Amauri Bogo

    2010-02-01

    Full Text Available Este trabalho objetivou avaliar a dinâmica temporal da Mancha Foliar da 'Gala' em macieira nos sistemas convencional e orgânico de produção, em condições edafo-climáticas do Planalto Catarinense. A incidência e severidade foram quantificadas quinzenalmente, em 100 folhas, distribuídas em quatro ramos da cultivar 'Royal Gala' com 12 repetições, gerando 16 mapas em cada sistema de produção. A severidade foi avaliada de acordo com escala diagramática específica. Com os dados obtidos, foram plotadas curvas de progresso da doença, e as epidemias foram comparadas em relação à a início do aparecimento dos sintomas (IAS; b tempo para atingir a máxima incidência e severidade da doença (TAMID e TAMSD; c valor máximo de incidência e severidade da doença (Imax e Smax; e d área abaixo da curva de progresso da incidência e severidade da doença (AACPID e AACPSD. Os dados de incidência e severidade foram analisados por meio de análise de regressão linear simples, sendo ajustados para três modelos empíricos, Logístico, Monomolecular e Gompertz. A cultivar 'Royal Gala' foi suscetível ao Colletotrichum sp., e as maiores intensidades de doença foram registradas no sistema de produção orgânico. O modelo mais apropriado para descrever o progresso da doença foi o Logístico e, por meio do uso da incidência, não foram detectadas diferenças significativas entre os sistemas de produção, porém a taxa de progresso da severidade da doença foi significativamente maior no sistema de produção orgânico do que no convencional.This study aimed to evaluate the temporal dynamic of 'Gala' leaf spot under conventional and organic systems of production in edafoclimatic conditions of Santa Catarina plateau. The incidence and severity were quantified biweekly in 100 leaves distributed in four branches of the "Royal Gala" cultivar with 12 replications, generating 16 maps for each system of production. The disease severity was evaluated

  7. TV spots' impact.

    Science.gov (United States)

    El-bakly, S

    1994-09-01

    The Information, Education and Communication (IEC) Center of the State Information Service was established in 1979 for the purpose of providing information to the people on the population issue. The Ministry of Information has accorded the State Information Service free TV and radio air time for family planning dramas and spots. In the early years information campaigns were organized to make people aware of the population problem by slogans, songs, and cartoons. Around 1984 misconceptions about family planning and contraceptives were attacked through a number of TV and radio spots. A few years later 21 spots on specific contraceptive methods were broadcast which were aired for three years over 3000 times. They were extremely successful. The impact of these TV spots was one of the major reasons why the contraceptive prevalence rate increased from 30% in 1984 to 38% in 1988 and 47% in 1992. Spots were also broadcast about the social implications of large families. The TV soap opera "And The Nile Flows On", with the family planning message interwoven into it, was very well received by the target audience. A program entitled "Wedding of the Month" features couples who know family planning well. The most successful radio program is a 15-20 minute long quiz show for residents of the villages where the Select Villages Project is being implemented. The State Information Service has 60 local information centers in the 26 governorates of Egypt that make plans for the family planning campaign. In 1992 the Minya Initiative, a family planning project was implemented in the Minya Governorate. As a result, the contraceptive prevalence rate rose from 22% to 30% over 18 months. A new project, the Select Village Project, was developed in 1993 that replicates the Minya Initiative on the village level in other governorates. This new project that was implemented in sixteen governorates.

  8. Poisson Spot with Magnetic Levitation

    Science.gov (United States)

    Hoover, Matthew; Everhart, Michael; D'Arruda, Jose

    2010-01-01

    In this paper we describe a unique method for obtaining the famous Poisson spot without adding obstacles to the light path, which could interfere with the effect. A Poisson spot is the interference effect from parallel rays of light diffracting around a solid spherical object, creating a bright spot in the center of the shadow.

  9. Seagrass leaf element content

    NARCIS (Netherlands)

    Vonk, J.A.; Smulders, Fee O.H.; Christianen, Marjolijn J.A.; Govers, Laura L.

    2017-01-01

    Knowledge on the role of seagrass leaf elements and in particular micronutrients and their ranges is limited. We present a global database, consisting of 1126 unique leaf values for ten elements, obtained from literature and unpublished data, spanning 25 different seagrass species from 28 countries.

  10. On the Spot: Oceans

    OpenAIRE

    Male, Alan; Butterfield, Moira

    2000-01-01

    This a children's non-fiction, knowledge bearing picture book that is part of a Reader's Digest series called 'On the Spot'. The series deals with a range of topics related to the natural world and this one introduces its young audience to the ecosystems of the oceans. \\ud The publication was illustrated and designed by the author (Alan Male) and is technically described as a board book with interactive 'pop up' features, specifically conceived to engage children's discovery and learning thro...

  11. El spot electoral negativo

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez

    2011-01-01

    Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

  12. Utilization of chitinolytic bacterial isolates to control anthracnose of ...

    African Journals Online (AJOL)

    Colletotrichum spp. are causal agents of anthracnose in many plant species. Biological control of Colletotrichum spp. utilizing bacterial isolates and fungi has been reported. However, chitinolytic bacterial isolate utilization to control anthracnose of cocoa leaf has not seemingly been studied yet. In this study, we used ...

  13. Bacterial prostatitis.

    Science.gov (United States)

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  14. Antimicrobial activity of medicinal plant leaf extracts against pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Atikya Farjana

    2014-09-01

    Full Text Available Objective: To determine antibacterial activity of water, oil and methanol extracts of guava (Psidium guajava, green tea (Camellia sinensis, neem (Azadirachta indica and marigold (Calendula officinalis against different species of bacteria, Pseudomonas spp., Vibrio cholerae, Vibrio parahaemolyticus (V. parahaemolyticus, Klebsiella spp., Escherichia coli, Salmonella spp. and Staphylococcus aureus (S. aureus. Methods: Antibacterial activity of plant extracts was measured by agar well diffusion method. Results: Boiled water extracts of guava leaf showed the largest zone of inhibition (22 mm against V. parahaemolyticus. Water extracts of green tea leaf at boiling and room temperature showed 17.5 mm and 19 mm zone of inhibitions against V. parahaemolyticus and S. aureus, respectively. Boiled water extract of neem leaf showed moderate zone of inhibition against Escherichia coli (10 mm and Klebsiella spp. (11 mm. Water and oil extracts of marigold leaf at both boiling and room temperature did not show any zone of inhibition against any of the tested microorganisms. Methanol extracts of both guava and green tea leaves showed same zone of inhibition against Pseudomonus spp. (18 mm. Methanol extract of neem leaf showed antibacterial acitivity against Klebsiella spp. (16 mm and Vibrio cholerae (14 mm and that of marigold leaf showed antimicrobial activity against S. aureus (18 mm and Klebsiella spp. (12 mm. Conclusions: The results from the study suggest that the leaves of guava, green tea, neem and marigold show anibacterial activity against different bacterial species. They could be used as alternatives to common antimicrobial agents for treatment of bacterial infections.

  15. identification of common bean genotypes with dual leaf and pod ...

    African Journals Online (AJOL)

    ACSS

    2018-02-08

    Feb 8, 2018 ... IDENTIFICATION OF COMMON BEAN GENOTYPES WITH DUAL LEAF AND. POD RESISTANCE TO COMMON BACTERIAL BLIGHT DISEASE IN UGANDA. B.M.E. ALLADASSI, S.T. NKALUBO1, C. MUKANKUSI2, H.N. KAYAGA, P. GIBSON, R. EDEMA,. C.A. URREA3, J.D. KELLY4 and P.R. RUBAIHAYO.

  16. The development of a dense SNP-based consensus map and QTL detection for black spot resistance in five diploid rose populations [abstract

    Science.gov (United States)

    Black spot (BS) disease (Diplocarpon rosae (Lib.) Wolf) of rose is the most important leaf disease of garden roses in warm humid areas. Although the partial (horizontal) resistance to black spot has been shown to be moderately heritable, the responsible quantitative trait loci (QTL) remain unidentif...

  17. The Spotting Distribution of Wildfires

    Directory of Open Access Journals (Sweden)

    Jonathan Martin

    2016-06-01

    Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

  18. Transmission of tomato spotted wilt tospovirus by Thrips tabaci populations originating from leek

    NARCIS (Netherlands)

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

    1999-01-01

    The transmission of tomato spotted wilt tospovirus (TSWV) by Thrips tabaci collected from leek was studied using the petunia local-lesion leaf-disc assay. After an acquisition-access period of 72 h given to newborn larvae up to 8 h old, the efficiency of transmission by adults was determined in

  19. Emerging hot spot analysis

    DEFF Research Database (Denmark)

    Reinau, Kristian Hegner

    Traditionally, focus in the transport field, both politically and scientifically, has been on private cars and public transport. Freight transport has been a neglected topic. Recent years has seen an increased focus upon congestion as a core issue across Europe, resulting in a great need for know...... speed data for freight. Secondly, the analytical methods used, space-time cubes and emerging hot spot analysis, are also new in the freight transport field. The analysis thus estimates precisely how fast freight moves on the roads in Northern Jutland and how this has evolved over time....

  20. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  1. characterisation of bacterial brown spot pathogen from dry bean

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Biolog GN Microplates were used to assess carbon substrate utilisation. The SyrB gene was .... Positive reaction was observed as granular ... nutrient broth as positive control (Ignjatov et al.,. 2007). ..... nucleation-active Pseudomonas syringae.

  2. Characterisation of bacterial brown spot pathogen from dry bean ...

    African Journals Online (AJOL)

    African Crop Science Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 4 (2011) >. Log in or Register to get access to full text downloads.

  3. Geometric leaf placement strategies

    International Nuclear Information System (INIS)

    Fenwick, J D; Temple, S W P; Clements, R W; Lawrence, G P; Mayles, H M O; Mayles, W P M

    2004-01-01

    Geometric leaf placement strategies for multileaf collimators (MLCs) typically involve the expansion of the beam's-eye-view contour of a target by a uniform MLC margin, followed by movement of the leaves until some point on each leaf end touches the expanded contour. Film-based dose-distribution measurements have been made to determine appropriate MLC margins-characterized through an index d 90 -for multileaves set using one particular strategy to straight lines lying at various angles to the direction of leaf travel. Simple trigonometric relationships exist between different geometric leaf placement strategies and are used to generalize the results of the film work into d 90 values for several different strategies. Measured d 90 values vary both with angle and leaf placement strategy. A model has been derived that explains and describes quite well the observed variations of d 90 with angle. The d 90 angular variations of the strategies studied differ substantially, and geometric and dosimetric reasoning suggests that the best strategy is the one with the least angular variation. Using this criterion, the best straightforwardly implementable strategy studied is a 'touch circle' approach for which semicircles are imagined to be inscribed within leaf ends, the leaves being moved until the semicircles just touch the expanded target outline

  4. Final report on the safety assessment of AloeAndongensis Extract, Aloe Andongensis Leaf Juice,aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice,aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract.

    Science.gov (United States)

    2007-01-01

    Plant materials derived from the Aloe plant are used as cosmetic ingredients, including Aloe Andongensis Extract, Aloe Andongensis Leaf Juice, Aloe Arborescens Leaf Extract, Aloe Arborescens Leaf Juice, Aloe Arborescens Leaf Protoplasts, Aloe Barbadensis Flower Extract, Aloe Barbadensis Leaf, Aloe Barbadensis Leaf Extract, Aloe Barbadensis Leaf Juice, Aloe Barbadensis Leaf Polysaccharides, Aloe Barbadensis Leaf Water, Aloe Ferox Leaf Extract, Aloe Ferox Leaf Juice, and Aloe Ferox Leaf Juice Extract. These ingredients function primarily as skin-conditioning agents and are included in cosmetics only at low concentrations. The Aloe leaf consists of the pericyclic cells, found just below the plant's skin, and the inner central area of the leaf, i.e., the gel, which is used for cosmetic products. The pericyclic cells produce a bitter, yellow latex containing a number of anthraquinones, phototoxic compounds that are also gastrointestinal irritants responsible for cathartic effects. The gel contains polysaccharides, which can be acetylated, partially acetylated, or not acetylated. An industry established limit for anthraquinones in aloe-derived material for nonmedicinal use is 50 ppm or lower. Aloe-derived ingredients are used in a wide variety of cosmetic product types at concentrations of raw material that are 0.1% or less, although can be as high as 20%. The concentration of Aloe in the raw material also may vary from 100% to a low of 0.0005%. Oral administration of various anthraquinone components results in a rise in their blood concentrations, wide systemic distribution, accumulation in the liver and kidneys, and excretion in urine and feces; polysaccharide components are distributed systemically and metabolized into smaller molecules. aloe-derived material has fungicidal, antimicrobial, and antiviral activities, and has been effective in wound healing and infection treatment in animals. Aloe barbadensis (also known as Aloe vera)-derived ingredients were not toxic

  5. Two Volatile Organic Compounds Trigger Plant Self-Defense against a Bacterial Pathogen and a Sucking Insect in Cucumber under Open Field Conditions

    Directory of Open Access Journals (Sweden)

    Choong-Min Ryu

    2013-05-01

    Full Text Available Systemic acquired resistance (SAR is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields.

  6. Models of spots and flares

    International Nuclear Information System (INIS)

    Mullan, D.J.

    1983-01-01

    Laboratory experiments in recent years have shown that there are many more ways to drive a plasma out of equilibrium than to preserve equilibrium. In that sense, it is perhaps easier to understand why flares should occur in a stellar atmosphere than why a long-lived feature such as a dark spot should persist. The author summarizes work on the equilibrium structure of cool spots in the sun and stars. Since spots involve complex interactions between convective flows and magnetic fields, he needs to refer to observations for help in identifying the dominant processes which should enter into the modelling. His summary therefore begins by discussing certain relevant properties of spots in the solar atmosphere. The next sections deal with the magnetic fields in spots, the stability of spots, spot cooling and missing flux. The author concludes that spots should be viewed not simply as cool areas, but rather as engines which do the work of converting the energy of convective flows into flare-compatible form. (Auth.)

  7. Black-spot poison ivy.

    Science.gov (United States)

    Schram, Sarah E; Willey, Andrea; Lee, Peter K; Bohjanen, Kimberly A; Warshaw, Erin M

    2008-01-01

    In black-spot poison ivy dermatitis, a black lacquerlike substance forms on the skin when poison ivy resin is exposed to air. Although the Toxicodendron group of plants is estimated to be the most common cause of allergic contact dermatitis in the United States, black-spot poison ivy dermatitis is relatively rare.

  8. Rocky Mountain spotted fever, Colombia.

    Science.gov (United States)

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

    2007-07-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

  9. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  10. BACTERIAL CONSORTIUM

    Directory of Open Access Journals (Sweden)

    Payel Sarkar

    2013-01-01

    Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

  11. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    , 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...... 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...

  12. Bacterial meningitis

    NARCIS (Netherlands)

    Heckenberg, Sebastiaan G. B.; Brouwer, Matthijs C.; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained,

  13. Bacterial lipases

    NARCIS (Netherlands)

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

    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,

  14. Bacterial stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  15. Studies on an X-ray induced crinkled leaf mutant of Trichosanthes anguina L

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Subodh Kumar

    1986-06-01

    Crinkled leaf mutant isolated in the second generation after treatment with X-ray bred true in subsequent generation. The mutant was a late flowering type with increased percentage of PMC's with chromosomal abnormality and pollen grain sterility. TLC study on phenolic compounds in leaves showed that both the mother line and the mutant had equal number of spots but they differed from each other with respect to four spots. Spot Nos. 2 and 4 of the mother line were absent in the mutant but the latter had two new spots (spot Nos. 11 and 12). The mutant and the mother line also differed from each other in pollen grain morohology. 3 figures, 2 tables, 4 refs.

  16. Identification of Alfalfa Leaf Diseases Using Image Recognition Technology.

    Directory of Open Access Journals (Sweden)

    Feng Qin

    Full Text Available Common leaf spot (caused by Pseudopeziza medicaginis, rust (caused by Uromyces striatus, Leptosphaerulina leaf spot (caused by Leptosphaerulina briosiana and Cercospora leaf spot (caused by Cercospora medicaginis are the four common types of alfalfa leaf diseases. Timely and accurate diagnoses of these diseases are critical for disease management, alfalfa quality control and the healthy development of the alfalfa industry. In this study, the identification and diagnosis of the four types of alfalfa leaf diseases were investigated using pattern recognition algorithms based on image-processing technology. A sub-image with one or multiple typical lesions was obtained by artificial cutting from each acquired digital disease image. Then the sub-images were segmented using twelve lesion segmentation methods integrated with clustering algorithms (including K_means clustering, fuzzy C-means clustering and K_median clustering and supervised classification algorithms (including logistic regression analysis, Naive Bayes algorithm, classification and regression tree, and linear discriminant analysis. After a comprehensive comparison, the segmentation method integrating the K_median clustering algorithm and linear discriminant analysis was chosen to obtain lesion images. After the lesion segmentation using this method, a total of 129 texture, color and shape features were extracted from the lesion images. Based on the features selected using three methods (ReliefF, 1R and correlation-based feature selection, disease recognition models were built using three supervised learning methods, including the random forest, support vector machine (SVM and K-nearest neighbor methods. A comparison of the recognition results of the models was conducted. The results showed that when the ReliefF method was used for feature selection, the SVM model built with the most important 45 features (selected from a total of 129 features was the optimal model. For this SVM model, the

  17. Identification of Alfalfa Leaf Diseases Using Image Recognition Technology

    Science.gov (United States)

    Qin, Feng; Liu, Dongxia; Sun, Bingda; Ruan, Liu; Ma, Zhanhong; Wang, Haiguang

    2016-01-01

    Common leaf spot (caused by Pseudopeziza medicaginis), rust (caused by Uromyces striatus), Leptosphaerulina leaf spot (caused by Leptosphaerulina briosiana) and Cercospora leaf spot (caused by Cercospora medicaginis) are the four common types of alfalfa leaf diseases. Timely and accurate diagnoses of these diseases are critical for disease management, alfalfa quality control and the healthy development of the alfalfa industry. In this study, the identification and diagnosis of the four types of alfalfa leaf diseases were investigated using pattern recognition algorithms based on image-processing technology. A sub-image with one or multiple typical lesions was obtained by artificial cutting from each acquired digital disease image. Then the sub-images were segmented using twelve lesion segmentation methods integrated with clustering algorithms (including K_means clustering, fuzzy C-means clustering and K_median clustering) and supervised classification algorithms (including logistic regression analysis, Naive Bayes algorithm, classification and regression tree, and linear discriminant analysis). After a comprehensive comparison, the segmentation method integrating the K_median clustering algorithm and linear discriminant analysis was chosen to obtain lesion images. After the lesion segmentation using this method, a total of 129 texture, color and shape features were extracted from the lesion images. Based on the features selected using three methods (ReliefF, 1R and correlation-based feature selection), disease recognition models were built using three supervised learning methods, including the random forest, support vector machine (SVM) and K-nearest neighbor methods. A comparison of the recognition results of the models was conducted. The results showed that when the ReliefF method was used for feature selection, the SVM model built with the most important 45 features (selected from a total of 129 features) was the optimal model. For this SVM model, the

  18. Production of polyclonal antiserum specific to the 27.5 kDa envelope protein of white spot syndrome virus

    NARCIS (Netherlands)

    You, Z.O.; Nadala, E.C.B.; Yang, J.S.; Hulten, van M.C.W.; Loh, P.C.

    2002-01-01

    A truncated version of the white spot syndrome virus (WSSV) 27.5 kDa envelope protein was expressed as a histidine tag fusion protein in Escherichia coli. The bacterial expression system allowed the production of up to 10 mg of purified recombinant protein per liter of bacterial culture. Antiserum

  19. Spotting psychopaths using technology.

    Science.gov (United States)

    Hulbert, Sarah; Adeli, Hojjat

    2015-01-01

    For the past three and a half decades, the Psychopathy Checklist-Revised (PCL-R) and the self-report Psychopathic Personality Inventory-Revised (PPI-R) have been the standard measures for the diagnosis of psychopathy. Technological approaches can enhance these diagnostic methodologies. The purpose of this paper is to present a state-of-the-art review of various technological approaches for spotting psychopathy, such as electroencephalogram (EEG), magnetic resonance imaging (MRI), functional MRI (fMRI), transcranial magnetic stimulation (TMS), and other measures. Results of EEG event-related potential (ERP) experiments support the theory that impaired amygdala function may be responsible for abnormal fear processing in psychopathy, which can ultimately manifest as psychopathic traits, as outlined by the PCL-R or PPI-R. Imaging studies, in general, point to reduced fear processing capabilities in psychopathic individuals. While the human element, introduced through researcher/participant interactions, can be argued as unequivocally necessary for diagnosis, these purely objective technological approaches have proven to be useful in conjunction with the subjective interviewing and questionnaire methods for differentiating psychopaths from non-psychopaths. Furthermore, these technologies are more robust than behavioral measures, which have been shown to fail.

  20. Effect of inorganic nutrients on relative contributions of fungi and bacteria to carbon flow from submerged decomposing leaf litter

    Science.gov (United States)

    Vladislav Gulis; Keller Suberkropp

    2003-01-01

    The relative contributions of fungi and bacteria to carbon flow from submerged decaying plant litter at different levels of inorganic nutrients (N and P) were studied. We estimated leaf mass loss, fungal and bacterial biomass and production, and microbial respiration and constructed partial carbon budgets for red maple leaf disks precolonized in a stream and then...

  1. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  2. Stomatal conductance, canopy temperature, and leaf area index estimation using remote sensing and OBIA techniques

    Science.gov (United States)

    S. Panda; D.M. Amatya; G. Hoogenboom

    2014-01-01

    Remotely sensed images including LANDSAT, SPOT, NAIP orthoimagery, and LiDAR and relevant processing tools can be used to predict plant stomatal conductance (gs), leaf area index (LAI), and canopy temperature, vegetation density, albedo, and soil moisture using vegetation indices like normalized difference vegetation index (NDVI) or soil adjusted...

  3. Root bacterial endophytes alter plant phenotype, but not physiology

    DEFF Research Database (Denmark)

    Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.

    2016-01-01

    (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light-Asat, and saturating CO2-Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf...... growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did......Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from the Populus root microbiome, influenced plant...

  4. Leaf-IT: An Android application for measuring leaf area.

    Science.gov (United States)

    Schrader, Julian; Pillar, Giso; Kreft, Holger

    2017-11-01

    The use of plant functional traits has become increasingly popular in ecological studies because plant functional traits help to understand key ecological processes in plant species and communities. This also includes changes in diversity, inter- and intraspecific interactions, and relationships of species at different spatiotemporal scales. Leaf traits are among the most important traits as they describe key dimensions of a plant's life history strategy. Further, leaf area is a key parameter with relevance for other traits such as specific leaf area, which in turn correlates with leaf chemical composition, photosynthetic rate, leaf longevity, and carbon investment. Measuring leaf area usually involves the use of scanners and commercial software and can be difficult under field conditions. We present Leaf-IT, a new smartphone application for measuring leaf area and other trait-related areas. Leaf-IT is free, designed for scientific purposes, and runs on Android 4 or higher. We tested the precision and accuracy using objects with standardized area and compared the area measurements of real leaves with the well-established, commercial software WinFOLIA using the Altman-Bland method. Area measurements of standardized objects show that Leaf-IT measures area with high accuracy and precision. Area measurements with Leaf-IT of real leaves are comparable to those of WinFOLIA. Leaf-IT is an easy-to-use application running on a wide range of smartphones. That increases the portability and use of Leaf-IT and makes it possible to measure leaf area under field conditions typical for remote locations. Its high accuracy and precision are similar to WinFOLIA. Currently, its main limitation is margin detection of damaged leaves or complex leaf morphologies.

  5. Diverse mechanisms of plant resistance to cauliflower mosaic virus revealed by leaf skeleton hybridization.

    Science.gov (United States)

    Melcher, U; Brannan, C M; Gardner, C O; Essenberg, R C

    1992-01-01

    Plants not hosts for cauliflower mosaic virus (CaMV) may prevent systemic CaMV infection by interfering with dissemination of infection through the plant or by preventing viral replication and maturation. Leaf skeleton hybridization allows distinction between these two barriers. The technique assesses the spatial distribution of CaMV in an inoculated leaf by hybridization of a skeleton of the leaf with a CaMV DNA probe. Leaves or leaflets of soybean, cucumber, peanut, tomato, lettuce, spinach, pepper, onion, wheat, maize and barley, inoculated with CaMV DNA or CaMV virions were processed for leaf skeleton hybridization either immediately after inoculation or two weeks thereafter. Autoradiographic images of soybean and cucumber skeletons had many dark spots suggesting that CaMV DNA replication and local spread had occurred. Images of onion leaf skeletons prepared two weeks after inoculation with CaMV DNA had fewer spots. To test whether these spots resulted from CaMV replication, DNA was extracted from inoculated onion leaves and analyzed by electrophoresis, blotting and hybridization. Molecules recovered two weeks after inoculation resembled those inoculated, indicating absence of replication. For the other species, we found no evidence of local spread of CaMV infections. Thus, many plant species resist systemic CaMV infection by preventing replication or local spread of CaMV, while others solely prevent systemic movement of infection.

  6. Mutant of Japanese pear resistant to Black Spot Disease

    International Nuclear Information System (INIS)

    Sanada, T.; Nishida, T.; Ikeda, F.

    1987-01-01

    Full text: Nijisseike is one of the leading cultivars of Japanese pear (Pyrus serotinea Rehd.), but susceptible to black spot disease. Farmers try to prevent this disease by wrapping the fruit with a paper bag and by repeated spraying of fungicides. The disease is caused by a Japanese pear pathotype of Alternaria alternata (Fr.) Keissler. Susceptibility is controlled by a single dominant gene. In 1962, grafted trees of this cultivar were planted at a distance between 53 and 93 m from the 60 Co source in the gamma-field (daily dose 15-4 rad). One branch on a tree planted at 53 m was detected as resistant in 1981. Under field conditions, black spots were observed on many fruits and leaves of the original trees by natural infection in early July, however, they were not observed on the mutant. To examine the resistance of the mutant, artificial inoculations were made using spores of the pathogen and the host specific toxin produced by germinating spores. When some drops of the spore suspension are placed on leaves, the formation of black spots depends upon the leaf age. In a resistant cv. as Chojuro, black spot symptoms are formed only when inoculated on young leaves. An intermediate reaction was observed in the mutant, whereas the original Nijisseiki showed severe symptoms. When inoculation was made on matured fruit skins, no black spot was formed on the mutant just like on the resistant cv. Chojuro, while many small black spots were formed and grew into large spots overlapping each other on the susceptible cv. Nijisseiki. In case of the crude toxin inoculation (4-0.04 ppm) of cv. Nijisseiki black spots were formed on the surface of the susceptible fruit skin, and necrotic lesions at the cut end of detached small pieces of leaves, although reaction on fruit skins was weaker compared with inoculation by spores. However, no symptoms were observed from the toxin application on the mutant and the resistant cv. Chojuro. That the resistance of the mutant is classified as

  7. [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. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  8. Separation and identification of Musa acuminate Colla (banana) leaf proteins by two-dimensional gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Lu, Y; Qi, Y X; Zhang, H; Zhang, H Q; Pu, J J; Xie, Y X

    2013-12-19

    To establish a proteomic reference map of Musa acuminate Colla (banana) leaf, we separated and identified leaf proteins using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS). Tryptic digests of 44 spots were subjected to peptide mass fingerprinting (PMF) by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS. Three spots that were not identified by MALDI-TOF MS analysis were identified by searching against the NCBInr, SwissProt, and expressed sequence tag (EST) databases. We identified 41 unique proteins. The majority of the identified leaf proteins were found to be involved in energy metabolism. The results indicate that 2D-PAGE is a sensitive and powerful technique for the separation and identification of Musa leaf proteins. A summary of the identified proteins and their putative functions is discussed.

  9. Numerical optimisation in spot detector design

    NARCIS (Netherlands)

    van der Heijden, Ferdinand; Apperloo, W.; Spreeuwers, Lieuwe Jan

    1997-01-01

    Spots are image details resulting from objects, the projections of which are so small that the inner structure of these objects cannot be resolved from their image. Spot detectors are image operators aiming at the detection and localisation of spots in the image. Most spot detectors can be tuned

  10. Managing emerging threats to spotted owls

    Science.gov (United States)

    Ho Yi Wan; Joseph L. Ganey; Christina D. Vojta; Samuel A. Cushman

    2018-01-01

    The 3 spotted owl (Strix occidentalis) subspecies in North America (i.e., northern spotted owl [S. o. caurina], California spotted owl [S. o. occidentalis], Mexican spotted owl [S. o. lucida]) have all experienced population declines over the past century due to habitat loss and fragmentation from logging. Now, the emerging influences of climate change, high-severity...

  11. 9 CFR 149.4 - Spot audit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

  12. Magnitude of genotype x environment interaction for bacterial leaf ...

    African Journals Online (AJOL)

    African Crop Science Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 24, No 1 (2016) >. Log in or Register to get access to full text downloads.

  13. magnitude of genotype x environment interaction for bacterial leaf

    African Journals Online (AJOL)

    ACSS

    African Crop Science Journal, Vol. ... effects of treatments into genotype, environment, and genotype x environment (G x E) interactions. Results .... method is economically effective (Niño-Liu et al., ..... This phenomenon indicated differences in.

  14. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  15. Bacterial mitosis

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...

  16. Leaf absorbance and photosynthesis

    Science.gov (United States)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  17. Characterization of a new pathovar of Agrobacterium vitis causing banana leaf blight in China.

    Science.gov (United States)

    Huang, Siliang; Long, Mengling; Fu, Gang; Lin, Shanhai; Qin, Liping; Hu, Chunjin; Cen, Zhenlu; Lu, Jie; Li, Qiqin

    2015-01-01

    A new banana leaf blight was found in Nanning city, China, during a 7-year survey (2003-2009) of the bacterial diseases on banana plants. Eight bacterial strains were isolated from affected banana leaves, and identified as an intraspecific taxon of Agrobacterium vitis based on their 16S rDNA sequence similarities with those of 37 randomly selected bacterial strains registered in GenBank database. The representative strain Ag-1 was virulent on banana leaves and shared similar growth and biochemical reactions with the reference strain IAM14140 of A. vitis. The strains causing banana leaf blight were denominated as A. vitis pv. musae. The traditional A. vitis strains virulent to grapevines were proposed to be revised as A. vitis pv. vitis. This is the first record of a new type of A. vitis causing banana leaf blight in China. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Remote sensing based mapping of leaf nitrogen and leaf area index in European landscapes using the REGularized canopy reFLECtance (REGFLEC) model

    DEFF Research Database (Denmark)

    Boegh, E.; Houborg, R.; Bienkowski, J.

    2011-01-01

    index (LAI) are important determinants of the maximum CO2 Methods/Approach uptake by plants and trees. In the EU project NitroEurope, high spatial resolution (10-20 m) remote sensing data from the HRG and HRVIR sensors onboard the SPOT satellites were acquired to derive maps of leaf N and LAI for 5...... European landscapes. The estimations of leaf N, Cab and LAI soil reflectance parameters and canopy parameters are discussed in relation to the prevailing soil types and vegetation characteristics of land cover classes across the 5 European landscapes....

  19. NOVEL ASPECTS OF SPOTTED WING DROSOPHILA BIOLOGY AND IMPROVED METHODS OF REARING

    Science.gov (United States)

    Drosophila suzukii (Mats.) or the spotted wing Drosophila (SWD), is a global pest of soft fruits that can now be reared on a standard Drosophila diet containing the fly's own natural food: soft-skinned berries. The techniques tested here can thwart bacterial and fungal disease that can destroy more ...

  20. Poisson's spot and Gouy phase

    Science.gov (United States)

    da Paz, I. G.; Soldati, Rodolfo; Cabral, L. A.; de Oliveira, J. G. G.; Sampaio, Marcos

    2016-12-01

    Recently there have been experimental results on Poisson spot matter-wave interferometry followed by theoretical models describing the relative importance of the wave and particle behaviors for the phenomenon. We propose an analytical theoretical model for Poisson's spot with matter waves based on the Babinet principle, in which we use the results for free propagation and single-slit diffraction. We take into account effects of loss of coherence and finite detection area using the propagator for a quantum particle interacting with an environment. We observe that the matter-wave Gouy phase plays a role in the existence of the central peak and thus corroborates the predominantly wavelike character of the Poisson's spot. Our model shows remarkable agreement with the experimental data for deuterium (D2) molecules.

  1. Pseudomonas floridensis sp. nov., a bacterial pathogen isolated from tomato.

    Science.gov (United States)

    Timilsina, Sujan; Minsavage, Gerald V; Preston, James; Newberry, Eric A; Paret, Matthews L; Goss, Erica M; Jones, Jeffrey B; Vallad, Gary E

    2018-01-01

    An unusual fluorescent pseudomonad was isolated from tomato exhibiting leaf spot symptoms similar to bacterial speck. Strains were fluorescent, oxidase- and arginine-dihydrolase-negative, elicited a hypersensitive reaction on tobacco and produced a soft rot on potato slices. However, the strains produced an unusual yellow, mucoid growth on media containing 5 % sucrose that is not typical of levan. Based on multilocus sequence analysis using 16S rRNA, gap1, gltA, gyrB and rpoD, these strains formed a distinct phylogenetic group in the genus Pseudomonas and were most closely related to Pseudomonas viridiflava within the Pseudomonassyringae complex. Whole-genome comparisons, using average nucleotide identity based on blast, of representative strain GEV388 T and publicly available genomes representing the genus Pseudomonas revealed phylogroup 7 P. viridiflava strain UASW0038 and P. viridiflava type strain ICMP 2848 T as the closest relatives with 86.59 and 86.56 % nucleotide identity, respectively. In silico DNA-DNA hybridization using the genome-to-genome distance calculation method estimated 31.1 % DNA relatedness between GEV388 T and P. viridiflava ATCC 13223 T , strongly suggesting the strains are representatives of different species. These results together with Biolog GEN III tests, fatty acid methyl ester profiles and phylogenetic analysis using 16S rRNA and multiple housekeeping gene sequences demonstrated that this group represents a novel species member of the genus Pseudomonas. The name Pseudomonas floridensis sp. nov. is proposed with GEV388 T (=LMG 30013 T =ATCC TSD-90 T ) as the type strain.

  2. Laser based spot weld characterization

    Science.gov (United States)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  3. The genetic variance of resistance in M3 lines of rice against leaf blight disease

    International Nuclear Information System (INIS)

    Mugiono

    1979-01-01

    Seeds of Pelita I/1 rice variety were irradiated with 20, 30, 40 and 50 krad of gamma rays from a 60 Co source. Plants of M 3 lines were inoculated with bacterial leaf blight, Xanthomonas oryzae (Uzeda and Ishiyama) Downson, using clipping method. The coefficient of genetic variability of resistance against leaf blight disease increased with increasing dose. Highly significant difference in the genetic variance of resistance were found between the treated samples and the control. Dose of 20 krad gave good probability for selection of plants resistant against leaf blight disease. (author)

  4. Is this Red Spot the Blue Spot (locus ceruleum)?

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2010-06-15

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  5. Is this Red Spot the Blue Spot (locus ceruleum)?

    International Nuclear Information System (INIS)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon

    2010-01-01

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  6. Statistical hot spot analysis of reactor cores

    International Nuclear Information System (INIS)

    Schaefer, H.

    1974-05-01

    This report is an introduction into statistical hot spot analysis. After the definition of the term 'hot spot' a statistical analysis is outlined. The mathematical method is presented, especially the formula concerning the probability of no hot spots in a reactor core is evaluated. A discussion with the boundary conditions of a statistical hot spot analysis is given (technological limits, nominal situation, uncertainties). The application of the hot spot analysis to the linear power of pellets and the temperature rise in cooling channels is demonstrated with respect to the test zone of KNK II. Basic values, such as probability of no hot spots, hot spot potential, expected hot spot diagram and cumulative distribution function of hot spots, are discussed. It is shown, that the risk of hot channels can be dispersed equally over all subassemblies by an adequate choice of the nominal temperature distribution in the core

  7. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    compounds these must first be undergo extracellular hydrolysis. Bacteria have a great diversity with respect to types of metabolism that far exceeds the metabolic repertoire of eukaryotic organisms. Bacteria play a fundamental role in the biosphere and certain key processes such as, for example......, the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  8. Bacterial Actins.

    Science.gov (United States)

    Izoré, Thierry; van den Ent, Fusinita

    2017-01-01

    A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.

  9. Rocky Mountain spotted fever, Panama.

    Science.gov (United States)

    Estripeaut, Dora; Aramburú, María Gabriela; Sáez-Llorens, Xavier; Thompson, Herbert A; Dasch, Gregory A; Paddock, Christopher D; Zaki, Sherif; Eremeeva, Marina E

    2007-11-01

    We describe a fatal pediatric case of Rocky Mountain spotted fever in Panama, the first, to our knowledge, since the 1950s. Diagnosis was established by immunohistochemistry, PCR, and isolation of Rickettsia rickettsii from postmortem tissues. Molecular typing demonstrated strong relatedness of the isolate to strains of R. rickettsii from Central and South America.

  10. Identification of an emergent bacterial blight of garlic in Brazil

    Science.gov (United States)

    Outbreaks of a bacterial blight disease occurred on garlic (Allium sativum) cultivars Roxo Caxiense, Quiteria and Cacador in Southern Brazil, and threatened the main production regions of Rio Grande do Sul State. Symptoms were characterized by watersoaked reddish streaks along the leaf midrib, follo...

  11. Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition.

    Science.gov (United States)

    Poosakkannu, Anbu; Nissinen, Riitta; Kytöviita, Minna-Maarit

    2017-11-01

    The effects of arbuscular mycorrhizal (AM) fungi on plant-associated microbes are poorly known. We tested the hypothesis that colonization by an AM fungus affects microbial species richness and microbial community composition of host plant tissues. We grew the grass, Deschampsia flexuosa in a greenhouse with or without the native AM fungus, Claroideoglomus etunicatum. We divided clonally produced tillers into two parts: one inoculated with AM fungus spores and one without AM fungus inoculation (non-mycorrhizal, NM). We characterized bacterial (16S rRNA gene) and fungal communities (internal transcribed spacer region) in surface-sterilized leaf and root plant compartments. AM fungus inoculation did not affect microbial species richness or diversity indices in leaves or roots, but the AM fungus inoculation significantly affected bacterial community composition in leaves. A total of three OTUs in leaves belonging to the phylum Firmicutes positively responded to the presence of the AM fungus in roots. Another six OTUs belonging to the Proteobacteria (Alpha, Beta, and Gamma) and Bacteroidetes were significantly more abundant in NM plants when compared to AM fungus-inoculated plants. Further, there was a significant correlation between plant dry weight and leaf microbial community compositional shift. Also, there was a significant correlation between leaf bacterial community compositional shift and foliar nitrogen content changes due to AM fungus inoculation. The results suggest that AM fungus colonization in roots has a profound effect on plant physiology that is reflected in leaf bacterial community composition.

  12. Biodiversity hot spot on a hot spot: novel extremophile diversity in Hawaiian fumaroles.

    Science.gov (United States)

    Wall, Kate; Cornell, Jennifer; Bizzoco, Richard W; Kelley, Scott T

    2015-01-06

    Fumaroles (steam vents) are the most common, yet least understood, microbial habitat in terrestrial geothermal settings. Long believed too extreme for life, recent advances in sample collection and DNA extraction methods have found that fumarole deposits and subsurface waters harbor a considerable diversity of viable microbes. In this study, we applied culture-independent molecular methods to explore fumarole deposit microbial assemblages in 15 different fumaroles in four geographic locations on the Big Island of Hawai'i. Just over half of the vents yielded sufficient high-quality DNA for the construction of 16S ribosomal RNA gene sequence clone libraries. The bacterial clone libraries contained sequences belonging to 11 recognized bacterial divisions and seven other division-level phylogenetic groups. Archaeal sequences were less numerous, but similarly diverse. The taxonomic composition among fumarole deposits was highly heterogeneous. Phylogenetic analysis found cloned fumarole sequences were related to microbes identified from a broad array of globally distributed ecotypes, including hot springs, terrestrial soils, and industrial waste sites. Our results suggest that fumarole deposits function as an "extremophile collector" and may be a hot spot of novel extremophile biodiversity. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  13. (TECTONA GRANDIS LEAF POWDER

    Directory of Open Access Journals (Sweden)

    Yash Mishra

    2015-01-01

    Full Text Available In this study, the adsorption potential of Teak (Tectona grandis leaf powder (TLP toremove Methylene blue (MB and Malachite Green (MG dye molecules from aqueoussolution was investigated. Batch experiments were conducted to evaluate the influenceof operational parameters such as, pH (2−9, adsorbent dosage (1−7 g/L, contact time(15−150 minutes and initial dye concentration (20−120 mg/L at stirring speed of 150rpm for the adsorption of MB and MG on TLP. Maximum removal efficiency of 98.4%and 95.1% was achieved for MB and MG dye, respectively. The experimentalequilibrium data were analysed using Langmuir, Freundlich and Temkin isothermmodels and it was found that, it fitted well to the Freundlich isotherm model. Thesurface structure and morphology of the adsorbent was characterized using scanningelectron microscopy (SEM and the presence of functional groups and its interactionwith the dye molecules were analysed using Fourier transform infrared spectroscopy(FTIR. Based on the investigation, it has been demonstrated that the teak leaf powderhas good potential for effective adsorption of methylene blue and malachite green dye.

  14. Exclusion of EDNRB and KIT as the basis for white spotting in Border Collies.

    Science.gov (United States)

    Metallinos, D; Rine, J

    2000-01-01

    White spotting patterns in mammals can be caused by mutations in the genes for the endothelin B receptor and c-Kit, whose protein products are necessary for proper migration, differentiation or survival of the melanoblast population of cells. Although there are many different dog breeds that segregate white spotting patterns, no genes have been identified that are linked to these phenotypes. An intercross was generated from a female Newfoundland and a male Border Collie and the white spotting phenotypes of the intercross progeny were evaluated by measuring percentage surface area of white in the puppies. The Border Collie markings segregated as a simple autosomal recessive (7/25 intercross progeny had the phenotype). Two candidate genes, for the endothelin B receptor (EDNRB) and c-Kit (KIT), were evaluated for segregation with the white spotting pattern. Polymorphisms between the Border Collie and Newfoundland were identified for EDNRB using Southern analysis after a portion of the canine gene had been cloned. Polymorphisms for KIT were identified using a microsatellite developed from a bacterial artificial chromosome containing the canine gene. Both EDNRB and KIT were excluded as a cause of the white spotting pattern in at least two of the intercross progeny. Although these genes have been implicated in white spotting in other mammals, including horses, pigs, cows, mice and rats, they do not appear to be responsible for the white spotting pattern found in the Border Collie breed of dog.

  15. Occurrence of Target Spot on Rosemary Caused by Corynespora cassiicola in Korea

    Directory of Open Access Journals (Sweden)

    Wang-Hyu Lee

    2013-03-01

    Full Text Available The purpose of this experiment was to investigate the development of new spot disease on the leaf and stem of rosemary (Rosmarinus officinalis in commercial greenhouses at Jeonju and Namwon in Korea. Incidence of target spot on rosemary was higher at the end of the rainy season with high humidity. Those symptoms were black ring spots (3−5 mm in diameter and withering on green leaves and stems. Conidiophores and conidia were formed on the infected tissue in moist chamber and conidia were shown as the cylindrical and oval types in chain, ranged from 55 to 275 μm in length, and 7 to 14 μm in width. Conidia with eight to ten pseudosepta were formed on the conidiapore. The optimum growth temperature of isolates was 30oC on the PDA medium under the dark condition. In the pathogenesis test, the target spot and withering symptoms were appeared on the leaves and stems 3 days after inoculation showing similar symptoms compared to those of in nature. The same fungus was re-isolated from infected lesion, indicating that Corynespora cassiicola caused leaf target spot and twig blight on rosemary. The rDNA ITS nucleotide sequences of the pure cultured isolate from the diseased area on rosemary showed 100% similarity to the sequences of C. cassiicola available in the GenBank database (JQ595296, JQ595297, FJ852715 and AY238606. Therefore, we report that the target spot of leaves and stems in rosemary was caused by C. cassiicola.

  16. The spot market and the spot price: applicability and limitations

    International Nuclear Information System (INIS)

    White, G. Jr.

    1987-01-01

    The subject of spot prices and their relationship to long-term contracting is addressed. The author is associated with Nuexco, which originally was called the Nuclear Exchange Corporation. They use the term Exchange Value which originated in the idea that Nuexco operated an exchange 'bank' - those with too much uranium could 'bank it', those with short-term needs could borrow from the 'bank'. If the borrower repaid slightly more or less the difference was settled using the 'exchange value'. This became used for longer-term transactions and now settling the monthly value is an important part of Nuexco's activities. The exact nature of the Exchange Value is defined. Now more and more buyers are insisting on spot market related pricing even where this is not meaningfully related to uranium production costs. (U.K.)

  17. Laser Pyrometer For Spot Temperature Measurements

    Science.gov (United States)

    Elleman, D. D.; Allen, J. L.; Lee, M. C.

    1988-01-01

    Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

  18. Laser Spot Detection Based on Reaction Diffusion

    OpenAIRE

    Alejandro Vázquez-Otero; Danila Khikhlukha; J. M. Solano-Altamirano; Raquel Dormido; Natividad Duro

    2016-01-01

    Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presente...

  19. Transcriptome reprogramming of resistant and susceptible peach genotypes during Xanthomonas arboricola pv. pruni early leaf infection.

    Directory of Open Access Journals (Sweden)

    Fabio Gervasi

    Full Text Available Bacterial spot caused by Xanthomonas arboricola pv. pruni (Xap is a major threat to Prunus species worldwide. The molecular mechanisms of peach resistance to Xap during early leaf infection were investigated by RNA-Seq analysis of two Prunus persica cultivars, 'Redkist' (resistant, and 'JH Hale' (susceptible at 30 minutes, 1 and 3 hours-post-infection (hpi. Both cultivars exhibited extensive modulation of gene expression at 30 mpi, which reduced significantly at 1 hpi, increasing again at 3 hpi. Overall, 714 differentially expressed genes (DEGs were detected in 'Redkist' (12% at 30 mpi and 1 hpi and 88% at 3 hpi. In 'JH Hale', 821 DEGs were identified (47% at 30 mpi and 1 hpi and 53% at 3 hpi. Highly up-regulated genes (fold change > 100 at 3 hpi exhibited higher fold change values in 'Redkist' than in 'JH Hale'. RNA-Seq bioinformatics analyses were validated by RT-qPCR. In both cultivars, DEGs included genes with putative roles in perception, signal transduction, secondary metabolism, and transcription regulation, and there were defense responses in both cultivars, with enrichment for the gene ontology terms, 'immune system process', 'defense response', and 'cell death'. There were particular differences between the cultivars in the intensity and kinetics of modulation of expression of genes with putative roles in transcriptional activity, secondary metabolism, photosynthesis, and receptor and signaling processes. Analysis of differential exon usage (DEU revealed that both cultivars initiated remodeling their transcriptomes at 30 mpi; however, 'Redkist' exhibited alternative exon usage for a greater number of genes at every time point compared with 'JH Hale'. Candidate resistance genes (WRKY-like, CRK-like, Copper amine oxidase-like, and TIR-NBS-LRR-like are of interest for further functional characterization with the aim of elucidating their role in Prunus spp. resistance to Xap.

  20. 7 CFR 1421.11 - Spot checks.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Spot checks. 1421.11 Section 1421.11 Agriculture... ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 General § 1421.11 Spot checks. (a) CCC... CCC access to the farm and storage facility as necessary to conduct collateral inspections, or “spot...

  1. 21 CFR 886.1435 - Maxwell spot.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Maxwell spot. 886.1435 Section 886.1435 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1435 Maxwell spot. (a) Identification. A Maxwell spot is an AC...

  2. Antimicrobial compounds from leaf extracts of Jatropha curcas, Psidium guajava, and Andrographis paniculata.

    Science.gov (United States)

    Rahman, M M; Ahmad, S H; Mohamed, M T M; Ab Rahman, M Z

    2014-01-01

    The present research was conducted to discover antimicrobial compounds in methanolic leaf extracts of Jatropha curcas and Andrographis paniculata and ethanolic leaf extract of Psidium guajava and the effectiveness against microbes on flower preservative solution of cut Mokara Red orchid flowers was evaluated. The leaves were analyzed using gas chromatography-mass spectrometry. A total of nine, 66, and 29 compounds were identified in J. curcas, P. guajava, and A. paniculata leaf extracts, with five (88.18%), four (34.66%), and three (50.47%) having unique antimicrobial compounds, respectively. The experimental design on vase life was conducted using a completely randomized design with 10 replications. The flower vase life was about 6 days in the solution containing the P. guajava and A. paniculata leaf extracts at 15 mg/L. Moreover, solution with leaf extracts of A. paniculata had the lowest bacterial count compared to P. guajava and J. curcas. Thus, these leaf extracts revealed the presence of relevant antimicrobial compounds. The leaf extracts have the potential as a cut flower solution to minimize microbial populations and extend flower vase life. However, the activities of specific antimicrobial compounds and double or triple combination leaf extracts to enhance the effectiveness to extend the vase life need to be tested.

  3. Spot på samtalen:

    DEFF Research Database (Denmark)

    Danneris, Sophie; Jensen, Tanja Dall; Caswell, Dorte

    Spot på samtalen sætter fokus på det, der konkret foregår i samtaler mellem borgere og de beskæftigelsesfaglige medarbejdere i jobcentrene. Da de udsatte grupper i mange tilfælde er langt fra arbejdsmarkedet, er interessen rettet mod, hvilke forhold i kontakten med beskæftigelsessystemet, der...... har betydning hvilke indsatser ledige modtager, men også hvordan de modtager dem. Her rettes blikket mod den centrale del af den beskæftigelsespolitiske indsats som samtalerne udgør. I Spot på samtalen er blikket rettet mod de dynamikker, mønstre og mekanismer, der kommer i spil i samtalerne i...

  4. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  5. Managing Rocky Mountain spotted fever.

    Science.gov (United States)

    Minniear, Timothy D; Buckingham, Steven C

    2009-11-01

    Rocky Mountain spotted fever is caused by the tick-borne bacterium Rickettsia rickettsii. Symptoms range from moderate illness to severe illness, including cardiovascular compromise, coma and death. The disease is prevalent in most of the USA, especially during warmer months. The trademark presentation is fever and rash with a history of tick bite, although tick exposure is unappreciated in over a third of cases. Other signature symptoms include headache and abdominal pain. The antibiotic therapy of choice for R. rickettsii infection is doxycycline. Preventive measures for Rocky Mountain spotted fever and other tick-borne diseases include: wearing long-sleeved, light colored clothing; checking for tick attachment and removing attached ticks promptly; applying topical insect repellent; and treating clothing with permethrin.

  6. Measurement of laser spot quality

    Science.gov (United States)

    Milster, T. D.; Treptau, J. P.

    1991-01-01

    Several ways of measuring spot quality are compared. We examine in detail various figures of merit such as full width at half maximum (FWHM), full width at 1/(e exp 2) maximum, Strehl ratio, and encircled energy. Our application is optical data storage, but results can be applied to other areas like space communications and high energy lasers. We found that the optimum figure of merit in many cases is Strehl ratio.

  7. Sweet Spots and Door Stops

    Science.gov (United States)

    Thompson, Michael; Tsui, Stella; Leung, Chi Fan

    2011-01-01

    A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

  8. Glare Spot Phase Doppler Anemometry

    OpenAIRE

    Hespel, Camille; Ren, Kuan Fang; Gréhan, Gérard; Onofri, Fabrice

    2006-01-01

    International audience; The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index is also necessary since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemo...

  9. Justifications shape ethical blind spots.

    Science.gov (United States)

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information. © The Author(s) 2015.

  10. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  11. Distribution of Tomato spotted wilt virus in dahlia plants.

    Science.gov (United States)

    Asano, S; Hirayama, Y; Matsushita, Y

    2017-04-01

    Tomato spotted wilt virus (TSWV) causes significant losses in the production of the ornamental plant Dahlia variabilis in Japan. The purpose of this study was to examine the distribution of TSWV in dahlia plants and identify plant parts that can be used in the selection of TSWV-free plants. The distribution of TSWV was investigated using reverse transcriptional polymerase chain reaction (RT-PCR) and tissue blot immunoassay. The detection rate of TSWV in latent infected compound leaves was the highest in the petiole, and it decreased from the veins and rachis to the lamina. The tissue blot immunoassays of the leaflets showed an uneven distribution of TSWV, especially along the edge of the leaf blade. In stems, the detection rate of TSWV was high partway up the stem compared to that in the upper and the lower parts of the stem during the vegetative growth stage. A highly uneven distribution was observed in the bulb. Our results indicated that middle parts of the stem as well as the petioles, rachis, and veins of compound leaves are suitable for detection of TSWV in dahlias. This study is the first to report uneven distribution of TSWV in dahlia plants. In this study, the distribution of Tomato spotted wilt virus (TSWV) in various parts of dahlia plants was investigated for the first time. The distribution of TSWV was uneven in compound leaves, leaflets, stems, and bulbs. The middle parts of the stem or the petiole and leaf veins should be sampled to detect TSWV when selecting healthy plants. © 2017 The Society for Applied Microbiology.

  12. Spot formation of radiation particles by electrochemical etching

    International Nuclear Information System (INIS)

    Nozaki, Tetsuya

    1999-01-01

    An electrochemical etching (ECE) spot formation from the top of chemical etching (CE) spot was confirmed by a series of experiments. One of polycarbonate (Iupilon) could not make the spot, because ECE spot had grown up before the microscope confirming the CE spot. Clear CEC spots by α-ray and neutron were found on Harzlas and Baryotrak, both improvements of CR-39. Under the same etching conditions, the growth of ECE spot on Harzlas was more rapid than Baryotrak, but both spots were almost the same. All CE spot by α-ray produced the CEC spots, but a part of CE circle spot by neutron formed them. (S.Y.)

  13. Antimicrobial potential of leaf and fruit extracts and oils of wild and cultivated edible olive

    International Nuclear Information System (INIS)

    Hussain, A.; Qurshi, I.A.; Liaqat, R.; Akhtar, S.; Aziz, I.

    2014-01-01

    Olive tree is the first botanical noted in the Bible. Leaves and fruits of olive are rich sources of Phenols, triterpenes, and flavanoids. Oleuropein obtained from the leaves extract is believed to be important therapeutic compound. Olive leaf and oils are used for the treatment of different diseases as folklore medicines by different ethnic groups in different countries of the world. The present study aims to investigate the potential antimicrobial activities of wild (Olea ferruginea) and edible (Olea europaea) olive leaf crude extracts, crude oils from ripe and unripe fruits and extra virgin oils against the selected gram positive and gram negative bacterial strains. The results show that olive leaf and oil have potential antibacterial activities against some of the gram positive and gram negative bacterial strains. However, certain strains were resistant to the extracts. It was also found that the activities were higher for the gram negative strains as compared to gram positive strains. The methanolic and ethanolic extracts were found to be more efficient in extraction than the other solvents used. Leaf extracts were more effective than the oil extracted from ripe and unripe fruits. There was no significant difference in the activities of extra virgin oils and crude leaf extracts. From the results it is concluded that the leaf extract is a cheap and effective antibacterial agent that can be used as alternative to purified oil. (author)

  14. Maize YABBY genes drooping leaf1 and drooping leaf2 affect agronomic traits by regulating leaf architecture

    Science.gov (United States)

    Leaf architectural traits, such as length, width and angle, directly influence canopy structure and light penetration, photosynthate production and overall yield. We discovered and characterized a maize (Zea mays) mutant with aberrant leaf architecture we named drooping leaf1 (drl1), as leaf blades ...

  15. Metabolic adaptation, a specialized leaf organ structure and vascular responses to diurnal N

    NARCIS (Netherlands)

    Brouwer, Paul; Bräutigam, Andrea; Buijs, Valerie A.; Tazelaar, Anne O.E.; Werf, van der Adrie; Schlüter, Urte; Reichart, Gert Jan; Bolger, Anthony; Usadel, Björn; Weber, Andreas P.M.; Schluepmann, Henriette

    2017-01-01

    Sustainable agriculture demands reduced input of man-made nitrogen (N) fertilizer, yet N2 fixation limits the productivity of crops with heterotrophic diazotrophic bacterial symbionts. We investigated floating ferns from the genus Azolla that host phototrophic diazotrophic Nostoc azollae in leaf

  16. Computational prediction of protein hot spot residues.

    Science.gov (United States)

    Morrow, John Kenneth; Zhang, Shuxing

    2012-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues.

  17. Computational Prediction of Hot Spot Residues

    Science.gov (United States)

    Morrow, John Kenneth; Zhang, Shuxing

    2013-01-01

    Most biological processes involve multiple proteins interacting with each other. It has been recently discovered that certain residues in these protein-protein interactions, which are called hot spots, contribute more significantly to binding affinity than others. Hot spot residues have unique and diverse energetic properties that make them challenging yet important targets in the modulation of protein-protein complexes. Design of therapeutic agents that interact with hot spot residues has proven to be a valid methodology in disrupting unwanted protein-protein interactions. Using biological methods to determine which residues are hot spots can be costly and time consuming. Recent advances in computational approaches to predict hot spots have incorporated a myriad of features, and have shown increasing predictive successes. Here we review the state of knowledge around protein-protein interactions, hot spots, and give an overview of multiple in silico prediction techniques of hot spot residues. PMID:22316154

  18. ESA uncovers Geminga's `hot spot'

    Science.gov (United States)

    2004-07-01

    16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

  19. [Fatty acid variation in yellowfin tuna, spotted weakfish and Florida pompano when submitted to six cooking techniques].

    Science.gov (United States)

    Castro-González, María Isabel; Maafs-Rodríguez, Ana Gabriela; Romo Pérez-Gil, Fernando

    2013-03-01

    The aim of the present study was to analyze the effect of six cooking techniques (steamed, foiled, foiled with banana leaf, baked, microwave-cooked and light frying) in the fatty acid content of Thunnus albacore (yellowfin tuna), Cynoscionnebulosus (spotted weakfish) and Trachinotuscarolinus (Florida pompano). After cooking the fish fillets, fatty acid analyses were performed using gas chromatography. Total lipids increased in all cooking techniques in tunaand spotted weakfish. Saturated fatty acids of tuna and spotted weakfish increased in three cooking techniques, while in Florida pompano only gas oven raised their content. Lightly frying generated the highest content of n-3 in tuna and spotted weakfish, and the lowest in Florida pompano, specie that presented less variation. In tuna fish, the most recommended cooking techniques are foiled with aluminum and microwave oven; for spotted weakfish, foiled with banana leaf; while Florida pompano can be prepared using all cooking methods except gas oven. This information is useful to enrich data from chemical composition tables, in which concentrations are usually presented in raw food.

  20. Effect of Plant Growth Regulators on Leaf Number, Leaf Area and Leaf Dry Matter in Grape

    Directory of Open Access Journals (Sweden)

    Zahoor Ahmad BHAT

    2011-03-01

    Full Text Available Influence of phenylureas (CPPU and brassinosteriod (BR along with GA (gibberellic acid were studied on seedless grape vegetative characteristics like leaf number, leaf area and leaf dry matter. Growth regulators were sprayed on the vines either once (7 days after fruit set or 15 days after fruit set or twice (7+15 days after fruit set. CPPU 2 ppm+BR 0.4 ppm+GA 25 ppm produced maximum number of leaves (18.78 while as untreated vines produced least leaf number (16.22 per shoot. Maximum leaf area (129.70 cm2 and dry matter content (26.51% was obtained with higher CPPU (3 ppm and BR (0.4 ppm combination along with GA 25 ppm. Plant growth regulators whether naturally derived or synthetic are used to improve the productivity and quality of grapes. The relatively high value of grapes justifies more expensive inputs. A relatively small improvement in yield or fruit quality can justify the field application of a very costly product. Application of new generation growth regulators like brassinosteroids and phenylureas like CPPU have been reported to increase the leaf number as well as leaf area and dry matter thereby indirectly influencing the fruit yield and quality in grapes.

  1. Evaluation of SPOT imagery for the estimation of grassland biomass

    Science.gov (United States)

    Dusseux, P.; Hubert-Moy, L.; Corpetti, T.; Vertès, F.

    2015-06-01

    In many regions, a decrease in grasslands and change in their management, which are associated with agricultural intensification, have been observed in the last half-century. Such changes in agricultural practices have caused negative environmental effects that include water pollution, soil degradation and biodiversity loss. Moreover, climate-driven changes in grassland productivity could have serious consequences for the profitability of agriculture. The aim of this study was to assess the ability of remotely sensed data with high spatial resolution to estimate grassland biomass in agricultural areas. A vegetation index, namely the Normalized Difference Vegetation Index (NDVI), and two biophysical variables, the Leaf Area Index (LAI) and the fraction of Vegetation Cover (fCOVER) were computed using five SPOT images acquired during the growing season. In parallel, ground-based information on grassland growth was collected to calculate biomass values. The analysis of the relationship between the variables derived from the remotely sensed data and the biomass observed in the field shows that LAI outperforms NDVI and fCOVER to estimate biomass (R2 values of 0.68 against 0.30 and 0.50, respectively). The squared Pearson correlation coefficient between observed and estimated biomass using LAI derived from SPOT images reached 0.73. Biomass maps generated from remotely sensed data were then used to estimate grass reserves at the farm scale in the perspective of operational monitoring and forecasting.

  2. Why do leaf-tying caterpillars abandon their leaf ties?

    Directory of Open Access Journals (Sweden)

    Michelle Sliwinski

    2013-09-01

    Full Text Available Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats, but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm2 leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently

  3. Agave Americana Leaf Fibers

    Directory of Open Access Journals (Sweden)

    Ashish Hulle

    2015-02-01

    Full Text Available The growing environmental problems, the problem of waste disposal and the depletion of non-renewable resources have stimulated the use of green materials compatible with the environment to reduce environmental impacts. Therefore, there is a need to design products by using natural resources. Natural fibers seem to be a good alternative since they are abundantly available and there are a number of possibilities to use all the components of a fiber-yielding crop; one such fiber-yielding plant is Agave Americana. The leaves of this plant yield fibers and all the parts of this plant can be utilized in many applications. The “zero-waste” utilization of the plant would enable its production and processing to be translated into a viable and sustainable industry. Agave Americana fibers are characterized by low density, high tenacity and high moisture absorbency in comparison with other leaf fibers. These fibers are long and biodegradable. Therefore, we can look this fiber as a sustainable resource for manufacturing and technical applications. Detailed discussion is carried out on extraction, characterization and applications of Agave Americana fiber in this paper.

  4. Physico-chemical characterization of banana varieties resistant to black leaf streak disease for industrial purposes

    Directory of Open Access Journals (Sweden)

    Rossana Catie Bueno de Godoy

    2016-01-01

    Full Text Available ABSTRACT: Cultivated bananas have very low genetic diversity making them vulnerable to diseases such as black-Sigatoka leaf spot. However, the decision to adopt a new banana variety needs to be based on a robust evaluation of agronomical and physical-chemical characteristics. Here, we characterize new banana varieties resistant to black-Sigatoka leaf spot and compare them to the most widely used traditional variety (Grand Naine. Each variety was evaluated for a range of physic-chemical attributes associated with industrial processing and flavor: pH, TTA, TSS/TTA, total sugars, reducing sugars and non-reducing sugars, humidity, total solids and yield. The Thap Maeo variety had the highest potential as a substitute for the Grand Naine variety, having higher levels of total soluble solids, reducing sugars, total sugars and humidity. The Caipira and FHIA 2 varieties also performed well in comparison with the Grand Naine variety. Cluster analysis indicated that the Grand Naine variety was closely associated with varieties from the Gross Michel subgroup (Bucaneiro, Ambrosia and Calipso and the Caipira variety, all of which come from the same AAA genomic group. It was concluded that several of the new resistant varieties could potentially substitute the traditional variety in areas affected by black-Sigatoka leaf spot disease.

  5. Watermarking spot colors in packaging

    Science.gov (United States)

    Reed, Alastair; Filler, TomáÅ.¡; Falkenstern, Kristyn; Bai, Yang

    2015-03-01

    In January 2014, Digimarc announced Digimarc® Barcode for the packaging industry to improve the check-out efficiency and customer experience for retailers. Digimarc Barcode is a machine readable code that carries the same information as a traditional Universal Product Code (UPC) and is introduced by adding a robust digital watermark to the package design. It is imperceptible to the human eye but can be read by a modern barcode scanner at the Point of Sale (POS) station. Compared to a traditional linear barcode, Digimarc Barcode covers the whole package with minimal impact on the graphic design. This significantly improves the Items per Minute (IPM) metric, which retailers use to track the checkout efficiency since it closely relates to their profitability. Increasing IPM by a few percent could lead to potential savings of millions of dollars for retailers, giving them a strong incentive to add the Digimarc Barcode to their packages. Testing performed by Digimarc showed increases in IPM of at least 33% using the Digimarc Barcode, compared to using a traditional barcode. A method of watermarking print ready image data used in the commercial packaging industry is described. A significant proportion of packages are printed using spot colors, therefore spot colors needs to be supported by an embedder for Digimarc Barcode. Digimarc Barcode supports the PANTONE spot color system, which is commonly used in the packaging industry. The Digimarc Barcode embedder allows a user to insert the UPC code in an image while minimizing perceptibility to the Human Visual System (HVS). The Digimarc Barcode is inserted in the printing ink domain, using an Adobe Photoshop plug-in as the last step before printing. Since Photoshop is an industry standard widely used by pre-press shops in the packaging industry, a Digimarc Barcode can be easily inserted and proofed.

  6. Collaboration spotting for dental science.

    Science.gov (United States)

    Leonardi, E; Agocs, A; Fragkiskos, S; Kasfikis, N; Le Goff, J M; Cristalli, M P; Luzzi, V; Polimeni, A

    2014-10-06

    The goal of the Collaboration Spotting project is to create an automatic system to collect information about publications and patents related to a given technology, to identify the key players involved, and to highlight collaborations and related technologies. The collected information can be visualized in a web browser as interactive graphical maps showing in an intuitive way the players and their collaborations (Sociogram) and the relations among the technologies (Technogram). We propose to use the system to study technologies related to Dental Science. In order to create a Sociogram, we create a logical filter based on a set of keywords related to the technology under study. This filter is used to extract a list of publications from the Web of Science™ database. The list is validated by an expert in the technology and sent to CERN where it is inserted in the Collaboration Spotting database. Here, an automatic software system uses the data to generate the final maps. We studied a set of recent technologies related to bone regeneration procedures of oro--maxillo--facial critical size defects, namely the use of Porous HydroxyApatite (HA) as a bone substitute alone (bone graft) or as a tridimensional support (scaffold) for insemination and differentiation ex--vivo of Mesenchymal Stem Cells. We produced the Sociograms for these technologies and the resulting maps are now accessible on--line. The Collaboration Spotting system allows the automatic creation of interactive maps to show the current and historical state of research on a specific technology. These maps are an ideal tool both for researchers who want to assess the state--of--the--art in a given technology, and for research organizations who want to evaluate their contribution to the technological development in a given field. We demonstrated that the system can be used for Dental Science and produced the maps for an initial set of technologies in this field. We now plan to enlarge the set of mapped

  7. Collaboration Spotting for oral medicine.

    Science.gov (United States)

    Leonardi, E; Agocs, A; Fragkiskos, S; Kasfikis, N; Le Goff, J M; Cristalli, M P; Luzzi, V; Polimeni, A

    2014-09-01

    The goal of the Collaboration Spotting project is to create an automatic system to collect information about publications and patents related to a given technology, to identify the key players involved, and to highlight collaborations and related technologies. The collected information can be visualized in a web browser as interactive graphical maps showing in an intuitive way the players and their collaborations (Sociogram) and the relations among the technologies (Technogram). We propose to use the system to study technologies related to oral medicine. In order to create a sociogram, we create a logical filter based on a set of keywords related to the technology under study. This filter is used to extract a list of publications from the Web of Science™ database. The list is validated by an expert in the technology and sent to CERN where it is inserted in the Collaboration Spotting database. Here, an automatic software system uses the data to generate the final maps. We studied a set of recent technologies related to bone regeneration procedures of oro-maxillo-facial critical size defects, namely the use of porous hydroxyapatite (HA) as a bone substitute alone (bone graft) or as a tridimensional support (scaffold) for insemination and differentiation ex vivo of mesenchymal stem cells. We produced the sociograms for these technologies and the resulting maps are now accessible on-line. The Collaboration Spotting system allows the automatic creation of interactive maps to show the current and historical state of research on a specific technology. These maps are an ideal tool both for researchers who want to assess the state-of-the-art in a given technology, and for research organizations who want to evaluate their contribution to the technological development in a given field. We demonstrated that the system can be used in oral medicine as is produced the maps for an initial set of technologies in this field. We now plan to enlarge the set of mapped technologies in

  8. Energy is not Coffee. An assessment of blind spots on energy spot-markets

    International Nuclear Information System (INIS)

    Jepma, C.J.; Spijker, E.; Van der Gaast, W.; De Jong, F.; Overmars, P.

    2006-01-01

    This study was to be the first in a series of studies on the title subject. It specifically focuses on the differences and similarities with a number of other spot-markets and aims to frame the energy spot markets and their potential development into a broader perspective. Main conclusion is that energy spot-markets differ from several other physical and non-physical spot-markets in many ways. This implies that 'perfect' energy spot-markets may inherently be (much) less perfect than other spot-markets that have approximated the stage of theoretical perfection

  9. A Global Data Set of Leaf Photosynthetic Rates, Leaf N and P, and Specific Leaf Area

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This global data set of photosynthetic rates and leaf nutrient traits was compiled from a comprehensive literature review. It includes estimates of Vcmax...

  10. A Global Data Set of Leaf Photosynthetic Rates, Leaf N and P, and Specific Leaf Area

    Data.gov (United States)

    National Aeronautics and Space Administration — This global data set of photosynthetic rates and leaf nutrient traits was compiled from a comprehensive literature review. It includes estimates of Vcmax (maximum...

  11. Solar 'hot spots' are still hot

    Science.gov (United States)

    Bai, Taeil

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

  12. Variable-spot ion beam figuring

    International Nuclear Information System (INIS)

    Wu, Lixiang; Qiu, Keqiang; Fu, Shaojun

    2016-01-01

    This paper introduces a new scheme of ion beam figuring (IBF), or rather variable-spot IBF, which is conducted at a constant scanning velocity with variable-spot ion beam collimated by a variable diaphragm. It aims at improving the reachability and adaptation of the figuring process within the limits of machine dynamics by varying the ion beam spot size instead of the scanning velocity. In contrast to the dwell time algorithm in the conventional IBF, the variable-spot IBF adopts a new algorithm, which consists of the scan path programming and the trajectory optimization using pattern search. In this algorithm, instead of the dwell time, a new concept, integral etching time, is proposed to interpret the process of variable-spot IBF. We conducted simulations to verify its feasibility and practicality. The simulation results indicate the variable-spot IBF is a promising alternative to the conventional approach.

  13. Solar hot spots are still hot

    International Nuclear Information System (INIS)

    Bai, T.

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs

  14. Classic Peripheral Signs of Subacute Bacterial Endocarditis

    Directory of Open Access Journals (Sweden)

    Yooyoung Chong

    2016-10-01

    Full Text Available A 50-year-old female patient with visual disturbances was referred for further evaluation of a heart murmur. Fundoscopy revealed a Roth spot in both eyes. A physical examination showed peripheral signs of infective endocarditis, including Osler nodes, Janeway lesions, and splinter hemorrhages. Our preoperative diagnosis was subacute bacterial endocarditis with severe aortic regurgitation. The patient underwent aortic valve replacement and was treated with intravenous antibiotics for 6 weeks postoperatively. The patient made a remarkable recovery and was discharged without complications. We report this case of subacute endocarditis with all 4 classic peripheral signs in a patient who presented with visual disturbance.

  15. Classic Peripheral Signs of Subacute Bacterial Endocarditis

    Science.gov (United States)

    Chong, Yooyoung; Han, Sung Joon; Rhee, Youn Ju; Kang, Shin Kwang; Yu, Jae Hyeon; Na, Myung Hoon

    2016-01-01

    A 50-year-old female patient with visual disturbances was referred for further evaluation of a heart murmur. Fundoscopy revealed a Roth spot in both eyes. A physical examination showed peripheral signs of infective endocarditis, including Osler nodes, Janeway lesions, and splinter hemorrhages. Our preoperative diagnosis was subacute bacterial endocarditis with severe aortic regurgitation. The patient underwent aortic valve replacement and was treated with intravenous antibiotics for 6 weeks postoperatively. The patient made a remarkable recovery and was discharged without complications. We report this case of subacute endocarditis with all 4 classic peripheral signs in a patient who presented with visual disturbance. PMID:27734006

  16. Spot and Runway Departure Advisor

    Science.gov (United States)

    Jung, Yoon Chul

    2013-01-01

    The Spot and Runway Departure Advisor (SARDA) is a research prototype of a decision support tool for ATC tower controllers to assist in manging and controlling traffic on the surface of an airport. SARDA employs a scheduler to generate an optimal runway schedule and gate push-back - spot release sequence and schedule that improves efficiency of surface operations. The advisories for ATC tower controllers are displayed on an Electronic Flight Strip (EFS) system. The human-in-the-loop simulation of the SARDA tool was conducted for east operations of Dallas-Ft. Worth International Airport (DFW) to evaluate performance of the SARDA tool and human factors, such as situational awareness and workload. The results indicates noticeable taxi delay reduction and fuel savings by using the SARDA tool. Reduction in controller workload were also observed throughout the scenario runs. The future plan includes modeling and simulation of the ramp operations of the Charlotte International Airport, and develop a decision support tool for the ramp controllers.

  17. X-ray spot filmer

    International Nuclear Information System (INIS)

    1975-01-01

    An X-ray apparatus is described which includes a spot filmer for feeding sheets of unexposed film one at a time into a vacuum evacuable cassette for exposure, and for returning exposed film sheets to an exposed film magazine. The spot filmer has a housing defining a light-tight enclosure. The film magazines are insertable through a door into the housing and into a film feed mechanism. The film feed mechanism unlatches, opens and positions the magazines; it then feeds a sheet of unexposed film into the vacuum evacuable cassette, releases the film sheet so the cassette can position the film sheet for exposure, and closes the film magazines. An orthogonal drive system positions the vacuum evacuable cassette to expose selected film sheet portions and returns the cassette to a retracted position. The film feed mechanism opens the magazines, feeds the exposed film sheet into the exposed film magazine, and closes the magazines. A film identification system is provided for forming an identifying image on a marginal portion of each film sheet

  18. Glare Spot Phase Doppler Anemometry

    Science.gov (United States)

    Hespel, Camille; Ren, Kuanfang; Gréhan, Gérard; Onofri, Fabrice

    2007-06-01

    The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index would be also interesting since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemometry which uses two large beams. In this case, the images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes in the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences between two signals, the distance and the intensity ratio of reflected and refracted parts can be obtained and they provide rich information about the particle diameter and its refractive index, as well as its velocity. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  19. Oil futures and spot markets

    International Nuclear Information System (INIS)

    Samii, M.V.

    1992-01-01

    In the last decade, the oil futures market has risen to prominence and has become a major factor in influencing oil market psychology and the crude oil market. On a normal day, over 92 thousand contracts, the equivalent of 92 million barrels per day, change hands on the New York Mercantile Exchange, NYMEX. This market has provided a vehicle for hedging against risk. At the same time, it has also created opportunities for speculation. Those who previously were unable to participate in oil market transactions can now become involved through the futures market. The large number of participants in the future market and the availability of information has made this market more efficient and transparent, relative to the crude oil market. While there has been considerable in-depth analysis of other future markets, relatively little theoretical attention has focused on that of oil. This paper looks at the following issues. First, what is the relationship between futures and spot oil prices? And secondly, are futures prices a good predictor of spot crude prices in the future? (author)

  20. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  1. Ionospheric hot spot at high latitudes

    International Nuclear Information System (INIS)

    Schunk, R.W.; Sojka, J.J.

    1982-01-01

    A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

  2. A Comparison of Leaf Area Index Maps Derived from Multi-Sensor Optical Data Acquired over Agricultural Areas

    Directory of Open Access Journals (Sweden)

    Giuseppe Satalino

    2010-06-01

    Full Text Available The objective of this study is to retrieve and compare Leaf Area Index (LAI maps from temporal series of SPOT, IKONOS and MERIS images acquired, from 2006 to 2008, over an agricultural site in Southern Italy. Results show that the root mean square error (RMSE of LAI derived from MERIS data is approximately 1 m2 m-2, slightly larger than the one obtained by using SPOT and IKONOS data. In addition, LAI retrieved from MERIS data tends to underestimate LAI retrieved from SPOT and IKONOS data, particularly at low LAI values. Nevertheless, the paper gives examples highlighting the strength of MERIS with respect to SPOT and IKONOS data in providing long and dense temporal series of LAI maps suitable to feature the temporal evolution of vegetation growth at regional scale.

  3. Roth spots seen on ophthalmoscopy: diseases with which they may be associated.

    Science.gov (United States)

    Falcone, P M; Larrison, W I

    1995-05-01

    Roth spots seen on fundoscopic examination (white-centered hemorrhages) were classically described as septic emboli in patients with subacute bacterial endocarditis (SBE). Many physicians have considered them pathognomonic for this entity. More recent evidence suggests, however, that they are nonspecific and may be found in other disease states. A review of the pathogenesis of these white-centered hemorrhages will be provided, along with some diseases other than SBE in which they may occur.

  4. SU-E-T-510: Interplay Between Spots Sizes, Spot / Line Spacing and Motion in Spot Scanning Proton Therapy

    International Nuclear Information System (INIS)

    Lee, TK

    2015-01-01

    Purpose In proton beam configuration for spot scanning proton therapy (SSPT), one can define the spacing between spots and lines of scanning as a ratio of given spot size. If the spacing increases, the number of spots decreases which can potentially decrease scan time, and so can whole treatment time, and vice versa. However, if the spacing is too large, the uniformity of scanned field decreases. Also, the field uniformity can be affected by motion during SSPT beam delivery. In the present study, the interplay between spot/ line spacing and motion is investigated. Methods We used four Gaussian-shape spot sizes with 0.5cm, 1.0cm, 1.5cm, and 2.0cm FWHM, three spot/line spacing that creates uniform field profile which are 1/3*FWHM, σ/3*FWHM and 2/3*FWHM, and three random motion amplitudes within, +/−0.3mm, +/−0.5mm, and +/−1.0mm. We planned with 2Gy uniform single layer of 10×10cm2 and 20×20cm2 fields. Then, mean dose within 80% area of given field size, contrubuting MU per each spot assuming 1cGy/MU calibration for all spot sizes, number of spots and uniformity were calculated. Results The plans with spot/line spacing equal to or smaller than 2/3*FWHM without motion create ∼100% uniformity. However, it was found that the uniformity decreases with increased spacing, and it is more pronounced with smaller spot sizes, but is not affected by scanned field sizes. Conclusion It was found that the motion during proton beam delivery can alter the dose uniformity and the amount of alteration changes with spot size which changes with energy and spot/line spacing. Currently, robust evaluation in TPS (e.g. Eclipse system) performs range uncertainty evaluation using isocenter shift and CT calibration error. Based on presented study, it is recommended to add interplay effect evaluation to robust evaluation process. For future study, the additional interplay between the energy layers and motion is expected to present volumetric effect

  5. Cosmicflows-3: Cold Spot Repeller?

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, Hélène M.; Graziani, Romain; Dupuy, Alexandra [University of Lyon, UCB Lyon 1, CNRS/IN2P3, IPN, Lyon (France); Tully, R. Brent [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Hoffman, Yehuda [Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Pomarède, Daniel [Institut de Recherche sur les Lois Fondamentales de l’Univers, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette (France)

    2017-09-20

    The three-dimensional gravitational velocity field within z ∼ 0.1 has been modeled with the Wiener filter methodology applied to the Cosmicflows-3 compilation of galaxy distances. The dominant features are a basin of attraction and two basins of repulsion. The major basin of attraction is an extension of the Shapley concentration of galaxies. One basin of repulsion, the Dipole Repeller, is located near the anti-apex of the cosmic microwave background dipole. The other basin of repulsion is in the proximate direction toward the “Cold Spot” irregularity in the cosmic microwave background. It has been speculated that a vast void might contribute to the amplitude of the Cold Spot from the integrated Sachs–Wolfe effect.

  6. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color. ...

  7. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color. ...

  8. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color. ...

  9. 7 CFR 28.413 - Middling Light Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color. ...

  10. Hot Spot Removal System: System description

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.

  11. Rocky Mountain spotted fever in children.

    Science.gov (United States)

    Woods, Charles R

    2013-04-01

    Rocky Mountain spotted fever is typically undifferentiated from many other infections in the first few days of illness. Treatment should not be delayed pending confirmation of infection when Rocky Mountain spotted fever is suspected. Doxycycline is the drug of choice even for infants and children less than 8 years old. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Rocky Mountain Spotted Fever: Statistics and Epidemiology

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search the CDC Rocky Mountain Spotted Fever (RMSF) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Rocky Mountain Spotted Fever (RMSF) Transmission Signs and Symptoms Diagnosis and Testing ...

  13. Hot Spot Removal System: System description

    International Nuclear Information System (INIS)

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System''s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section

  14. Biophysical control of leaf temperature

    Science.gov (United States)

    Dong, N.; Prentice, I. C.; Wright, I. J.

    2014-12-01

    In principle sunlit leaves can maintain their temperatures within a narrower range than ambient temperatures. This is an important and long-known (but now overlooked) prediction of energy balance theory. Net radiation at leaf surface in steady state (which is reached rapidly) must be equal to the combination of sensible and latent heat exchanges with surrounding air, the former being proportional to leaf-to-air temperature difference (ΔT), the latter to the transpiration rate. We present field measurements of ΔT which confirm the existence of a 'crossover temperature' in the 25-30˚C range for species in a tropical savanna and a tropical rainforest environment. This finding is consistent with a simple representation of transpiration as a function of net radiation and temperature (Priestley-Taylor relationship) assuming an entrainment factor (ω) somewhat greater than the canonical value of 0.26. The fact that leaves in tropical forests are typically cooler than surrounding air, often already by solar noon, is consistent with a recently published comparison of MODIS day-time land-surface temperatures with air temperatures. Theory further predicts a strong dependence of leaf size (which is inversely related to leaf boundary-layer conductance, and therefore to absolute magnitude of ΔT) on moisture availability. Theoretically, leaf size should be determined by either night-time constraints (risk of frost damage to active leaves) or day-time constraints (risk of heat stress damage),with the former likely to predominate - thereby restricting the occurrence of large leaves - at high latitudes. In low latitudes, daytime maximum leaf size is predicted to increase with temperature, provided that water is plentiful. If water is restricted, however, transpiration cannot proceed at the Priestley-Taylor rate, and it quickly becomes advantageous for plants to have small leaves, which do not heat up much above the temperature of their surroundings. The difference between leaf

  15. Waiting for the Leaf; Warten auf den Leaf

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, Jan

    2012-01-15

    Nissan will be the first manufacturer to launch an electric vehicle of the VW Golf category in the German market. With a mileage of about 170 km and a roomy passenger compartment, the Leaf promises much comfort. In the US market, it was launched two years ago. Was it worth while waiting for?.

  16. Lesion bacterial communities in American lobsters with diet-induced shell disease.

    Science.gov (United States)

    Quinn, Robert A; Metzler, Anita; Tlusty, Michael; Smolowitz, Roxanna M; Leberg, Paul; Chistoserdov, Andrei Y

    2012-04-26

    In southern New England, USA, shell disease affects the profitability of the American lobster Homarus americanus fishery. In laboratory trials using juvenile lobsters, exclusive feeding of herring Clupea harengus induces shell disease typified initially by small melanized spots that progress into distinct lesions. Amongst a cohabitated, but segregated, cohort of 11 juvenile lobsters fed exclusively herring, bacterial communities colonizing spots and lesions were investigated by denaturing gradient gel electrophoresis of 16S rDNA amplified using 1 group-specific and 2 universal primer sets. The Bacteroidetes and Proteobacteria predominated in both spots and lesions and included members of the orders Flavobacteriales (Bacteriodetes), Rhodobacterales, Rhodospirillales and Rhizobiales (Alphaproteobacteria), Xanthomonadales (Gammaproteobacteria) and unclassified Gammaproteobacteria. Bacterial communities in spot lesions displayed more diversity than communities with larger (older) lesions, indicating that the lesion communities stabilize over time. At least 8 bacterial types persisted as lesions developed from spots. Aquimarina 'homaria', a species commonly cultured from lesions present on wild lobsters with epizootic shell disease, was found ubiquitously in spots and lesions, as was the 'Candidatus Kopriimonas aquarianus', implicating putative roles of these species in diet-induced shell disease of captive lobsters.

  17. Crack imaging by pulsed laser spot thermography

    International Nuclear Information System (INIS)

    Li, T; Almond, D P; Rees, D A S; Weekes, B

    2010-01-01

    A surface crack close to a spot heated by a laser beam impedes lateral heat flow and produces alterations to the shape of the thermal image of the spot that can be monitored by thermography. A full 3D simulation has been developed to simulate heat flow from a laser heated spot in the proximity of a crack. The modelling provided an understanding of the ways that different parameters affect the thermal images of laser heated spots. It also assisted in the development of an efficient image processing strategy for extracting the scanned cracks. Experimental results show that scanning pulsed laser spot thermography has considerable potential as a remote, non-contact crack imaging technique.

  18. Laser Spot Detection Based on Reaction Diffusion.

    Science.gov (United States)

    Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J M; Dormido, Raquel; Duro, Natividad

    2016-03-01

    Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

  19. Laser Spot Detection Based on Reaction Diffusion

    Directory of Open Access Journals (Sweden)

    Alejandro Vázquez-Otero

    2016-03-01

    Full Text Available Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

  20. Rocky Mountain spotted fever in Argentina.

    Science.gov (United States)

    Paddock, Christopher D; Fernandez, Susana; Echenique, Gustavo A; Sumner, John W; Reeves, Will K; Zaki, Sherif R; Remondegui, Carlos E

    2008-04-01

    We describe the first molecular confirmation of Rickettsia rickettsii, the cause of Rocky Mountain spotted fever (RMSF), from a tick vector, Amblyomma cajennense, and from a cluster of fatal spotted fever cases in Argentina. Questing A. cajennense ticks were collected at or near sites of presumed or confirmed cases of spotted fever rickettsiosis in Jujuy Province and evaluated by polymerase chain reaction assays for spotted fever group rickettsiae. DNA of R. rickettsii was amplified from a pool of A. cajennense ticks and from tissues of one of four patients who died during 2003-2004 after illnesses characterized by high fever, severe headache, myalgias, and petechial rash. The diagnosis of spotted fever rickettsiosis was confirmed in the other patients by indirect immunofluorescence antibody and immunohistochemical staining techniques. These findings show the existence of RMSF in Argentina and emphasize the need for clinicians throughout the Americas to consider RMSF in patients with febrile rash illnesses.

  1. Effect of nitrogen supply on leaf appearance, leaf growth, leaf nitrogen economy and photosynthetic capacity in maize (Zea mays L.)

    NARCIS (Netherlands)

    Vos, J.; Putten, van der P.E.L.; Birch, C.J.

    2005-01-01

    Leaf area growth and nitrogen concentration per unit leaf area, Na (g m-2 N) are two options plants can use to adapt to nitrogen limitation. Previous work indicated that potato (Solanum tuberosum L.) adapts the size of leaves to maintain Na and photosynthetic capacity per unit leaf area. This paper

  2. Spectral reflectance relationships to leaf water stress

    Science.gov (United States)

    Ripple, William J.

    1986-01-01

    Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

  3. Effects of tillage operations and plant density on leaf spot disease ...

    African Journals Online (AJOL)

    Two seasons experiments conducted in 2002 and 2003 revealed that Tillage operations significantly influenced leafspot disease severity; Percentage lodging 3.14; 2.08 and Grain yield 3.02; 3.84 in 2002 and 2003 respectively. Plant density also had significant difference on leafspot disease severity; Percentage lodging ...

  4. Severity of angular leaf spot and rust diseases on common beans in ...

    African Journals Online (AJOL)

    ACSS

    5.3, respectively. Key words: Common beans, disease management, Phaseolus vulgaris, Pseudocercospora griseola, .... Pearson product- moment ..... SAS Institute. 1989. SAS/STAT User's. Guide (version 6, vol. 1, 4th ed.), Cary: SAS Institute ...

  5. First report of alternaria leaf spot of banana caused by Alternaria alternata in the United States

    Science.gov (United States)

    Research efforts were initiated in 2003 to identify and introduce banana (Musa spp.) cultivars suitable for production in Georgia. In spring and summer 2012, seven of the cultivars (Veinte Cohol, Novaria, Cacambou, Chinese Cavendish, Raja Puri, Blue Torres Island, and African Red) grown in the field...

  6. Soil moisture mediated interaction between Polygonatum biflorum and leaf spot disease

    Science.gov (United States)

    Robert J. II Warren; Erin Mordecai

    2010-01-01

    Fungal pathogens can regulate the abundance and distribution of natural plant populations by inhibiting the growth, survival, and reproduction of their hosts. The abiotic environment is a crucial component in host–pathogen interactions in natural plant populations as favorable conditions drive pathogen development, reproduction, and persistence. Foliar plant pathogens...

  7. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2011-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from

  8. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2012-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from

  9. Disease variation and chemical control of Ramularia leaf spot in sugar beet

    DEFF Research Database (Denmark)

    Thach, Tine; Munk, Lisa; Hansen, Anne Lisbet

    2013-01-01

    in field trials, a semi-field trial and an in vitro test using the compounds pyraclostrobin, epoxiconazole, difenoconazole and propiconazole. Dose response trials with epoxiconazole from two seasons showed both reduced efficacy and yield responses from low doses. They also proved that the optimal input...... preventive and curative effects with 84–100% disease control from epoxiconazole, difenoconazole and pyraclostrobin. In order to optimize an IPM control strategy better forecasting systems are needed along with cultivars providing higher levels of resistance to the disease....

  10. An evolutionary perspective on leaf economics : Phylogenetics of leaf mass per area in vascular plants

    NARCIS (Netherlands)

    Flores, Olivier; Garnier, Eric; Wright, Ian J.; Reich, Peter B.; Pierce, Simon; Diaz, Sandra; Pakeman, Robin J.; Rusch, Graciela M.; Bernard-Verdier, Maud; Testi, Baptiste; Bakker, Jan P.; Bekker, Renee M.; Cerabolini, Bruno E. L.; Ceriani, Roberta M.; Cornu, Guillaume; Cruz, Pablo; Delcamp, Matthieu; Dolezal, Jiri; Eriksson, Ove; Fayolle, Adeline; Freitas, Helena; Golodets, Carly; Gourlet-Fleury, Sylvie; Hodgson, John G.; Brusa, Guido; Kleyer, Michael; Kunzmann, Dieter; Lavorel, Sandra; Papanastasis, Vasilios P.; Perez-Harguindeguy, Natalia; Vendramini, Fernanda; Weiher, Evan

    In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This "worldwide leaf economics spectrum" consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf

  11. The Nissan LEAF electric powertrain

    Energy Technology Data Exchange (ETDEWEB)

    Nakazawa, Shinsuke [Nissan Motor Co., Ltd. (Japan)

    2011-07-01

    The need for CO{sub 2} reduction as a countermeasure to global warming, and to move away from our dependence on fossil fuels as a countermeasure to energy security are urgent issues. One of the ultimate goals to achieving these targets is to develop a 'Zero emission car' such as an electric vehicle or a fuel cell vehicle, along with the manufacturing of clean energy. Nissan have developed a new powertrain for the electric vehicle, and have installed it in the Nissan LEAF. Sales of the Nissan LEAF started in North America, Europe and Japan in 2010, with plans to sell it globally by 2012. In order to achieve an improved driving range, power performance and drivability performance, Nissan have adapted a high efficiency synchronous motor, a water-cooled inverter, and reducer. Moreover, the Nissan LEAF has the capability of a 3.3kW AC charge and a 50kW DC quick charge. This presentation will introduce the features of the electric powertrain adopted for Nissan LEAF. (orig.)

  12. 7 CFR 30.2 - Leaf tobacco.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf tobacco. 30.2 Section 30.2 Agriculture... Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO STOCKS AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.2 Leaf...

  13. 7 CFR 29.3035 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.3035 Section 29.3035 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf structure. The cell development of a leaf as indicated by its porosity or solidity. (See Elements...

  14. 7 CFR 29.6023 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.6023 Section 29.6023 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6023 Leaf structure. The cell development of a leaf as indicated by its...

  15. 7 CFR 29.1030 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.1030 Section 29.1030 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1030 Leaf structure. The cell development of a leaf as indicated by its porosity. (See...

  16. 7 CFR 29.3527 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.3527 Section 29.3527 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3527 Leaf structure. The cell development of a leaf as indicated by its porosity. (See...

  17. 7 CFR 29.3526 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling...

  18. 7 CFR 29.3034 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and...

  19. 7 CFR 29.6022 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results...

  20. Betel leaf in stoma care.

    Science.gov (United States)

    Banu, Tahmina; Talukder, Rupom; Chowdhury, Tanvir Kabir; Hoque, Mozammel

    2007-07-01

    Construction of a stoma is a common procedure in pediatric surgical practice. For care of these stomas, commercially available devices such as ostomy bag, either disposable or of longer duration are usually used. These are expensive, particularly in countries like Bangladesh, and proper-sized ones are not always available. We have found an alternative for stoma care, betel leaf, which is suitable for Bangladeshis. We report the outcome of its use. After construction of stoma, at first zinc oxide paste was applied on the peristomal skin. A betel leaf with shiny, smooth surface outwards and rough surface inwards was put over the stoma with a hole made in the center according to the size of stoma. Another intact leaf covers the stomal opening. When bowel movement occurs, the overlying intact leaf was removed and the fecal matter was washed away from both. The leaves were reused after cleaning. Leaves were changed every 2 to 3 days. From June 1998 to December 2005, in the department of pediatric surgery, Chittagong Medical College and Hospital, Chittagong, Bangladesh, a total of 623 patients had exteriorization of bowel. Of this total, 495 stomas were cared for with betel leaves and 128 with ostomy bags. Of 623 children, 287 had sigmoid colostomy, 211 had transverse colostomy, 105 had ileostomy, and 20 had jejunostomy. Of the 495 children under betel leaf stoma care, 13 patients (2.6%) developed skin excoriation. There were no allergic reactions. Of the 128 patients using ostomy bag, 52 (40.65%) had skin excoriation. Twenty-four (18.75%) children developed some allergic reactions to adhesive. Monthly costs for betel leaves were 15 cents (10 BDT), whereas ostomy bags cost about US$24. In the care of stoma, betel leaves are cheap, easy to handle, nonirritant, and nonallergic.

  1. Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups.

    Science.gov (United States)

    Reich, Peter B; Walters, Michael B; Ellsworth, David S; Vose, James M; Volin, John C; Gresham, Charles; Bowman, William D

    1998-05-01

    Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf dark respiration rate (R d ) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (A max ). However, it is not known whether such scaling, if it exists, is similar among disparate biomes and plant functional types. We tested this idea by examining the interspecific relationships between R d measured at a standard temperature and leaf life-span, N, SLA and A max for 69 species from four functional groups (forbs, broad-leafed trees and shrubs, and needle-leafed conifers) in six biomes traversing the Americas: alpine tundra/subalpine forest, Colorado; cold temperate forest/grassland, Wisconsin; cool temperate forest, North Carolina; desert/shrubland, New Mexico; subtropical forest, South Carolina; and tropical rain forest, Amazonas, Venezuela. Area-based R d was positively related to area-based leaf N within functional groups and for all species pooled, but not when comparing among species within any site. At all sites, mass-based R d (R d-mass ) decreased sharply with increasing leaf life-span and was positively related to SLA and mass-based A max and leaf N (leaf N mass ). These intra-biome relationships were similar in shape and slope among sites, where in each case we compared species belonging to different plant functional groups. Significant R d-mass -N mass relationships were observed in all functional groups (pooled across sites), but the relationships differed, with higher R d at any given leaf N in functional groups (such as forbs) with higher SLA and shorter leaf life-span. Regardless of biome or functional group, R d-mass was well predicted by all combinations of leaf life-span, N mass and/or SLA (r 2 ≥ 0.79, P morphological, chemical and metabolic traits.

  2. Bacterial lung abscess

    International Nuclear Information System (INIS)

    Groskin, S.A.; Panicek, D.M.; Ewing, D.K.; Rivera, F.; Math, K.; Teixeira, J.; Heitzman, E.R.

    1987-01-01

    A retrospective review of patients with bacterial lung abscess was carried out. Demographic, clinical, and radiographical features of this patient group are compared with similar data from patients with empyema and/or cavitated lung carcinoma; differential diagnostic points are stressed. The entity of radiographically occult lung abscess is discussed. Complications associated with bacterial lung abscess are discussed. Current therapeutic options and treatment philosophy for patients with bacterial lung abscess are noted

  3. Volume higher; spot price ranges widen

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the October 1994 uranium market summary. During this reporting period, volume on the spot concentrates market doubled. Twelve deals took place: three in the spot concentrates market, one in the medium and long-term market, four in the conversion market, and four in the enrichment market. The restricted price range widened due to higher prices at the top end of the range, while the unrestricted price range widened because of lower prices at the bottom end. Spot conversion prices were higher, and enrichment prices were unchanged

  4. 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 ...

  5. Relationships between phyllosphere bacterial communities and plant functional traits in a neotropical forest

    Science.gov (United States)

    Kembel, Steven W.; O’Connor, Timothy K.; Arnold, Holly K.; Hubbell, Stephen P.; Wright, S. Joseph; Green, Jessica L.

    2014-01-01

    The phyllosphere—the aerial surfaces of plants, including leaves—is a ubiquitous global habitat that harbors diverse bacterial communities. Phyllosphere bacterial communities have the potential to influence plant biogeography and ecosystem function through their influence on the fitness and function of their hosts, but the host attributes that drive community assembly in the phyllosphere are poorly understood. In this study we used high-throughput sequencing to quantify bacterial community structure on the leaves of 57 tree species in a neotropical forest in Panama. We tested for relationships between bacterial communities on tree leaves and the functional traits, taxonomy, and phylogeny of their plant hosts. Bacterial communities on tropical tree leaves were diverse; leaves from individual trees were host to more than 400 bacterial taxa. Bacterial communities in the phyllosphere were dominated by a core microbiome of taxa including Actinobacteria, Alpha-, Beta-, and Gammaproteobacteria, and Sphingobacteria. Host attributes including plant taxonomic identity, phylogeny, growth and mortality rates, wood density, leaf mass per area, and leaf nitrogen and phosphorous concentrations were correlated with bacterial community structure on leaves. The relative abundances of several bacterial taxa were correlated with suites of host plant traits related to major axes of plant trait variation, including the leaf economics spectrum and the wood density–growth/mortality tradeoff. These correlations between phyllosphere bacterial diversity and host growth, mortality, and function suggest that incorporating information on plant–microbe associations will improve our ability to understand plant functional biogeography and the drivers of variation in plant and ecosystem function. PMID:25225376

  6. Finding your innovation sweet spot.

    Science.gov (United States)

    Goldenberg, Jacob; Horowitz, Roni; Levav, Amnon; Mazursky, David

    2003-03-01

    Most new product ideas are either uninspired or impractical. So how can developers hit the innovation sweet spot--far enough from existing products to attract real interest but close enough that they are feasible to make and market? They can apply five innovation patterns that manipulate existing components of a product and its immediate environment to come up with something both ingenious and viable, say the authors. The subtraction pattern works by removing product components, particularly those that seem desirable or indispensable. Think of the legless high chair that attaches to the kitchen table. The multiplication pattern makes one or more copies of an existing component, then alters those copies in some important way. For example, the Gillette double-bladed razor features a second blade that cuts whiskers at a slightly different angle. By dividing an existing product into its component parts--the division pattern--you can see something that was an integrated whole in an entirely different light. Think of the modern home stereo--it has modular speakers, tuners, and CD and tape players, which allow users to customize their sound systems. The task unification pattern involves assigning a new task to an existing product element or environmental attribute, thereby unifying two tasks in a single component. An example is the defrosting filament in an automobile windshield that also serves as a radio antenna. Finally, the attribute dependency pattern alters or creates the dependent relationships between a product and its environment. For example, by creating a dependent relationship between lens color and external lighting conditions, eyeglass developers came up with a lens that changes color when exposed to sunlight.

  7. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H 2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  8. A telemetry experiment on spotted grunter Pomadasys ...

    African Journals Online (AJOL)

    associated fish in South Africa was investigated by conducting a tracking experiment on spotted grunter Pomadasys commersonnii in the East Kleinemonde Estuary. The telemetry equipment comprised two VEMCO V8 transmitters and a ...

  9. Detecting Blind Spot By Using Ultrasonic Sensor

    Directory of Open Access Journals (Sweden)

    T. S. Ajay

    2015-08-01

    Full Text Available Safety remains a top concern for automobile industries and new-car shoppers. Detection of Blind Spots is a major concern for safety issues. So automobiles have been constantly updating their products with new technologies to detect blind spots so that they can add more safety to the vehicle and also reduce the road accidents. Almost 1.5 million people die in road accidents each year. Blind spot of an automobile is the region of the vehicle which cannot be observed properly while looking either through side or rear mirror view. To meet the above requirements this paper describes detecting blind spot by using ultrasonic sensor and controlling the direction of car by automatic steering. The technology embedded in the system is capable of automatically steer the vehicle away from an obstacle if the system determines that a collision is impending or if the vehicle is in the vicinity of our car.

  10. How Many Spots Does a Cheetah Have?

    Science.gov (United States)

    Reed, Kristine M.

    2000-01-01

    Describes first grade students' mathematical investigation of the number of spots on a cheetah. The exploration of counting and estimation strategies that grew from the investigation gives evidence that mathematicians come in all ages. (ASK)

  11. X-ray spot film device

    International Nuclear Information System (INIS)

    1981-01-01

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  12. Antimicrobial activity of Piper nigrum L. and Cassia didymobotyra L. leaf extract on selected food borne pathogens

    Directory of Open Access Journals (Sweden)

    Mohd. Sayeed Akthar

    2014-09-01

    Full Text Available Objective: To investigate the antimicrobial activity of leaf extract of Piper nigrum (P. nigrum and Cassia didymobotyra (C. didymobotyra (aqueous, methanol, ethanol and petroleum ether against the food borne pathogenic bacteria [Staphylococcus aureus (S. aureus, Escherichia coli (E. coli, Salmonella typhimurium and Pseudomonas aeruginosa] and fungi [Aspergillus spp. and Candida albicans (C. albicans] and also to investigate the presence of various phytochemicals in the leaf extracts of tested plants. Methods: The antimicrobial activity was determined by disc diffusion method. Minimum inhibitory concentration (MIC, minimum bactericidal and fungicidal concentration were determined by serial dilution method. Results: Methanol leaf extract of test plants exhibited greater antimicrobial activity against the selected bacterial and fungal strains. The MIC results showed that ethanol, methanol and petroleum ether leaf extract of P. nigrum inhibited the growth of S. aureus and E. coli at concentration of 12.5 mg/mL. While, ethanol and methanol leaf extracts of C. didymobotyra inhibited the growth of S. aureus at concentration of 6.25 mg/mL. The MIC values for ethanol, methanol and petroleum ether leaf extract of P. nigrum inhibited the growth of C. albicans at concentration of 25.0 mg/mL. While, it was reported that at concentration of 12.5 mg/mL methanol leaf extract of P. nigrum was against the Aspergillus spp. The MIC values of methanol leaf extract of C. didymobotyra inhibited the growth of C. albicans and Aspergillus spp. at concentration of 12.5 mg/mL and 6.25 mg/mL, respectively. The minimum bactericidal concentration of ethanol, methanol leaf extract of P. nigrum for E. coli and ethanol, methanol leaf extract of C. didymobotyra for S. aureus was recorded at concentration 12.5 mg/mL. The minimum fungicidal concentration of ethanol and methanol leaf extract of P. nigrum and C. didymobotyra on C. albicans was recorded at concentration of 25.0 mg

  13. Analysis of Peanut Leaf Proteome

    DEFF Research Database (Denmark)

    Ramesh, R.; Suravajhala, Prashanth; Pechan, T.

    2010-01-01

    Peanut (Arachis hypogaea) is one of the most important sources of plant protein. Current selection of genotypes requires molecular characterization of available populations. Peanut genome database has several EST cDNAs which can be used to analyze gene expression. Analysis of proteins is a direct...... approach to define function of their associated genes. Proteome analysis linked to genome sequence information is critical for functional genomics. However, the available protein expression data is extremely inadequate. Proteome analysis of peanut leaf was conducted using two-dimensional gel...... electrophoresis in combination with sequence identification using MALDI/TOF to determine their identity and function related to growth, development and responses to stresses. Peanut leaf proteins were resolved into 300 polypeptides with pI values between 3.5 and 8.0 and relative molecular masses from 12 to 100 k...

  14. Changes of Bacterial Diversity Depend on the Spoilage of Fresh Vegetables

    Directory of Open Access Journals (Sweden)

    Dong Hwan Lee

    2011-04-01

    Full Text Available Almost 10~30% of vegetables were discarded by the spoilage from farms to tables. After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. This investigation was conducted to extent the knowledge of relationship the spoilage of vegetables and the diversity of microbes. The total aerobic bacterial numbers in fresh lettuce, perilla leaf, and chicory were 2.6~2.7×106, 4.6×105, 1.2×106 CFU/g of fresh weight, respectively. The most common bacterial species were Pseudomonas spp., Alysiella spp., and Burkholderia spp., and other 18 more genera were involved in. After one week of incubation of those vegetables at 28℃, the microbial diversity had been changed. The total aerobic bacterial numbers increased to 1.1~4.6×108, 4.9×107, and 7.6×108 CFU/g of fresh weight for lettuce, perilla leaf, and chicory that is about 102 times increased bacterial numbers than that before spoilage. However, the diversity of microbes isolated had been simplified and fewer bacterial species had been isolated. The most bacterial population (~48% was taken up by Pseudomonas spp., and followed by Arthrobacter spp. and Bacillus spp. The spoilage activity of individual bacterial isolates had been tested using axenic lettuce plants. Among tested isolates, Pseudomonas fluorescence and Pantoea agglomerans caused severe spoilage on lettuce.

  15. Can Leaf Spectroscopy Predict Leaf and Forest Traits Along a Peruvian Tropical Forest Elevation Gradient?

    Science.gov (United States)

    Doughty, Christopher E.; Santos-Andrade, P. E.; Goldsmith, G. R.; Blonder, B.; Shenkin, A.; Bentley, L. P.; Chavana-Bryant, C.; Huaraca-Huasco, W.; Díaz, S.; Salinas, N.; Enquist, B. J.; Martin, R.; Asner, G. P.; Malhi, Y.

    2017-11-01

    High-resolution spectroscopy can be used to measure leaf chemical and structural traits. Such leaf traits are often highly correlated to other traits, such as photosynthesis, through the leaf economics spectrum. We measured VNIR (visible-near infrared) leaf reflectance (400-1,075 nm) of sunlit and shaded leaves in 150 dominant species across ten, 1 ha plots along a 3,300 m elevation gradient in Peru (on 4,284 individual leaves). We used partial least squares (PLS) regression to compare leaf reflectance to chemical traits, such as nitrogen and phosphorus, structural traits, including leaf mass per area (LMA), branch wood density and leaf venation, and "higher-level" traits such as leaf photosynthetic capacity, leaf water repellency, and woody growth rates. Empirical models using leaf reflectance predicted leaf N and LMA (r2 > 30% and %RMSE < 30%), weakly predicted leaf venation, photosynthesis, and branch density (r2 between 10 and 35% and %RMSE between 10% and 65%), and did not predict leaf water repellency or woody growth rates (r2<5%). Prediction of higher-level traits such as photosynthesis and branch density is likely due to these traits correlations with LMA, a trait readily predicted with leaf spectroscopy.

  16. Modeling deflagration waves out of hot spots

    Science.gov (United States)

    Partom, Yehuda

    2017-01-01

    It is widely accepted that shock initiation and detonation of heterogeneous explosives comes about by a two-step process known as ignition and growth. In the first step a shock sweeping through an explosive cell (control volume) creates hot spots that become ignition sites. In the second step, deflagration waves (or burn waves) propagate out of those hot spots and transform the reactant in the cell into reaction products. The macroscopic (or average) reaction rate of the reactant in the cell depends on the speed of those deflagration waves and on the average distance between neighboring hot spots. Here we simulate the propagation of deflagration waves out of hot spots on the mesoscale in axial symmetry using a 2D hydrocode, to which we add heat conduction and bulk reaction. The propagation speed of the deflagration waves may depend on both pressure and temperature. It depends on pressure for quasistatic loading near ambient temperature, and on temperature at high temperatures resulting from shock loading. From the simulation we obtain deflagration fronts emanating out of the hot spots. For 8 to 13 GPa shocks, the emanating fronts propagate as deflagration waves to consume the explosive between hot spots. For higher shock levels deflagration waves may interact with the sweeping shock to become detonation waves on the mesoscale. From the simulation results we extract average deflagration wave speeds.

  17. Unblinding the dark matter blind spots

    International Nuclear Information System (INIS)

    Han, Tao; Kling, Felix

    2017-01-01

    The dark matter (DM) blind spots in the Minimal Supersymmetric Standard Model (MSSM) refer to the parameter regions where the couplings of the DM particles to the Z-boson or the Higgs boson are almost zero, leading to vanishingly small signals for the DM direct detections. In this paper, we carry out comprehensive analyses for the DM searches under the blind-spot scenarios in MSSM. Guided by the requirement of acceptable DM relic abundance, we explore the complementary coverage for the theory parameters at the LHC, the projection for the future underground DM direct searches, and the indirect searches from the relic DM annihilation into photons and neutrinos. We find that (i) the spin-independent (SI) blind spots may be rescued by the spin-dependent (SD) direct detection in the future underground experiments, and possibly by the indirect DM detections from IceCube and SuperK neutrino experiments; (ii) the detection of gamma rays from Fermi-LAT may not reach the desirable sensitivity for searching for the DM blind-spot regions; (iii) the SUSY searches at the LHC will substantially extend the discovery region for the blind-spot parameters. As a result, the dark matter blind spots thus may be unblinded with the collective efforts in future DM searches.

  18. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

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

    2010-01-01

    . 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...

  19. Spot weld arrangement effects on the fatigue behavior of multi-spot welded joints

    International Nuclear Information System (INIS)

    Hassanifard, Soran; Zehsaz, Mohammad; Esmaeili, Firooz

    2011-01-01

    In the present study, the effects of spot weld arrangements in multi-spot welded joints on the fatigue behavior of the joints are studied. Three different four-spot welded joints are considered: one-row four-spot parallel to the loading direction, one-row four-spot perpendicular to the loading direction and two-row four-spot weld specimens. The experimental fatigue test results reveal that the differences between the fatigue lives of three spot welded types in the low cycle regime are more considerable than those in the high cycle regime. However, all kinds of spot weld specimens have similar fatigue strength when approaching a million cycles. A non-linear finite element analysis is performed to obtain the relative stress gradients, effective distances and notch strength reduction factors based on the volumetric approach. The work here shows that the volumetric approach does a very good job in predicting the fatigue life of the multi-spot welded joints

  20. 7 CFR 28.423 - Middling Spotted Color.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Spotted Color. 28.423 Section 28.423... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Spotted Cotton § 28.423 Middling Spotted Color. Middling Spotted Color is color which is within the range represented by a set of samples in the custody of...

  1. Relationship between hot spot residues and ligand binding hot spots in protein-protein interfaces.

    Science.gov (United States)

    Zerbe, Brandon S; Hall, David R; Vajda, Sandor; Whitty, Adrian; Kozakov, Dima

    2012-08-27

    In the context of protein-protein interactions, the term "hot spot" refers to a residue or cluster of residues that makes a major contribution to the binding free energy, as determined by alanine scanning mutagenesis. In contrast, in pharmaceutical research, a hot spot is a site on a target protein that has high propensity for ligand binding and hence is potentially important for drug discovery. Here we examine the relationship between these two hot spot concepts by comparing alanine scanning data for a set of 15 proteins with results from mapping the protein surfaces for sites that can bind fragment-sized small molecules. We find the two types of hot spots are largely complementary; the residues protruding into hot spot regions identified by computational mapping or experimental fragment screening are almost always themselves hot spot residues as defined by alanine scanning experiments. Conversely, a residue that is found by alanine scanning to contribute little to binding rarely interacts with hot spot regions on the partner protein identified by fragment mapping. In spite of the strong correlation between the two hot spot concepts, they fundamentally differ, however. In particular, while identification of a hot spot by alanine scanning establishes the potential to generate substantial interaction energy with a binding partner, there are additional topological requirements to be a hot spot for small molecule binding. Hence, only a minority of hot spots identified by alanine scanning represent sites that are potentially useful for small inhibitor binding, and it is this subset that is identified by experimental or computational fragment screening.

  2. SPOTTED STAR LIGHT CURVES WITH ENHANCED PRECISION

    International Nuclear Information System (INIS)

    Wilson, R. E.

    2012-01-01

    The nearly continuous timewise coverage of recent photometric surveys is free of the large gaps that compromise attempts to follow starspot growth and decay as well as motions, thereby giving incentive to improve computational precision for modeled spots. Due to the wide variety of star systems in the surveys, such improvement should apply to light/velocity curve models that accurately include all the main phenomena of close binaries and rotating single stars. The vector fractional area (VFA) algorithm that is introduced here represents surface elements by small sets of position vectors so as to allow accurate computation of circle-triangle overlap by spherical geometry. When computed by VFA, spots introduce essentially no noticeable scatter in light curves at the level of one part in 10,000. VFA has been put into the Wilson-Devinney light/velocity curve program and all logic and mathematics are given so as to facilitate entry into other such programs. Advantages of precise spot computation include improved statistics of spot motions and aging, reduced computation time (intrinsic precision relaxes needs for grid fineness), noise-free illustration of spot effects in figures, and help in guarding against false positives in exoplanet searches, where spots could approximately mimic transiting planets in unusual circumstances. A simple spot growth and decay template quantifies time profiles, and specifics of its utilization in differential corrections solutions are given. Computational strategies are discussed, the overall process is tested in simulations via solutions of synthetic light curve data, and essential simulation results are described. An efficient time smearing facility by Gaussian quadrature can deal with Kepler mission data that are in 30 minute time bins.

  3. Leaf Diseases On Eucalyptus Pellita F. Muell In Plantation Of Pt Surya Hutani Jaya At Sebulu East Kalimantan

    Directory of Open Access Journals (Sweden)

    Iin Arsensi

    2015-08-01

    Full Text Available Eucalyptus pellita is often grown in monoculture can be susceptible to disease whether grown in the nursery or the field. Currently in the plantation of PT Surya Hutani Jaya Sebulu is developing E. pellita derived from seed and clonal. The results were then called family. To determine the benefits to trees the company deliberately does not preserve this area so there will be generated trees family that excel in both productivity and resistance to pests and diseases. This study is aimed at determining the symptoms and signs of disease on the leaves the microorganisms that cause disease on the leaves as well as the incidence and severity of pathogen that attacks the leaves of E. pellita. The research was conducted at PT Surya Hutani Jaya Sebulu Kutai Kartanegara Regency East Kalimantan and continued with the identification of pathogens at the Laboratory of Forest Protection Faculty of Forestry University of Mulawarman. The object of this research was E. pellita of a 6 year old plantation spacing of 3 amp61620 2 m. The origin of E. pellita is a clone from Riau. Symptoms of the disease found at the progeny test were leaf spot and leaf blight. The pathogens were Cercospora sp. Pestalotia sp. Curvularia sp. Bipolaris sp. Marsonina sp. and Dactylaria sp. The incidence of leaf spot pathogen was 83.3 and leaf blight was 80.6 with the severity of 9.7 and 12.5 respectively.

  4. Metamorphosis of a butterfly-associated bacterial community.

    Science.gov (United States)

    Hammer, Tobin J; McMillan, W Owen; Fierer, Noah

    2014-01-01

    Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar) and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  5. Metamorphosis of a butterfly-associated bacterial community.

    Directory of Open Access Journals (Sweden)

    Tobin J Hammer

    Full Text Available Butterflies are charismatic insects that have long been a focus of biological research. They are also habitats for microorganisms, yet these microbial symbionts are little-studied, despite their likely importance to butterfly ecology and evolution. In particular, the diversity and composition of the microbial communities inhabiting adult butterflies remain uncharacterized, and it is unknown how the larval (caterpillar and adult microbiota compare. To address these knowledge gaps, we used Illumina sequencing of 16S rRNA genes from internal bacterial communities associated with multiple life stages of the neotropical butterfly Heliconius erato. We found that the leaf-chewing larvae and nectar- and pollen-feeding adults of H. erato contain markedly distinct bacterial communities, a pattern presumably rooted in their distinct diets. Larvae and adult butterflies host relatively small and similar numbers of bacterial phylotypes, but few are common to both stages. The larval microbiota clearly simplifies and reorganizes during metamorphosis; thus, structural changes in a butterfly's bacterial community parallel those in its own morphology. We furthermore identify specific bacterial taxa that may mediate larval and adult feeding biology in Heliconius and other butterflies. Although male and female Heliconius adults differ in reproductive physiology and degree of pollen feeding, bacterial communities associated with H. erato are not sexually dimorphic. Lastly, we show that captive and wild individuals host different microbiota, a finding that may have important implications for the relevance of experimental studies using captive butterflies.

  6. Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction

    OpenAIRE

    Kang, In Jeong; Kang, Mi-Hyung; Noh, Tae-Hwan; Shim, Hyeong Kwon; Shin, Dong Bum; Heu, Suggi

    2016-01-01

    Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the 63°C as an opti...

  7. Postviral Complications: Bacterial Pneumonia.

    Science.gov (United States)

    Prasso, Jason E; Deng, Jane C

    2017-03-01

    Secondary bacterial pneumonia after viral respiratory infection remains a significant source of morbidity and mortality. Susceptibility is mediated by a variety of viral and bacterial factors, and complex interactions with the host immune system. Prevention and treatment strategies are limited to influenza vaccination and antibiotics/antivirals respectively. Novel approaches to identifying the individuals with influenza who are at increased risk for secondary bacterial pneumonias are urgently needed. Given the threat of further pandemics and the heightened prevalence of these viruses, more research into the immunologic mechanisms of this disease is warranted with the hope of discovering new potential therapies. Published by Elsevier Inc.

  8. Leveraging multiple datasets for deep leaf counting

    OpenAIRE

    Dobrescu, Andrei; Giuffrida, Mario Valerio; Tsaftaris, Sotirios A

    2017-01-01

    The number of leaves a plant has is one of the key traits (phenotypes) describing its development and growth. Here, we propose an automated, deep learning based approach for counting leaves in model rosette plants. While state-of-the-art results on leaf counting with deep learning methods have recently been reported, they obtain the count as a result of leaf segmentation and thus require per-leaf (instance) segmentation to train the models (a rather strong annotation). Instead, our method tre...

  9. Cutaneous manifestations of spotted fever rickettsial infections in the Central Province of Sri Lanka: a descriptive study.

    Directory of Open Access Journals (Sweden)

    Kosala Weerakoon

    2014-09-01

    Full Text Available Characteristic skin lesions play a key role in clinical diagnosis of spotted fever group rickettsioses and this study describes these cutaneous manifestations along with basic histological features.Study was conducted at Medical Unit, Teaching Hospital, Peradeniya, from November 2009 to October 2011, where a prospective data base of all rickettsial infections is maintained. Confirmation of diagnosis was made when IgM and IgG immunofluorescent antibody titre of 1/32 and >1/256 respectively. Of the 210 clinical cases, 134 had cutoff antibody titers for Rickettsia conorii antigen for confirmation. All these 134 patients had fever and skin rash, and of them 132(98% had discrete maculopapular rash while eight (6% had fern leaf type skin necrosis. Eight patients (6% had healed tick bite marks. Average size of a skin lesion was 5 mm and rash involved 52% of body surface, distributed mainly in limbs and back of the chest. Generally the facial and leg skin was slightly oedematous particularly in old aged patients. Sixteen patients (12% had pain and swelling of ankle joints where swelling extended to feet and leg. Biopsies from skin rash of six patients showed evidence of cutaneous vasculitis and of them, 247 bp region of the 17-kDa spotted fever group specific protein antigen was amplified using PCR.A discrete maculopapular rash and occasional variations such as fern leaf shape necrosis and arthritis are found in spotted fever group. Histology found vasculitis as the pathology of these lesions.

  10. Molecular and histological characterization of age spots

    Science.gov (United States)

    Choi, Wonseon; Yin, Lanlan; Smuda, Christoph; Batzer, Jan; Hearing, Vincent J.; Kolbe, Ludger

    2016-01-01

    Age spots, also called solar lentigines and lentigo senilis, are light brown to black pigmented lesions of various sizes that typically develop in chronically sun-exposed skin. It is well known that age spots are strongly related to chronic sun exposure and are associated with photodamage and an increased risk for skin cancer, however, the mechanism(s) underlying their development remain poorly understood. We used immunohistochemical analysis and microarray analysis to investigate the processes involved in their formation, focusing on specific markers associated with the functions and proliferation of melanocytes and keratinocytes. A total of 193 genes were differentially expressed in age spots but melanocyte pigment genes were not among them. The increased expression of keratins 5 and 10, markers of basal and suprabasal keratinocytes, respectively, in age spots suggests that the increased proliferation of basal keratinocytes combined with the decreased turnover of suprabasal keratinocytes leads to the exaggerated formation of rete ridges in lesional epidermis which in turn disrupts the normal processing of melanin upwards from the basal layer. Based on our results, we propose a model for the development of age spots that explains the accumulation of melanin and the development of extensive rete ridges in those hyperpigmented lesions. PMID:27621222

  11. Plutonium spot of mixed oxide fuel, 2

    International Nuclear Information System (INIS)

    Suzuki, Yukio; Maruishi, Yoshihiro; Satoh, Masaichi; Aoki, Toshimasa; Muto, Tadashi

    1974-01-01

    In a fast reactor, the specification for the homogeneity of plutonium in plutonium-uranium mixed-oxide fuel is mainly dependent on the nuclear characteristics, whereas in a thermal reactor, on thermal characteristics. This homogeneity is measured by autoradiography as the plutonium spot size of the specimens which are arbitrarily chosen fuel pellets from a lot. Although this is a kind of random sampling, it is difficult to apply this method to conventional digital standards including JIS standards. So a special sampling inspection method was studied. First, it is assumed that the shape of plutonium spots is spherical, the size distribution is logarithmic normal, and the standard deviation is constant. Then, if standard deviation and mean spot size are given, the logarithmic normal distribution is decided unitarily, and further if the total weight of plutonium spots for a lot of pellets is known, the number of the spots (No) which does not conform to the specification can be obtained. Then, the fraction defective is defined as No devided by the number of pellets per lot. As to the lot with such fraction defective, the acceptance coefficient of the lot was obtained through calculation, in which the number of sampling, acceptable diameter limit observed and acceptable conditions were used as parameters. (Tai, I.)

  12. Extracellular synthesis of silver nanoparticles using the leaf extract of Coleus amboinicus Lour

    Energy Technology Data Exchange (ETDEWEB)

    Narayanan, Kannan Badri [Department of Biotechnology, School of Life Sciences, Pondicherry University, Kalapet, Puducherry 605014 (India); Sakthivel, Natarajan, E-mail: puns2005@gmail.com [Department of Biotechnology, School of Life Sciences, Pondicherry University, Kalapet, Puducherry 605014 (India)

    2011-10-15

    Highlights: {yields} Synthesis of AgNPs using the leaf extract of Coleus amboinicus L. was described. {yields} UV-vis absorption spectra showed the formation of isotrophic AgNPs at 437 nm in 6 h. {yields} XRD analysis showed intense peaks corresponding to fcc structure of AgNPs. {yields} HR-TEM analysis revealed the formation of stable anisotrophic and isotrophic AgNPs. -- Abstract: In the present investigation, Coleus amboinicus Lour. leaf extract-mediated green chemistry approach for the synthesis of silver nanoparticles was described. The nanoparticles were characterized by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The influence of leaf extract on the control of size and shape of silver nanoparticles is reported. Upon an increase in the concentration of leaf extract, there was a shift in the shape of nanoparticles from anisotrophic nanostructures like triangle, decahedral and hexagonal to isotrophic spherical nanoparticles. Crystalline nature of fcc structured nanoparticles was confirmed by XRD spectrum with peaks corresponding to (1 1 1), (2 0 0), (2 2 0) and (3 1 1) planes and bright circular spots in the selected-area electron diffraction (SAED). Such environment friendly and sustainable methods are non-toxic, cheap and alternative to hazardous chemical procedures.

  13. Leaf sequencing algorithms for segmented multileaf collimation

    International Nuclear Information System (INIS)

    Kamath, Srijit; Sahni, Sartaj; Li, Jonathan; Palta, Jatinder; Ranka, Sanjay

    2003-01-01

    The delivery of intensity-modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation delivery. It is imperative that the fluence map delivered using the leaf sequence file is as close as possible to the fluence map generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. Optimization of the leaf sequencing algorithm has been the subject of several recent investigations. In this work, we present a systematic study of the optimization of leaf sequencing algorithms for segmental multileaf collimator beam delivery and provide rigorous mathematical proofs of optimized leaf sequence settings in terms of monitor unit (MU) efficiency under most common leaf movement constraints that include minimum leaf separation constraint and leaf interdigitation constraint. Our analytical analysis shows that leaf sequencing based on unidirectional movement of the MLC leaves is as MU efficient as bidirectional movement of the MLC leaves

  14. Leaf sequencing algorithms for segmented multileaf collimation

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, Srijit [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States); Sahni, Sartaj [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States); Li, Jonathan [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Palta, Jatinder [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Ranka, Sanjay [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States)

    2003-02-07

    The delivery of intensity-modulated radiation therapy (IMRT) with a multileaf collimator (MLC) requires the conversion of a radiation fluence map into a leaf sequence file that controls the movement of the MLC during radiation delivery. It is imperative that the fluence map delivered using the leaf sequence file is as close as possible to the fluence map generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. Optimization of the leaf sequencing algorithm has been the subject of several recent investigations. In this work, we present a systematic study of the optimization of leaf sequencing algorithms for segmental multileaf collimator beam delivery and provide rigorous mathematical proofs of optimized leaf sequence settings in terms of monitor unit (MU) efficiency under most common leaf movement constraints that include minimum leaf separation constraint and leaf interdigitation constraint. Our analytical analysis shows that leaf sequencing based on unidirectional movement of the MLC leaves is as MU efficient as bidirectional movement of the MLC leaves.

  15. Bacterial vaginosis - aftercare

    Science.gov (United States)

    Bacterial vaginosis (BV) is a type of vaginal infection. The vagina normally contains both healthy bacteria and unhealthy bacteria. BV occurs when more unhealthy bacteria grow than healthy bacteria. No one knows ...

  16. 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.

  17. 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...

  18. Diagnosis of bacterial infection

    African Journals Online (AJOL)

    direct or indirect evidence of a compatible bacterial pathogen. Inflammation may be .... cardinal features (fever, confusion, headache and neck stiffness). .... specificity, inappropriate indications or poor sampling technique may diminish this ...

  19. Effect of Addition of Moringa Leaf By-Product (Leaf-Waste) on ...

    African Journals Online (AJOL)

    The effects of incorporation of Moringa leaf fibre (a by-product of leaf processing which contains 24% Crude Fibre by dry weight at 0, 5 and 10 % substitution of wheat flour in cookies was investigated. Three products containing wheat flour: Moringa leaf fibre ratios of 100:0, 95:5, and 90:10 respectively were prepared, and a ...

  20. Specific leaf area estimation from leaf and canopy reflectance through optimization and validation of vegetation indices

    NARCIS (Netherlands)

    Ali, A.M.; Darvishzadeh, R.; Skidmore, A.K.; van Duren, I.C.

    2017-01-01

    Specific leaf area (SLA), which is defined as the leaf area per unit of dry leaf mass is an important component when assessing functional diversity and plays a key role in ecosystem modeling, linking plant carbon and water cycles as well as quantifying plant physiological processes. However, studies

  1. Leaf size and leaf display of thirty-eight tropical tree species

    NARCIS (Netherlands)

    Poorter, L.; Rozendaal, D.M.A.

    2008-01-01

    Trees forage for light through optimal leaf display. Effective leaf display is determined by metamer traits (i.e., the internode, petiole, and corresponding leaf), and thus these traits strongly co-determine carbon gain and as a result competitive advantage in a light-limited environment. We

  2. Spots on AG Virginis - paradigm or panacea?

    International Nuclear Information System (INIS)

    Bell, S.A.; Rainger, P.P.; Hilditch, R.W.

    1990-01-01

    New photometric and spectroscopic observations of the eclipsing binary AG Vir are presented. Medium-resolution spectroscopy has allowed the measurement of velocities for the secondary component for the first time. The V light curve shows many of the features seen in previous studies of this system. A full analysis of the spectroscopic and photometric data has been made which suggests that the system is either in a marginal state of contact or a deep-contact configuration depending on the type of spot model invoked. AG Vir constitutes an excellent example of the expected manifestations of spot activity on a light curve. It also demonstrates the ease with which the spot phenomenon can be invoked to explain the appearance of a light curve and to provide conflicting results. (author)

  3. How much extra spot gas is there?

    International Nuclear Information System (INIS)

    Bros, Th.

    2007-01-01

    With the increase of European gas demand and the sharp decrease of local supply, security of supply is becoming an ever greater issue. However, liberalization tilts the traditional equilibrium based on long term 'take or pay' contracts between big suppliers and national distribution companies. Today, buying gas on the spot market is becoming more and more important to balance supply portfolio with a fast moving market share. But the way gas spot markets are operating is not well documented. It is very difficult to assess its impact on the European security of supply. Therefore, the aim of this article is to evaluate the amount of 'spot' liquefied natural gas (LNG) that could be found in case of a major supply disruption in pipe gas delivered to Europe

  4. Laser Spot Center Detection and Comparison Test

    Science.gov (United States)

    Zhu, Jun; Xu, Zhengjie; Fu, Deli; Hu, Cong

    2018-04-01

    High efficiency and precision of the pot center detection are the foundations of avionics instrument navigation and optics measurement basis for many applications. It has noticeable impact on overall system performance. Among them, laser spot detection is very important in the optical measurement technology. In order to improve the low accuracy of the spot center position, the algorithm is improved on the basis of the circle fitting. The pretreatment is used by circle fitting, and the improved adaptive denoising filter for TV repair technology can effectively improves the accuracy of the spot center position. At the same time, the pretreatment and de-noising can effectively reduce the influence of Gaussian white noise, which enhances the anti-jamming capability.

  5. PREDICTING RELEVANT EMPTY SPOTS IN SOCIAL INTERACTION

    Institute of Scientific and Technical Information of China (English)

    Yoshiharu MAENO; Yukio OHSAWA

    2008-01-01

    An empty spot refers to an empty hard-to-fill space which can be found in the records of the social interaction, and is the clue to the persons in the underlying social network who do not appear in the records. This contribution addresses a problem to predict relevant empty spots in social interaction. Homogeneous and inhomogeneous networks are studied as a model underlying the social interaction. A heuristic predictor function method is presented as a new method to address the problem. Simulation experiment is demonstrated over a homogeneous network. A test data set in the form of market baskets is generated from the simulated communication. Precision to predict the empty spots is calculated to demonstrate the performance of the presented method.

  6. [Rocky Mountain spotted fever in Brazil].

    Science.gov (United States)

    del Sá DelFiol, Fernando; Junqueira, Fábio Miranda; da Rocha, Maria Carolina Pereira; de Toledo, Maria Inês; Filho, Silvio Barberato

    2010-06-01

    Although the number of confirmed cases of spotted fever has been declining in Brazil since 2005, the mortality rate (20% to 30%) is still high in comparison to other countries. This high mortality rate is closely related to the difficulty in making the diagnosis and starting the correct treatment. Only two groups of antibiotics have proven clinical effectiveness against spotted fever: chloramphenicol and tetracyclines. Until recently, the use of tetracyclines was restricted to adults because of the associated bone and tooth changes in children. Recently, however, the American Academy of Pediatrics and various researchers have recommended the use of doxycycline in children. In more severe cases, chloramphenicol injections are often preferred in Brazil because of the lack of experience with injectable tetracycline. Since early diagnosis and the adequate drug treatment are key to a good prognosis, health care professionals must be better prepared to recognize and treat spotted fever.

  7. Protein profile of Beta vulgaris leaf apoplastic fluid and changes induced by Fe deficiency and Fe resupply

    Directory of Open Access Journals (Sweden)

    Laura eCeballos-Laita

    2015-03-01

    Full Text Available The fluid collected by direct leaf centrifugation has been used to study the proteome of the sugar beet apoplastic fluid as well as the changes induced by Fe deficiency and Fe resupply to Fe-deficient plants in the protein profile. Plants were grown in Fe-sufficient and Fe-deficient conditions, and Fe resupply was carried out with 45 μM Fe(III-EDTA for 24 h. Protein extracts of leaf apoplastic fluid were analyzed by two-dimensional isoelectric focusing-SDS-PAGE electrophoresis. Gel image analysis revealed 203 consistent spots, and proteins in 81% of them (164 were identified by nLC-MS/MS using a custom made reference repository of beet protein sequences. When redundant UniProt entries were deleted, a non-redundant leaf apoplastic proteome consisting of 109 proteins was obtained. TargetP and SecretomeP algorithms predicted that 63% of them were secretory proteins. Functional classification of the non-redundant proteins indicated that stress and defense, protein metabolism, cell wall and C metabolism accounted for approximately 75% of the identified proteome. The effects of Fe-deficiency on the leaf apoplast proteome were limited, with only five spots (2.5% changing in relative abundance, thus suggesting that protein homeostasis in the leaf apoplast fluid is well maintained upon Fe shortage. The identification of three chitinase isoforms among proteins increasing in relative abundance with Fe-deficiency suggests that one of the few effects of Fe deficiency in the leaf apoplast proteome includes cell wall modifications. Iron resupply to Fe deficient plants changed the relative abundance of 16 spots when compared to either Fe-sufficient or Fe-deficient samples. Proteins identified in these spots can be broadly classified as those responding to Fe-resupply, which included defense and cell wall related proteins, and non-responsive, which are mainly protein metabolism related proteins and whose changes in relative abundance followed the same trend as

  8. Volume dips; spot price ranges narrow

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    This article is the September 1994 uranium market summary. Volume in the spot concentrates market fell below 1 million lbs U3O8. In total, twelve deals took place compared to 28 deals in August. Of the twelve deals, three took place in the spot concentrates market, two took place in the medium and long-term market, three in the conversion market, and four in the enrichment market. Restricted prices weakened, but unrestricted prices firmed slightly. The enrichment price range narrowed a bit

  9. Sweet Spot Supersymmetry and Composite Messengers

    International Nuclear Information System (INIS)

    Ibe, Masahiro; Kitano, Ryuichiro

    2007-01-01

    Sweet spot supersymmetry is a phenomenologically and cosmologically perfect framework to realize a supersymmetric world at short distance. We discuss a class of dynamical models of supersymmetry breaking and its mediation whose low-energy effective description falls into this framework. Hadron fields in the dynamical models play a role of the messengers of the supersymmetry breaking. As is always true in the models of the sweet spot supersymmetry, the messenger scale is predicted to be 10 5 GeV ∼ mess ∼ 10 GeV. Various values of the effective number of messenger fields N mess are possible depending on the choice of the gauge group

  10. Observations spotted solar type stars in Pleiades

    International Nuclear Information System (INIS)

    Magnitskij, A.K.

    1987-01-01

    The september - october 1986 observations discovered periodic light variations in three solar type stars in the Pleiades cluster: Hz 296 (0.8 M Sun ), Hz152(0.91 M Sun ) and Hz739(1.15 M Sun ). Periods and amplitudes are accordingly 2 d and 0 m .11, 4 d .12 and 0 m .07, 2 d .70 and 0 m .05. Considerable light variations of these stars in Pleiades are due to the rotation of spotted stars. Contrast spots of solar type stars likely exist when stars are young and rapidly rotate

  11. Detection of food-borne bacteria in ready to eat betel leaf sold at local markets in Mymensingh.

    Science.gov (United States)

    Haque, Md Mazedul; Sarker, Md Atiqur Rahman; Rifa, Rafia Afroze; Islam, Md Ariful; Khatun, Mst Minara

    2017-09-01

    The present study was undertaken to determine bacterial load as well as characterize bacterial flora of ready to eat (RTE) betel leaf sold at local markets in Mymensingh city. A total of 25 RTE betel leaf samples were collected from five local markets such as Kamal-Ranjit (KR) market, Shesh more, Kewatkhali, Jobber more, and Ganginar par. Total viable count of bacteria in betel leaf (log 10 mean colony forming unit±standard deviation/ml) was 7.58±0.04 for KR market, 7.72±0.06 for Shesh more, 7.62±0.04 for Kewatkhali, 7.40±0.03 for Jobber more, and 7.60±0.06 for Ganginar par. A total of 98 bacterial isolates belong to five genera ( Escherichia coli , Salmonella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp.) were identified. The prevalence of E. coli was 17.34%, Salmonella spp. was 25.51%, Vibrio spp. was 19.39%, Bacillus spp. was 18.37%, and Staphylococcus spp. was 19.39%. Antibiotic sensitivity test showed that all isolates were sensitive to two antibiotics such as ciprofloxacin and gentamicin. Four isolates ( E. coli , Salmonella spp., Vibrio spp., and Staphylococcus spp.) were resistant to two antibiotics (ampicillin and cephalexin). Antibiogram profile of bacterial isolates of betel leaf suggests that they were multidrug resistance. Data of this study indicate that betel leaf sold at local market harbors multidrug resistance food-borne bacteria which might cause public health hazards if these antibiotic resistant transfer to human through food chain.

  12. Detection of food-borne bacteria in ready to eat betel leaf sold at local markets in Mymensingh

    Directory of Open Access Journals (Sweden)

    Md. Mazedul Haque

    2017-09-01

    Full Text Available Aim: The present study was undertaken to determine bacterial load as well as characterize bacterial flora of ready to eat (RTE betel leaf sold at local markets in Mymensingh city. Materials and Methods: A total of 25 RTE betel leaf samples were collected from five local markets such as Kamal-Ranjit (KR market, Shesh more, Kewatkhali, Jobber more, and Ganginar par. Results: Total viable count of bacteria in betel leaf (log10 mean colony forming unit±standard deviation/ml was 7.58±0.04 for KR market, 7.72±0.06 for Shesh more, 7.62±0.04 for Kewatkhali, 7.40±0.03 for Jobber more, and 7.60±0.06 for Ganginar par. A total of 98 bacterial isolates belong to five genera (Escherichia coli, Salmonella spp., Vibrio spp., Bacillus spp., and Staphylococcus spp. were identified. The prevalence of E. coli was 17.34%, Salmonella spp. was 25.51%, Vibrio spp. was 19.39%, Bacillus spp. was 18.37%, and Staphylococcus spp. was 19.39%. Antibiotic sensitivity test showed that all isolates were sensitive to two antibiotics such as ciprofloxacin and gentamicin. Four isolates (E. coli, Salmonella spp., Vibrio spp., and Staphylococcus spp. were resistant to two antibiotics (ampicillin and cephalexin. Antibiogram profile of bacterial isolates of betel leaf suggests that they were multidrug resistance. Conclusion: Data of this study indicate that betel leaf sold at local market harbors multidrug resistance food-borne bacteria which might cause public health hazards if these antibiotic resistant transfer to human through food chain.

  13. "Breath figures" on leaf surfaces-formation and effects of microscopic leaf wetness.

    Science.gov (United States)

    Burkhardt, Juergen; Hunsche, Mauricio

    2013-01-01

    "Microscopic leaf wetness" means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 μm, microscopic leaf wetness is about two orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the type and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g., ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  14. ‘Breath figures’ on leaf surfaces – formation and effects of microscopic leaf wetness

    Directory of Open Access Journals (Sweden)

    Jürgen eBurkhardt

    2013-10-01

    Full Text Available ‘Microscopic leaf wetness’ means minute amounts of persistent liquid water on leaf surfaces which are invisible to the naked eye. The water is mainly maintained by transpired water vapor condensing onto the leaf surface and to attached leaf surface particles. With an estimated average thickness of less than 1 µm, microscopic leaf wetness it is about 2 orders of magnitude thinner than morning dewfall. The most important physical processes which reduce the saturation vapor pressure and promote condensation are cuticular absorption and the deliquescence of hygroscopic leaf surface particles. Deliquescent salts form highly concentrated solutions. Depending on the amount and concentration of the dissolved ions, the physicochemical properties of microscopic leaf wetness can be considerably different from those of pure water. Microscopic leaf wetness can form continuous thin layers on hydrophobic leaf surfaces and in specific cases can act similar to surfactants, enabling a strong potential influence on the foliar exchange of ions. Microscopic leaf wetness can also enhance the dissolution, the emission, and the reaction of specific atmospheric trace gases e.g. ammonia, SO2, or ozone, leading to a strong potential role for microscopic leaf wetness in plant/atmosphere interaction. Due to its difficult detection, there is little knowledge about the occurrence and the properties of microscopic leaf wetness. However, based on the existing evidence and on physicochemical reasoning it can be hypothesized that microscopic leaf wetness occurs on almost any plant worldwide and often permanently, and that it significantly influences the exchange processes of the leaf surface with its neighboring compartments, i.e., the plant interior and the atmosphere. The omission of microscopic water in general leaf wetness concepts has caused far-reaching, misleading conclusions in the past.

  15. Newborn screening blood spot analysis in the UK: influence of spot size, punch location and haematocrit.

    Science.gov (United States)

    Lawson, A J; Bernstone, L; Hall, S K

    2016-03-01

    In dried blood spot analysis, punch location and variations in applied sample volume and haematocrit can produce different measured concentrations of analytes. We investigated the magnitude of these effects in newborn screening in the UK. Heparinized blood spiked with thyroid stimulating hormone (TSH), phenylalanine, tyrosine, leucine, methionine, octanoyl carnitine (C8), and immunoreactive trypsinogen (IRT) was spotted onto filter paper: (i) at a constant haematocrit of 50% at various volumes, and (ii) at a range of haematocrits using a constant volume. Subpunches (3.2 mm) of the dried blood spots were then analysed. Compared with a central punch from a 50 µL blood spot with 50% haematocrit, 10 µL spots can have significantly lower measured concentrations of all analytes, with decreases of 15% or more observed for leucine, methionine, phenylalanine, and tyrosine. Punching at the edge of a spot can increase measured concentrations up to 35%. Higher haematocrit decreased measured TSH and C8 yet increased amino acids and IRT by 15% compared with 50% haematocrit. Lower haematocrits had the opposite effect, but only with higher concentrations of some analytes. Differences in blood spot size, haematocrit and punch location substantially affect measured concentrations for analytes used in the UK newborn screening programme, and this could affect false positive and negative rates. To minimize analytical bias, these variables should be controlled or adjusted for where possible. © The Author(s) 2015.

  16. Effective onion leaf fleck management and variability of storage pathogens

    Directory of Open Access Journals (Sweden)

    Rasiukevičiūtė Neringa

    2016-01-01

    Full Text Available Botrytis spp. cause several diseases in Allium crops and depending on meteorological conditions economic losses can exceed 50%. Forecasting models improve plant protection and sometimes reduce consumption of fungicides, because applications are made precisely during the favourable periods for disease development. Our aim was to evaluate the iMETOS®sm B. cinerea forecasting model as an effective onion leaf fleck management system and estimate the variability of onion bulb pathogens during storage. Assessment of forecasting model data showed that favourable conditions for leaf fleck development arise in July, but greatly depend on that year’s meteorological conditions. During an experimental year the first sprayings with fungicides were applied as forecasted from the model, which resulted in application 19, 6 and 23 days earlier than conventional treatment application times. In 2012-2014 iMETOS®sm treatment yield increased by 3.51 t ha-1, 3.87 t ha-1 and3.40 t ha-1 relative to the control. During storage most frequent injuries were fungal (44% and bacterial (41%, followed by insects (7% and physiological (9%. The highest prevalence of injuries was detected after 2 months of storage.

  17. Transitional–turbulent spots and turbulent–turbulent spots in boundary layers

    Science.gov (United States)

    Wu, Xiaohua; Moin, Parviz; Wallace, James M.; Skarda, Jinhie; Lozano-Durán, Adrián; Hickey, Jean-Pierre

    2017-01-01

    Two observations drawn from a thoroughly validated direct numerical simulation of the canonical spatially developing, zero-pressure gradient, smooth, flat-plate boundary layer are presented here. The first is that, for bypass transition in the narrow sense defined herein, we found that the transitional–turbulent spot inception mechanism is analogous to the secondary instability of boundary-layer natural transition, namely a spanwise vortex filament becomes a Λ vortex and then, a hairpin packet. Long streak meandering does occur but usually when a streak is infected by a nearby existing transitional–turbulent spot. Streak waviness and breakdown are, therefore, not the mechanisms for the inception of transitional–turbulent spots found here. Rather, they only facilitate the growth and spreading of existing transitional–turbulent spots. The second observation is the discovery, in the inner layer of the developed turbulent boundary layer, of what we call turbulent–turbulent spots. These turbulent–turbulent spots are dense concentrations of small-scale vortices with high swirling strength originating from hairpin packets. Although structurally quite similar to the transitional–turbulent spots, these turbulent–turbulent spots are generated locally in the fully turbulent environment, and they are persistent with a systematic variation of detection threshold level. They exert indentation, segmentation, and termination on the viscous sublayer streaks, and they coincide with local concentrations of high levels of Reynolds shear stress, enstrophy, and temperature fluctuations. The sublayer streaks seem to be passive and are often simply the rims of the indentation pockets arising from the turbulent–turbulent spots. PMID:28630304

  18. Transitional-turbulent spots and turbulent-turbulent spots in boundary layers.

    Science.gov (United States)

    Wu, Xiaohua; Moin, Parviz; Wallace, James M; Skarda, Jinhie; Lozano-Durán, Adrián; Hickey, Jean-Pierre

    2017-07-03

    Two observations drawn from a thoroughly validated direct numerical simulation of the canonical spatially developing, zero-pressure gradient, smooth, flat-plate boundary layer are presented here. The first is that, for bypass transition in the narrow sense defined herein, we found that the transitional-turbulent spot inception mechanism is analogous to the secondary instability of boundary-layer natural transition, namely a spanwise vortex filament becomes a [Formula: see text] vortex and then, a hairpin packet. Long streak meandering does occur but usually when a streak is infected by a nearby existing transitional-turbulent spot. Streak waviness and breakdown are, therefore, not the mechanisms for the inception of transitional-turbulent spots found here. Rather, they only facilitate the growth and spreading of existing transitional-turbulent spots. The second observation is the discovery, in the inner layer of the developed turbulent boundary layer, of what we call turbulent-turbulent spots. These turbulent-turbulent spots are dense concentrations of small-scale vortices with high swirling strength originating from hairpin packets. Although structurally quite similar to the transitional-turbulent spots, these turbulent-turbulent spots are generated locally in the fully turbulent environment, and they are persistent with a systematic variation of detection threshold level. They exert indentation, segmentation, and termination on the viscous sublayer streaks, and they coincide with local concentrations of high levels of Reynolds shear stress, enstrophy, and temperature fluctuations. The sublayer streaks seem to be passive and are often simply the rims of the indentation pockets arising from the turbulent-turbulent spots.

  19. Leaf Wetness within a Lily Canopy

    NARCIS (Netherlands)

    Jacobs, A.F.G.; Heusinkveld, B.G.; Klok, E.J.

    2005-01-01

    A wetness duration experiment was carried out within a lily field situated adjacent to coastal dunes in the Netherlands. A within-canopy model was applied to simulate leaf wetness in three layers, with equal leaf area indices, within the canopy. This simulation model is an extension of an existing

  20. 7 CFR 29.3528 - Leaf surface.

    Science.gov (United States)

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign Type 95) § 29.3528 Leaf surface. The roughness or smoothness of the web or lamina of a tobacco leaf...

  1. Estimation of leaf area in tropical maize

    NARCIS (Netherlands)

    Elings, A.

    2000-01-01

    Leaf area development of six tropical maize cultivars grown in 1995 and 1996 in several tropical environments in Mexico (both favourable and moisture-and N-limited) was observed and analysed. First, the validity of a bell-shaped curve describing the area of individual leaves as a function of leaf

  2. Chromosome-damaging effect of betel leaf.

    Science.gov (United States)

    Sadasivan, G; Rani, G; Kumari, C K

    1978-05-01

    The chewing of betel leaf with other ingredients is a widespread addiction in India. The chromosome damaging effect was studied in human leukocyte cultures. There was an increase in the frequency of chromatid aberrations when the leaf extract was added to cultures.

  3. ANXIOLYTIC ACTIVITY OF OCIMUM SANCTUM LEAF EXTRACT

    OpenAIRE

    Chattopadhyay, R.R.

    1994-01-01

    The anxiolytic activity of Ocimum sanctum leaf extract was studied in mice. O.sanctum leaf extract produced significant anxiolytic activity in plus – maze and open field behaviour test models. The effect was compared with diazepam, a standard antianxiety drug.

  4. 7 CFR 29.2530 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.2530 Section 29.2530 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2530 Leaf structure. The cell development of...

  5. 7 CFR 29.2278 - Leaf structure.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf structure. 29.2278 Section 29.2278 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... structure. The cell development of a leaf as indicated by its porosity. (See chart, § 29.2351.) ...

  6. 7 CFR 29.2277 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2277 Section 29.2277 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists...

  7. 7 CFR 29.2529 - Leaf scrap.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

  8. Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy.

    Science.gov (United States)

    Morel, Paul; Wu, Xiaodong; Blin, Guillaume; Vialette, Stéphane; Flynn, Ryan; Hyer, Daniel; Wang, Dongxu

    2015-01-01

    This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. The method proposed in this study adapts the weight (MU) of the delivering pencil beam to that of the target spot; it will actually hit during patient/target motion. The target spot that a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D) CT. After the adapted delivery, the required total weight [Monitor Unit (MU)] for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated. For moderate motion (i.e., mean amplitude 0.5 cm), D95% to the planning target volume (PTV) was only 81.5% of the prescription (RX) dose; with spot weight adaptation PTV D95% achieves 97.7% RX. For large motion amplitude (i.e., 1.5 cm), without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7% RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3 mm or smaller in patient/target position tracking is preferred. The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

  9. Spot Weight Adaptation for Moving Target in Spot Scanning Proton Therapy

    Directory of Open Access Journals (Sweden)

    Paul eMorel

    2015-05-01

    Full Text Available Purpose: This study describes a real-time spot weight adaptation method in spot-scanning proton therapy for moving target or moving patient, so that the resultant dose distribution closely matches the planned dose distribution. Materials and Methods: The method proposed in this study adapts the weight (MU of the delivering pencil beam to that of the target spot it will actually hit during patient/target motion. The target spot a certain delivering pencil beam may hit relies on patient monitoring and/or motion modeling using four-dimensional (4D CT. After the adapted delivery, the required total weight (MU for this target spot is then subtracted from the planned value. With continuous patient motion and continuous spot scanning, the planned doses to all target spots will eventually be all fulfilled. In a proof-of-principle test, a lung case was presented with realistic temporal and motion parameters; the resultant dose distribution using spot weight adaptation was compared to that without using this method. The impact of the real-time patient/target position tracking or prediction was also investigated.Results: For moderate motion (i.e., mean amplitude 0.5 cm, D95% to the planning target volume (PTV was only 81.5% of the prescription (RX dose; with spot weight adaptation PTV D95% achieves 97.7%RX. For large motion amplitude (i.e., 1.5 cm, without spot weight adaptation PTV D95% is only 42.9% of RX; with spot weight adaptation, PTV D95% achieves 97.7%RX. Larger errors in patient/target position tracking or prediction led to worse final target coverage; an error of 3mm or smaller in patient/target position tracking is preferred. Conclusion: The proposed spot weight adaptation method was able to deliver the planned dose distribution and maintain target coverage when patient motion was involved. The successful implementation of this method would rely on accurate monitoring or prediction of patient/target motion.

  10. Easy Leaf Area: Automated digital image analysis for rapid and accurate measurement of leaf area.

    Science.gov (United States)

    Easlon, Hsien Ming; Bloom, Arnold J

    2014-07-01

    Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. • Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. • Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

  11. Easy Leaf Area: Automated Digital Image Analysis for Rapid and Accurate Measurement of Leaf Area

    Directory of Open Access Journals (Sweden)

    Hsien Ming Easlon

    2014-07-01

    Full Text Available Premise of the study: Measurement of leaf areas from digital photographs has traditionally required significant user input unless backgrounds are carefully masked. Easy Leaf Area was developed to batch process hundreds of Arabidopsis rosette images in minutes, removing background artifacts and saving results to a spreadsheet-ready CSV file. Methods and Results: Easy Leaf Area uses the color ratios of each pixel to distinguish leaves and calibration areas from their background and compares leaf pixel counts to a red calibration area to eliminate the need for camera distance calculations or manual ruler scale measurement that other software methods typically require. Leaf areas estimated by this software from images taken with a camera phone were more accurate than ImageJ estimates from flatbed scanner images. Conclusions: Easy Leaf Area provides an easy-to-use method for rapid measurement of leaf area and nondestructive estimation of canopy area from digital images.

  12. Possible Roles of Strigolactones during Leaf Senescence

    Directory of Open Access Journals (Sweden)

    Yusuke Yamada

    2015-09-01

    Full Text Available Leaf senescence is a complicated developmental process that involves degenerative changes and nutrient recycling. The progress of leaf senescence is controlled by various environmental cues and plant hormones, including ethylene, jasmonic acid, salicylic acid, abscisic acid, cytokinins, and strigolactones. The production of strigolactones is induced in response to nitrogen and phosphorous deficiency. Strigolactones also accelerate leaf senescence and regulate shoot branching and root architecture. Leaf senescence is actively promoted in a nutrient-poor soil environment, and nutrients are transported from old leaves to young tissues and seeds. Strigolactones might act as important signals in response to nutrient levels in the rhizosphere. In this review, we discuss the possible roles of strigolactones during leaf senescence.

  13. Sustainable control of white spot disease

    DEFF Research Database (Denmark)

    Heinecke, Rasmus Demuth; Buchmann, Kurt

    White spot disease caused by the ciliate Ichthyophthirius multifiliis Fouquet, 1876 is a serious problem in freshwater aquaculture worldwide. This parasitosis is of frequent occurrence in both conventional earth pond fish farms and in fish farms using new high technology re-circulation systems...

  14. Dramatic Change in Jupiter's Great Red Spot

    Science.gov (United States)

    Simon, A. A.; Wong, M. H.; Rogers, J. H.; Orton, G. S.; de Pater, I.; Asay-Davis, X.; Carlson, R. W.; Marcus, P. S.

    2015-01-01

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features, having been continuously observed since the 1800's. It currently spans the smallest latitude and longitude size ever recorded. Here we show analyses of 2014 Hubble spectral imaging data to study the color, structure and internal dynamics of this long-live storm.

  15. Easy Demonstration of the Poisson Spot

    Science.gov (United States)

    Gluck, Paul

    2010-01-01

    Many physics teachers have a set of slides of single, double and multiple slits to show their students the phenomena of interference and diffraction. Thomas Young's historic experiments with double slits were indeed a milestone in proving the wave nature of light. But another experiment, namely the Poisson spot, was also important historically and…

  16. Triggered tremor sweet spots in Alaska

    Science.gov (United States)

    Gomberg, Joan; Prejean, Stephanie

    2013-01-01

    To better understand what controls fault slip along plate boundaries, we have exploited the abundance of seismic and geodetic data available from the richly varied tectonic environments composing Alaska. A search for tremor triggered by 11 large earthquakes throughout all of seismically monitored Alaska reveals two tremor “sweet spots”—regions where large-amplitude seismic waves repeatedly triggered tremor between 2006 and 2012. The two sweet spots locate in very different tectonic environments—one just trenchward and between the Aleutian islands of Unalaska and Akutan and the other in central mainland Alaska. The Unalaska/Akutan spot corroborates previous evidence that the region is ripe for tremor, perhaps because it is located where plate-interface frictional properties transition between stick-slip and stably sliding in both the dip direction and laterally. The mainland sweet spot coincides with a region of complex and uncertain plate interactions, and where no slow slip events or major crustal faults have been noted previously. Analyses showed that larger triggering wave amplitudes, and perhaps lower frequencies (tremor. However, neither the maximum amplitude in the time domain or in a particular frequency band, nor the geometric relationship of the wavefield to the tremor source faults alone ensures a high probability of triggering. Triggered tremor at the two sweet spots also does not occur during slow slip events visually detectable in GPS data, although slow slip below the detection threshold may have facilitated tremor triggering.

  17. Electricity spot price dynamics: Beyond financial models

    International Nuclear Information System (INIS)

    Guthrie, Graeme; Videbeck, Steen

    2007-01-01

    We reveal properties of electricity spot prices that cannot be captured by the statistical models, commonly used to model financial asset prices, that are increasingly used to model electricity prices. Using more than eight years of half-hourly spot price data from the New Zealand Electricity Market, we find that the half-hourly trading periods fall naturally into five groups corresponding to the overnight off-peak, the morning peak, daytime off-peak, evening peak, and evening off-peak. The prices in different trading periods within each group are highly correlated with each other, yet the correlations between prices in different groups are lower. Models, adopted from the modeling of security prices, that are currently applied to electricity spot prices are incapable of capturing this behavior. We use a periodic autoregression to model prices instead, showing that shocks in the peak periods are larger and less persistent than those in off-peak periods, and that they often reappear in the following peak period. In contrast, shocks in the off-peak periods are smaller, more persistent, and die out (perhaps temporarily) during the peak periods. Current approaches to modeling spot prices cannot capture this behavior either. (author)

  18. Matching Two-dimensional Gel Electrophoresis' Spots

    DEFF Research Database (Denmark)

    Dos Anjos, António; AL-Tam, Faroq; Shahbazkia, Hamid Reza

    2012-01-01

    This paper describes an approach for matching Two-Dimensional Electrophoresis (2-DE) gels' spots, involving the use of image registration. The number of false positive matches produced by the proposed approach is small, when compared to academic and commercial state-of-the-art approaches. This ar...

  19. Rocky Mountain spotted fever in dogs, Brazil.

    Science.gov (United States)

    Labruna, Marcelo B; Kamakura, Orson; Moraes-Filho, Jonas; Horta, Mauricio C; Pacheco, Richard C

    2009-03-01

    Clinical illness caused by Rickettsia rickettsii in dogs has been reported solely in the United States. We report 2 natural clinical cases of Rocky Mountain spotted fever in dogs in Brazil. Each case was confirmed by seroconversion and molecular analysis and resolved after doxycycline therapy.

  20. The sweet spots in human communication.

    Science.gov (United States)

    Salem, Philip

    2011-07-01

    In baseball, the sweet spot is a special place on a bat where the batter can hit the ball with the most power. It is the place where the performances of the batter and pitcher collide with maximum effect. It is the place where the dynamic tension between opponents leads to transformation. The dynamic tension in all living systems is between similarity and difference. Chaos and complexity scholars recognized this tension as amounts of information. When the amounts of information were high, but not too high, the system moved to the edge of chaos, to the complexity regime, to strange attractors, or to chaos, depending on the model. The sweet spot is that range of relative variety, just the proper mix of similarity and difference, leading to transformation. This essay contains a model of human communication as an emergent social process with its own sweet spots. The essay also includes a description of current literature highlighting tensions between similarity and difference, and there is an exploration of the potential to move from one basin of attraction to another. The primary constraints on finding communication sweet spots are paradigmatic - adopting a process orientation, discovering the proper parameters, bracketing sequences to define initial conditions, and understanding the strengths and weaknesses of various modeling techniques.