Brusone no arroz.

Manejo integrado da brusone. O que é a brusone?. Quais os sintomas da brusone?. A brusone ocorre também nos colmos. Quando a planta fica mais vulnerável à doença?. Como a brusone nas folhas entra na lavoura? Quais as fontes de inóculo?. Quais são as fontes de inóculo para a brusone nas panículas?. Fique em alerta para evitar as seguintes situações. Como a brusone entra e se desenvolve na planta?. Quais as condições climáticas que favorecem o desenvolvimento da brusone?. O que favorece o desenvolvimento da brusone?. Quais são os danos causados pela brusone?. Como reduzir os danos causados pela brusone?. Quais as práticas culturais que podem ajudar a controlar a brusone?. Como a escolha de diferentes cultivares pode diminuir a severidade da doença?. Controle químico: tão importante quanto o fungicida é o momento da aplicação. Como escolher um fungicida?. Algumas recomendações que podem ser seguidas. Em curto prazo. Em médio prazo. Em longo prazo.bitstream/item/134931/1/CNPAF-2015-brusone.pdfE-book

Characterization and quantification of postharvest losses of apple fruit stored under commercial conditions.

The objectives of this study were to characterize and quantify postharvest losses of apples under commercial conditions in Santa Catarina state, Brazil. Two experiments were conducted using ?Gala? and ?Fuji? apples. The first experiment was to characterize and quantify the most important causes of loss of fruit treated or not treated with 1-methylcyclopropene (1-MCP) then held in controlled atmosphere (CA) storage. This experiment was conducted in commercial storage facilities from 2007 to 2010. In each year, 10 samples of ≈380 kg each for ?Gala? and 400 kg each for ?Fuji? were collected from bins of commercially harvested fruit from each of 15 ?Gala? and 17 ?Fuji? orchards. Half of the samples from each orchard were treated with 1-MCP at harvest. Fruit were stored in CA, at 0.7 °C, for 150 to 300 days. After storage, one subsample of 100 disorder-free apples were selected from each sample and held at 22 °C for 7 days to simulate shelf-life conditions. The fruit were analyzed after CA storage and shelf life for the incidence of disorders. The second experiment was conducted in 2011 to identify the main fungi causing decay during storage. In this study, apples were stored in 10 commercial CA storage rooms at 0.7 °C for 180 to 240 days. After storage, fruit with decay symptoms were collected at the commercial sorting line. A total of 10 samples of 100 decayed apples were taken throughout the sorting period for each cultivar and storage room. The fungal decays were identified by visual symptoms on each fruit. Total apple losses during storage varied from 3.9% to 12.1% for ?Gala? and 6.6% to 8.4% for ?Fuji?, depending on the year and 1-MCP treatment. During storage, deterioration caused by fungal decay was ≈60% and 80% of total losses for ?Gala? and ?Fuji?, respectively. During shelf life, additional losses caused by fungal decay ranged from 8.4% to 17.6% for ?Gala? and 12.4% to 27.2% for ?Fuji?, depending on the year. Senescent breakdown and superficial scald were the major physiological disorders. 1-MCP treatment had no effect on losses due to decay. Bull?s-eye rot, blue mold, gray mold, and alternaria rot were the most prevalent fungal decay symptoms, accounting for 52%, 27%, 9% and 10% of ?Gala? losses and 42%, 25%, 18% and 5% of ?Fuji? losses, respectively. Sources of variability for losses among years and orchards is discussed

Scope and Mechanistic Study of the Coupling Reaction of α,β-Unsaturated Carbonyl Compounds with Alkenes: Uncovering Electronic Effects on Alkene Insertion vs Oxidative Coupling Pathways

The cationic ruthenium-hydride complex [(C6H6)(PCy3)(CO)RuH]+BF4– (1) was found to be a highly effective catalyst for the intermolecular conjugate addition of simple alkenes to α,β-unsaturated carbonyl compounds to give (Z)-selective tetrasubstituted olefin products. The analogous coupling reaction of cinnamides with electron-deficient olefins led to the oxidative coupling of two olefinic C–H bonds in forming (E)-selective diene products. The intramolecular version of the coupling reaction efficiently produced indene and bicyclic fulvene derivatives. The empirical rate law for the coupling reaction of ethyl cinnamate with propene was determined as follows: rate = k[1]1[propene]0[cinnamate]−1. A negligible deuterium kinetic isotope effect (kH/kD = 1.1 ± 0.1) was measured from both (E)-C6H5CH═C(CH3)CONHCH3 and (E)-C6H5CD═C(CH3)CONHCH3 with styrene. In contrast, a significant normal isotope effect (kH/kD = 1.7 ± 0.1) was observed from the reaction of (E)-C6H5CH═C(CH3)CONHCH3 with styrene and styrene-d8. A pronounced carbon isotope effect was measured from the coupling reaction of (E)-C6H5CH═CHCO2Et with propene (13C(recovered)/13C(virgin) at Cβ = 1.019(6)), while a negligible carbon isotope effect (13C(recovered)/13C(virgin) at Cβ = 0.999(4)) was obtained from the reaction of (E)-C6H5CH═C(CH3)CONHCH3 with styrene. Hammett plots from the correlation of para-substituted p-X-C6H4CH═CHCO2Et (X = OCH3, CH3, H, F, Cl, CO2Me, CF3) with propene and from the treatment of (E)-C6H5CH═CHCO2Et with a series of para-substituted styrenes p-Y-C6H4CH═CH2 (Y = OCH3, CH3, H, F, Cl, CF3) gave the positive slopes for both cases (ρ = +1.1 ± 0.1 and +1.5 ± 0.1, respectively). Eyring analysis of the coupling reaction led to the thermodynamic parameters, ΔH⧧ = 20 ± 2 kcal mol–1 and ΔS⧧ = −42 ± 5 eu. Two separate mechanistic pathways for the coupling reaction have been proposed on the basis of these kinetic and spectroscopic studies

Storability of 'SCS417 Monalisa' apple as affected by harvest maturity, 1-methylcyclopropene treatment, and storage atmosphere.

The objective of this work was to determine the storability of 'SCS417 Monalisa' apple fruit in response to harvest maturity, 1-methylcyclopropene (1-MCP) treatment, and storage atmospheres. Fruit quality was evaluated after two, four, six, and eight months plus one day or seven days in shelf life at 22°C. The controlled atmosphere (CA) and 1-MCP (1.0 ?L L-1) treatments reduce fruit ethylene production and respiration, prevent rapid softening, and inhibit the incidence of scald-like symptoms, flesh browning, cracking, and fungal decay, in comparison with air storage . The combination of 1-MCP and CA provides additive benefits in firmness retention and in the reduction of the incidence of physiological disorders. CA and/or 1-MCP increase the risk of fruit developing wrinkly skin disorder. The loss of flesh firmness and acidity and the development of all physiological disorders and decay are higher in late-harvested fruit. The storage life of 'SCS417 Monalisa' apple is about two months in cold air and from six to eight months in cold CA, considering the time necessary to reach a flesh firmness of 53 N. The limiting factor for the long-term storage of 'SCS417 Monalisa' apple fruit under CA without 1-MCP is the development of physiological disorders and fungal decay

Development of high-throughput methods to screen disease caused by Rhizoctonia solani AG 2-1 in oilseed rape

Background: Rhizoctonia solani (Kühn) is a soil-borne, necrotrophic fungus causing damping off, root rot and stem canker in many cultivated plants worldwide. Oilseed rape (OSR, Brassica napus) is the primary host for anastomosis group (AG) 2-1 of R. solani causing pre- and post-emergence damping-off resulting in death of seedlings and impaired crop establishment. Presently, there are no known resistant OSR genotypes and the main methods for disease control are fungicide seed treatments and cultural practices. The identification of sources of resistance for crop breeding is essential for sustainable management of the disease. However, a high-throughput, reliable screening method for resistance traits is required. The aim of this work was to develop a low cost, rapid screening method for disease phenotyping and identification of resistance traits. Results: Four growth systems were developed and tested: (1) nutrient media plates, (2) compost trays, (3) light expanded clay aggregate (LECA) trays, and (4) a hydroponic pouch and wick system. Seedlings were inoculated with virulent AG 2-1 to cause damping-off disease and grown for a period of 4–10 days. Visual disease assessments were carried out or disease was estimated through image analysis using ImageJ. Conclusion: Inoculation of LECA was the most suitable method for phenotyping disease caused by R. solani AG 2-1 as it enabled the detection of differences in disease severity among OSR genotypes within a short time period whilst allowing measurements to be conducted on whole plants. This system is expected to facilitate identification of resistant germplasm

Resistência de cultivares de cafeeiro a cercosporiose.

A presente pesquisa teve como objetivo verificar a resistência de seis cultivares de cafeeiro à cercosporiose

Widespread DNA hypomethylation at gene enhancer regions in placentas associated with early-onset pre-eclampsia.

Pre-eclampsia is a serious complication of pregnancy that can affect both maternal and fetal outcomes. Early-onset pre-eclampsia (EOPET) is a severe form of pre-eclampsia that is associated with altered physiological characteristics and gene expression in the placenta. DNA methylation is a relatively stable epigenetic modification to DNA that can reflect gene expression, and can provide insight into the mechanisms underlying such expression changes. This case-control study focused on DNA methylation and gene expression of whole chorionic villi samples from 20 EOPET placentas and 20 gestational age-matched controls from pre-term births. DNA methylation was also assessed in placentas affected by late-onset pre-eclampsia (LOPET) and normotensive intrauterine growth restriction (nIUGR). The Illumina HumanMethylation450 BeadChip was used to assess DNA methylation at >480 000 cytosine-guanine dinucleotide (CpG) sites. The Illumina HT-12v4 Expression BeadChip was used to assess gene expression of >45 000 transcripts in a subset of cases and controls. DNA methylation analysis by pyrosequencing was used to follow-up the initial findings in four genes with a larger cohort of cases and controls, including nIUGR and LOPET placentas. Bioinformatic analysis was used to identify overrepresentation of gene ontology categories and transcription factor binding motifs. We identified 38 840 CpG sites with significant (false discovery rate 12.5% methylation difference compared with the controls. Significant sites were enriched at the enhancers and low CpG density regions of the associated genes and the majority (74.5%) of these sites were hypomethylated in EOPET. EOPET, but not associated clinical features, such as intrauterine growth restriction (IUGR), presented a distinct DNA methylation profile. CpG sites from four genes relevant to pre-eclampsia (INHBA, BHLHE40, SLC2A1 and ADAM12) showed different extent of changes in LOPET and nIUGR. Genome-wide expression in a subset of samples showed that some of the gene expression changes were negatively correlated with DNA methylation changes, particularly for genes that are responsible for angiogenesis (such as EPAS1 and FLT1). Results could be confounded by altered cell populations in abnormal placentas. Larger sample sizes are needed to fully address the possibility of sub-profiles of methylation within the EOPET cohort. Based on DNA methylation profiling, we conclude that there are widespread DNA methylation alterations in EOPET that may be associated with changes in placental function. This property may provide a useful tool for early screening of such placentas. This study identifies DNA methylation changes at many loci previously reported to have altered gene expression in EOPET placentas, as well as in novel biologically relevant genes we confirmed to be differentially expressed. These results may be useful for DNA- methylation-based non-invasive prenatal diagnosis of at-risk pregnancies

Estimating the delay between host infection and disease (incubation period) and assessing its significance to the epidemiology of plant diseases.

Knowledge of the incubation period of infectious diseases (time between host infection and expression of disease symptoms) is crucial to our epidemiological understanding and the design of appropriate prevention and control policies. Plant diseases cause substantial damage to agricultural and arboricultural systems, but there is still very little information about how the incubation period varies within host populations. In this paper, we focus on the incubation period of soilborne plant pathogens, which are difficult to detect as they spread and infect the hosts underground and above-ground symptoms occur considerably later. We conducted experiments on Rhizoctonia solani in sugar beet, as an example patho-system, and used modelling approaches to estimate the incubation period distribution and demonstrate the impact of differing estimations on our epidemiological understanding of plant diseases. We present measurements of the incubation period obtained in field conditions, fit alternative probability models to the data, and show that the incubation period distribution changes with host age. By simulating spatially-explicit epidemiological models with different incubation-period distributions, we study the conditions for a significant time lag between epidemics of cryptic infection and the associated epidemics of symptomatic disease. We examine the sensitivity of this lag to differing distributional assumptions about the incubation period (i.e. exponential versus Gamma). We demonstrate that accurate information about the incubation period distribution of a pathosystem can be critical in assessing the true scale of pathogen invasion behind early disease symptoms in the field; likewise, it can be central to model-based prediction of epidemic risk and evaluation of disease management strategies. Our results highlight that reliance on observation of disease symptoms can cause significant delay in detection of soil-borne pathogen epidemics and mislead practitioners and epidemiologists about the timing, extent, and viability of disease control measures for limiting economic loss.ML thanks the Institut Technique français de la Betterave industrielle (ITB) for funding this project. CAG and JANF were funded by the UK’s Biotechnology and Biological Sciences Research Council (BBSRC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

gp100/pmel17 and tyrosinase encode multiple epitopes recognized by Th1-type CD4+T cells

CD4+ T cells modulate the magnitude and durability of CTL responses in vivo, and may serve as effector cells in the tumour microenvironment. In order to identify the tumour epitopes recognized by tumour-reactive human CD4+ T cells, we combined the use of an HLA-DR4/peptide binding algorithm with an IFN-γ ELISPOT assay. Two known and three novel CD4+ T cell epitopes derived from the gp 100/pmel17 and tyrosinase melanocyte-associated antigens were confirmed or identified. Of major interest, we determined that freshly-isolated PBMC frequencies of Th1-type CD4+ T recognizing these peptides are frequently elevated in HLA-DR4+ melanoma patients (but not normal donors) that are currently disease-free as a result of therapeutic intervention. Epitope-specific CD4+ T cells from normal DR4+ donors could be induced, however, after in vitro stimulation with autologous dendritic cell pulsed with antigens (peptides or antigen-positive melanoma lysates) or infected with recombinant vaccinia virus encoding the relevant antigen. Peptide-reactive CD4+ T cells also recognized HLA-DR4+ melanoma cell lines that constitutively express the relevant antigen. Based on these data, these epitopes may serve as potent vaccine components to promote clinically-relevant Th1-type CD4+ T cell effector function in situ. http://www.bjcancer.com © 2001 Cancer Research Campaig

O2-Filled Swimbladder Employs Monocarboxylate Transporters for the Generation of O2 by Lactate-Induced Root Effect Hemoglobin

The swimbladder volume is regulated by O2 transfer between the luminal space and the blood In the swimbladder, lactic acid generation by anaerobic glycolysis in the gas gland epithelial cells and its recycling through the rete mirabile bundles of countercurrent capillaries are essential for local blood acidification and oxygen liberation from hemoglobin by the “Root effect.” While O2 generation is critical for fish flotation, the molecular mechanism of the secretion and recycling of lactic acid in this critical process is not clear. To clarify molecules that are involved in the blood acidification and visualize the route of lactic acid movement, we analyzed the expression of 17 members of the H+/monocarboxylate transporter (MCT) family in the fugu genome and found that only MCT1b and MCT4b are highly expressed in the fugu swimbladder. Electrophysiological analyses demonstrated that MCT1b is a high-affinity lactate transporter whereas MCT4b is a low-affinity/high-conductance lactate transporter. Immunohistochemistry demonstrated that (i) MCT4b expresses in gas gland cells together with the glycolytic enzyme GAPDH at high level and mediate lactic acid secretion by gas gland cells, and (ii) MCT1b expresses in arterial, but not venous, capillary endothelial cells in rete mirabile and mediates recycling of lactic acid in the rete mirabile by solute-specific transcellular transport. These results clarified the mechanism of the blood acidification in the swimbladder by spatially organized two lactic acid transporters MCT4b and MCT1b