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1.
BJPsych Bull ; 47(4): 235-241, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35300744

RESUMO

AIMS AND METHOD: The authors designed and delivered simulation training to improve the confidence and competence of junior doctors beginning work in psychiatry. Junior doctors completed various simulated psychiatry scenarios while receiving personalised feedback and teaching from their peers in online or socially distanced settings. Learners rated their confidence in psychiatry skills pre- and post-session, and Wilcoxon signed-rank tests were conducted to detect statistically significant differences. Qualitative feedback was analysed thematically. RESULTS: Twenty-one junior doctors attended the training. There were statistically significant (P < 0.05) improvements in trainee confidence across all psychiatry skills tested. The most enjoyable aspects of the session included its 'interactivity', relevance to clinical practice, and 'realistic' and 'interesting' simulated scenarios. CLINICAL IMPLICATIONS: Near-peer simulation teaching, delivered both in person and online, is effective at improving junior doctors' confidence in psychiatry. Delivering this training during placement induction could help to ensure adequate preparation of, and support for, new doctors.

2.
Food Energy Secur ; 12(4): e475, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38439908

RESUMO

The efficient preservation of protein in silage for livestock feed is dependent on the rate and extent of proteolysis. Previous research on fresh forage indicated enhanced protein stability in certain Festulolium (ryegrass × fescue hybrids) cultivars compared to ryegrass. This is the first report of an experiment to test the hypothesis that a Lolium perenne × Festuca arundinacea var glaucescens cultivar had reduced proteolysis compared to perennial ryegrass (L. perenne) during the ensiling process. Forages were harvested in May (Cut 2) and August (Cut 4), wilted for 24 h and ensiled in laboratory-scale silos. Silage was destructively sampled at 0 h, 9 h, 24 h, 48 h, 72 h, 14 days and 90 days post-ensiling, and dry matter (DM), pH and chemical composition were determined. At Cut 2, there was no difference in crude protein between treatments but ryegrass had higher soluble nitrogen (SN) (P < 0.001) and grass × time interactions (p = 0.03) indicated higher rates of proteolysis. By Cut 4, Festulolium had (5.5% units) higher CP than ryegrass (p < 0.001) but SN did not differ. Ammonia-N did not differ between silages in either cut. DM differences (11.8% units) between treatments in Cut 4 (v.2.2% in Cut 2) may have masked effects on proteolysis, highlighting the importance of management on silage quality. This was despite higher WSC in ryegrass in both cuts (p < 0.001), with grass × time interactions (Cut 2; p = 0.03) showing slower WSC decline in ryegrass in Cut 4 (p < 0.001). Silage pH values did not differ between grasses in either cut, but grass × time interactions (p < 0.001) showed a slower decline in both ryegrass cuts, resulting in higher (p < 0.05) pH at 24 h and 72 h for Cuts 2 and 4, respectively. Overall, the hypothesis for an enhanced protein stability in Festulolium when ensiled as ruminant feed was evidenced by lower SN but not ammonia-N in an early-cut silage with a comparable DM to ryegrass.

3.
Foods ; 10(10)2021 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-34681405

RESUMO

The extent to which the quality and yield of plant varieties are influenced by the environment is important for their successful uptake by end users particularly as climatic fluctuations are resulting in environments that are highly variable from one growing season to another. The genotype-by-environment interaction (GEI) of milling quality and yield was studied using four winter oat varieties in multi-locational trials over 4 years in the U.K. Significant differences across the 22 environments were found between physical grain quality and composition as well as grain yield, with the environment having a significant effect on all of the traits measured. Grain yield was closely related to grain number m-2 whereas milling quality traits were related to grain size attributes. Considerable genotype by environment interaction was obtained for all grain quality traits and stability analysis revealed that the variety Mascani was the least sensitive to the environment for all milling quality traits measured whereas the variety Balado was the most sensitive. Examination of environmental conditions at specific within-year stages of crop development indicated that both temperature and rainfall during grain development were correlated with grain yield and ß-glucan content and with the ease of removing the hull (hullability).

5.
Influenza Other Respir Viruses ; 15(6): 813-823, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34081398

RESUMO

BACKGROUND: Standard-dose seasonal influenza vaccines often produce modest immunogenic responses in adults ≥65 years old. MF59 is intended to elicit a greater magnitude and increased breadth of immune response. OBJECTIVE: To determine the effectiveness of seasonal MF59-adjuvanted trivalent/quadrivalent influenza vaccine (aTIV/aQIV) relative to no vaccination or vaccination with standard or high-dose egg-based influenza vaccines among people ≥65 years old. METHODS: Cochrane methodological standards and PRISMA-P guidelines were followed. Real-world evidence from non-interventional studies published in peer-reviewed journals and gray literature from 1997 through to July 15, 2020, including cluster-randomized trials, were eligible. Two reviewers independently extracted data; risk of bias was assessed using the ROBINS-I tool. RESULTS: Twenty-one studies conducted during the 2006/07-2019/20 influenza seasons were included in the qualitative review; 16 in the meta-analyses. Meta-analysis of test-negative studies found that aTIV reduced medical encounters due to lab-confirmed influenza with pooled estimates of 40.7% (95% CI: 21.9, 54.9; I2  = 0%) for non-emergency outpatient visits and 58.5% (40.7, 70.9; I2  = 52.9%) for hospitalized patients. The pooled estimate of VE from case-control studies was 51.3% (39.1, 61.1; I2  = 0%) against influenza- or pneumonia-related hospitalization. The pooled estimates for the relative VE of aTIV for the prevention of influenza-related medical encounters were 13.9% (4.2, 23.5; I2  = 95.9%) compared with TIV, 13.7% (3.1, 24.2; I2  = 98.8%) compared with QIV, and 2.8% (-2.9, 8.5; I2  = 94.5%) compared with HD-TIV. CONCLUSIONS: Among adults ≥65 years, aTIV demonstrated significant absolute VE, improved relative VE compared to non-adjuvanted standard-dose TIV/QIV, and comparable relative VE to high-dose TIV.


Assuntos
Vacinas contra Influenza , Influenza Humana , Adjuvantes Imunológicos , Adulto , Idoso , Humanos , Influenza Humana/prevenção & controle , Polissorbatos , Estações do Ano , Esqualeno
6.
Animals (Basel) ; 11(4)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918882

RESUMO

Gas production profiles typically show a monotonically increasing monophasic pattern. However, atypical gas production profiles exist whereby at least two consecutive phases of gas production or additional extraneous features that distort the typical profile are present. Such profiles are more likely to occur with the use of a fecal inoculum and are much less well described. The presence of multiple phases or non-descript extraneous features makes it difficult to apply directly recommended modeling approaches such as standard response functions or classical growth functions. To overcome such difficulties, extensions of the Mitscherlich equation and a numerical modeling option also based on the Mitscherlich are explored. The numerical modeling option uses an estimate of relative rate obtained from the smoothed data profile and an estimate of maximum gas produced together with any lag time information drawn from the raw data to construct a simple Mitscherlich equation. In summary, this article illustrates the analysis of atypical gas production profiles obtained using a fecal inoculum and explores the methodology of numerical modeling to reconstruct equivalent typical growth-like trends.

7.
Microorganisms ; 8(11)2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33187375

RESUMO

Anaerobic fungi in the gut of domesticated and wild mammalian herbivores play a key role in the host's ability to utilize plant biomass. Due to their highly effective ability to enzymatically degrade lignocellulose, anaerobic fungi are biotechnologically interesting. Numerous factors have been shown to affect the ability of anaerobic fungi to break down plant biomass. However, methods to reduce the non-productive lag time in batch cultures and the effect of leaf-blade cut-length and condition on the fungal fermentation are not known. Therefore, experimentation using a novel gas production approach with pre-grown, axenic cultures of Neocallimastix frontalis was performed using both fresh and air-dried perennial ryegrass leaf-blades of different cut-lengths. The methodology adopted removed the lag-phase and demonstrated the digestion of un-autoclaved leaf-blades. Fermentation of leaf-blades of 4.0 cm cut-length produced 18.4% more gas yet retained 11.2% more apparent DM relative to 0.5 cm cut-length leaf-blades. Drying did not affect fermentation by N. frontalis, although an interaction between drying and leaf-blade cut-length was noted. Removal of the lag phase and the use of un-autoclaved substrates are important when considering the biotechnological potential of anaerobic fungi. A hypothesis based upon sporulation at cut surfaces is proposed to describe the experimental results.

8.
Food Energy Secur ; 9(3): e227, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32999718

RESUMO

The increasing frequency of droughts and floods on grasslands, due to climate change, increases the risk of soil compaction. Soil compaction affects both soil and forage productivity. Differing grasses may counteract some effects of compaction due to differences in their root architecture and ontogeny. To compare their resilience to soil compaction, three Festulolium (ryegrass and fescue species' hybrids) forage grass cultivars comprising differing root architecture and ontogeny were compared in replicated field plots, together with a ryegrass and tall fescue variety as controls. Pre-compaction soil and forage properties were determined in spring using > four-year-old plots to generate baseline data. Half of each field plot was then artificially compacted using farm machinery. Forage dry matter yield (DMY) was determined over four cuts. After the final harvest, post compaction soil characteristics and root biomass (RB) were compared between grasses in the non-compacted and compacted soils. Pre-compaction data showed that soil under Festulolium and ryegrass had similar water infiltration rates, higher than soil under tall fescue plots. Tiller density of the Festulolium at this time was significantly higher than fescue but not the ryegrass control. Forage DMY was significantly lower (p < .001) with compacted soil at the first cut but, by the completion of the growing season, there was no effect of soil compaction on total DMY. Tall fescue had a higher total DMY than other grasses, which all produced similar annual yields. Soil bulk density and penetration resistance were higher, and grass tiller density was lower in compacted soils. Root biomass in compacted soils showed a tendency for Festulolium cv Lp × Fg to have higher RB than the ryegrass at 0-15 cm depth. Overall, findings showed alternative grass root structures provide differing resilience to machinery compaction, and root biomass production can be encouraged without negative impacts on forage productivity.

10.
Front Plant Sci ; 8: 563, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28469627

RESUMO

Miscanthus is a genus of perennial rhizomatous grasses with C4 photosynthesis which is indigenous in a wide geographic range of Asian climates. The sterile clone, Miscanthus × giganteus (M. × giganteus), is a naturally occurring interspecific hybrid that has been used commercially in Europe for biomass production for over a decade. Although, M. × giganteus has many outstanding performance characteristics including high yields and low nutrient offtakes, commercial expansion is limited by cloning rates, slow establishment to a mature yield, frost, and drought resistance. In this paper, we evaluate the performance of 13 novel germplasm types alongside M. × giganteus and horticultural "Goliath" in trials in six sites (in Germany, Russia, The Netherlands, Turkey, UK, and Ukraine). Mean annual yields across all the sites and genotypes increased from 2.3 ± 0.2 t dry matter ha-1 following the first year of growth, to 7.3 ± 0.3, 9.5 ± 0.3, and 10.5 ± 0.2 t dry matter ha-1 following the second, third, and fourth years, respectively. The highest average annual yields across locations and four growth seasons were observed for M. × giganteus (9.9 ± 0.7 t dry matter ha-1) and interspecies hybrid OPM-6 (9.4 ± 0.6 t dry matter ha-1). The best of the new hybrid genotypes yielded similarly to M. × giganteus at most of the locations. Significant effects of the year of growth, location, species, genotype, and interplay between these factors have been observed demonstrating strong genotype × environment interactions. The highest yields were recorded in Ukraine. Time needed for the crop establishment varied depending on climate: in colder climates such as Russia the crop has not achieved its peak yield by the fourth year, whereas in the hot climate of Turkey and under irrigation the yields were already high in the first growing season. We have identified several alternatives to M. × giganteus which have provided stable yields across wide climatic ranges, mostly interspecies hybrids, and also Miscanthus genotypes providing high biomass yields at specific geographic locations. Seed-propagated interspecific and intraspecific hybrids, with high stable yields and cheaper reliable scalable establishment remain a key strategic objective for breeders.

11.
PLoS One ; 9(5): e97516, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24830777

RESUMO

Alternative forages can be used to provide valuable home-grown feed for ruminant livestock. Utilising these different forages could affect the manure value and the implications of incorporating these forages into farming systems, needs to be better understood. An experiment tested the hypothesis that applying slurries from ruminants, fed ensiled red clover (Trifolium pratense), lucerne (Medicago sativa) or kale (Brassica oleracea) would improve the yield of hybrid ryegrass (Lolium hybridicum), compared with applying slurries from ruminants fed ensiled hybrid ryegrass, or applying inorganic N alone. Slurries from sheep offered one of four silages were applied to ryegrass plots (at 35 t ha⁻¹) with 100 kg N ha⁻¹ inorganic fertiliser; dry matter (DM) yield was compared to plots only receiving ammonium nitrate at rates of 0, 100 and 250 kg N ha⁻¹ year-1. The DM yield of plots treated with 250 kg N, lucerne or red clover slurry was significantly higher than other treatments (P<0.001). The estimated relative fertiliser N equivalence (FNE) (fertiliser-N needed to produce same yield as slurry N), was greatest for lucerne (114 kg) >red clover (81 kg) >kale (44 kg) >ryegrass (26 kg ha⁻¹ yr⁻¹). These FNE values represent relative efficiencies of 22% (ryegrass), 52% (kale), 47% (red clover) and 60% for lucerne slurry, with the ryegrass slurry efficiency being lowest (P = 0.005). Soil magnesium levels in plots treated with legume slurry were higher than other treatments (P<0.001). Overall, slurries from ruminants fed alternative ensiled forages increased soil nutrient status, forage productivity and better N efficiency than slurries from ruminants fed ryegrass silage. The efficiency of fertiliser use is one of the major factors influencing the sustainability of farming systems, these findings highlight the cascade in benefits from feeding ruminants alternative forages, and the need to ensure their value is effectively captured to reduce environmental risks.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Lolium , Silagem/análise , Trifolium , Agricultura , Criação de Animais Domésticos , Animais , Brassica , Meio Ambiente , Fertilizantes , Medicago sativa , Nitratos/química , Nitrogênio/química , Ruminantes , Ovinos , Solo
12.
PLoS One ; 9(1): e86259, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24489708

RESUMO

An experiment investigated whether the inclusion of chicory (Cichorium intybus) in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne). Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36) were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC) determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011 in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.


Assuntos
Lolium , Ração Animal , Criação de Animais Domésticos , Animais , Bovinos , Cichorium intybus , Carne , Contagem de Ovos de Parasitas , Aumento de Peso
13.
Plant Biotechnol J ; 11(5): 572-81, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23331642

RESUMO

Perennial ryegrass (Lolium perenne L.) is the most important forage crop in temperate livestock agriculture. Its nutritional quality has significant impact on the quality of meat and milk for human consumption. Evidence suggests that higher energy content in forage can assist in reducing greenhouse gas emissions from ruminants. Increasing the fatty acid content (especially α-linolenic acid, an omega-3 fatty acid) may thus contribute to better forage, but little is known about the genetic basis of variation for this trait. To this end, quantitative trait loci (QTLs) were identified associated with major fatty acid content in perennial ryegrass using a population derived from a cross between the heterozygous and outbreeding high-sugar grass variety AberMagic and an older variety, Aurora. A genetic map with 434 restriction-associated DNA (RAD) and SSR markers was generated. Significant QTLs for the content of palmitic (C16:0) on linkage groups (LGs) 2 and 7; stearic (C18:0) on LGs 3, 4 and 7; linoleic (C18:2n-6) on LGs 2 and 5; and α-linolenic acids (C18:3n-3) on LG 1 were identified. Two candidate genes (a lipase and a beta-ketoacyl CoA synthase), both associated with C16:0, and separately with C18:2n-6 and C18:0 contents, were identified. The physical positions of these genes in rice and their genetic positions in perennial ryegrass were consistent with established syntenic relationships between these two species. Validation of these associations is required, but the utility of RAD markers for rapid generation of genetic maps and QTL analysis has been demonstrated for fatty acid composition in a global forage crop.


Assuntos
DNA de Plantas/genética , Ácidos Graxos/metabolismo , Técnicas de Genotipagem/métodos , Lolium/genética , Característica Quantitativa Herdável , Mapeamento por Restrição , Análise de Sequência de DNA , Sequência de Aminoácidos , Mapeamento Cromossômico , Cruzamentos Genéticos , Estudos de Associação Genética , Marcadores Genéticos , Humanos , Escore Lod , Repetições de Microssatélites/genética , Dados de Sequência Molecular , Fenótipo , Proteínas de Plantas/química , Locos de Características Quantitativas/genética , Estatísticas não Paramétricas
14.
Health Rep ; 22(3): 29-33, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22106787

RESUMO

BACKGROUND: In the fall of 2009, Canada undertook a mass vaccination campaign against pH1N1. This report provides an overview of self-reported pH1N1 vaccination coverage of the Ontario population, building on an existing random digit-dialling telephone survey, in which 9,010 Ontario adults participated. Based on the results, 34.5% of Ontario residents were vaccinated: 33.3% of adults aged 18 or older and 38.6% of children and adolescents younger than age 18. Respondents reporting high-risk chronic conditions were significantly more likely to report being vaccinated than were people who did not report such conditions. Determining vaccination uptake for the Ontario population is important in the evaluation of the province's pH1N1 prevention program.


Assuntos
Promoção da Saúde/métodos , Promoção da Saúde/estatística & dados numéricos , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza , Influenza Humana/prevenção & controle , Autorrelato , Adolescente , Adulto , Fatores Etários , Idoso , Criança , Pré-Escolar , Doença Crônica , Feminino , Inquéritos Epidemiológicos , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Ontário/epidemiologia , Estações do Ano , Fatores Sexuais , Vacinação , Adulto Jovem
15.
Artigo em Inglês | MEDLINE | ID: mdl-21622057

RESUMO

This paper presents an analytical modeling technique for the simulation of long-range ultrasonic guided waves in structures. The model may be used to predict the displacement field in a prismatic structure arising from any excitation arrangement and may therefore be used as a tool to design new inspection systems. It is computationally efficient and relatively simple to implement, yet gives accuracy similar to finite element analysis and semi-analytical finite element analysis methods. The model has many potential applications; one example is the optimization of part-circumferential arrays where access to the full circumference of the pipe is restricted. The model has been successfully validated by comparison with finite element solutions. Experimental validation has also been carried out using an array of piezoelectric transducer elements to measure the displacement field arising from a single transducer element in an 88.9-mm-diameter pipe. Good agreement has been obtained between the two models and the experimental data.

16.
Plant Physiol ; 155(2): 1013-22, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21115808

RESUMO

The Arabidopsis (Arabidopsis thaliana) FLOWERING LOCUS T (FT) gene and its orthologs in other plant species (e.g. rice [Oryza sativa] OsFTL2/Hd3a) have an established role in the photoperiodic induction of flowering response. The genomic and phenotypic variations associated with the perennial ryegrass (Lolium perenne) ortholog of FT, designated LpFT3, was assessed in a diverse collection of nine European germplasm populations, which together constituted an association panel of 864 plants. Sequencing and genotyping of a series of amplicons derived from the nine populations, containing the complete exon and intron sequences as well as 5' and 3' noncoding sequences of LpFT3, identified a total of seven haplotypes. Genotyping assays designed to detect the genomic variation showed that three haplotypes were present in approximately equal proportions and represented 84% of the total, with a fourth representing a further 11%. Of the three major haplotypes, two were predicted to code for identical protein products and the third contained two amino acid substitutions. Association analysis using either a mixed model with a relationship matrix to correct for population structure and relatedness or structured association with further correction using genomic control indicated significant associations between LpFT3 and variation in flowering time. These associations were corroborated in a validation population segregating for the same major alleles. The most "diagnostic" region of genomic variation was situated 5' of the coding sequence. Analysis of this region identified that the interhaplotype variation was closely associated with sequence motifs that were apparently conserved in the 5' region of orthologs of LpFT3 from other plant species. These may represent cis-regulatory elements involved in influencing the expression of this gene.


Assuntos
Flores/fisiologia , Variação Genética , Lolium/genética , Proteínas de Plantas/metabolismo , Alelos , Proteínas de Arabidopsis , DNA de Plantas/genética , Éxons , Flores/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Haplótipos , Íntrons , Lolium/metabolismo , Proteínas de Plantas/genética , Análise de Sequência de DNA
17.
Phytopathology ; 100(1): 21-32, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19968546

RESUMO

Hypersensitive response (HR) against Blumeria graminis f. sp. hordei infection in barley (Hordeum vulgare) was associated with stomata "lock-up" leading to increased leaf water conductance (g(l)). Unique spatio-temporal patterns of HR formation occurred in barley with Mla1, Mla3, or MlLa R genes challenged with B. graminis f. sp. hordei. With Mla1, a rapid HR, limited to epidermal cells, arrested fungal growth before colonies initiated secondary attacks. With Mla3, mesophyll HR preceded that in epidermal cells whose initial survival supported secondary infections. With MlLa, mesophyll survived and not all attacked epidermal cells died immediately, allowing colony growth and secondary infection until arrested. Isolines with Mla1, Mla3, or MlLa genes inoculated with B. graminis f. sp. hordei ranging from 1 to 100 conidia mm(2) showed abnormally high g(l) during dark periods whose timing and extent correlated with those of each HR. Each isoline showed increased dark g(l) with the nonpathogen B. graminis f. sp. avenae which caused a single epidermal cell HR. Guard cell autofluorescence was seen only after drying of epidermal strips and closure of stomata suggesting that locked open stomata were viable. The data link stomatal lock-up to HR associated cell death and has implications for strategies for selecting disease resistant genotypes.


Assuntos
Ascomicetos/fisiologia , Morte Celular/fisiologia , Hordeum/microbiologia , Hordeum/fisiologia , Folhas de Planta/fisiologia , Ascomicetos/crescimento & desenvolvimento , Ascomicetos/ultraestrutura , Regulação da Expressão Gênica de Plantas , Hordeum/ultraestrutura , Microscopia Eletrônica de Varredura , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Água/metabolismo
18.
Genetics ; 177(1): 535-47, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17660575

RESUMO

We describe a candidate gene approach for associating SNPs with variation in flowering time and water-soluble carbohydrate (WSC) content and other quality traits in the temperate forage grass species Lolium perenne. Three analysis methods were used, which took the significant population structure into account. First, a linear mixed model was used enabling a structured association analysis to be incorporated with the nine populations identified in the structure analysis as random variables. Second, a within-population analysis of variance was performed. Third, a tree-scanning method was used, in which haplotype trees were associated with phenotypes on the basis of inferred haplotypes. Analysis of variance within populations identified several associations between WSC, nitrogen (N), and dry matter digestibility with allelic variants within an alkaline invertase candidate gene LpcAI. These associations were only detected in material harvested in one of the two years. By contrast, consistent associations between the L. perenne homolog (LpHD1) of the rice photoperiod control gene HD1 and flowering time were identified. One SNP, in the immediate upstream region of the LpHD1 coding sequence (C-4443-A), was significant in the linear mixed model. Within-population analysis of variance and tree-scanning analysis confirmed and extended this result to the 2118 polymorphisms in some of the populations. The merits of the tree-scanning method are compared to the single SNP analysis. The potential usefulness of the 4443 SNP in marker-assisted selection is currently being evaluated in test crosses of genotypes from this work with turf-grass varieties.


Assuntos
Carboidratos/análise , Flores/crescimento & desenvolvimento , Genes de Plantas/genética , Lolium/genética , Polimorfismo de Nucleotídeo Único , DNA de Plantas/genética , Frequência do Gene , Marcadores Genéticos , Genética Populacional , Haplótipos/genética , Dados de Sequência Molecular , Fenótipo
19.
Mol Plant Pathol ; 6(1): 65-78, 2005 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-20565639

RESUMO

SUMMARY Nonspecific penetration resistance due to papilla formation and race-specific hypersensitive response (HR) can both contribute to Blumeria graminis resistance in barley. Some effective papillae form even in the susceptible cv. Pallas and the isoline P01 carries the additional Mla1 allele conditioning HR. The NO-specific stain DAF-2DA (4,5-diaminofluorescein-2-diacetate) revealed a transient NO generation burst commencing 10 h after inoculation (h.a.i.) in close association with sites of papilla formation in both barley lines. In P01 a burst of NO production throughout some attacked cells was initiated around 10-12 h.a.i. and this preceded whole-cell autofluorescence indicative of HR. The specificity of DAF-2DA staining was demonstrated by the suppression of staining following application of the NO scavenger C-PTIO (1H-imidazol-1-yloxy-2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-3-oxide). In addition, C-PTIO application increased penetration frequencies in both barley lines, indicating a role for NO in papilla-based resistance. Furthermore, C-PTIO application slightly delayed HR in P01 whereas, conversely, application of an NO donor, sodium nitroprusside, slightly accelerated HR in P01 and increased cell death frequency in Pallas. Thus, NO generation is one of the earliest responses of barley epidermal cell defence against B. graminis attack and may be important in both the initiation and the development of effective papillae and cell death due to HR.

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