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Sample records for citrus rust mite

  1. Interrelations between citrus rust mite, Hirsutella thompsonii and greasy spot on citrus in Surinam

    NARCIS (Netherlands)

    Brussel, van E.W.

    1975-01-01

    Counts of citrus rust mite (Phyllocoptruta oleivora (Ashm.)) on leaves and fruit of citrus rose to a peak in the two dry seasons, the build up taking 4-5 weeks. It then decreased partly through infection by the entomogenous fungus Hirsutellathompsonii Fisher and partly through a decline in feed qual

  2. Citrus rootstocks influence the population densities of pest mites

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    Rafael Rocha da Silva

    2016-01-01

    Full Text Available Citrus are attacked by pest mites such as the citrus rust mite Phyllocoptruta oleivora (Ashmead (Acari: Eriophyidae and the spider mite Tetranychus mexicanus (McGregor (Acari: Tetranychidae. However, little is known on citrus rootstocks influencing pest mites. We aimed to evaluate the influence of rootstocks on population densities of pest mites on the sweet oranges 'Pera CNPMF D-6' and 'Valencia Tuxpan' throughout time. Adults of both mite species were monthly counted during 19 months from June 2011 to February 2013. Rootstocks influenced the populations of pest mites, since lower densities of P. oleivora were found on 'Pera CNPMF D-6' sweet orange grafted on the hybrid TSKC × CTTR - 002 and on 'Swingle' citrumelo in comparison with the hybrid LVK × LCR - 010, 'Red' rough lime and 'Santa Cruz' rangpur lime as rootstocks. Similarly, lower densities of T. mexicanus were found on 'Valencia Tuxpan' sweet orange grafted on the hybrid HTR-051 in comparison to 'Indio' citrandarin, 'Sunki Tropical' mandarin and LVK × LCR - 010 as rootstocks. We concluded that densities of the mites P. oleivora and T. mexicanus on the sweet oranges 'Pera CNPMF D-6' and 'Valencia Tuxpan' were affected in some periods of the year by some rootstocks, suggesting influence of some genotypes on these pests.

  3. First report of the citrus Hindu mite, Schizotetranychus hindustanicus (Hirst) (Prostigmata: Tetranychidae), in Brazil.

    Science.gov (United States)

    Navia, Denise; Marsaro, Alberto L

    2010-01-01

    The citrus Hindu mite, Schizotetranychus hindustanicus (Hirst), is reported for the first time in Brazil and for the second time in South America. Mite specimens were collected from citrus in the municipality of Boa Vista, State of Roraima, northern Brazil. Symptoms associated with S.hindustanicus infestations on citrus are described. The importance of avoiding dissemination of this mite to the main citrus production areas in Brazil is discussed.

  4. Ricoseius loxocheles, a phytoseiid mite that feeds on coffee leaf rust.

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    Oliveira, Cleber M; Ferreira, João A M; Oliveira, Rafael M; Santos, Francisco O; Pallini, Angelo

    2014-10-01

    One of the most important diseases of coffee plants is the coffee leaf rust fungus Hemileia vastatrix Berkeley and Broome (Uredinales). It can cause 30 % yield loss in some varieties of Coffea arabica (L.). Besides fungus, the coffee plants are attacked by phytophagous mites. The most common species is the coffee red mite, Oligonychus ilicis McGregor (Acari: Tetranychidae). Predatory mites of the Phytoseiidae family are well-known for their potential to control herbivorous mites and insects, but they can also develop and reproduce on various other food sources, such as plant pathogenic fungi. In a field survey, we found Ricoseius loxocheles (De Leon) (Acari: Phytoseiidae) on the necrotic areas caused by the coffee leaf rust fungus during the reproductive phase of the pathogen. We therefore assessed the development, survivorship and reproduction of R. loxocheles feeding on coffee leaf rust fungus and measured predation and oviposition of this phytoseiid having coffee red mite as prey under laboratory conditions. The mite fed, survived, developed and reproduced successfully on this pathogen but it was not able to prey on O. ilicis. Survival and oviposition with only prey were the same as without food. This phytoseiid mite does not really use O. ilicis as food. It is suggested that R. loxocheles is one phytoseiid that uses fungi as a main food source.

  5. DIVERSITY AND ABUNDANCE OF MITES IN A MANDARIN CITRUS ORCHARD IN WEST SUMATRA

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    Affandi Affandi

    2016-10-01

    Full Text Available Some of the most destructive pests in citrus orchards are spider mites. Monitoring prior applied pest control is a standard procedure for integrated pest management (IPM. The study aimed to survey and determine the distribution, abundance, and diversity of phytophagous, predatory, and detritivorous mites at different stages of development of arboreal plant parts, weeds and litter in the citrus orchard. A periodical sampling survey method was conducted on six growth stages of mandarin citrus, weeds and litter of the Indonesian Fruits Research Institute experimental field in Solok, West Sumatra in December 2003 to June 2004. All mites attached on each growth stage of citrus, weeds and litter were trapped and mounted on slide for identification purposes. Identification of the mites was conducted in the Acarology Laboratory, Department of Entomology, University of the Philippines at Los Banos in July-October 2004. The results showed that a very rich mite fauna of 130 species was found in the arboreal parts of citrus crops, weeds and litter below the canopy of the citrus orchard. Among the trophic groups, detritivorous mites were the most abundant, followed by the predators, phytophages, and those unknown feeding habit. Among the habitats, weeds harbored the most mite species followed by litter and arboreal parts of the citrus trees. The flush growth stage had the least diverse mite fauna with index diversity (H’ of 1.27, while the most diverse (H’ = 2.01 was found at fruit development phase II. Result of this research was useful in determining proper time for controlling phytophagous mites. Besides, the result also provides important information on potential predatory mites that can be used as biological control agents. Furthermore, the study implies the importance of maintaining cover crops of weeds and litter beneath the citrus trees as refuge and source of alternate prey for predators which suppressed populations of phytophagous mites.

  6. New occupational allergen in citrus farmers: citrus red mite (Panonychus citri).

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    Kim, Y K; Son, J W; Kim, H Y; Park, H S; Lee, M H; Cho, S H; Min, K U; Kim, Y Y

    1999-02-01

    There have been several reports of occupational allergy to spider mites (Tetranychidae), but no published report has described citrus red mite (CRM, Panonychus citri)-induced occupational asthma confirmed by specific bronchial challenge. The purpose of this study was to evaluate clinical and immunologic characteristics of CRM-induced occupational asthma. We encountered 16 cases of CRM-induced occupational asthma among farmers cultivating citrus fruits. Asthmatic attacks corresponded closely with their work on citrus farms. The mean duration of the latent period was 12.9 (range 7 to 20) years. During their first visit to our clinic, nine patients with FEV1 lower than 70% of predictive value showed reversible airway obstruction after inhalation of bronchodilator, and seven with FEV1 greater than 70% of predictive value showed airway hyperresponsiveness to methacholine. Fifteen of the 16 also complained of recurrent nasal symptoms, which had developed at an earlier time than the asthmatic symptoms. They showed strong positive reactions to CRM extract on skin prick test (A/H ratio > or = 1.0) and had high serum specific IgE antibody against CRM which was detected by ELISA. Skin prick test with common inhalant allergens revealed that 10 had an isolated positive response to CRM with negative results to common inhalant allergens in their environment. The ELISA inhibition tests with CRM demonstrated significant inhibitions by CRM in a dose-dependent manner, while minimal inhibitions were noted by D. pteronyssinus and mugwort allergens. These findings suggest that CRM could induce IgE-mediated bronchoconstriction in exposed workers on citrus farm.

  7. New mite invasions in citrus: A look towards the early years of the twenty-first century

    Science.gov (United States)

    Several mite species commonly attack cultivated citrus around the world. About 104 phytophagous species have been reported causing different levels of damage in citrus leaves, buds and fruits, but only a dozen can be considered major pests that require control measures. During the last few years se...

  8. Survey of current crop management practices in a mixed-ricefield landscape, Mekong Delta, Vietnam - potential of habitat manipulation for improved control of citrus leafminer and citrus red mite

    NARCIS (Netherlands)

    Mele, van P.; Lenteren, van J.C.

    2002-01-01

    In the Mekong Delta, Vietnam, the citrus leafminer Phyllocnistis citrella (CLM) and the citrus red mite Panonychus citri are major pests in both sweet orange (Citrus sinensis) and Tieu mandarin (C. reticulata). Survey data indicate that these pest problems might be aggravated after farmers have comp

  9. Analysis of Transcriptome Differences between Resistant and Susceptible Strains of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae)

    OpenAIRE

    Bin Liu; Gaofei Jiang; Yunfei Zhang; Junli Li; Xiaojiao Li; Jiansu Yue; Fei Chen; Haoqiang Liu; Hongjun Li; Shiping Zhu; Jinjun Wang; Chun Ran

    2011-01-01

    BACKGROUND: The citrus red mite is a worldwide citrus pest and a common sensitizing allergen of asthma and rhinitis. It has developed strong resistance to many registered acaricides, However, the molecular mechanisms of resistance remain unknown. we therefore used next generation sequencing technology to investigate the global transcriptomes between resistant strains and susceptible strains. RESULTS: We obtained 34,159, 30,466 and 32,217 unigenes by assembling the SS reads, RS reads and SS&RS...

  10. γ辐照杀螨对伏令夏橙果实生理效应的初步研究%Preliminary Study on the Physiological Effects of γ -irradiation on Valencia Late Orange for Disinfestation of Citrus Rust Mites

    Institute of Scientific and Technical Information of China (English)

    陈巧玲; 叶蕙; 胡美英; 罗雪梅

    2001-01-01

    @@ 伏令夏橙(Citrus sinensis Osb)是我国重要的反季节鲜果之一,但采后螨害严重.笔者选择0.3~0.6 kGy剂量辐照杀螨,并对杀螨后伏令夏橙果实营养成分和贮存期间生理效应的变化做了初步的研究.

  11. 柑橘全爪螨种群空间格局的地学统计学分析%Geostatistic analysis of spatial pattern of the citrus red mite, Panonychus cirri (McGregor) ( Acarina: Tetranychidae) in citrus orchard

    Institute of Scientific and Technical Information of China (English)

    李志强; 梁广文; 岑伊静

    2008-01-01

    The citrus red mite, Panonychus citri (McGregor), is a key pest of citrus. Geostatistic method was applied to study the spatial pattern of citrus red mite population, in citrus orchard by the spatial analysis software Variowin 2.1, The results indicated that the spatial pattern of citrus red mite population can be described by geostatistic method, and the semivariogram of citrus red mite mainly fitted the gauss models with the ranges of 1.1-21.0 m. Citrus red mite population showed an aggregative distribution, and the aggregating intensities were relatively strong in March, August and September. The spatial pattern dynamics showed that two occurrence peaks of citrus red mite population occurred in April and October, specially in October, citrus red mite popula-tion rapidly diffused. March and September were two crucial stages of monitoring and treatment for citrus red mite.%应用地学统计学方法分析了柑橘园主要害螨柑橘全爪螨Panonychus citri(McGregor)种群的空间格局及其动态.结果表明,柑橘全爪螨种群具有空间相关性,变程介于1.10~21.0 m,其半变异函数主要符合高斯模型,表现为聚集分布,其中3月、8月和9月的聚集强度较大;种群空间格局动态显示,4月、10月为该种群的两个发生高峰期,柑橘全爪螨种群数量快速上升扩散.地学统计学方法能够应用于柑橘全爪螨种群的空间格局分析,并有助于对该害螨进行发生预测与控制处理.

  12. Identification and Characterization of Seven Glutathione S-Transferase Genes from Citrus Red Mite, Panonychus citri (McGregor

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    Chong-Yu Liao

    2013-12-01

    Full Text Available The citrus red mite, Panonychus citri (McGregor, is a global citrus pest, and has developed severe resistance to several types of acaricides. However, the molecular mechanisms of resistance in this mite remain unknown. In this study, seven full-length cDNAs encoding glutathione S-transferases (GSTs genes were identified and characterized in P. citri. The effects of pyridaben and fenpropathrin exposure on the expression of these genes were also investigated. Phylogenetic analysis revealed that the seven GSTs genes in P. citri cloned in this study belong to three different cytosolic classes, including four in mu, two in delta and one in zeta. Among these seven GSTs genes, the relative expression level of PcGSTm1 was significantly higher in adult than in the other life stages (egg, larvae and nymph. Compared with the control, the mRNA levels of the seven GST genes did not change significantly following exposure to pyridaben at LC10. However, RT-qPCR results showed that, when exposed to LC10 of fenpropathrin, six GSTs gene (PcGSTm1, PcGSTm3, PcGSTm4, PcGSTd1, PcGSTd2 and PcGSTz1 transcripts increased in a time-dependent manner. This is the first insight into the molecular characteristics of GSTs gene cDNAs in P. citri. The elevated GSTs gene transcripts following exposure to fenpropathrin might be one of the mechanisms involved in detoxification of this acaricide.

  13. Analysis of transcriptome differences between resistant and susceptible strains of the citrus red mite Panonychus citri (Acari: Tetranychidae.

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    Bin Liu

    Full Text Available BACKGROUND: The citrus red mite is a worldwide citrus pest and a common sensitizing allergen of asthma and rhinitis. It has developed strong resistance to many registered acaricides, However, the molecular mechanisms of resistance remain unknown. we therefore used next generation sequencing technology to investigate the global transcriptomes between resistant strains and susceptible strains. RESULTS: We obtained 34,159, 30,466 and 32,217 unigenes by assembling the SS reads, RS reads and SS&RS reads respectively. There are total 17,581 annotated unigenes from SS&RS reads by BLAST searching databases of nr, the Clusters of Orthologous Groups (COGs and Kyoto Encyclopedia of Genes and Genomes (KEGG with an E-value ≤ 1e-5, in which 7,075 unigenes were annotated in the COG database, 12, 712 unigenes were found in the KEGG database and 3,812 unigenes were assigned to Gene ontology (GO. Moreover, 2,701 unigenes were judged to be the differentially expressed genes (DEGs based on the uniquely mapped reads. There are 219 pathways in all annotated unigenes and 198 pathways in DEGs that mapped to the KEGG database. We identified 211 metabolism genes and target genes related to general insecticide resistance such as P450 and Cytochrome b, and further compared their differences between RS and SS. Meanwhile, we identified 105 and 194 genes related to growth and reproduction, respectively, based on the mode of action of Hexythiazox. After further analyses, we found variation in sequences but not in gene expression related to mite growth and reproduction between different strains. CONCLUSION: To our knowledge, this is the first comparative transcriptome study to discover candidate genes involved in phytophagous mite resistance. This study identified differential unigenes related to general pesticide resistance and organism growth and reproduction in P. citri. The assembled, annotated transcriptomes provide a valuable genomic resource for further understanding

  14. 60Co-γ Irradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae

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    Ke Zhang

    2014-05-01

    Full Text Available Radio-(60Co, which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD, catalase (CAT, peroxidase (POD, phenoloxidase (PO and acetylocholinesterase (AchE were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.

  15. Parallel evolution of cytochrome b mediated bifenazate resistance in the citrus red mite Panonychus citri

    NARCIS (Netherlands)

    Van Leeuwen, T.; Van Nieuwenhuyse, P.; Vanholme, B.; Dermauw, W.; Nauen, R.; Tirry, L.

    2011-01-01

    Bifenazate is a recently developed acaricide that is mainly used to control spider mites on a variety of crops. Although first thought to be a neurotoxin, genetic evidence obtained from bifenazate resistant Tetranychus urticae strains suggested an alternative mode of action as a Qo pocket inhibitor

  16. Molecular Characterization of Vitellogenin and Its Receptor Genes from Citrus Red Mite, Panonychus citri (McGregor

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    Rui Zhong

    2015-03-01

    Full Text Available The production and uptake of yolk protein play an important role in the reproduction of all oviparous organisms. Vitellogenin (Vg is the precursor of vitellin (Vn, which is the major egg storage protein, and vitellogenin receptor (VgR is a necessary protein for the uptake of Vg into developing oocytes. In this paper, we characterize the full-length Vg and VgR, PcVg1 and PcVgR, respectively, of the citrus red mite Panonychus citri (McGregor. The PcVg1 cDNA is 5748 nucleotides (nt with a 5553-nt open reading frame (ORF coding for 1851 amino acids (aa, and the PcVgR is 6090 nt, containing an intact ORF of 5673 nt coding an expected protein of 1891 aa. The PcVg1 aa sequence shows a typical GLCG domain and several K/RXXR cleavage sites, and PcVgR comprises two ligand-binding domains, two epidermal growth factor (EGF-like regions containing YWTD motifs, a transmembrane domain, and a cytoplasmic domain. An analysis of the aa sequences and phylogenetics implied that both genes were genetically distinct from those of ticks and insects. The transcriptional profiles determined by real-time quantitative PCR in different developmental stages showed that both genes present the same expressional tendencies in eggs, larvae, nymphs, and adults. This suggested that the biosynthesis and uptake of PcVg occurs coordinately. The strong reproductive capacity of P. citri has been hypothesized as an important factor in its resistance; consequently, understanding the molecular mechanisms regulating Vg and VgR are fundamental for mite control.

  17. Citrus leprosis virus C Infection Results in Hypersensitive-Like Response, Suppression of the JA/ET Plant Defense Pathway and Promotion of the Colonization of Its Mite Vector

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    Arena, Gabriella D.; Ramos-González, Pedro L.; Nunes, Maria A.; Ribeiro-Alves, Marcelo; Camargo, Luis E. A.; Kitajima, Elliot W.; Machado, Marcos A.; Freitas-Astúa, Juliana

    2016-01-01

    Leprosis is a serious disease of citrus caused by Citrus leprosis virus C (CiLV-C, genus Cilevirus) whose transmission is mediated by false spider mites of the genus Brevipalpus. CiLV-C infection does not systemically spread in any of its known host plants, thus remaining restricted to local lesions around the feeding sites of viruliferous mites. To get insight into this unusual pathosystem, we evaluated the expression profiles of genes involved in defense mechanisms of Arabidopsis thaliana and Citrus sinensis upon infestation with non-viruliferous and viruliferous mites by using reverse-transcription qPCR. These results were analyzed together with the production of reactive oxygen species (ROS) and the appearance of dead cells as assessed by histochemical assays. After interaction with non-viruliferous mites, plants locally accumulated ROS and triggered the salicylic acid (SA) and jasmonate/ethylene (JA/ET) pathways. ERF branch of the JA/ET pathways was highly activated. In contrast, JA pathway genes were markedly suppressed upon the CiLV-C infection mediated by viruliferous mites. Viral infection also intensified the ROS burst and cell death, and enhanced the expression of genes involved in the RNA silencing mechanism and SA pathway. After 13 days of infestation of two sets of Arabidopsis plants with non-viruliferous and viruliferous mites, the number of mites in the CiLV-C infected Arabidopsis plants was significantly higher than in those infested with the non-viruliferous ones. Oviposition of the viruliferous mites occurred preferentially in the CiLV-C infected leaves. Based on these results, we postulated the first model of plant/Brevipalpus mite/cilevirus interaction in which cells surrounding the feeding sites of viruliferous mites typify the outcome of a hypersensitive-like response, whereas viral infection induces changes in the behavior of its vector. PMID:27933078

  18. Citrus leprosis virus C infection results in hypersensitive-like response, suppression of the JA/ET plant defense pathway and promotion of the colonization of its mite vector.

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    Gabriella Dias Arena

    2016-11-01

    Full Text Available Leprosis is a serious disease of citrus caused by Citrus leprosis virus C (CiLV-C, genus Cilevirus whose transmission is mediated by false-spider mites of the genus Brevipalpus. CiLV-C infection does not systemically spread in any of its known host plants, thus remaining restricted to local lesions around the feeding sites of viruliferous mites. To get insight into this unusual pathosystem, we evaluated the expression profiles of genes involved in defense mechanisms of Arabidopsis thaliana and Citrus sinensis upon infestation with non-viruliferous and viruliferous mites by using reverse transcriptase-qPCR. These results were analyzed together with the production of reactive oxygen species (ROS and the appearance of dead cells as assessed by histochemical assays. After interaction with non-viruliferous mites, plants locally accumulated ROS and triggered the salicylic acid (SA and jasmonate/ethylene (JA/ET pathways. ERF branch of the JA/ET pathways was highly activated. In contrast, JA pathway genes were markedly suppressed upon the CiLV-C infection mediated by viruliferous mites. Viral infection also intensified the ROS burst and cell death, and enhanced the expression of genes involved in the RNA silencing mechanism and SA pathway. After 13 days of infestation of two sets of Arabidopsis plants with non-viruliferous and viruliferous mites, the number of mites in the CiLV-C infected Arabidopsis plants was significantly higher than in those infested with the non-viruliferous ones. Oviposition of the viruliferous mites occurred preferentially in the CiLV-C infected leaves. Based on these results, we postulated the first model of plant/Brevipalpus mite/cilevirus interaction in which cells surrounding the feeding sites of viruliferous mites typify the outcome of a hypersensitive-like response, whereas viral infection induces changes in the behavior of its vector.

  19. Exposure to Diflubenzuron Results in an Up-Regulation of a Chitin Synthase 1 Gene in Citrus Red Mite, Panonychus citri (Acari: Tetranychidae

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    Wen-Kai Xia

    2014-02-01

    Full Text Available Chitin synthase synthesizes chitin, which is critical for the arthropod exoskeleton. In this study, we cloned the cDNA sequences of a chitin synthase 1 gene, PcCHS1, in the citrus red mite, Panonychus citri (McGregor, which is one of the most economically important pests of citrus worldwide. The full-length cDNA of PcCHS1 contains an open reading frame of 4605 bp of nucleotides, which encodes a protein of 1535 amino acid residues with a predicted molecular mass of 175.0 kDa. A phylogenetic analysis showed that PcCHS1 was most closely related to CHS1 from Tetranychus urticae. During P. citri development, PcCHS1 was constantly expressed in all stages but highly expressed in the egg stage (114.8-fold higher than in the adult. When larvae were exposed to diflubenzuron (DFB for 6 h, the mite had a significantly high mortality rate, and the mRNA expression levels of PcCHS1 were significantly enhanced. These results indicate a promising use of DFB to control P. citri, by possibly acting as an inhibitor in chitin synthesis as indicated by the up-regulation of PcCHS1 after exposure to DFB.

  20. Non-phytoseiid Mesostigmata within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants and additional collection records of mites in citrus orchards.

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    Childers, Carl C; Ueckermann, Eduard A

    2015-03-01

    Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the

  1. Mites (Arachnida, Acari on Citrus sinensis L. Osbeck orange trees in the state of Amazonas, Northern Brazil Ácarofauna de Citrus sinensis L. Osbeck no estado do Amazonas, Brasil

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    Teiamar da Encarnação Bobot

    2011-01-01

    Full Text Available Despite the importance of citriculture in Brazil, very little is known about mite populations in citrus crops in the Northern Region. In the municipality of Manaus, 12 sprayed sweet orange orchards were surveyed every two weeks during seven months to record mite species amount, and to describe the abundance and distribution of the most important species. The size and age of the orchards varied from 3,360 to 88,080 m² and seven to 25 years, respectively. In the fourteen sampling period, leaves, twigs and fruits were collected from 12 trees, one per orchard. In total, 3,360 leaves, 672 twigs and 1,344 fruits were sampled from 168 trees. Mites were manually extracted from the fruits, and by the washing method on leaves and twigs. We identified pests with the potential to cause economic loss. Fourteen species of phytophagous and mycophagous mites from Eriophyidae, Tarsonemidae, Tenuipalpidae, and Tetranychidae were recorded. Brevipalpus phoenicis (Geijskes 1939 and Phyllocoptruta oleivora (Ashm., 1879, the two commonest phytophagous mites in other Brazilian regions were dominant, showing that local orchards are susceptible to their infestation. Eleven predatory mites were recorded, comprising 10% of the mite population, belonging to Phytoseiidae and Ascidae. Phytoseiidae was the richest family, with ten species. The results are discussed in relation to the temporal variation aspects and habitat use of the most important species. Long-term research encompassing chemical applications followed by evaluations of the mite community are necessary for a better management of the orchards, taking into consideration the seasonal phenology of key pests.Apesar da importância da citricultura no Brasil, pouco se conhece sobre as populações de ácaros em plantações de citros no norte do país. No município de Manaus, 12 pomares de laranja doce pulverizados foram avaliados a cada duas semanas, durante sete meses, para o registro de ácaros plantícolas e

  2. The economic importance of acaricides in the control of phytophagous mites and an update on recent acaricide mode of action research.

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    Van Leeuwen, Thomas; Tirry, Luc; Yamamoto, Atsushi; Nauen, Ralf; Dermauw, Wannes

    2015-06-01

    Acaricides are one of the cornerstones of an efficient control program for phytophagous mites. An analysis of the global acaricide market reveals that spider mites such as Tetranychus urticae, Panonychus citri and Panonychus ulmi are by far the most economically important species, representing more than 80% of the market. Other relevant mite groups are false spider mites (mainly Brevipalpus), rust and gall mites and tarsonemid mites. Acaricides are most frequently used in vegetables and fruits (74% of the market), including grape vines and citrus. However, their use is increasing in major crops where spider mites are becoming more important, such as soybean, cotton and corn. As revealed by a detailed case study of the Japanese market, major shifts in acaricide use are partially driven by resistance development and the commercial availability of compounds with novel mode of action. The importance of the latter cannot be underestimated, although some compounds are successfully used for more than 30 years. A review of recent developments in mode of action research is presented, as such knowledge is important for devising resistance management programs. This includes spirocyclic keto-enols as inhibitors of acetyl-CoA carboxylase, the carbazate bifenazate as a mitochondrial complex III inhibitor, a novel class of complex II inhibitors, and the mite growth inhibitors hexythiazox, clofentezine and etoxazole that interact with chitin synthase I.

  3. The effect of repeated release of the predatory mite Neoseiulus (Amblyseius) cucumeris on arthropod communities in citrus ecosystems

    OpenAIRE

    Jie Ji; Yanxuan Zhang; Xia Chen; Jianzhen Lin; Li Sun

    2012-01-01

    In order to study the effect of repeated release of Neoseiulus (Amblyseius) cucumeris on the species composition and diversity of arthropod community in citrus ecosystems, we established bio-control orchards, natural orchards and chemical control orchards in the Mawei and Jin’an experimental field of Fuzhou, China. Our results indicated that the species richness of bio-control orchards was higher than that of natural or chemical control orchards at both sites. Diversity and evenness indices w...

  4. The complete mitochondrial genome of the citrus red mite Panonychus citri (Acari: Tetranychidae): high genome rearrangement and extremely truncated tRNAs.

    Science.gov (United States)

    Yuan, Ming-Long; Wei, Dan-Dan; Wang, Bao-Jun; Dou, Wei; Wang, Jin-Jun

    2010-10-23

    The family Tetranychidae (Chelicerata: Acari) includes ~1200 species, many of which are of agronomic importance. To date, mitochondrial genomes of only two Tetranychidae species have been sequenced, and it has been found that these two mitochondrial genomes are characterized by many unusual features in genome organization and structure such as gene order and nucleotide frequency. The scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks). Information on Tetranychidae mitochondrial genomes is quite important for phylogenetic evaluation and population genetics, as well as the molecular evolution of functional genes such as acaricide-resistance genes. In this study, we sequenced the complete mitochondrial genome of Panonychus citri (Family Tetranychidae), a worldwide citrus pest, and provide a comparison to other Acari. The mitochondrial genome of P. citri is a typical circular molecule of 13,077 bp, and contains the complete set of 37 genes that are usually found in metazoans. This is the smallest mitochondrial genome within all sequenced Acari and other Chelicerata, primarily due to the significant size reduction of protein coding genes (PCGs), a large rRNA gene, and the A + T-rich region. The mitochondrial gene order for P. citri is the same as those for P. ulmi and Tetranychus urticae, but distinctly different from other Acari by a series of gene translocations and/or inversions. The majority of the P. citri mitochondrial genome has a high A + T content (85.28%), which is also reflected by AT-rich codons being used more frequently, but exhibits a positive GC-skew (0.03). The Acari mitochondrial nad1 exhibits a faster amino acid substitution rate than other genes, and the variation of nucleotide substitution patterns of PCGs is significantly correlated with the G + C content. Most tRNA genes of P. citri are extremely truncated and atypical (44-65, 54.1 ± 4.1 bp), lacking either the T- or D-arm, as found in P. ulmi

  5. The complete mitochondrial genome of the citrus red mite Panonychus citri (Acari: Tetranychidae: high genome rearrangement and extremely truncated tRNAs

    Directory of Open Access Journals (Sweden)

    Dou Wei

    2010-10-01

    Full Text Available Abstract Background The family Tetranychidae (Chelicerata: Acari includes ~1200 species, many of which are of agronomic importance. To date, mitochondrial genomes of only two Tetranychidae species have been sequenced, and it has been found that these two mitochondrial genomes are characterized by many unusual features in genome organization and structure such as gene order and nucleotide frequency. The scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks. Information on Tetranychidae mitochondrial genomes is quite important for phylogenetic evaluation and population genetics, as well as the molecular evolution of functional genes such as acaricide-resistance genes. In this study, we sequenced the complete mitochondrial genome of Panonychus citri (Family Tetranychidae, a worldwide citrus pest, and provide a comparison to other Acari. Results The mitochondrial genome of P. citri is a typical circular molecule of 13,077 bp, and contains the complete set of 37 genes that are usually found in metazoans. This is the smallest mitochondrial genome within all sequenced Acari and other Chelicerata, primarily due to the significant size reduction of protein coding genes (PCGs, a large rRNA gene, and the A + T-rich region. The mitochondrial gene order for P. citri is the same as those for P. ulmi and Tetranychus urticae, but distinctly different from other Acari by a series of gene translocations and/or inversions. The majority of the P. citri mitochondrial genome has a high A + T content (85.28%, which is also reflected by AT-rich codons being used more frequently, but exhibits a positive GC-skew (0.03. The Acari mitochondrial nad1 exhibits a faster amino acid substitution rate than other genes, and the variation of nucleotide substitution patterns of PCGs is significantly correlated with the G + C content. Most tRNA genes of P. citri are extremely truncated and atypical (44-65, 54.1 ± 4.1 bp, lacking

  6. Rust scoring guide

    NARCIS (Netherlands)

    Anonymous,

    1986-01-01

    This brief guide for identifying rust diseases of smaill grain cereals contains color photos depicting the growth stages of small grain cereal crops and provides instructions for recording rust severity and field response for stripe rust (Puccinia striiformis), stem rust (P. graminis), and leaf rust

  7. Rust essentials

    CERN Document Server

    Balbaert, Ivo

    2015-01-01

    This book is intended for software developers interested in systems level and application programming, and are looking for a quick entry into using Rust and understanding the core features of the framework. It is assumed that you have a basic understanding of Java, C#, Ruby, Python or JavaScript.

  8. Bioassay on oviposition repellency of non-preferable plant extracts against citrus red mite Panonychus citri%非嗜食植物提取物对桔全爪螨产卵的驱避性测定

    Institute of Scientific and Technical Information of China (English)

    岑伊静; 庞雄飞; 周琼; 彭跃峰; 徐长宝

    2004-01-01

    The oviposition repellency of the alcohol extracts from 50 species of non-preferable plants and azadirachtin against citrus red mite ( Panonychus cirri ) was determined using laboratory bioassays. In choice tests, the extracts from 42 of the 50 plant species and 1% azadirachtin (2000×) significantly reduced oviposition 1d after treatment.The repellency effect of the extracts from the 42 plant species was better than that of azadirachtin. Mikania micrantha extract had the best result, with an Interference Index of Population Control (IIPC) of 0.087 1 d after treatment, and significantly reduced oviposition for 9 d, while the extracts from Sesbania cannabina, Allium tuberosum , Paederia scandens , Duranta erecta and Dicranopteris pedata also had good effects, with an oviposition repellency of over 70 % 1 d after treatment, and significantly reduced oviposition for 4 - 6 d. The effect became weaker as time went on. None of the extracts showed significant oviposition attraction.

  9. Toxicidade diferencial de produtos à base de abamectina ao ácaro Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae em citros Differential toxicity of abamectin based products over Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae mite in citrus

    Directory of Open Access Journals (Sweden)

    Daniel Júnior de Andrade

    2010-03-01

    Full Text Available O ácaro Brevipalpus phoenicis é uma das principais pragas dos citros por ser vetor do "Citrus Leprosis Virus" (CiLV, agente causal da leprose, uma das mais graves doenças da citricultura. Objetivou-se avaliar o efeito tóxico de produtos à base de abamectina sobre o ácaro B. phoenicis. Foram realizados um experimento de ação direta e três de ação residual no Laboratório de Acarologia do Departamento de Proteção de Plantas (Fitossanidade da FCAV - UNESP, Jaboticabal-SP. O delineamento adotado nos bioensaios foi o inteiramente casualizado, onde 10 tratamentos foram repetidos 7 vezes, sendo cada repetição composta por um fruto de laranja. Os tratamentos estudados (mL p.c./100 L de água foram: Acaramik a 20; 30; 40 e 50 mL; Vertimec a 30 e 40 mL; Abamectin Nortox a 30 e 40 mL; Tricofol a 77 mL e uma testemunha sem aplicação. Utilizaram-se frutos com presença de verrugose, que foram lavados e parcialmente parafinados, deixando-se uma área sem parafina, que foi circundada com cola entomológica para contenção dos ácaros. Transferiram-se 20 ácaros adultos B. phoenicis para cada fruto. No bioensaio de ação direta, a transferência foi realizada antes das aplicações e, nos bioensaios de ação residual, aos 5; 10 e 15 dias após a aplicação dos produtos. A aplicação dos produtos sobre os frutos foi realizada em Torre de Potter. Os resultados obtidos nos bioensaios evidenciaram que os melhores tratamentos foram: Tricofol a 77 mL, Acaramik a 40 e 50 mL e Vertimec a 40 mL. De forma geral, os produtos testados podem ser utilizados no controle do ácaro B. phoenicis.The mite Brevipalpus phoenicis (Geijskes, 1939 (Acari: Tenuipalpidae is one of the most important pests in Brazil citrus plantation, because it is the virus "Citrus Leprosis Virus" (CiLV vector, one of the most serious citrus plantation diseases. The purpose of this experiment was to evaluate the toxical effect of abamectin in the mite B. phoenicis. It was performed

  10. Atividade do acaricida etoxazol sobre a mortalidade e reprodução do ácaro-da-leprose Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae, em citros Activity of the etoxazole acaricide on the mortality and reproduction of the citrus leprosis mite Brevipalpus Phoenicis (Geijskes (Acari: Tenuipalpidae, in citrus

    Directory of Open Access Journals (Sweden)

    Fernando Juari Celoto

    2010-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a atividade do acaricida etoxazol, no controle e reprodução do ácaro B. phoenicis. Para tanto, foram demarcadas com cola adesiva arenas de cinco centímetros de diâmetro em frutos de citros com alta infestação do ácaro. O ensaio foi delineado em parcelas inteiramente casualizadas, com oito tratamentos e quatro repetições. Em cada arena foram contados o número de ácaros adultos, jovens e ovos. Os tratamentos constaram dos seguintes acaricidas e doses em g i.a./100 L de água: etoxazol 110 SC (1,1; 1,65; 2,75 e 5,5; hexitiazoxi 500 PM (0,75; flufenoxuron 100 CE (3; cihexatina 500 PM (25, aplicados diretamente sobre as arenas. Os frutos foram mantidos em câmara de germinação tipo BOD. com temperatura de 25 ± 2 ºC e fotofase de 12 horas. Diariamente, foram contados o número de ácaros adultos, jovens e ovos, com auxílio de microscópio esteroscópio. Os parâmetros avaliados foram a atividade ovicida, esterilização de fêmeas e efeito sobre formas jovens. Constatou-se que o etoxazol provocou mortalidade de formas jovens do ácaro-da-leprose superior a 95%, nas doses a partir de 1,1 g i.a. /100 L de água. Ovos tratados com etoxazol, nas doses a partir de 1,65 g i.a. /100 L de água, apresentaram inviabilidade média de 60%. O etoxazol apresentou efeito esterilizante sobre fêmeas nas doses a partir de 2,75 g i.a./100 L de água, inviabilizando 95% dos ovos.The objective of this work was to evaluate the activity of the etoxazole acaricide, on the mortality and reproduction of the citrus leprosies mite, B. phoenicis. A five centimeter diameter arena were demarcated with adhesive glue, in citrus fruits with high infestation of the mite. The design was entirely randomized plots with eight treatments and four replications. In each arena were counted the number of adults, young and eggs of B. phoenicis. The treatments consisted the following acaricides and doses in g a.i./100 L of water: etoxazole

  11. 用高光谱成像技术检测柑橘红蜘蛛为害叶片的色素含量%Pigment content measurement for citrus red mite infected leaf using hyper-spectral imaging technology

    Institute of Scientific and Technical Information of China (English)

    李震; 洪添胜; 倪慧娜; 李楠; 王建; 郑建宝; 林瀚

    2014-01-01

    In order to solve the high workload and low efficiency problems while measuring the pigment content variation of citrus red mite infested leaves using the traditional physical and chemical methods, a novel pigment content measurement method for citrus red mite infested leaf using the hyper-spectral imaging technology was studied in this paper. In the research, 400 healthy leaves and 400 sick leaves were included as the test samples in which 350 healthy leaves and 350 sick leaves were utilized for model establishment and the other 50 leaves of each type were used for a model test. Each leaf’s original spectrum and its first order deviation in its particular healthy and sick area were acquired to investigate the characteristic spectrum bands which could mostly reflect the variation of leaf pigment content. The correlation between characteristic spectrum band ratios and pigment content was analyzed. An univariate linear regression method was applied to analyze the pigment content prediction effect using the common vegetation indexes. A leaf pigment content prediction model was established, using the stepwise regression method, and the model’s prediction ability was tested using the F test. Experimental results indicated that it is not satisfactory using the common vegetation indexes to predict leaf pigment content since they are not specially selected for citrus trees. The selected three characteristic spectrum band ratios of 667/522, 667/647, and 522/647 nm, each of which has a high correlation with a leaf’s three types of pigment content, were applied in the stepwise regression method to establish pigment content prediction models. Two out of three of the characteristic spectrum band ratios of 667/522 and 667/647 nm, which gave the best performance, were used as independent values for model establishment. The F test results indicated that the established models could preferably predict both healthy and sick leaves chlorophyll a, chlorophyll b, and carotenoid

  12. EFFICIENCY OF NEEM OIL ON CITRUS LEPROSIS MITE Brevipalpus phoenicis (GEIJSKES, 1939 CONTROL EFICIÊNCIA DO ÓLEO DE NEEM NO CONTROLE DO ÁCARO DA LEPROSE DOS CITROS Brevipalpus phoenicis (GEIJSKES, 1939

    Directory of Open Access Journals (Sweden)

    Cleber Daniel de Goes Maciel

    2009-01-01

    -bidi-language:#0400;}

    In order to determine the efficiency of neem oil on citrus leprosis mite, Brevipalpus phoenicis (Geijskes, control, a laboratory test was conducted in Jaboticabal, São Paulo State, Brazil, using a completely randomized design, with six treatments and six repetitions. Each plot was formed by one orange fruit (Pêra Rio variety. An area with 4 cm of diameter was delimited in each fruit, using Tanglefoot® adhesive. The methodology consisted in submerging each fruit of each treatment in the solution prepared with neem oil (Nim-I-Go®, with 0.5%, 1.0%, 1.5%, and 2.0% v/v; cyhexatin, with 0.025% v/v; and a check submerged in water. After 30 minutes of submersion, eight mites were placed in each fruit and evaluations were made after 24, 48, and 72 hours, determining the mite survival, mortality rate, and mites adhered to the glue. It was found that neem oil, at 1.5% v/v, showed high efficiency to control B. phoenicis on orange fruits, also obtaining the largest number of mites adhered to the glue. It may be concluded that, at this concentration, the product showed repellence action. Under laboratory conditions, the neem oil was effective for citrus leprosis mite control.

     

    KEY-WORDS: Citrus leprosis mite; Azadirachta indica.

  1. Brevipalpus phoenicis (group species B) on Citrus spp. and Coffea arabica, State of Sao Paulo, Brazil.

    Science.gov (United States)

    Some mite species of the genus Brevipalpus are considered pests of economic importance for several agricultural crops such as citrus and coffee. They are associated with the transmission of viruses [e.g.:citrus leprosis virus (CiLV), coffee ringspot virus (CoRSV)]. Recent studies indicate that the ...

  2. Citrus pulp for cattle.

    Science.gov (United States)

    Arthington, John D; Kunkle, William E; Martin, Amy M

    2002-07-01

    Citrus pulp is classified as an energy concentrate by-product feed. Citrus by-products fed to beef cattle include citrus molasses, citrus meal, wet citrus pulp, dried citrus pulp, and pelleted citrus pulp; however, in current production systems, pulp (wet, dry, and pelleted) is the only by-product commonly used. Citrus pulp production in the United States is limited to specific subtropical regions, of which south central Florida remains the largest with additional production in California and Texas.

  3. Efeito da utilização de acaricidas em citros, sobre a população de Brevipalpus phoenicis (Geijskes, 1939 e ácaros predadores (Phytoseiidae Effect of acaricide utilization in citrus on the population of Brevipalpus phoenicis (Geijskes, 1939 and predatory mites (Phytoseiidae

    Directory of Open Access Journals (Sweden)

    M.E. Sato

    1995-08-01

    Full Text Available Foi conduzido experimento com o objetivo de estudar o efeito de alguns acaricidas sobre Brevipalpus phoenicis (Geijskes,1939 (AcarirTenuipalpidae e ácaros predadores (Phytoseiidae, em citros. Os produtos testados e as dosagens em g i.a./100 / de água foram: fenpyroximate (5,0, acrinathrin (0,5; hexythiazox (1,5; amitraz (40,0 e enxofre (225,0. Os acaricidas fenpyroximate, acrinathrin e hexythiazox foram eficientes contra B. phoenicis até 127 dias após a aplicação, enquanto que, o enxofre e o amitraz apresentaram bom controle até 92 e 58 dias após o tratamento, respectivamente. O hexythiazox foi praticamente inócuo aos ácaros predadores mas os demais acaricidas foram significativamente prejudiciais a estes ácaros. Os produtos enxofre, fenpyroximate e acrinathrin induziram reduções na população de fitoseíídeos até 58 dias, porém o amitraz apresentou reduções até 92 dias após a pulverização.The experiment was carried out in order to study the effects of some acaricides on Brevipalpus phoenicis (Geijskes,1939 (Acari,Tenuipalpidae and predatory mites (Phytoseiidae hi citrus. The products tested and dosages in g AI/ 100 / of water were: fenpyroximate (5.0, acrinathrin (0.5, hexythiazox (1.5, amitraz (40.0 and sulphur (225.0. The acaricides fenpyroximate, acrinathrin and hexythiazox were efficient against B. phoenicis up to 127 days from the application date, whereas sulphur and amitraz presented good control up to 92 days and 58 days after treatment, respectively. Hexythiazox was fairly innocuous to predatory mites but, the remaining acaricides caused significant mortality to these mites. The pesticides sulphur, fenpyroximate and acrinathrin induced reductions of the population of phytoseid mites up to 58 days, but amitraz showed reductions up to 92 days after application.

  4. The effect of repeated release of the predatory mite Neoseiulus (Amblyseius) cucumeris on arthropod communities in citrus ecosystems%多次释放胡瓜新小绥螨对橘园节肢动物群落多样性的影响

    Institute of Scientific and Technical Information of China (English)

    季洁; 张艳璇; 陈霞; 林坚贞; 孙莉

    2012-01-01

    为了探明长期多次释放胡瓜新小绥螨(Neoseiulus (Amblyseius) cucumeris)是否会对橘园节肢动物群落的生物多样性产生影响,我们在福州马尾和晋安试验区的2个橘园分别设置生防园、自然园和化防园,连续两年每月两次在各处理橘园的树冠和地面杂草中采集并记录节肢动物的种类和数量,结果表明两个试验区的物种丰富度(S)均以生防园最高,且都显著高于相应的化防园和自然园;马尾试验区三种处理的多样性指数(H)和均匀度指数(E)的大小依次为生防园>自然园>化防园,晋安试验区则为自然园>生防园>化防园,表明释放胡瓜新小绥螨防治柑橘害螨,减少农药的使用,能恢复或增加橘园节肢动物群落的生物多样性.此外,释放胡瓜新小绥螨未对橘园原有的捕食螨类群产生影响.%In order to study the effect of repeated release of Neoseiulus {Amblyseius) cucumeris on the species composition and diversity of arthropod community in citrus ecosystems, we established bio-control orchards, natural orchards and chemical control orchards in the Mawei and Jin'an experimental field of Fuzhou, China. Our results indicated that the species richness of bio-control orchards was higher than that of natural or chemical control orchards at both sites. Diversity and evenness indices were higher in bio-control orchards than those of other orchards in the Mawei site, and those of chemical control orchards were the lowest. Among the variously managed orchards in Jin'an, evenness and diversity indices were highest in the natural orchards and lowest in chemical orchards. Our study suggests that citrus ecosystem arthropod diversity can be enhanced by releasing N. cucumeris to fight against the citrus pest mites while reducing the spraying of pesticide.

  5. Coincidental intraguild predation by caterpillars on spider mites.

    Science.gov (United States)

    Shirotsuka, Kanako; Yano, Shuichi

    2012-01-29

    Intraguild predation (IGP) is defined as the killing and eating of prey species by a predator that also can utilize the resources of the prey. It is mainly reported among carnivores that share common herbivorous prey. However, a large chewing herbivore could prey upon sedentary and/or micro herbivores in addition to utilizing a host plant. To investigate such coincidental IGP, we observed the behavioral responses of the polyphagous mite Tetranychus kanzawai Kishida (Acari: Tetranychidae) when its host plant Cayratia japonica (Thunb.) Gagnep. (Vitaceae) was attacked by hornworms, Theretra japonica Boisduval (Sphingidae) and T. oldenlandiae Fabricius (Sphingidae). We also examined an interaction between the oligophagous mite Panonychus citri McGregor (Acari: Tetranychidae) and caterpillars of the swallowtail Papilio xuthus L. (Papilionidae) that share citrus plants as their main food source. Although all T. kanzawai and some active stage P. citri tried to escape from the coincidental IGP, some were consumed together with eggs, quiescent mites, and host plant leaves, suggesting that coincidental IGP occurs on spider mites in the wild. Moreover, neither hornworms nor swallowtail caterpillars distinguished between spider mite-infested and uninfested leaves, suggesting that the mite-infested leaves do not discourage caterpillar feeding. The reasons that the mites have no effective defense against coincidental IGP other than escaping are discussed.

  6. Fighting Asian soybean rust

    Directory of Open Access Journals (Sweden)

    Caspar eLangenbach

    2016-06-01

    Full Text Available Phakopsora pachyrhizi is a biotrophic fungus provoking Asian soybean rust (SBR disease. SBR poses a major threat to global soybean production. Though several resistance genes provided soybean immunity to certain P. pachyrhizi races, the pathogen swiftly overcame this resistance. Therefore, fungicides are the only current means to control SBR. However, insensitivity to fungicides is soaring in P. pachyrhizi and, therefore, alternative measures are needed for SBR control. In this article, we discuss the different approaches for fighting SBR and their potential, disadvantages, and advantages over other measures. These encompass conventional breeding for SBR resistance, transgenic approaches, exploitation of transcription factors, secondary metabolites, and antimicrobial peptides, RNAi/HIGS, and biocontrol strategies. It seems that an integrating approach exploiting different measures is likely to provide the best possible means for the effective control of SBR.

  7. Mites and allergy.

    Science.gov (United States)

    Fernández-Caldas, Enrique; Puerta, Leonardo; Caraballo, Luis

    2014-01-01

    Allergic diseases triggered by mite allergens include allergic rhinoconjunctivitis, asthma, atopic dermatitis and other skin diseases. Since the early discovery of the allergenic role of mites of the genus Dermatophagoides in the mid 1960s, numerous species have been described as the source of allergens capable of sensitizing and inducing allergic symptoms in sensitized and genetically predisposed individuals. The main sources of allergens in house dust worldwide are the fecal pellets of the mite species D. pteronyssinus, D. farinae, Euroglyphus maynei and the storage mites Blomia tropicalis, Lepidoglyphus destructor and Tyropahgus putrescentiae. Group 1 and 2 allergens are major house dust mite allergens. The main allergens in storage mites include fatty acid-binding proteins, tropomyosin and paramyosin homologues, apolipophorin-like proteins, α-tubulins and others, such as group 2, 5 and 7 allergens. Cross-reactivity is an important and common immunological feature among mites. Currently, purified native or recombinant allergens, epitope mapping, proteomic approaches and T cell proliferation techniques are being used to assess cross-reactivity. Mites contain potent enzymes capable of degrading a wide range of substrates. Most mite allergens are enzymes. Advances in genomics and molecular biology will improve our ability to understand the genetics of specific IgE responses to mites. Mite allergen avoidance and immunotherapy are the only two allergen-specific ways to treat mite-induced respiratory and cutaneous diseases. © 2014 S. Karger AG, Basel.

  8. Development and reproduction of Panonychus citri (Prostigmata: Tetranychidae) on different species and varieties of citrus plants.

    Science.gov (United States)

    Zanardi, Odimar Zanuzo; Bordini, Gabriela Pavan; Franco, Aline Aparecida; de Morais, Matheus Rovere; Yamamoto, Pedro Takao

    2015-12-01

    The species and varieties of citrus plants that are currently grown can favor the population growth of the citrus red mite Panonychus citri (McGregor) (Prostigmata: Tetranychidae) and alter the pest management programs in citrus groves. In this study we evaluated, in the laboratory, the development and reproduction of P. citri and estimated its life table parameters when reared on four varieties of Citrus sinensis (L.) Osbeck (Valencia, Pera, Natal, and Hamlin), one variety of Citrus reticulata Blanco (Ponkan) and one variety of Citrus limon (L.) Burm. (Sicilian). The incubation period and egg viability were not affected by the host plant. However, the development and survival of the immature stage were significantly lower on Hamlin orange than on Valencia, Pera and Natal oranges, Ponkan mandarin and Sicilian lemon. The fecundity and oviposition period of females were lower on Hamlin orange than on the other hosts. Mites reared on Valencia orange and Sicilian lemon had a higher net reproductive rate (R 0 ), intrinsic growth rate (r) and finite rate of increase (λ), and a shorter interval between generations (T) than on Pera, Natal and Hamlin oranges and Ponkan mandarin. On the other hand, mites reared on Hamlin orange had the lowest R 0 , r and λ and the highest T among the hosts. Based on the results obtained we recommend that for Valencia orange and Sicilian lemon, the mite monitoring programs should be more intense to detect the initial infestation of pest, avoiding the damage in plants and the increase in production costs.

  9. Citrus leprosis research update

    Science.gov (United States)

    Citrus leprosis is one of the oldest citrus diseases, but is also one of the most important emerging citrus diseases in South and Central America, and it is apparently spreading northward towards the U.S. Research in our labs and by others has shown that citrus leprosis disease is caused by a compl...

  10. Gene identification and sequence analysis of Wolbachia in several common mites in citrus orchards%几种常见桔园螨类Wolbachia基因检测与序列分析

    Institute of Scientific and Technical Information of China (English)

    邹志文; 陈芬; 余丽萍; 夏斌

    2011-01-01

    Polymerase chain reaction ( PCR) was adopted to examine the wsp, ftsZ, and 16S rDNA of Wolbachia in Amblyseius orientalis, A. eharai, Euseius nicholsi, Neo.seiulus barkeri, Panonychus citri, and Tetranychus harti from the citrus orchards in Nanchang, Jiujiang, and Ganzhou of Jiangxi Province. It was found that only T. harti from the citrus orchards in Nanchang was infected by Wolbachia, with the fragments length of Wolbachia wsp ( Accession No. GQ162482) , ftsZ ( GQ162483) , and 16S rDNA ( GQ162484) being 593, 758, and 896 bp, respectively, while the other five species were uninfected. The Wolbachia in T. harti was very similar to the group Epo in subgroup B, based on the phylogenetic analysis of wsp gene.%应用共生菌沃尔巴克氏体Wolbachia的wsp、ftsZ和16S rDNA基因特异引物,通过PCR扩增法对采自江西省南昌、九江和赣州等3地桔园内的东方钝绥螨、江原钝绥螨、尼氏真绥螨、巴氏新小绥螨、桔全爪螨和酢浆草如叶螨等6种常见螨类进行了检测.结果表明,在采自南昌桔园内的酢浆草如叶螨体内检测到Wolbachia感染,其wsp、ftsZ和16S rDNA基因长度为593、758和896 bp,Genbank登录号依次为GQ162482、GQ162483和GQ162484,而其他5种螨体内均未检测出Wolbachia的感染;同时通过对酢浆草如叶螨体内感染的Wolbachia的wsp基因序列进行系统发育分析,得出其与B大组的Epo组的Wolbachia株十分相近,可能是相近或相同的株.

  11. Archaeophytopathology of Global Soybean Rust

    Science.gov (United States)

    Phakopsora pachyrhizi and P. meibomiae are two rust species that infect soybean (Glycine max). A number of other hosts support the uredinial growth of these Phakopsora, including Pachyrhizus erosus, Pueraria lobata, and Vigna unguiculata, but no aecial host is known. Traditionally, these two species...

  12. Disentangling mite predator-prey relationships by multiplex PCR.

    Science.gov (United States)

    Pérez-Sayas, Consuelo; Pina, Tatiana; Gómez-Martínez, María A; Camañes, Gemma; Ibáñez-Gual, María V; Jaques, Josep A; Hurtado, Mónica A

    2015-11-01

    Gut content analysis using molecular techniques can help elucidate predator-prey relationships in situations in which other methodologies are not feasible, such as in the case of trophic interactions between minute species such as mites. We designed species-specific primers for a mite community occurring in Spanish citrus orchards comprising two herbivores, the Tetranychidae Tetranychus urticae and Panonychus citri, and six predatory mites belonging to the Phytoseiidae family; these predatory mites are considered to be these herbivores' main biological control agents. These primers were successfully multiplexed in a single PCR to test the range of predators feeding on each of the two prey species. We estimated prey DNA detectability success over time (DS50), which depended on the predator-prey combination and ranged from 0.2 to 18 h. These values were further used to weight prey detection in field samples to disentangle the predatory role played by the most abundant predators (i.e. Euseius stipulatus and Phytoseiulus persimilis). The corrected predation value for E. stipulatus was significantly higher than for P. persimilis. However, because this 1.5-fold difference was less than that observed regarding their sevenfold difference in abundance, we conclude that P. persimilis is the most effective predator in the system; it preyed on tetranychids almost five times more frequently than E. stipulatus did. The present results demonstrate that molecular tools are appropriate to unravel predator-prey interactions in tiny species such as mites, which include important agricultural pests and their predators.

  13. Seletividade de alguns agrotóxicos em uso na citricultura ao ácaro predador Neoseiulus californicus (McGregor (Acari: Phytoseiidae Residual toxicity of the main pesticides recommended in citrus orchards on predaceous mite Neoseiulus californicus (Mcgregor (Acari: Phytoseiidae

    Directory of Open Access Journals (Sweden)

    Marcos Zatti da Silva

    2006-08-01

    Full Text Available Objetivou-se avaliar o efeito dos principais agrotóxicos utilizados em citros sobre Neoseiulus californicus (McGregor, em condições de laboratório, por tratar-se de um fitoseídeo com grande potencialidade para ser utilizado no controle dos ácaros fitófagos na cultura. O método de bioensaio adotado foi o de contato direto e residual. Folhas de citros da variedade Pêra, contendo 25 fêmeas adultas de N. californicus procedentes de uma criação-estoque, foram pulverizadas em torre de Potter. Avaliaram-se a mortalidade do ácaro 72 horas após a aplicação e o efeito dos produtos na viabilidade dos ovos. Quanto à seletividade, conforme proposta da "Organização Internacional para o Controle Biológico e Integrado de Plantas e Animais Nocivos" (IOBC, os produtos foram classificados como: classe 1 inócuo (E99%, clorfenapyr, dicofol e pyridaben. N. californicus mostrou-se tolerante a diversos agrotóxicos, o que viabiliza sua utilização, juntamente com produtos químicos pertencentes a grupamentos distintos e de diferentes mecanismos de ação, o que atende a um manejo adequado de controle dos principais ácaros fitófagos da cultura dos citros.This work was carried out to determine the residual toxicity of the main pesticides used in citrus, on Neoseiulus californicus (McGregor under laboratory conditions. For this, it was used the residual contact bioassay. Citrus leaves of the variety "Pêra" were sprayed in a Potter tower. The residual action was evaluated at 2 hours and 1; 3; 5; 7; 10; 14 e 21 days after treatment. Ten adult females of N. californicus were transferred to each ring, together with an enough amount of Tetranychus urticae nymphs and adults to feed the predator. Mortality evaluations were performed at 72 hours after treatment. Bioassays indicate that the pesticides: acrinathrin, deltamethrin, dinocap, sulphur, fenpropathrin, fenbutatin oxide and propargite were innocuous to N. californicus. On the other hand, abamectin

  14. Abnormal relationship between rust particles size and rust layer compactness of weathering steels

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to reveal evolution of the rust layer during atmospheric corrosion,commercial weathering steel(WS) 09CuPCrNi and a recently developed bainite WS were subjected to a salt fog test.The protection and compactness of the rust layer were evaluated by electrochemical analysis,absorption-desorption test,etc.The experimental results indicate that more compact rust layer could be derived from the rust particles with larger size.The well-established notion that the rust particle growth can induce the decreme...

  15. Genetic Transformation in Citrus

    Directory of Open Access Journals (Sweden)

    Dicle Donmez

    2013-01-01

    Full Text Available Citrus is one of the world’s important fruit crops. Recently, citrus molecular genetics and biotechnology work have been accelerated in the world. Genetic transformation, a biotechnological tool, allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. Citrus transformation has now been achieved in a number of laboratories by various methods. Agrobacterium tumefaciens is used mainly in citrus transformation studies. Particle bombardment, electroporation, A. rhizogenes, and a new method called RNA interference are used in citrus transformation studies in addition to A. tumefaciens. In this review, we illustrate how different gene transformation methods can be employed in different citrus species.

  16. In vitro and in vivo effect of Citrus limon essential oil against sarcoptic mange in rabbits

    Science.gov (United States)

    The effect of lemon oil (Citrus limon) on Sarcoptes scabiei var. cuniculi was evaluated in vitro and in vivo. The mite samples were collected from naturally infected rabbits. The lemon oil was prepared in six concentrations by dilution with distilled water (2.5, 5, 10, 20, 50, and 100 %). In vitro a...

  17. Molecular and genetic study of wheat rusts

    African Journals Online (AJOL)

    Nicholas Le Maitre

    Wheat rusts can cause losses as high as 70%. The rusts ability to ... Rotation of genes, that is, where different major resis- tance genes are ... and generate accurate results the same day (Brown,. 1996 ..... More work is required to assign these ...

  18. Leaf rust of wheat: Pathogen biology, variation and host resistance

    Science.gov (United States)

    Rusts are important pathogens of angiosperms and gymnosperms. Rust fungi are among the most important pathogens of cereals. Cereal rusts are heteroecious and macrocyclic requiring two taxonomically unrelated hosts to complete a five spore stage life cycle. Cereal rust fungi are highly variable for v...

  19. Rust-Bio: a fast and safe bioinformatics library

    NARCIS (Netherlands)

    J. Köster (Johannes)

    2015-01-01

    textabstractWe present Rust-Bio, the first general purpose bioinformatics library for the innovative Rust programming language. Rust-Bio leverages the unique combination of speed, memory safety and high-level syntax offered by Rust to provide a fast and safe set of bioinformatics algorithms and data

  20. Citrus Waste Biomass Program

    Energy Technology Data Exchange (ETDEWEB)

    Karel Grohman; Scott Stevenson

    2007-01-30

    Renewable Spirits is developing an innovative pilot plant bio-refinery to establish the commercial viability of ehtanol production utilizing a processing waste from citrus juice production. A novel process based on enzymatic hydrolysis of citrus processing waste and fermentation of resulting sugars to ethanol by yeasts was successfully developed in collaboration with a CRADA partner, USDA/ARS Citrus and Subtropical Products Laboratory. The process was also successfully scaled up from laboratory scale to 10,000 gal fermentor level.

  1. Ultrastructure of Slow-Rusting Expression of Wheat to Stripe Rust

    Institute of Scientific and Technical Information of China (English)

    MA Qing; SHANG Hong-sheng; QIANG Lei; XIE Fang-qin; SUN Hui

    2005-01-01

    The ultrastructure of wheat cultivars with slow-rusting resistance expression to the stripe rust, Puccinia striiformis, was studied through TEM. The results show that slow-rusting has the same hypersensitive response characters with the low infection type resistance, but the mesophyll cell necrotized less in number, thereby only partially inhibiting the extension of rust fungus, and the fungus being inhibited and necrosed slighter in degree. Apart from the occurrence of hypersensitiveness, the response of the host cells in slow-rusting wheat cultivars to the infection of fungus also produces structural materials associated with defense reaction, but distinctly less than that in resistant cultivar. Thus, it is suggested that the slow-rusting resistance might have a similar mechanism with the low infection type resistance of race specificity,but with lower intensity.

  2. Systemic resistance in citrus to Tetranychus urticae induced by conspecifics is transmitted by grafting and mediated by mobile amino acids.

    Science.gov (United States)

    Agut, Blas; Gamir, Jordi; Jaques, Josep A; Flors, Victor

    2016-10-01

    Recent research suggests that systemic signalling and communication between roots and leaves plays an important role in plant defence against herbivores. In the present study, we show that the oviposition of the two-spotted spider mite Tetranychus urticae in the systemic leaves of citrus rootstock Citrus aurantium (sour orange) was reduced by 50% when a lower leaf was previously infested with conspecifics. Metabolomic and gene expression analysis of the root efflux revealed a strong accumulation of glutamic acid (Glu) that triggered the expression of the citrus putative glutamate receptor (GRL) in the shoots. Additionally, uninfested sour orange systemic leaves showed increased expression of glutamate receptors and higher amounts of jasmonic acid (JA) and 12-oxo-phytodienoic acid in plants that were previously infested. Glu perception in the shoots induced the JA pathway, which primed LOX-2 gene expression when citrus plants were exposed to a second infestation. The spider mite-susceptible citrus rootstock Cleopatra mandarin (C. unshiu) also expressed systemic resistance, although the resistance was less effective than the resistance in sour orange. Surprisingly, the mobile signal in Cleopatra mandarin was not Glu, which suggests a strong genotype-dependency for systemic signalling in citrus. When the cultivar Clemenules (C. clementina) was grafted onto sour orange, there was a reduction in symptomatic leaves and T. urticae populations compared to the same cultivar grafted onto Cleopatra mandarin. Thus, systemic resistance is transmitted from the roots to the shoots in citrus and is dependent on rootstock resistance.

  3. New slow-rusting leaf rust and stripe rust resistance genes Lr67 and Yr46 in wheat are pleiotropic or closely linked.

    Science.gov (United States)

    Herrera-Foessel, Sybil A; Lagudah, Evans S; Huerta-Espino, Julio; Hayden, Matthew J; Bariana, Harbans S; Singh, Davinder; Singh, Ravi P

    2011-01-01

    The common wheat genotype 'RL6077' was believed to carry the gene Lr34/Yr18 that confers slow-rusting adult plant resistance (APR) to leaf rust and stripe rust but located to a different chromosome through inter-chromosomal reciprocal translocation. However, haplotyping using the cloned Lr34/Yr18 diagnostic marker and the complete sequencing of the gene indicated Lr34/Yr18 is absent in RL6077. We crossed RL6077 with the susceptible parent 'Avocet' and developed F(3), F(4) and F(6) populations from photoperiod-insensitive F(3) lines that were segregating for resistance to leaf rust and stripe rust. The populations were characterized for leaf rust resistance at two Mexican sites, Cd. Obregon during the 2008-2009 and 2009-2010 crop seasons, and El Batan during 2009, and for stripe rust resistance at Toluca, a third Mexican site, during 2009. The F(3) population was also evaluated for stripe rust resistance at Cobbitty, Australia, during 2009. Most lines had correlated responses to leaf rust and stripe rust, indicating that either the same gene, or closely linked genes, confers resistance to both diseases. Molecular mapping using microsatellites led to the identification of five markers (Xgwm165, Xgwm192, Xcfd71, Xbarc98 and Xcfd23) on chromosome 4DL that are associated with this gene(s), with the closest markers being located at 0.4 cM. In a parallel study in Canada using a Thatcher × RL6077 F(3) population, the same leaf rust resistance gene was designated as Lr67 and mapped to the same chromosomal region. The pleiotropic, or closely linked, gene derived from RL6077 that conferred stripe rust resistance in this study was designated as Yr46. The slow-rusting gene(s) Lr67/Yr46 can be utilized in combination with other slow-rusting genes to develop high levels of durable APR to leaf rust and stripe rust in wheat.

  4. Cercosporoid diseases of Citrus.

    Science.gov (United States)

    Huang, Feng; Groenewald, J Z; Zhu, Li; Crous, P W; Li, Hongye

    2015-01-01

    Citrus leaves and fruits exhibiting disease symptoms ranging from greasy spot, yellow spot, small or large brown spot, black dot, and brown dot were sampled from Fujian, Guangdong, Guizhou, Hunan, Jiangxi, Yunnan, Zhejiang provinces and the Guangxi Zhuang Autonomous Region in China. In total 82 isolates representing various cercosporoid genera were isolated from these disease symptoms, which were supplemented with eight Citrus cercosporoid isolates collected from other countries. Based on a morphological and phylogenetic study using sequence data from the nuclear ribosomal DNA's ITS1-5.8S-ITS2 regions (ITS), and partial actin (act), β-tubulin (tub2), 28S nuclear ribosomal RNA (28S rDNA) and translation elongation factor 1-α (tef1) genes, these strains were placed in the following genera: Cercospora, Pallidocercospora, Passalora, Pseudocercospora, Verrucisporota and Zasmidium. All isolates tended to be sterile, except the Zasmidium isolates associated with citrus greasy spot-like symptoms, which subsequently were compared with phylogenetically similar isolates occurring on Citrus and other hosts elsewhere. From these results four Zasmidium species were recognized on Citrus, namely Z. indonesianum on Citrus in Indonesia, Z. fructicola and Z. fructigenum on Citrus in China and Z. citri-griseum, which appears to have a wide host range including Acacia, Citrus, Eucalyptus and Musa, as well as a global distribution.

  5. Certification Programs for Citrus

    Science.gov (United States)

    Citrus certification programs designed to ensure that healthy plants of the highest genetic potential are being planted in the field are the basic building block of an integrated pest management program. Certification programs began for citrus began with the discovery that the diseases were graft t...

  6. Compatibilidade entre acaricidas e fertilizantes foliares em função de diferentes águas no controle do ácaro da leprose dos citros Brevipalpus phoenicis Compatibility between acaricides and foliar fertilizers in different water resources for citrus leprosis mite control Brevipalpus phoenicis

    Directory of Open Access Journals (Sweden)

    Daniel Júnior de Andrade

    2013-03-01

    of foliar fertilizers to an acaricide spray tank is frequently used in citrus crop targeting to reduce application costs. However, its implications are unknown. The aim of this study was evaluating the effect of acaricide spray mixed to foliar fertilizers and also prepared by different water resources for citrus mite control B. phoenicis. Two laboratory experiments were performed in 2009 and 2010, using B. phoenicis infested orange fruits. The first experiment was about three bio essays, which the purpose had been to evaluate the effect of leaf fertilizers and cyhexatin, propargite and acrinathrin acaricides blends into B. phoenicis control. In the second one, leaf fertilizers and propargite and acrinathrin acaricides blends were tested and, in addition, the evaluation of water resources effect into the spray preparation. The results presented that foliar fertilizers as zinc chloride; manganese chloride, urea and the mixture of potassium phosphite + urea + zinc chloride did not affect the cyhexatin, propargite and acrinathrin acaricide action into controlling B. phoenicis infestation. The zinc and manganese chloride mixtures with magnesium sulphate and the addition of potassium phosphite decreased some acaricides efficiency as propargite and acrinathrin, therefore, primarily, they must not be added at the same application. Water resources coming from Itápolis, Pirangi and Pirassununga interfered in the propargite and acrinathrin efficiency over B. phoenicis control, but the Itápolis water resource had shown better results. There was also observed a pH and electrical conductivity variation after some fertilizers addition into the spray water.

  7. Allergens of mites

    Directory of Open Access Journals (Sweden)

    Emilia Siwak

    2014-04-01

    Full Text Available Mite allergens belong to the group of inhalant allergens and represent antigenic substances which are particutlarly important in the pathogenesis of respiratory system diseases and skin diseases. The most common diseases associated with chronic exposure to these aeroallergens include: allergic rhinitis, bronchial asthma and atopic dermatitis. Mite allergens are simple proteins or glycoproteins with different molecular structures and various biochemical functions. The sensitizing capacity of these proteins is connected from their physicochemical properties. Individual allergens perform, among others, the functions of structural proteins, act as enzymes, transport lipids, bind metal ions, and are capable of glycosylation. In addition, mite allergenic proteases degrade proteins of the skin epithelium-resulting in a weakening of its natural protective barrier-and induce the immune response. The proteases also induce the release of pro-inflammatory cytokines: interleukin-4 (IL-4, interleukin 6 (IL-6, interleukin 8 (IL-8, eotaxin, and granulocyte-macrophage colony-stimulating factor-GM-CSF. The article presents the tertiary structure of major and mid-range mite allergens and their classification. Based on literature reports concerning the chemical structure of allergenic proteins, it was emphasized that the structural differences between homologous proteins with allergenic pozoproperties relate to the distribution of amino acid residues on the surface of the molecule. IgE binding affinity and the similarities and differences in the amino acid sequence of the allergens were also the basis for determining cross-reactivity of allergenic proteins. The paper shows an example of this phenomenon, describing the existence of common allergens for various mite species.

  8. [House dust mite allergy].

    Science.gov (United States)

    Carrard, A; Pichler, C

    2012-04-01

    House dust mites can be found all over the world where human beings live independent from the climate. Proteins from the gastrointestinal tract- almost all known as enzymes - are the allergens which induce chronic allergic diseases. The inhalation of small amounts of allergens on a regular base all night leads to a slow beginning of the disease with chronically stuffed nose and an exercise induced asthma which later on persists. House dust mites grow well in a humid climate - this can be in well isolated dwellings or in the tropical climate - and nourish from human skin dander. Scales are found in mattresses, upholstered furniture and carpets. The clinical picture with slowly aggravating complaints leads quite often to a delayed diagnosis, which is accidently done on the occasion of a wider spectrum of allergy skin testing. The beginning of a medical therapy with topical steroids as nasal spray or inhalation leads to a fast relief of the complaints. Although discussed in extensive controversies in the literature - at least in Switzerland with the cold winter and dry climate - the recommendation of house dust mite avoidance measures is given to patients with good clinical results. The frequent ventilation of the dwelling with cold air in winter time cause a lower indoor humidity. Covering encasings on mattresses, pillow, and duvets reduces the possibility of chronic contact with mite allergens as well as the weekly changing the bed linen. Another option of therapy is the specific immunotherapy with extracts of house dust mites showing good results in children and adults. Using recombinant allergens will show a better quality in diagnostic as well as in therapeutic specific immunotherapy.

  9. Abundance of citrus leafminer larvae on citrus and citrus-related germplasm

    Science.gov (United States)

    The citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is a key pest in most citrus growing regions worldwide. Adult citrus leafminers oviposit primarily on young elongating flush of citrus as well as other Rutaceae and some ornamental plants. Larvae feed on the epiderm...

  10. Sealing and anti-corrosive action of tannin rust converters

    Energy Technology Data Exchange (ETDEWEB)

    Gust, J.; Bobrowicz, J. (Building Research Inst., Warsaw (Poland))

    1993-01-01

    A possibility of the application of mercury porosimetry in the investigation on porosity in corrosion products of the carbon steel along with the degree of sealing by the use of tannin rust converters is presented. The effect of the atmospheric humidity on the rust conversion including the time of that conversion on the degree of rust sealing is discussed. The results of the corrosion investigation of carbon steel covered with a layer of the rust converted with tannin-containing agents are presented.

  11. Control of poultry red mites

    DEFF Research Database (Denmark)

    Kilpinen, Ole; Steenberg, Tove

    2008-01-01

    The poultry red mite (PRM), Dermanyssus gallinae, is the most important ectoparasite in European egg production. The mites hide in cracks and crevices in the near vicinity of the resting places of the birds, coming out to feed mainly during the night. Under favourable conditions the population can...... grow rapidly, leading to serious problems. Large mite populations may cause anaemia or even death to the poultry, but also in lower numbers mites may be a nuisance to the birds causing decreased egg production and egg quality. Furthermore, they may have the potential of acting as reservoir...

  12. Epidemiology for hazard rating of white pine blister rust

    Science.gov (United States)

    Eugene P. Van Arsdel; Brian W. Geils; Paul J. Zambino

    2006-01-01

    The ability to assess the potential for a severe infestation of white pine blister rust is an important management tool. Successful hazard rating requires a proper understanding of blister rust epidemiology, including environmental and genetic factors. For the blister rust caused by Cronartium ribicola, climate and meteorology, and the ecology,...

  13. Amino acid uptake in rust fungi.

    Science.gov (United States)

    Struck, Christine

    2015-01-01

    The plant pathogenic rust fungi colonize leaf tissue and feed off their host plants without killing them. Certain economically important species of different genera such as Melampsora, Phakopsora, Puccinia, or Uromyces are extensively studied for resolving the mechanisms of the obligate biotrophy. As obligate parasites rust fungi only can complete their life cycle on living hosts where they grow through the leaf tissue by developing an extended network of intercellular hyphae from which intracellular haustoria are differentiated. Haustoria are involved in key functions of the obligate biotrophic lifestyle: suppressing host defense responses and acquiring nutrients. This review provides a survey of rust fungi nitrogen nutrition with special emphasis on amino acid uptake. A variety of sequences of amino acid transporter genes of rust fungi have been published; however, transport activity of only three in planta highly up-regulated amino acid permeases have been characterized. Functional and immunohistochemical investigations have shown the specificity and localization of these transporters. Sequence data of various genome projects allowed identification of numerous rust amino acid transporter genes. An in silico analysis reveals that these genes can be classified into different transporter families. In addition, genetic and molecular data of amino acid transporters have provided new insights in the corresponding metabolic pathways.

  14. The Big Rust and the Red Queen: Long-Term Perspectives on Coffee Rust Research.

    Science.gov (United States)

    McCook, Stuart; Vandermeer, John

    2015-09-01

    Since 2008, there has been a cluster of outbreaks of the coffee rust (Hemileia vastatrix) across the coffee-growing regions of the Americas, which have been collectively described as the Big Rust. These outbreaks have caused significant hardship to coffee producers and laborers. This essay situates the Big Rust in a broader historical context. Over the past two centuries, coffee farmers have had to deal with the "curse of the Red Queen"-the need to constantly innovate in the face of an increasing range of threats, which includes the rust. Over the 20th century, particularly after World War II, national governments and international organizations developed a network of national, regional, and international coffee research institutions. These public institutions played a vital role in helping coffee farmers manage the rust. Coffee farmers have pursued four major strategies for managing the rust: bioprospecting for resistant coffee plants, breeding resistant coffee plants, chemical control, and agroecological control. Currently, the main challenge for researchers is to develop rust control strategies that are both ecologically and economically viable for coffee farmers, in the context of a volatile, deregulated coffee industry and the emergent challenges of climate change.

  15. Parasitic mites of Surinam XXXIII. Feather mites (Analgoidea)

    NARCIS (Netherlands)

    Černý, V.; Lukoschus, F.S.

    1975-01-01

    The mites listed in the present paper have been collected from July to October 1971 by the junior author and Drs. N. J. J. KOK during their stay in Surinam with financial aid of the Netherlands Foundation for the Advancement of Tropical Research (WOTRO). Mites have been collected occasionally mainly

  16. INFLUENCE OF CITRUS LEPROSIS ON THE MINERAL COMPOSITION OF Citrus sinensis LEAVES

    Directory of Open Access Journals (Sweden)

    N. de L. Nogueira

    1996-05-01

    Full Text Available Citrus leprosis is the main viral disease affecting citrus in Brazil. Viral diseases can affect the mineral composition of citrus leaves, inducing mineral deficiencies. The aim of this work was to verify the influence of citrus leprosis on the mineral composition of citrus leaves, cultivar Pera. Orange seedlings were grown in pots containing sterile soil, and kept under greenhouse conditions. When plants had 15 to 20 leaves, they were infested with the mite Brevipalpus phoenicis, the leprosis vector, collected from infected citrus plants. Other plants were not infested, and were used as the control. Ninety days after infestation, all the infested plants presented leprosis lesions. The six upper leaves of each plant were collected and the determination of macro and micro-elements was performed. Leaves from the infected plants showed lower levels of N and higher levels of Ca, S and Fe, as compared to the control (= 0.05. Both treatments presented similar levels of P, K, Mg, Cu,Mn, Zn and B.A leprose dos citros é uma das principais doenças de citros no Brasil. As doenças causadas por vírus podem afetar a composição mineral de folhas de citros, induzindo deficiências minerais. Este trabalho teve como objetivo analisar a influência da leprose dos citros na composição mineral de folhas de citros, cultivar Pera. Seedlings de laranja foram crescidos em vasos contendo solo estéril e mantidos em casa de vegetação. Plantas com 15 a 20 folhas foram infestadas com ácaro da espécie Brevipalpus phoenicis, vetor da leprose dos citros, provenientes de plantas de citros com sintomas da doença. Outras plantas não foram infestadas, e serviram como controle. Após noventa dias, todas as plantas infestadas apresentavam lesões de leprose. Seis folhas da parte superior de cada planta foram coletadas para determinação dos teores de macro e micronutrientes. As folhas das plantas infectadas apresentaram níveis mais baixos de N e mais elevados de Ca, S

  17. Identification of Green Rust in Groundwater

    DEFF Research Database (Denmark)

    Christiansen, Bo C.; Balic Zunic, Tonci; Dideriksen, Knud

    2009-01-01

    Green rust, a family of Fe(II),Fe(III) layered double hydroxides, is believed to be present in environments close to the Fe(II)/Fe(III) transition zone. Attempts to identify members of this family in nature have proven difficult because the material is oxidized after only a few minutes exposure...... of synthetic GRCO3, the green rust familymemberwherecarbonate and water occupy the interlayer between the iron-hydroxide layers. The method was then tested on samples taken from an artesian well and a deep underground experimental station, both within the Fe(II)/Fe(III) redox zone. In both cases, GRCO3 could...... be identified. Currently, transport models for predicting the behavior of contaminants in groundwater do not include parameters for green rust. This work demonstrates they should....

  18. Citrus diseases with global ramifications including citrus canker and huanglongbing

    Science.gov (United States)

    Although there are a number of diseases that plague citrus production worldwide, two bacterial diseases are particularly problematic. Both are of Asian origin and currently cause severe economic damage: Asiatic citrus canker (ACC) and citrus huanglongbing (HLB). Although ACC has been found in the ...

  19. Leaf Rust of Wheat: Pathogen Biology, Variation and Host Resistance

    Directory of Open Access Journals (Sweden)

    James Kolmer

    2013-01-01

    Full Text Available Rusts are important pathogens of angiosperms and gymnosperms including cereal crops and forest trees. With respect to cereals, rust fungi are among the most important pathogens. Cereal rusts are heteroecious and macrocyclic requiring two taxonomically unrelated hosts to complete a five spore stage life cycle. Cereal rust fungi are highly variable for virulence and molecular polymorphism. Leaf rust, caused by Puccinia triticina is the most common rust of wheat on a worldwide basis. Many different races of P. triticina that vary for virulence to leaf rust resistance genes in wheat differential lines are found annually in the US. Molecular markers have been used to characterize rust populations in the US and worldwide. Highly virulent races of P. triticina are selected by leaf rust resistance genes in the soft red winter wheat, hard red winter wheat and hard red spring wheat cultivars that are grown in different regions of the US. Cultivars that only have race-specific leaf rust resistance genes that are effective in seedling plants lose their effective resistance and become susceptible within a few years of release. Cultivars with combinations of race non-specific resistance genes have remained resistant over a period of years even though races of the leaf rust population have changed constantly.

  20. PHARMACOLOGICAL IMPORTANCE OF CITRUS FRUITS

    Directory of Open Access Journals (Sweden)

    Amita Tomar *, Mridula Mall and Pragya Rai

    2013-01-01

    Full Text Available This paper reviews the pharmacological importance of citrus fruits. Citrus fruits are used for various pharmacological importance. According to literature the citrus fruit possess anti-cancer, antimicrobial, antioxidant, antiulcer, anti-inflammatory, and hypolipidemic and hepatoprotective properties.

  1. Strategic planning for the Florida citrus industry: addressing citrus greening disease

    National Research Council Canada - National Science Library

    2010-01-01

    "Citrus greening, a disease that reduces yield, compromises the flavor, color, and size of citrus fruit and eventually kills the citrus tree, is now present in all 34 Floridian citrus-producing counties...

  2. Plant mites of the Dominican Republic, with a description of a new species of Petrobia (Tetranychina) Wainstein, 1960 (Acari, Prostigmata, Tetranychidae) and a key to the species of this subgenus.

    Science.gov (United States)

    Martínez, Leocadia Sánchez; Flechtmann, Carlos H W; De Moraes, Gilberto J

    2014-08-05

    Fourteen mite species of plant-associated mites of the suborder Prostigmata are reported from the Dominican Republic. Four of these refer to new findings for the country, including Petrobia (Tetranychina) hispaniola n. sp. Sánchez & Flechtmann, described from specimens collected from leaves of Citrus sp. (Rutaceae) and Rosa sp. (Rosaceae). A key for the separation of the world species of Petrobia (Tetranychina) is presented. 

  3. History and Diversity of Citrus leprosis virus Recorded in Herbarium Specimens.

    Science.gov (United States)

    Hartung, John S; Roy, Avijit; Fu, Shimin; Shao, Jonathan; Schneider, William L; Brlansky, Ronald H

    2015-09-01

    Leprosis refers to two diseases of citrus that present similar necrotic local lesions, often surrounded by chlorotic haloes on citrus. Two distinct viruses are associated with this disease, one that produces particles primarily in the nucleus of infected plant cells (Citrus leprosis virus nuclear type [CiLV-N]; Dichorhavirus) and another type that produces particles in the cytoplasm of infected plant cells (Citrus leprosis virus cytoplasmic type [CiLV-C]; Cilevirus). Both forms are transmitted by Brevipalpid mites and have bipartite, single-stranded, RNA genomes. CiLV-C and CiLV-N are present in South and Central America and as far north as parts of Mexico. Although leprosis disease was originally described from Florida, it disappeared from there in the 1960s. The United States Department of Agriculture-Agricultural Research Service maintains preserved citrus specimens identified at inspection stations 50 or more years ago with symptoms of citrus leprosis. We isolated RNA from these samples and performed degradome sequencing. We obtained nearly full-length genome sequences of both a typical CiLV-C isolate intercepted from Argentina in 1967 and a distinct CiLV-N isolate obtained in Florida in 1948. The latter is a novel form of CiLV-N, not known to exist anywhere in the world today. We have also documented the previously unreported presence of CiLV-N in Mexico in the mid-20th century.

  4. Developing blister rust resistance in white pines

    Science.gov (United States)

    Bohun B. Kinloch Jr.

    2000-01-01

    After a century since introduction to North America from Europe, white pine blister rust, caused by Cronartium ribicola J.C. Fisch., is recognized as one of the catastrophic plant disease epidemics in history. It has not yet stabilized and continues to spread and intensify. Its nine native white pine hosts comprise major timber producers, important...

  5. Zoete rust : een muzikale soap-detective

    NARCIS (Netherlands)

    Maas, P.

    1989-01-01

    De komedie' Zoete Rust' werd geschreven in opdracht van Theater de Tobbe in Voorburg . Naast de circa 120 professionele voorstellingen die elk seizoen in dit theater plaats vinden, organiseert De Tobbe een maal per laar een eigen theaterproduktie, die wordt gespeeld door het Tobbe-toneel, een ad-hoc

  6. Epidemiology of bean rust in Ethiopia

    NARCIS (Netherlands)

    Habtu, A.

    1994-01-01

    Field and greenhouse experiments were conducted to study the epidemiology of rust ( Uromyces appendiculatus ) on beans ( Phaseolus vulgaris L.) in Ethiopia. The experiments were conducted under low input conditions reflecting

  7. Antioxidant activity of Citrus fruits.

    Science.gov (United States)

    Zou, Zhuo; Xi, Wanpeng; Hu, Yan; Nie, Chao; Zhou, Zhiqin

    2016-04-01

    Citrus is well-known for its nutrition and health-promotion values. This reputation is derived from the studies on the biological functions of phytochemicals in Citrus fruits and their derived products in the past decades. In recent years, the antioxidant activity of Citrus fruits and their roles in the prevention and treatment of various human chronic and degenerative diseases have attracted more and more attention. Citrus fruits are suggested to be a good source of dietary antioxidants. To have a better understanding of the mechanism underlying the antioxidant activity of Citrus fruits, we reviewed a study on the antioxidant activity of the phytochemicals in Citrus fruits, introduced methods for antioxidant activity evaluation, discussed the factors which influence the antioxidant activity of Citrus fruits, and summarized the underlying mechanism of action. Some suggestions for future study were also presented.

  8. Current status of the Citrus leprosis virus (CiLV -C and its vector Brevipalpus phoenicis (Geijskes

    Directory of Open Access Journals (Sweden)

    Guillermo León M

    2012-08-01

    Full Text Available The Citrus leprosis virus CiLV-C is a quarantine disease of economic importance. Over the past 15 years, this disease has spread to several countries of Central and South America. Colombia has about 45,000 hectares of citrus planted with an annual production of 750,000 tonnes. The CiLV-C has only been detected in the departments of Meta, Casanare and recently Tolima. Meta has 4,300 hectares representing 10% of the national cultivated area, and Casanare, where CiLV-C appeared in 2004, has no more than 500 ha planted with citrus. The presence of the Citrus leprosis virus in Colombia could affect the international market for citrus, other crops and ornamental plants with the United States and other countries without the disease. The false spider mite Brevipalpus phoenicis (Geijskes (Acari: Tenuipalpidae is the main vector of the CiLV-C. Disease management is based on control programs of the vector and diminishing host plants. Chemical mite control is expensive, wasteful and generates resistance to different acaricides. This paper provides basic information on CiLV-C and its vector, advances in diagnosis and methods to control the disease and prevention of its spread

  9. Control of poultry red mites

    DEFF Research Database (Denmark)

    Kilpinen, Ole; Steenberg, Tove

    2008-01-01

    The poultry red mite (PRM), Dermanyssus gallinae, is the most important ectoparasite in European egg production. The mites hide in cracks and crevices in the near vicinity of the resting places of the birds, coming out to feed mainly during the night. Under favourable conditions the population can...... grow rapidly, leading to serious problems. Large mite populations may cause anaemia or even death to the poultry, but also in lower numbers mites may be a nuisance to the birds causing decreased egg production and egg quality. Furthermore, they may have the potential of acting as reservoir....../carriers for various micro-organisms e.g. Salmonella. In SAFEHOUSE, an EU-project running from 2006-2009, partners from 11 European countries aim at developing new methods for prevention and control of Salmonella in egg production systems with particular focus on the transition to enriched cages in the EU. Enriched...

  10. Cercosporoid diseases of Citrus

    NARCIS (Netherlands)

    Huang, Feng; Groenewald, J.Z.; Zhu, Li; Crous, P.W.; Li, Hongye

    2015-01-01

    Citrus leaves and fruits exhibiting disease symptoms ranging from greasy spot, yellow spot, small or large brown spot, black dot, and brown dot were sampled from Fujian, Guangdong, Guizhou, Hunan, Jiangxi, Yunnan, Zhejiang provinces and the Guangxi Zhuang Autonomous Region in China. In total 82 isol

  11. [House dust mites and their allergens].

    Science.gov (United States)

    Bessot, J-C; Pauli, G

    2011-02-01

    The taxonomy, anatomy, life cycle and ecology of Pyroglyphidae mites and storage mites (Acaridae, Glycyphagidae, B. tropicalis) are described. Pyroglyphidae and storage mites have similar morphologies: they are octopods, with characteristic gnathosoma and sensory hairs. Salivary glands and the mid gut produce most of the allergens excreted, which are enzymatic proteins. Biological cycles and development are similar, although fecundity is superior in storage mites compared to the Pyroglyphides. Relative humidity is the main parameter, which regulates mite development, with a higher degree of temperature and humidity required for storage mites. Bedding is the ecological niche of Pyroglyphidae, which feed on human skin. Moulds and food products are the storage mite biotope from which they spread in the dwelling. Initially considered as rural mites, storage mites are also present in urban dwellings. B. tropicalis, in tropical regions is a true domestic mite. Because of this, it is justified to denominate Pyroglyphidae "house dust mites" and storage mites "domestic mites". In addition to the respiratory allergic symptoms, the storage mites can also cause occupational contact dermatoses.

  12. Potential Nutritional Benefits of Current Citrus Consumption

    Directory of Open Access Journals (Sweden)

    Tami Turner

    2013-03-01

    Full Text Available Citrus contains nutrients and phytochemicals that may be beneficial for health. We collected citrus production and consumption data and estimated the amount of these compounds that are consumed. We then compared the amounts of citrus and citrus-derived compounds used in studies that suggest a health benefit to the amounts typically found in citrus. Data is scarce, but suggests that citrus consumption might improve indices of antioxidant status, and possibly cardiovascular health and insulin sensitivity.

  13. Optimal alarm system applied in coffee rust

    Directory of Open Access Journals (Sweden)

    Luciene Resende Gonçalves

    2014-02-01

    Full Text Available Alarm systems have very great utility in detecting and warning of catastrophes. This methodology was applied via TARSO model with Bayesian estimation, serving as a forecasting mechanism for coffee rust disease. The coffee culture is very susceptible to this disease causing several records of incidence in most cultivated crops. Researches involving this limiting factor for production are intense and frequent, indicating environmental factors as responsible for the epidemics spread, which does not occur if these factors are not favorable. The fitting type used by the a posteriori probability, allows the system to be updated each time point. The methodology was applied to the rust index series in the presence of the average temperature series. Thus, it is possible to verify the alarm resulted or in a high catastrophe detection in points at which the catastrophe has not occurred, or in the low detections if the point was already in the catastrophe state.

  14. Climate change impacts on coffee rust disease

    Science.gov (United States)

    Alfonsi, W. M. V.; Koga-Vicente, A.; Pinto, H. S.; Alfonsi, E. L., Sr.; Coltri, P. P.; Zullo, J., Jr.; Patricio, F. R.; Avila, A. M. H. D.; Gonçalves, R. R. D. V.

    2016-12-01

    Changes in climate conditions and in extreme weather events may affect the food security due to impacts in agricultural production. Despite several researches have been assessed the impacts of extremes in yield crops in climate change scenarios, there is the need to consider the effects in pests and diseases which increase losses in the sector. Coffee Arabica is an important commodity in world and plays a key role in Brazilian agricultural exports. Although the coffee crop has a world highlight, its yield is affected by several factors abiotic or biotic. The weather as well pests and diseases directly influence the development and coffee crop yield. These problems may cause serious damage with significant economic impacts. The coffee rust, caused by the fungus Hemileia vastarix,is among the diseases of greatest impact for the crop. The disease emerged in Brazil in the 70s and is widely spread in all producing regions of coffee in Brazil, and in the world. Regions with favorable weather conditions for the pathogen may exhibit losses ranging from 30% to 50% of the total grain production. The evaluation of extreme weather events of coffee rust disease in futures scenarios was carried out using the climatic data from CMIP5 models, data field of coffee rust disease incidence and, incubation period simulation data for Brazilian municipalities. Two Regional Climate Models were selected, Eta-HadGEM2-ES and Eta-MIROC5, and the Representative Concentration Pathways 8.5 w/m2 was adopted. The outcomes pointed out that in these scenarios the period of incubation tends to decrease affecting the coffee rust disease incidence, which tends to increase. Nevertheless, the changing in average trends tends to benefit the reproduction of the pathogen. Once the temperature threshold for the disease reaches the adverse conditions it may be unfavorable for the incidence.

  15. If I Rest,I Rust

    Institute of Scientific and Technical Information of China (English)

    Orison; Swett; Marden; 陆小丫

    2003-01-01

    选注者言:流水不腐,户枢不蠹。人的才干又何尝不是如此?If I Rest,I Rust 的标题就让我们玩味再三!思之再三,权译:吾“休”则“锈”。宝剑锋从磨砺出, 梅花香自苦寒来。此言非虚!

  16. Infochemical use by predatory mites of the cassava green mite in a multitrophic context

    NARCIS (Netherlands)

    Gnanvossou, D.

    2002-01-01

    This thesis describes research on multitrophic interactions in a system consisting of (1) cassava plants ( Manihot esculenta ), (2) three herbivorous mites, i.e. the cassava green mite Mononychellus tanajoa, the red spider mite Oligonychus gossypii and the two-spotted spider mite Tetranychus urticae

  17. Human Demodex Mite: The Versatile Mite of Dermatological Importance

    Directory of Open Access Journals (Sweden)

    Parvaiz Anwar Rather

    2014-01-01

    Full Text Available Demodex mite is an obligate human ecto-parasite found in or near the pilo-sebaceous units. Demodex folliculorum and Demodex brevis are two species typically found on humans. Demodex infestation usually remains asymptomatic and may have a pathogenic role only when present in high densities and also because of immune imbalance. All cutaneous diseases caused by Demodex mites are clubbed under the term demodicosis or demodicidosis, which can be an etiological factor of or resemble a variety of dermatoses. Therefore, a high index of clinical suspicion about the etiological role of Demodex in various dermatoses can help in early diagnosis and appropriate, timely, and cost effective management.

  18. Human demodex mite: the versatile mite of dermatological importance.

    Science.gov (United States)

    Rather, Parvaiz Anwar; Hassan, Iffat

    2014-01-01

    Demodex mite is an obligate human ecto-parasite found in or near the pilo-sebaceous units. Demodex folliculorum and Demodex brevis are two species typically found on humans. Demodex infestation usually remains asymptomatic and may have a pathogenic role only when present in high densities and also because of immune imbalance. All cutaneous diseases caused by Demodex mites are clubbed under the term demodicosis or demodicidosis, which can be an etiological factor of or resemble a variety of dermatoses. Therefore, a high index of clinical suspicion about the etiological role of Demodex in various dermatoses can help in early diagnosis and appropriate, timely, and cost effective management.

  19. 小麦MITE扩增体系的建立%Establishment of MITE Amplification System in the Wheat Study

    Institute of Scientific and Technical Information of China (English)

    谢欢; 杨文香; 彭巧慧; 赵丽娟; 刘力伟; 张娜; 刘大群

    2014-01-01

    Thatcher and 23 of wheat leaf rust resistance near isogenic lines in Thatcher background were chosen as materials in this experiment. Research on the establishment of MITE amplification system was carried out. 27 of the 56 primer pairs were amplified stably,reaction system and different annealing temperature of primers were con-firmed for amplification of MITE ( Miniature inverted repeat transposable elements) .%以Thatcher及23个以Thatcher为遗传背景的小麦抗叶锈病近等基因系为材料,开展了MITE扩增体系的建立研究,获得了适合小麦MITE分子标记的扩增体系及不同引物的退火温度,所用56对引物有27对获得稳定扩增。

  20. Incomplete resistance to coffee leaf rust (Hemileia vastatrix)

    NARCIS (Netherlands)

    Eskes, T.K.A.B.

    1983-01-01

    Incomplete resistance to coffee leaf rust ( Hemileia vastatrix ) may be of value in obtaining durable resistance, which is of great importance for the perennial coffee crop. Methods were developed to assess incomplete resistance to coffee leaf rust by using illustrated scales ranging from 0 t

  1. Incomplete resistance to coffee leaf rust (Hemileia vastatrix)

    NARCIS (Netherlands)

    Eskes, A.B.

    1983-01-01

    Incomplete resistance to coffee leaf rust ( Hemileia vastatrix ) may be of value in obtaining durable resistance, which is of great importance for the perennial coffee crop. Methods were developed to assess incomplete resistance to coffee leaf rust by using illustrated scales

  2. White pines, blister rust, and management in the Southwest

    Science.gov (United States)

    D. A. Conklin; M Fairweather; D Ryerson; B Geils; D Vogler

    2009-01-01

    White pines in New Mexico and Arizona are threatened by the invasive disease white pine blister rust, Cronartium ribicola. Blister rust is already causing severe damage to a large population of southwestern white pine in the Sacramento Mountains of southern New Mexico. Recent detection in northern and western New Mexico suggests that a major expansion of the...

  3. Interacting genes in the pine-fusiform rust forest pathosystem

    Science.gov (United States)

    H.V. Amerson; T.L. Kubisiak; S.A. Garcia; G.C. Kuhlman; C.D. Nelson; S.E. McKeand; T.J. Mullin; B. Li

    2005-01-01

    Fusiform rust (FR) disease of pines, caused by Cronartium quercuum f.sp. fusiforme (Cqf), is the most destructive disease in pine plantations of the southern U. S. The NCSU fusiform rust program, in conjunction with the USDA-Forest Service in Saucier, MS and Athens, GA, has research underway to elucidate some of the genetic interactions in this...

  4. Stem rust spores elicit rapid RPG1 phosphorylation

    Science.gov (United States)

    Stem rust threatens cereal production worldwide. Understanding the mechanism by which durable resistance genes, such as Rpg1, function is critical. We show that the RPG1 protein is phosphorylated within 5 min by exposure to spores from avirulent but not virulent races of stem rust. Transgenic mutant...

  5. First Report of Orange Rust of Sugarcane Caused by Puccinia kuehnii in Ivory Coast and Cameroon

    Science.gov (United States)

    Orange rust of sugarcane caused by Puccinia kuehnii was detected in Florida in 2007. It was hypothesized that the pathogen originated from Africa because brown rust of sugarcane (syn. common rust) was introduced to the Western Hemisphere from Africa. Requests for rust infected sugarcane samples were...

  6. The potential for citrus cryotherapy

    Science.gov (United States)

    Citrus collections of pathogen-free plants are needed for breeding, research, and distribution to the user community. The Citrus Research Board funded research project “Development of cryotherapy as an improved method of eliminating graft transmissible pathogens in Citrus” sought to use cryotherapy,...

  7. Introgression of leaf rust and stripe rust resistance from Sharon goatgrass (Aegilops sharonensis Eig) into bread wheat (Triticum aestivum L.)

    Science.gov (United States)

    Leaf rust and stripe rust are devastating wheat diseases, causing significant yield losses in many regions of the world. The use of resistant varieties is the most efficient way to protect wheat crops from these diseases. Sharon goatgrass (Aegilops sharonensis or AES), which is a diploid wild relati...

  8. In vitro and in vivo effect of Citrus limon essential oil against sarcoptic mange in rabbits.

    Science.gov (United States)

    Aboelhadid, S M; Mahrous, Lilian N; Hashem, Shimaa A; Abdel-Kafy, E M; Miller, Robert J

    2016-08-01

    The effect of lemon oil (Citrus limon) on Sarcoptes scabiei var. cuniculi was evaluated in vitro and in vivo. The mite samples were collected from naturally infected rabbits. The lemon oil was prepared in six concentrations by dilution with distilled water (2.5, 5, 10, 20, 50, and 100 %). In vitro application was done in five replicates for each concentration in petri dishes in the laboratory. The treated mites were observed at 1, 12, and 24 h post application (PA) for lemon oil effect. In addition, oxidative stress profile was evaluated for the treated mite. Dependent on in vitro results, 20 % lemon oil was used in vivo trial. Twenty-four naturally infected rabbits were divided into three groups of eight: 20 % lemon oil, deltamethrin, and untreated control. The infected parts of rabbits were treated topically once a week for four successive weeks. In vitro application results showed that lemon oil 10 and 20 % diluted in water caused mortality to 100 % of mites after 24 h PA. The oxidative stress profile revealed that mites treated with 20 % lemon oil had significantly (P < 0.05) higher hydrogen peroxide and malondialdehyde when compared with mites treated with deltamethrin or distilled water. In vivo application of 20 % lemon oil on naturally infected rabbits showed complete recovery from clinical signs, absence of mite in microscopic examination from the second week of treatment. In addition, productive performance was significantly better than infected untreated group. Also, the treated tissue showed stoppage of scale formation and hair growth faster than deltamethrin-treated rabbits. Consequently, lemon oil has remarkable miticidal activity in vitro and in vivo applications.

  9. 76 FR 8603 - Citrus Seed Imports; Citrus Greening and Citrus Variegated Chlorosis

    Science.gov (United States)

    2011-02-15

    ... propagative seed of several Rutaceae (citrus family) genera from certain countries where citrus greening or... Rutaceae may be a pathway for the introduction of those diseases. The interim rule was necessary in order...), we amended the regulations to prohibit the importation of propagative seed of several...

  10. Wheat Production and Wheat Rust Management in Canada

    Institute of Scientific and Technical Information of China (English)

    Xue Allen G; Chi Dawn T; Zhang Shu-zhen; Li Zuo-fu

    2012-01-01

    Wheat is Canada's the largest crop with most of the production in the western Canadian Prairie Provinces of Manitoba, Saskatchewan and Alberta. There were approximately 10 million (M) hectares (hm2) seeded to wheat in Canada, including 7 M hm2 of hexaploid spring wheat (Triticum aestivum L.), 2 M hm2 of durum wheat (T. turgidum L. ssp. durum (Desf.) Husn.), and 1 M hm2 of winter wheat (T. aestivum). Within hexaploid wheat there has been diversification into a number of market classes based on different end-use quality criteria. The predominant spring bread wheat class has been the Canada Western Red Spring (CWRS) class. Historically, the disease of major concern in wheat was stem rust, caused by Puccinia graminis f. sp. tritici. The first significant stem rust resistant cultivar in Canada was Thatcher, grown extensively from 1939 until the early 1970s. Thatcher, however, was very susceptible to leaf rust, caused by Puccinia triticina. Over years, improved resistance to both stem and leaf rust was achieved with the release of cultivars with additional genes for resistance, primarily Sr2, Sr6, Sr7a, Sr9b, Lr13, Lr14a, Lr16, and Lr34. The genetic resistance has adequately controlled stem rust but leaf rust continues to cause significant loss, partially due to changes in the P. triticina population which reduced the effectiveness of resistance genes such as Lr13 and Lr16. Stripe rust on wheat, caused by Puccinia striiformis f. sp. tritici, was historically a problem under irrigation in southern Alberta, but since 2000, it has been found annually in the central Canadian prairies and southern Ontario. The genetic basis of resistance to stripe rust in most Canadian wheat cultivars has not been determined, although Yr18 provides partial resistance in many cultivars. In the future, other rust diseases, such as wheat stripe rust, or highly virulent new pathotypes of current rust pathogens, such as P. graminis f. sp. tritici race Ug-99, may pose

  11. Rust fungi on Annonaceae: the genus Sphaerophragmium.

    Science.gov (United States)

    Beenken, Ludwig; Berndt, Reinhard

    2010-01-01

    Seven species of the rust genus Sphaerophragmium occur on members of the tropical plant family Annonaceae. Uropyxis gerstneri is recombined to S. gerstneri. A new species, S. xylopiae, is described from Xylopia acutiflora. The host plant of S. boanense is identified as Mitrella sp. Sphaerophragmium pulchrum is transferred to Dicheirinia. The anatomy of telia with teliospores and parasitizing mycelium is described and illustrated in detail. A new type of M-haustorium, which emanates laterally from intracellular hypha, is detected in S. monodorae. An identification key is given.

  12. Why do Varroa mites prefer nurse bees?

    Science.gov (United States)

    Xie, Xianbing; Huang, Zachary Y.; Zeng, Zhijiang

    2016-01-01

    The Varroa mite, Varroa destructor, is an acarine ecto-parasite on Apis mellifera. It is the worst pest of Apis mellifera, yet its reproductive biology on the host is not well understood. In particular, the significance of the phoretic stage, when mites feed on adult bees for a few days, is not clear. In addition, it is not clear whether the preference of mites for nurses observed in the laboratory also happens inside real colonies. We show that Varroa mites prefer nurses over both newly emerged bees and forgers in a colony setting. We then determined the mechanism behind this preference. We show that this preference maximizes Varroa fitness, although due to the fact that each mite must find a second host (a pupa) to reproduce, the fitness benefit to the mites is not immediate but delayed. Our results suggest that the Varroa mite is a highly adapted parasite for honey bees. PMID:27302644

  13. House Dust Mite Respiratory Allergy

    DEFF Research Database (Denmark)

    Calderón, Moisés A; Kleine-Tebbe, Jörg; Linneberg, Allan

    2015-01-01

    Although house dust mite (HDM) allergy is a major cause of respiratory allergic disease, specific diagnosis and effective treatment both present unresolved challenges. Guidelines for the treatment of allergic rhinitis and asthma are well supported in the literature, but specific evidence on the e...

  14. Honey Bees: Sweetness and Mites

    Science.gov (United States)

    Honey bee colony losses have been in the news lately and the potential reasons for these losses have taken up much space in the news media. In order to clarify what role mites play in the current loss (2006-2007) of bee colonies, called Colony Collapse Disorder, a better understanding of what a mit...

  15. House dust mites, our intimate associates.

    Science.gov (United States)

    Nadchatram, M

    2005-06-01

    House dust mites have lived in human contact from time immemorial. Human dander or dead skin constitutes the major organic component of the house dust ecosystem. Because the mites feed on dander, dust mites and human association will continue to co-exist as part of our environment. Efficient house-keeping practice is the best form of control to reduce infestation. However, special precautions are important when individuals are susceptible or sensitive to dust mites. House dust mites are responsible for causing asthma, rhinitis and contact dermatitis. The respiratory allergies are caused by the inhalation of dead or live mites, their faecal matter or other byproducts. Immune factors are of paramount importance in the development of dust related or mite induced respiratory diseases. House dust mites were found in some 1,000 samples of dust taken from approximately 330 dwellings in Peninsular Malaysia and Singapore. Mattresses, carpets, corners of a bedroom, and floor beneath the bed are favourable dust mite habitats. The incriminating species based on studies here and elsewhere, as well as many other species of dust mites of unknown etiological importance are widely distributed in Malaysian homes. Density of dust mites in Malaysia and Singapore is greater than in temperate countries. Prevention and control measures with reference to subjects sensitive to dust mite allergies, including chemical control described in studies conducted in Europe and America are discussed. However, a cost free and most practical way to remove mites, their faecal matter and other products is to resort to sunning the bedding and carpets to kill the living mites, and then beaten and brushed to remove the dust and other components.

  16. Nonhost resistance to rust pathogens – a continuation of continua

    Directory of Open Access Journals (Sweden)

    Jan eBettgenhaeuser

    2014-12-01

    Full Text Available The rust fungi (order: Pucciniales are a group of widely distributed fungal plant pathogens, which can infect representatives of all vascular plant groups. Rust diseases significantly impact several crop species and considerable research focuses on understanding the basis of host specificity and nonhost resistance. Like many pathogens, rust fungi vary considerably in the number of hosts they can infect, such as wheat leaf rust (Puccinia triticina, which can only infect species in the genera Triticum and Aegilops, whereas Asian soybean rust (Phakopsora pachyrhizi is known to infect over 95 species from over 42 genera. A greater understanding of the genetic basis determining host range has the potential to identify sources of durable resistance for agronomically important crops. Delimiting the boundary between host and nonhost has been complicated by the quantitative nature of phenotypes in the transition between these two states. Plant-pathogen interactions in this intermediate state are characterized either by (1 the majority of accessions of a species being resistant to the rust or (2 the rust only being able to partially complete key components of its life cycle. This leads to a continuum of disease phenotypes in the interaction with different plant species, observed as a range from compatibility (host to complete immunity within a species (nonhost. In this review we will highlight how the quantitative nature of disease resistance in these intermediate interactions is caused by a continuum of defense barriers, which a pathogen needs to overcome for successfully establishing itself in the host. To illustrate continua as this underlying principle, we will discuss the advances that have been made in studying nonhost resistance towards rust pathogens, particularly cereal rust pathogens.

  17. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Dideriksen, K.; Katz, A.;

    2014-01-01

    Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain...... with water showed that Na+ and K+ were structurally fixed in the interlayer, whereas Rb+ and Cs+ could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both...

  18. A review of soybean rust from a South African perspective

    Directory of Open Access Journals (Sweden)

    J. Antony Jarvie

    2010-01-01

    Full Text Available This review article describes the nature of the soybean rust pathogen, its interaction with the soybean host and documents some of the history of soybean rust in South Africa. Soybean rust has affected soybean cropping in parts of South Africa since 2001. The disease causes leaf lesions, which may progress to premature defoliation and ultimately result in grain yield loss in susceptible soybean genotypes. Chemical control measures have been successfully employed to limit commercial yield losses in South Africa; however, controlling the effects of this disease through host-resistance or tolerance mechanisms remains a long-term goal.

  19. In vitro efficacy of ByeMite and Mite-Stop on developmental stages of the red chicken mite Dermanyssus gallinae.

    Science.gov (United States)

    Abdel-Ghaffar, Fathy; Semmler, Margit; Al-Rasheid, Khaled; Mehlhorn, Heinz

    2009-10-01

    The present in vitro study shows the efficacy of two antimite products (ByeMite = phoxim, Mite-Stop = neem seed extract) against all developing stages of the important red chicken mite Dermanyssus gallinae (obtained at two farms in France and Germany). While permanent contact with the active compound led to an efficacy of 100% in the case of Mite-Stop on mites in both farms, there was only a 96.2% killing effect of ByeMite on the mites of the French farm. Even short contacts of only 4 s killed 100% of mites in the case of Mite-Stop at the French farm and only 84.5% in the German farm. ByeMite, on the other hand, killed only 27.8% (Germany) and 30% (France) when mites got the chance to escape from the treated grounds to untreated ones. When using only the half doses of both products, Mite-Stop(R) still reached, after permanent contact, 100% activity on the German farm and 98.2% in France, while ByeMite killed 93.8% (Germany) and 90.6% (France). Short contact to half doses of course reduced the activity of both products (Mite-Stop = 59.3% in France, 22.1% in Germany; ByeMite = 28.8% in France, 18.8% in Germany). With respect to the fumigant activity of the products, the strains of D. gallinae reacted differently. While Mite-Stop(R) showed a clear fumigant activity in the case of the German mites, this product did not affect the French mites by air distribution, neither did ByeMite in both cases. Therefore, mites have to come in contact with both products. Against Mite-Stop, there was apparently no resistance and low doses have high efficacy after even short contacts, which regularly occur in a treated stable, where mites have the chance to leave treated places to untreated hidden spots.

  20. Study of Demodex mites: Challenges and Solutions.

    Science.gov (United States)

    Lacey, N; Russell-Hallinan, A; Powell, F C

    2016-05-01

    Demodex mites are the largest and most complex organisms of the skin microflora. How they interact with the innate and adaptive immune systems is unknown. Their potential to have a pathogenic role in the causation of human skin disorders causes continued speculation. With growing interest in the microflora of human skin and its relevance to cutaneous health, the role of Demodex mites needs to be better understood. The main challenges facing scientists investigating the role of these organisms and possible solutions are reviewed under the following headings: (1) Determining the mite population in skin, (2) Transporting, extracting and imaging live mites, (3) Maintaining mites viable ex vivo and (4) Establishing methods to determine the immune response to Demodex mites and their internal contents.

  1. SPATIAL DISTRIBUTION AND SEQUENTIAL SAMPLING OF Brevipalpus phoenicis IN CITRUS

    Directory of Open Access Journals (Sweden)

    WALTER MALDONADO JR

    Full Text Available ABSTRACT Among the pests of citrus, one of the most important is the red and black flat mite Brevipalpus phoenicis (Geijskes, which transmits the Citrus leprosis virus C (CiLV-C.When a rational pest control plan is adopted, it is important to determine the correct timing for carrying out the control plan. Making this decision demands constant follow-up of the culture through periodic sampling where knowledge about the spatial distribution of the pest is a fundamental part to improve sampling and control decisions. The objective of this work was to study the spatial distribution pattern and build a sequential sampling plan for the pest. The data used were gathered from two blocks of Valencia sweet orange on a farm in São Paulo State, Brazil, by 40 inspectors trained for the data collection. The following aggregation indices were calculated: variance/ mean ratio, Morisita index, Green’s coefficient, and k parameter of the negative binomial distribution. The data were tested for fit with Poisson and negative binomial distributions using the chi-square goodness of fit test. The sequential sampling was developed using Wald’s Sequential Probability Ratio Test and validated through simulations. We concluded that the spatial distribution of B. phoenicis is aggregated, its behavior best fitted to the negative binomial distribution and we built and validated a sequential sampling plan for control decision-making.

  2. Recombinant house dust mite allergens

    OpenAIRE

    2013-01-01

    House dust mites (HDM) are a globally important source of allergen responsible for the sensitization of more than 50% of allergic patients. Specific immunotherapy with HDM extracts is effective but allergen extracts cannot be fully standardized and severe side-effects can occur during the protracted course of treatment. The introduction of molecular biological techniques into allergy research allowed the indentification of more than 20 groups of HDM allergens. Recombinant HDM allergens can be...

  3. Ecology of Postlarval Stages of Chigger Mites.

    Science.gov (United States)

    1985-12-05

    reason is the large variance inherent in soil arthropod data (Hughes 1962, Nef 1962). Owing to the low numbers of astigmatid mites collected in this study...from positive and negative chigger sites showed that one species of astigmatid mite , "Acaridae sp. II", had significantly higher populations at...AD-A162 524 ECOLOGY OF POSTLRRVAL STAGES OF CHIGGER MITES (U) GEORGIA UNIV ATHENS DEPT OF ENTOMOLOGY CROSSLEY ET AL 85 DEC 85 N88814486-C-0547 UCASFED

  4. [Control strategies against Varroa mites].

    Science.gov (United States)

    Lodesani, M

    2004-06-01

    In many cases, the easiest way to control a pest or a pathogen is to resort to chemical treatments. In the short period this option is often the most convenient economically and usually does not require refined knowledge of the biology of the pest. Many efforts have been directed to develop chemical treatments against Varroa destructor Anderson & Trueman. Nowadays, product based on organic acids, essential oils, pyrethroids, organophosphate, and formamidine are available. Resistance is serious problem in the chemotherapy of parasites and pathogens of the honeybee. High-level resistance to several active substances (the pyrethroids acrinathrin, flumethrin, fluvalinate; the organophosphate coumaphos; the formamidine amitraz) was detected with laboratory assays in different varroa populations and caused failure of the control in the field. At the end of the '80s, products based on pyrethroids, very effective against the mite, but without any appreciable side effect on bees, became available. Resistance to fluvalinate in Italy and later in other countries caused serious damage to beekeeping; early detection was crucial to reduce losses. The problem of developing suitable treatments was difficult in the case of the varroa mite because most substances active against V. destructor have unacceptable side effects on bees. The idea that the mite could be controlled indefinitely with these strategies began to gain ground.

  5. Infochemical use by predatory mites of the cassava green mite in a multitrophic context

    NARCIS (Netherlands)

    Gnanvossou, D.

    2002-01-01

    This thesis describes research on multitrophic interactions in a system consisting of (1) cassava plants ( Manihot esculenta ), (2) three herbivorous mites, i.e. the cassava green mite Mononychellus tanajoa, the red spider mite Oligonychus

  6. House dust mite control measures for asthma

    DEFF Research Database (Denmark)

    Gøtzsche, Peter C.; Johansen, Helle Krogh

    2008-01-01

    antigens in the homes of people with mite-sensitive asthma. SEARCH STRATEGY: PubMed and The Cochrane Library (last searches Nov 2007), reference lists. SELECTION CRITERIA: Randomised trials of mite control measures vs placebo or no treatment in people with asthma known to be sensitive to house dust mites.......07), or in medication usage (standardised mean difference -0.06, 95% CI -0.18 to 0.07). AUTHORS' CONCLUSIONS: Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot be recommended. It is doubtful whether further studies, similar to the ones in our review, are worthwhile. If other...

  7. Corrosion in drinking water pipes: the importance of green rusts.

    Science.gov (United States)

    Swietlik, Joanna; Raczyk-Stanisławiak, Urszula; Piszora, Paweł; Nawrocki, Jacek

    2012-01-01

    Complex crystallographic composition of the corrosion products is studied by diffraction methods and results obtained after different pre-treatment of samples are compared. The green rusts are found to be much more abundant in corrosion scales than it has been assumed so far. The characteristic and crystallographic composition of corrosion scales and deposits suspended in steady waters were analyzed by X-ray diffraction (XRD). The necessity of the examination of corrosion products in the wet conditions is indicated. The drying of the samples before analysis is shown to substantially change the crystallographic phases originally present in corrosion products. On sample drying the unstable green rusts is converted into more stable phases such as goethite and lepidocrocite, while the content of magnetite and siderite decreases. Three types of green rusts in wet materials sampled from tubercles are identified. Unexpectedly, in almost all corrosion scale samples significant amounts of the least stable green rust in chloride form was detected. Analysis of corrosion products suspended in steady water, which remained between tubercles and possibly in their interiors, revealed complex crystallographic composition of the sampled material. Goethite, lepidocrocite and magnetite as well as low amounts of siderite and quartz were present in all samples. Six different forms of green rusts were identified in the deposits separated from steady waters and the most abundant was carbonate green rust GR(CO(3)(2-))(I).

  8. Reaction of peanut cultivars to late leafspot and rust

    Directory of Open Access Journals (Sweden)

    Nimitr Vorasoot

    2003-05-01

    Full Text Available Late leafspot caused by Phaeoisariopsis personata (Berk. & M.A. Curtis van Arx and rust caused by Puccinia arachidis Speg. are among the most serious diseases of peanut. Although fungicide application is effective in controlling the diseases, its high cost is considered uneconomical in many developing countries. In this situation, the use of resistant cultivars offers a better alternative. The objective of this study was to evaluate seven peanut cultivars for their resistances to late leafspot and rust. Peanut cultivars were planted in a randomized complete block design (RCBD with 4 replications at Khon Kaen University Experimental Farm. Natural infection of late leafspot and rust were allowed. Disease score, sporulation index and lesion number per 100 cm2 of leaf area were recorded as the resistance parameters of both diseases. Pod yield, seed yield, shelling percentage, pod number per plant and pod length were also measured. NC 17135 was the most resistant to late leafspot and moderately resistant to rust. NC 17090 was the most resistant to rust but susceptible to late leafspot. NC 17135 and NC 17090 should be recommended as sources of late leafspot and rust resistance, respectively. The two Thai released cultivars, Tainan 9 and Lampang were highly susceptible to both diseases.

  9. Evaluation of Antibacterial Activities of Citrus limon, Citrus reticulata, and Citrus grandis Against Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Sholeh Saeb

    2016-11-01

    Full Text Available Background: Microorganisms resistant to most antibiotics are rapidly spreading, and there is an urgent and continuous need for novel antimicrobial compounds. The genus Citrus belongs to the family Rutaceae has many biologically active secondary metabolites. Objectives: The purpose of this study was to evaluate antimicrobial activity of essential oil and extract of Lemon (Citrus limon, Mandarin (Citrus reticulata and Pummelo (Citrus grandis against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Salmonella typhi. Materials and Methods: The fresh Citrus leaves were shade-dried and powdered. Antimicrobial metabolites were extracted from them by 80% methanol for extract and using a Clevenger-type apparatus for essential oil. Eight different concentrations of the each leaf extract and essential oil were prepared. The antimicrobial susceptibility assay of Citrus leaves metabolites were subjected against four bacterial strains by agar disc diffusion and E-test method. Results: In this study, minimum inhibitory concentrations (MIC of different Citrus leaf extracts were determined against all four food-borne pathogens. The C. grandis leaf essential oil had potent antimicrobial activity against all four pathogens, and the C. limon leaf essential oil was effective on Gram-positive bacteria. S. typhi was resistant against two leaves essential oils. Conclusions: The results showed that there was no antimicrobial activity effect in all extracts on tested bacteria. In this study, the antibacterial effect of essential oil of Citrus leaves on four strains of pathogenic microorganisms was confirmed. The C. grandis leaf essential oil had the most powerful antimicrobial properties, suggesting its potential application as natural preservative in foods or an effective medicine against different pathogenic microbes. Key words: Antibacterial activity, E-test, Citr

  10. Control of virus diseases of citrus.

    Science.gov (United States)

    Lee, Richard F

    2015-01-01

    Citrus is thought to have originated in Southeast Asia and horticulturally desirable clonal selections have been clonally cultivated for hundreds of years. While some citrus species have nucellar embryony, most cultivation of citrus has been by clonal propagation to ensure that propagated plants have the same traits as the parent selection. Clonal propagation also avoids juvenility, and the propagated plants produce fruit sooner. Because of the clonal propagation of citrus, citrus has accumulated a large number of viruses; many of these viruses are asymptomatic until a susceptible rootstock and/or scion is encountered. The viruses reported to occur in citrus will be summarized in this review. Methods of therapy to clean selected clones from viruses will be reviewed; the use of quarantine, clean stock, and certification programs for control of citrus viruses and other strategies to control insect spread citrus viruses, such as mild strain cross-protection and the use of pest management areas will be discussed.

  11. Relationship between the specific surface area of rust and the electrochemical behavior of rusted steel in a wet-dry acid corrosion environment

    Science.gov (United States)

    Liu, Wei; Zhao, Qing-he; Li, Shuan-zhu

    2017-01-01

    The relationship between the specific surface area (SSA) of rust and the electrochemical behavior of rusted steel under wet-dry acid corrosion conditions was investigated. The results showed that the corrosion current density first increased and then decreased with increasing SSA of the rust during the corrosion process. The structure of the rust changed from single-layer to double-layer, and the γ-FeOOH content decreased in the inner layer of the rust with increasing corrosion time; by contrast, the γ-FeOOH content in the outer layer was constant. When the SSA of the rust was lower than the critical SSA corresponding to the relative humidity during the drying period, condensed water in the micropores of the rust could evaporate, which prompted the diffusion of O2 into the rust and the following formation process of γ-FeOOH, leading to an increase of corrosion current density with increasing corrosion time. However, when the SSA of the rust reached or exceeded the critical SSA, condensate water in the micro-pores of the inner layer of the rust could not evaporate which inhibited the diffusion of O2 and decreased the γ-FeOOH content in the inner rust, leading to a decrease of corrosion current density with increasing corrosion time.

  12. Survey for Citrus diseases in French Guiana

    OpenAIRE

    Thermoz, Jean-Pierre

    2007-01-01

    The presence on the continent of major threats for Citrus orchards has required a survey to assess the situation of Citrus pathogens in the French territory of Guiana. Agriculture in French Guiana is located on the coast (about 300 Kms from west to east and 50 Km wide). There are 1200 Ha of Citrus orchards (Ministry of Agriculture). Citrus are grown either for export (Tahiti lime) or for local consumption : sweet oranges, tangerines and hybrids. Trees are grafted on Carrizo citrange, Rough le...

  13. Citrus Limonoids: Analysis, Bioactivity, and Biomedical Prospects

    Science.gov (United States)

    This publication is a review of the chemistry, biochemistry and bioactivity of limonoids occurring in citrus. The review chronologically relates the evolution of research in citrus limonoids beginning with their association with bitterness development in citrus juices. The chemical and biochemical...

  14. Soil Micronutrients and Citrus Growth

    Institute of Scientific and Technical Information of China (English)

    OUYANGTAO

    1993-01-01

    By using nutritional diagnosis of citrus leaves and determining soil micronutrients,the relationship between soil micronutrients and citrus growth in southern China has been studied.Studies showed that there was a significant positive correlation between available micronutrients (such as Zn,Mo,Cu)in the soil and the corresponding nutrients in citrus leaves.Thus,one can roughly learn of the sufficiency or deficiency of certain nutrients in soils by analyzing citrus leaves.Rational spray of Zn B or Mo fertilizer not only improved citrus yields but also increased the total sugar of Satsuma mandarin and of Xinhui orange by 2.9 and 17.2% respectively compared with the control.Spraying Mo fertilizer increased the vitamin C content of Satsuma mandarin juice by 4.7%-8.4%,maturated fruits 7-10 days earlier and gave the peel a brighter color.The ultramicroscopic characteristics of Zn-deficient citrus leaves were investigated under an electron microscope.Results showed that the Zn-deficient leaf cell was characterized mainly by poor cytoplasm,endoplasmic reticula and ribosomes and by big starch grains in the chloroplast.As a result of spraying Zn fertilizer the structure of the cell returned to normal,the cytoplasm became rich and the amount of chloroplast increased.There also appeared a great deal of multiform endoplasmic reticula,thus promoting the photosynthesis of Zn-deficient plants.This provides a cytologico-theoretical basis for fertilization of high-yielding citrus trees.

  15. Wheat Rust Information Resources - Integrated tools and data for improved decision making

    DEFF Research Database (Denmark)

    Hodson, David; Hansen, Jens Grønbech; Lassen, Poul

    Wheat rusts present an ever-changing global threat to the worlds wheat crop. Emergence of virulent new races in one region has implications for other regions, due to wind-borne or human-borne movements. Therefore informed decision making regarding control and mitigation of wheat rusts requires...... an integrated set of datasets on both pathogen and host at the global scale. The Global Cereal Rust Monitoring System (GCRMS), created under the Durable Rust resistance in Wheat (DRRW) project, represents a unique and increasingly comprehensive resource of rust information. A suite of tools are now available....... Integration of the CIMMYT Wheat Atlas and the Genetic Resources Information System (GRIS) databases provides a rich resource on wheat cultivars and their resistance to important rust races. Data access is facilitated via dedicated web portals such as Rust Tracker (www.rusttracker.org) and the Global Rust...

  16. Phytoseiidae (Acari: Mesostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Denmark, Harold A

    2011-08-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the family Phytoseiidae (Acari: Mesostigmata) in central and south central Florida. Inner and outer canopy leaves, open flowers, fruit, twigs, and trunk scrapings were sampled monthly between September 1994 and January 1996. Vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards. The two remaining orchards were on full herbicide programs and ground cover plants were absent. Thirty-three species of phytoseiid mites were identified from 35,405 specimens collected within citrus tree canopies within the seven citrus orchards, and 8,779 specimens from vines and ground cover plants within five of the seven orchards. The six most abundant phytoseiid species found within citrus tree canopies were: Euseius mesembrinus (Dean) (20,948), Typhlodromalus peregrinus (Muma) (8,628), Iphiseiodes quadripilis (Banks) (2,632), Typhlodromips dentilis (De Leon) (592), Typhlodromina subtropica Muma and Denmark (519), and Galendromus helveolus (Chant) (315). The six most abundant species found on vines or ground cover plants were: T. peregrinus (6,608), E. mesembrinus (788), T. dentilis (451), I. quadripilis (203), T. subtropica (90), and Proprioseiopsis asetus (Chant) (48). The remaining phytoseiids included: Amblyseius aerialis (Muma), A. herbicolus (Chant), A. largoensis (Chant), A. multidentatus (Chant), A. sp. near multidentatus, A. obtusus (Koch), Chelaseius vicinus (Muma), Euseius hibisci Chant, Galendromus gratus (Chant), Metaseiulus mcgregori (Chant), Neoseiulus mumai (Denmark), N. vagus (Denmark), Phytoscutus sexpilis (Muma), Phytoseiulus macropilis (Banks), Proprioseiopsis detritus (Muma), P. dorsatus (Muma), P. macrosetae (Banks), P. rotundus (Muma), P. solens (De Leon), Typhlodromips deleoni (Muma), T. dillus (De Leon), T. dimidiatus (De Leon), T. mastus Denmark and Muma, T. simplicissimus (De Leon), and T. sp

  17. A novel virus of the genus Cilevirus causing symptoms similar to citrus leprosis.

    Science.gov (United States)

    Roy, Avijit; Choudhary, Nandlal; Guillermo, Leon M; Shao, Jonathan; Govindarajulu, Ananthakrishnan; Achor, Diann; Wei, G; Picton, D D; Levy, L; Nakhla, M K; Hartung, John S; Brlansky, R H

    2013-05-01

    Citrus leprosis in Colombia was previously shown to be caused by cytoplasmic Citrus leprosis virus (CiLV-C). In 2011, enzyme-linked immunosorbent assay and reverse-transcription polymerase chain reaction (RT-PCR)-based diagnostic methods failed to identify CiLV-C from citrus samples with symptoms similar to citrus leprosis; however, virions similar to CiLV-C were observed in the cytoplasm of the symptomatic leaves by transmission electron microscopy. Furthermore, the causal organism was transmitted by the false spider mite, Brevipalpus phoenicis, to healthy citrus seedlings. A library of small RNAs was constructed from symptomatic leaves and used as the template for Illumina high-throughput parallel sequencing. The complete genome sequence and structure of a new bipartite RNA virus was determined. RNA1 (8,717 nucleotides [nt]) contained two open reading frames (ORFs). ORF1 encoded the replication module, consisting of five domains: namely, methyltransferase (MTR), cysteine protease-like, FtsJ-MTR, helicase (Hel), and RNA-dependent RNA polymerase (RdRp); whereas ORF2 encoded the putative coat protein. RNA2 (4,989 nt) contained five ORFs that encode the movement protein (MP) and four hypothetical proteins (p7, p15, p24, and p61). The structure of this virus genome resembled that of CiLV-C except that it contained a long 3' untranslated terminal region and an extra ORF (p7) in RNA2. Both the RNA1 and RNA2 of the new virus had only 58 and 50% nucleotide identities, respectively, with known CiLV-C sequences and, thus, it appears to be a novel virus infecting citrus. Phylogenetic analyses of the MTR, Hel, RdRp, and MP domains also indicated that the new virus was closely related to CiLV-C. We suggest that the virus be called Citrus leprosis virus cytoplasmic type 2 (CiLV-C2) and it should be unambiguously classified as a definitive member of the genus Cilevirus. A pair of CiLV-C2 genome-specific RT-PCR primers was designed and validated to detect its presence in citrus

  18. Domatia reduce larval cannibalism in predatory mites

    NARCIS (Netherlands)

    Ferreira, J.A.M.; Eshuis, B.; Janssen, A.; Sabelis, M.W.

    2008-01-01

    1. Acarodomatia are small structures on the underside of leaves of many plant species, which are mainly inhabited by carnivorous and fungivorous mites. 2. Domatia are thought to protect these mites against adverse environmental conditions and against predation. They are considered as an indirect pla

  19. Behavioural responses to potential dispersal cues in two economically important species of cereal-feeding eriophyid mites.

    Science.gov (United States)

    Kiedrowicz, Agnieszka; Kuczyński, Lechosław; Lewandowski, Mariusz; Proctor, Heather; Skoracka, Anna

    2017-06-20

    Passively dispersing organisms should optimise the time and direction of dispersal by employing behaviours that increase their probability of being successfully transported by dispersal agents. We rigorously tested whether two agriculturally important passively-dispersing eriophyoid species, wheat curl mite (WCM) and cereal rust mite (CRM), display behaviours indicating their readiness to depart from current host plants in the presence of potential dispersal cues: wind, an insect vector and presence of a fresh plant. Contrary to our expectations, we found that both species decreased their general activity in the presence of wind. When exposed to wind, WCM (but not CRM) significantly increased behaviour that has previously been considered to facilitate dispersal (in this case, standing vertically). Our study provides the first sound test of the function of what have been interpreted as dispersal-related behaviours of eriophyid mites. The low proportion of WCM exhibiting dispersal behaviour suggests there may be predisposed dispersers and residents in the population. Moreover, we found that WCM was generally more active than CRM, which is likely a contributing factor to its high invasive potential.

  20. Potential impacts of ambient ozone on wheat rust diseases and the role of plant ozone sensitivity

    Science.gov (United States)

    The resurgence of rust diseases and the continued rise in tropospheric ozone (O3) levels have the potential to limit global wheat production. We conducted a series of experiments to understand the potential interactions between these two stress factors. Both stem rust and leaf rust were increased o...

  1. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi

    Science.gov (United States)

    Rust fungi are obligate biotrophic pathogens causing considerable damage on crop plants. P. graminis f. sp. tritici, the causal agent of wheat stem rust, and M. larici-populina, the poplar rust pathogen, have strong deleterious impact on wheat and poplar wood production, respectively. The recently r...

  2. Genetic similarity among Agistemus pallinii Matioli et al (Acari: Stigmaeidae) found in citrus orchards in Vicosa, Minas Gerais state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Matioli, Andre L. [Instituto Biologico, Campinas, SP (Brazil). Lab. de Entomologia Economica], e-mail: almatioli@biologico.sp.gov.br; Pallini, Angelo [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Animal], e-mail: pallini@ufv.br; Tavares, Mara G. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Geral], e-mail: mtavares@ufv.br

    2009-03-15

    Stigmaeidae are very important predators of mite and insect pests on several crops in Brazil. It is considered the second most important family of predatory mites in citrus orchards in Brazil. However, their identification, especially that of the members of the genus Agistemus, is rather difficult based only on morphology. Hence, this study describes the use of random amplified polymorphic DNA (RAPD-PCR) markers to determine the genetic similarity of an Agistemus pallinii Matioli et al population found in 2004 in a citrus orchard in Vicosa, Minas Gerais State, Brazil, preying on Panonychus citri (McGregor). Amplifications were performed with 12 random primers (OPAA8, OPAA19, OPAB1, OPAB5, OPAB18, OPAC9, OPAC17, OPAC19, OPAD10, OPAE9, OPAE12 and OPAE17), which generated 119 bands, with 53.8% polymorphism. The coefficients of genetic similarity among the individuals ranged from 0.68 to 0.99, indicating a high genetic similarity among them. The 3D projection analysis clustered the majority of individuals confirming their high similarity. Though individuals of A. pallinii are minute ({+-} 360 {mu}m long), the PCR-RAPD technique can still be used for their identification, complementing morphological analyses or for comparison of populations collected in different geographic regions. This is the fi rst molecular study carried out with stigmaeid mites. (author)

  3. Prospects for advancing defense to cereal rusts through genetical genomics.

    Science.gov (United States)

    Ballini, Elsa; Lauter, Nick; Wise, Roger

    2013-01-01

    Rusts are one of the most severe threats to cereal crops because new pathogen races emerge regularly, resulting in infestations that lead to large yield losses. In 1999, a new race of stem rust, Puccinia graminis f. sp. tritici (Pgt TTKSK or Ug99), was discovered in Uganda. Most of the wheat and barley cultivars grown currently worldwide are susceptible to this new race. Pgt TTKSK has already spread northward into Iran and will likely spread eastward throughout the Indian subcontinent in the near future. This scenario is not unique to stem rust; new races of leaf rust (Puccinia triticina) and stripe rust (Puccinia striiformis) have also emerged recently. One strategy for countering the persistent adaptability of these pathogens is to stack complete- and partial-resistance genes, which requires significant breeding efforts in order to reduce deleterious effects of linkage drag. These varied resistance combinations are typically more difficult for the pathogen to defeat, since they would be predicted to apply lower selection pressure. Genetical genomics or expression Quantitative Trait Locus (eQTL) analysis enables the identification of regulatory loci that control the expression of many to hundreds of genes. Integrated deployment of these technologies coupled with efficient phenotyping offers significant potential to elucidate the regulatory nodes in genetic networks that orchestrate host defense responses. The focus of this review will be to present advances in genetical genomic experimental designs and analysis, particularly as they apply to the prospects for discovering partial disease resistance alleles in cereals.

  4. Application of Two-spotted Spider Mite Tetranychus urticae for Plant-pest Interaction Studies

    Science.gov (United States)

    Negrave, Tara; Van Leeuwen, Thomas; Grbic, Vojislava; Grbic, Miodrag

    2014-01-01

    The two-spotted spider mite, Tetranychus urticae, is a ubiquitous polyphagous arthropod herbivore that feeds on a remarkably broad array of species, with more than 150 of economic value. It is a major pest of greenhouse crops, especially in Solanaceae and Cucurbitaceae (e.g., tomatoes, eggplants, peppers, cucumbers, zucchini) and greenhouse ornamentals (e.g., roses, chrysanthemum, carnations), annual field crops (such as maize, cotton, soybean, and sugar beet), and in perennial cultures (alfalfa, strawberries, grapes, citruses, and plums)1,2. In addition to the extreme polyphagy that makes it an important agricultural pest, T. urticae has a tendency to develop resistance to a wide array of insecticides and acaricides that are used for its control3-7. T. urticae is an excellent experimental organism, as it has a rapid life cycle (7 days at 27 °C) and can be easily maintained at high density in the laboratory. Methods to assay gene expression (including in situ hybridization and antibody staining) and to inactivate expression of spider mite endogenous genes using RNA interference have been developed8-10. Recently, the whole genome sequence of T. urticae has been reported, creating an opportunity to develop this pest herbivore as a model organism with equivalent genomic resources that already exist in some of its host plants (Arabidopsis thaliana and the tomato Solanum lycopersicum)11. Together, these model organisms could provide insights into molecular bases of plant-pest interactions. Here, an efficient method for quick and easy collection of a large number of adult female mites, their application on an experimental plant host, and the assessment of the plant damage due to spider mite feeding are described. The presented protocol enables fast and efficient collection of hundreds of individuals at any developmental stage (eggs, larvae, nymphs, adult males, and females) that can be used for subsequent experimental application. PMID:25046103

  5. The role of mites in insect-fungus associations

    Science.gov (United States)

    R. W. Hofstetter; J. C. Moser

    2014-01-01

    The interactions among insects, mites, and fungi are diverse and complex but poorly understood in most cases. Associations among insects, mites, and fungi span an almost incomprehensible array of ecological interactions and evolutionary histories. Insects and mites often share habitats and resources and thus interact within communities. Many mites and insects rely on...

  6. Effectivity of Kaffir lime (Citrus hystrix, Nasnaran Mandarin (Citrus amblycarpa, and Pomelo (Citrus maxima Leaf Extract Against Aedes aegypti Larvae

    Directory of Open Access Journals (Sweden)

    Hebert Adrianto

    2014-03-01

    Full Text Available The used of chemicals as larvicidal may causing resistance, health problem, and environment problem. Leaf extracts of Citrus as biolarvicidal against Aedes aegypti larvae can be used as an alternative larvicidal. The aims of this study is to find out the species of Citrus in the study sample, which is the most effective as biolarvicidal. This study was conducted using nested experiment design, with six treatments and five replicates. Larvae mortality was observed after 24 and 48 hours. Then, data were analyzed by probit. The results of this study show that (1 the LC95 value after 24 hours of exposure of leaf extracts of Citrus hystrix, Citrus amblycarpa, and Citrus maxima, were each 3,176 ppm; 4,174 ppm; and 6,369 ppm. (2 the LC95 value after 48 hours of exposure of leaf extracts of Citrus hystrix, Citrus amblycarpa, and Citrus maxima, were each 2,499 ppm; 3,256 ppm; and 4,886 ppm. (3 leaf extract of Citrus hystrix is the most effective among others as biolarvicidal against Aedes aegypti larvae. Leaf extract of Citrus hystrix can be used as alternative biolarvicidal.

  7. Haematophagus Mites in Poultry Farms of Iran

    Science.gov (United States)

    Rahbari, S; Nabian, S; Ronaghi, H

    2009-01-01

    Background: Blood sucking mites are important avian ectoparasites which being found on bird species worldwide. Their presence are problematic for the producers either through potential direct effects on weight gain, egg production, sperm production in roosters or as nuisance pests on worker handle hens and eggs. The aim of this study was pointing out of the status of haematophagus mites. Methods: Eight caged layer and four breeder flocks were visited, monitoring for the presence of chicken mites performed by removing and examining debris from poultry house, infested nesting material collected into zip lock plastic bags and at least 20 birds were also randomly selected to examine the presence of chicken mites. Mites obtained from each population were mounted in Hoyer’s medium on microscope slides and identified. All eight caged layer and four breeder flocks were inspected, which were infested with chicken blood feeding mites. Results: Massive infestations of Dermanyssus gallinae were common with huge numbers of parasites on birds, cages and the conveyor belts for egg. Only one farm from Mazandaran Province was infested to Ornithonyssus bursa. Conclusion: Dermanyssus gallinae was the most prevalent blood feeder mite in the breeder and caged layer flocks in Iran, while O. bursa was reported as a first record, which found only in a breeder flock in Mazanderan Province. It seems that its presence is limited into the area which affected by both warm and humid environmental conditions. PMID:22808378

  8. Haematophagus Mites in Poultry Farms of Iran

    Directory of Open Access Journals (Sweden)

    S Rahbari

    2009-12-01

    Full Text Available Background: Blood sucking mites are important avian ectoparasites which being found on bird species worldwide. Their presence are problematic for the producers either through potential direct effects on weight gain, egg produc­tion, sperm production in roosters or as nuisance pests on worker handle hens and eggs. The aim of this study was pointing out of the status of haematophagus mites.Methods: Eight caged layer and four breeder flocks were visited, monitoring for the presence of chicken mites per­formed by removing and examining debris from poultry house, infested nesting material collected into zip lock plas­tic bags and at least 20 birds were also randomly selected to examine the presence of chicken mites. Mites obtained from each population were mounted in Hoyer,s medium on microscope slides and identified. All eight caged layer and four breeder flocks were inspected, which were infested with chicken blood feeding mites.Results: Massive infestations of Dermanyssus gallinae were common with huge numbers of parasites on birds, cages and the conveyor belts for egg. Only one farm from Mazandaran Province was infested to Ornithonyssus bursa.Conclusion: Dermanyssus gallinae was the most prevalent blood feeder mite in the breeder and caged layer flocks in Iran, while O. bursa was reported as a first record, which found only in a breeder flock in Mazanderan Province. It seems that its presence is limited into the area which affected by both warm and humid environmental conditions.

  9. Comparison of thread-cutting behaviour in three specialist predatory mites to cope with complex webs of Tetranychus spider mites

    NARCIS (Netherlands)

    Shimoda, T.; Kishimoto, H.; Takabayashi, J.; Amano, H.; Dicke, M.

    2009-01-01

    Anti-predator defenses provided by complex webs of Tetranychus mites can severely impede the performance of generalist predatory mites, whereas this may not be true for specialist predatory mites. Although some specialist predatory mites have developed morphological protection to reduce the adverse

  10. Selection of Arabic coffee progenies with rust resistance

    Directory of Open Access Journals (Sweden)

    Gustavo Hiroshi Sera

    2014-07-01

    Full Text Available The aim of this study was to select high-yielding coffee progenies with resistance to coffee leaf rust for the State of Paraná (Brazil. Field experiments in a randomized block design were carried out in Itaguajé and Congonhinhas. Yield, vegetative vigor and rust resistance of nine progenies of Arabic coffee and three check cultivars were evaluated. Many genotypes derived from “Sarchimor” and “Catucaí” were susceptible. Three coffee genotypes of Sarchimor germplasm and the F6 generation of genotype “Catuaí x (Catuaí x BA-10 coffee” were selected to advance generations and are promising to become new cultivars for being higher-yielding than ‘IAPAR 59’ and ‘Tupi IAC 1669-33’ and having a large number of plants with complete rust resistance.

  11. Resposta diferencial de espécies e de híbridos de citros à leprose Differential response of citrus species and hybrids to leprosis

    Directory of Open Access Journals (Sweden)

    Juliana Freitas-Astúa

    2008-07-01

    Full Text Available O objetivo deste trabalho foi buscar novas fontes de resistência à leprose-dos-citros, no Banco Ativo de Germoplasma do Centro APTA Citros Sylvio Moreira, Instituto Agronômico, em Cordeirópolis, SP. Foram utilizadas plantas obtidas por sementes de 26 acessos, infectadas com o vírus da leprose-dos-citros (Citrus leprosis virus - CiLV, por meio do seu vetor Brevipalpus phoenicis. O aparecimento de lesões, a partir de 21 dias após a inoculação, foi observado em 11 dos genótipos testados (42,3%. Quinze espécies, entre elas Citrus pennivesiculata e C. celebica, comportaram-se como altamente resistentes, enquanto outras, como C. keraji, foram mais suscetíveis que o padrão C. sinensis. Os dados mostraram grande variação de respostas de Citrus spp. à leprose, com elevado número de espécies resisentes, que podem ser utilizadas como fonte de resistência à doença em programas de melhoramento.The objective of this work was to prospect for new sources of resistance to leprosis in the Citrus Germplasm Bank of Centro APTA Citros Sylvio Moreira, Instituto Agronômico, in Cordeirópolis, SP, Brazil. Plants obtained through seeds from 26 citrus accessions were mite-infected with Citrus leprosis virus (CiLV. Typical lesions started to appear in 11 genotypes (42.3% of the tested accessions 21 days after inoculation. Fifteen species, among them Citrus pennivesiculata and C. celebica, behaved as highly resistant, while other genotypes, as C. keraji, were more susceptible than the standard C. sinensis. The data showed a wide variation in the response of Citrus spp. to leprosis, with a large number of resistant species, wich can be used as source of resistance to this disease, in breeding programs.

  12. Allergy to house dust mites and asthma.

    Science.gov (United States)

    Milián, Evelyn; Díaz, Ana María

    2004-03-01

    House dust mites have been shown to be important sources of indoor allergens associated with asthma and other allergic conditions. Asthma is a chronic respiratory disease that affects millions of people worldwide, and numerous scientific studies have shown that the prevalence of asthma is increasing. The most common dust mite species around the world include Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), Euroglyphus maynei (Em) and Blomia tropicalis (Bt). Over the past three decades, many important allergens from these species have been identified and characterized at the molecular level. The biological function of several house dust mite allergens has been elucidated, with many of them showing enzymatic activity. However, Bt allergens remain the least studied, even though this mite is very common in tropical and subtropical regions of the world, including Puerto Rico. Therefore, it is very important to include Bt in diagnostic and therapeutic strategies for house dust mite induced allergy and asthma, particularly in areas where Bt exposure and sensitization is high. Recombinant DNA technology, as well as other molecular biology and immunological techniques, have played a fundamental role in advances towards a better understanding of the biology of house dust mites and their role in allergic diseases. This kind of study also contributes to the understanding of the complex immunologic mechanisms involved in allergic reactions. The development of effective diagnostic and therapeutic approaches depends on the continuity of research of house dust mite allergens. The objectives of this review are to describe the most important aspects of house dust mite allergy and to acquaint the scientific community with the latest findings pertaining to house dust mite allergens, particularly those derived from Bt.

  13. 虫源性柑橘果面伤痕诊断%Diagnosis of Insect-originated Citrus Fruit Scarring

    Institute of Scientific and Technical Information of China (English)

    于法辉; 张宏宇

    2012-01-01

    我国超过巴西成为世界上柑橘生产第一大国,而我国柑橘出口量排在全球第六名,仅为全球出口总量的6.5%,影响出口因素之一是果实外观品质低下.由于生物、机械和化学等因素在果实生长期对果实外表造成伤害,使成熟果实留下疤痕.造成柑橘果面伤痕的虫害主要有蓟马、螽蟖、螨类、蚧类、卷叶蛾、潜叶蛾、叶甲类、叶蝉、蜗牛等,根据近几年的研究调查并结合国内外相关文献,综述了主要虫源性柑橘果面伤痕症状,为快速准确诊断害虫种类,制定有效的防治措施提供依据.%China is the first superpower of citrus production in the world, but the export value of citrus ranks the 6th in the world, only account for 6.5% of total global exports. Many factors are affecting exportion; And low appearance quality caused by diseases and pests is one of the main factors. Due to biological (e.g. Insect, disease or mite), mechanical (e.g. Hail, wind rubbing or agricultural operations) and chemical (e.g., pesticides) factors, citrus fruits show surface defects with scarring appearance during fruit growth period. The insect pests causing this type of damage include various kinds of insect pests such as citrus thrip, katydid, mite, scale insects, fruit tree leafroller, citrus leafminer, leaf beetle, leafhopper, snail and so on. Their characteristic damage symptoms was reviewed respectively for rapid and accurate diagnosis of those insect-originated citrus fruit scarring, in order to improve citrus quality.

  14. Amino acid assisted dehalogenation of carbon tetrachloride by green rust

    DEFF Research Database (Denmark)

    Yin, Weizhao; Strobel, Bjarne W.; Hansen, Hans Chr. Bruun

    2017-01-01

    Layered FeII-FeIII hydroxides (green rusts, GR) are promising reactants for reductive dechlorination of chlorinated solvents due to high reaction rates and the opportunity to inject reactive slurries of the compounds into contaminant plumes. However, it is necessary to develop strategies that red......Layered FeII-FeIII hydroxides (green rusts, GR) are promising reactants for reductive dechlorination of chlorinated solvents due to high reaction rates and the opportunity to inject reactive slurries of the compounds into contaminant plumes. However, it is necessary to develop strategies...

  15. 'Wuzishatangju' mandarin (Citrus reticulata Blanco)

    African Journals Online (AJOL)

    ARL4

    African Journal of Biotechnology Vol. 11(89), pp. ... increased to meet the challenge of process industry and particular consumer ... biotechnology, the advent of molecular markers has made it ..... Innovation and Utilization for Germplasm Resources in ... Construction of DNA fingerprinting database of citrus cultivars. (Lines).

  16. Light and scanning electron microscopic investigations on MiteStop-treated poultry red mites.

    Science.gov (United States)

    Locher, Nina; Klimpel, Sven; Abdel-Ghaffar, Fathy; Al Rasheid, Khaled A S; Mehlhorn, Heinz

    2010-07-01

    Recent studies of the neem seed product MiteStop showed that it has a good acaricidal effect against all developmental stages of the poultry red mite, Dermanyssus gallinae. In vitro tests proved an efficacy at direct contact, as well as by fumigant toxicity. Light and scanning electron microscopic (SEM) investigations showed no clear, morphologically visible signs of an effect caused by fumigant toxicity. Direct contact with the neem product, however, seemed to be of great impact. Chicken mites turned dark brown or even black after being treated with the neem product. SEM analysis showed damages along the body surface of the mites.

  17. Phylogenetic and Molecular Variability Studies Reveal a New Genetic Clade of Citrus leprosis virus C.

    Science.gov (United States)

    Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Breton, Michèle Claire; Arena, Gabriella Dias; Nunes, Maria Andreia; Kitajima, Elliot Watanabe; Machado, Marcos Antonio; Freitas-Astúa, Juliana

    2016-06-06

    Citrus leprosis virus C (CiLV-C) causes a severe disease affecting citrus orchards in the Western hemisphere. This study reveals the molecular variability of the virus by analyzing four genomic regions (p29, p15, MP and RNA2-intergenic region) distributed over its two RNAs. Nucleotide diversity (π) values were relatively low but statistically different over the analyzed genes and subpopulations, indicating their distinct evolutionary history. Values of πp29 and πMP were higher than those of πp15 and πRNA2-IR, whereas πMP was increased due to novel discovered isolates phylogenetically clustered in a divergent clade that we called SJP. Isolate BR_SP_SJP_01 RNA1 and RNA2 sequences, clade SJP, showed an identity of 85.6% and 88.4%, respectively, with those corresponding to CiLV-C, the type member of the genus Cilevirus, and its RNA2 5'-proximal region was revealed as a minor donor in a putative inter-clade recombination event. In addition to citrus, BR_SP_SJP_01 naturally infects the weed Commelina benghalensis and is efficiently transmitted by Brevipalpus yothersi mites. Our data demonstrated that negative selection was the major force operating in the evaluated viral coding regions and defined amino acids putatively relevant for the biological function of cilevirus proteins. This work provides molecular tools and sets up a framework for further epidemiological studies.

  18. Symptoms of pests, rust and other disorders on leaves of willow fertilised with wastewater, urine or sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Aahman, Inger [Faculty of Landscape Planning, Horticulture and Agricultural Science, Swedish University of Agricultural Sciences, P.O. Box 44, SE-23053 Alnarp (Sweden); Wilson, Fiona [DOE Environment and Heritage Service, Water Management Unit, Agricultural Regulations Team, 17 Antrim Road, Lisburn BT28 3AL (United Kingdom)

    2008-11-15

    Willow (Salix viminalis) irrigated with three different dosages of wastewater has been investigated for leaf damages in four plantations located in Sweden, Northern Ireland, France and Greece, during 3 consecutive years. Control treatments were clean water and/or no water. Additionally, the plantation in Sweden included a human urine/water mix treatment and the one in N. Ireland a sewage sludge treatment. Few effects of the treatments were found. In the Greek trial, all treatments were affected by abiotic stress causing leaf discolouration, necrosis and leaf curling, but the control treatment was least affected. Mite infestations were also less prevalent in the control plots there. In the French trial, control leaves were less galled by Dasineura marginemtorquens than leaves from the lowest dose of wastewater but not compared to the two higher doses of wastewater, during 1 of the 3 years. At the same site, but in another year, Melampsora rust infection was least developed at the highest dose of wastewater but only significantly so when compared to the intermediate dose of wastewater. Urine/water treatment resulted in more rust and leaf margin damages than the control treatments in 1 year. Also, leaf spotting by leafhoppers tended to be more prevalent on the urine treatment. However, since the urine fertilisation favours willow growth as well, a somewhat enhanced biotic damage to leaves is probably no reason for avoiding this application in full-scale plantations. Damage by chrysomelid beetles was very common in the French and the N. Irish plantations, but no significant differences between treatments were found. Neither were there any treatment effects on symptoms by aphids. (author)

  19. Field ID guide to citrus relative hosts of Asian citrus psyllid & Huanglongbing

    Science.gov (United States)

    The Rutaceae family of plants includes not only species within the genus Citrus, but also several other genera and species that may not be easily recognized as having any relationship to citrus at all. However, many of these citrus relatives are used for ornamental, culinary, or religious purposes. ...

  20. 78 FR 63369 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

    Science.gov (United States)

    2013-10-24

    ... infected plants, which render the fruit unmarketable, and cause infected fruit to drop from the trees... of the fruit, and can kill trees. Once infected, there is no cure for a tree with citrus greening. In... disease that is caused by a complex of Xanthomonas spp. bacteria and that affects plants and plant...

  1. Astigmatid mites (Acari: Sarcoptiformes) of forensic interest.

    Science.gov (United States)

    Oconnor, Barry M

    2009-10-01

    This paper reviews the occurrence of mites of the infraorder Astigmata in situations involving the legal system, particularly in the area of medicocriminal entomology. Species in the families Acaridae, Lardoglyphidae and Histiostomatidae are encountered in stored food products and in vertebrate carrion, including human remains. Some of these species are incidentals, whereas others are obligate necrophages. Phoretic associations between these mites and insects allows for rapid dispersal and colonization of such patchy resources.

  2. The role of mites in insect-fungus associations.

    Science.gov (United States)

    Hofstetter, R W; Moser, J C

    2014-01-01

    The interactions among insects, mites, and fungi are diverse and complex but poorly understood in most cases. Associations among insects, mites, and fungi span an almost incomprehensible array of ecological interactions and evolutionary histories. Insects and mites often share habitats and resources and thus interact within communities. Many mites and insects rely on fungi for nutrients, and fungi benefit from them with regard to spore dispersal, habitat provision, or nutrient resources. Mites have important impacts on community dynamics, ecosystem processes, and biodiversity within many insect-fungus systems. Given that mites are understudied but highly abundant, they likely have bigger, more important, and more widespread impacts on communities than previously recognized. We describe mutualistic and antagonistic effects of mites on insect-fungus associations, explore the processes that underpin ecological and evolutionary patterns of these multipartite communities, review well-researched examples of the effects of mites on insect-fungus associations, and discuss approaches for studying mites within insect-fungus communities.

  3. The citrus leprosis pathosystem O patossistema leprose dos citros

    Directory of Open Access Journals (Sweden)

    Marinês Bastianel

    2006-09-01

    Full Text Available Citrus leprosis is considered the main viral disease for the Brazilian citrus production, particularly for the State of São Paulo, due to the high costs spent for the chemical control of its vector, the tenuipalpid mite Brevipalpus phoenicis. In addition, its global importance has significantly increased in the last years, with the dissemination of the virus to new countries in South and Central America. In Brazil, despite its economical importance and occurrence for more than seven decades, the most significant advances towards understanding the pathosystem interactions have been obtained only in the last ten years. This review focuses on various aspects of the disease, beginning with a historical view, its main characteristics, alternatives for its control, its increasing economical importance in Brazil and abroad, and the new data on the search for understanding the interactions amongst the mite vector, the virus, and the plant host.A leprose dos citros é considerada a principal virose na citricultura brasileira, com maior destaque no Estado de São Paulo, principalmente pelos altos custos demandados para o controle químico do vetor, o ácaro Brevipalpus phoenicis. Além da relevância dessa virose para a citricultura local, sua importância mundial vem sendo ampliada consideravelmente nos últimos anos, principalmente com a disseminação do vírus em novos países da América do Sul e Central. No Brasil, apesar da sua importância econômica e ocorrência por mais de sete décadas, os mais importantes avanços no entendimento das interações do patossistema leprose têm sido obtidos apenas nos últimos dez anos. Essa revisão aborda os diferentes aspectos dessa doença, trazendo um breve histórico da doença, principais características da leprose, alternativas de controle, sua crescente importância econômica na cadeia citrícola nacional, os mais recentes relatos de sua ocorrência em outros países e os novos resultados obtidos

  4. Asian citrus psyllid RNAi pathway : RNAi evidence

    OpenAIRE

    Taning, Clauvis N. T.; Andrade, Eduardo C.; Hunter, Wayne B.; Olivier Christiaens; Guy Smagghe

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if t...

  5. Genotypic variability and relationships between mite infestation levels, mite damage, grooming intensity, and removal of Varroa destructor mites in selected strains of worker honey bees (Apis mellifera L.).

    Science.gov (United States)

    Guzman-Novoa, Ernesto; Emsen, Berna; Unger, Peter; Espinosa-Montaño, Laura G; Petukhova, Tatiana

    2012-07-01

    The objective of this study was to demonstrate genotypic variability and analyze the relationships between the infestation levels of the parasitic mite Varroa destructor in honey bee (Apis mellifera) colonies, the rate of damage of fallen mites, and the intensity with which bees of different genotypes groom themselves to remove mites from their bodies. Sets of paired genotypes that are presumably susceptible and resistant to the varroa mite were compared at the colony level for number of mites falling on sticky papers and for proportion of damaged mites. They were also compared at the individual level for intensity of grooming and mite removal success. Bees from the "resistant" colonies had lower mite population rates (up to 15 fold) and higher percentages of damaged mites (up to 9 fold) than bees from the "susceptible" genotypes. At the individual level, bees from the "resistant" genotypes performed significantly more instances of intense grooming (up to 4 fold), and a significantly higher number of mites were dislodged from the bees' bodies by intense grooming than by light grooming (up to 7 fold) in all genotypes. The odds of mite removal were high and significant for all "resistant" genotypes when compared with the "susceptible" genotypes. The results of this study strongly suggest that grooming behavior and the intensity with which bees perform it, is an important component in the resistance of some honey bee genotypes to the growth of varroa mite populations. The implications of these results are discussed.

  6. Pathological and molecular characterizations of slow leaf rusting in ...

    African Journals Online (AJOL)

    ... 121R63-1 (77-5) and 29R45 (12-5), under controlled laboratory conditions. ... that is, <250.0 in the resistant genotypes, while it was beyond 1000.0 in 'Agra Local'. ... used as parental lines in the development of more durable rust resistance.

  7. White pines, Ribes, and blister rust: integration and action

    Science.gov (United States)

    R. S. Hunt; B. W. Geils; K. E. Hummer

    2010-01-01

    The preceding articles in this series review the history, biology and management of white pine blister rust in North America, Europe and eastern Asia. In this integration, we connect and discuss seven recurring themes important for understanding and managing epidemics of Cronartium ribicola in the white pines (five-needle pines in subgenus Strobus). Information and...

  8. Eliminating blister rust cankers from sugar pine by pruning.

    Science.gov (United States)

    G. L. Hayes; William I. Stein

    1957-01-01

    Well-stocked patches of vigorous advance reproduction are found in many deteriorating old-growth stands in southwestern Oregon. If carefully released from the over story, this reproduction can shorten the rotation length of the next crop by many years. Often sugar pine is the fastest-growing component of the reproduction, but it is frequently infected with blister rust...

  9. White pine blister rust resistance research in Minnesota and Wisconsin

    Science.gov (United States)

    Andrew David; Paul Berrang; Carrie Pike

    2012-01-01

    The exotic fungus Cronartium ribicola causes the disease white pine blister rust on five-needled pines throughout North America. Although the effects of this disease are perhaps better known on pines in the western portion of the continent, the disease has also impacted regeneration and growth of eastern white pine (Pinus strobus L. ...

  10. Blister rust control in the management of western white pine

    Science.gov (United States)

    Kenneth P. Davis; Virgil D. Moss

    1940-01-01

    The forest industry of the western white pine region depends on the production of white pine as a major species on about 2,670,000 acres of commercial forest land. Continued production of this species and maintenance of the forest industry at anything approaching its present level is impossible unless the white pine blister rust is controlled. Existing merchantable...

  11. White pines, Ribes, and blister rust: a review and synthesis

    Science.gov (United States)

    Brian W. Geils; Kim E. Hummer; Richard S. Hunt

    2010-01-01

    For over a century, white pine blister rust (Cronartium ribicola) has linked white pines (Strobus) with currants and gooseberries (Ribes) in a complex and serious disease epidemic in Asia, Europe, and North America. Because of ongoing changes in climate, societal demands for forests and their amenities, and scientific advances in genetics and proteomics, our current...

  12. White pine blister rust in the interior Mountain West

    Science.gov (United States)

    Kelly Burns; Jim Blodgett; Dave Conklin; Brian Geils; Jim Hoffman; Marcus Jackson; William Jacobi; Holly Kearns; Anna Schoettle

    2010-01-01

    White pine blister rust is an exotic, invasive disease of white, stone, and foxtail pines (also referred to as white pines or five-needle pines) in the genus Pinus and subgenus Strobus (Price and others 1998). Cronartium ribicola, the fungus that causes WPBR, requires an alternate host - currants and gooseberries in the genus Ribes and species of Pedicularis...

  13. Molecular Characterization of wheat stem rust races in Kenya

    Science.gov (United States)

    Stem or black rust caused by Puccinia graminis f. sp. tritici (Pgt) Erikss. & Henning causes severe losses to wheat (Triticum aestivum L.), historically threatening global wheat production. Characterizing prevalent isolates of Pgt would enhance the knowledge of population dynamics and evolution of t...

  14. Transformation of Chlorinated Hydrocarbons on Synthetic Green Rusts

    Science.gov (United States)

    Green rusts (GRs) are layered double hydroxides that contain both ferrous and ferric ions in their structure. GRs can potentially serve as a chemical reductant for degradation of chlorinated hydrocarbons. GRs are found in zerovalent iron based permeable reactive barriers and in c...

  15. Reductive and sorptive properties of sulfate green rust (GRSO4)

    DEFF Research Database (Denmark)

    Nedel, Sorin

    The Fe(II), Fe(III) hydroxide containing sulfate in its structure, called sulfate green rust (GRSO4), can effectively reduce and convert contaminants to less mobile and less toxic forms. However, the ability of GRSO4 to remove positively charged species from solution, via sorption, is very limited...

  16. Mapping Wheat Stem Rust Resistance Genes in 'Kingbird'

    Science.gov (United States)

    Stem rust caused by the fungus Puccinia graminis f. sp. tritici has historically been one of the most important diseases of wheat. Although losses have been much reduced in the last fifty years, new highly virulent races of the pathogen have recently emerged in East Africa. These new races are virul...

  17. Improvement of wheat in Zambia using incomplete resistance against rusts

    NARCIS (Netherlands)

    Milliano, de W.A.J.

    1983-01-01

    The programme of wheat improvement developed in Zambia used local facilities (finance, personnel, infrastructure), low budget, and few personnel. Incomplete resistance against rusts was used to obtain durable resistance.
    The abiotic conditions, socio-economic status of the farmers,

  18. Citrus allergy from pollen to clinical symptoms.

    Directory of Open Access Journals (Sweden)

    Rosa Anna Iorio

    Full Text Available Allergy to citrus fruits is often associated with pollinosis and sensitization to other plants due to a phenomenon of cross-reactivity. The aims of the present study were to highlight the cross-reactivity among citrus and the major allergenic pollens/fruits, throughout clinical and molecular investigations, and to evaluate the sensitization frequency to citrus fruits in a population of children and adults with pollinosis. We found a relevant percentage of sensitisation (39% to citrus fruits in the patients recruited and in all of them the IgE-mediated mechanism has been confirmed by the positive response to the prick-to-prick test. RT-PCR experiments showed the expression of Cit s 1, Cit s 3 and a profilin isoform, already described in apple, also in Citrus clementine pollen. Data of multiple sequence alignments demonstrated that Citrus allergens shared high percentage identity values with other clinically relevant species (i.e. Triticum aestivum, Malus domestica, confirming the possible cross-allergenicity citrus/grasses and citrus/apple. Finally, a novelty of the present work has been the expression of two phospholipaseA2 isoforms (PLA2 α and β in Citrus as well as in Triticum pollens; being PLA2 able to generate pro-inflammatory factors, this enzyme could participate in the activation of the allergenic inflammatory cascade.

  19. Mapping of stripe rust resistance gene in an Aegilops caudata introgression line in wheat and its genetic association with leaf rust resistance

    Indian Academy of Sciences (India)

    PUNEET INDER TOOR; SATINDER KAUR; MITALY BANSAL; BHARAT YADAV; PARVEEN CHHUNEJA

    2016-12-01

    A pair of stripe rust and leaf rust resistance genes was introgressed from Aegilops caudata, a nonprogenitor diploid species with the CC genome, to cultivated wheat. Inheritance and genetic mapping of stripe rust resistance gene in backcrossrecombinant inbred line (BC-RIL) population derived from the cross of a wheat–Ae. caudata introgression line (IL) T291-2(pau16060) with wheat cv. PBW343 is reported here. Segregation of BC-RILs for stripe rust resistance depicted a single major gene conditioning adult plant resistance (APR) with stripe rust reaction varying from TR-20MS in resistant RILs signifying the presence of some minor genes as well. Genetic association with leaf rust resistance revealed that two genes are located at a recombination distance of 13%. IL T291-2 had earlier been reported to carry introgressions on wheat chromosomes 2D, 3D, 4D, 5D, 6D and 7D. Genetic mapping indicated the introgression of stripe rust resistance gene on wheat chromosome 5DS in the region carrying leaf rust resistance gene LrAc, but as an independent introgression. Simple sequence repeat (SSR) and sequence-tagged site (STS) markers designed from the survey sequence data of 5DS enriched the target region harbouring stripe and leaf rust resistance genes. Stripe rust resistance locus, temporarily designated as YrAc, mapped at the distal most end of 5DS linked with a group of four colocated SSRs and two resistance gene analogue (RGA)-STS markers at a distanceof 5.3 cM. LrAc mapped at a distance of 9.0 cM from the YrAc and at 2.8 cM from RGA-STS marker Ta5DS_2737450, YrAc and LrAc appear to be the candidate genes for marker-assisted enrichment of the wheat gene pool for rust resistance.

  20. Scent of a mite: origin and chemical characterization of the lemon-like flavor of mite-ripened cheeses.

    Science.gov (United States)

    Brückner, Adrian; Heethoff, Michael

    2016-07-01

    Cheese infested with cheese mites is usually treated as unpalatable. Nevertheless, some traditional cheese manufactories in Germany and France intentionally use mites for fermentation of special varieties (i.e. Milbenkäse and Mimolette). While their production includes different mite species, both are characterized by a "lemon-like" flavor. However, the chemical nature and origin of this flavor-component is unknown. The cheese mites possess a pair of opisthosomal glands producing blends of hydrocarbons, terpenes and aromatics. Here, we describe the chemical profiles of the astigmatid mite species Tyrolichus casei (Milbenkäse) and Acarus siro (Mimolette). Although the chemical profiles differ in several aspects, both mite species produce neral (a volatile flavor component of lemon oil), which was absent from the headspace of both cheeses without mites. We conclude that the lemon-like flavor of mite cheese is not a consequence of fermentation of the cheese itself but a component from secretions of the cheese mites.

  1. Efficacy of five selected acaricides against Tetranychus urticae (Acari: Tetranychidae) and their side effects on relevant natural enemies occurring in citrus orchards.

    Science.gov (United States)

    Urbaneja, Alberto; Pascual-Ruiz, Sara; Pina, Tatiana; Abad-Moyano, Raquel; Vanaclocha, Pilar; Montón, Helga; Dembilio, Oscar; Castañera, Pedro; Jacas, Josep A

    2008-08-01

    Three groups of natural enemies are fundamental in citrus IPM in Spain: coccinellid and phytoseiid predators and hymenopteran parasitoids. Tetranychus urticae Koch is an important pest affecting citrus, for which biological control has not yet been achieved; therefore, acaricides are commonly used to control it. The goal of this study was to measure the efficacy of different acaricides on this mite and their side effects on three natural enemies relevant for citrus (Cryptolaemus montrouzieri Mulsant, Neoseiulus californicus McGregor and Aphidius colemani Viereck). Some products proved highly effective against T. urticae and harmless to A. colemani (mineral oil, tebufenpyrad, clofentezine and fenazaquin). However, almost all products tested were slightly harmful for both the predators considered. Fenazaquin was even moderately harmful for N. californicus. Further studies, like that presented here, are necessary to gain a better understanding of integrating biological and chemical controls. When considering both efficacy and side effects on beneficial arthropods, the best options would seem to be mineral oil, tebufenpyrad and clofentezine. However, it is urgent to complete testing of the side effects of the acaricides used in citrus. This question is crucial if the fact that two recently introduced Tetranychidae are being controlled in citrus by chemical means exclusively is considered.

  2. Mitochondrial genome evolution and tRNA truncation in Acariformes mites: new evidence from eriophyoid mites.

    Science.gov (United States)

    Xue, Xiao-Feng; Guo, Jing-Feng; Dong, Yan; Hong, Xiao-Yue; Shao, Renfu

    2016-01-06

    The subclass Acari (mites and ticks) comprises two super-orders: Acariformes and Parasitiformes. Most species of the Parasitiformes known retained the ancestral pattern of mitochondrial (mt) gene arrangement of arthropods, and their mt tRNAs have the typical cloverleaf structure. All of the species of the Acariformes known, however, have rearranged mt genomes and truncated mt tRNAs. We sequenced the mt genomes of two species of Eriophyoidea: Phyllocoptes taishanensis and Epitrimerus sabinae. The mt genomes of P. taishanensis and E. sabinae are 13,475 bp and 13,531 bp, respectively, are circular and contain the 37 genes typical of animals; most mt tRNAs are highly truncated in both mites. On the other hand, these two eriophyoid mites have the least rearranged mt genomes seen in the Acariformes. Comparison between eriophyoid mites and other Aacariformes mites showed that: 1) the most recent common ancestor of Acariformes mites retained the ancestral pattern of mt gene arrangement of arthropods with slight modifications; 2) truncation of tRNAs for cysteine, phenylalanine and histidine occurred once in the most recent common ancestor of Acariformes mites whereas truncation of other tRNAs occurred multiple times; and 3) the placement of eriophyoid mites in the order Trombidiformes needs to be reviewed.

  3. Introgression of leaf rust and stripe rust resistance from Sharon goatgrass (Aegilops sharonensis Eig) into bread wheat (Triticum aestivum L.).

    Science.gov (United States)

    Millet, E; Manisterski, J; Ben-Yehuda, P; Distelfeld, A; Deek, J; Wan, A; Chen, X; Steffenson, B J

    2014-06-01

    Leaf rust and stripe rust are devastating wheat diseases, causing significant yield losses in many regions of the world. The use of resistant varieties is the most efficient way to protect wheat crops from these diseases. Sharon goatgrass (Aegilops sharonensis or AES), which is a diploid wild relative of wheat, exhibits a high frequency of leaf and stripe rust resistance. We used the resistant AES accession TH548 and induced homoeologous recombination by the ph1b allele to obtain resistant wheat recombinant lines carrying AES chromosome segments in the genetic background of the spring wheat cultivar Galil. The gametocidal effect from AES was overcome by using an "anti-gametocidal" wheat mutant. These recombinant lines were found resistant to highly virulent races of the leaf and stripe rust pathogens in Israel and the United States. Molecular DArT analysis of the different recombinant lines revealed different lengths of AES segments on wheat chromosome 6B, which indicates the location of both resistance genes.

  4. Comparison of FTIR spectra between Huanglongbing (citrus greening) and other citrus maladies.

    Science.gov (United States)

    Hawkins, Samantha A; Park, Bosoon; Poole, Gavin H; Gottwald, Tim R; Windham, William R; Albano, Joseph; Lawrence, Kurt C

    2010-05-26

    Fourier transform infrared (FTIR) spectroscopy has the ability to quickly identify the presence of specific carbohydrates in plant materials. The presence of the disease huanglongbing (HLB) in the leaves of infected citrus plants has a distinctive spectrum that can be used to distinguish an infected plant from a healthy plant. However, many citrus diseases display similar visible symptoms and are of concern to citrus growers. In this study several citrus diseases (citrus leaf rugose virus, citrus tristeza virus, citrus psorosis virus, and Xanthomonas axonopodis ) and nutrient deficiencies (iron, copper, zinc, manganese, and magnesium) were compared with HLB using FTIR spectroscopy to determine if the spectra alone can be used to identify plants that are infected with HLB instead of another disease. The results indicate that the spectra of some diseases and deficiencies more closely resemble those of apparently healthy plants and some share the carbohydrate transformation that has been seen in the spectra of HLB-infected plants.

  5. Haematophagus Mites in Poultry Farms of Iran

    Directory of Open Access Journals (Sweden)

    S Rahbari

    2009-12-01

    Full Text Available Background: Blood sucking mites are important avian ectoparasites which being found on bird species worldwide. Their presence are problematic for the producers either through potential direct effects on weight gain, egg produc­tion, sperm production in roosters or as nuisance pests on worker handle hens and eggs. The aim of this study was pointing out of the status of haematophagus mites."nMethods: Eight caged layer and four breeder flocks were visited, monitoring for the presence of chicken mites per­formed by removing and examining debris from poultry house, infested nesting material collected into zip lock plas­tic bags and at least 20 birds were also randomly selected to examine the presence of chicken mites. Mites obtained from each population were mounted in Hoyer,s medium on microscope slides and identified. All eight caged layer and four breeder flocks were inspected, which were infested with chicken blood feeding mites."nResults: Massive infestations of Dermanyssus gallinae were common with huge numbers of parasites on birds, cages and the conveyor belts for egg. Only one farm from Mazandaran Province was infested to Ornithonyssus bursa."nConclusion: Dermanyssus gallinae was the most prevalent blood feeder mite in the breeder and caged layer flocks in Iran, while O. bursa was reported as a first record, which found only in a breeder flock in Mazanderan Province. It seems that its presence is limited into the area which affected by both warm and humid environmental conditions.  Keywords: Dermanyssus gallinae, Ornithonyssus bursa, Poultry, Iran

  6. Identification and mapping of leaf, stem and stripe rust resistance quantitative trait loci and their interactions in durum wheat.

    Science.gov (United States)

    Singh, A; Pandey, M P; Singh, A K; Knox, R E; Ammar, K; Clarke, J M; Clarke, F R; Singh, R P; Pozniak, C J; Depauw, R M; McCallum, B D; Cuthbert, R D; Randhawa, H S; Fetch, T G

    2013-02-01

    Leaf rust (Puccinia triticina Eriks.), stripe rust (Puccinia striiformis f. tritici Eriks.) and stem rust (Puccinia graminis f. sp. tritici) cause major production losses in durum wheat (Triticum turgidum L. var. durum). The objective of this research was to identify and map leaf, stripe and stem rust resistance loci from the French cultivar Sachem and Canadian cultivar Strongfield. A doubled haploid population from Sachem/Strongfield and parents were phenotyped for seedling reaction to leaf rust races BBG/BN and BBG/BP and adult plant response was determined in three field rust nurseries near El Batan, Obregon and Toluca, Mexico. Stripe rust response was recorded in 2009 and 2011 nurseries near Toluca and near Njoro, Kenya in 2010. Response to stem rust was recorded in field nurseries near Njoro, Kenya, in 2010 and 2011. Sachem was resistant to leaf, stripe and stem rust. A major leaf rust quantitative trait locus (QTL) was identified on chromosome 7B at Xgwm146 in Sachem. In the same region on 7B, a stripe rust QTL was identified in Strongfield. Leaf and stripe rust QTL around DArT marker wPt3451 were identified on chromosome 1B. On chromosome 2B, a significant leaf rust QTL was detected conferred by Strongfield, and at the same QTL, a Yr gene derived from Sachem conferred resistance. Significant stem rust resistance QTL were detected on chromosome 4B. Consistent interactions among loci for resistance to each rust type across nurseries were detected, especially for leaf rust QTL on 7B. Sachem and Strongfield offer useful sources of rust resistance genes for durum rust breeding.

  7. Green synthesis of gold nanoparticles using Citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) aqueous extract and its characterization.

    Science.gov (United States)

    Sujitha, Mohanan V; Kannan, Soundarapandian

    2013-02-01

    This study reports the biological synthesis of gold nanoparticles by the reduction of HAuCl(4) by using citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) juice extract as the reducing and stabilizing agent. A various shape and size of gold nanoparticles were formed when the ratio of the reactants were altered with respect to 1.0mM chloroauric acid solution. The gold nanoparticles obtained were characterized by UV-visible spectra, transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM studies showed the particles to be of various shapes and sizes and particle size ranges from 15 to 80 nm. Selected-area electron diffraction (SAED) pattern confirmed fcc phase and crystallinity of the particles. The X-ray diffraction analysis revealed the distinctive facets (111, 200, 220 and 222 planes) of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size for colloid gp(3) of C. limon, C. reticulata and C. sinensis are 32.2 nm, 43.4 nm and 56.7 nm respectively. The DLS graph showed that the particles size was larger and more polydispersed compared to the one observed by TEM due to the fact that the measured size also includes the bio-organic compounds enveloping the core of the Au NPs. Zeta potential value for gold nanoparticles obtained from colloid gp(3) of C. limon, C. reticulata and C. sinensis are -45.9, -37.9 and -31.4 respectively indicating the stability of the synthesized nanoparticles. Herein we propose a novel, previously unexploited method for the biological syntheses of polymorphic gold nanoparticles with potent biological applications.

  8. Green synthesis of gold nanoparticles using Citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) aqueous extract and its characterization

    Science.gov (United States)

    Sujitha, Mohanan V.; Kannan, Soundarapandian

    2013-02-01

    This study reports the biological synthesis of gold nanoparticles by the reduction of HAuCl4 by using citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) juice extract as the reducing and stabilizing agent. A various shape and size of gold nanoparticles were formed when the ratio of the reactants were altered with respect to 1.0 mM chloroauric acid solution. The gold nanoparticles obtained were characterized by UV-visible spectra, transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM studies showed the particles to be of various shapes and sizes and particle size ranges from 15 to 80 nm. Selected-area electron diffraction (SAED) pattern confirmed fcc phase and crystallinity of the particles. The X-ray diffraction analysis revealed the distinctive facets (1 1 1, 2 0 0, 2 2 0 and 2 2 2 planes) of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size for colloid gp3 of C. limon, C. reticulata and C. sinensis are 32.2 nm, 43.4 nm and 56.7 nm respectively. The DLS graph showed that the particles size was larger and more polydispersed compared to the one observed by TEM due to the fact that the measured size also includes the bio-organic compounds enveloping the core of the Au NPs. Zeta potential value for gold nanoparticles obtained from colloid gp3 of C. limon, C. reticulata and C. sinensis are -45.9, -37.9 and -31.4 respectively indicating the stability of the synthesized nanoparticles. Herein we propose a novel, previously unexploited method for the biological syntheses of polymorphic gold nanoparticles with potent biological applications.

  9. 金属防锈剂的防锈性能及试验验证%Anti-Rust Properties and Test Validation of Metal Anti-Rust Agents

    Institute of Scientific and Technical Information of China (English)

    侯万果; 王子君; 田前进

    2014-01-01

    The effects of types of anti-rust agents,surfactants,water quality and pH on anti-rust properties of metal anti-rust agents are discussed through analyzing anti-rust mechanism for metal anti-rust agents,and the test verifi-cation is conducted.The results show that in a certain range,the anti-rust properties of metal anti-rust agents with the same or similar molecular structure are improved with the growth of carbon chain.When the molecular structure contains a hydrophobic hydrocarbon group of appropriate length,the anti -rust properties are improved with the in-crease of polar group.The certain surfactants will reduce the anti-rust properties of anti-rust agents.With respect to the distilled water,the tap water reduces the anti-rust properties of metal anti-rust agents.The metal anti-rust a-gents have good anti-rust effect on the 10#steel,brass and aluminum LY12 as pH is 8~8.5.%通过分析金属防锈剂的防锈机理,探讨了防锈剂种类、表面活性剂、水质和 pH值对金属防锈剂防锈性能的影响,并进行了试验验证。结果表明,在一定范围内相同或相似分子结构金属防锈剂的防锈性能随碳链的增长而不断提高;当分子结构中含有适当长度疏水性烃基时,其防锈性能随极性基团的增加而有所提高;某些表面活性剂会降低防锈剂的防锈性能;相对于蒸馏水,自来水则会削弱金属防锈剂的防锈性能;pH值为8~8.5时金属防锈剂对10#钢、黄铜和LY12铝均有较好的防锈效果。

  10. Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines, and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2014-10-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the families Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) in central and south central Florida. Inner and outer canopy leaves, fruit, twigs, and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. Two species of eupalopsellid mites (Exothorhis caudata Summers and Saniosulus harteni (van-Dis and Ueckermann)) were identified from 252 specimens collected within citrus tree canopies within the seven citrus orchards of which 249 were E. caudata. Only two E. caudata were collected from ground cover plants within five of the seven orchards. Eight species of Stigmaeidae were identified from 5,637 specimens: Agistemus floridanus Gonzalez, A. terminalis Gonzalez, Eustigmaeus arcuata (Chandhri), E. sp. near arcuata, E. segnis (Koch), Mediostigmaeus citri (Rakha and McCoy), Stigmaeus seminudus Wood, and Zetzellia languida Gonzalez were collected from within citrus tree canopies from seven orchard sites. Agistemus floridanus was the only species in either family that was abundant with 5,483 collected from within citrus tree canopies compared with only 39 from vine or ground cover plants. A total of 431 samples from one or more of 82 vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards and one or more eupalopsellids or stigmaeids were collected from 19 of these plants. Richardia brasiliensis (Meg.) Gomez had nine A. floridanus from 5 of 25 samples collected from this plant. Solanum sp. had five A. floridanus from three samples taken. Both eupalopsellid and stigmaeid species numbers represented orchards were on full herbicide programs and ground cover plants were absent. Agistemus floridanus was more abundant in the citrus orchards with on-going or recent herbicide programs compared with orchards having well-developed ground

  11. Plant resistance within the Rutaceae to Asian citrus psyllid

    Science.gov (United States)

    USDA-ARS recently initiated research on host plant resistance to the Asian citrus psyllid. The psyllid is an important invasive pest of citrus in the United States because it transmits a serious disease of citrus known as huanglongbing (citrus greening). There is no cure for this bacterial disease. ...

  12. 7 CFR 319.56-38 - Citrus from Chile.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Chile. 319.56-38 Section 319.56-38... from Chile. Clementines (Citrus reticulata Blanco var. Clementine), mandarins (Citrus reticulata Blanco), and tangerines (Citrus reticulata Blanco) may be imported into the United States from Chile,...

  13. A comparison of plant species for rearing Asian citrus psyllid

    Science.gov (United States)

    Five plant genotypes were compared with respect to Asian citrus psyllid (ACP) reproduction potential: Bergera koenigii, Citrus aurantiifolia, C. macrophylla, C. taiwanica and Murraya paniculata. Asian citrus psyllid reproduction is dependent on young flush and thus Asian citrus psyllid production po...

  14. New Rust Disease of Korean Willow (Salix koreensis) Caused by Melampsora yezoensis, Unrecorded Pathogen in Korea.

    Science.gov (United States)

    Yun, Yeo Hong; Ahn, Geum Ran; Yoon, Seong Kwon; Kim, Hoo Hyun; Son, Seung Yeol; Kim, Seong Hwan

    2016-12-01

    During the growing season of 2015, leaf specimens with yellow rust spots were collected from Salix koreensis Andersson, known as Korean willow, in riverine areas in Cheonan, Korea. The fungus on S. koreensis was identified as the rust species, Melampsora yezoensis, based on the morphology of urediniospores observed by light and scanning electron microscopy, and the molecular properties of the internal transcribed spacer rDNA region. Pathogenicity tests confirmed that the urediniospores are the causal agent of the rust symptoms on the leaves and young stems of S. koreensis. Here, we report a new rust disease of S. koreensis caused by the rust fungus, M. yezoensis, a previously unrecorded rust pathogen in Korea.

  15. Advances in Localization and Molecular Markers of Wheat Leaf Rust Resistance Genes

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-xiang; LIU Da-qun

    2004-01-01

    Genetic resistance is the most economical method of reducing yield losses caused by wheat leaf rust. To identify the leaf rust resistance genes in commonly used parental germplasm and released cultivars become very important for utilizing the genetic resistance tc wheat leaf rust fully. Up to date, about 90 leaf rust resistance genes have been found,of which 51 genes have been located and mapped to special chromosomes, and 56 genes have been designated officially according to the standards set forth in the Catalogue of Gene Symbols for wheat. Twenty-four wheat leaf rust resistance genes have been developed for their molecular markers. It is very important to isolate, characterize, and map leaf rust resistance genes due to the resistance losses of the genes caused by the pathogen continuously.

  16. Cryopreservation and Cryotherapy of Citrus Cultivars

    Science.gov (United States)

    Long-term conservation of Citrus clones can be accomplished by cryopreservation. Shoot tips will survive liquid nitrogen exposure and storage when appropriately desiccated and treated with cryoprotectant solutions. In our research, vegetative Citrus budwood is shipped from Riverside to Fort Collin...

  17. Citrus water use in South Africa

    CSIR Research Space (South Africa)

    Vahrmeijer, JT

    2012-09-01

    Full Text Available intervenes through policy instruments to influence water use behaviour. Citrus growers need to take heed of these changes in policy as the majority of citrus orchards are irrigated and more detailed information on seasonal water requirements and irrigation...

  18. Understanding the dynamics of citrus water use

    CSIR Research Space (South Africa)

    Taylor, NJ

    2012-12-01

    Full Text Available The quantification of water use of citrus orchards is important in order to prevent stress developing in the orchard and to avoid wasting precious water resources. Measurement of citrus orchard water use is not possible under all environ...

  19. Rapid cyling plant breeding in citrus

    Science.gov (United States)

    Resistance or tolerance to huanglongbing (HLB) and other important traits have been identified in several citrus types and relatives and associated markers should be identified soon. What is urgently needed in addition is an accelerated strategy for citrus variety breeding. Identification and use of...

  20. Enzymatic activity in extracts of allergy-causing astigmatid mites.

    Science.gov (United States)

    Morgan, Marjorie S; Arlian, Larry G

    2006-11-01

    Many of the previously characterized allergens of house dust mites are known to be proteases, and this enzymatic activity is thought to contribute to their allergenicity. Other astigmatid mites, including stored-product mites and the ectoparasitic itch mite, Sarcoptes scabiei De Geer, are also known to be allergenic, but little or nothing is known about their enzymatic activities. The purpose of this study was to characterize the enzymatic activities present in extracts of the parasitic itch mite and from eight other species of free-living astigmatid mites. Extracts were prepared from one parasitic mite (S. scabiei), five stored-product mites (Chortoglyphus arcuatus (Troupeau), Lepidoglyphus destructor (Schrank), Blomia tropicalis Bronswijk, Cock, Oshima, Tyrophagus putrescentiae (Schrank), and Acarus siro L.), and three house dust mites [Dermatophagoidesfarinae Hughes, Dermatophagoides pteronyssinus (Troussart), and Euroglyphus maynei (Cooreman) ]. ApiZym strips were used to screen for the presence of 19 individual enzyme activities. Digestion of nine other substrates was evaluated by spectrophotometric or electrophoretic methods. All mite extracts exhibited some form of phosphatase, esterase, aminopeptidase, and glycosidase activity, although their substrate specificities varied considerably. Itch mite extract did not possess detectable serine peptidase activity nor was it able to hydrolyze gelatin or casein, whereas all other mite extracts exhibited these activities. Storage mite extracts possessed enzymes capable of degrading the widest range of substrates, whereas itch mite extract had the most limited proteolytic capacity. Extracts of nine species of allergy-causing astigmatid mites contain wide and diverse repertoires of enzymatic activities. These catalytic activities may be important contributors to the induction and manifestation of inflammatory and immune responses to mites in patients.

  1. Citrus quarantine, sanitary and certification programs in the USA. Prevention of introduction and distribution of citrus diseases

    Science.gov (United States)

    Citrus germplasm originated in Australasia, the Far East, and Africa, thus all citrus grown in the New World was imported. This importation of citrus also resulted in importation of graft transmissible pathogens of citrus, many of which are latent in their original host but can cause epidemics of t...

  2. Acaricides and predatory mites against the begonia mite, Polyphagotarsonemus latus (Acari: Tarsonemidae), on Hedera helix.

    Science.gov (United States)

    Audenaert, Joachim; Vissers, Marc; Haleydt, Bart; Verhoeven, Ruth; Goossens, Frans; Gobin, Bruno

    2009-01-01

    In recent years, the begonia mite (Polyphagotarsonemus lotus) has become an important threat to different ornamental cultures in warm greenhouses. At present there are no professional plant protection products registered in Belgium for the control of mites of the Tarsonemidae family. In a screening trial, we evaluated the efficacy of a range of different acaricides: abamectin, milbemectin, pyridaben, spirodiclofen. Based on the results of the screening trial several products were selected for a full efficacy trial following EPPO guidelines. The best control results were obtained with two products from the avermectine group: abamectin and milbemectin. As growers currently have to rely solely on the use of natural enemies there is a strong need for practical evaluation of efficacies of the various predatory mite species (Amblyseius swirskii, A. cucumeris, A. andersoni) used in biological mite control. In a series of experiments, we screened the use of different species of predatory mites. The first efficacy trials on heavily infested plants at different rates of dosage and under different circumstances (temperature, dose rate, application technique) were started in May 2008. In these experiments Amblyseius swirskii showed good efficacy. But temperature was the limiting factor: the predatory mite needed a minimal temperature of 18 degrees C to obtain good results. Further research is necessary to search for predatory mites that can be used in winter conditions (lower temperatures, less light).

  3. The WRKY Transcription Factor Family in Citrus: Valuable and Useful Candidate Genes for Citrus Breeding.

    Science.gov (United States)

    Ayadi, M; Hanana, M; Kharrat, N; Merchaoui, H; Marzoug, R Ben; Lauvergeat, V; Rebaï, A; Mzid, R

    2016-10-01

    WRKY transcription factors belong to a large family of plant transcriptional regulators whose members have been reported to be involved in a wide range of biological roles including plant development, adaptation to environmental constraints and response to several diseases. However, little or poor information is available about WRKY's in Citrus. The recent release of completely assembled genomes sequences of Citrus sinensis and Citrus clementina and the availability of ESTs sequences from other citrus species allowed us to perform a genome survey for Citrus WRKY proteins. In the present study, we identified 100 WRKY members from C. sinensis (51), C. clementina (48) and Citrus unshiu (1), and analyzed their chromosomal distribution, gene structure, gene duplication, syntenic relation and phylogenetic analysis. A phylogenetic tree of 100 Citrus WRKY sequences with their orthologs from Arabidopsis has distinguished seven groups. The CsWRKY genes were distributed across all ten sweet orange chromosomes. A comprehensive approach and an integrative analysis of Citrus WRKY gene expression revealed variable profiles of expression within tissues and stress conditions indicating functional diversification. Thus, candidate Citrus WRKY genes have been proposed as potentially involved in fruit acidification, essential oil biosynthesis and abiotic/biotic stress tolerance. Our results provided essential prerequisites for further WRKY genes cloning and functional analysis with an aim of citrus crop improvement.

  4. House dust mites in Brazil - an annotated bibliography

    Directory of Open Access Journals (Sweden)

    Binotti Raquel S

    2001-01-01

    Full Text Available House dust mites have been reported to be the most important allergen in human dwellings. Several articles had already shown the presence of different mite species at homes in Brazil, being Pyroglyphidae, Glycyphagidae and Cheyletidae the most important families found. This paper is an annotated bibliography that will lead to a better knowledge of house dust mite fauna in Brazil.

  5. Does the removal of mite-infested brood facilitate grooming?

    Science.gov (United States)

    The relationship between the removal of mite-infested brood and mite drop was compared using Russian (RHB, n = 9) and Italian (IHB, n = 9) honey bee colonies. A cloake board was used to isolate test brood frame on the top hive body and the metal sheet served as a varroa trap. Inoculum mites were col...

  6. Mites associated with bark beetles and their hyperphoretic ophiostomatoid fungi

    Science.gov (United States)

    Richard W. Hofstetter; John Moser; Stacy Blomquist

    2014-01-01

    The role that mites play in many ecosystems is often overlooked or ignored. Within bark beetle habitats, more than 100 mite species exist and they have important impacts on community dynamics, ecosystem processes, and biodiversity of bark beetle systems. Mites use bark beetles to access and disperse among beetle-infested trees and the associations may range from...

  7. Limiting factors for growth and development of domestic mites

    NARCIS (Netherlands)

    Lynden, A.M.T. van; Kort, H.S.M.; Koren, L.G.H.; Pernot, C.E.E.; Bronswijk, J.E.M.H. van

    1996-01-01

    A quarter to half of European households are at risk of health damage due to mites in their home. House dust mites (family Pyroglyphidae) and storage mites (families Acaridae and Gly-cyphagidae) are present; both groups being specific for different ecosystems: house-dust ecosystem of textiles (house

  8. Effect of stripe rust on the yield response of wheat to nitrogen

    Institute of Scientific and Technical Information of China (English)

    Rakhesh; Devadas; Steven; Simpfendorfer; David; Backhouse; David; W.Lamb

    2014-01-01

    Nitrogen(N) is the most important fertiliser element determining the productivity of wheat.N nutrition is known to affect the level of stripe rust infection, with higher N associated with increased disease severity. Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a major yield-limiting disease of wheat in Australia. This paper describes experiments designed to investigate the agronomic response to the interaction of various levels of N application and stripe rust severity in wheat varieties differing in response. Experimental plots were established in crop seasons 2006 and 2007 on the Liverpool Plains of northern NSW, Australia.Yield, biomass, grain protein content(GPC) and harvest index(HI) data were recorded.Increased rates of N increased the severity of stripe rust during grain filling. N application also increased yield and GPC in all varieties in both years. Stripe rust reduced the yield of the rust-susceptible wheat varieties, and GPC and proportion of added N recovered in the grain were also reduced in one year but not the other. It was evident from our experiment that stripe rust caused yield loss accompanied by either no change or reduction in GPC, indicating that the total amount of N entering the grain was reduced by stripe rust. The effects of stripe rust on N yield are most likely associated with reduced uptake of N during grain filling.

  9. An analysis of the risk of introduction of additional strains of the rust puccinia psidii Winter ('Ohi'a Rust) to Hawai'i

    Science.gov (United States)

    Loope, Lloyd; La Rosa, Anne Marie

    2010-01-01

    In April 2005, the rust fungus Puccinia psidii (most widely known as guava rust or eucalyptus rust) was found in Hawai'i. This was the first time this rust had been found outside the Neotropics (broadly-defined, including subtropical Florida, where the rust first established in the 1970s). First detected on a nursery-grown 'ohi'a plant, it became known as ''ohi'a rust'in Hawai'i. The rust spread rapidly and by August 2005 had been found throughout the main Hawaiian Islands. The rust probably reached Hawai'i via the live plant trade or via the foliage trade. In Hawai'i, the rust has infected three native plant species and at least eight non-native species. Effects have been substantial on the endangered endemic plant Eugenia koolauensis and the introduced rose apple, Syzygium jambos. Billions of yellow, asexual urediniospores are produced on rose apple, but a complete life cycle (involving sexual reproduction) has not yet been observed. The rust is autoecious (no alternate host known) on Myrtaceae. The strain introduced into Hawai'i is found sparingly on 'ohi'a (Metrosideros polymorpha), the dominant tree of Hawai'i's forests, with sporadic damage detected to date. The introduction of a rust strain that causes widespread damage to 'ohi'a would be catastrophic for Hawai'i's native biodiversity. Most imports of material potentially contaminated with rust are shipped to Hawai'i from Florida and California (from which P. psidii was reported in late 2005 by Mellano, 2006). Florida is known to have multiple strains. The identity of the strain or strains in California is unclear, but one of them is known to infect myrtle, Myrtus communis, a species commonly imported into Hawai'i. It is important to ecosystem conservation and commercial forestry that additional rust strains or genotypes be prevented from establishing in Hawai'i. The purpose of this analysis of risk is to evaluate the need for an interim rule by the Hawai'i Department of Agriculture to regulate plant

  10. What can the programming language Rust do for astrophysics?

    Science.gov (United States)

    Blanco-Cuaresma, Sergi; Bolmont, Emeline

    2017-06-01

    The astrophysics community uses different tools for computational tasks such as complex systems simulations, radiative transfer calculations or big data. Programming languages like Fortran, C or C++ are commonly present in these tools and, generally, the language choice was made based on the need for performance. However, this comes at a cost: safety. For instance, a common source of error is the access to invalid memory regions, which produces random execution behaviors and affects the scientific interpretation of the results. In 2015, Mozilla Research released the first stable version of a new programming language named Rust. Many features make this new language attractive for the scientific community, it is open source and it guarantees memory safety while offering zero-cost abstraction. We explore the advantages and drawbacks of Rust for astrophysics by re-implementing the fundamental parts of Mercury-T, a Fortran code that simulates the dynamical and tidal evolution of multi-planet systems.

  11. [Mites allergy in children from Tula region].

    Science.gov (United States)

    Zlobina, Zh M; Pron'kina, O V; Khlgatian, S V; Berzhets, A I; Berzhets, V M

    2006-01-01

    Characteristics of allergy to mites in children living in Tula region have been revealed. It was shown that mites from Pyroglyphidae (Dermatophagoides pteronyssinus, Dermatophagoides farinae), Cheyletidae and Glycyphagidae (G. destructor, G. domesticus) families play important role in development of atopic allergy in children from this region. Efficacy of plant-origin acaricide "Milbiol" as part of prophylactic measures was evaluated. Its use in children with mild and intermediate asthma led to decrease of number of wheezing episodes, improvement of respiratory function, lessening of clinical signs of allergic rhinitis, decrease or discontinuation of usage of vasoconstrictive preparations.

  12. Improved annotation of the insect vector of citrus greening disease: Biocuration by a diverse genomics community

    Science.gov (United States)

    The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the pathogen associated with citrus Huanglongbing (HLB, citrus greening). HLB threatens citrus production worldwide. Suppression or reduction of the insect vector usin...

  13. Annotation of the Asian citrus psyllid genome reveals a reduced innate immune system

    Science.gov (United States)

    Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuway...

  14. Influence of lactate ions on the formation of rust

    Energy Technology Data Exchange (ETDEWEB)

    Sabot, R. [Laboratoire d' Etude des Materiaux en Milieux Agressifs, EA 3167, Universite de La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France); Jeannin, M. [Laboratoire d' Etude des Materiaux en Milieux Agressifs, EA 3167, Universite de La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France); Gadouleau, M. [Laboratoire d' Etude des Materiaux en Milieux Agressifs, EA 3167, Universite de La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France); Guo, Q. [Laboratoire d' Etude des Materiaux en Milieux Agressifs, EA 3167, Universite de La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France); Sicre, E. [Laboratoire d' Etude des Materiaux en Milieux Agressifs, EA 3167, Universite de La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France); Refait, Ph. [Laboratoire d' Etude des Materiaux en Milieux Agressifs, EA 3167, Universite de La Rochelle, Bat. Marie Curie, Avenue Michel Crepeau, F-17042 La Rochelle cedex 01 (France)]. E-mail: prefait@univ-lr.fr

    2007-03-15

    The formation of rust can be simulated by oxidation of aqueous suspensions of Fe(OH){sub 2} obtained by mixing solutions of NaOH and a Fe(II) salt. The aim of this study was to investigate the influence of organic species associated with microbially influenced corrosion. The lactate anion, often used as a carbon and electrons source for the development of microorganisms, was chosen as an example. Then, in the first part of the study, Fe(OH){sub 2} was precipitated using iron(II) lactate and NaOH. Its oxidation process involved two stages, as usually observed. The first stage led to a Fe(II-III) intermediate compound, the lactate green rust, GR(C{sub 3}H{sub 5}O{sub 3}{sup -}). This compound has never been reported yet. Its existence demonstrates that the GR structure is able to incorporate a very wide range of anions, whatever the size and geometry. The second stage corresponded to the oxidation of GR(C{sub 3}H{sub 5}O{sub 3}{sup -}). It led to ferrihydrite, the most poorly ordered form of iron(III) oxides and oxyhydroxides. In the second part of the study, the formation of rust in seawater was simulated by oxidation of Fe(OH){sub 2} in an aqueous media containing both Cl{sup -} and SO{sub 4}{sup 2-} anions. The first stage led to the sulphate green rust, GR(SO{sub 4}{sup 2-}), the second stage to lepidocrocite {gamma}-FeOOH. Small amounts of iron(II) lactate were added to the reactants. Lactate ions did not modify the first stage but drastically perturbed the second stage, as ferrihydrite was obtained instead of {gamma}-FeOOH.

  15. The past, present and future of breeding rust resistant wheat

    Directory of Open Access Journals (Sweden)

    Jeffrey G Ellis

    2014-11-01

    Full Text Available Two classes of genes are used for breeding rust resistant wheat. The first class, called R (for resistance genes, are pathogen race-specific in their action, effective at all plant growth stages and probably mostly encode immune receptors of the nucleotide binding leucine rich repeat (NB-LRR class. The second class called Adult Plant Resistance genes (APR because resistance is usually functional only in adult plants, and, in contrast to most R genes, the levels of resistance conferred by single APR genes are only partial and allow considerable disease development. Some but not all APR genes provide resistance to all isolates of a rust pathogen species and a subclass of these provides resistance to several fungal pathogen species. Initial indications are that APR genes encode a more heterogeneous range of proteins than R proteins. Two APR genes, Lr34 and Yr36, have been cloned from wheat and their products are an ABC transporter and a protein kinase, respectively. Lr34 and Sr2 have provided long lasting and widely used (durable partial resistance and are mainly used in conjunction with other R and APR genes to obtain adequate rust resistance. We caution that some APR genes indeed include race-specific, weak R genes which may be of the NB-LRR class. A research priority to better inform rust resistance breeding is to characterize further APR genes in wheat and to understand how they function and how they interact when multiple APR and R genes are stacked in a single genotype by conventional and GM breeding. An important message is do not be complacent about the general durability of all APR genes.

  16. Resistance of alloplasmic wheats to brown leaf rust

    Directory of Open Access Journals (Sweden)

    Alexander Lvovivh SECHNYAK

    2010-11-01

    Full Text Available The reaction of alloplasmic and euplasmic lines of wheat on brown leaf rust was studied in the condition of field infectious nursery in 2002, 2004, 2006 and 2007. The influence of cytoplasmic genome on resistance of the investigated lines varied for years and probably was mainly specific to race. However the positive effect of alloplasm from Aegilops squarrosa var. typica on resistance to pathogene was stable and universal.

  17. Dust mites in a routine clinical stool sample

    Institute of Scientific and Technical Information of China (English)

    Bushra Zia; Hassaan Bin Aftab; Mohammad Faizan Zahid; Joveria Farooqi; Feroze Uddin; Mohammad Asim Beg

    2014-01-01

    We report a case of dust mite carriage in a 56-year-old gentleman. Dust mites eggs and larvae were found in a stool sample which was taken for a routine clinical examination. He was completely asymptomatic with no history of rash, airway disease or other allergic manifestations associated with dust mites. We noticed that the oval structure of mite eggs resembled helminth eggs and therefore may be misidentified during routine clinical analysis. As the patient was otherwise healthy, it was concluded that no rigorous antiparasitic therapy was necessary to eliminate dust mites from his system.

  18. Signaling pathways in a Citrus EST database

    Directory of Open Access Journals (Sweden)

    Angela Mehta

    2007-01-01

    Full Text Available Citrus spp. are economically important crops, which in Brazil are grown mainly in the State of São Paulo. Citrus cultures are attacked by several pathogens, causing severe yield losses. In order to better understand this culture, the Millenium Project (IAC Cordeirópolis was launched in order to sequence Citrus ESTs (expressed sequence tags from different tissues, including leaf, bark, fruit, root and flower. Plants were submitted to biotic and abiotic stresses and investigated under different development stages (adult vs. juvenile. Several cDNA libraries were constructed and the sequences obtained formed the Citrus ESTs database with almost 200,000 sequences. Searches were performed in the Citrus database to investigate the presence of different signaling pathway components. Several of the genes involved in the signaling of sugar, calcium, cytokinin, plant hormones, inositol phosphate, MAPKinase and COP9 were found in the citrus genome and are discussed in this paper. The results obtained may indicate that similar mechanisms described in other plants, such as Arabidopsis, occur in citrus. Further experimental studies must be conducted in order to understand the different signaling pathways present.

  19. Citrus breeding, genetics and genomics in Japan

    Science.gov (United States)

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering. PMID:27069387

  20. Citrus breeding, genetics and genomics in Japan.

    Science.gov (United States)

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering.

  1. Assessment of imperfect detection of blister rust in whitebark pine within the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Wright, Wilson J.; Irvine, Kathryn M.

    2017-01-01

    We examined data on white pine blister rust (blister rust) collected during the monitoring of whitebark pine trees in the Greater Yellowstone Ecosystem (from 2004-2015). Summaries of repeat observations performed by multiple independent observers are reviewed and discussed. These summaries show variability among observers and the potential for errors being made in blister rust status. Based on this assessment, we utilized occupancy models to analyze blister rust prevalence while explicitly accounting for imperfect detection. Available covariates were used to model both the probability of a tree being infected with blister rust and the probability of an observer detecting the infection. The fitted model provided strong evidence that the probability of blister rust infection increases as tree diameter increases and decreases as site elevation increases. Most importantly, we found evidence of heterogeneity in detection probabilities related to tree size and average slope of a transect. These results suggested that detecting the presence of blister rust was more difficult in larger trees. Also, there was evidence that blister rust was easier to detect on transects located on steeper slopes. Our model accounted for potential impacts of observer experience on blister rust detection probabilities and also showed moderate variability among the different observers in their ability to detect blister rust. Based on these model results, we suggest that multiple observer sampling continue in future field seasons in order to allow blister rust prevalence estimates to be corrected for imperfect detection. We suggest that the multiple observer effort be spread out across many transects (instead of concentrated at a few each field season) while retaining the overall proportion of trees with multiple observers around 5-20%. Estimates of prevalence are confounded with detection unless it is explicitly accounted for in an analysis and we demonstrate how an occupancy model can be used

  2. The genome sequence and effector complement of the flax rust pathogen Melampsora lini

    Directory of Open Access Journals (Sweden)

    Adnane eNemri

    2014-03-01

    Full Text Available Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp. Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimise parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analysed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote

  3. The genome sequence and effector complement of the flax rust pathogen Melampsora lini

    Science.gov (United States)

    Nemri, Adnane; Saunders, Diane G. O.; Anderson, Claire; Upadhyaya, Narayana M.; Win, Joe; Lawrence, Gregory J.; Jones, David A.; Kamoun, Sophien; Ellis, Jeffrey G.; Dodds, Peter N.

    2014-01-01

    Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed most extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp). Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimize parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analyzed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote infection on their

  4. 78 FR 8435 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids and Fortunella

    Science.gov (United States)

    2013-02-06

    ... States through the importation of citrus fruit. These include two fruit flies, Anastrepha fraterculus... conditions are designed to prevent the introduction of the following quarantine pests: Anastrepha fraterculus...

  5. Identification and Validation of a Major Quantitative Trait Locus for Slow-rusting Resistance to Stripe Rust in Wheat

    Institute of Scientific and Technical Information of China (English)

    Xiaohua Cao; Jianghong Zhou; Xiaoping Gong; Guangyao Zhao; Jizeng Jia; Xiaoquan Qi

    2012-01-01

    Stripe (yellow) rust,caused by Puccinia striiformis Westend.f.sp.tritici Eriks (Pst),is one of the most important wheat (Triticum aestivum L.) diseases and causes significant yield losses.A recombinant inbred (RI) population derived from a cross between Yanzhan 1 and Xichang 76-9 cultivars was evaluated for resistance to wheat stripe rust strain CYR32 at both the seedling and adult plant stages.Four resistance quantitative trait loci (QTLs) were detected in this population,in which the major one,designated as Yrq1,was mapped on chromosome 2DS.The strategy of using the Brachypodium distachyon genome,wheat expressed sequence tags and a draft DNA sequences (scaffolds) of the D-genome (Aegilops tauschii Coss.) for the development of simple sequence repeat (SSR) markers was successfully used to identify 147 SSRs in hexaploid wheat.Of the 19 polymorphic SSRs in the RI population,17 SSRs were mapped in the homeologous group 2 chromosomes near Yrq1 region and eight SSRs were genetically mapped in the 2.7 cM region of Yrq1,providing abundant DNA markers for fine-mapping of Yrq1 and marker-assisted selection in wheat breeding program.The effectiveness of Yrq1 was validated in an independent population,indicating that this resistance QTL can be successfully transferred into a susceptible cultivar for improvement of stripe rust resistance.

  6. Comparison of antifungal activities of Vietnamese citrus essential oils.

    Science.gov (United States)

    Van Hung, Pham; Chi, Pham Thi Lan; Phi, Nguyen Thi Lan

    2013-03-01

    Citrus essential oils (EOs) are volatile compounds from citrus peels and widely used in perfumes, cosmetics, soaps and aromatherapy. In this study, inhibition of citrus EOs extracted from Vietnamese orange (Citrus sinensis), mandarin (Citrus reticulata Blanco), pomelo (Citrus grandis Osbeck) and lime (Citrus aurantifolia Swingle) on the growth of plant pathogenic fungi, Mucor hiemalis, Penicillium expansum and Fusarium proliferatum was investigated. The EOs of the citrus peels were obtained by cold-pressing method and the antifungal activity of EOs was evaluated using the agar dilution method. The results show that the EOs had significant antifungal activity. Lime EO was the best inhibitor of M. hiemalis and F. proliferatum while pomelo EO was the most effective against P. expansum. These results indicate that citrus EOs can be used as antifungal natural products in the food, pharmaceutical and cosmetic industries.

  7. MITE INCIDENCE AND CROP YIELD IN ZIMBABWE

    African Journals Online (AJOL)

    control, as well as damage and yield of tomatoes were investigated in two important tomato production areas of ... Mutoko, while the pruned and trellised plots had 4.6 and 17.3 mites per leaf. ..... therefore, insecticide deposit on the leaves was.

  8. En el límite

    Directory of Open Access Journals (Sweden)

    Reyes González, José Miguel

    1992-02-01

    Full Text Available Glass: technological limits, physical limits, existential limits as well? Inside or outside? Extreme or combined solutions? Glass architectures separating us from the exterior or uniting us with it? Ideal architectures or those adapted to the surroundings? Different energy costs for different solutions. A continually developing terrestrial atmosphere. Different geographies, artificial metropolis. Will we have to face the obligation to choose within the limits? Different architectures answering these questions are presented in this article.

    El vidrio: límite tecnológico, límite físico. ¿También límite existencial? ¿Dentro o fuera? ¿Soluciones extremas o soluciones mixtas? Arquitecturas de vidrio que nos separan o nos unen al exterior. Arquitecturas ideales, o adaptadas al medio circundante. Diferentes gastos de energía para diferentes planteamientos. Una atmósfera terrestre en continua evolución. Diferentes geografías y metrópolis artificiales. ¿Nos veremos obligados a elegir en el límite? Se exponen aquí diferentes arquitecturas que responden a estos distintos planteamientos.

  9. Respiratory allergy caused by house dust mites

    DEFF Research Database (Denmark)

    Calderón, Moisés A; Linneberg, Allan; Kleine-Tebbe, Jörg

    2015-01-01

    The house dust mite (HDM) is a major perennial allergen source and a significant cause of allergic rhinitis and allergic asthma. However, awareness of the condition remains generally low. This review assesses the links between exposure to HDM, development of the allergic response, and pathologic ...

  10. Major gene for field stem rust resistance co-locates with resistance gene Sr12 in "Thatcher" wheat

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis (Pgt), is a damaging disease of wheat that can be controlled by utilizing effecting stem rust resistance genes. "Thatcher" wheat carries complex resistance to stem rust that is enhanced in the presence of the resistance gene Lr34. The purpose of this study was ...

  11. First Report of Soybean Rust Caused by Phakopsora pachyrhizi in Ghana

    Science.gov (United States)

    Nigeria is the only country in West Africa where soybean rust, caused by Phakopsora pachyrhizi has been officially reported (1). During a disease survey in Ghana in October 2006, soybean (Glycine max) leaves with rust symptoms (tan, angular lesions with erumpent sori exuding urediniospores) were ob...

  12. Identification of Putative Coffee Rust Mycoparasites via Single-Molecule DNA Sequencing of Infected Pustules.

    Science.gov (United States)

    James, Timothy Y; Marino, John A; Perfecto, Ivette; Vandermeer, John

    2015-11-13

    The interaction of crop pests with their natural enemies is a fundament to their control. Natural enemies of fungal pathogens of crops are poorly known relative to those of insect pests, despite the diversity of fungal pathogens and their economic importance. Currently, many regions across Latin America are experiencing unprecedented epidemics of coffee rust (Hemileia vastatrix). Identification of natural enemies of coffee rust could aid in developing management strategies or in pinpointing species that could be used for biocontrol. In the present study, we characterized fungal communities associated with coffee rust lesions by single-molecule DNA sequencing of fungal rRNA gene bar codes from leaf discs (≈28 mm(2)) containing rust lesions and control discs with no rust lesions. The leaf disc communities were hyperdiverse in terms of fungi, with up to 69 operational taxonomic units (putative species) per control disc, and the diversity was only slightly reduced in rust-infected discs, with up to 63 putative species. However, geography had a greater influence on the fungal community than whether the disc was infected by coffee rust. Through comparisons between control and rust-infected leaf discs, as well as taxonomic criteria, we identified 15 putative mycoparasitic fungi. These fungi are concentrated in the fungal family Cordycipitaceae and the order Tremellales. These data emphasize the complexity of diverse fungi of unknown ecological function within a leaf that might influence plant disease epidemics or lead to the development of species for biocontrol of fungal disease.

  13. Morphology and AFLP markers suggest three Hordeum chilense ecotypes that differ in avoidance to rust fungi

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Aardse, A.; Buntjer, J.; Rubiales, D.; Martin, A.; Niks, R.E.

    2001-01-01

    In Hordeum chilense Roem. & Schult., a high variation in the level of avoidance to infection of barley leaf rust (Puccinia hordei Otth) occurs. Probably resulting from the properties of the stomata, the rust germ tube overgrows stomata, and the infection process fails in an early stage. In the prese

  14. Real-time PCR detection of Puccinia chrysanthemi causing brown rust of chrysanthemum

    Science.gov (United States)

    Fungi responsible for rust diseases are among the most challenging organisms to identify, as many identification keys are based on host identity. In the U.S., numerous rust fungi are quarantine-significant plant pathogens. As such, accurate identification is crucial to prevent the inadvertent introd...

  15. Resistance to white pine blister rust in Pinus flexilis and P

    Science.gov (United States)

    Anna W. Schoettle; Richard A. Sniezko; Angelia Kegley; Jerry Hill; Kelly S. Burns

    2010-01-01

    The non-native fungus Cronartium ribicola, that causes white pine blister rust (WPBR), is impacting or threatening limber pine, Pinus flexilis, and Rocky Mountain bristlecone pine, Pinus aristata. In the Southern Rockies, where the rust invasion is still expanding, we have the opportunity to be proactive and prepare the landscape for invasion. Genetic...

  16. Blister rust in North America: What we have not learned in the past 100 years

    Science.gov (United States)

    Eugene P. Van Arsdel; Brian W. Geils

    2011-01-01

    Introduction of Cronartium ribicola (white pine blister rust) greatly motivated development of tree disease control and research in America. Although foresters and pathologists have learned much in the past 100 years, more remains to learn. The most important lesson is that fear of blister rust has reduced pine regeneration more than the disease itself. Based on six...

  17. White pine blister rust resistance in limber pine: Evidence for a major gene

    Science.gov (United States)

    A. W. Schoettle; R. A. Sniezko; A. Kegley; K. S. Burns

    2014-01-01

    Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust caused by the non-native pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust will likely determine the potential success of restoration or proactive measures. These first extensive inoculation trials using individual tree seed collections...

  18. Low average blister-rust infection rates may mean high control costs

    Science.gov (United States)

    Robert Marty

    1965-01-01

    The Northeastern Forest Experiment Station, in cooperation with Federal and State forest-pest-control agencies, undertook a survey of blister-rust infection rates in the white pine region of the East during 1962 and 1963. Those engaged in blister-rust-control activities will not be surprised at the survey's results. We found that infection rates were significantly...

  19. Current and future molecular approaches to investigate the white pine blister rust pathosystem

    Science.gov (United States)

    B. A. Richardson; A. K. M. Ekramoddoulah; J.-J. Liu; M.-S. Kim; N. B. Klopfenstein

    2010-01-01

    Molecular genetics is proving to be especially useful for addressing a wide variety of research and management questions on the white pine blister rust pathosystem. White pine blister rust, caused by Cronartium ribicola, is an ideal model for studying biogeography, genetics, and evolution because: (1) it involves an introduced pathogen; (2) it includes multiple primary...

  20. Can microscale meteorological conditions predict the impact of white pine blister rust in Colorado and Wyoming?

    Science.gov (United States)

    William R. Jacobi; Betsy A. Goodrich; Holly S. J. Kearns; Kelly S. Burns; Brian W. Geils

    2011-01-01

    White pine blister rust occurs when there are compatible interactions between susceptible hosts (white pines and Ribes spp.), inoculum (Cronartium ribicola spores), and local weather conditions during infection. The five spore stages of the white pine blister rust (WPBR) fungus have specific temperature and moisture conditions necessary for production, germination, and...

  1. Biology and pathology of Ribes and their implications for management of white pine blister rust

    Science.gov (United States)

    P. J. Zambino

    2010-01-01

    Ribes (currants and gooseberries) are telial hosts for the introduced and invasive white pine blister rust fungus, Cronartium ribicola. Knowledge of wild and introduced Ribes helps us understand the epidemiology of blister rust on its aecial hosts, white pines, and develop disease control and management strategies. Ribes differ by species in their contribution to...

  2. Epistatic adult plant resistance in wheat to stem rust cosegregates with Sr12 seedling resistance

    Science.gov (United States)

    Wheat adult plant resistance (APR) to stem rust is desirable. Researchers have characterized the inheritance of APR in cultivar Thatcher as complex. In order to identify the loci providing APR in Thatcher, we evaluated 160 RILs derived from Thatcher/McNeal for stem rust reaction in the field in Keny...

  3. Disease management of leek rust : a study at field, farm and regional level

    NARCIS (Netherlands)

    Jong, de P.D.

    1995-01-01

    Leek rust, caused by Puccinia allii Rud., is an important disease of leek ( Allium porrum L.) in the Netherlands. The quality decrease of the product associated with a light infestation of leek rust may cause severe economic loss to the grower. The

  4. Differential response by Melaleuca quinquenervia trees to attack by the rust fungus Puccinia psidii in Florida

    Science.gov (United States)

    Melaleuca quinquenervia (melaleuca, paperbark tree) is an exotic invasive tree in Florida, Hawaii, and some Caribbean islands. Puccinia psidii (guava rust-fungus) is a Neotropical rust fungus, reported to attack many species in the Myrtaceae and one genus in the Heteropyxidaceae, both members of the...

  5. Disease management of leek rust, a study at field, farm and regional level.

    NARCIS (Netherlands)

    Jong, de P.D.

    1995-01-01

    Leek rust, caused by Puccinia allii Rud., is an important disease of leek ( Allium porrum L.) in the Netherlands. The quality decrease of the product associated with a light infestation of leek rust may cause severe economic loss to the grower. The aim of this study is to develop an improved pathosy

  6. Evaluation of Soybean Germplasm for Resistance to Soybean Rust in Vietnam

    Science.gov (United States)

    Soybean rust, caused by Phakopsora pachyrhizi Sydow, is a severe foliar disease of soybean [Glycine max (L.) Merr.] that occurs throughout most soybean producing regions of the world. Soybean rust may be managed with fungicides, but the utilization of soybean cultivars that are resistant to the path...

  7. A new rust disease on wild coffee (Psychotria nervosa) caused by Puccinia mysuruensis sp. nov

    Science.gov (United States)

    Psychotria nervosa, commonly called wild coffee (Rubiaceae) is an important ethno-medicinal plant in India. In 2010 a new rust disease of P. nervosa was observed in three regions of Mysore District, Karnataka (India) with disease incidence ranging from 58% to 63%. Typical symptoms of rust disease we...

  8. First report of Pantoea ananatis (Syn. Erwinia uredovora) being associated with peanut rust in Georgia

    Science.gov (United States)

    Peanut rust is caused by the fungus Puccinia arachidis. This disease, if not treated can cause severe damage and defoliation. While sequencing DNA of urediniospores of the rust fungus, BLAST analysis detected many sequences corresponding to the bacterial species Pantoea ananatis. This bacterium, ...

  9. Molecular tagging of a novel rust resistance gene R12 in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Sunflower production in North America has recently suffered economic losses in yield and seed quality from sunflower rust (Puccinia helianthi Schwein.) because of the increasing incidence and lack of resistance to new rust races. RHA 464, a newly released sunflower male fertility restorer line, is r...

  10. Unveiling common responses of Medicago truncatula to appropriate and inappropriate rust species

    Directory of Open Access Journals (Sweden)

    Maria Carlota eVaz Patto

    2014-11-01

    Full Text Available Little is known about the nature of effective defense mechanisms in legumes to pathogens of remotely related plant species. Some rust species are among pathogens with broad host range causing dramatic losses in various crop plants. To understand and compare the different host and nonhost resistance responses of legume species against rusts, we characterized the reaction of the model legume Medicago truncatula to one appropriate (Uromyces striatus and two inappropriate (U. viciae-fabae and U. lupinicolus rusts. We found that similar pre and post-haustorial mechanisms of resistance appear to be operative in M. truncatula against appropriate and inappropriate rust fungus. The appropriate U. striatus germinated better on M. truncatula accessions then the inappropriate U. viciae-fabae and U. lupinicolus, but once germinated, germ tubes of the three rusts had a similar level of success in finding stomata and forming an appressoria over a stoma. However responses to different inappropriate rust species also showed some specificity, suggesting a combination of non specific and specific responses underlying this legume nonhost resistance to rust fungi. Further genetic and expression analysis studies will contribute to the development of the necessary molecular tools to use the present information on host and nonhost resistance mechanisms to breed for broad-spectrum resistance to rust in legume species.

  11. Barberry rust survey – developing tools for diagnosis, analysis and data management

    DEFF Research Database (Denmark)

    Justesen, Annemarie Fejer; Hansen, Jens Grønbech; Hovmøller, Mogens Støvring

    . arrhenatheri and P. striiformoides on barberry species. Survey and DNA sample maps with species designation were displayed in the Wheat Rust ToolBox. The future aim is to integrate barberry rust survey data based on molecular diagnostics and infection assays from research groups world-wide in order to gain......Barberry (Berberis spp.) may serve as alternate host of several Puccinia species including Puccinia graminis and P. striiformis causing stem and yellow rust on cereals and grasses, respectively. In order to study the importance of barberry in the epidemiology of Puccinia species in the CWANA region...... a rust survey was initiated. The aim was to 1) develop a surveillance protocol 2) develop molecular diagnostic tools for identifying Puccinia spp. from aecial samples, and 3) develop a data management and display system of results as part of the Wheat Rust ToolBox (http...

  12. QTL analysis of crown rust resistance in perennial ryegrass under conditions of natural and artificial infection

    DEFF Research Database (Denmark)

    Schejbel, Britt; Jensen, Louise Friis Bach; Xing, Yongzhong;

    2007-01-01

    as well as by artificial pathogen inoculations using a detached leaf assessment. The broad sense heritability values for the field, detached leaf and combined assays were 0.42, 0.56, and 0.64, respectively, indicating a good potential for selection for crown rust resistance. A total of six QTLs were......Crown rust is an economically devastating disease of perennial ryegrass. Both artificial crown rust inoculations, with the possibility of several selection cycles in one year, as well as marker-assisted selection can be used for more efficient breeding of new resistant cultivars. The objective...... of this study was to map quantitative trait loci (QTL) for response to crown rust infection in perennial ryegrass. In order to identify relevant markers for response to crown rust infection, QTL mapping was performed on a ryegrass mapping population which was evaluated for resistance in the field for two years...

  13. 2004 SWFWMD Citrus County Lidar Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This metadata record describes the ortho & LIDAR mapping of Citrus County, FL. The mapping consists of LIDAR data collection, contour generation, and production...

  14. The aconitate hydratase family from Citrus

    Directory of Open Access Journals (Sweden)

    Cercos Manuel

    2010-10-01

    Full Text Available Abstract Background Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrate, is the first step of citric acid catabolism and a major component of the citrate utilization machinery. In this work, the citrus aconitase gene family was first characterized and a phylogenetic analysis was then carried out in order to understand the evolutionary history of this family in plants. Gene expression analyses of the citrus aconitase family were subsequently performed in several acidic and acidless genotypes to elucidate their involvement in acid homeostasis. Results Analysis of 460,000 citrus ESTs, followed by sequencing of complete cDNA clones, identified in citrus 3 transcription units coding for putatively active aconitate hydratase proteins, named as CcAco1, CcAco2 and CcAco3. A phylogenetic study carried on the Aco family in 14 plant species, shows the presence of 5 Aco subfamilies, and that the ancestor of monocot and dicot species shared at least one Aco gene. Real-time RT-PCR expression analyses of the three aconitase citrus genes were performed in pulp tissues along fruit development in acidic and acidless citrus varieties such as mandarins, oranges and lemons. While CcAco3 expression was always low, CcAco1 and CcAco2 genes were generally induced during the rapid phase of fruit growth along with the maximum in acidity and the beginning of the acid reduction. Two exceptions to this general pattern were found: 1 Clemenules mandarin failed inducing CcAco2 although acid levels were rapidly reduced; and 2 the acidless "Sucreña" orange

  15. Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

    Directory of Open Access Journals (Sweden)

    Neelam Mallick

    2016-01-01

    Full Text Available Objective: Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypolipidemic effects of C. sinensis and C. paradisi in rats receiving diet rich in cholesterol. Materials and Methods: All rats were divided into 11 groups each comprising 10 animals: Normal control group and hyperlipidemic control. C. sinensis treated three groups, C. paradisi treated three groups, C. sinensis and C. paradisi combination treated two groups, and group treated atorvastatin. All rats in the respective groups were treated orally with sterile water, juices, and standard drug for 8 weeks and lipid profile was estimated at the end of dosing. Results: Cholesterol, triglycerides (TGs, and low-density lipoprotein (LDL were decreased at all the three doses of C. sinensis and C. paradisi but rise in high-density lipoprotein (HDL was only significant at 8 ml/kg, and 0.3 ml/kg, respectively. Animals received the combination doses of C. sinensis and C. paradisi also showed a highly significant fall in cholesterol, LDL, and TGs, however HDL level was significantly elevated by SPJ-2 combination. Conclusion: Results suggest that C. sinensis and C. paradisi possess antihyperlipidemic activity due to phytochemicals and other essential nutrients, hence may serve as cardioprotective by preventing thrombosis.

  16. Evidence for Increased Aggressiveness in a Recent Widespread Strain of Puccinia striiformis f. sp. tritici Causing Stripe Rust of Wheat

    DEFF Research Database (Denmark)

    Milus, Eugene A; Kristensen, Kristian; Hovmøller, Mogens S

    2009-01-01

    Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based on vir...... that wheat rust fungi can adapt to warmer temperatures and cause severe disease in previously unfavorable environments......Stripe rust (yellow rust) of wheat, caused by Puccinia striiformis f. sp. tritici, has become more severe in eastern United States, Australia, and elsewhere since 2000. Recent research has shown that this coincided with a global spread of two closely related strains that were similar based...

  17. Tetranychus urticae-triggered responses promote genotype-dependent conspecific repellence or attractiveness in citrus.

    Science.gov (United States)

    Agut, Blas; Gamir, Jordi; Jaques, Josep A; Flors, Victor

    2015-08-01

    The citrus rootstocks sour orange and Cleopatra mandarin display differential resistance against Tetranychus urticae. Sour orange plants support reduced oviposition, growth rates and damage compared with Cleopatra mandarin plants. Jasmonic acid signalling and flavonoid accumulation have been revealed as key mechanisms for the enhanced resistance of sour orange plants. In this study, we observed that the release of T. urticae herbivore-induced plant volatiles (HIPVs) from sour orange plants has a marked repellent effect on conspecific mites associated with the production of the terpenes α-ocimene, α-farnesene, pinene and d-limonene, and the green leaf volatile 4-hydroxy-4-methyl-2-pentanone. By contrast, T. urticae HIPVs from Cleopatra mandarin plants promote conspecific mite attraction associated with an increase in (2-butoxyethoxy) ethanol, benzaldehyde and methyl salicylate levels. HIPVs released from sour orange plants following T. urticae infestation induce resistance in Cleopatra mandarin plants, thereby reducing oviposition rates and stimulating the oxylipin biosynthetic gene lipoxygenase2 (LOX2). Cleopatra HIPVs do not affect the response to T. urticae of these rootstocks. We conclude that sour orange plants promote herbivore-induced resistance in Cleopatra mandarin plants and, despite the weak basal resistance of these rootstocks, herbivore resistance can be induced through the combination of HIPVs, such as α-ocimene and d-limonene.

  18. 78 FR 41259 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus

    Science.gov (United States)

    2013-07-10

    ... that this argument is invalid due to the year-round marketing of citrus harvested domestically. We made... variety. Total citrus production in Uruguay in 2011 was 270,367 metric tons, which is less than 3 percent... metric tons, respectively, which is less than 3.2 percent of U.S. production and 1 percent of total...

  19. H NMR analyses of Citrus macrophylla subjected to Asian citrus psyllid (Diaphorina citri Kuwayama) feeding

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is a phloem feeding insect that can host and transmit the bacterium Candidatus Liberibacter asiaticus (CLas), which is the putative causative agent of the economically important citrus disease, Huanglongbing (HLB). ACP are widespread in Florida, and are spreading in Ca...

  20. Apparent tolerance to huanglongbing in citrus and citrus-related germplasm

    Science.gov (United States)

    In a Ft. Pierce, Florida field planting, growth and huanglongbing (HLB) severity were assessed as indicators of HLB-tolerance on progenies of 83 seed-source accessions of citrus and citrus-relatives from the Riverside, California genebank. The HLB-pathogen (Candidatus Liberibacter asiaticus) and vec...

  1. Detection of non-typhoid Salmonella infection by citrus and citrus extracts in Lao PDR

    Institute of Scientific and Technical Information of China (English)

    Yutaka Midorikawa; Satoshi Nakamura; Rattanaphone Phetsouvanh; Manivanh Vongsouvaht; Kaoru Midorikawa

    2010-01-01

    Objective: To know the current state of non-typhoid Salmonella infection in Laos. To examine the usefulness of new screening methods for Salmonella using citrus. Methods: Non-typhoidSalmonella infection of person in Lao PDR was studied in this research (2004-2009). The site was Vientiane capital city in 2004. Research from rural villages locating suburb of Vientiane during 2005-2008 was carried out. Rural villages in Attapu province where ethnic minorities were living was searched for this study in 2009. During this research, to detect Salmonella strain, a new method using citrus and citrus extract named MY phenomenon that observing black ring (MIDO ring) on DHL agar was tried. The slice lemon and lime were used for this trial in 2004. After 2005, disk of ascorbic acid and citric acid were used for the device instead of citrus fruits itself. Results: During this research, 65 of 272 human samples (23.9%) were infected with non-typhoid Salmonella. Conclusions: During this study, the method using citrus and citrus extracts was accepted for the detection of Salmonella. This study shows that with citrus and citrus extract, detection of Salmonella is possible using only DHL media. Results suggest that infectious rate of non-typhoid Salmonella was high.

  2. Phyllosticta citriasiana sp. nov., the cause of Citrus tan spot of Citrus maxima in Asia

    NARCIS (Netherlands)

    Wulandari, N.F.; To-anun, C.; Hyde, K.D.; Duong, L.M.; Gruyter, de J.; Meffert, J.P.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    Guignardia citricarpa, the causal agent of Citrus Black Spot, is subject to phytosanitary legislation in the European Union and the U.S.A. This species is frequently confused with G. mangiferae, which is a non-pathogenic, and is commonly isolated as an endophyte from citrus fruits and a wide range o

  3. Phyllosticta citriasiana sp nov., the cause of Citrus tan spot of Citrus maxima in Asia

    NARCIS (Netherlands)

    Wulandari, N.F.; To-anun, C.; Hyde, K.D.; Duong, L.M.; de Gruyter, J.; Meffert, J.P.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    Guignardia citricarpa, the causal agent of Citrus Black Spot, is subject to phytosanitary legislation in the European Union and the U.S.A. This species is frequently confused with G. mangiferae, which is a non-pathogenic, and is commonly isolated as an endophyte from citrus fruits and a wide range o

  4. Assessing Wheat Yellow Rust Disease through Hyperspectral Remote Sensing

    Science.gov (United States)

    Krishna, G.; Sahoo, R. N.; Pargal, S.; Gupta, V. K.; Sinha, P.; Bhagat, S.; Saharan, M. S.; Singh, R.; Chattopadhyay, C.

    2014-12-01

    The potential of hyperspectral reflectance data was explored to assess severity of yellow rust disease (Biotroph Pucciniastriiformis) of winter wheat in the present study. The hyperspectral remote sensing data was collected for winter wheat (Triticum aestivum L.) cropat different levels of disease infestation using field spectroradiometer over the spectral range of 350 to 2500 nm. The partial least squares (PLS) and multiple linear (MLR) regression techniques were used to identify suitable bands and develop spectral models for assessing severity of yellow rust disease in winter wheat crop. The PLS model based on the full spectral range and n = 36, yielded a coefficient of determination (R2) of 0.96, a standard error of cross validation (SECV) of 12.74 and a root mean square error of cross validation (RMSECV) of 12.41. The validation analysis of this PLS model yielded r2 as 0.93 with a SEP (Standard Error of Prediction) of 7.80 and a RMSEP (Root Mean Square Error of prediction) of 7.46. The loading weights of latent variables from PLS model were used to identify sensitive wavelengths. To assess their suitability multiple linear regression (MLR) model was applied on these wavelengths which resulted in a MLR model with three identified wavelength bands (428 nm, 672 nm and 1399 nm). MLR model yielded acceptable results in the form of r2 as 0.89 for calibration and 0.90 for validation with SEP of 3.90 and RMSEP of 3.70. The result showed that the developed model had a great potential for precise delineation and detection of yellow rust disease in winter wheat crop.

  5. Screening and incorporation of rust resistance from Allium cepa into bunching onion (Allium fistulosum) via alien chromosome addition.

    Science.gov (United States)

    Wako, Tadayuki; Yamashita, Ken-ichiro; Tsukazaki, Hikaru; Ohara, Takayoshi; Kojima, Akio; Yaguchi, Shigenori; Shimazaki, Satoshi; Midorikawa, Naoko; Sakai, Takako; Yamauchi, Naoki; Shigyo, Masayoshi

    2015-04-01

    Bunching onion (Allium fistulosum L.; 2n = 16), bulb onion (Allium cepa L. Common onion group), and shallot (Allium cepa L. Aggregatum group) cultivars were inoculated with rust fungus, Puccinia allii, isolated from bunching onion. Bulb onions and shallots are highly resistant to rust, suggesting they would serve as useful resources for breeding rust resistant bunching onions. To identify the A. cepa chromosome(s) related to rust resistance, a complete set of eight A. fistulosum - shallot monosomic alien addition lines (MAALs) were inoculated with P. allii. At the seedling stage, FF+1A showed a high level of resistance in controlled-environment experiments, suggesting that the genes related to rust resistance could be located on shallot chromosome 1A. While MAAL, multi-chromosome addition line, and hypoallotriploid adult plants did not exhibit strong resistance to rust. In contrast to the high resistance of shallot, the addition line FF+1A+5A showed reproducibly high levels of rust resistance.

  6. A house dust mite allergen homologue from poultry red mite Dermanyssus gallinae (De Geer).

    Science.gov (United States)

    Nisbet, A J; Huntley, J F; Mackellar, A; Sparks, N; McDevitt, R

    2006-08-01

    Tropomyosin is an allergenic, actin-binding protein and a proposed vaccine candidate from several species of parasite. Tropomyosin cDNA, obtained by polymerase chain reaction (PCR) amplification from Dermanyssus gallinae RNA, encoded a predicted protein with 89% and 88% identity to tropomyosins from the ticks Boophilus microplus and Haemaphysalis longicornis, respectively, and 85% identity to the house dust mite (HDM) tropomyosin Der p 10. Mouse antibodies raised against HDM tropomyosin reacted with a band of 38 kDa on Western blots of D. gallinae extract, consistent with the molecular masses of acarine tropomyosins and the putative product of the cDNA encoding D. gallinae tropomyosin. When the same preparation of D. gallinae proteins was used in Western blots with serum from infested hens, the IgY component of the serum bound to a number of mite proteins, but not to tropomyosin, indicating that hens are not directly exposed to this allergen during a natural infestation. Immunolocalization of tropomyosin in mites indicated a ubiquitous distribution of the molecule in mite tissues. Immunolocalization and Western blotting also indicated that poultry red mites ingest host IgY.

  7. Salivary proteins of spider mites suppress defenses in Nicotiana benthamiana and promote mite reproduction.

    Science.gov (United States)

    Villarroel, Carlos A; Jonckheere, Wim; Alba, Juan M; Glas, Joris J; Dermauw, Wannes; Haring, Michel A; Van Leeuwen, Thomas; Schuurink, Robert C; Kant, Merijn R

    2016-04-01

    Spider mites (Tetranychidae sp.) are widely occurring arthropod pests on cultivated plants. Feeding by the two-spotted spider mite T. urticae, a generalist herbivore, induces a defense response in plants that mainly depends on the phytohormones jasmonic acid and salicylic acid (SA). On tomato (Solanum lycopersicum), however, certain genotypes of T. urticae and the specialist species T. evansi were found to suppress these defenses. This phenomenon occurs downstream of phytohormone accumulation via an unknown mechanism. We investigated if spider mites possess effector-like proteins in their saliva that can account for this defense suppression. First we performed an in silico prediction of the T. urticae and the T. evansi secretomes, and subsequently generated a short list of candidate effectors based on additional selection criteria such as life stage-specific expression and salivary gland expression via whole mount in situ hybridization. We picked the top five most promising protein families and then expressed representatives in Nicotiana benthamiana using Agrobacterium tumefaciens transient expression assays to assess their effect on plant defenses. Four proteins from two families suppressed defenses downstream of the phytohormone SA. Furthermore, T. urticae performance on N. benthamiana improved in response to transient expression of three of these proteins and this improvement was similar to that of mites feeding on the tomato SA accumulation mutant nahG. Our results suggest that both generalist and specialist plant-eating mite species are sensitive to SA defenses but secrete proteins via their saliva to reduce the negative effects of these defenses.

  8. Intestinal proteases of free-living and parasitic astigmatid mites.

    Science.gov (United States)

    Holt, Deborah C; Burgess, Stewart T G; Reynolds, Simone L; Mahmood, Wajahat; Fischer, Katja

    2013-02-01

    Among arthropod pests, mites are responsible for considerable damage to crops, humans and other animals. However, detailed physiological data on these organisms remain sparse, mainly because of their small size but possibly also because of their extreme diversity. Focusing on intestinal proteases, we draw together information from three distinct mite species that all feed on skin but have separately adapted to a free-living, a strictly ecto-parasitic and a parasitic lifestyle. A wide range of studies involving immunohistology, molecular biology, X-ray crystallography and enzyme biochemistry of mite gut proteases suggests that these creatures have diverged considerably as house dust mites, sheep scab mites and scabies mites. Each species has evolved a particular variation of a presumably ancestral repertoire of digestive enzymes that have become specifically adapted to their individual environmental requirements.

  9. Músicas al límite

    OpenAIRE

    2007-01-01

    Los límite de la música dependen de su propia definición y de su carácter humano. El empleo de sonido animal ha sido una constante a lo largo del tiempo y es una variante del empleo o miméis de sonidos naturales. La ampliación de los sonidos musicales hacia el ruido es otro de los límites desbordados ya sea ruidoo natural ,que nos lleva a la concepción moderna del paisaje sonoro o artificial que va desde los distintos bruitismos al sonido electrónico. También la naturaleza matemát...

  10. Oribatid mites in a changing world

    OpenAIRE

    2011-01-01

    The main scope of this thesis is to illustrate the validity of oribatid mites as tools for palaeoecological reconstructions. Palaeoecology studies the responses of past organisms to past environmental changes. This can be accomplished through the use of biological proxies, which are indicators of past conditions. The search for additional means of distinguishing climate change has only recently led to the use of other commonly found biological proxies such ...

  11. Predatory mite fauna in Aegean vineyards

    OpenAIRE

    GÖVEN, Mehmet Ali; ÇOBANOĞLU, Sultan; GÜVEN, Bilgin

    2010-01-01

    This study was carried out between 1997-2004 in vineyard areas in Manisa, İzmir, Denizli, Muğla and Çanakkale (Bozcaada) provinces of the Aegean region to determine biological control possibilities against phytophagous mites. Sampling was conducted from May to October. Most of the vineyards were sampled three times during the growing season and 50 leaves were collected randomly in each vineyard. Colomerus vitis (Pagenstecher) and Calepitrimerus vitis (Nalepa)were determined ...

  12. Mathematical modeling of citrus groves infected by huanglongbing.

    Science.gov (United States)

    Jacobsen, Karly; Stupiansky, Jillian; Pilyugin, Sergei S

    2013-06-01

    Huanglongbing (citrus greening) is a bacterial disease that is significantly impacting the citrus industry in Florida and poses a risk to the remaining citrus-producing regions of the United States. A mathematical model of a grove infected by citrus greening is developed. An equilibrium stability analysis is presented. The basic reproductive number and its relation to the persistence of the disease is discussed. A numerical study is performed to illustrate the theoretical findings.

  13. Health effects of predatory beneficial mites and wasps in greenhouses

    DEFF Research Database (Denmark)

    Bælum, Jesper; Enkegaard, Annie; Doekes, Gert

    2007-01-01

    A three-year study of 579 greenhouse workers in 31 firms investigated the effect of four different beneficial arthropods. It was shown that the thrips mite Amblyseeius cucumeris and the spider mite predator Phytoseiulus persimilis may cause allergy measured by blood tests as well as eye and nose...... symptoms. No effect was seen by the predator wasp Aphidius colemani nor the predator mite Hypoaspis miles and no effect on lung diseases were seen....

  14. Health effects of predatory beneficial mites and wasps in greenhouses

    DEFF Research Database (Denmark)

    Bælum, Jesper; Enkegaard, Annie; Doekes, Gert;

    A three-year study of 579 greenhouse workers in 31 firms investigated the effect of four different beneficial arthropods. It was shown that the thrips mite Amblyseeius cucumeris and the spider mite predator Phytoseiulus persimilis may cause allergy measured by blood tests as well as eye and nose...... symptoms. No effect was seen by the predator wasp Aphidius colemani nor the predator mite Hypoaspis miles and no effect on lung diseases were seen....

  15. Evidence for horizontal transfer of Wolbachia by a Drosophila mite.

    Science.gov (United States)

    Brown, Amy N; Lloyd, Vett K

    2015-07-01

    Mites are common ectoparasites of Drosophila and have been implicated in bacterial and mobile element invasion of Drosophila stocks. The obligate endobacterium, Wolbachia, has widespread effects on gene expression in their arthropod hosts and alters host reproduction to enhance its survival and propagation, often with deleterious effects in Drosophila hosts. To determine whether Wolbachia could be transferred between Drosophila melanogaster laboratory stocks by the mite Tyrophagus putrescentiae, mites were introduced to Wolbachia-infected Drosophila vials. These vials were kept adjacent to mite-free and Wolbachia-uninfected Drosophila stock vials. The Wolbachia infection statuses of the infected and uninfected flies were checked from generation 1 to 5. Results indicate that Wolbachia DNA could be amplified from mites infesting Wolbachia-infected fly stocks and infection in the previously uninfected stocks arose within generation 1 or 2, concomitant with invasion of mites from the Wolbachia-infected stock. A possible mechanism for the transfer of Wolbachia from flies to mites and vice versa, can be inferred from time-lapse photography of fly and mite interactions. We demonstrated that mites ingest Drosophila corpses, including Wolbachia-infected corpses, and Drosophila larva ingest mites, providing possible sources of Wolbachia infection and transfer. This research demonstrated that T. putrescentiae white mites can facilitate Wolbachia transfer between Drosophila stocks and that this may occur by ingestion of infected corpses. Mite-vectored Wolbachia transfer allows for rapid establishment of Wolbachia infection within a new population. This mode of Wolbachia introduction may be relevant in nature as well as in the laboratory, and could have a variety of biological consequences.

  16. The role of green rust in the environment: a review O papel do green rust no ambiente

    Directory of Open Access Journals (Sweden)

    Lucia H. G. Chaves

    2005-06-01

    Full Text Available Iron(II-iron(III hydroxy-salts known as green rusts (GRs initially were identified and studied as corrosion products of steel and iron. Recently they were discovered as minerals present in hydromorphic soils and sediments. Different studies have suggested that GRs, due to their high reactivity, play an important role in the fate and transport of many contaminants in suboxic soils, sediments and aquifers where microbial reduction rates are limited by low carbon content. Also, GRs have considerable potential for applications such as water-purification processes and gas adsorbents. However, as GRs are only a transient state during the reduction of ferric iron and are converted to more stable forms, it is still necessary to continue studies about their behavior.Hidróxidos de ferro (II-ferro(III conhecidos como "green rust" (GR, inicialmente foram identificados e estudados como sendo os produtos provenientes da corrosão do aço e do ferro. Recentemente esses hidróxidos foram encontrados na forma mineral em solos hidromórficos e em sedimentos. Devido a sua alta reatividade, muitos trabalhos têm mostrado que esses hidróxidos desempenham um importante papel no destino e transporte de muitos contaminantes em solos subóxicos, sedimentos e aqüíferos, onde a taxa de redução microbiana é limitada pelo baixo conteúdo de carbono. Os "green rusts" também podem ser utilizados nos processos de purificação de águas e como adsorventes de gases. Entretanto, como GR são considerados uma fase transitória durante a redução do íon férrico e são, rapidamente, convertidos para formas mais estáveis, é necessário que os estudos sobre seu comportamento continuem.

  17. Relationship between the ability to penetrate complex webs of Tetranychus spider mites and the ability of thread-cutting behavior in phytoseiid predatory mites

    NARCIS (Netherlands)

    Shimoda, T.; Kishimoto, H.; Takabayashi, J.; Amano, H.; Dicke, M.

    2010-01-01

    Predatory mites, that are important natural enemies of Tetranychus spider mites, are less hindered by complex webs of the spider mites than are other predatory mites that are natural enemies of other pest herbivores. This can be partly explained by their chaetotaxy, a morphological protection agains

  18. Introgression of a leaf rust resistance gene from Aegilops caudata to bread wheat

    Indian Academy of Sciences (India)

    Amandeep Kaur Riar; Satinder Kaur; H. S. Dhaliwal; Kuldeep Singh; Parveen Chhuneja

    2012-08-01

    Rusts are the most important biotic constraints limiting wheat productivity worldwide. Deployment of cultivars with broad spectrum rust resistance is the only environmentally viable option to combat these diseases. Identification and introgression of novel sources of resistance is a continuous process to combat the ever evolving pathogens. The germplasm of nonprogenitor Aegilops species with substantial amount of variability has been exploited to a limited extent. In the present investigation introgression, inheritance and molecular mapping of a leaf rust resistance gene of Ae. caudata (CC) acc. pau3556 in cultivated wheat were undertaken. An F2 population derived from the cross of Triticum aestivum cv.WL711 – Ae. caudata introgression line T291-2 with wheat cultivar PBW343 segregated for a single dominant leaf rust resistance gene at the seedling and adult plant stages. Progeny testing in F3 confirmed the introgression of a single gene for leaf rust resistance. Bulked segregant analysis using polymorphic D-genome-specific SSR markers and the cosegregation of the 5DS anchored markers (Xcfd18, Xcfd78, Xfd81 and Xcfd189) with the rust resistance in the F2 population mapped the leaf rust resistance gene (LrAC) on the short arm of wheat chromosome 5D. Genetic complementation and the linked molecular markers revealed that LrAC is a novel homoeoallele of an orthologue Lr57 already introgressed from the 5M chromosome of Ae. geniculata on 5DS of wheat.

  19. A reassessment of the risk of rust fungi developing resistance to fungicides.

    Science.gov (United States)

    Oliver, Richard P

    2014-11-01

    Rust fungi are major pathogens of many annual and perennial crops. Crop protection is largely based on genetic and chemical control. Fungicide resistance is a significant issue that has affected many crop pathogens. Some pathogens have rapidly developed resistance and hence are regarded as high-risk species. Rust fungi have been classified as being low risk, in spite of sharing many relevant features with high-risk pathogens. An examination of the evidence suggests that rust fungi may be wrongly classified as low risk. Of the nine classes of fungicide to which resistance has developed, six are inactive against rusts. The three remaining classes are quinone outside inhibitors (QoIs), demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs). QoIs have been protected by a recently discovered intron that renders resistant mutants unviable. Low levels of resistance have developed to DMIs, but with limited field significance. Older SDHI fungicides were inactive against rusts. Some of the SDHIs introduced since 2003 are active against rusts, so it may be that insufficient time has elapsed for resistance to develop, especially as SDHIs are generally sold in mixtures with other actives. It would therefore seem prudent to increase the level of vigilance for possible cases of resistance to established and new fungicides in rusts.

  20. First report of citrus leprosis virus nuclear type in Colombia

    Science.gov (United States)

    Citrus leprosis is a difficult viral disease causing significant damage to citrus fruit in South America and Central America. The disease is marked by dramatic lesions on fruit, leaves and stems resulting in unmarketable product. Citrus leprosis virus cytoplasmic types (CiLV-C and CiLV-C2) wer edete...

  1. Trailers transporting oranges to processing plants move Asian citrus psyllids

    Science.gov (United States)

    Huanglongbing (citrus greening) is one of the most serious of citrus diseases. Movement of the disease occurs as a result of natural vector-borne infection and by movement of plant material. We demonstrate here that Diaphorina citri Kuwayama (vector of citrus greening pathogens) can be transported i...

  2. Wavelength and polarization affect phototaxis of the Asian citrus psyllid

    Science.gov (United States)

    The Asian citrus psyllid, D. citri, is a primary pest for citrus production due to its status as a vector of the citrus disease, huanglongbing. We investigated phototactic behavior of D. citri to evaluate effects of light of specific wavelength or polarization using a horizontal bioassay arena. Wave...

  3. Current California Drought: Impact on Citrus Trees and Potential Mitigation

    Science.gov (United States)

    California is in another cycle of extended drought. The article reviews and discusses likely impact of the current drought on citrus growers and potential mitigation techniques. Citrus physiological responses to water stress is briefly reviewed. The direct impact of drought on citrus is reduced frui...

  4. Biological Indexing of Graft Transmissible Diseases of Citrus

    Science.gov (United States)

    Biological indexing for the detection of graft transmissible diseases of citrus is essential for maintaining a citrus certification program. Many of the graft transmissible diseases of citrus are harbored as latent infections in the scions, but when propagated on a susceptible rootstock that allow...

  5. Genome wide selection in Citrus breeding.

    Science.gov (United States)

    Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

    2016-10-17

    Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq(TM) (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

  6. House dust mite control measures for asthma: systematic review

    DEFF Research Database (Denmark)

    Gøtzsche, Peter C.; Johansen, Helle Krogh

    2008-01-01

    The major allergen in house dust comes from mites. We performed a systematic review of the randomized trials that had assessed the effects of reducing exposure to house dust mite antigens in the homes of people with mite-sensitive asthma, and had compared active interventions with placebo...... improved (relative risk 1.01, 95% CI 0.80-1.27), asthma symptom scores (standardized mean difference -0.04, 95% CI -0.15 to 0.07) or in medication usage (standardized mean difference -0.06, 95% CI -0.18 to 0.07). Chemical and physical methods aimed at reducing exposure to house dust mite allergens cannot...

  7. HOUSE DUST MITE ALLERGY IN VIEW OF MOLECULAR ALLERGOLOGY

    Directory of Open Access Journals (Sweden)

    E. S. Korovkina

    2012-01-01

    Full Text Available Abstract. Incidence of allergic diseases is increased over last years. House dust is considered a major risk factor of allergic sensitization which plays an important role in development of allergic rhinitis, bronchial asthma, atopic dermatitis. Dust mites in the home comprise a large part of domestic allergens. Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, Lepidoglyphus destructor, Blomia tropicalis are most important in this respect. Der p 1 and Der p 2 are regarded as major house dust mite allergens. Recent studies concerned induction of IgE responses against mite tropomyosin (Der p 10, an allergen occurring in mites which exhibits high cross-reactivity with tropomyosins from a variety of sea foods (e.g. shrimps, as well as human tropomyosins. Allergen-specific immunotherapy (ASIT represents the only causative approach to allergy treatment in such cases. From this viewpoint, a quantitation of specific IgЕ against major house dust mite allergens would be necessary to predict ASIT efficiency. Treatment by house dust mites allergen extracts is effective in management of allergic rhinitis and mild asthma. A component-resolved diagnostic (CRD with purified house-dust mites allergens allows to discriminate patients who were mostly sensitized to the major house dust mites allergens (e.g. Der p 10, tropomyosin. The component-resolved diagnostics could be performed before starting the allergen-specific immunotherapy by mite allergens, in order to avoid unresponsiveness to this mode of therapy.

  8. Mites associated with stored grain commodities in Benin, West Africa.

    Science.gov (United States)

    Zannou, Ignace D; Adebo, Habib O; Zannou, Elisabeth; Hell, Kerstin

    2013-12-01

    After insects, mites are the major arthropod pests that inhabit stored agricultural products worldwide. To determine the acarofauna that infests cowpea, maize, paddy rice and sorghum in Benin (West Africa), surveys were conducted in some principal markets (Dantokpa, Glazoue and Parakou) of this country. A total of 555 samples of grains and debris were collected in May and September 2011. More than 56 species belonging to 24 mite families were recorded in the four products. These mite species included predators, parasites, fungivorous, phytophagous and other groups whose feeding habits are not well known. The family Cheyletidae was the most prevalent and the most diverse predatory mite family encountered, in which Cheyletus malaccensis Oudemans was the most abundant species. Several families of mite pests and mites responsible for allergies (Acaridae, Glycyphagidae, Pyroglyphidae, Pyemotidae and Saproglyphidae) were also detected. The three most dominant and frequent species were C. malaccensis, Suidasia nesbitti (Hughes) and Suidasia sp. Statistical analysis showed that densities of these three mite species were higher in Parakou than in Glazoue and Dantokpa, on one hand, and higher in debris than in grains, on the other hand. The densities of S. nesbitti and Suidasia sp. decreased significantly during the dry season, whereas C. malaccensis remained stable throughout the two samplings. Of all grains, sorghum was the least infested with mites. This study shows that in Benin mites are present in stored agricultural products to which they cause serious damage, and may cause various allergies to people.

  9. Detailed sterol compositions of two pathogenic rust fungi.

    Science.gov (United States)

    Giner, José-Luis; Zhao, Hui

    2004-08-01

    Teliospores of cedar-apple rust Gymnosporangium juniperi-virginianae were collected from the eastern red cedar Juniperus virginiana, and aeciospores of quince rust G. clavipes were collected from the fruit of English hawthorn Crataegus laevigata. The sterol fractions were separated by HPLC, and their identities were determined by 600 MHz 1H NMR. Twenty-six sterols were isolated from G. juniperi-virginianae and 18 sterols were isolated from G. clavipes. The principal sterol of both fungi was (Z)-stigmasta-7,24(28)-dien-3beta-ol. Other major sterols were (24S)-ergost-7-en-3beta-ol, (24S)-stigmast-7-en-3beta-ol, and (24S)-stigmasta-5,7-dien-3beta-ol. The sterols of the hosts were found to be very different from those of the fungi. The 24-alkyl sterols of the fungi had the 24alpha-configuration, whereas those of the hosts had the 24beta-configuration. Similarities to the sterol composition of the AIDS pneumonia fungus Pneumocystis carinii are discussed.

  10. Reliability of the radiographic union scale in tibial fractures (RUST

    Directory of Open Access Journals (Sweden)

    Fernando Antonio Silva de Azevedo Filho

    Full Text Available ABSTRACT OBJECTIVE: This study aimed to evaluate the inter- and intra observer reproducibility of the radiographic score of consolidation of the tibia shaft fractures. METHODS: Fifty-one sets of radiographs in anteroposterior (AP and profile (P of the tibial shaft treated with intramedullary nail were obtained. The analysis of X-rays was performed in two stages, with a 21-day interval between assessments by a group of nine evaluators. To evaluate the reproducibility of RUST score between the evaluators, the intra-class correlation coefficient (ICC with a 95% confidence interval was used. ICC values range from +1, representing perfect agreement, to -1, complete disagreement. RESULTS: There was a significant correlation among all evaluators: ICC = 0.87 (95% CI 0.81 to 0.91. The intraobserver agreement proved to be substantial with ICC = 0.88 (95% CI 0.85 to 0.91 . CONCLUSION: This study confirms that the RUST scale shows a high degree of reliability and agreement.

  11. Evidence refuting the contribution of the fungus Aspergillus penicillioides to the allergenicity of the house dust mite Dermatophagoides pteronyssinus.

    Science.gov (United States)

    Hay, D B; Hart, B J; Douglas, A E

    1992-01-01

    This communication demonstrates unequivocally that the fungi associated with house dust mites do not contribute to mite allergenicity. The evidence is twofold: first, larval mites which lack fungi have allergen profiles indistinguishable from fungus-bearing adult mites. Second, the allergen profile of experimentally-derived fungus-free adult mites and mites re-fed the fungus Aspergillus penicillioides are identical.

  12. Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

    Science.gov (United States)

    Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

  13. Overexpression of a modified plant thionin enhances disease resistance to citrus canker and huanglongbing (HLB, citrus greening)

    Science.gov (United States)

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized e...

  14. IDENTIFICATION AND QUANTIFICATION OF DIFFERENTIALLY EXPRESSED GENES ASSOCIATED WITH CITRUS BLIGHT (Citrus spp.

    Directory of Open Access Journals (Sweden)

    José Renato de Abreu

    2015-02-01

    Full Text Available Brazil is the largest citrus producer in the world, being responsible for more than 20% of its production, which is, however still low due to phytosanitary issues such as citrus blight. Citrus blight is an anomaly whose causes still have not yet been determined, therefore there are no efficient control measures to minimize the production losses with the use of resistant varieties being considered the most appropriate method. However, little is known about the genes involved in the defense response of the plants to this anomaly. Considering that many physiological alterations associated with plant stress responses are controlled at a transcriptional level, in this study we sought the identification and characterization of the gene expression products differentially expressed in the response to the citrus blight. Through the suppressive subtractive hybridization technique, expressed cDNA libraries were built using mRNAs isolated from "Cravo" lemon tree roots (Citrus limonia L. Osbeck under "Pera" orange (Citrus sinensis L. Osbeck of healthy and sick plants. 129 clones were obtained by subtraction and their sequences were compared in databases. 34 of them linked to proteins associated to stress processes, while the others were similar to sequences of unknown functions or did not present similarity with sequences deposited in the databases. 3 genes were selected and their expressions were studied by RT - qPCR in real-time. Plants with citrus blight presented an increase of the expression level in two of those genes, suggesting that these can be directly involved with this anomaly.

  15. Tyrophagus putrescentiae mites grown in dog food cultures and the effect mould growth has on mite survival and reproduction.

    Science.gov (United States)

    Canfield, Michael S; Wrenn, William J

    2010-02-01

    The purposes of this study were to determine whether the storage mite, Tyrophagus putrescentiae, could survive and thrive on dog food and if mould growth was important to their survival. All of the chambers (n = 42) were started with 10 female mites and evaluated every other day for mite survival and for the spontaneous development of mould. Ten chambers tested the effect of low moisture on mite survival. Eight chambers were used as positive and negative controls (n = 4 each); positive control mites were fed Fleischmann's((R)) yeast and negative controls had no food source. Three dog foods were evaluated in the same manner. Four chambers had food but mould development was limited by replacing the food kernel every 48 h and four chambers were allowed to grow mould. Mites grown in chambers without moisture died from desiccation within 5 days. The termination point was day 34 when all mites in the negative control group (moisture but no food) died. Although T. putrescentiae survived and grew on all three commercial dog foods, there was no statistically significant difference in mites counts among the dog foods (P dog food. The study demonstrated that the presence of mould positively influences mite viability, while low relative humidity can result in detrimental consequences for T. putrescentiae.

  16. Titers of 'Ca. Liberibacter asiaticus' in Murraya paniculata and Murraya-reared Diaphorina citri Are Much Lower than in Citrus and Citrus-reared Psyllids

    National Research Council Canada - National Science Library

    Walter, Abigail; Duan, Y; Hall, David G

    2012-01-01

    Huanglongbing, one of the most devastating diseases of citrus, is associated with the bacterium 'Candidatus Liberibacter asiaticus' vectored by the Asian citrus psyllid, Diaphorina citri, in North America...

  17. Occupational exposure to allergenic mites in a Polish zoo.

    Science.gov (United States)

    Solarz, Krzysztof; Szilman, Piotr; Szilman, Ewa

    2004-01-01

    The study was carried out from April 2000-March 2001. During this period 49 samples of dust, litter, debris and residues from cages and run-offs of mammals, birds and reptiles in the Silesian Zoo, were examined for the presence of mites, especially the allergenic taxa. Mites were extracted using the Berlese method and preserved in 70 % ethanol. For identification, the mites were mounted in Hoyer's medium on microscope slides. Mites were found in 44 of 49 samples analyzed (89.8 %). A total of 5,097 mites were collected, from which 60.3 % were found in samples collected in spring, whereas only 13 % in summer and 24.1 % in autumn. The remaining 2.6 % of the total mite population was found in winter. Majority of mites (82.7 %) were collected from aviaries of macaws and cockatiels (Ara ararauna and Nymphicus hollandicus). A total of 10 species of astigmatid mites were identified that belong to 4 families--Acaridae, Glycyphagidae, Anoetidae and Pyroglyphidae. Generally, the allergenic mites of the order Astigmata constituted 49.5 % of the total count. Among them Acarus farris was predominant (34 % of the total count), followed by Tyrophagus putrescentiae (4.7 %), Caloglyphus sp. (4.35 %) and Acarus immobilis (4.31 %). Dermatophagoides farinae, the house-dust-mite species, was for the first time found in this environment. D. farinae (0.05 % of the total population) was associated with parrots, canids and artiodactyls. Summarizing, it should be stressed, that cages and run-offs of different mammals, aviaries of parrots and terrariums of snakes are important sources of some allergenic mites, especially A. farris and T. putrescentiae, that might cause allergies in workers.

  18. Infection of Psoroptes mites with the fungus Metarhizium anisopliae.

    Science.gov (United States)

    Brooks, A J; Wall, R

    2001-01-01

    The astigmatid mite, Psoroptes ovis (Hering) (Acari: Psoroptidae), is an obligatory ectoparasite that causes psoroptic mange in a range of domesticated animals, particularly sheep, where the clinical disease is known as sheep scab. A series of laboratory assays were used to assess the use of the fungus, Metarhizium anisopliae (Metchnikoff) (Deuteromycotina: Hyphomycetes) as a biocontrol agent for P. ovis derived from rabbits (syn. P. cuniculi). The immersion of mites in a suspension of conidia of M. anisopliae resulted in the acquisition of fatal infections. The number of mites which developed infections increased significantly with the increasing concentration of the conidial suspension to which they were exposed; 77% of mites developed infections when exposed to the highest concentration used (1 x 10(8) conidia ml(-1)). Controls developed no fungal infections. Mites allowed simply to walk across a surface which had been treated with a suspension of conidia also acquired fungal infections; the number infected was again related to the concentration of conidia present. After contact for 24 h with a surface treated with 1 x 10(8) conidia ml(-1), 73% of the mites became infected. To determine whether dead infected mites could act as sources of infection, infected cadavers were placed in chambers with live uninfected mites. The uninfected mites acquired fatal infections from the cadavers; a higher ratio of infected cadavers to uninfected mites resulted in greater transmission of infection. The time after death of the infected cadaver was also an important factor influencing the number infected, 5-day-old cadavers were the most infective and 18-day-old cadavers the least infective. The results indicate that M. anisopliae is a good candidate control agent for Psoroptes mites.

  19. Detection of citrus canker and Huanglongbing using fluorescence imaging spectroscopy and support vector machine technique.

    Science.gov (United States)

    Wetterich, Caio Bruno; Felipe de Oliveira Neves, Ruan; Belasque, José; Marcassa, Luis Gustavo

    2016-01-10

    Citrus canker and Huanglongbing (HLB) are citrus diseases that represent a serious threat to the citrus production worldwide and may cause large economic losses. In this work, we combined fluorescence imaging spectroscopy (FIS) and a machine learning technique to discriminate between these diseases and other ordinary citrus conditions that may be present at citrus orchards, such as citrus scab and zinc deficiency. Our classification results are highly accurate when discriminating citrus canker from citrus scab (97.8%), and HLB from zinc deficiency (95%). These results show that it is possible to accurately identify citrus diseases that present similar symptoms.

  20. Size of predatory mites and refuge entrance determine success of biological control of the coconut mite

    NARCIS (Netherlands)

    da Silva, F.R.; de Moraes, G.J.; Lesna, I.; Sato, Y.; Vasquez, C.; Hanna, R.; Sabelis, M.W.; Janssen, A.

    2016-01-01

    Predators face the challenge of accessing prey that live in sheltered habitats. The coconut mite Aceriaguerreronis Keifer (Acari: Eriophyidae) lives hidden beneath the perianth, which is appressed to the coconut fruit surface, where they feed on the meristematic tissue. Its natural enemy, the predat

  1. Allergy to mites : relation to lung function and airway hyperresponsiveness

    NARCIS (Netherlands)

    van der Heide, S; Dubois, AEJ; Kauffman, HF; de Monchy, JGR

    1998-01-01

    Exposure to house-dust-mite allergens is an important cause of allergic reactions in sensitized patients. In community-based studies, sensitization to house-duct mites, as ascertained by a positive skin test or by an increased allergen-specific IgE level in serum, is associated with both diminished

  2. Checklist of the Oribatid Mites of the Netherlands (Acari: Oribatida)

    NARCIS (Netherlands)

    Siepel, H.; Zaitsev, A.; Berg, M.

    2009-01-01

    More than fifty years ago Van der Hammen published the last checklist of oribatid mites (or moss mites) for the Netherlands. Since then the species number has almost doubled to 318 species, of which 100 are presented here for the first time. Brief data on occurence and nomenclature are provided for

  3. Ecology, life history and management of tropilaelaps mites

    Science.gov (United States)

    Parasitic mites are the major threat of the Western honey bee, Apis mellifera. For much of the world, Varroa destructor single-handedly inflicts unsurmountable problems to A. mellifera beekeeping. However, A. mellifera in Asia is also faced with another genus of destructive parasitic mite, Tropilae...

  4. Invasion of Varroa mites into honey bee brood cells.

    NARCIS (Netherlands)

    Boot, W.J.

    1995-01-01

    The parasitic mite Varroa-jacobsoni is one of the most serious pests of Western honey bees, Apis mellifera. The mites parasitize adult bees, but reproduction only occurs while parasitizing on honey bee brood. Invasion into a drone or a worker cell is therefore a crucial step in the life of Varroa m

  5. Induction of atopic dermatitis by inhalation of house dust mite

    NARCIS (Netherlands)

    Tupker, RA; DeMonchy, JGR; Coenraads, PJ; vanderMeer, JB

    Background: The pathogenetic role of house dust mite in atopic dermatitis remains controversial. Recent studies have shown that intensive epicutaneous contact of house dust mite allergen with premanipulated skin may induce dematitis. It is, however, uncertain whether such conditions are met during

  6. IPM potentials of microbial pathogens and diseases of mites

    NARCIS (Netherlands)

    van der Geest, L.P.S.; Ciancio, A.; Mukerji, K.G.

    2010-01-01

    An overview is given of diseases in mites, caused by infectious microorganisms. Many pathogens play an important role in the regulation of natural populations of mite populations and are for this reason subject of research on the feasibility to develop such pathogens to biological control agents. Se

  7. Induction of atopic dermatitis by inhalation of house dust mite

    NARCIS (Netherlands)

    Tupker, RA; DeMonchy, JGR; Coenraads, PJ; vanderMeer, JB

    1996-01-01

    Background: The pathogenetic role of house dust mite in atopic dermatitis remains controversial. Recent studies have shown that intensive epicutaneous contact of house dust mite allergen with premanipulated skin may induce dematitis. It is, however, uncertain whether such conditions are met during n

  8. Health effects of predatory beneficial mites and wasps in greenhouses

    DEFF Research Database (Denmark)

    Bælum, Jesper; Enkegaard, Annie; Doekes, Gert

    2007-01-01

    A three-year study of 579 greenhouse workers in 31 firms investigated the effect of four different beneficial arthropods. It was shown that the thrips mite Amblyseeius cucumeris and the spider mite predator Phytoseiulus persimilis may cause allergy measured by blood tests as well as eye and nose...

  9. IPM potentials of microbial pathogens and diseases of mites

    NARCIS (Netherlands)

    van der Geest, L.P.S.; Ciancio, A.; Mukerji, K.G.

    2010-01-01

    An overview is given of diseases in mites, caused by infectious microorganisms. Many pathogens play an important role in the regulation of natural populations of mite populations and are for this reason subject of research on the feasibility to develop such pathogens to biological control agents.

  10. Epidemiological study of small ruminant mange mites in three agro ...

    African Journals Online (AJOL)

    P=0.79) of the host animals not affected the prevalence of mange mite (There was higher infestation of ... Though, mange mites in small ruminants are prevalent in Southern nation nationalities .... Summery of the coordinated project on development of feed ... In: Gray, G., Vilenberg, G., parasitological research in Africa, Nai-.

  11. Genetics of adult plant stripe rust resistance in CSP44, a selection from Australian wheat

    Indian Academy of Sciences (India)

    Renu Khanna; U. K. Bansal; R. G. Saini

    2005-12-01

    Wheat line CSP44, a selection from an Australian bread wheat cultivar Condor, has shown resistance to stripe rust in India since the last twenty years. Seedlings and adult plants of CSP44 showed susceptible infection types against stripe rust race 46S119 but displayed average terminal disease severity of 2.67 on adult plants against this race as compared to 70.33 of susceptible Indian cultivar, WL711. This suggests the presence of nonhypersensitive adult plant stripe rust resistance in the line CSP44. The evaluation of F1, F2 and F3 generations and F6 SSD families from the cross of CSP44 with susceptible wheat cultivar WL711 for stripe rust severity indicated that the resistance in CSP44 is based on two genes showing additive effect. One of these two genes is Yr18 and the second gene is not yet described.

  12. REVIEW - Advances on molecular studies of the interaction soybean - Asian rust

    Directory of Open Access Journals (Sweden)

    Aguida Maria Alves Pereira Morales

    2012-01-01

    Full Text Available Effective management practices are essential for controlling rust outbreaks. The main control methodused is the application of fungicides, which increases substantially the cost of production and is harmful to theenvironment. Prevention is still the best way to avoid more significant losses in soybean yields. Alternatives,such as planting resistant varieties to the fungus, are also important. The use of resistant or tolerant varietiesis the most promising method for controlling Asian soybean rust. Recently, five dominant genes resistant to soybean rust were described: Rpp1, Rpp2, Rpp3, Rpp4 and Rpp5. However, little is known about the molecular interaction among soybean plant and soybean rust and on the molecular pathway triggered by pathogen recognition. Understanding the molecular mechanisms involved in defense responses is of primary importance for planning strategies to control stress and, consequently, to increase plant adaptation to limiting conditions

  13. Molecular tagging of a novel rust resistance gene R(12) in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Gong, L; Hulke, B S; Gulya, T J; Markell, S G; Qi, L L

    2013-01-01

    Sunflower production in North America has recently suffered economic losses in yield and seed quality from sunflower rust (Puccinia helianthi Schwein.) because of the increasing incidence and lack of resistance to new rust races. RHA 464, a newly released sunflower male fertility restorer line, is resistant to both of the most predominant and most virulent rust races identified in the Northern Great Plains of the USA. The gene conditioning rust resistance in RHA 464 originated from wild Helianthus annuus L., but has not been molecularly marked or determined to be independent from other rust loci. The objectives of this study are to identify molecular markers linked to the rust resistance gene and to investigate the allelism of this gene with the unmapped rust resistance genes present in HA-R6, HA-R8 and RHA 397. Virulence phenotypes of seedlings for the F(2) population and F(2:3) families suggested that a single dominant gene confers rust resistance in RHA 464, and this gene was designated as R(12). Bulked segregant analysis identified ten markers polymorphic between resistant and susceptible bulks. In subsequent genetic mapping, the ten markers covered 33.4 cM of genetic distance on linkage group 11 of sunflower. A co-dominant marker CRT275-11 is the closest marker distal to R(12) with a genetic distance of 1.0 cM, while ZVG53, a dominant marker linked in the repulsion phase, is proximal to R(12) with a genetic distance of 9.6 cM. The allelism test demonstrated that R(12) is not allelic to the rust resistance genes in HA-R6, HA-R8 and RHA 397, and it is also not linked to any previously mapped rust resistance genes. Discovery of the R(12) novel rust resistance locus in sunflower and associated markers will potentially support the molecular marker-assisted introgression and pyramiding of R(12) into sunflower breeding lines.

  14. ENZYMATIC KINETIC STUDY HYDROLASE FROM CITRUS

    Directory of Open Access Journals (Sweden)

    Israel Hernández

    2015-09-01

    Full Text Available In this paper the degrading activity of enzymes derived from orange peels (Citrus x sinensis, grapefruit (Citrus paradise and pineapple (Ananas comosus on the organic matter in wastewater is evaluated. This activity is measured indirectly by quantifying the biochemical oxygen demand (COD before and after degradation process based on a period of time using the HACH DR / 2010, and then the kinetic study was performed by the differential method and integral with the experimental data, obtaining a reaction order of 1 to pectinase (orange, and order 2 for bromelain (pineapple.

  15. Plant MITEs: Useful Tools for Plant Genetics and Genomics

    Institute of Scientific and Technical Information of China (English)

    Ying Feng

    2003-01-01

    MITEs (Miniature inverted-repeat transposable elements) are reminiscence of non-autonomous DNA (class Ⅱ) elements, which are distinguished from other transpos-able elements by their small size, short terminal inverted repeats (TIRs), high copynumbers, genic preference, and DNA sequence identity among family members. Al-though MITEs were first discovered in plants and still actively reshaping genomes,they have been isolated from a wide range of eukaryotic organisms. MITEs canbe divided into Tourist-like, Stowaway-like, and pogo-like groups, according tosimilarities of their TIRs and TSDs (target site duplications). In despite of sev-eral models to explain the origin and amplification of MITEs, their mechanisms oftransposition and accumulation in eukaryotic genomes remain poorly understoodowing to insufficient experimental data. The unique properties of MITEs have beenexploited as useful genetic tools for plant genome analysis. Utilization of MITEsas effective and informative genomic markers and potential application of MITEsin plants systematic, phylogenetic, and genetic studies are discussed.

  16. Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi.

    Directory of Open Access Journals (Sweden)

    Diane G O Saunders

    Full Text Available Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i contain a secretion signal, (ii are encoded by in planta induced genes, (iii have similarity to haustorial proteins, (iv are small and cysteine rich, (v contain a known effector motif or a nuclear localization signal, (vi are encoded by genes with long intergenic regions, (vii contain internal repeats, and (viii do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components.

  17. Using Hierarchical Clustering of Secreted Protein Families to Classify and Rank Candidate Effectors of Rust Fungi

    Science.gov (United States)

    Saunders, Diane G. O.; Win, Joe; Cano, Liliana M.; Szabo, Les J.; Kamoun, Sophien; Raffaele, Sylvain

    2012-01-01

    Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i) contain a secretion signal, (ii) are encoded by in planta induced genes, (iii) have similarity to haustorial proteins, (iv) are small and cysteine rich, (v) contain a known effector motif or a nuclear localization signal, (vi) are encoded by genes with long intergenic regions, (vii) contain internal repeats, and (viii) do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components. PMID:22238666

  18. Nasal mites of Tyrannidae (Aves in Brazil

    Directory of Open Access Journals (Sweden)

    MM. Mendes

    Full Text Available A total of 81 Tyraniidae birds were examined, 80 Pitangus sulphuratus (Linnaeus, 1766 (Great kiscadee, and one Machetornis rixosa (Vieilot, 1819 (Cattle tyrant, for collection of nasal mites, which were identified as Ptilonyssus spinosus (Brooks & Strandtmann, 1960 and Sternostoma longisetosae (Hyland, 1961 (Rhinonyssidae. This finding characterises the first report of P. spinosus and S. longisetosae in P. sulphuratus, and the first record of P. spinosus in M. rixosa, and expands the geographic distribution of these species. It is the first occurrence of S. longisetosae in the Neotropics, and the first citation of P. spinosus in the state of Rio Grande do Sul, Brazil.

  19. Democracia: límites y perspectivas

    OpenAIRE

    Bolívar Espinoza, Gardy Augusto; Castro Herrera, Guillermo; Cuéllar Saavedra, Óscar; Dewey, John; Editorial, Equipo; Fernández Buey, Francisco; Fernández Nadal, Estela; Guevara Avila, Jean Paul; Gumucio, Rafael; Habermas, Jürgen; Hardin, Garrett; Hinkelammert, Franz; Oquendo, Ángel; Pizarro, Roberto; Portales, Felipe

    2005-01-01

    Para quienes hemos vivido largos períodos dictatoriales habiendo tenido previamente la experiencia de conocer los horizontes que abre y a la vez sus límites, la democracia es como el aire que respiramos: mientras lo tenemos no nos damos cuenta de su valor y de su necesidad, si nos falta hay que ver cómo nos duele. Sin embargo la democracia no es ni fácil ni placentera a veces; como lo señalara Estanislao Zuleta, “la democracia implica la aceptación de un cierto grado de angustia”. No es una p...

  20. 454-pyrosequencing of Coffea arabica leaves infected by the rust fungus Hemileia vastatrix reveals in planta-expressed pathogen-secreted proteins and plant functions in a late compatible plant-rust interaction

    OpenAIRE

    Fernandez, Diana; Tisserant, E.; Talhinhas, P.; Azinheira, H; Vieira, A.; Petitot, Anne-Sophie; Loureiro, A.; Poulain, J.; Da Silva, C; Silva, M. D. C.; Duplessis, S.

    2012-01-01

    Coffee (Coffea arabica L.), one of the key export and cash crops in tropical and subtropical countries, suffers severe losses from the rust fungus Hemileia vastatrix. The transcriptome of H. vastatrix was analysed during a compatible interaction with coffee to obtain an exhaustive repertoire of the genes expressed during infection and to identify potential effector genes. Large-scale sequencing (454-GS-FLEX Titanium) of mixed coffee and rust cDNAs obtained from 21-day rust-infected leaves gen...

  1. 16 CFR 23.10 - Misuse of “corrosion proof,” “noncorrosive,” “corrosion resistant,” “rust proof,” “rust resistant...

    Science.gov (United States)

    2010-01-01

    ... INDUSTRIES § 23.10 Misuse of “corrosion proof,” “noncorrosive,” “corrosion resistant,” “rust proof,” “rust resistant,” etc. (a) It is unfair or deceptive to: (1) Use the terms “corrosion proof,” “noncorrosive... the product will be immune from rust and other forms of corrosion during the life expectancy of the...

  2. Development of SSR markers from Citrus clementina (Rutaceae) BAC end sequences and interspecific transferability in Citrus.

    Science.gov (United States)

    Ollitrault, Frédérique; Terol, Javier; Pina, Jose Antonio; Navarro, Luis; Talon, Manuel; Ollitrault, Patrick

    2010-11-01

    Microsatellite primers were developed from bacterial artificial chromosome (BAC) end sequences of Citrus clementina and their transferability and polymorphism tested in the genus Citrus for future anchorage of physical and genetic maps and comparative interspecific genetic mapping. • Using PAGE and DNA silver staining, 79 primer pairs were selected for their transferability and polymorphism among 526 microsatellites mined in BES. A preliminary diversity study in Citrus was conducted with 18 of them, in C. reticulata, C. maxima, C. medica, C. sinensis, C. aurantium, C. paradisi, C. lemon, C. aurantifolia, and some papedas (wild citrus), using a capillary electrophoresis fragment analyzer. Intra- and interspecific polymorphism was observed, and heterozygous markers were identified for the different genotypes to be used for genetic mapping. • These results indicate the utility of the developed primers for comparative mapping studies and the integration of physical and genetic maps.

  3. House dust mites and their allergens at selected locations in the homes of house dust mite-allergic patients

    DEFF Research Database (Denmark)

    Sidenius, K E; Hallas, T E; Brygge, T

    2002-01-01

    Knowledge of the occurrence of house dust mites (HDM) and their allergens in domestic locations is important when planning intervention.......Knowledge of the occurrence of house dust mites (HDM) and their allergens in domestic locations is important when planning intervention....

  4. Mattress encasings and mite allergen levels in the Prevention and Incidence of Asthma and Mite Allergy study

    NARCIS (Netherlands)

    van Strien, RT; Koopman, LP; Kerkhof, M; Oldenwening, M; de Jongste, JC; Gerritsen, J; Neijens, HJ; Aalberse, RC; Smit, HA; Brunekreef, B

    2003-01-01

    Background Reduction of allergen exposure from birth may reduce sensitization and subsequent allergic disease. Objective To measure the influence of mite allergen-impermeable mattress encasings and cotton placebo encasings on the amount of dust and mite allergen in beds. Methods A total of 810 child

  5. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small 'laying hen' cages

    NARCIS (Netherlands)

    Lesna, Izabela; Sabelis, Maurice W.; van Niekerk, Thea G. C. M.; Komdeur, Jan

    2012-01-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in

  6. Mattress encasings and mite allergen levels in the Prevention and Incidence of Asthma and Mite Allergy study

    NARCIS (Netherlands)

    van Strien, RT; Koopman, LP; Kerkhof, M; Oldenwening, M; de Jongste, JC; Gerritsen, J; Neijens, HJ; Aalberse, RC; Smit, HA; Brunekreef, B

    2003-01-01

    Background Reduction of allergen exposure from birth may reduce sensitization and subsequent allergic disease. Objective To measure the influence of mite allergen-impermeable mattress encasings and cotton placebo encasings on the amount of dust and mite allergen in beds. Methods A total of 810 child

  7. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small 'laying hen' cages

    NARCIS (Netherlands)

    Lesna, Izabela; Sabelis, Maurice W.; van Niekerk, Thea G. C. M.; Komdeur, Jan

    2012-01-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in

  8. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small ‘laying hen’ cages

    NARCIS (Netherlands)

    Lesna, I.; Sabelis, M.W.; van Niekerk, T.G.C.M.; Komdeur, J.

    2012-01-01

    o assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in

  9. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small ‘laying hen’ cages

    NARCIS (Netherlands)

    Lesna, I.; Sabelis, M.W.; Niekerk, van T.G.C.M.; Komdeur, J.

    2012-01-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in

  10. Disruption of Rpp1-mediated soybean rust immunity by virus-induced gene silencing.

    Science.gov (United States)

    Cooper, Bret; Campbell, Kimberly B; McMahon, Michael B; Luster, Douglas G

    2013-01-01

    Phakopsora pachyrhizi, a fungus that causes rust disease on soybean, has potential to impart significant yield loss and disrupt food security and animal feed production. Rpp1 is a soybean gene that confers immunity to soybean rust, and it is important to understand how it regulates the soybean defense system and to use this knowledge to protect commercial crops. It was previously discovered that some soybean proteins resembling transcription factors accumulate in the nucleus of Rpp1 soybeans. To determine if they contribute to immunity, Bean pod mottle virus was used to attenuate or silence the expression of their genes. Rpp1 plants subjected to virus-induced gene silencing exhibited reduced amounts of RNA for 5 of the tested genes, and the plants developed rust-like symptoms after subsequent inoculation with fungal spores. Symptoms were associated with the accumulation of rust fungal RNA and protein. Silenced plants also had reduced amounts of RNA for the soybean Myb84 transcription factor and soybean isoflavone O-methyltransferase, both of which are important to phenylpropanoid biosynthesis and lignin formation, crucial components of rust resistance. These results help resolve some of the genes that contribute to Rpp1-mediated immunity and improve upon the knowledge of the soybean defense system. It is possible that these genes could be manipulated to enhance rust resistance in otherwise susceptible soybean cultivars.

  11. A key role for green rust in the Precambrian oceans and the genesis of iron formations

    Science.gov (United States)

    Halevy, I.; Alesker, M.; Schuster, E. M.; Popovitz-Biro, R.; Feldman, Y.

    2017-01-01

    Iron formations deposited in marine settings during the Precambrian represent large sinks of iron and silica, and have been used to reconstruct environmental conditions at the time of their formation. However, the observed mineralogy in iron formations, which consists of iron oxides, silicates, carbonates and sulfides, is generally thought to have arisen from diagenesis of one or more mineral precursors. Ferric iron hydroxides and ferrous carbonates and silicates have been identified as prime candidates. Here we investigate the potential role of green rust, a ferrous-ferric hydroxy salt, in the genesis of iron formations. Our laboratory experiments show that green rust readily forms in early seawater-analogue solutions, as predicted by thermodynamic calculations, and that it ages into minerals observed in iron formations. Dynamic models of the iron cycle further indicate that green rust would have precipitated near the iron redoxcline, and it is expected that when the green rust sank it transformed into stable phases within the water column and sediments. We suggest, therefore, that the precipitation and transformation of green rust was a key process in the iron cycle, and that the interaction of green rust with various elements should be included in any consideration of Precambrian biogeochemical cycles.

  12. A summary of information on the rust Puccinia psidii Winter (guava rust) with emphasis on means to prevent introduction of additional strains to Hawaii

    Science.gov (United States)

    Loope, Lloyd

    2010-01-01

    The neotropical rust fungus Puccinia psidii(P. psidii) was originally described from the host common guava in its native Brazil but has been found since on hosts throughout the myrtle family (Myrtaceae), including a dramatic host jump to nonnative Eucalyptus plantations. Most rust fungi are able to live only on a very narrow range of host species. P. psidii is unusual both for having a broad host range and for the intensity of its damage to susceptible young growth. This rust first got a foothold in the United States in Florida more than three decades ago. The U.S. Department of Agriculture (USDA) has since considered it a nonactionable, nonreportable pest. Hawaii and Florida are the only two states with native species in the myrtle family. Over a period of 30 years, this rust has done little damage to any of the scattered native Myrtaceae in Florida, although the host range of the rust has gradually grown to about 30 mostly nonnative species in the family, apparently because of increasing genetic variety of the rust by repeated introductions. However, Florida’s native Myrtaceae are among the roughly 1,100 neotropical species that are largely resistant to P. psidii. The 3,000 species of non-neotropical Myrtaceae of the Pacific, Australia, Asia, and Africa are expected to prove much more vulnerable to P. psidii. Little is known about the genetics or genetic strains of P. psidii, although existing literature shows that there are numerous strains that have differential ability to infect suites of host plants.

  13. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small 'laying hen' cages.

    Science.gov (United States)

    Lesna, Izabela; Sabelis, Maurice W; van Niekerk, Thea G C M; Komdeur, Jan

    2012-12-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in cages, each with 2-3 laying hens, initially 300 poultry red mites and later the release of 1,000 predators. These small-scale tests were designed to prevent mite escape from the cages and they were carried out in three replicates at each of three temperature regimes: 26, 30 (constant day and night) and 33-25 °C (day-night cycle). After 6 weeks total population sizes of poultry red mites and predatory mites were assessed. For the temperature regimes of 26 and 33/25 °C S. scimitus reduced the poultry red mite population relative to the control experiments by a factor 3 and 30, respectively, and A. casalis by a factor of 18 and 55, respectively. At 30 °C the predators had less effect on red mites, with a reduction of 1.3-fold for S. scimitus and 5.6-fold for A. casalis. This possibly reflected hen manure condition or an effect of other invertebrates in the hen feed. Poultry red mite control was not negatively affected by temperatures as high as 33 °C and was always better in trials with A. casalis than in those with S. scimitus. In none of the experiments predators managed to eradicate the population of poultry red mites. This may be due to a prey refuge effect since most predatory mites were found in and around the manure tray at the bottom of the cage, whereas most poultry red mites were found higher up in the cage (i.e. on the walls, the cover, the perch, the nest box and the food box). The efficacy of applying predatory mites in the poultry industry may be promoted by reducing this refuge effect, boosting predatory mite populations using alternative prey and prolonged predator release devices. Biocontrol success, however, will strongly depend on how the poultry is

  14. Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; SHI Xue-gen; WEI You-zhang; YANG Xiao-e; UOTI Juhani

    2006-01-01

    Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to studythe effects of compound fertilizers on their yieldsand quality. In the citrus experiment, application of compound fertilizers increased available P,K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51, 0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea.Optimal rates of compound fertilizers were recommended for both crops.

  15. Citrus leprosis virus N: A New Dichorhavirus Causing Citrus Leprosis Disease.

    Science.gov (United States)

    Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Tassi, Aline Daniele; Kitajima, Elliot Watanabe; Harakava, Ricardo; Salaroli, Renato Barbosa; Freitas-Astúa, Juliana

    2017-08-01

    Citrus leprosis (CL) is a viral disease endemic to the Western Hemisphere that produces local necrotic and chlorotic lesions on leaves, branches, and fruit and causes serious yield reduction in citrus orchards. Samples of sweet orange (Citrus × sinensis) trees showing CL symptoms were collected during a survey in noncommercial citrus areas in the southeast region of Brazil in 2013 to 2016. Transmission electron microscopy analyses of foliar lesions confirmed the presence of rod-like viral particles commonly associated with CL in the nucleus and cytoplasm of infected cells. However, every attempt to identify these particles by reverse-transcription polymerase chain reaction tests failed, even though all described primers for the detection of known CL-causing cileviruses and dichorhaviruses were used. Next-generation sequencing of total RNA extracts from three symptomatic samples revealed the genome of distinct, although highly related (>92% nucleotide sequence identity), viruses whose genetic organization is similar to that of dichorhaviruses. The genome sequence of these viruses showed citrus trees and those used for the transmission of one of the characterized isolates to Arabidopsis plants were anatomically recognized as Brevipalpus phoenicis sensu stricto. Molecular and biological features indicate that the identified viruses belong to a new species of CL-associated dichorhavirus, which we propose to call Citrus leprosis N dichorhavirus. Our results, while emphasizing the increasing diversity of viruses causing CL disease, lead to a reevaluation of the nomenclature of those viruses assigned to the genus Dichorhavirus. In this regard, a comprehensive discussion is presented.

  16. Computational identification of citrus microRNAs and target analysis in citrus expressed sequence tags.

    Science.gov (United States)

    Song, C; Jia, Q; Fang, J; Li, F; Wang, C; Zhang, Z

    2010-11-01

    MicroRNAs (miRNAs) are a new family of small RNA molecules found in plants and animals. We developed a comprehensive strategy for identifying new miRNA homologues by mining the repository of available citrus expressed sequence tags (ESTs). By adopting a range of filtering criteria, we identified a total of 38 potential miRNAs--nine, five, nine and 15 miRNAs in Citrus trifoliata (ctr-miRNAs), C. clementina (ccl-miRNAs), C. reticulata (crt-miRNAs) and C. sinensis (csi-miRNAs), respectively--from more than 430,000 EST sequences in citrus. Using the potential miRNA sequences, we conducted a further BLAST search of the mRNA database and found six potential target genes in these citrus species. Eight miRNAs were selected in order to verify their existence in citrus using Northern blotting, and the functions of several miRNAs in miRNA-mediated gene regulation are experimentally suggested. It appears that all these miRNAs regulate expression of their target genes by cleavage, which is the most common situation in gene regulation mediated by plant miRNAs. Our achievement in identifying new miRNAs in citrus provides a powerful incentive for further studies on the important roles of these miRNAs.

  17. Preliminary Studies on Species and Distribution of Citrus Viroids in China

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-feng; ZHOU Chang-yong; TANG Ke-zhi; LAN Jian-qiang; ZHOU Yan; LI Zhon-gan

    2008-01-01

    Citrus viroids are the small but economically important RNA pathogens.For investigating their occurrence and distribution in China,65 viroid samples collected from 8 major citrus cultivated regions were evaluated using one-step or multiplex one-step RT-PCR and biological indexing for specifically detection of Citrus exocortis viroid (CEVd),Citrus bent leaf viroid (CBLVd),Hop stunt viroid (HSVd),Citrus viroid-ⅢI (CVd-Ⅲ) and Citrus viroid-Ⅳ (CVd-Ⅳ).The results showed that there were at least 4 kinds of citrus viroids (CEVd,CBLVd,HSVd,and CVd-Ⅲ) on citrus trees in China.Most of the infected citrus plants harbored more than one viroid species,and two plants were infected with up to 4 citrus viroids.Sweet orange was more frequently infected by viroids than other citrus varieties.It is the preliminary report on the species and distribution of citrus viroids in China.

  18. Diversity of endophytic bacterial populations and their interaction with Xylella fastidiosa in citrus plants

    NARCIS (Netherlands)

    Araujo, W.L.; Marcon, J.; jr. Maccheroni, W.; Elsas, van J.D.; Vuurde, van J.W.L.; Azevedo, de J.L.

    2002-01-01

    Citrus variegated chlorosis (CVC) is caused by Xylella fastidiosa, a phytopathogenic bacterium that can infect all Citrus sinensis cultivars. The endophytic bacterial communities of healthy, resistant, and CVC-affected citrus plants were studied by using cultivation as well as

  19. Decay of house-dust mite allergen Der f 1 at indoor climatic conditions

    DEFF Research Database (Denmark)

    Sidenius, Kirsten E; Hallas, Thorkil E; Stenderup, Jørgen;

    2002-01-01

    The decay of house-dust mite allergens is important for the outcome of avoidance measures for house-dust mite-allergic patients.......The decay of house-dust mite allergens is important for the outcome of avoidance measures for house-dust mite-allergic patients....

  20. Failure of the mite-pathogenic fungus Neozygites tanajoae and the predatory mite Neoseiulus idaeus to control a population of the cassava green mite, Mononychellus tanajoa.

    Science.gov (United States)

    Elliot, Simon L; de Moraes, Gilberto J; Mumford, John D

    2008-12-01

    Monitoring of a population of the phytophagous cassava green mite, Mononychellus tanajoa (Bondar), and its natural enemies was undertaken in central Bahia, Brazil, in mid-1996. In spite of the presence of extremely high densities of the predatory phytoseiid mite Neoseiulus idaeus Denmark & Muma, the phytophagous mite population reached such high densities itself that there was total overexploitation of the cassava plants, leading to total leaf loss. Meanwhile, the mite-pathogenic fungus Neozygites tanajoae Delalibera, Humber & Hajek did not affect the M. tanajoa population in its growth phase as there was no inoculum present, even though we predict from a simple regression model that there was the potential for epizootics at that time. Soon after the M. tanajoa population crashed due to defoliation, there could have been an epizootic but there were simply no mite hosts to infect. These data demonstrate the ineffectiveness of one natural enemy (the predator) in terms of prey population regulation and demonstrate the importance of timing in the possible effectiveness of the other (the pathogen). For the pathogen, this probably explains its sporadic effect on host populations as previously reported. We conclude that the fungus is likely to be most useful as an adjunct to biological control with predatory mites other than N. idaeus.

  1. Molecular mapping of stem rust resistance loci effective against the Ug99 race group of the stem rust pathogen and identification of SNP marker linked to stem rust resistance gene Sr28

    Science.gov (United States)

    Wheat landrace PI 177906 has field resistance to the Ug99 race group and seedling resistance to stem rust caused by Puccinia graminis f. sp. tritici (Pgt) races TTKSK, TTKST, and BCCBC. Two populations were developed from a cross between PI 177906 and LMPG-6, 138 double haploid (DH) lines and 140 re...

  2. Rheology and composition of processed citrus fiber

    Science.gov (United States)

    While fibrous byproducts are abundant in supply, using them in food products in such a way to not degrade taste or texture can be challenging. Citrus fibers have been shown to have high water holding and viscous properties. However, to better incorporate dried orange pulp into foods, their propert...

  3. Detection of Citrus Trees from Uav Dsms

    Science.gov (United States)

    Ok, A. O.; Ozdarici-Ok, A.

    2017-05-01

    This paper presents an automated approach to detect citrus trees from digitals surface models (DSMs) as a single source. The DSMs in this study are generated from Unmanned Aerial Vehicles (UAVs), and the proposed approach first considers the symmetric nature of the citrus trees, and it computes the orientation-based radial symmetry in an efficient way. The approach also takes into account the local maxima (LM) information to verify the output of the radial symmetry. Our contributions in this study are twofold: (i) Such an integrated approach (symmetry + LM) has not been tested to detect (citrus) trees (in orchards), and (ii) the validity of such an integrated approach has not been experienced for an input, e.g. a single DSM. Experiments are performed on five test patches. The results reveal that our approach is capable of counting most of the citrus trees without manual intervention. Comparison to the state-of-the-art reveals that the proposed approach provides notable detection performance by providing the best balance between precision and recall measures.

  4. New Pseudomonas spp. Are Pathogenic to Citrus.

    Directory of Open Access Journals (Sweden)

    Farid Beiki

    Full Text Available Five putative novel Pseudomonas species shown to be pathogenic to citrus have been characterized in a screening of 126 Pseudomonas strains isolated from diseased citrus leaves and stems in northern Iran. The 126 strains were studied using a polyphasic approach that included phenotypic characterizations and phylogenetic multilocus sequence analysis. The pathogenicity of these strains against 3 cultivars of citrus is demonstrated in greenhouse and field studies. The strains were initially grouped phenotypically and by their partial rpoD gene sequences into 11 coherent groups in the Pseudomonas fluorescens phylogenetic lineage. Fifty-three strains that are representatives of the 11 groups were selected and analyzed by partial sequencing of their 16S rRNA and gyrB genes. The individual and concatenated partial sequences of the three genes were used to construct the corresponding phylogenetic trees. The majority of the strains were identified at the species level: P. lurida (5 strains, P. monteilii (2 strains, P. moraviensis (1 strain, P. orientalis (16 strains, P. simiae (7 strains, P. syringae (46 strains, distributed phylogenetically in at least 5 pathovars, and P. viridiflava (2 strains. This is the first report of pathogenicity on citrus of P. orientalis, P. simiae, P. lurida, P. moraviensis and P. monteilii strains. The remaining 47 strains that could not be identified at the species level are considered representatives of at least 5 putative novel Pseudomonas species that are not yet described.

  5. Founder lines for improved citrus biotechnology

    Science.gov (United States)

    This article discusses the research needed to develop the RMCE strategy and molecular assays for site-specific recombinases as tools for genome manipulation. Explanation of genetic engineering used to generate transgenic citrus plants to exhibit a novel phenotype, but not to contain the recombinase...

  6. Ecology of the Asian citrus pysllid

    Science.gov (United States)

    Host selection by psyllids in general appears to involve taste rather than olfaction. Adults are often less discriminating than nymphs. A priori, there is good reason to doubt that Asian citrus psyllid (ACP) uses a long-distance sex pheromone or that ACP orients to host plant volatiles over large (m...

  7. New Pseudomonas spp. Are Pathogenic to Citrus.

    Science.gov (United States)

    Beiki, Farid; Busquets, Antonio; Gomila, Margarita; Rahimian, Heshmat; Lalucat, Jorge; García-Valdés, Elena

    2016-01-01

    Five putative novel Pseudomonas species shown to be pathogenic to citrus have been characterized in a screening of 126 Pseudomonas strains isolated from diseased citrus leaves and stems in northern Iran. The 126 strains were studied using a polyphasic approach that included phenotypic characterizations and phylogenetic multilocus sequence analysis. The pathogenicity of these strains against 3 cultivars of citrus is demonstrated in greenhouse and field studies. The strains were initially grouped phenotypically and by their partial rpoD gene sequences into 11 coherent groups in the Pseudomonas fluorescens phylogenetic lineage. Fifty-three strains that are representatives of the 11 groups were selected and analyzed by partial sequencing of their 16S rRNA and gyrB genes. The individual and concatenated partial sequences of the three genes were used to construct the corresponding phylogenetic trees. The majority of the strains were identified at the species level: P. lurida (5 strains), P. monteilii (2 strains), P. moraviensis (1 strain), P. orientalis (16 strains), P. simiae (7 strains), P. syringae (46 strains, distributed phylogenetically in at least 5 pathovars), and P. viridiflava (2 strains). This is the first report of pathogenicity on citrus of P. orientalis, P. simiae, P. lurida, P. moraviensis and P. monteilii strains. The remaining 47 strains that could not be identified at the species level are considered representatives of at least 5 putative novel Pseudomonas species that are not yet described.

  8. Quantitative distribution of 'Candidatus Liberibacter asiaticus' in citrus plants with citrus huanglongbing.

    Science.gov (United States)

    Li, Wenbin; Levy, Laurene; Hartung, John S

    2009-02-01

    Citrus huanglongbing (HLB), or greening disease, is strongly associated with any of three nonculturable gram-negative bacteria belonging to 'Candidatus Liberibacter spp.' 'Ca. Liberibacter spp.' are transmitted by citrus psyllids to all commercial cultivars of citrus. The diseases can be lethal to citrus and have recently become widespread in both São Paulo, Brazil, and Florida, United States, the locations of the largest citrus industries in the world. Asiatic HLB, the form of the disease found in Florida, is associated with 'Ca. Liberibacter asiaticus' and is the subject of this report. The nonculturable nature of the pathogen has hampered research and little is known about the distribution of 'Ca. L. asiaticus' in infected trees. In this study, we have used a quantitative polymerase chain reaction assay to systematically quantify the distribution of 'Ca. L. asiaticus' genomes in tissues of six species of citrus either identified in the field during survey efforts in Florida or propagated in a greenhouse in Beltsville, MD. The populations of 'Ca. L. asiaticus' inferred from the distribution of 16S rDNA sequences specific for 'Ca. L. asiaticus' in leaf midribs, leaf blades, and bark samples varied by a factor of 1,000 among samples prepared from the six citrus species tested and by a factor of 100 between two sweet orange trees tested. In naturally infected trees, above-ground portions of the tree averaged 10(10) 'Ca. L. asiaticus' genomes per gram of tissue. Similar levels of 'Ca. L. asiaticus' genomes were observed in some but not all root samples from the same plants. In samples taken from greenhouse-inoculated trees, levels of 'Ca. L. asiaticus' genomes varied systematically from 10(4) genomes/g at the graft inoculation site to 10(10) genomes/g in some leaf petioles. Root samples from these trees also contained 'Ca. L. asiaticus' at 10(7) genomes/g. In symptomatic fruit tissues, 'Ca. L. asiaticus' genomes were also readily detected and quantified. The highest

  9. Bartonella-like bacteria carried by domestic mite species.

    Science.gov (United States)

    Kopecký, Jan; Nesvorná, Marta; Hubert, Jan

    2014-01-01

    Bacteria of the genus Bartonella are carried by haematophagous mites, ticks, fleas and flies, and attack the erythrocytes of mammals. Here we describe a Bartonella-like clade, a distinct group related to Bartonellaceae, in stored-product mites (Acari: Astigmata) and a predatory mite Cheyletus eruditus (Acari: Prostigmata) based on the analysis of cloned 16S rRNA gene sequences. By using the clade-specific primers, closely related Bartonella-like 16S rRNA sequences were amplified from both laboratory colonies and field strains of three synanthropic mite species (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae) and a predatory mite. Altogether, sequences of Bartonella-like bacteria were found in 11 strains, but were not detected in Dermatophagoides farinae and D. pteronyssinus and two strains of L. destructor. All obtained sequences formed a separate cluster branching as a sister group to Bartonellaceae and related to other separate clusters comprising uncultured bacterial clones from human skin and hemipteran insects (Nysius plebeius and Nysius sp.). The classification of sequences into operational taxonomic units (OTUs) showed a difference between A. siro and T. putrescentiae suggesting that the Bartonella-like bacteria are different in these two mite species. However, species specific sequences in separate OTUs were observed also for C. eruditus. Possible symbiotic interactions between Bartonella-like bacteria and their mite hosts are discussed.

  10. Plant MITEs: useful tools for plant genetics and genomics.

    Science.gov (United States)

    Feng, Ying

    2003-05-01

    MITEs (Miniature inverted-repeat transposable elements) are reminiscence of non-autonomous DNA (class II) elements, which are distinguished from other transposable elements by their small size, short terminal inverted repeats (TIRs), high copy numbers, genic preference, and DNA sequence identity among family members. Although MITEs were first discovered in plants and still actively reshaping genomes, they have been isolated from a wide range of eukaryotic organisms. MITEs can be divided into Tourist-like, Stowaway-like, and pogo-like groups, according to similarities of their TIRs and TSDs (target site duplications). In despite of several models to explain the origin and amplification of MITEs, their mechanisms of transposition and accumulation in eukaryotic genomes remain poorly understood owing to insufficient experimental data. The unique properties of MITEs have been exploited as useful genetic tools for plant genome analysis. Utilization of MITEs as effective and informative genomic markers and potential application of MITEs in plants systematic, phylogenetic, and genetic studies are discussed.

  11. Pheromonal Communication in the European House Dust Mite, Dermatophagoides pteronyssinus

    Directory of Open Access Journals (Sweden)

    Johannes L.M. Steidle

    2014-08-01

    Full Text Available Despite the sanitary importance of the European house dust mite Dermatophagoides pteronyssinus (Trouessart, 1897, the pheromonal communication in this species has not been sufficiently studied. Headspace analysis using solid phase micro extraction (SPME revealed that nerol, neryl formate, pentadecane, (6Z,9Z-6,9-heptadecadiene, and (Z-8-heptadecene are released by both sexes whereas neryl propionate was released by males only. Tritonymphs did not produce any detectable volatiles. In olfactometer experiments, pentadecane and neryl propionate were attractive to both sexes as well as to tritonymphs. (Z-8-heptadecene was only attractive to male mites. Therefore it is discussed that pentadecane and neryl propionate are aggregation pheromones and (Z-8-heptadecene is a sexual pheromone of the European house dust mite D. pteronyssinus. To study the potential use of pheromones in dust mite control, long-range olfactometer experiments were conducted showing that mites can be attracted to neryl propionate over distances of at least 50 cm. This indicates that mite pheromones might be useable to monitor the presence or absence of mites in the context of control strategies.

  12. The use of soil mites in ecotoxicology: a review.

    Science.gov (United States)

    Huguier, Pierre; Manier, Nicolas; Owojori, Olugbenga John; Bauda, Pascale; Pandard, Pascal; Römbke, Jörg

    2015-01-01

    Mites, and especially soil-inhabiting ones, have been less studied than the other invertebrates used in bio-assays for the assessment of soil quality and the hazards of chemicals, although these organisms are included in the regulatory assessment scheme of pesticides. The recent advances in the development of test methods for soil mites groups have provided more information on their sensitivities towards chemicals, which needs to be presented for a more robust assessment of the current trends in soil mite ecotoxicology. Moreover, interestingly mite is the only taxa for which test methods were developed and standardized on predatory organisms. This review summarizes the different protocols for the assessment of chemicals using soil-inhabiting mites, including laboratory, semi-field and field studies. Among the data found in the literature, most of the chemicals assessed with mites were pesticides, while a few environmental samples were assessed with these organisms. Their sensitivities towards chemicals were then compared and discussed regarding other soil invertebrates. Finally, we conclude on the usefulness of soil mites in ecotoxicology, and provide future research trail in this area.

  13. Do Demodex mites play a role in pterygium development?

    Science.gov (United States)

    Tarkowski, Witold; Moneta-Wielgoś, Joanna; Młocicki, Daniel

    2017-01-01

    Numerous reports point to Demodex mites as the aetiology of certain eye and skin conditions, hence it is highly probable that infestation with these mites may also play a role in the aetiology and pathogenesis of pterygium. Therefore here we present a hypothesis: whether the presence of Demodex mites in eyelash hair follicles significantly correlates with the presence of pterygia, which could point to a potential role of these mites in the development of such lesions. We present preliminary data for supporting this hypothesis. These results were collected from a group of 69 subjects, including 39 with pterygium. Subjects were studied for the presence of Demodex folliculorum and/or D. brevis within eyelash follicles. The sample was defined as positive if at least one parasite, larva or egg were present. Preliminary statistical analyses were performed, and indicated a significant relationship between Demodex mite infestation and the presence of pterygium (pDemodex infestation formed a dominant group. The proportion of subjects with both pterygia and Demodex presence is high at 93.33%, while the proportion of subjects without pterygia who have mites is low at 20.51%. Aforementioned results support our working hypothesis that infestation with Demodex mites may result in pterygium development and therefore patients diagnosed with pterygium should be assessed for the presence of Demodex to verify our preliminary results. In the present paper, we discuss potential influence of Demodex on conjunctiva and propose a hypothetical pathological mechanism linking the development of pterygia with demodicosis.

  14. Breeding the Mite-Resistant Honeybee by Nutritional Crossbreed Technology

    Institute of Scientific and Technical Information of China (English)

    XIE Xian-bing; PENG Wen-jun; ZENG Zhi-jiang

    2008-01-01

    Mite (Varroa destructor) is one of the most serious parasite threats to the honey bee (Apis mellifera) reared in China. The beekeepers mainly use the drug to control and kill the mite in the past years, but the honey products may be contaminated and the mite is becoming drug-resistant. The main idea of this paper is to research the possibility of mite-resistant honeybee rearing by nutritional crossbreed. The larvae (Apis mellifera ligustica) are bred with the royal jelly of Apis carana carana, and then the morphological index of the worker generation, genotypic frequency and gene frequency of the MDH Ⅱ, genetic resemblance, and mite resistance are measured. The results show that: compared to the parent workers, the proboscis length, anterior wing area, the total length of the third and fourth dorsal plate of the abdomen, the length of the fourth dorsal plate of the tuberculum, the area of the sixth abdominal segment, and the area of wax mirrors are significantly different, but the differences in the brachium index, dactylus index, and wing claw are not significant. Moreover, there are some mutations in the genotypic frequency and gene frequency of the MDH Ⅱ. The mite resistance of the nutritional crossbreed worker is significantly higher. The morphological, physical, and biochemical characters, genetic resemblance, and the mite-resistant ability of the worker generation can be changed by nutritional crossbreeding. Nutritional crossbreeding can be a new way to breed the honeybee.

  15. Seletividade de produtos fitossanitários sobre o ácaro predador Agistemus brasiliensis Matioli, Ueckermann & Oliveira (Acari: Stigmaeidae Selectivity ofthe pesticides tothe predaceous mite Agistemus brasiliensis Matioli,, Ueckermann & Oliveira (Acari: Stigmaeidae

    Directory of Open Access Journals (Sweden)

    Marcos Zatti da Silva

    2009-06-01

    Full Text Available Os ácaros predadores das famílias Phytoseiidae e Stigmaeidae constituem-se nos principais inimigos naturais de Brevipalpus phoenicis (Geijskes em citros. Este ácaro-praga causa sérios prejuízos na produção, devido à transmissão do vírus da leprose dos citros (CiLV. Apesar do grande volume de informações sobre a sensibilidade de ácaros Phytoseiidae a agrotóxicos, praticamente não existem informações sobre o efeito desses compostos em ácaros Stigmaeidae no Brasil. Sendo assim, o trabalho teve por objetivo avaliar o efeito dos principais agrotóxicos utilizados em citros sobre o ácaro predador Agistemus brasiliensis Matioli, Ueckermann & Oliveira (Acari: Stigmaeidae, em condições de laboratório. Arenas de folhas de citros da variedade Pera, contendo 25 fêmeas adultas de A. brasiliensis, foram pulverizadas em torre de Potter. Avaliaram-se as mortalidades dos ácaros 72 horas após a aplicação. O efeito dos produtos na reprodução do acarino e a viabilidade dos ovos também foram avaliados. Quanto à seletividade, conforme proposta da "Organização Internacional para o Controle Biológico" (IOBC, os produtos foram classificados como: classe 1 - inócuo (E99%, calda sulfocálcica, cyhexatin, flufenoxuron, hexythiazox, óxido de fenbutatin, propargite, pyridaben e spirodiclofen. Estudos conduzidos em condições de campo ainda são necessários para se compreender melhor o efeito desses agrotóxicos sobre o ácaro predador.The predaceous mites of the families Phytoseiidae and Stigmaeidae are the most important natural enemies of Brevipalpus phoenicis (Geijskes on citrus. This mite causes serious damages to the yield due to the transmission of Citrus leprosis virus (CiLV. Despite the considerable amount of information on susceptibility of phytoseiids to pesticides, the effect of these compounds is not very known for stigmaeid mites in Brazil. This work was carried out to evaluate the effect of the main pesticides used in

  16. Citrus tristeza virus-host interactions

    Directory of Open Access Journals (Sweden)

    William O. Dawson

    2013-05-01

    Full Text Available Citrus tristeza virus (CTV is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably from that of well-studied viruses of herbaceous plants where movement occurs largely through adjacent cells. In contrast, CTV systemically infects plants mainly by long-distance movement with only limited cell-to-cell movement. The virus is transported through sieve elements and occasionally enters an adjacent companion or phloem parenchyma cell where virus replication occurs. In some plants this is followed by cell-to-cell movement into only a small cluster of adjacent cells, while in others there is no cell-to-cell movement. Different proportions of cells adjacent to sieve elements become infected in different plant species. This appears to be related to how well viral gene products interact with specific hosts. CTV has three genes that are not necessary for infection of most of its hosts, but are needed in different combinations for infection of certain citrus species. These genes apparently were acquired by the virus to extend its host range. Some specific viral gene products have been implicated in symptom induction. Remarkably, the deletion of these genes from the virus genome can induce large increases in stem pitting symptoms. The p23 gene, which is a suppressor of RNA silencing and a regulator of viral RNA synthesis, has been shown to be the cause of seedling yellows symptoms in sour orange. Most isolates of CTV in nature are populations of different strains of CTV. The next frontier of CTV biology is the understanding how the virus variants in

  17. Slight Fermentation with Lactobacillus fermentium Improves the Taste (Sugar:Acid Ratio) of Citrus (Citrus reticulata cv. chachiensis) Juice.

    Science.gov (United States)

    Yu, Yuanshan; Xiao, Gengsheng; Xu, Yujuan; Wu, Jijun; Fu, Manqin; Wen, Jing

    2015-11-01

    The aim of this study was to evaluate the hypothesis that fermentation with Lactobacillus fermentium, which can metabolize citric acid, could be applied in improving the taste (sugar:acid ratio) of citrus juice. During fermentation, the strain of L. fermentium can preferentially utilize citric acid of citrus (Citrus reticulata cv. Chachiensis) juice to support the growth without the consumption of sugar. After 6 h of fermentation with L. fermentium at 30 °C, the sugar:acid ratio of citrus juice increased to 22:1 from 12:1, which resulted in that the hedonic scores of sweetness, acidity and overall acceptability of fermented-pasteurized citrus juice were higher than the unfermented-pasteurized citrus juice. Compared with unfermented-pasteurized citrus juice, the ORAC value and total amino acid showed a reduction, and no significant change (P > 0.05) in the L*, a*, b*, total soluble phenolics and ascorbic acid (Vc) content in the fermented-pasteurized citrus juice was observed as compared with unfermented-pasteurized citrus juice. Hence, slight fermentation with L. fermentium can be used for improving the taste (sugar:acid ratio) of citrus juice with the well retaining of quality.

  18. The Effect of Antibiotics on Associated Bacterial Community of Stored Product Mites

    OpenAIRE

    2014-01-01

    Background Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata). The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria. Methodology and Principal Findings Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescen...

  19. Examination of the responses of different genotypes of citrus to huanglongbing (citrus greening) under different conditions.

    Science.gov (United States)

    Folimonova, Svetlana Y; Robertson, Cecile J; Garnsey, Stephen M; Gowda, Siddarame; Dawson, William O

    2009-12-01

    ABSTRACT Citrus Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. The causal agent of HLB in Florida is thought to be 'Candidatus Liberibacter asiaticus'. In this work, we examined the responses of 30 different genotypes of citrus to Florida isolates of 'Ca. L. asiaticus' under controlled conditions in the greenhouse or growth room. Although 'Ca. L. asiaticus' was able to multiply in all of the plants, a wide range of responses was observed among different hosts. Based on the symptoms developed and the ability of plants to continue growth, the different genotypes were grouped into four categories: sensitive, which exhibited severe chlorosis on leaves, greatly reduced growth, and eventual death; moderately tolerant, which exhibited some scattered distinct symptoms but little or no growth reduction and no plant death; tolerant, which exhibited very minimal symptoms; and genotypes, which exhibited variable reactions. Interestingly, although 'Ca. L. asiaticus' was unevenly distributed within each particular plant, comparison of titers of the bacterium in different citrus genotypes revealed that most accumulated similar levels of 'Ca. L. asiaticus', demonstrating that there is no strict correlation between bacterial titer and severity of disease. Incubation of infected plants in the growth room with continuous light greatly affected symptoms production by reducing the time before distinctive symptoms developed and significantly increasing severity of chlorosis of leaves of all citrus genotypes. These results provide additional evidence of the correlation between disruption of phloem translocation of carbohydrates during HLB infection and the appearance of chlorotic symptoms in leaves of infected trees. We also examined interaction between 'Ca. L. asiaticus' and Citrus tristeza virus, which usually occurs in trees that become infected with HLB, and found no synergistic effect of the two pathogens. We trust that observations reported here

  20. Effects of citrus limon essential oil (Citrus limon L. on cytomorphometric changes of Candida albicans

    Directory of Open Access Journals (Sweden)

    Rina Prabajati

    2017-03-01

    Full Text Available Background: The most common fungal infection found in oral cavity is oral candidiasis, largely caused by Candida species, particularly Candida albicans (C. albicans. Candida infection can get worse since it is difficult to be treated and resistant with antifungal drugs. Therefore, new drugs and compounds as well as alternative therapies involving natural sources that have antifungal activities have continually been developed. Limonene, β-pinene, and ɣ-terpinene contained in Citrus limon essential oil have been known to have quite good antifungal activities against C. albicans. Purpose: This research aimed to examine and analyze the effects of Citrus limon essential oil on cytomorphometric changes of C. albicans. Method: The research used post test only control group design. Based on the results of the pre-elementary research on antifungal activities of Citrus limon essential oil against C. albicans, Citrus limon essential oil used in this research was on concentrations of 1.56%, 1.37%, 1.17%, 0.98%, and 0.78%. Citrus limon essential oil by C. albicans inoculum and incubated for 24 hours and 48 hours. After the incubation, those C. albicans cells were fixed, dried, and then observed using a scanning electron microscopy. Result: The most effective concentrations of Citrus limon essential oil triggering cytomorphometric changes of Candida albicans were at 1.37% and 1.56% with the incubation period of 48 hours. Conclusion: C. albicans can undergo necrosis process through cytomorphometric changes after the administration of Citrus limon essential oil at concentrations of 1.56% and 1.37% with the incubation period of 48 hours.

  1. New mite species associated with certain plant species from Guam

    Directory of Open Access Journals (Sweden)

    Gadi V.P. Reddy

    2011-04-01

    Full Text Available Several new mite species have been reported from certain plants from Guam. Most remarkably, the spider mite, Tetranychus marianae (Prostigmata: Tetranychidae and the predatory mite Phytoseius horridus (Mesostigmata: Phytoseiidae (Solanum melongena have been found on eggplant. The noneconomically important species of Brevipalpus californicus(Banks Prostigmata: Tenuipalpidae,Eupodes sp. (Acarina: Eupodidae and predator Cunaxa sp. (Prostigmata: Cunaxidae have been reported on guava (Psidium guajava L.. Also, the non-economically important species Brevipalpus californicus Prostigmata: Tenuipalpidae, Lepidoglyphus destructor (Astigmata: Glycyphagidae and a predator Amblyseius obtusus, species group Amblyseius near lentiginosus (Mesostigmata: Phytoseiidae, have been recorded on cycad (Cycas micronesica.

  2. INFLUENCE OF SALINITY ON CITRUS: A REVIEW PAPER

    Directory of Open Access Journals (Sweden)

    ADNAN Al-Yassin

    2005-04-01

    Full Text Available Due to the rapid expansion of irrigated agriculture, effi cient use of the limited water resources in arid and semi-arid regions is becoming more and more vital. However, water salinity is a major problem due to its negative infl uence on the yields of many crops. It reduces citrus trees’ growth and causes physiological disorders. Primarily salt-stress lowers net CO2 assimilation, stomatal conductance, and water potential of citrus tree leaves, in addition to accumulation of excessive concentration of Chloride or Sodium in leaves. A great deal of research indicates that citrus have the genetic potential to be salt-sensitive; however inheritance studies in citrus are scarce. In this paper the adverse of effects of salinity on physiological aspects of citrus are reviewed. The review summarizes the prevailing state of knowledge about the responses and tolerance of citrus trees to salinity.

  3. In vitro xanthine oxidase inhibitory activity of leaves, fruits and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon

    Directory of Open Access Journals (Sweden)

    Muthiah PL

    2012-07-01

    Full Text Available Aim of the study: To evaluate the in vitro xanthine oxidase inhibitory activity of the extract of leaves, fruits and peel of Citrus aurantium, Citrus limetta and Citrus limon.   Materials and Methods: Xanthine oxidase inhibitory activity was assayed spectrophotometrically under aerobic conditions and the degree of enzyme inhibition was determined by measuring the increase in absorbance at 295nm associated with uric acid formation.   Results: Among the extracts tested, the C.limetta peel extract exhibited highest potency of xanthine oxidase inhibition (IC50 40.16±0.88μg/ml. This was followed by C.aurantium peel (IC50 51.50±2.05μg/ml, C.limon peel (IC50 64.90±1.24μg/ml, C.aurantium leaf (IC5073.50±1.26μg/ml, C.limetta leaf (IC50 74.83±2.42μg/ml, C.limon leaf (IC50 76.83±2.02μg/ml, C.limetta fruit (IC50 95.16±0.60μg/ml extracts compared with the IC50 value of standard allopurinol was 6.6μg/ml.   Conclusion: Recent findings show that the occurrence of gout is increasing worldwide, possibly due to the changes in dietary habits like intake of food rich in nucleic acids, such as meat, sea foods, etc. Xanthine oxidase inhibitors such as allopurinol is the drug of choice, however it has been observed more side effects.  An alternative to allopurinol is the use of medicinal plants, We thus began our program to look for xanthine oxidase inhibitors of phytochemical origin. In conclusion, the study suggests that the leaves and peel extracts of Citrus aurantium, Citrus limetta and Citrus limon possess xanthine oxidase inhibitory activity that might be helpful in preventing or slowing the progress of gout and related disorders.

  4. Infestation dynamics of Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) in citrus orchards as affected by edaphic and climatic variables.

    Science.gov (United States)

    Laranjeira, Francisco Ferraz; Silva, Suely Xavier de Brito; de Andrade, Eduardo Chumbinho; Almeida, Décio de Oliveira; da Silva, Tibério Santos Martins; Soares, Ana Cristina Fermino; Freitas-Astúa, Juliana

    2015-08-01

    Brevipalpus phoenicis (Geijskes) is a cosmopolitan and polyphagous mite that transmits important phytoviruses, such as coffee ringspot virus, passion fruit green spot virus and Citrus leprosis virus C. To characterise the dynamics of the probability and the rate of B. phoenicis infestation in response to edaphic and climatic factors, monthly inspections were performed in nine orchards in a citrus region of the State of Bahia, Brazil, for 35 months. Three fruits per plant were examined using a magnifying glass (10×) on 21 plants distributed along a "W"-shaped path in each orchard. Meteorological data were collected from a conventional station. To determine the correlations among the climatic variables, the data were analysed using Spearman correlations. Variables were selected by principal component analysis, and those that contributed the most to differentiate the groups were evaluated via a Mann-Whitney test. Using the quantile-quantile method, the limit values for the following climatic variables were determined: temperature (24.5 °C), photoperiod (12 h), relative humidity (83%), evapotranspiration (71 mm) and rainy days (14 days). The combination of longer days, higher temperatures, lower relative humidity levels and lower evapotranspiration increased the probability of B. phoenicis infestation, whereas successive rain events decreased that risk. Infestation rates were negatively affected by relative humidity levels above 83% and were positively affected by a decreasing available soil-water fraction and increasing insolation and photoperiod.

  5. The Lr46 gene conditions partial adult-plant resistance to yellow rust, stem rust, and powdery mildew in Thatcher wheat

    Science.gov (United States)

    Disease resistance is a critical goal for many wheat improvement programs. Wheat cultivars are often attacked by multiple diseases, including the rusts and powdery mildew. F6 recombinant inbred lines (RILs) derived from the cross of Thatcher*3/CI13227 that had been previously characterized as having...

  6. Effect of white pine blister rust (Cronartium ribicola) and rust-resistance breeding on genetic variation in western white pine Pinus monticola)

    Science.gov (United States)

    M. -S. Kim; S. J. Brunsfeld; G. I. McDonald; N. B. Klopfenstein

    2003-01-01

    Western white pine (Pinus monticola) is an economically and ecologically important species from western North America that has declined over the past several decades mainly due to the introduction of blister rust (Cronartium ribicola) and reduced opportunities for regeneration. Amplified fragment length polymorphism (AFLP) was used...

  7. Development of a new anti-rust paint for rusted metal%新型带锈防锈漆的研制

    Institute of Scientific and Technical Information of China (English)

    应鹏展; 王雅晴

    2001-01-01

    A new anti-rust paint for rusted material was developed by addition of zinc phosphate, zinc oxide, aluminum tripolyphosphate, barium chromate and other auxiliaries, which result in phosphating, and chromating of rusted metal surface to obtain continuous, uniform and fine protective film. Addition of 0.05%~0.10% cobalt and manganese dryer can greatly improve drying rate of paint film. The anti-rust paint is stable in long-term storage and its parameters meet the requirement of national standard. Preparation of the title paint is simple and low cost.%研制了一种新型带锈防锈漆。通过加入磷酸锌、氧化锌、三聚磷酸铝、铬酸钡等助剂,使金属带锈表面锈层磷化、钝化,形成连续、均匀、致密的保护层。加入0.05%~0.10%的钴锰催干剂,显著提高了漆膜的干燥速度。该带锈防锈漆制备工艺简单、成本低、长期贮存性能稳定,各项指标均符合国家标准。

  8. Asian Citrus Psyllid RNAi Pathway – RNAi evidence

    OpenAIRE

    Taning, Clauvis N. T.; Eduardo C. Andrade; Hunter, Wayne B.; Olivier Christiaens; Guy Smagghe

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if t...

  9. Asian Citrus Psyllid RNAi Pathway – RNAi evidence

    OpenAIRE

    Taning, Clauvis N. T.; Andrade, Eduardo C. de; Hunter, Wayne B.; Christiaens, Olivier; Smagghe, Guy

    2016-01-01

    Diaphorina citri, known as the Asian citrus psyllid, is an important pest of citrus because it transmits a phloem-limited bacteria strongly implicated in huanglongbing (citrus greening disease). Emerging biotechnologies, such as RNA interference, could provide a new sustainable and environmentally friendly strategy for the management of this pest. In this study, genome and functional analysis were performed to verify whether the RNAi core genes are present in the Asian psyllid genome and if t...

  10. Citrus tissue culture employing vegetative explants.

    Science.gov (United States)

    Chaturvedi, H C; Singh, S K; Sharma, A K; Agnihotri, S

    2001-11-01

    Citrus being a number one fruit of the world due to its high nutritional value, huge production of fruits and fruit products, the citrus industry may be considered a major fruit industry. Though citrus orchard area in India is comparable to USA, the produce is far less, while its export is nil. Biotechnology has played an outstanding role in boosting the citrus industry, e.g., in Spain, which is now the biggest exporter of citrus fruit with the application of micrografting. Amongst the fruit trees, perhaps the maximum tissue culture research has been done in citrus during the past four decades, however, the results of practical value are meagre. The shortfalls in citrus tissue culture research and some advancements made in this direction along with bright prospects are highlighted, restricting the review to vegetative explants only. Whilst utilization of nucellar embryogenesis is limited to rootstocks, the other aspects, like, regeneration and proliferation of shoot meristems measuring 200 microm in length--a global breakthrough--of two commercially important scion species, Citrus aurantifolia and C. sinensis and an important rootstock, C. limonia, improvement of micrografting technique, cloning of the same two scion species as well as some Indian rootstock species, employing nodal stem segments of mature trees, of immense practical value have been elaborated. A rare phenomenon of shift in the morphogenetic pattern of differentiation from shoot bud differentiation to embryoid formation occurred during the long-term culture of stem callus of C. grandis. Stem callus-regenerated plants of C. aurantifolia, C. sinensis and C. grandis showed variation in their ploidy levels and a somaclonal variant of C. sinensis, which produced seedless fruits was isolated. Tailoring of rooting in microshoots to a tap root-like system by changing the inorganic salt composition of the rooting medium, resulting in 100% transplant success, and germplasm preservation through normal growth

  11. El programa del límite

    Directory of Open Access Journals (Sweden)

    Carlos Walker

    2011-07-01

    Full Text Available En el terreno estético, se afirma desde un comienzo, no hay revés del extremo. La experiencia del límite, su radicalidad, sólo se alcanza en contados lugares. Si bien se accede a dicha experiencia a través de los medios de la representación, no se trata aquí de una representación del extremo. El silencio, cercano, convoca a desplazar sus bordes, y exhibe así un movimiento que es concebido como estandarte de la producción estética. Las narraciones de lo extremo se inscriben en la estela del ar...

  12. 云南咖啡抗锈品种抗锈性丧失原因及防治对策%Cause and Preventive Countermeasures for Breakdown of Resistance to Rust in Rust Resistance Coffee Cultivars in Yunnan

    Institute of Scientific and Technical Information of China (English)

    张洪波; 白学慧; 李锦红; 李文伟; 周华; 胡永亮

    2011-01-01

    According to the occurrence of rust disease in rust resistance coffee cultivars in different growing areas in Yunnan and combined with distribution of races of rust disease in China, investigations and studies on cause for breakdown of resistance to rust in fields are carried out. Results show that interactions between host, pathogen and environment make physiological races of rust resistance coffee cultivars mutation constantly and disability. Study on persistent selection of rust resistance coffee cultivars as well as the importance of rational allocation on persistent of rust resistance of coffee cultivars are described. Measurements to control rust disease are put forward.%针对云南咖啡抗锈品种不同植区出现锈病,结合国内锈病小种分布情况,开展了咖啡大田抗锈性丧失原因的调查研究,结果表明:寄主一病原菌一环境的相互作用,使咖啡锈病生理小种不断变异,导致抗锈性丧失,阐述了持久抗锈品种选育研究和合理配置对咖啡品种抗锈持久的重要性,提出了防治锈病的措施。

  13. Induction and selection of citrus mutant by gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Jung; Oh, Seung Kyu; Lee, Hyo Yeon [Jeju National University, Jeju (Korea, Republic of)

    2010-09-15

    We have subjected to gamma-irradiation to citrus buds and then grafted onto mature citrus tree. Mutant citrus branch lines have been induced. As a result of first selection, we found the several mutant lines showing interesting phenotypes such as higher sugar content. We have selected several branches showing good qualities such as higher sweetness and/or lower acidity. Some branch lines showed over 13 .deg. Brix sugar content and below 0.9% acidity. Other mutant branch lines showed the changes of shape, size, peel thickness, and fiber contents or distribution of fruits. The results suggest that gamma-irradiation is an effective tool for induction of citrus mutant lines.

  14. Expression of a Thatcher wheat adult plant stem rust resistance QTL on chromosome arm 2BL is enhanced by Lr34

    Science.gov (United States)

    An F6 recombinant inbred line (RIL) spring wheat population derived from RL6071, a stem rust susceptible line and RL6058, a backcross line of Thatcher wheat with Lr34 that is highly resistant to stem rust, was evaluated for adult plant stem rust resistance in North Dakota in 1999, and in Kenya in 20...

  15. Enumerative and binomial sampling plans for citrus mealybug (Homoptera: pseudococcidae) in citrus groves.

    Science.gov (United States)

    Martínez-Ferrer, María Teresa; Ripollés, José Luís; Garcia-Marí, Ferran

    2006-06-01

    The spatial distribution of the citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae), was studied in citrus groves in northeastern Spain. Constant precision sampling plans were designed for all developmental stages of citrus mealybug under the fruit calyx, for late stages on fruit, and for females on trunks and main branches; more than 66, 286, and 101 data sets, respectively, were collected from nine commercial fields during 1992-1998. Dispersion parameters were determined using Taylor's power law, giving aggregated spatial patterns for citrus mealybug populations in three locations of the tree sampled. A significant relationship between the number of insects per organ and the percentage of occupied organs was established using either Wilson and Room's binomial model or Kono and Sugino's empirical formula. Constant precision (E = 0.25) sampling plans (i.e., enumerative plans) for estimating mean densities were developed using Green's equation and the two binomial models. For making management decisions, enumerative counts may be less labor-intensive than binomial sampling. Therefore, we recommend enumerative sampling plans for the use in an integrated pest management program in citrus. Required sample sizes for the range of population densities near current management thresholds, in the three plant locations calyx, fruit, and trunk were 50, 110-330, and 30, respectively. Binomial sampling, especially the empirical model, required a higher sample size to achieve equivalent levels of precision.

  16. Phylogenetic Analysis of Citrus tristeza virus Isolates of Wild Type Citrus in China

    Institute of Scientific and Technical Information of China (English)

    YI Long; ZHOU Chang-yong

    2014-01-01

    The genetic variation and phylogenetic relationships of Citrus tristeza virus (CTV) isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions (p23, p20, p13, p18, p25, p27, POL, HEL and k17) with the CTV isolates of cultivated citrus from different countries. The results showed that the divergence pattern of genomic RNA of the CTV isolates from wild type citrus was similar to that of other isolates from cultivated citrus, the 3´ proximal region was relatively conserved, and the 5´ proximal region had greater variability. The nine genomic regions of CTV isolates analyzed were found to have been under purifying selection in the evolution process. Phylogenetic analysis showed that the eleven Chinese wild CTV isolates were located at different clades and did not relfect their geographical origins, suggesting genetic diversity among the Chinese wild CTV populations. These results will aid in the understanding of molecular evolution of the Chinese CTV populations.

  17. Dermanyssus gallinae (chicken mite): an underdiagnosed environmental infestation.

    Science.gov (United States)

    Collgros, H; Iglesias-Sancho, M; Aldunce, M J; Expósito-Serrano, V; Fischer, C; Lamas, N; Umbert-Millet, P

    2013-06-01

    Dermanyssus gallinae is a mite that normally parasitizes small birds but may occasionally bite humans. We report an unusual case of an 82-year-old woman who presented with pruritus and bite-like lesions over her trunk. Other members of the household were also affected. On physical examination, mites gallinae, the small size of the mites and the fact that they leave the host after feeding means that they may not be seen at presentation, thus such infestations are likely to be underdiagnosed. Physicians should be aware that infection with this mite is possible even in patients from urban areas, and it should be included in the differential diagnosis of conditions causing recurrent pruritus unresponsive to standard treatments.

  18. Impeding movement of the poultry red mite, Dermanyssus gallinae.

    Science.gov (United States)

    Pritchard, James; Küster, Tatiana; George, David; Sparagano, Olivier; Tomley, Fiona

    2016-07-30

    The poultry red mite, Dermanyssus gallinae, is an economically important hematophagous parasite of commercial egg laying hens, also affecting domesticated birds and companion animals. Conventional control of D. gallinae through acaricidal spraying is often ineffective, creating an urgent need to identify alternative management strategies for commercial and domestic infestations. Whilst integrated pest management is being considered for D. gallinae, the potential of impeding mite 'migration' routes, to either prevent initial infestation or manage established populations, has not been researched. Here we demonstrate that barriers of insecticidal glue, double sided sticky tape and thyme oil can contain D. gallinae within a specified area of a petri dish (78-88% of total mite population) and this level of containment was significantly greater than for negative controls (p values <0.05). Further studies in poultry houses are recommended to investigate the efficacy of these barriers in real world application and identity potential for barriers as a strategy for mite control.

  19. Microbiota of Demodex mites from rosacea patients and controls.

    Science.gov (United States)

    Murillo, Nathalia; Aubert, Jérome; Raoult, Didier

    2014-01-01

    Proliferation of Demodex mites is associated with rosacea. Furthermore, Demodex-associated bacteria were suggested to play a role in the pathogenesis of rosacea. We decided to analyze Demodex microbiota. Mites were collected by standardized skin surface biopsies from patients with erythematotelangiectatic, papulopustular rosacea or from control subjects. The microbiota from each mite was characterized by 16S rRNA clone library approach. The 16S rRNA clone library consisted of 367 clones obtained from 73 extracts originating from 5 samples per study group (ETR, PPR or healthy subjects). A total of 86 species were identified with 36 as Demodex-specific microbiota. In the papulopustular group, proportions of Proteobacteria and Firmicutes increased whereas proportion of Actinobacteria decreased. Here, we report preliminary results on the microbiota of Demodex mites based on a molecular approach showing an unexpected diversity. Differences according to the host status need to be confirmed but open new perspectives for diagnostic of rosacea.

  20. Risk factors and prevalence of Demodex mites in young adults.

    Science.gov (United States)

    Horváth, Andrea; Neubrandt, Dóra Maja; Ghidán, Á; Nagy, K

    2011-06-01

    Demodex mites are ectoparasites often found in follicles of facial skin. Their role in human diseases is under investigation, and a growing number of studies indicated that they contribute to chronic inflammatory conditions of the skin, such as rosacea, blepharitis, otitis externa, alopecia and folliculitis. In our study we tested 96 healthy adults for the presence of Demodex mites. Risk factors influencing presence of mites and skin types of the tested individuals were evaluated. We found Demodex folliculorum or Demodex brevis in 17.7% of the samples, more frequently in males (21.9%) and in older adults (20%). Use of make-up seems to reduce the likelihood of Demodex carriage, while pet ownership, use of shared items and living in close contact with older adults had no significant influence of presence of mites. Demodex positive individuals described their skin to be drier, more prone to erythema, but less for folliculitis compared to Demodex negative subjects.

  1. FDA Approves New Treatment for Dust Mite Allergies

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163882.html FDA Approves New Treatment for Dust Mite Allergies Odactra ... life," said Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research. "The approval ...

  2. Estimation of Fluoride Concentration of Various Citrus and Non-Citrus Fruits Commonly Consumed and Commercially Available in Mathura City

    Directory of Open Access Journals (Sweden)

    Navin Anand Ingle

    2013-01-01

    Full Text Available Background: Since fluoride is available from various sources, the total ingestion of fluoride by a person should be estimated taking into consideration the fluoride consumed from all the sources including fruits. There are very few epidemiological studies carried out associated with fluoride estimation in fruit samplesand especially in the Indian scenario Objective: To estimate and compare the fluoride concentration of different commercially available citrus and non-citrus fruits in Mathura city. Materials & Method: Fifteen different types of fruits commercially available and consumed by people ofMathura City were collected. Out of the 15 fruit samples 5 were citrus fruits and 10 were non-citrus fruits. The fluoride estimation of fruit samples was done at Central Laboratory,Lucknow. Juices of all 15 fruit samples were prepared, from each sample 10 ml of juice was measured and fluoride testing of each sample was carried out by using Orion 4 star -ion electrode analyzer. The collected data was analyzed using the statistical software program SPSS, version 17. Results: The fluoride concentration in citrus fruits ranged from 0.04ppm (Orange to 0.08 ppm (Tomato while in non-citrus fruits it ranged from 0.04ppm (chikoo to 0.18 ppm (Guava. No significant difference was observed between the mean fluoride concentration of citrus and non citrus fruits. Conclusions: Both citrus and non citrus fruits have fluorides. Guava was found to have the maximumamount of fluoridecontent (0.18 ppm among both the citrus and non citrus fruits.

  3. Genetic analysis of seedling resistance to crown rust in five diploid oat (Avena strigosa) accessions.

    Science.gov (United States)

    Cabral, A L; Park, R F

    2016-02-01

    Crown rust, caused by Puccinia coronata Corda f. sp. avenae Eriks., is a serious menace in oats, for which resistance is an effective means of control. Wild diploid oat accessions are a source of novel resistances that first need to be characterised prior to introgression into locally adapted oat cultivars. A genetic analysis of resistance to crown rust was carried out in three diverse diploid oat accessions (CIav6956, CIav9020, PI292226) and two cultivars (Saia and Glabrota) of A. strigosa. A single major gene conditioning resistance to Australian crown rust pathotype (Pt) 0000-2 was identified in each of the three accessions. Allelism tests suggested that these genes are either the same, allelic, or tightly linked with less than 1 % recombination. Similarly, a single gene was identified in Glabrota, and possibly two genes in Saia; both cultivars previously reported to carry two and three crown rust resistance genes, respectively. The identified seedling resistance genes could be deployed in combination with other resistance gene(s) to enhance durability of resistance to crown rust in hexaploid oat. Current diploid and hexaploid linkage maps and molecular anchor markers (simple sequence repeat [SSR] and diversity array technology [DArT] markers) should facilitate their mapping and introgression into hexaploid oat.

  4. Glyphosate inhibits rust diseases in glyphosate-resistant wheat and soybean.

    Science.gov (United States)

    Feng, Paul C C; Baley, G James; Clinton, William P; Bunkers, Greg J; Alibhai, Murtaza F; Paulitz, Timothy C; Kidwell, Kimberlee K

    2005-11-29

    Glyphosate is a broad-spectrum herbicide used for the control of weeds in glyphosate-resistant crops. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase, a key enzyme in the synthesis of aromatic amino acids in plants, fungi, and bacteria. Studies with glyphosate-resistant wheat have shown that glyphosate provided both preventive and curative activities against Puccinia striiformis f. sp. tritici and Puccinia triticina, which cause stripe and leaf rusts, respectively, in wheat. Growth-chamber studies demonstrated wheat rust control at multiple plant growth stages with a glyphosate spray dose typically recommended for weed control. Rust control was absent in formulation controls without glyphosate, dependent on systemic glyphosate concentrations in leaf tissues, and not mediated through induction of four common systemic acquired resistance genes. A field test with endemic stripe rust inoculum confirmed the activities of glyphosate pre- and postinfestation. Preliminary greenhouse studies also demonstrated that application of glyphosate in glyphosate-resistant soybeans suppressed Asian soybean rust, caused by Phakopsora pachyrhizi.

  5. Immobilization of chromate in hyperalkaline waste streams by green rusts and zero-valent iron.

    Science.gov (United States)

    Rogers, Christine M; Burke, Ian T; Ahmed, Imad A M; Shaw, Samuel

    2014-01-01

    Zero-valent iron (ZVI) and green rusts can be used as reductants to convert chromium from soluble, highly toxic Cr(VI) to insoluble Cr(III). This study compared the reduction rates of Cr(VI) by ZVI and two carbonate green rust phases in alkaline/hyperalkaline solutions. Batch experiments were carried out with synthetic chromate solutions at pH 7.7-12.3 and a chromite ore processing residue (COPR) leachate (pH approximately 12.2). Green rust removes chromate from high pH solutions (pH 10-12.5) very rapidly (<400 s). Chromate reduction rates for both green rust phases were consistently higher than for ZVI throughout the pH range studied; the surface area normalized rate constants were two orders of magnitude higher in the COPR leachate solution at pH 12.2. The performances of both green rusts were unaffected by changes in pH. In contrast, ZVI exhibited a marked decline in reduction rate with increasing pH to become almost ineffective above pH12.

  6. Mutualistic interaction between a weevil and a rust fungus, two parasites of the weed Cirsium arvense.

    Science.gov (United States)

    Friedli, Jürg; Bacher, Sven

    2001-12-01

    We present a mutualism between a stem-boring weevil, Apion onopordi Kirby (Coleoptera: Apionidae), and a rust fungus, Puccinia punctiformis (Str.) Röhl. (Uredinales), both parasites of the creeping thistle, Cirsium arvense (L.) Scop. (Asteraceae). Females, but not males, of A. onopordi induced systemic rust infections of thistle shoots in the season after they were attacked by the weevil, indicating that insect oviposition is a crucial stage in pathogen transmission. Adult weevils emerged from systemically infected thistle shoots were heavier than weevils from healthy C. arvense shoots. Heavier females had a higher fecundity and laid larger eggs. The weevil preferred to deposit eggs in systemically rust-infected over healthy thistle shoots, which seemed to be a sub-optimal host. This is to our knowledge the first report of a mutualistic interaction between an herbivorous insect and a biotrophic plant pathogen. The mechanism responsible for the advantage of rust-infected shoots for A. onopordi causes a different outcome in other thistle herbivores, and therefore can not be explained by a general enhancement of nutritional quality in rust-infected tissue. This mutualism likely has evolved from a competitive relationship. Unlike other thistle herbivores A. onopordi seems to be better suited as mutualist for P. punctiformis because of its small impact on the host plant and its feeding niche on plant parts not directly associated with pathogen reproduction.

  7. Polarization Resistance Measurement in Tap Water: The Influence of Rust Electrochemical Activity

    Science.gov (United States)

    Vasyliev, Georgii

    2017-07-01

    Corrosion rate of mild steel in tap water during 4300 h was estimated by LPR and weight-loss methods coupled with OCP measurements. The LPR results were found to be overestimated compared to the weight-loss data within initial 2000 h of exposure. The electrochemical activity of the rust separated from the metal surface was studied by cycling voltammetry using a home-built powder graphite electrode. High redox currents corresponding to the initial 2000 h of exposure were detected. Rust composition was characterized with IR and XRD, and the highest amounts of electrochemically active β- and γ-FeOOH were again detected for the initial 2000 h. Current consumption in rust transformation processes during LPR measurement in the galvanostatic mode accounts for overestimation of the corrosion rate. The time dependence of rust electrochemical activity correlates with OCP variation with time. During initial 2000 h, OCP values are shifted by 50 mV to cathodic side. For the period of a higher rust electrochemical activity, the use of a reduced B is suggested to increase accuracy of LPR technique in tap water.

  8. Application of prediction models of asian soybean rust in two crop seasons, in Londrina, Pr

    Directory of Open Access Journals (Sweden)

    Wagner Teigi Igarashi

    2016-10-01

    Full Text Available Predictive models of Asian soybean rust have been described by researchers to estimate favorable responses to epidemics. The prediction strategies are based on weather data obtained during period when initial symptoms of the disease are observed. Therefore, this study will evaluate the application of two prediction models of Asian soybean rust, and compare the results from two harvest seasons. The experiments were carried out during the 2011/2012 and 2012/2013 seasons in Londrina, PR. “SIGA spore traps” were installed to monitor the presence of Phakopsora pachyrhizi uredospores, and “Electronic trees,” to collect data on weather variables. Following the detection of the first urediniospores, incidence and disease severity were assessed and compared with the predictions made by the models. The model described by Reis et al. (2004 did not indicate conditions favorable for the development of the first rust lesions following the detection of the first urediniospores during the 2011/2012 season. The premonitory symptoms of rust in the first and second harvest seasons were observed only when the model of Reis et al. (2004 indicated SDVPI close to 15 units. The model of Del Ponte et al. (2006b overestimated the final rust severity during the two seasons.

  9. Polarization Resistance Measurement in Tap Water: The Influence of Rust Electrochemical Activity

    Science.gov (United States)

    Vasyliev, Georgii

    2017-08-01

    Corrosion rate of mild steel in tap water during 4300 h was estimated by LPR and weight-loss methods coupled with OCP measurements. The LPR results were found to be overestimated compared to the weight-loss data within initial 2000 h of exposure. The electrochemical activity of the rust separated from the metal surface was studied by cycling voltammetry using a home-built powder graphite electrode. High redox currents corresponding to the initial 2000 h of exposure were detected. Rust composition was characterized with IR and XRD, and the highest amounts of electrochemically active β- and γ-FeOOH were again detected for the initial 2000 h. Current consumption in rust transformation processes during LPR measurement in the galvanostatic mode accounts for overestimation of the corrosion rate. The time dependence of rust electrochemical activity correlates with OCP variation with time. During initial 2000 h, OCP values are shifted by 50 mV to cathodic side. For the period of a higher rust electrochemical activity, the use of a reduced B is suggested to increase accuracy of LPR technique in tap water.

  10. QTL mapping provides evidence for lack of association of the avoidance of leaf rust in Hordeum chilense with stomata density

    NARCIS (Netherlands)

    Vaz Patto, M.C.; Rubiales, D.; Martin, A.; Hernandez, P.; Lindhout, W.H.; Niks, R.E.; Stam, P.

    2003-01-01

    In cereals, rust fungi are among the most harmful pathogens. Breeders usually rely on short-lived hypersensitivity resistance. As an alternative, "avoidance" may be a more durable defence mechanism to protect plants to rust fungi. In Hordeum chilense avoidance is based on extensive wax covering of s

  11. White pine blister rust resistance of 12 western white pine families at three field sites in the Pacific Northwest

    Science.gov (United States)

    Richard A. Sniezko; Robert Danchok; Jim Hamlin; Angelia Kegley; Sally Long; James Mayo

    2012-01-01

    Western white pine (Pinus monticola Douglas ex D. Don) is highly susceptible to the non-native, invasive pathogen Cronartium ribicola, the causative agent of white pine blister rust. The susceptibility of western white pine to blister rust has limited its use in restoration and reforestation throughout much of western North...

  12. White pine blister rust in Korea, Japan and other Asian regions: comparisons and implications for North America

    Science.gov (United States)

    M.-S. Kim; N. B. Klopfenstein; Y. Ota; S. K. Lee; K.-S. Woo; S. Kaneko

    2010-01-01

    This article briefly reviews the history of white pine blister rust, attributed to Cronartium ribicola, and addresses current research and management issues in South Korea, Japan and other regions of eastern Asia (China, Russia and Himalaya). For each region, the distribution, damage, aecial hosts, telial hosts and management of C. ribicola and other blister rust fungi...

  13. Genome-wide association mapping for resistance to leaf and stripe rust in winter-habit hexaploid wheat landraces

    Science.gov (United States)

    Leaf rust, caused by Puccinia triticina (Pt), and stripe rust, caused by P. striiformis f. sp. tritici (Pst), are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst re...

  14. Transformation of hydroxycarbonate green rust into crystalline iron (hydr)oxides: Influences of reaction conditions and underlying mechanisms

    NARCIS (Netherlands)

    Wang, Xiaoming; Liu, Fan; Tan, W.; Feng, Xionghan; Koopal, L.K.

    2013-01-01

    Green rusts (GRs) are found as intermediate products between FeII hydroxides and FeIII oxyhydroxides in various anoxic environments. The transformation of hydroxycarbonate green rust GR1(CO32-) by air oxidation at different conditions and the underlying mechanisms were investigated using X-ray diffr

  15. Detection of Puccinia kuehnii causing sugarcane orange rust with a loop-mediated isothermal amplification-based assay

    Science.gov (United States)

    Puccinia kuehnii is a fungal pathogen that causes orange rust in sugarcane, which is now prevalent in many countries including Florida and Louisiana in the U.S. At the early stage of the disease, it is almost indistinguishable from brown rust, which is caused by another species of Puccinia, viz., P...

  16. Identification of nine pathotype-specific genes conferring resistance to fusiform rust in loblolly pine (Pinus taeda L.)

    Science.gov (United States)

    Henry Amerson; C. Dana Nelson; Thomas L. Kubisiak; E.George Kuhlman; Saul Garcia

    2015-01-01

    Nearly two decades of research on the host-pathogen interaction in fusiform rust of loblolly pine is detailed. Results clearly indicate that pathotype-specific genes in the host interacting with pathogen avirulence cause resistance as defined by the non-gall phenotype under favorable environmental conditions for disease development. In particular, nine fusiform rust...

  17. A small cysteine-rich protein from the Asian soybean rust fungus, Phakopsora pachyrhizi, suppresses plant immunity

    Science.gov (United States)

    The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate pathogen capable of causing explosive disease epidemics that drastically reduce the yield of soybean (Glycine max). Currently, the molecular mechanisms by which P. pachyrhizi and other rust fungi cause disease are poorly understood...

  18. Concerted action of two avirulent spore effectors activates Reaction to Puccinia graminis 1 (Rpg1)-mediated cereal stem rust resistance

    Science.gov (United States)

    The barley stem rust resistance gene Reaction to Puccinia graminis 1 (Rpg1), encoding a receptor-like kinase, confers durable resistance to the stem rust pathogen Puccinia graminis f. sp. tritici. The fungal urediniospores form adhesion structures with the leaf epidermal cells within 1 h of inocula...

  19. Genetic mapping of rust resistance genes in confection sunflower line HA-R6 and oilseed line RHA 397

    Science.gov (United States)

    Few widely effective resistance sources to sunflower rust, incited by Puccinia helianthi Schwein., have been identified in confection sunflower (Helianthus annuus L.). The USDA inbred line HA-R6 is one of the few confection sunflower lines resistant to rust. A previous allelism test indicated that r...

  20. The impact of pesticides on apple mite communities

    OpenAIRE

    Ahmad, Shakeel

    2013-01-01

    Laboratory, field and semi-field experiments have been carried out on the predatory mites Kampimodromus aberrans, Amblyseius andersoni, Typhlodromus pyri and Phytoseius finitimus in order to optimize biological control strategies against phytophagous mites in apple orchards. The first experiment concerned the augmentative releases of K. aberrans in organic and conventional apple orchards. The most frequent insecticides used in organic orchards were pyrethrins and spinosad, whereas neonicotino...

  1. PCR analysis for Wolbachia in human and canine Demodex mites.

    Science.gov (United States)

    Borgo, Sibylle N; Sattler, Elke C; Hogardt, Michael; Adler, Kristin; Plewig, Gerd

    2009-10-01

    In many skin diseases such as Demodex folliculitis, rosacea- or steroid-induced rosacea Demodex mites are present in abundance and are at least partially held responsible for causing these disorders. Although it is known that these diseases respond well to tetracyclines, it is unclear if this is due to the antiinflammatory effects of the antibiotics or to an antibacterial effect on so far unknown bacteria within the Demodex mites. As in filariasis, where the response to doxycycline can be explained by the presence of Wolbachia within the filarial nematodes, this study was performed to see whether Wolbachia also use Demodex mites as their hosts. Human and canine Demodex mite samples were taken by skin scrapings and tested by PCR for the presence of Wolbachia DNA. Wolbachia pipientis DNA was used as positive control. In none of the DNA extracts, Wolbachia were detected showing no evidence for the presence of these bacteria in Demodex mites. The response of Demodex aggravated or Demodex caused diseases to tetracyclines seems not to be due to the presence of Wolbachia in Demodex mites in contrast to the results seen in filariasis.

  2. Evolution of host range in the follicle mite Demodex kutzeri.

    Science.gov (United States)

    Palopoli, Michael F; Tra, VAN; Matoin, Kassey; Mac, Phuong D

    2016-11-29

    The sequences of four mitochondrial genes were determined for Demodex mites isolated from two distantly related species within the family Cervidae, and identified morphologically as belonging to the species Demodex kutzeri. The sequences were used to test the hypothesis that Demodex are strictly host-specific, and hence cospeciate with their hosts: (1) The estimated divergence time between mites found on elk vs humans agreed closely with a previous estimate of the time that these host species last shared a common ancestor, suggesting cospeciation of mites and hosts, at least over long evolutionary timescales. (2) The extremely low levels of sequence divergence between the mites found on elk vs mule deer hosts indicated that these mites belong to the same species, which suggests that Demodex are able to move across host species boundaries over shorter timescales. Together, the results are consistent with the model that Demodex mites are not strict host-specialists, but instead lose the ability to move between host lineages gradually.

  3. New Wolbachia supergroups detected in quill mites (Acari: Syringophilidae).

    Science.gov (United States)

    Glowska, Eliza; Dragun-Damian, Anna; Dabert, Miroslawa; Gerth, Michael

    2015-03-01

    Wolbachia is the most abundant intracellular bacterial genus infecting a wide range of arthropods and filarial nematodes. Wolbachia have evolved parasitic, mutualistic and commensal relationships with their hosts but in arthropods generally act as reproductive parasites, inducing a wide range of phenotypic effects such as cytoplasmic incompatibility, parthenogenesis, feminization and male-killing. Up to now, the genus has been divided into 14 supergroups successively named A-O. Here, we describe two new Wolbachia supergroups from syringophilid mites (Acari: Cheyletoidea). These obligatory ectoparasites of birds inhabit the quills of feathers in many avian groups. The species of this family reproduce in a haplodiploid mode sensu arrhenotoky and are usually strongly female-biased. Based on the sequences of four protein-coding genes (ftsZ, gltA and groEL and coxA) and the 16S rRNA we identified strains of three Wolbachia supergroups (F and two distinct, yet undescribed ones) in five quill mite species. Our results suggest that in some cases the distribution of the bacteria can be better correlated with the mite's bird host rather than with mite taxonomy as such. The discovery of two new Wolbachia supergroups not only broadens the knowledge of the diversity of this bacterium but also raises questions about potential effects induced in quill mites and transmission mechanisms of the endosymbionts in this peculiar bacteria-quill mite-bird system.

  4. Age and reproductive status of adult Varroa mites affect grooming success of honey bees.

    Science.gov (United States)

    Kirrane, Maria J; de Guzman, Lilia I; Rinderer, Thomas E; Frake, Amanda M; Wagnitz, Jeremy; Whelan, Pádraig M

    2012-12-01

    This study evaluated for the first time the grooming response of honey bees to Varroa mites of different ages and reproductive statuses in the laboratory. Plastic cages containing a section of dark comb and about 200 bees were inoculated with groups of four classes of mites: gravid, phoretic foundresses, phoretic daughters and a combination of gravid and phoretic foundress mites. Each cage received 20 mites belonging to one of these classes. Our results showed that, 1 day after mite inoculation, phoretic daughter mites were the most prone to grooming by honey bees with an average mite drop of 49.8 ± 2.6 %. The lowest mite drop was recorded for bees inoculated with phoretic foundresses (30.3 ± 3.6 %) but was comparable to bees inoculated with gravid mites (31.8 ± 3.8 %) and the combination of gravid and phoretic foundress mites (34.2 ± 3.2 %). No differences among mite types were detected during the second and third days of observation. Regardless of mite type, the highest mite drop was recorded on the first day (35 ± 2.1 %) compared to the drop for any subsequent day (grooming behaviour may increase our insight into the importance of grooming in mite resistance.

  5. Anticancer Activity of Key Lime, Citrus aurantifolia

    OpenAIRE

    Nithithep Narang; Wannee Jiraungkoorskul

    2016-01-01

    Citrus aurantifolia (family: Rutaceae) is mainly used in daily consumption, in many cultural cuisines, and in juice production. It is widely used because of its antibacterial, anticancer, antidiabetic, antifungal, anti-hypertensive, anti-inflammation, anti-lipidemia, and antioxidant properties; moreover, it can protect heart, liver, bone, and prevent urinary diseases. Its secondary metabolites are alkaloids, carotenoids, coumarins, essential oils, flavonoids, phenolic acids, and triterpenoids...

  6. Effectiveness of Citrus Fruits on Helicobacter pylori

    Science.gov (United States)

    2017-01-01

    It is known that Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer, and gastric carcinoma. Due to the increased side effects of the treatment regimens and the development of antimicrobial resistance, a number of natural compounds have been tested as potential alternatives. In this review, we will examine the current knowledge on the effect of Citrus fruits and their derivatives against H. pylori, highlighting the remaining outstanding questions on the development of novel therapeutic strategies. PMID:28408943

  7. Huanglongbing Resistance and Tolerance in Citrus

    OpenAIRE

    Stover, E.; McCollum, G.; Driggers, R.; Duan, Y; Shatters, Jr., R. G.; Ritenour, M.; Hall, D.G.; J. Chaparro

    2014-01-01

    Huanglongbing (HLB) is severely impacting Florida citrus. Productivity declines in many HLB-affected genotypes, often with greatly thinned canopies. Fruit size and quality are often adversely affected as the disease advances. HLB was assessed in diverse cultivars in commercial groves with high HLB-incidence. ‘Temple’ had the lowest HLB symptoms and Liberibacter (Las) titer, while ‘Murcott’ and ‘Minneola’ had the highest. The USDA Ft. Pierce, FL farm is managed to reveal genotype responses to ...

  8. Modeling huanglongbing transmission within a citrus tree.

    Science.gov (United States)

    Chiyaka, Christinah; Singer, Burton H; Halbert, Susan E; Morris, J Glenn; van Bruggen, Ariena H C

    2012-07-24

    The citrus disease huanglongbing (HLB), associated with an uncultured bacterial pathogen, is threatening the citrus industry worldwide. A mathematical model of the transmission of HLB between its psyllid vector and citrus host has been developed to characterize the dynamics of the vector and disease development, focusing on the spread of the pathogen from flush to flush (a newly developing cluster of very young leaves on the expanding terminal end of a shoot) within a tree. This approach differs from that of prior models for vector-transmitted plant diseases where the entire plant is the unit of analysis. Dynamics of vector and host populations are simulated realistically as the flush population approaches complete infection. Model analysis indicates that vector activity is essential for initial infection but is not necessary for continued infection because infection can occur from flush to flush through internal movement in the tree. Flush production, within-tree spread, and latent period are the most important parameters influencing HLB development. The model shows that the effect of spraying of psyllids depends on time of initial spraying, frequency, and efficacy of the insecticides. Similarly, effects of removal of symptomatic flush depend on the frequency of removal and the time of initiation of this practice since the start of the epidemic. Within-tree resistance to spread, possibly affected by inherent or induced resistance, is a major factor affecting epidemic development, supporting the notion that alternate routes of transmission besides that by the vector can be important for epidemic development.

  9. Polyembryony in non-apomictic citrus genotypes

    Science.gov (United States)

    Aleza, Pablo; Juárez, José; Ollitrault, Patrick; Navarro, Luis

    2010-01-01

    Background and Aims Adventitious embryony from nucellar cells is the mechanism leading to apomixis in Citrus sp. However, singular cases of polyembryony have been reported in non-apomictic genotypes as a consequence of 2x × 4x hybridizations and in vitro culture of isolated nucelli. The origin of the plants arising from the aforementioned processes remains unclear. Methods The genetic structure (ploidy and allelic constitution with microsatellite markers) of plants obtained from polyembryonic seeds arising from 2x × 4x sexual hybridizations and those regenerated from nucellus culture in vitro was systematically analysed in different non-apomictic citrus genotypes. Histological studies were also conducted to try to identify the initiation process underlying polyembryony. Key Results All plants obtained from the same undeveloped seed in 2x × 4x hybridizations resulted from cleavage of the original zygotic embryo. Also, the plants obtained from in vitro nucellus culture were recovered by somatic embryogenesis from cells that shared the same genotype as the zygotic embryos of the same seed. Conclusions It appears that in non-apomictic citrus genotypes, proembryos or embryogenic cells are formed by cleavage of the zygotic embryos and that the development of these adventitious embryos, normally hampered, can take place in vivo or in vitro as a result of two different mechanisms that prevent the dominance of the initial zygotic embryo. PMID:20675656

  10. Citrus aurantium blossom and preoperative anxiety.

    Science.gov (United States)

    Akhlaghi, Mahmood; Shabanian, Gholamreza; Rafieian-Kopaei, Mahmoud; Parvin, Neda; Saadat, Mitra; Akhlaghi, Mohsen

    2011-01-01

    Reducing anxiety is very important before operation. Preoperative visit and use of premedication are popular methods to achieve this goal, but the role of anxiolytic premedication remains unclear and postoperative side-effects may result from routine premedication. Citrus aurantium is used as an alternative medicine in some countries to treat anxiety, and recently the anxiolytic role of this medicinal plant was established in an animal model study. The aim of this study was to assess the anxiolytic effect of Citrus aurantium blossomon preoperative anxiety. We studied 60 ASA I patients undergoing minor operation. In a randomized double-blind design, two groups of 30 patients received one of the following oral premedication two hours before induction of anesthesia: 1) Citrus aurantium blossom distillate 1mL.kg(-1) (C-group); 2) Saline solution 1mL.kg(-1) as placebo (P-group). Anxiety was measured before and after premedication using the Spielberger state-trait anxiety inventory (STAI-state) and the Amsterdam preoperative anxiety and information scale (APAIS) before operation. After premedication, both the STAI-state and the APAIS scales were decreased in C-group (ppreoperative anxiety before minor operation. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

  11. Sonora exploratory study for the detection of wheat-leaf rust

    Science.gov (United States)

    Payne, R. W. (Principal Investigator)

    1980-01-01

    The applicability of LANDSAT remote sensing technology to the detection of a wheat-leaf-rust epidemic in Sonora, Mexico, during 1977 was investigated. LANDSAT data acquired during crop years 1975-76 and 1976-77 were clustered, classified, and analyzed in order to detect agricultural changes. Analysis of 1977 data indicates a significant proportion of the identified wheat is stressed (potentially rust-infected). Additional analyses show a significant increase in fallowing during the year, as well as a substantial decrease in reservoir levels in the Sonora agricultural region. Ground observations are required to substantiate these analyses. The possibility exists that heat-rust is not LANDSAT detectable and that the clusters identified as containing stressed signatures represent different varieties of wheat or perhaps nonwheat crops.

  12. Reflexion M\\"ossbauer analysis of the in situ oxidation products hydroxycarbonate green rust

    CERN Document Server

    Naille, Sebastien; Louber, Didier; Jean, Paul Moulin; Ruby, Christian; 10.1088/1742-6596/217/1/012084

    2010-01-01

    The purpose of this study is to determine the nature of the oxidation products of FeII-III hydroxycarbonate FeII4FeIII2(OH)12CO3~3H2O (green rust GR(CO32-)) by using the miniaturised M\\"ossbauer spectrometer MIMOS II. Two M\\"ossbauer measurements methods are used: method (i) with green rust pastes coated with glycerol and spread into Plexiglas sample holders, and method (ii) with green rust pastes in the same sample holders but introduced into a gas-tight cell with a beryllium window under a continuous nitrogen flow. Method (ii) allows us to follow the continuous deprotonation of GR(CO32-) into the fully ferric deprotonated form FeIII6O4(OH)8CO3~3H2O by adding the correct amount of H2O2, without any further oxidation or degradation of the samples.

  13. Genes for resistance to stripe rust on chromosome 2B and their application in wheat breeding

    Institute of Scientific and Technical Information of China (English)

    Peigao Luo; Xueyun Hu; Huaiyu Zhang; Zhenglong Ren

    2009-01-01

    Stripe rust,caused by Puccinia striiformis f.sp.tritici,is one of the most damaging diseases of wheat worldwide.Growing resistant cultivars is the most economic and environmental friendly way to control the disease.There are many resistance genes to stripe rust located on wheat chromosome 2B.Here,we propose a strategy to construct the recombinant wheat chromosome 2B with multiple resistances to stripe rust by making crosses between wheat lines or cultivars carrying Yr genes and using marker-assisted selection,based on the reported information about resistance spectrum,chromosomal location,and linked markers of the genes.Pyramiding the resistance genes on 2B would afford a valuable strategy to control the disease by cultivating varieties with durable resistance.The possibility,efficiency,and prospect of the suggested strategy are reviewed in the paper.

  14. Effect of Nigerian citrus (Citrus sinensis Osbeck) honey on ethanol metabolism.

    Science.gov (United States)

    Onyesom, I

    2004-12-01

    The effect of Nigerian citrus (Citrus sinensis Osbeck) honey on ethanol metabolism was tested using 45 consenting individuals in apparent good health and between the ages of 25 and 35 years. The subjects were moderate social drinkers matched in terms of body weight and build. The results obtained showed that on average, honey significantly (p 0.05) reduced the degree of intoxication by 9%. Honey could be a promising anti-intoxicating agent, but its long-term biochemical evaluation, possibly as a complement in the management of alcohol intoxication, deserves further study.

  15. Rust resistance in Arabic Coffee cultivars in northern Paraná

    Directory of Open Access Journals (Sweden)

    Leandro Del Grossi

    2013-02-01

    Full Text Available The objective of the study was to evaluate the resistance to rust in coffee cultivars developed by research institutes of Brazil in Paraná state. Resistance to the local leaf rust races was assessed in high disease intensity field conditions at Londrina and Congonhinhas in 2009 and 2010.The cultivars were developed by the EPAMIG/UFV, IAPAR, IAC and MAPA/Procafé. The resistant standard 'IAPAR 59' and the susceptible standards Catuaí Vermelho IAC 144' and 'Bourbon Amarelo' were used. A randomized block design with three replications and plots with 10 plants was used. A scale from 1 to 5 based on the rust intensity was used to evaluate the resistance. The Catiguá MG 1, Catiguá MG 2, IAPAR 59, IPR 98, IPR 104, Palma II, Paraíso H-419-10-6-2-5-1, Paraíso H-419-10-6-2-10-1, Paraíso H-419-10-6-2-12-1, Pau Brasil MG 1 and Sacramento MG 1 cultivars presented complete resistance to rust at Londrina and Congonhinhas. The cultivars derived from the Catucaí germplasm were susceptible or showed different levels of partial resistance. Partial resistance to the rust was observed in several coffees derived from "Hibrido de Timor". 'Acauã' and 'Obatã IAC 1669-20' presented complete resistance at Londrina, but at Congonhinhas, they were partially resistant, indicating that different rust races have occurred at these two locations.

  16. Efficacy of plant extracts in controlling wheat leaf rust disease caused by Puccinia triticina

    Directory of Open Access Journals (Sweden)

    Yasser M. Shabana

    2017-03-01

    Full Text Available The efficacy of eight plant extracts (garlic, clove, garden quinine, Brazilian pepper, anthi mandhaari, black cumin, white cedar and neem in controlling leaf rust disease of wheat was investigated in vitro and in vivo. In vitro, all treatments inhibited spore germination by more than 93%. Neem extract recorded 98.99% inhibition of spore germination with no significant difference from the fungicide Sumi-8 (100%. Under greenhouse conditions, seed soaking application in neem extract (at concentration of 2 ml/L resulted in 36.82% reduction in the number of pustules/leaf compared with the untreated control. Foliar spraying of plant extracts on wheat seedlings decreased the number of pustules/leaf. Foliar spraying of plant extracts four days after inoculation led to the highest resistance response of wheat plants against leaf rust pathogen. Spray application of wheat seedlings with neem, clove and garden quinine extracts, four days after inoculation with leaf rust pathogen completely prevented rust development (100% disease control and was comparable with the fungicide Sumi-8. Foliar spray application of wheat plants at mature stage with all plant extracts has significantly reduced the leaf rust infection (average coefficient of infection, ACI compared with the untreated control and neem was the most effective treatment. This was reflected on grain yield components, whereas the 1000-kernel weight and the test weight were improved whether under one- or two-spray applications, with two-spray application being more effective in this regard. Thus, it could be concluded that plant extracts may be useful to control leaf rust disease in Egypt as a safe alternative option to chemical fungicides.

  17. Citrus essential oils: Extraction, authentication and application in food preservation.

    Science.gov (United States)

    Mahato, Neelima; Sharma, Kavita; Koteswararao, Rakoti; Sinha, Mukty; Baral, Ek Raj; Cho, Moo Hwan

    2017-09-28

    Citrus EOs is an economic, eco-friendly and natural alternatives to chemical preservatives and other synthetic antioxidants, such as sodium nitrites, nitrates or benzoates, commonly utilized in food preservation. Citrus based EOs is obtained mainly from the peels of citrus fruits which are largely discarded as wastes and cause environmental problems. The extraction of citrus oils from the waste peels not only saves environment but can be used in various applications including food preservation. The present article presents elaborated viewpoints on the nature and chemical composition of different EOs present in main citrus varieties widely grown across the globe; extraction, characterization and authentication techniques/methods of the citrus EOs; and reviews the recent advances in the application of citrus EOs for the preservation of fruits, vegetables, meat, fish and processed food stuffs. The probable reaction mechanism of the EOs based thin films formation with biodegradable polymers is presented. Other formulation, viz., EOs microencapsulation incorporating biodegradable polymers, nanoemulsion coatings, spray applications and antibacterial action mechanism of the active compounds present in the EOs have been elaborated. Extensive research is required on overcoming the challenges regarding allergies and obtaining safer dosage limits. Shift towards greener technologies indicate optimistic future towards safer utilization of citrus based EOs in food preservation.

  18. Developing cryotherapy to eliminate graft-transmissible pathogens in citrus

    Science.gov (United States)

    This article summarizes research being conducted as part of a project funded by the California Citrus Research Board to develop cryotherapy (freezing buds in liquid nitrogen, and then recovering them) as a viable method for elimination of graft transmissible pathogens from Citrus. There are current...

  19. 21 CFR 74.302 - Citrus Red No. 2.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color...

  20. Characterizing the citrus cultivar Carrizo genome through 454 shotgun sequencing.

    Science.gov (United States)

    Belknap, William R; Wang, Yi; Huo, Naxin; Wu, Jiajie; Rockhold, David R; Gu, Yong Q; Stover, Ed

    2011-12-01

    The citrus cultivar Carrizo is the single most important rootstock to the US citrus industry and has resistance or tolerance to a number of major citrus diseases, including citrus tristeza virus, foot rot, and Huanglongbing (HLB, citrus greening). A Carrizo genomic sequence database providing approximately 3.5×genome coverage (haploid genome size approximately 367 Mb) was populated through 454 GS FLX shotgun sequencing. Analysis of the repetitive DNA fraction indicated a total interspersed repeat fraction of 36.5%. Assembly and characterization of abundant citrus Ty3/gypsy elements revealed a novel type of element containing open reading frames encoding a viral RNA-silencing suppressor protein (RNA binding protein, rbp) and a plant cytokinin riboside 5′-monophosphate phosphoribohydrolase-related protein (LONELY GUY, log). Similar gypsy elements were identified in the Populus trichocarpa genome. Gene-coding region analysis indicated that 24.4% of the nonrepetitive reads contained genic regions. The depth of genome coverage was sufficient to allow accurate assembly of constituent genes, including a putative phloem-expressed gene. The development of the Carrizo database (http://citrus.pw.usda.gov/) will contribute to characterization of agronomically significant loci and provide a publicly available genomic resource to the citrus research community.

  1. Citrus Tristeza Virus on the Island of Crete

    DEFF Research Database (Denmark)

    Shegani, M.; Tsikou, D.; Velimirovic, A.

    2012-01-01

    Over a period of two years, more than 5,000 citrus trees were tested for the presence of Citrus tristeza virus (CTV) on the island of Crete, resulting in thirty eight positives. Comparisons of the relative transcript levels of CTV p23, coat protein (CP), polymerase (POL) and an intergenic (POL/p33...

  2. Development of sparse-seeded mutant kinnow (Citrus reticulata ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... The mutant was put to the conventional propagation up to mV5, for confirmation of the continuity of ... techniques with fruits such as citrus, grape (Vitis vinifera ... irradiated bud scions were grafted onto Citrus jambhiri rootstock,.

  3. Water and nitrogen use efficiencies in citrus production

    NARCIS (Netherlands)

    Qin, Wei; Assinck, F.B.T.; Heinen, Marius; Oenema, Oene

    2016-01-01

    Water and nitrogen (N) are two key limiting factors for citrus production. Reported effects of water and N inputs on citrus yield, water use efficiency (WUE) and N use efficiency (NUE) vary greatly, mainly due to differences in cultivars, tree age, climate, soil types, and water and N input level

  4. Behavioral assay on Asian citrus psyllid attraction to orange jasmine

    Science.gov (United States)

    The Asian citrus psyllid (ACP) is an important pest because it transmits a bacterium putatively responsible for huanglongbing, a devastating citrus disease. Research on ACP chemical ecology is of interest with respect to identifying attractants and repellents for managing the psyllid. We report on a...

  5. Changes in anthocyanin production during domestication of citrus

    Science.gov (United States)

    Mandarin (C. reticulata), citron (C. medica) and pummelo (C. maxima) are imortant fruit species of the genus Citrus and parents of the interspecific hybrids that constitute the most familiar commercial varities of citrus: sweet orange, sour orange, clementine, lemon lme and grapefruit. Citron and it...

  6. Utilization of founder lines for improved Citrus biotechnology via RMCE

    Science.gov (United States)

    On October 1st 2011 the CRB chose to fund a unique research project, the development of citrus cultivars specifically for genetic engineering (GE). The objective of this research was to develop GE citrus ‘Founder Lines’ containing DNA sequences that will allow the precise insertion of genes for de...

  7. Citrus tristeza virus-host interactions

    Science.gov (United States)

    Dawson, W. O.; Garnsey, S. M.; Tatineni, S.; Folimonova, S. Y.; Harper, S. J.; Gowda, S.

    2013-01-01

    Citrus tristeza virus (CTV) is a phloem-limited virus whose natural host range is restricted to citrus and related species. Although the virus has killed millions of trees, almost destroying whole industries, and continually limits production in many citrus growing areas, most isolates are mild or symptomless in most of their host range. There is little understanding of how the virus causes severe disease in some citrus and none in others. Movement and distribution of CTV differs considerably from that of well-studied viruses of herbaceous plants where movement occurs largely through adjacent cells. In contrast, CTV systemically infects plants mainly by long-distance movement with only limited cell-to-cell movement. The virus is transported through sieve elements and occasionally enters an adjacent companion or phloem parenchyma cell where virus replication occurs. In some plants this is followed by cell-to-cell movement into only a small cluster of adjacent cells, while in others there is no cell-to-cell movement. Different proportions of cells adjacent to sieve elements become infected in different plant species. This appears to be related to how well viral gene products interact with specific hosts. CTV has three genes (p33, p18, and p13) that are not necessary for infection of most of its hosts, but are needed in different combinations for infection of certain citrus species. These genes apparently were acquired by the virus to extend its host range. Some specific viral gene products have been implicated in symptom induction. Remarkably, the deletion of these genes from the virus genome can induce large increases in stem pitting (SP) symptoms. The p23 gene, which is a suppressor of RNA silencing and a regulator of viral RNA synthesis, has been shown to be the cause of seedling yellows (SY) symptoms in sour orange. Most isolates of CTV in nature are populations of different strains of CTV. The next frontier of CTV biology is the understanding how the virus

  8. Transferability of SSR markers from related Uredinales species to the coffee rust Hemileia vastatrix.

    Science.gov (United States)

    Cristancho, M; Escobar, C

    2008-10-28

    The aim of the present research was to test the transferability of simple sequence repeat (SSR) markers developed in two Uredinales species to Hemileia vastatrix, coffee rust. The development of efficient techniques for the identification of H. vastatrix isolates is imperative, given the continuous development of new races. The transferability of 25 SSR markers developed in the related Uredinales species Puccinia coronata f. sp lolli and Melampsora linii to H. vastatrix was tested. A low level of transferability of SSRs was detected, and only 4 potential markers that can be used to fingerprint the coffee rust races were identified.

  9. Potential impact of climate change on coffee rust over Mexico and Central America

    Science.gov (United States)

    Calderon-Ezquerro, Maria del Carmen; Martinez-Lopez, Benjamin; Cabos Narvaez, William David; Sein, Dmitry

    2017-04-01

    In this work, some meteorological variables from a regional climate model are used to characterize the dispersion of coffee rust (a fungal disease) from Central America to Mexico, during the 20 Century. The climate model consists of the regional atmosphere model REMO coupled to the MPIOM global ocean model with increased resolution in the Atlantic Ocean. Lateral atmospheric and upper oceanic boundary conditions outside the coupled domain were prescribed using both ERA-40 and ERA-Interim reanalysis data. In addition to the historical simulation, a projection of the evolution of the coffee rust for the 21 Century was obtained from a REMO run using MPIESM data for the lateral forcing.

  10. Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages

    DEFF Research Database (Denmark)

    Ali, Sajid; Rodriguez Algaba, Julian; Thach, Tine

    2017-01-01

    We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed that these epide......We investigated whether the recent worldwide epidemics of wheat yellow rust were driven by races of few clonal lineage(s) or populations of divergent races. Race phenotyping of 887 genetically diverse Puccinia striiformis isolates sampled in 35 countries during 2009–2015 revealed...

  11. Mini Review: Innovation technology cultivaion of Citrus Tangerines Borneo Prima in East Kalimantan

    Directory of Open Access Journals (Sweden)

    AFRILIA TRI WIDYAWATI

    2017-03-01

    Full Text Available Abstract. Widyawati AT, Nurbani. 2017. Mini Review: Innovation technology cultivaion of Citrus Tangerines Borneo Prima in East Kalimantan. Pros Sem Nas Masy Biodiv Indon 3: 127-131. The demand for high-value commodities such as oranges continues to increase every year. One of the qualities of orange that can not be met by domestic manufacturers is the color of a citrus peel. Most consumers like citrus orange, like mandarin oranges and other citrus imports. Efforts to reduce the national citrus imports is to improve the productivity and quality of citrus orange in Indonesia. Citrus Tangerines Borneo Prima is one of the featured horticultural commodities in East Kalimantan, which has the advantage of being low lying tangerine with orange rind. It Is indispensable citrus cultivation technique is good and right, so that the citrus plant can develop optimally so that later can produce citrus fruit both in quality and quantity.

  12. Dissipation and residue of forchlorfenuron in citrus fruits.

    Science.gov (United States)

    Chen, Weijun; Jiao, Bining; Su, Xuesu; Zhao, Qiyang; Qin, Dongmei; Wang, Chengqiu

    2013-06-01

    Field trials were carried out in three provinces of China to study the dissipation and residue of forchlorfenuron in citrus fruits. The results had shown that the degradation rate of forchlorfenuron in citrus fruits followed the first-order kinetics equation C = A∙eBt. The half-lives of forchlorfenuron were 15.8-23.0 days, the final residues of forchlorfenuron in pulp were all ≤0.002 mg/kg, and most of the residues were concentrated in the peel. The risk assessment revealed that no significant potential health risk would be induced by forchlorfenuron in citrus fruits. Therefore, it could be safe to apply forchlorfenuron in citrus fruits, and the results of this study could also be regarded as a reference to the setting of maximum residue limit for forchlorfenuron in citrus fruits in China.

  13. Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement.

    Science.gov (United States)

    Omar, Ahmad A; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W

    2016-01-01

    The genus Citrus contains numerous fresh and processed fruit cultivars that are economically important worldwide. New cultivars are needed to battle industry threatening diseases and to create new marketing opportunities. Citrus improvement by conventional methods alone has many limitations that can be overcome by applications of emerging biotechnologies, generally requiring cell to plant regeneration. Many citrus genotypes are amenable to somatic embryogenesis, which became a key regeneration pathway in many experimental approaches to cultivar improvement. This chapter provides a brief history of plant somatic embryogenesis with focus on citrus, followed by a discussion of proven applications in biotechnology-facilitated citrus improvement techniques, such as somatic hybridization, somatic cybridization, genetic transformation, and the exploitation of somaclonal variation. Finally, two important new protocols that feature plant regeneration via somatic embryogenesis are provided: protoplast transformation and Agrobacterium-mediated transformation of embryogenic cell suspension cultures.

  14. Digestion kinetics of carbohydrate fractions of citrus by-products.

    Science.gov (United States)

    Lashkari, Saman; Taghizadeh, Akbar

    2015-01-01

    The present experiment was carried out to determine the digestion kinetics of carbohydrate fractions of citrus by-products. Grapefruit pulp (GP), lemon pulp (LE), lime pulp (LI) and orange pulp (OP) were the test feed. Digestion kinetic of whole citrus by-products and neutral detergent fiber (NDF) fraction and acid detergent fiber (ADF) fractions of citrus by-products were measured using the in vitro gas production technique. Fermentation kinetics of the neutral detergent soluble carbohydrates (NDSC) fraction and hemicelluloses were calculated using a curve subtraction. The fermentation rate of whole was the highest for the LE (p fractions. There was no significant difference among potential gas production (A) volumes of whole test feeds (p fractions of citrus by-products have high potential for degradability. It could also be concluded that carbohydrate fractions of citrus by-products have remarkable difference in digestion kinetics and digestive behavior.

  15. Mite species inhabiting commercial bumblebee (Bombus terrestris) nests in Polish greenhouses.

    Science.gov (United States)

    Rożej, Elżbieta; Witaliński, Wojciech; Szentgyörgyi, Hajnalka; Wantuch, Marta; Moroń, Dawid; Woyciechowski, Michal

    2012-03-01

    Nests of social insects are usually inhabited by various mite species that feed on pollen, other micro-arthropods or are parasitic. Well-known negative effects of worldwide economic importance are caused by mites parasitizing honeybee colonies. Lately, attention has focused on the endoparasitic mite Locustacarus buchneri that has been found in commercial bumblebees. However, little is known of other mites associated with commercial bumblebee nests. Transportation of commercial bumblebee colonies with unwanted residents may introduce foreign mite species to new localities. In this study, we assessed the prevalence and species composition of mites associated with commercial bumblebee nests and determined if the mites are foreign species for Poland and for Europe. The study was conducted on 37 commercial bumblebee nests from two companies (Dutch and Israeli), originating from two greenhouses in southern Poland, and on 20 commercial bumblebee colonies obtained directly from suppliers. The species composition and abundance of mites inhabiting commercial bumblebee nests were determined. Seven mite species from three families were found in nests after greenhouse exploitation. The predominant mite species was Tyrophagus putrescentiae (Acaridae) that was a 100-fold more numerous than representatives of the family Laelapidae (Hypoaspis marginepilosa, H. hyatti, H. bombicolens). Representatives of Parasitidae (Parasitellus fucorum, P. crinitus, P. ignotus) were least numerous. All identified mite species are common throughout Europe, foreign species were not found. Mites were not detected in nests obtained directly from suppliers. We conclude that probably bumblebee nests are invaded by local mite species during greenhouse exploitation.

  16. Immunotherapy with the storage mite lepidoglyphus destructor.

    Science.gov (United States)

    Armentia-Medina, A; Tapias, J A; Martín, J F; Ventas, P; Fernández, A

    1995-01-01

    We carried out a double-blind clinical trial of immunotherapy on 35 patients sensitized to the storage mite Lepidoglyphus destructor (Ld). Before and after 12 months of specific hyposensitization (Abelló Lab., Spain) we performed in vivo (skin tests with Ld, methacholine and challenge tests), and in vitro tests (specific IgE, IgG, IgG1 and IgG4 to Ld and specific IgE, IgG, IgG1 and IgG4 to their major allergen Lep dI). We also monitored the efficacy and safety of the immunotherapy with clinical and analytical controls (symptoms and medication score, detection of immune complexes). After therapy we found a significant decrease in specific skin reactivity, dose of positive challenge tests, and hyperresponsiveness to methacholine. Sputum eosinophilia decreased. Specific IgE to Ld was increased and we also observed an increase in specific IgG1 and IgG4 to Ld and Lep DI. The placebo group showed no changes in these variables. There were no severe secondary reactions after treatment with the extract. Patients-self-evaluation was favourable and their labour absence decreased. No development of circulating immune complexes was associated with this immunotherapy.

  17. Citrus leaf blotch virus invades meristematic regions in Nicotiana benthamiana and citrus.

    Science.gov (United States)

    Agüero, Jesús; Vives, María Carmen; Velázquez, Karelia; Ruiz-Ruiz, Susana; Juárez, Jose; Navarro, Luis; Moreno, Pedro; Guerri, José

    2013-08-01

    To invade systemically host plants, viruses need to replicate in the infected cells, spread to neighbouring cells through plasmodesmata and move to distal parts of the plant via sieve tubes to start new infection foci. To monitor the infection of Nicotiana benthamiana plants by Citrus leaf blotch virus (CLBV), leaves were agroinoculated with an infectious cDNA clone of the CLBV genomic RNA expressing green fluorescent protein (GFP) under the transcriptional control of a duplicate promoter of the coat protein subgenomic RNA. Fluorescent spots first appeared in agroinfiltrated leaves 11-12 days after infiltration, indicating CLBV replication. Then, after entering the phloem vascular system, CLBV was unloaded in the upper parts of the plant and invaded all tissues, including flower organs and meristems. GFP fluorescence was not visible in citrus plants infected with CLBV-GFP. Therefore, to detect CLBV in meristematic regions, Mexican lime (Citrus aurantifolia) plants were graft inoculated with CLBV, with Citrus tristeza virus (CTV), a virus readily eliminated by shoot-tip grafting in vitro, or with both simultaneously. Although CLBV was detected by hybridization and real-time reverse transcription-polymerase chain reaction (RT-PCR) in 0.2-mm shoot tips in all CLBV-inoculated plants, CTV was not detected. These results explain the difficulty in eliminating CLBV by shoot-tip grafting in vitro. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  18. 77 FR 59709 - Citrus Greening and Asian Citrus Psyllid; Quarantine and Interstate Movement Regulations

    Science.gov (United States)

    2012-10-01

    ...: Effective October 31, 2012. FOR FURTHER INFORMATION CONTACT: Ms. Lynn Evans-Goldner, National Program... Huanglongbing disease of citrus by the international taxonomic community. We are amending the definition to... issued under Sec. 204, Title II, Public Law 106-113, 113 Stat. 1501A-293; sections 301.75-15 and...

  19. 76 FR 78228 - Notice of Request for Extension of Approval of an Information Collection; Citrus Greening and...

    Science.gov (United States)

    2011-12-16

    ... regulations to implement the PPA. Citrus greening, also known as Huanglongbing disease of citrus, is considered to be one of the most serious citrus diseases in the world. Citrus greening is a bacterial disease... the fruit, and can kill trees. Once infected, there is no cure for a tree with citrus greening...

  20. La Roya naranja de la caña de azúcar, una enfermedad emergente: su impacto y comparación con la roya marrón English Translation: Orange rust of sugarcane, an emerging disease: its impact and comparison to brown rust.

    Science.gov (United States)

    Sugarcane orange rust, caused by Puccinia kuehnii, was first detected in Florida in 2007, the first for Western Hemisphere. Subsequently, it has spread to the majority of sugarcane producing countries in the hemisphere. Orange rust is distinguished from brown rust its pustule size which is slightl...

  1. The predatory mite Typhlodromalus aripo prefers green-mite induced plant odours from pubescent cassava varieties.

    Science.gov (United States)

    Onzo, Alexis; Hanna, Rachid; Sabelis, Maurice W

    2012-12-01

    It is well known that plant-inhabiting predators use herbivore-induced plant volatiles to locate herbivores being their prey. Much less known, however, is the phenomenon that genotypes of the same host plant species vary in the attractiveness of these induced chemical signals, whereas they also differ in characteristics that affect the predator's foraging success, such as leaf pubescence. In a series of two-choice experiments (using a Y-tube olfactometer) we determined the preference of Typhlodromalus aripo for pubescent versus glabrous cassava cultivars infested with the cassava green mite Mononychellus tanajoa and also the preference for cultivars within each of the two groups. We found that when offered a choice between pubescent and glabrous cassava cultivars (either apex or leaves), T. aripo was significantly more attracted to pubescent cultivars. For each cultivar, M. tanajoa infested leaves and apices were equally attractive to T. aripo. There was however some variation in the response of T. aripo to M. tanajoa-infested plant parts within the group of pubescent cultivars, as well as within the group of glabrous cultivars. Our study confirms not only that T. aripo uses herbivore-induced plant volatiles to search for prey in cassava fields, but it also shows that it can discriminate between glabrous and pubescent cultivars and prefers the latter. This knowledge can be useful in selecting cultivars that are attractive and suitable to T. aripo, which, in turn, may promote biological control of the cassava green mite.

  2. Using Landscape Genetics Simulations for Planting Blister Rust Resistant Whitebark Pine in the US Northern Rocky Mountains

    Science.gov (United States)

    Landguth, Erin L.; Holden, Zachary A.; Mahalovich, Mary F.; Cushman, Samuel A.

    2017-01-01

    Recent population declines to the high elevation western North America foundation species whitebark pine, have been driven by the synergistic effects of the invasive blister rust pathogen, mountain pine beetle (MPB), fire exclusion, and climate change. This has led to consideration for listing whitebark pine (WBP) as a threatened or endangered species under the Endangered Species Act, which has intensified interest in developing management strategies for maintaining and restoring the species. An important, but poorly studied, aspect of WBP restoration is the spatial variation in adaptive genetic variation and the potential of blister rust resistant strains to maintain viable populations in the future. Here, we present a simulation modeling framework to improve understanding of the long-term genetic consequences of the blister rust pathogen, the evolution of rust resistance, and scenarios of planting rust resistant genotypes of whitebark pine. We combine climate niche modeling and eco-evolutionary landscape genetics modeling to evaluate the effects of different scenarios of planting rust-resistant genotypes and impacts of wind field direction on patterns of gene flow. Planting scenarios showed different levels for local extirpation of WBP and increased population-wide blister rust resistance, suggesting that the spatial arrangement and choice of planting locations can greatly affect survival rates of whitebark pine. This study presents a preliminary, but potentially important, framework for facilitating the conservation of whitebark pine. PMID:28239390

  3. Using Landscape Genetics Simulations for Planting Blister Rust Resistant Whitebark Pine in the US Northern Rocky Mountains.

    Science.gov (United States)

    Landguth, Erin L; Holden, Zachary A; Mahalovich, Mary F; Cushman, Samuel A

    2017-01-01

    Recent population declines to the high elevation western North America foundation species whitebark pine, have been driven by the synergistic effects of the invasive blister rust pathogen, mountain pine beetle (MPB), fire exclusion, and climate change. This has led to consideration for listing whitebark pine (WBP) as a threatened or endangered species under the Endangered Species Act, which has intensified interest in developing management strategies for maintaining and restoring the species. An important, but poorly studied, aspect of WBP restoration is the spatial variation in adaptive genetic variation and the potential of blister rust resistant strains to maintain viable populations in the future. Here, we present a simulation modeling framework to improve understanding of the long-term genetic consequences of the blister rust pathogen, the evolution of rust resistance, and scenarios of planting rust resistant genotypes of whitebark pine. We combine climate niche modeling and eco-evolutionary landscape genetics modeling to evaluate the effects of different scenarios of planting rust-resistant genotypes and impacts of wind field direction on patterns of gene flow. Planting scenarios showed different levels for local extirpation of WBP and increased population-wide blister rust resistance, suggesting that the spatial arrangement and choice of planting locations can greatly affect survival rates of whitebark pine. This study presents a preliminary, but potentially important, framework for facilitating the conservation of whitebark pine.

  4. Irradiation as a phytosanitary treatment for mites of the specie Tyrophagus putrescentiae (Acari: Acaridae)

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Valter, E-mail: varthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radiobiologia e Ambiente; Mineiro, Jeferson L.C. [Instituto Biologico de Sao Paulo/APTA, Sao Paulo, SP (Brazil). Lab. de Entomologia Economico

    2009-07-01

    In great populations mites of the specie Tyrophagus putrescentiae can cause damages in stored products. The work had as objective to evaluate the effects of the gamma radiation of the Cobalt-60 to control the mites of the specie T. putrescentiae. The mites were irradiated with doses of 0 (control), 300, 400, 500, 600, 700, 800 Gy, in a source of Cobalt-60 type Gammacell-220, with a dose rate of 0.718 kGy/hour. Each treatment consisted of four repetitions containing 10 mites each, in a total of approximately 40 mites for treatment. The evaluations were daily, being counted the number of mites died, put eggs and emerged larvae. Based on the obtained results it was concluded that the dose sterilizing for the mites of this specie was of 300 Gy. Already the dose of 600 Gy induced the total mortality of the mites after 11 days of the irradiation process. (author)

  5. Mite (Arthropoda, Acari associates of palms (Arecaceae in Brazil I: present status and new records

    Directory of Open Access Journals (Sweden)

    Dalva L. Q. Santana

    1998-12-01

    Full Text Available This paper presents 72 new records and 10 records from literature on the distribuition of nine species of phytophagous mites and nine species of predatory mites from 13 species of palms in 13 Brazilian States.

  6. Deformed wing virus: replication and viral load in mites (Varroa destructor).

    Science.gov (United States)

    Gisder, Sebastian; Aumeier, Pia; Genersch, Elke

    2009-02-01

    Deformed wing virus (DWV) normally causes covert infections but can have devastating effects on bees by inducing morphological deformity or even death when transmitted by the ectoparasitic mite Varroa destructor. In order to determine the role of V. destructor in the development of crippled wings, we analysed individual mites for the presence and replication of DWV. The results supported the correlation between viral replication in mites and morphologically deformed bees. Quantification of viral genome equivalents revealed that mites capable of inducing an overt DWV infection contained 10(10)-10(12) genome equivalents per mite. In contrast, mites which could not induce crippled wings contained a maximum of only 10(8) viral genome equivalents per mite. We conclude that the development of crippled wings not only depends on DWV transmission by V. destructor but also on viral replication in V. destructor and on the DWV titre in the parasitizing mites.

  7. Ocular symptoms reported by patients infested with Demodex mites.

    Science.gov (United States)

    Sędzikowska, Aleksandra; Osęka, Maciej; Grytner-Zięcina, Barbara

    2016-12-01

    The purpose of this study was to determine subjective ocular symptoms occurring in patients infested with Demodex. The number of Demodex mites in the obtained material that correlated with the appearance of ocular symptoms was estimated. The study material were eyelashes collected from 1499 patients. The material were observed under a light microscope. T-test, the logistic regression method, and Pearson correlation coefficient were used for the analysis. Demodex mites were detected in 47% patients. The mean ages of infected women and men were 64 and 59 years, respectively. 64% infected patients complained of one or more ophthalmological symptoms. The most commonly reported symptoms included itching (28%), redness of eyelids (21%), and watery eyes (15%). Positive correlation was found between itching, redness, pain, purulence or eyelash loss and the presence of Demodex. The mentioned symptoms increase the probability of Demodex infestation in a statistically significant manner (pDemodex was revealed by the study. The threshold average number of seven Demodex mites per eight collected eyelashes with which the risk of the occurrence of an ocular symptom increases significantly was defined. In patients with a low number of Demodex mites, symptoms may be absent. The risk of the occurrence of ocular symptom in patients with demodicosis increases with the increase in the average number of Demodex mites.

  8. Acaricidal activity of eugenol based compounds against scabies mites.

    Directory of Open Access Journals (Sweden)

    Cielo Pasay

    Full Text Available BACKGROUND: Human scabies is a debilitating skin disease caused by the "itch mite" Sarcoptes scabiei. Ordinary scabies is commonly treated with topical creams such as permethrin, while crusted scabies is treated with topical creams in combination with oral ivermectin. Recent reports of acaricide tolerance in scabies endemic communities in Northern Australia have prompted efforts to better understand resistance mechanisms and to identify potential new acaricides. In this study, we screened three essential oils and four pure compounds based on eugenol for acaricidal properties. METHODOLOGY/PRINCIPAL FINDINGS: Contact bioassays were performed using live permethrin-sensitive S. scabiei var suis mites harvested from pigs and permethrin-resistant S. scabiei var canis mites harvested from rabbits. Results of bioassays showed that clove oil was highly toxic against scabies mites. Nutmeg oil had moderate toxicity and ylang ylang oil was the least toxic. Eugenol, a major component of clove oil and its analogues--acetyleugenol and isoeugenol, demonstrated levels of toxicity comparable to benzyl benzoate, the positive control acaricide, killing mites within an hour of contact. CONCLUSIONS: The acaricidal properties demonstrated by eugenol and its analogues show promise as leads for future development of alternative topical acaricides to treat scabies.

  9. Repeatability of feather mite prevalence and intensity in passerine birds.

    Directory of Open Access Journals (Sweden)

    Javier Diaz-Real

    Full Text Available Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and approaches were made to estimate R and adjusted repeatability (R(adj after controlling for potential confounding factors (breeding period, weather, habitat, spatial autocorrelation and researcher identity. The prevalence of feather mites was moderately repeatable (R = 0.26-0.53; R(adj = 0.32-0.57; smaller values were found for intensity (R = 0.19-0.30; R(adj = 0.18-0.30. These moderate repeatabilities show that prevalence and intensity of feather mites differ among species, but also that the high variation within species leads to considerable overlap among bird species. Differences in the prevalence and intensity of feather mites within bird species were small among habitats, suggesting that local factors are playing a secondary role. However, effects of local climatic conditions were partially observed for intensity.

  10. A rice Stowaway MITE for gene transfer in yeast.

    Directory of Open Access Journals (Sweden)

    Isam Fattash

    Full Text Available Miniature inverted repeat transposable elements (MITEs lack protein coding capacity and often share very limited sequence similarity with potential autonomous elements. Their capability of efficient transposition and dramatic amplification led to the proposition that MITEs are an untapped rich source of materials for transposable element (TE based genetic tools. To test the concept of using MITE sequence in gene transfer, a rice Stowaway MITE previously shown to excise efficiently in yeast was engineered to carry cargo genes (neo and gfp for delivery into the budding yeast genome. Efficient excision of the cargo gene cassettes was observed even though the excision frequency generally decreases with the increase of the cargo sizes. Excised elements insert into new genomic loci efficiently, with about 65% of the obtained insertion sites located in genes. Elements at the primary insertion sites can be remobilized, frequently resulting in copy number increase of the element. Surprisingly, the orientation of a cargo gene (neo on a construct bearing dual reporter genes (gfp and neo was found to have a dramatic effect on transposition frequency. These results demonstrated the concept that MITE sequences can be useful in engineering genetic tools to deliver cargo genes into eukaryotic genomes.

  11. Chemical control of the Asian citrus psyllid and of huanglongbing disease in citrus.

    Science.gov (United States)

    Boina, Dhana Raj; Bloomquist, Jeffrey R

    2015-06-01

    By 2014, huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus-growing regions of the world, including the United States, with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus-growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB-free seedlings and early detection and removal of symptomatic and asymptomatic trees, has been very effective in managing ACP. Area-wide management of ACP by application of insecticides at low volume in large areas of citrus cultivation has been shown to be effective in managing HLB and reducing management costs. As insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB-infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area-wide management programs with due consideration to the insecticide resistance problem. © 2014 Society of Chemical Industry.

  12. The influence of canopy density on willow leaf rust (Melampsora epitea) severity in willow short rotation coppice

    Energy Technology Data Exchange (ETDEWEB)

    Toome, M.; Heinsoo, K.; Holm, B.; Luik, A. [Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1A, Tartu 51014 (Estonia)

    2010-08-15

    Willow short rotation coppice is used as a renewable energy source and also as a vegetation filter for purifying wastewater. Wastewater irrigation might change microclimatic conditions and increase the canopy density in plantations, which might decrease production due to leaf rust (Melampsora epitea). The aim of this study was to estimate the impact of the canopy density on rust abundance on willows. For that, we counted rust pustules on leaves of five different willow clones from dense and sparse areas in both the wastewater irrigated and control part of the plantation. The results demonstrated clear differences between clones; clone '81090' was very susceptible, '78183' susceptible, '78021' fairly tolerant and 'Tora' rust resistant. Clone 'Gudrun', which was previously reported resistant, had severe rust damages in Estonia. In the case of clones '78183' and '78021' there were significantly more rust pustules per leaf unit area at areas with denser canopy, which confirmed that higher plant density could result in biomass losses caused by leaf rust. No differences, however, were detected between dense and sparse areas of hybrid clone 'Gudrun', most probably because in this particular case leaves from upper canopy layer were used. There was a tendency detected that clones with a higher number of shoots per plant had more rust damages on their leaves, however, the correlation was not statistically confirmed. In conclusion, the impact of canopy density on rust abundance is clone-specific and significant in the case of clones on which infection starts from the lower part of the canopy. (author)

  13. Analyses of mitogenome sequences revealed that Asian citrus psyllid (Diaphorina citri) from California was related to those from Florida but different from those in Southern China

    Science.gov (United States)

    Asian citrus psyllid (ACP, Diaphorina citri Kuwayama; Hemiptera: Liviidae) transmits “Candidatus Liberibacter asiaticus” (CLas), an unculturable alpha-proteobacterium associated with citrus Huanglongbing (HLB, yellow shoot disease, also called citrus greening disease). HLB is threatening citrus prod...

  14. Association analysis identifies Melampsora ×columbiana poplar leaf rust resistance SNPs.

    Directory of Open Access Journals (Sweden)

    Jonathan La Mantia

    Full Text Available Populus species are currently being domesticated through intensive time- and resource-dependent programs for utilization in phytoremediation, wood and paper products, and conversion to biofuels. Poplar leaf rust disease can greatly reduce wood volume. Genetic resistance is effective in reducing economic losses but major resistance loci have been race-specific and can be readily defeated by the pathogen. Developing durable disease resistance requires the identification of non-race-specific loci. In the presented study, area under the disease progress curve was calculated from natural infection of Melampsora ×columbiana in three consecutive years. Association analysis was performed using 412 P. trichocarpa clones genotyped with 29,355 SNPs covering 3,543 genes. We found 40 SNPs within 26 unique genes significantly associated (permutated P<0.05 with poplar rust severity. Moreover, two SNPs were repeated in all three years suggesting non-race-specificity and three additional SNPs were differentially expressed in other poplar rust interactions. These five SNPs were found in genes that have orthologs in Arabidopsis with functionality in pathogen induced transcriptome reprogramming, Ca²⁺/calmodulin and salicylic acid signaling, and tolerance to reactive oxygen species. The additive effect of non-R gene functional variants may constitute high levels of durable poplar leaf rust resistance. Therefore, these findings are of significance for speeding the genetic improvement of this long-lived, economically important organism.

  15. The rust genus Frommeëlla revisited: a later synonym of Phragmidium after all

    Science.gov (United States)

    Frommeëlla (Phragmidiaceae, Pucciniales, Basidiomycota) causes rust on members of tribe Potentilleae (Rosaceae). This genus currently includes two species and is typified by F. tormentillae. It has been distinguished from Phragmidium on the basis of having only one germ pore per cell of the teliospo...

  16. Resistance to the soybean rust pathogen (Phakopsora Pachyrhizi) in common bean cultivar CNC

    Science.gov (United States)

    Soybean rust (SBR), caused by Phakopsora pachyrhizi, is a new disease in the Americas that has moved swiftly from one country to another. P. pachyrhizi was first reported on soybeans in Paraguay (2001) and soon after in Brazil and Argentina (2002), Bolivia (2003), Uruguay and the USA, (2004), and M...

  17. Growing white pine in the Lake States to avoid blister rust

    Science.gov (United States)

    Eugene P. Van Arsdel

    1961-01-01

    Since white pine is one of the most desirable tree species for the Lake States region, it is unfortunate that fear of the blister rust disease has greatly limited the amount of white pine planted. Research has shown that, in many areas, loss from the disease has not been great even where pine stands have not been protected through ribes eradication. Conversely, in...

  18. Distribution of Ribes, an alternate host of white pine blister rust, in Colorado and Wyoming

    Science.gov (United States)

    Holly S. J. Kearns; William R. Jacobi; Kelly S. Burns; Brian W. Geils

    2008-01-01

    Ribes (currants and gooseberries) are alternate hosts for Cronartium ribicola, the invasive fungus that causes blister rust of white pines (Pinus, subgenus Strobus) in the Rocky Mountain region of Colorado and Wyoming. The location, species, and density of Ribes can affect...

  19. Aiding blister rust control by silvicultural measures in the western white pine type

    Science.gov (United States)

    Virgil D. Moss; Charles A. Wellner

    1953-01-01

    The forest industry of the Inland Empire depends on the production of western white pine (Pinus monticola Dougl.) as a major species. Continued production of this tree is impossible unless white pine blister rust (Cronartium ribicola Fischer) is controlled. Existing merchantable timber can and probably will be harvested before serious losses occur, but the young growth...

  20. Monitoring white pine blister rust infection and mortality in whitebark pine in the Greater Yellowstone ecosystem

    Science.gov (United States)

    Cathie Jean; Erin Shanahan; Rob Daley; Gregg DeNitto; Dan Reinhart; Chuck Schwartz

    2011-01-01

    There is a critical need for information on the status and trend of whitebark pine (Pinus albicaulis) in the Greater Yellowstone Ecosystem (GYE). Concerns over the combined effects of white pine blister rust (WPBR, Cronartium ribicola), mountain pine beetle (MPB, Dendroctonus ponderosae), and climate change prompted an interagency working group to design and implement...

  1. Limber pine forests on the leading edge of white pine blister rust distribution in Northern Colorado

    Science.gov (United States)

    Jennifer G. Klutsch; Betsy A. Goodrich; Anna W. Schoettle

    2011-01-01

    The combined threats of the current mountain pine beetle (Dendroctonus ponderosae, MPB) epidemic with the imminent invasion of white pine blister rust (caused by the non-native fungus Cronartium ribicola, WPBR) in limber pine (Pinus flexilis) forests in northern Colorado threatens the limber pine's regeneration cycle and ecosystem function. Over one million...

  2. In situ hybridization for the detection of rust fungi in paraffin embedded plant tissue sections

    Science.gov (United States)

    Rust fungi infect a wide range of plant species making them of particular interest to plant pathologists. In order to study the interactions between these important pathogenic fungi and their host plants it is useful to be able to differentiate fungal tissue from plant tissue. This can be accomplish...

  3. Identification of QTL for adult plant resistance to stripe rust in Chinese wheat landrace Caoxuan 5

    Science.gov (United States)

    Yellow (or stripe) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is an important wheat disease worldwide. The development of wheat cultivars with adult plant resistance (APR) has been given increasing emphasis in recent years because of the reputed durability of APR compared to all-stag...

  4. First report of Phakopsora pachyrhizi causing rust on soybean in Ethiopia

    Science.gov (United States)

    Soybean rust, caused by the fungal pathogen P. pachyrhizi, has been reported in 10 African countries since the first report in Uganda in 1996. In 2016, a severe epidemic caused “clouds” of urediniospores to be observed when walking through fields in mid-October 2016 in Jimma Ethiopia. In the first ...

  5. A new soybean rust resistance allele from PI 423972 at the Rpp4 locus

    Science.gov (United States)

    Phakopsora pachyrhizi is a fungal pathogen and the cause of Asian soybean rust (SBR). P. pachyrhizi invaded the continental United States in 2004 and has since been a threat to the soybean industry. There are six described loci that harbor resistance to P. pachyrhizi (Rpp) genes. The resistance of P...

  6. Host range of Phakopsora pachyrhizi, the causal agent of soybean rust

    Science.gov (United States)

    Phakopsora pachyrhizi, the causal organism of soybean rust, was first described in 1903 from leaves of Glycine max subsp. soja, or wild soybean, in Japan. Since that time, there have been numerous reports of the pathogen on various leguminous species around the world, first in Asia, followed by Aust...

  7. Molecular mapping of leaf rust resistance genes in the wheat line Yu 356-9

    Institute of Scientific and Technical Information of China (English)

    HAN Liu-sha; LI Zai-feng; WANG Jia-zhen; SHI Ling-zhi; ZHU Lin; LI Xing; LIU Da-qun; Syed J A Shah

    2015-01-01

    The Chinese wheat line Yu 356-9 exhibits a high level of resistance to leaf rust. In order to decipher the genetic base of resistance in Yu 356-9, gene postulation, inheritance analyses, and chromosome linkage mapping were carried out. Gene postulation completed using 15 leaf rust pathotypes and 36 isogenic lines indicated that Yu 356-9 was resistant to al pathotypes tested. F1 and F2 plants from the cross Yu 356-9 (resistant)/Zhengzhou 5389 (susceptible) were tested with leaf rust pathotype“FHNQ”in the greenhouse. Results indicated a 3:1 segregation ratio, indicative of the presence of a single dominant leaf rust resistance gene in Yu 356-9 which was temporarily designated as LrYu. Bulk segregant analysis and molecular marker assays were used to map LrYu. Five simple sequence repeat (SSR) markers on chromosome 2BS were found closely linked to LrYu. Among these markers, Xwmc770 is the most closely linked, with a genetic distance of 5.7 cM.

  8. The formation of green rust induced by tropical river biofilm components

    Energy Technology Data Exchange (ETDEWEB)

    Jorand, F., E-mail: jorand@pharma.uhp-nancy.fr [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France); Zegeye, A. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France); Ghanbaja, J. [Service Commun de Microscopies Electroniques et Microanalyses X (SCMEM), Nancy-Universite, Bvd des Aiguillettes, BP 239, 54506, Vandoeuvre-les-Nancy (France); Abdelmoula, M. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement (LCPME) UMR 7564, CNRS-Nancy-Universite, Institut Jean Barriol, 405 rue de Vandoeuvre, F-54600 Villers-les Nancy (France)

    2011-06-01

    In the Sinnamary Estuary (French Guiana), a dense red biofilm grows on flooded surfaces. In order to characterize the iron oxides in this biofilm and to establish the nature of secondary minerals formed after anaerobic incubation, we conducted solid analysis and performed batch incubations. Elemental analysis indicated a major amount of iron as inorganic compartment along with organic matter. Solid analysis showed the presence of two ferric oxides ferrihydrite and lepidocrocite. Bacteria were abundant and represented more than 10{sup 11} cells g{sup -1} of dry weight among which iron reducers were revealed. Optical and electronic microscopy analysis revealed than the bacteria were in close vicinity of the iron oxides. After anaerobic incubations with exogenous electron donors, the biofilm's ferric material was reduced into green rust, a Fe{sup II}-Fe{sup III} layered double hydroxide. This green rust remained stable for several years. From this study and previous reports, we suggest that ferruginous biofilms should be considered as a favorable location for GR biomineralization when redox conditions and electron donors availability are gathered. - Research highlights: {yields} Characterization of ferruginous biofilm components by solid analysis methods. {yields} Lepidocrocite and ferrihydrite were the main iron oxides. {yields} Anaerobic incubation of biofilm with electron donors produced green rust. {yields} Biofilm components promote the formation of the green rust. {yields} Ferruginous biofilm could contribute to the natural mercury attenuation.

  9. Determination of Rate of Degradation of Iron Plates Due To Rust Using Image Processing -A Review

    Directory of Open Access Journals (Sweden)

    Priyanka Choudhary

    2014-03-01

    Full Text Available Abstract: most of industries and bridges around us make use of iron for manufacturing their products. On the other hand corrosion is a natural process that deteriorates the integrity of iron surface. Therefore, rusting of iron takes place. To avoid unwanted accidents in industries and bridges, it is necessary to detect rusting in earlier stage, so that it can be prevented. Digital image processing for the detection of the rusting provides fast, accurate and objectives results. In this research paper, we have done a systematic review of algorithms that help us to detect the rust area from a metal (iron.it has been found that most of researches are bring their images, processing series in usage for this purpose due to its simplicity in implementing and due to fact the images help capturing the visual inspection process easily and due to the ground teeth. The image processing techniques explored by other peoples based on in-depth analysis, we have also proposed a novel technique to overcome the limitation.

  10. Determination of Rate of Degradation of Iron Plates due to Rust using Image Processing

    Directory of Open Access Journals (Sweden)

    Priyanka Choudhary

    2015-02-01

    Full Text Available Most of industries and bridges around us make use of iron for manufacturing their products. On the other hand corrosion is a natural process that deteriorates the integrity of iron surface. Therefore, rusting of iron takes place. To avoid unwanted accidents in industries and bridges, it is necessary to detect rusting in earlier stage, so that it can be prevented. Digital image processing for the detection of the rusting provides fast, accurate and objectives results. In this research paper, we have done a systematic review of algorithms that help us to detect the rust area from a metal (iron.it has been found that most of researches are bring their images, processing series in usage for this purpose due to its simplicity in implementing and due to fact the images help capturing the visual inspection process easily and due to the ground teeth. The image processing techniques explored by other peoples based on in-depth analysis, we have also proposed a novel technique to overcome the limitation.

  11. High diversity of genes for nonhost resistance of barley to heterologous rust fungi

    NARCIS (Netherlands)

    Jafary, H.; Albertazzi, G.; Marcel, T.C.; Niks, R.E.

    2008-01-01

    Inheritance studies on the nonhost resistance of plants would normally require interspecific crosses that suffer from sterility and abnormal segregation. Therefore, we developed the barley¿Puccinia rust model system to study, using forward genetics, the specificity, number, and diversity of genes in

  12. Microarray analysis of expressed sequence tags from haustoria of the rust fungus Uromyces fabae.

    Science.gov (United States)

    Jakupović, Mirza; Heintz, Manuel; Reichmann, Peter; Mendgen, Kurt; Hahn, Matthias

    2006-01-01

    Rust fungi are plant parasites which colonise host tissue with an intercellular mycelium that forms haustoria within living plant cells. To identify genes expressed during biotrophic growth, EST sequencing was performed with a haustorium-specific cDNA library from Uromyces fabae. One thousand seventeen ESTs were generated, which assembled into 530 contigs. Several of the most frequently represented sequences in the EST database were identical to the in planta induced genes (PIGs) identified previously (Hahn, M., Mendgen, K., 1997. Characterisation of in planta-induced rust genes isolated from a haustorium-specific cDNA library, Mol. Plant-Microbe Interact. 10, 427-437). Virus-encoded sequences were identified, providing evidence for two novel RNA mycoviruses in U. fabae. Microarray hybridisation revealed many cDNAs that were significantly activated in rust-infected leaves compared to germinated uredospores. Very strong in planta expression was found for two PIGs encoding putative metallothioneins. Furthermore, several genes involved in ribosome biogenesis and translation, glycolysis, amino acid metabolism, stress response, and detoxification showed an increased expression in the parasitic mycelium. These data indicate a strong shift in gene expression in rust fungi between germination and the biotrophic stage of development.

  13. Image processing methods for quantitatively detecting soybean rust from multispectral images

    Science.gov (United States)

    Soybean rust, caused by Phakopsora pachyrhizi, is one of the most destructive diseases for soybean production. It often causes significant yield loss and may rapidly spread from field to field through airborne urediniospores. In order to implement timely fungicide treatments for the most effective c...

  14. Label-Free Detection of Soybean Rust Spores using Photonic Crystal Biosensors

    Science.gov (United States)

    Soybean rust, caused by the fungus Phakopsora pachyrhizi, is one of the most devastating foliar diseases affecting soybeans grown worldwide. The disease was reported for the first time in the United States in 2004. Early spore detection, prior to the appearance of visible symptoms, is critical to ef...

  15. Options for the management of white pine blister rust in the Rocky Mountain Region

    Science.gov (United States)

    Kelly S. Burns; Anna W. Schoettle; William R. Jacobi; Mary F. Mahalovich

    2008-01-01

    This publication synthesizes current information on the biology, distribution, and management of white pine blister rust (WPBR) in the Rocky Mountain Region. In this Region, WPBR occurs within the range of Rocky Mountain bristlecone pine (Pinus aristata), limber pine (P. flexilis), and whitebark pine (P. albicaulis...

  16. Sources of stem rust resistance in wheat-alien introgression lines

    Science.gov (United States)

    Stem rust, caused by Puccinia graminis f. sp. tritici, is one of the most devastating diseases of wheat and the novel highly virulent race of TTKSK and its lineage are threatening wheat production worldwide. The objective of the study was to identify new sources of resistance in wheat-alien introgre...

  17. Selection for resistance to white pine blister rust affects the abiotic stress tolerances of limber pine

    Science.gov (United States)

    Patrick J. Vogan; Anna W. Schoettle

    2015-01-01

    Limber pine (Pinus flexilis) mortality is increasing across the West as a result of the combined stresses of white pine blister rust (Cronartium ribicola; WPBR), mountain pine beetle (Dendroctonus ponderosae), and dwarf mistletoe (Arceuthobium cyanocarpum) in a changing climate. With the continued spread of WPBR, extensive mortality will continue with strong selection...

  18. Control of Asian soybean rust with mancozeb, a multi-site fungicide

    Directory of Open Access Journals (Sweden)

    Luís Henrique Carregal Pereira da Silva

    2015-03-01

    Full Text Available An experiment conducted in the field the action of mancozeb, a fungicide of multi-site action was tested, to control soybean rust caused by Phakopsora pachyrhizi. Its performance was compared to that of the mixture cyproconazole (DMI + azoxystrobin (QoI. The soybean cultivar NA 7337 RR was used with a population of 400,000 plants/ha cultivated in 20m2 plots. Treatments consisted of mancozeb levels (1.5 and 2.0 kg/ha applied four, six and eight times. The DMI + QoI mixture was applied three times at 0.3 L/ha + Nimbus. Rust severity was assessed six times in the plots and data were integrated as the area under the disease progress curve (AUDPC. The plots were harvested and grain yield was expressed as kg/ha. Data on AUDPC and yield were subjected to analysis of variance and means compared according to Turkey's test (p = 0.005. Treatments with mancozeb were superior to DMI + QoI mixture both for rust control and grain yield. Four applications of 2.0 k/ha mancozeb were more efficient than three applications of the mixture used as standard. Mancozeb has the potential to be added to fungicide mixtures in the establishment of soybean rust anti-resistance strategy.

  19. Polymerase Chain Reaction (PCR) applications in white pine blister rust resistance screening

    Science.gov (United States)

    Sam Hendricks; Wendy Sutton; Jeffrey Stone; Richard Sniezko; Angelia Kegley; Anna Schoettle

    2011-01-01

    A goal of breeding programs for resistance to white pine blister rust is the development of multigenic resistance, even if the genetics and mechanisms of resistance may be imperfectly understood. The goal of multigenic resistance has prompted efforts to categorize host resistance reactions at increasingly finer scales, to identify heritable traits that may confer...

  20. The influence of white pine blister rust on seed dispersal in whitebark pine

    Science.gov (United States)

    Shawn T. McKinney; Diana F. Tomback

    2007-01-01

    We tested the hypotheses that white pine blister rust (Cronartium ribicola J.C. Fisch.) damage in whitebark pine (Pinus albicaulis Engelm.) stands leads to reduced (1) seed cone density, (2) predispersal seed survival, and (3) likelihood of Clark's Nutcracker (Nucifraga columbiana (Wilson, 1811)) seed...

  1. Multivariate analysis of stripe rust assessment and reactions of barley in multi-location nurseries

    Science.gov (United States)

    A total of 1357 entries, mainly consisting of hulled two-row, hulled six-row and hulless barley, were evaluated in stripe rust nurseries at Toluca, Mexico during 2007, Quito, Ecuador during 2007 and 2008, and Pullman and Mt. Vernon, USA [Pacific Northwest (PNW)] during 2007_2009. Disease screening d...

  2. First report of Phakopsora pachyrhizi causing rust on soybean in Malawi

    Science.gov (United States)

    Soybean rust (SBR), caused by Phakopsora pachyrhizi, has rapidly become established in Africa since the first report in Uganda in 1996. The urediniospores, as windborne propagules, have infested new regions of Africa, initiating SBR in many countries, including Ghana and Democratic Republic of the C...

  3. Histology of white pine blister rust in needles of resistant and susceptible eastern white pine

    Science.gov (United States)

    Joel A. Jurgens; Robert A. Blanchette; Paul J. Zambino; Andrew David

    2003-01-01

    White pine blister rust, Cronartium ribicola, has plagued the forests of North America for almost a century. Over past decades, eastern white pine (Pinus strobus) that appear to tolerate the disease have been selected and incorporated into breeding programs. Seeds from P. strobus with putative resistance were...

  4. URS Brava – a new oat cultivar with partial resistance to crown rust

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Federizzi

    2015-08-01

    Full Text Available The cultivar URS Brava, obtained from a simple cross between the line ‘UFRGS 995078-2’ and the cultivar ‘URS 21’, shows high grain yield and stability, high grain quality, desirable agronomical traits and partial resistance to crown rust, caused by the fungus Puccinia coronata f. sp. avenae.

  5. Research on the biology of fusiform rust in the southeastern United States

    Science.gov (United States)

    Pauline. Spaine

    1998-01-01

    The incidence of fusiform rust has continued to be one of the major forest disease problems in the Southeastern United States. In the past, much of the research has concentrated on field studies with provenance selection and genetic breeding of pine families to increase resistance in the host. In the last 10 years, there has been an increased interest in the actual...

  6. Introgression of a New Stem Rust Resistance Gene from Aegilops markgrafii into Wheat

    Science.gov (United States)

    In a prior study, we reported that an Alcedo/Aegilops markgrafii disomic addition line, AIII(D) (2n=44), was resistant to three races of the Ug99 lineage and five North American races of stem rust pathogen in wheat and the resistance originated from the alien chromosome. In this study, our objectiv...

  7. Expression of a synthetic rust fungal virus cDNA in yeast

    Science.gov (United States)

    Mycoviruses are viruses that infect fungi. Recently, mycovirus-like RNAs were sequenced from the fungus Phakopsora pachyrhizi, the causal agent of soybean rust. One of the RNAs appeared to represent a novel mycovirus and was designated Phakopsora pachyrhizi virus 2383 (PpV2383). The genome of PpV...

  8. First Report of Garlic Rust Caused by Puccinia allii on Allium sativum in Minnesota

    Science.gov (United States)

    In July 2010, Allium sativum, cultivar German Extra Hardy Porcelain plants showing foliar symptoms typical of rust infection were brought to the Plant Disease Clinic at the University of Minnesota by a commercial grower from Fillmore county Minnesota. Infected leaves showed circular to oblong lesio...

  9. Glycine buffered synthesis of layered iron(II)-iron(III) hydroxides (green rusts)

    DEFF Research Database (Denmark)

    Yin, Weizhao; Huang, Lizhi; Pedersen, Emil Bjerglund;

    2016-01-01

    Layered Fe(II)-Fe(III) hydroxides (green rusts, GRs) are efficient reducing agents against oxidizing contaminants such as chromate, nitrate, selenite, and nitroaromatic compounds and chlorinated solvents. In this study, we adopted a buffered precipitation approach where glycine (GLY) was used in ...

  10. First Report of Orange Rust of Sugarcane caused by Puccinia kuehnii in Ecuador

    Science.gov (United States)

    Orange rust, Puccinia kuehnii (W. Krüger) E.J. Butler, is an important disease of sugarcane (complex hybrid of Saccharum L. species) that causes yield losses, and impacts breeding programs. Initially confined to the Asia-Oceania region (5), P. kuehnii was reported in Florida in June 2007 (2) and lat...

  11. Molecular mapping of R11, a novel rust resistance gene in sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Sunflower production in North America has recently been threatened by the evolution of new virulent pathotypes of sunflower rust caused by the fungus Puccinia helianthi Schwein. Rf ANN-1742, an ‘HA 89’ backcross restorer line derived from wild annual sunflower (Helianthus annuus L), was identified a...

  12. Genetic architecture of resistance to stripe rust in a global winter wheat germplasm collection

    Science.gov (United States)

    Virulence shifts in populations of Puccinia striiformis f. sp. tritici (Pst), the causal pathogen of wheat stripe rust, are a major challenge to resistance breeding. The majority of known resistance genes are already ineffective against current races of Pst, necessitating the identification and intr...

  13. Dry Dog Food Integrity and Mite Strain Influence the Density-Dependent Growth of the Stored-Product Mite Tyrophagus putrescentiae (Acari: Acaridida).

    Science.gov (United States)

    Rybanska, Dagmar; Hubert, Jan; Markovic, Martin; Erban, Tomas

    2016-02-01

    The infestation of foodstuffs by mites is connected to health risks and economic losses. The cosmopolitan stored-product mite Tyrophagus putrescentiae (Schrank, 1781) is an emerging and predominant pest of dry dog food. In this study, the influences on mite population growth of 1) the different dry dog food kernels present in the package; 2) the integrity of the dry dog food kernel, whether intact or crushed; 3) the initial population density of 10 or 100 specimens; and 4) the four mite strains used were investigated under laboratory conditions. The population growth tests were performed for 28 d at 85% relative humidity and 25°C. The intrinsic growth rates of the mites were compared. The population growth was higher on the brown and green kernels than on the red and white kernels. The kernel integrity affected the population growth, and the integrity effect was highly influenced by the initial mite population density. The mites showed density-dependent growth in three of the four mite strains tested. The initial population density changed the population growth ranking among the mite strains, thereby indicating strain-specific density-dependent growth. The results of this study have important implications for predictive models of stored-product mite populations in dry dog food. One practical recommendation is that the growth of mites should be considered with regard to the mite strains and according to the strain-specific density dependent growth. Next, the integrity of the kernels should be maintained because disrupted or crushed kernels promote increases in mite populations.

  14. Candidate predators for biological control of the poultry red mite Dermanyssus gallinae

    NARCIS (Netherlands)

    Lesna, Izabela; Wolfs, Peter; Faraji, Farid; Roy, Lise; Komdeur, Jan; Sabelis, Maurice W.

    2009-01-01

    The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify poten

  15. Laboratory evaluation of the effect of inert dust formulations on the poultry red mite, Dermanyssus gallinae

    DEFF Research Database (Denmark)

    Kilpinen, Ole; Steenberg, Tove

    In the EU-project SAFEHOUSE one objective is to develop alternative control methods against poultry red mites based on a combination of inert dusts and mite-pathogenic fungal isolates. Both components have some pathogenicity to the mites. However, the question is whether a combination of the two ...

  16. Heritability of defence and life-history traits in the two-spotted spider mite

    NARCIS (Netherlands)

    Tien, N.S.H.; Sabelis, M.W.; Egas, M.

    2009-01-01

    Background: Two-spotted spider mites hide against predatory mites in a web of self-produced sticky silk. The proteins invested in this shelter may reduce investment in reproduction. Questions: Do spider mite populations harbor genetic variation for web production, thereby enabling a response to

  17. Are Demodex mites principal, conspirator, accomplice, witness or bystander in the cause of rosacea?

    Science.gov (United States)

    Chen, WenChieh; Plewig, Gerd

    2015-04-01

    As the only permanent human ectoparasite, the role of human Demodex mites in health and diseases remains largely unclarified. In view of the ecological interaction between organisms of two different species, a type of commensalism between Demodex mites and humans (the former benefit, the latter unaffected) is most likely, while parasitism occurs temporarily and spatially in the diseased state (the former benefit, the latter harmed). As part of normal skin microbiota, the causal role of Demodex mites in the initiation of rosacea can neither fulfill the classical Henle-Koch's principal nor the advanced criteria proposed by Fredericks and Relman for molecular detection of non-cultivatable microorganisms. Epidemiological analysis using Hill's criteria fails to support the causative role of Demodex mites in rosacea regarding the strength of association, specificity and temporality of association, biological gradient and plausibility as well as clinical coherence, therapeutic experimentation and medical analogy. In application of Rothman's sufficient cause model to evaluate the contribution of Demodex mites to rosacea on a population basis, Demodex mites can be regarded as a non-necessary, non-sufficient causal factor for certain forms of rosacea. Further strategies to dissect the association between Demodex mites and rosacea may include studying the possible existence of more virulent forms of mites with a higher pathogenicity, the endosymbiotic bacteria in certain life periods of mites, the interactions between mites and human hosts or between mites and environment, and to set up ex vivo culture models for Demodex mites.

  18. [Ecological data on house dust mites in the city of Semipalatinsk].

    Science.gov (United States)

    Iagofarov, F F; Galikeev, Kh L

    1987-01-01

    Distribution of mites of the genus Dermatophagoides in flats of allergic patients depending on the type of the building structure, relative air humidity and season of the year was studied. The mites are most frequently encountered in houses of wood or adobe with high air humidity. Autumn is an optimum season for reproduction of mites.

  19. Mechanisms of insecticide resistance in field populations of varroa mite (Acari: Mesostigmata: Varroidae)in Florida

    Science.gov (United States)

    The ectoparasitic mite Varroa destuctor is a serious threat to beekeeping and crops that rely on honey bee for pollination. The Varroa mite not only causes significant damage to honey bees by feeding on their haemolymph, but also serves as a vector of disease. In addition, the Varroa mite has develo...

  20. Heritability of defence and life-history traits in the two-spotted spider mite

    NARCIS (Netherlands)

    Tien, N.S.H.; Sabelis, M.W.; Egas, M.

    2009-01-01

    Background: Two-spotted spider mites hide against predatory mites in a web of self-produced sticky silk. The proteins invested in this shelter may reduce investment in reproduction. Questions: Do spider mite populations harbor genetic variation for web production, thereby enabling a response to sele