Critical disease components of common bacterial blight to effectively evaluate resistant genotypes of snap bean     

Roberto dos Santos Trindade  Rosana Rodrigues  Ant?nio Teixeira do Amaral Júnior  Leandro Sim?es Azeredo Gon?alves  Rogério Figueiredo Daher  Cláudia Pombo Sudré 《Journal of General Plant Pathology》2012,78(3):201-206

Common bacterial blight (CBB) caused by Xanthomonas axonopodis pv. phaseoli (Xap) is the main bacterial disease of snap bean. The present work aimed to select snap bean genotypes that are resistant to CBB based on three components of resistance: area under the disease progress curve, latent period, and lesion diameter on pods (DL). A completely randomized two-factor factorial design with six replications was used to evaluate leaves and pods of 14 snap bean and three common bean genotypes (PI 207262, BAC-6 and A-794) with high resistance to CBB. Two Xap isolates, 1394-98 and 775-90, were used to inoculate leaves and pods. Data were analyzed using nonparametric statistics. Significant differences were observed among the evaluated genotypes for all of the components of resistance, except for DL. The snap bean UENF 1482 demonstrated good performance in two disease resistance components. For this reason, this genotype can be recommended for use in breeding programs that aim to generate snap bean genotypes resistant to Xanthomonas axonopodis pv. phaseoli.  相似文献   

Resonance of scantlings indicates the stiffness even of small specimens of Eucalyptus from plantations     

Paulo Ricardo Gherardi Hein  José Tarcísio Lima  Joseph Gril  Ant?nio Marcos Rosado  Lo?c Brancheriau 《Wood Science and Technology》2012,46(4):621-635

The aim of this study was to establish the relationship between the stiffness of scantlings, approaching structural size materials, and small specimens of 6-year-old Eucalyptus urophylla?×?grandis wood using a resonance technique. The correlation between the elastic modulus (E) of the scantlings in longitudinal vibration and small specimens in flexural vibration was r?=?75 when comparing the scantling values with the averaged values of the specimens per scantling. However, when the E of each single specimen was compared with its respective scantling, the coefficient of correlation decreased to r?=?0.64 in the longitudinal tests and r?=?0.61 in the flexural tests. A roughly linear correlation (r?=?0.59) between specific modulus and loss tangent was obtained for the small specimens of Eucalyptus. In short, the resonance technique rapidly provided a large, accurate data set of mechanical wood properties as required for high-throughput phenotyping in recent genetic studies.  相似文献   

Seroprevalence and risk factors for Neospora caninum in sheep in the state Minas Gerais, southeastern Brazil     

da Silva Andrade G  Bruhn FR  Rocha CM  Guimarães Ade S  Gouveia AM  Guimarães AM 《Veterinary parasitology》2012,188(1-2):168-171

The aim of this study was to determine the prevalence and risk factors associated with infection due to Neospora caninum in serum samples from 488 sheep originating from 63 farms in 63 municipalities distributed across eight of the twelve mesoregions of the state Minas Gerais, southeastern Brazil. For detection of N. caninum the sheep serum samples were subjected to the indirect fluorescence antibody test (IFAT ≥ 50). To identify the risk factors associated with infection due to N. caninum a questionnaire was filled out for each herd by interviewing, the individual responsible for the herd, demanding information on the general characteristics of the property. Sixty-four sheep sera (13.1%; 95% CI=10.3-16.4) presented IgG-specific anti-N. caninum antibodies with the following titers: 50 (49; 76.6%), 100 (7; 10.9%), 200 (4; 6.2%), 400 (3; 4.7%) and 800 (1; 1.6%). The prevalence of infected sheep per mesoregion ranged from 0 to 28.1%. Out of the 63 farms sampled, 31 (49.2%; 95% CI=36.4-62.1) presented at least one seropositive sheep. No significant association was found between the presence of anti-N. caninum antibodies and the risk factors evaluated on the farms, except for the mesoregion variable (p=0.004; OR=0.429; CI95%=0.182-1.008). These results indicate that there is a need for additional research to define the epidemiological importance of this parasite as a cause of reproductive problems in sheep herds in Minas Gerais.  相似文献   

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes     

Taciana MF Silva  Roberio G Olinda  Carla MF Rodrigues  Ant?nio CL Camara  Francisco C Lopes  Wesley AC Coelho  Múcio FB Ribeiro  Carlos IA Freitas  Marta MG Teixeira  Jael S Batista 《Veterinary research》2013,44(1):1

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.  相似文献   

Dietary roughage sources affect lactating Holstein x Zebu cows under experimental conditions in Brazil: a meta-analysis     

Alessio  Dileta Regina Moro  Velho  João Pedro  Tambara  Antônio Augusto Cortiana  de Oliveira Gomes  Ivan Pedro  Knob  Deise Aline  Haygert-Velho  Ione Maria Pereira  Busanello  Marcos  Thaler Neto  André 《Tropical animal health and production》2020,52(1):185-193

Tropical Animal Health and Production - To reduce costs, lactating cows are often fed a higher proportion of roughage and alternative feeds; however, such protocols may not lead to optimal milk...  相似文献   

Landscape structure shapes carnivore-mediated seed dispersal kernels     

José M. Herrera  Isa de Sá Teixeira  Javier Rodríguez-Pérez  António Mira 《Landscape Ecology》2016,31(4):731-743

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Integrating land cover structure and functioning to predict biodiversity patterns: a hierarchical modelling framework designed for ecosystem management     

Rita Bastos  António T. Monteiro  Diogo Carvalho  Carla Gomes  Paulo Travassos  João P. Honrado  Mário Santos  João Alexandre Cabral 《Landscape Ecology》2016,31(4):701-710

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The effects of tank colours on the growth and survival of cuttlefish (Sepia officinalis,Linnaeus 1758) hatchlings and juveniles     

António V Sykes  Pedro M Domingues  Lorenzo Márquez  José P Andrade 《Aquaculture Research》2011,42(3):441-449

The effects of different tank colours (white, yellow sandy and black) on the growth, mortality and biomass production were studied for hatchling and early juvenile cuttlefish. For hatchlings, the use of different colour tanks did not promote differences in growth due to the higher variability (standard deviation) found in the white‐ and sand‐coloured tanks. Black tanks promoted the lowest and highest values for total mortality and biomass respectively. For juveniles, the use of different tank colours promoted different growth (P<0.05), but not mortality. Black tanks promoted the best results in terms of growth and biomass. The results obtained in the present study advise the use of black (or dark colour) tanks in the hatchling and early juvenile stages to reduce the standard deviations associated with growth, mortality and biomass production. This will contribute to minimize problems associated with slow and fast growers and competition.  相似文献   

The effects of temperature and photoperiod on egg hatching success,egg production and population growth of the calanoid copepod,Acartia grani (Calanoida: Acartiidae)          下载免费PDF全文

Natacha Nogueira  Bernardo Sumares  Carlos Alberto Pestana Andrade  António Afonso 《Aquaculture Research》2018,49(1):93-103

Calanoid copepods, including species of the genus Acartia, are commonly used as larval diets for marine finfish. This study aimed to determine the separate effects of water temperature (18, 22, 24, 28° ± 0.5°C) and photoperiod (24L:0D; 18L:6D; 12L:12D; 8L:18D; 0L:24D) on Acartia grani egg production (EP), hatching rate (EHR) and population growth. Egg production rate was not affected by the two abiotic parameters. A. grani eggs incubated at T24°C and T28°C were the first to achieve 50% hatching rate (23–25 hr), with significant differences at the end of the experiment (48 hr) between T28°C treatment (EHR 88 ± 5%) and T18°C treatment (EHR 65 ± 2%). However, different temperature regimes did not affect final number of individuals in population growth experiment. Still, when eggs were excluded from data, population at lower temperatures (18°C) was mainly composed by the nauplii stage (72%), while at higher temperatures (24°C and 28°C) more than 60% of the population was composed by copepodites and adults. A. grani subjected to long‐day photoperiods had significantly lower EHR (16.7% at 24L:0D; 20.8% at 18L:6D) than at short‐day photoperiods (52.6% at 6L:18D; 50.0% at 0L:24D). In population growth experiment, eggs were the most common life stage after 12‐day culture. Lowest population number was found at constant light conditions (665.0 ± 197.1), suggesting higher metabolic rates and depletion of energy reserves in long‐day conditions. This study expanded knowledge on the biological response of A. grani to separate temperature and photoperiod regimes, and provided ground to improve the culture of this potential life feed species for hatcheries.  相似文献   

Influence of the Processing Parameters on the Characteristics of Spherical Bacterial Cellulose     

Ricardo Brandes  Letícia de Souza  Daniel V. F. Vanin  Claudimir A. Carminatti  Eliana M. Oliveira  Regina V. Antônio  Derce O. S. Recouvreux 《Fibers and Polymers》2018,19(2):297-306

Bacterial Cellulose (BC) biosynthesized under agitated conditions can produce hydrogels with spherical shapes and the processing parameters govern this formation of BC hydrogels. The variations of these parameters cause different results in the formation of spherical BC and it is relevant to evaluate these effects. Carbon source, inoculum concentration, volume of the culture medium, stirring speed and incubation temperature were the processing parameters evaluated in this work. Therefore, the results obtained were characterized in terms of dry mass production, water uptake and sphericity of the spherical BC. To do so, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were employed as tools for morphological and chemical evaluations. Among the parameters analyzed, the carbon source had the greatest effect on the production of dry mass and water uptake. Glycerol had the greatest growing rate, generating a higher dry mass production with spherical and homogeneous bodies with excellent water absorption indexes. Furthermore, the morphological analysis of BC revealed a typical structure, with high crystallinity index and the presence of typical functional groups. These results indicate a path for the optimized and controlled production of spherical BC, allowing it to be used in many applications, such as enzyme immobilization, water treatment, bone regeneration, spherical cancer model, as adsorption agent and drug delivery.  相似文献