198 research outputs found

    Metodologia do perfil cultural

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    Genetic evaluation of Jatropha curcas: an important oilseed for biodiesel production

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    Jatropha curcas, internationally and locally known, respectively, as physic nut and pinhão manso, is a highly promising species for biodiesel production in Brazil and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority for biodiesel programs in Brazil. Consequently, this species merits genetic investigations aimed at improving yields. Some studies have detected genetic variability in accessions in Africa and Asia. We have made the first genetic evaluation of J. curcas collected from Brazil. Our objective was to quantify genetic diversity and to estimate genetic parameters for growth and production traits and seed oil content. We evaluated 75 J. curcas progenies collected from Brazil and three from Cambodia. The mean oil content in the seeds was 31%, ranging from 16 to 45%. No genetic correlation between growth traits and seed oil content was found. However, high coefficients of genetic variation were found for plant height, number of branches, height of branches, and stem diameter. The highest individual narrow-sense heritabilities were found for leaf length (0.35) and width (0.34), stem diameter (0.24) and height of branches (0.21). We used a clustering algorithm to genetically identify the closest and most distant progenies, to assist in the development of new cultivars. Geographical diversity did not necessarily represent the genetic diversity among the accessions collected. These results are important for the continuity of breeding programs, aimed at obtaining cultivars with high grain yield and high oil content in seeds

    Distribution of hepatitis C virus genotypes among blood donors from mid-west region of Brazil

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    In order to investigate the hepatitis C virus (HCV) genotypes in mid-west region of Brazil, 250 anti-HCV positive blood donors were studied. Among them, the anti-HCV serological status was confirmed in 205 (82%). HCV RNA was detected in 165 samples, which were genotyped. HCV types 1, 2 and 3 were found in 67.9%, 3% and 29.1% of the donors, respectively. In Goiás state, subtype 1a (50%) was the most prevalent, followed by subtypes 3a (30.9%) and 1b (16.7%). In Mato Grosso state, subtype 1a was also predominant (41%), followed by subtypes 1b (29.5%) and 3a (25%). In Mato Grosso do Sul state, subtypes 1a and 1b were detected equally (36.8%), followed by 3a (21.1%). Subtype 2b was rare (2.4%, 4.5% and 5.3%, respectively). In Distrito Federal, subtype 3a (39%) was more frequent than 1a (31.7%) and the remaining (29.3%) belonged to subtype 1b.Com objetivo de determinar os genótipos do vírus da hepatite C (HCV) circulantes na Região Centro-Oeste do Brasil, 250 doadores de sangue anti-HCV positivos foram estudados. Dentre eles, a positividade para anti-HCV foi confirmada em 205 (82%). O RNA-HCV foi detectado em 165 amostras, as quais foram genotipadas. Os tipos 1, 2 e 3 do HCV foram encontrados em 67,9%, 3% e 29,1% dos doadores, respectivamente. No Estado de Goiás, o subtipo 1a (50%) foi o mais prevalente, seguido pelos subtipos 3a (30,9%) e 1b (16,7%). No Estado de Mato Grosso, o subtipo 1a (41%) foi também predominante, seguido pelos subtipos 1b (29,5%) e 3a (25%). No Estado de Mato Grosso do Sul, os subtipos 1a e 1b foram igualmente detectados (36,8%), seguidos por 3a (21,1%). O subtipo 2b foi raro (2,4%, 4,5% e 5,3%, respectivamente). No Distrito Federal, o subtipo 3a (39%) foi mais freqüente que 1a (31,7%), sendo o restante (29,3%) identificado como subtipo 1b

    Behavioral responses of Diaphorina citri to host plant volatiles in multiple-choice olfactometers are affected in interpretable ways by effects of background colors and airflows

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    [EN] In several phytophagous hemipterans, behavior appears to be mediated by both visual and chemical cues. For the Asian citrus psyllid (ACP)Diaphorina citri(Hemiptera: Liviidae), olfactometric assays are generally difficult to interpret owing to the low proportion of individuals responding to odors (similar to 30-40%), which compromises the efficiency and reliability of the results of behavioral tests. In the present study, the ACP behavioral response to emitted odors from sweet orange (Citrus sinensisL. Osbeck) flushes in a 4-arm olfactometer using different colors (four white-, two white- and two yellow- on opposite sides, or four yellow-colored fields), and the role of the airflow in the concentration of volatile organic compounds (VOCs) were assessed at two airflows [0.4 and 0.1 L/min (LPM)]. Exposure to 'Pera' sweet orange or clean air in treatments with four yellow-colored-fields increased the response rate of ACP females to the odor sources compared with exposure to 'Pera' sweet orange or clean air in treatments with four white-colored-fields, independently of the odor source and airflow tested. For the assays using two white- and two yellow-colored fields on opposite sides and 0.4 or 0.1 LPM airflow, the residence time of ACP females to odors ('Pera' sweet orange or clean air) was similar or higher in treatments using yellow- than those using white-colored fields. For both assays (VOCs and olfactometric behavioral parameters), the reduction in airflow from 0.4 to 0.1 LPM greatly changed the airborne concentration and ACP behavior. Quantitative chemical analyses revelead that the concentration of most compounds emitted by 'Pera' sweet orange flushes for the headspace using 0.1 LPM airflow were greater than the concentrations measured using 0.4 LPM airflow. Therefore, this treatment design provides an useful tool to assess the ACP behavioral response to the odors from citrus plants, and it can also help in the discrimination of dose-response screenings for VOCs or conspecific insects.Financial support was provided by Sao Paulo Research Foundation (FAPESP) 2015/07011-3 and 2017/21460-0. The authors thank Dr. Aquidauana Miqueloto Zanardi for her help in measuring the color spaces of the white and yellow reflective papers used to change the device color.Volpe, H.; Zanardi, O.; Magnani, R.; Luvizotto, R.; Esperança, V.; De Freitas, R.; Delfino, J.... (2020). Behavioral responses of Diaphorina citri to host plant volatiles in multiple-choice olfactometers are affected in interpretable ways by effects of background colors and airflows. PLoS ONE. 15(7):1-17. https://doi.org/10.1371/journal.pone.0235630S117157Grafton-Cardwell, E. E., Stelinski, L. L., & Stansly, P. A. (2013). Biology and Management of Asian Citrus Psyllid, Vector of the Huanglongbing Pathogens. Annual Review of Entomology, 58(1), 413-432. doi:10.1146/annurev-ento-120811-153542Tiwari, S., Mann, R. S., Rogers, M. E., & Stelinski, L. L. (2011). Insecticide resistance in field populations of Asian citrus psyllid in Florida. Pest Management Science, 67(10), 1258-1268. doi:10.1002/ps.2181Zanardi, O. Z., Bordini, G. P., Franco, A. A., de Morais, M. R., & Yamamoto, P. T. (2018). Spraying pyrethroid and neonicotinoid insecticides can induce outbreaks of Panonychus citri (Trombidiformes: Tetranychidae) in citrus groves. Experimental and Applied Acarology, 76(3), 339-354. doi:10.1007/s10493-018-0316-1Stockton, D. G., Martini, X., Patt, J. M., & Stelinski, L. L. (2016). The Influence of Learning on Host Plant Preference in a Significant Phytopathogen Vector, Diaphorina citri. PLOS ONE, 11(3), e0149815. doi:10.1371/journal.pone.0149815Knolhoff, L. M., & Heckel, D. G. (2014). Behavioral Assays for Studies of Host Plant Choice and Adaptation in Herbivorous Insects. Annual Review of Entomology, 59(1), 263-278. doi:10.1146/annurev-ento-011613-161945Döring, T. F., & Chittka, L. (2007). Visual ecology of aphids—a critical review on the role of colours in host finding. Arthropod-Plant Interactions, 1(1), 3-16. doi:10.1007/s11829-006-9000-1NISSINEN, A., KRISTOFFERSEN, L., & ANDERBRANT, O. (2008). Physiological state of female and light intensity affect the host-plant selection of carrot psyllid, Trioza apicalis (Hemiptera: Triozidae). European Journal of Entomology, 105(2), 227-232. doi:10.14411/eje.2008.032MOUND, L. A. (1962). STUDIES ON THE OLFACTION AND COLOUR SENSITIVITY OF BEMISIA TABACI (GENN.) (HOMOPTERA, ALEYRODIDAE). Entomologia Experimentalis et Applicata, 5(2), 99-104. doi:10.1111/j.1570-7458.1962.tb00571.xAntignus, Y., Mor, N., Ben Joseph, R., Lapidot, M., & Cohen, S. (1996). Ultraviolet-Absorbing Plastic Sheets Protect Crops from Insect Pests and from Virus Diseases Vectored by Insects. Environmental Entomology, 25(5), 919-924. doi:10.1093/ee/25.5.919Hall, D. G., Sétamou, M., & Mizell, R. F. (2010). A comparison of sticky traps for monitoring Asian citrus psyllid (Diaphorina citri Kuwayama). Crop Protection, 29(11), 1341-1346. doi:10.1016/j.cropro.2010.06.003Godfrey, K. E., Galindo, C., Patt, J. M., & Luque-Williams, M. (2013). Evaluation of Color and Scent Attractants Used to Trap and Detect Asian Ctirus Psyllid (Hemiptera: Liviidae) in Urban Environments. Florida Entomologist, 96(4), 1406-1416. doi:10.1653/024.096.0420Sétamou, M., Sanchez, A., Saldaña, R. R., Patt, J. M., & Summy, R. (2014). Visual Responses of Adult Asian Citrus Psyllid (Hemiptera: Liviidae) to Colored Sticky Traps on Citrus Trees. Journal of Insect Behavior, 27(4), 540-553. doi:10.1007/s10905-014-9448-2Miranda, M. P., Dos Santos, F. L., Felippe, M. R., Moreno, A., & Fereres, A. (2015). Effect of UV-Blocking Plastic Films on Take-Off and Host Plant Finding Ability of Diaphorina citri (Hemiptera: Liviidae). Journal of Economic Entomology, 108(1), 245-251. doi:10.1093/jee/tou036Paris, T. M., Croxton, S. D., Stansly, P. A., & Allan, S. A. (2015). Temporal response and attraction ofDiaphorina citrito visual stimuli. Entomologia Experimentalis et Applicata, 155(2), 137-147. doi:10.1111/eea.12294Patt, J. M., & Sétamou, M. (2010). Responses of the Asian Citrus Psyllid to Volatiles Emitted by the Flushing Shoots of Its Rutaceous Host Plants. Environmental Entomology, 39(2), 618-624. doi:10.1603/en09216Amorós, M. E., Pereira das Neves, V., Rivas, F., Buenahora, J., Martini, X., Stelinski, L. L., & Rossini, C. (2018). Response of Diaphorina citri (Hemiptera: Liviidae) to volatiles characteristic of preferred citrus hosts. Arthropod-Plant Interactions, 13(3), 367-374. doi:10.1007/s11829-018-9651-8George, J., Shi, Q., Stelinski, L. L., Stover, E., & Lapointe, S. L. (2019). Host Selection, Oviposition and Feeding by a Phytopathogen Vector, Diaphorina citri (Hemiptera: Liviidae), Modulated by Plant Exposure to Formic Acid. Frontiers in Ecology and Evolution, 7. doi:10.3389/fevo.2019.00078Pettersson, J. (1970). An Aphid Sex Attractant. Insect Systematics & Evolution, 1(1), 63-73. doi:10.1163/187631270x00357VET, L. E. M., LENTEREN, J. C. V., HEYMANS, M., & MEELIS, E. (1983). An airflow olfactometer for measuring olfactory responses of hymenopterous parasitoids and other small insects. Physiological Entomology, 8(1), 97-106. doi:10.1111/j.1365-3032.1983.tb00338.xWenninger, E. J., Stelinski, L. L., & Hall, D. G. (2009). Roles of Olfactory Cues, Visual Cues, and Mating Status in Orientation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) to Four Different Host Plants. Environmental Entomology, 38(1), 225-234. doi:10.1603/022.038.0128Onagbola, E. O., Rouseff, R. L., Smoot, J. M., & Stelinski, L. L. (2010). Guava leaf volatiles and dimethyl disulphide inhibit response of Diaphorina citri Kuwayama to host plant volatiles. Journal of Applied Entomology, 135(6), 404-414. doi:10.1111/j.1439-0418.2010.01565.xAlquézar, B., Volpe, H. X. L., Magnani, R. F., de Miranda, M. P., Santos, M. A., Wulff, N. A., … Peña, L. (2017). β-caryophyllene emitted from a transgenic Arabidopsis or chemical dispenser repels Diaphorina citri, vector of Candidatus Liberibacters. Scientific Reports, 7(1). doi:10.1038/s41598-017-06119-wTomaseto, A. F., Miranda, M. P., Moral, R. A., de Lara, I. A. R., Fereres, A., & Lopes, J. R. S. (2017). Environmental conditions for Diaphorina citri Kuwayama (Hemiptera: Liviidae) take-off. Journal of Applied Entomology, 142(1-2), 104-113. doi:10.1111/jen.12418Wenninger, E. J., & Hall, D. G. (2007). Daily Timing of Mating and Age at Reproductive Maturity in Diaphorina citri (Hemiptera: Psyllidae). Florida Entomologist, 90(4), 715-722. doi:10.1653/0015-4040(2007)90[715:dtomaa]2.0.co;2Shapiro, S. S., & Wilk, M. B. (1965). An Analysis of Variance Test for Normality (Complete Samples). Biometrika, 52(3/4), 591. doi:10.2307/2333709Nelder, J. A., & Wedderburn, R. W. M. (1972). Generalized Linear Models. Journal of the Royal Statistical Society. Series A (General), 135(3), 370. doi:10.2307/2344614Wilcoxon, F. (1945). Individual Comparisons by Ranking Methods. Biometrics Bulletin, 1(6), 80. doi:10.2307/3001968Patt, J. M., Meikle, W. G., Mafra-Neto, A., Sétamou, M., Mangan, R., Yang, C., … Adamczyk, J. J. (2011). Multimodal Cues Drive Host-Plant Assessment in Asian Citrus Psyllid (Diaphorina citri). Environmental Entomology, 40(6), 1494-1502. doi:10.1603/en11149Todd, J. W., Kays, S. J., & Kays, S. E. (1977). A precision low-flow-rate air delivery system for use with olfactometers. Journal of Chemical Ecology, 3(5), 519-525. doi:10.1007/bf00989073Bruce, T. J. A., Wadhams, L. 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    Soil cover plants on water erosion control in the South of Minas Gerais

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    Water erosion is responsible for soil, water, carbon and nutrient losses, turning into the most important type of degradation of Brazilian soils. This study aimed to evaluate the influence of three cover plants under two tillage systems on water erosion control in an Argisol at south of Minas Gerais state, Brazil. The cover plants utilized in the study were pigeon pea, jack bean and millet, under contour seeding and downslope tillage. Experimental plots of 4 x 12 m, with 9% slope, under natural rainfall were used for the quantification of losses of soil, water, nutrients, and organic matter. One experimental plot was kept without plant cover (reference). Higher erosivity was observed in December and January, although a great quantity of erosive rainfall was detected during the whole raining period. Contour seeding provided a greater reduction of water erosion than downslope tillage, as expected. The jack bean under contour seeding revealed the lowest values of soil, water, nutrients and organic matter losses

    Infrastructure for Detector Research and Development towards the International Linear Collider

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    The EUDET-project was launched to create an infrastructure for developing and testing new and advanced detector technologies to be used at a future linear collider. The aim was to make possible experimentation and analysis of data for institutes, which otherwise could not be realized due to lack of resources. The infrastructure comprised an analysis and software network, and instrumentation infrastructures for tracking detectors as well as for calorimetry.Comment: 54 pages, 48 picture
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