RESUMO
The Oregon Wolfe Barley mapping population is a resource for genetics research and instruction. Prior reports are based on a population of doubled haploid (DH) lines developed by the Hordeum bulbosum (H.b.) method, which samples female gametes. We developed new DH lines from the same cross using anther culture (A.C.), which samples male gametes. Linkage maps were generated in each of the two subpopulations using the same 1,328 single nucleotide polymorphism markers. The linkage maps based on DH lines derived from the products of megasporogeneis and microsporogenesis revealed minor differences in terms of estimated recombination rates. There were no differences in locus ordering. There was greater segregation distortion in the A.C.-derived subpopulation than in the H.b.-derived subpopulation, but in the region showing the greatest distortion, the cause was more likely allelic variation at the ZEO1 plant height locus rather than to DH production method. The effects of segregation distortion and pleiotropy had greater impacts on estimates of quantitative trait locus effect than population size for reproductive fitness traits assayed under greenhouse conditions. The Oregon Wolfe Barley (OWB) population and data are community resources. Seed is available from three distribution centers located in North America, Europe, and Asia. Details on ordering seed sets, as well as complete genotype and phenotype data files, are available at http://wheat.pw.usda.gov/ggpages/maps/OWB/ .
Assuntos
Mapeamento Cromossômico , Células Germinativas Vegetais/fisiologia , Haploidia , Hordeum/genética , Alelos , Ásia , Cromossomos de Plantas , Hibridização Genômica Comparativa , Europa (Continente) , Ligação Genética , Genótipo , América do Norte , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Sementes/genéticaRESUMO
The development of winter malting barley (Hordeum vulgare L.) varieties is emerging as a worldwide priority due to the numerous advantages of these varieties over spring types. However, the complexity of both malting quality and winter hardiness phenotypes makes simultaneous improvement a challenge. To obtain an understanding of the relationship between loci controlling winter hardiness and malt quality and to assess the potential for breeding winter malting barley varieties, we structurally and functionally characterized the six-row accession "88Ab536", a cold-tolerant line with superior malting quality characteristics that derives from the cross of NE76129/Morex//Morex. We used 4,596 SNPs to construct the haplotype structure of 88Ab536 on which malting quality and winter hardiness loci reported in the literature were aligned. The genomic regions determining malting quality and winter hardiness traits have been defined in this founder germplasm, which will assist breeders in targeting regions for marker-assisted selection. The Barley1 GeneChip array was used to functionally characterize 88Ab536 during malting. Its gene expression profile was similar to that of the archetypical malting variety Morex, which is consistent with their similar malting quality characteristics. The characterization of 88Ab536 has increased our understanding of the genetic relationships of malting quality and winter hardiness, and will provide a genetic foundation for further development of more cold-tolerant varieties that have malt quality characteristics that meet or exceed current benchmarks.
Assuntos
Produtos Agrícolas , Cruzamentos Genéticos , Hordeum/genética , Estações do Ano , Mapeamento Cromossômico , Cromossomos de Plantas , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/genética , Marcadores Genéticos , Haplótipos , Hordeum/anatomia & histologia , Fenótipo , Locos de Características QuantitativasRESUMO
Phenotypic plasticity is the variation in phenotypic traits produced by a genotype in different environments. In contrast, environmental canalization is defined as the insensitivity of a genotype's phenotype to variation in environments. Despite the extensive literature on the evolutionary significance and potential genetic mechanisms driving plasticity and canalization, few studies tried to unravel the genetic basis of this phenomenon. Using both simulations and real data from barley (Hordeum vulgare), we used QTL mapping to obtain insights into the genetics of phenotypic plasticity. We explored two ways of quantifying phenotypic plasticity, namely the phenotypic variance across environments and the Finlay-Wilkinson's regression slope. Each relates to a different concept of stability. Through QTL detection with real and simulated data, we show that each measure of plasticity detects specific types of plasticity QTL. Most of the plasticity QTLs were detected in the data set with the lowest number of environments. All plasticity QTL co-located with loci showing QTL x E interaction and there were no QTL that only affected plasticity. The number of environments that are considered and their homogeneity is a key to interpret the genetic control of phenotypic plasticity. Regulatory pathways of plasticity may vary from one set of environments to another due to unique features of each environment. Therefore, with an increasing number of environments, it may become impossible to detect a single 'consistent' regulatory pathway for all environments.
Assuntos
Hordeum/genética , Locos de Características Quantitativas , Biodiversidade , Mapeamento Cromossômico , Variação Genética , Genótipo , FenótipoRESUMO
The effects of synchronous photo (16 h daylength) and thermo (2 degrees C daily fluctuation) cycles on flowering time were compared with constant light and temperature treatments using two barley mapping populations derived from the facultative cultivar 'Dicktoo'. The 'Dicktoo'x'Morex' (spring) population (DM) segregates for functional differences in alleles of candidate genes for VRN-H1, VRN-H3, PPD-H1, and PPD-H2. The first two loci are associated with the vernalization response and the latter two with photoperiod sensitivity. The 'Dicktoo'x'Kompolti korai' (winter) population (DK) has a known functional polymorphism only at VRN-H2, a locus associated with vernalization sensitivity. Flowering time in both populations was accelerated when there was no fluctuating factor in the environment and was delayed to the greatest extent with the application of synchronous photo and thermo cycles. Alleles at VRN-H1, VRN-H2, PPD-H1, and PPD-H2--and their interactions--were found to be significant determinants of the increase/decrease in days to flower. Under synchronous photo and thermo cycles, plants with the Dicktoo (recessive) VRN-H1 allele flowered significantly later than those with the Kompolti korai (recessive) or Morex (dominant) VRN-H1 alleles. The Dicktoo VRN-H1 allele, together with the late-flowering allele at PPD-H1 and PPD-H2, led to the greatest delay. The application of synchronous photo and thermo cycles changed the epistatic interaction between VRN-H2 and VRN-H1: plants with Dicktoo type VRN-H1 flowered late, regardless of the allele phase at VRN-H2. Our results are novel in demonstrating the large effects of minor variations in environmental signals on flowering time: for example, a 2 degrees C thermo cycle caused a delay in flowering time of 70 d as compared to a constant temperature.
Assuntos
Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Hordeum/fisiologia , Proteínas de Plantas/metabolismo , Cruzamentos Genéticos , Flores/genética , Genótipo , Hordeum/genética , Luz , Fenótipo , Proteínas de Plantas/genética , TemperaturaRESUMO
ABSTRACT Spot blotch, caused by Cochliobolus sativus, is an important disease of barley in many production areas and is best controlled through the deployment of resistant cultivars. Information on the genetics of resistance in various sources can be useful in developing effective breeding strategies. Parents of the doubled haploid mapping population Calicuchima-sib/ Bowman-BC (C/B) exhibit a differential reaction to pathotypes 1 and 2 of C. sativus. To elucidate the genetics of spot blotch resistance in this population, C/B progeny were evaluated with both pathotypes at the seedling stage in the greenhouse and at the adult plant stage in the field. At the seedling stage, progeny segregated 84 resistant to 26 susceptible based on the qualitative analysis of infection response (IR) data to pathotype 1. This fit best to a 3:1 ratio, indicating that two genes were involved in conferring resistance. Quantitative analysis of the raw IR data to pathotype 1 revealed a single quantitative trait locus (QTL) on chromosome 4(4H) explaining 14% of the phenotypic variance. Adult plant resistance to pathotype 1 was conferred by QTL on chromosome 2(2H) and chromosome 3(3H), explaining 21 and 32% of the phenotypic variation, respectively. Bowman contributed the resistance alleles on chromosome 3(3H) and chromosome 4(4H), whereas Calicuchima-sib contributed the resistance allele on chromosome 2(2H). Resistance to pathotype 2 was conferred by a single gene (designated Rcs6) on chromosome 5(1H) based on qualitative analysis of data. Rcs6 was effective at both the seedling and adult plant stages and was contributed by Calicuchima-sib. This result was corroborated in the quantitative analysis of raw IR (seedling stage) and disease severity (adult plant stage) data as a single major effect (r(2) = 0.93 and 0.88, respectively) QTL was identified on chromosome 5(1H). Progeny with resistance to both pathotypes were identified in the C/B population and may be useful in programs breeding for spot blotch resistance.
RESUMO
An interval on barley (Hordeum vulgare L.) chromosome 7 accounting for significant quantitative trait locus effects for winter hardiness were detected in a winter (Dicktoo) x spring (Morex) barley population (P.M. Hayes, T. Blake, T.H.H. Chen, S. Tragoonrung, F. Chen, A. Pan, and B. Liu [1993] Genome 36: 66-71). Two members of the barley dehydrin gene family, Dhn1 and Dhn2, were located within the region defining the winter hardiness quantitative trait locus effect (A. Pan, P.M. Hayes, F. Chen, T. Blake, T.H.H. Chen, T.T.S. Wright, I. Karsai, Z. Bedo [1994] Theor Appl Genet 89: 900-910). To investigate the possible role of Dhn1 and Dhn2 in winter hardiness, we examined the expression pattern of six barley dehydrin gene family members in shoot tissue in response to cold temperature. Incubation of 3-week-old barley plants at 2[deg]C resulted in a rapid induction of a single 86-kD polypeptide that was recognized by an antiserum against a peptide conserved in the dehydrin gene family. Northern blot analysis confirmed the induction of an mRNA corresponding to Dhn5. The expression patterns of cold-induced dehydrins in shoot tissue for Dicktoo and Morex were identical under the conditions studied, in spite of the known phenotypic differences in their winter hardiness. These results, together with the allelic structure of selected high- and low-survival lines, suggest that the Dicktoo alleles at the Dhn1 and Dhn2 may not be the primary determinants of winter hardiness in barley.
RESUMO
The plasma protein beta2-glycoprotein I (beta2-GPI) is a major target of autoantibodies in patients with the antiphospholipid syndrome. To understand the physiological function of beta2-GPI and its potential role in the pathophysiology of the antiphospholipid syndrome, the binding of beta2-GPI to phospholipid membranes was characterized. The interaction of beta2-GPI with unilamellar vesicles containing varying amounts of acidic phospholipids with phosphatidylcholine (PC) was measured at equilibrium via relative light scattering. Analysis of binding isotherms gave apparent Kd values ranging from approximately 5.0 to 0.5 microM over a range of 5-20 mol % anionic phospholipid. Inhibition of binding by increasing ionic strength and Ca2+ ions suggests that binding is primarily electrostatic. These data indicate that beta2-GPI binding to membranes with physiological anionic phospholipid content is relatively weak in comparison to plasma coagulation proteins, suggesting that beta2-GPI does not function as a physiological anticoagulant based on its phospholipid-binding properties.
Assuntos
Glicoproteínas/química , Fosfolipídeos/química , Humanos , Membranas Artificiais , Ligação Proteica , beta 2-Glicoproteína IRESUMO
While evaluating a professional practice model, serendipitous findings emerged from the data regarding non-nursing functions. Performing non-nursing functions and attitudes about doing so were significantly related to management data.
Assuntos
Descrição de Cargo , Modelos de Enfermagem , Cuidados de Enfermagem/organização & administração , Atitude do Pessoal de Saúde , Humanos , Satisfação no Emprego , Pesquisa em Administração de Enfermagem , Recursos Humanos de Enfermagem Hospitalar/organização & administração , Recursos Humanos de Enfermagem Hospitalar/psicologia , Carga de TrabalhoRESUMO
Winterhardiness in cereals is the consequence of a number of complex and interacting components: cold tolerance, vernalization requirement and photoperiod sensitivity. An understanding of the genetic basis of these component traits should allow for more effective selection. Genome map-based analyses hold considerable promise for dissecting complex phenotypes. A 74-point linkage map was developed from one hundred double haploid lines derived from a winter x spring barley cross and used as the basis for quantitative trait locus (QTL) analyses to determine the chromosome location of genes controlling components of winterhardiness. Despite the greater genome coverage provided by the current map, a previously-reported interval on chromosome 7 remains the only region where significant QTL effects for winter survival were detected in this population. QTLs for heading date under 24 h light map to the same region. A QTL for heading date under this photoperiod regime also maps to chromosome 2. A distinct set of QTLs mapping to chromosomes 1, 2, 3 and 5 determined heading date under 8 h light. Patterns of differential QTL expression underscore the complexity of Winterhardiness.
Assuntos
Hordeum/genética , Hordeum/fisiologia , Aclimatação/genética , Mapeamento Cromossômico , Clima Frio , Genes de Plantas , Ligação Genética , Hordeum/crescimento & desenvolvimento , Fenótipo , Estações do AnoRESUMO
To identify work-related relationships, team building sessions were established with registered nurses and nurse's aides. Within these groups, expectations and philosophies were communicated and resulted in mutual respect and understanding.
Assuntos
Assistentes de Enfermagem/organização & administração , Equipe de Enfermagem/organização & administração , Humanos , Relações InterprofissionaisRESUMO
A phalloplasty using the pedicled anterolateral thigh flap in three patients with aphallia is described. The technique, its advantages and disadvantages are discussed.
Assuntos
Órgãos Artificiais , Pênis/anormalidades , Pênis/lesões , Procedimentos de Cirurgia Plástica/métodos , Retalhos Cirúrgicos/irrigação sanguínea , Adolescente , Queimaduras/cirurgia , Criança , Evolução Fatal , Identidade de Gênero , Humanos , Masculino , Pênis/cirurgia , Coxa da Perna/cirurgia , Coleta de Tecidos e Órgãos/métodos , Resultado do Tratamento , Adulto JovemRESUMO
Quantitative resistance (QR) to disease is usually more durable than qualitative resistance, but its genetic basis is not well understood. We used the barley/barley stripe rust pathosystem as a model for the characterization of the QR phenotype and associated genomic regions. As an intermediate step in the preparation of near-isogenic lines representing individual QTL alleles and combinations of QTL alleles in a homogeneous genetic background, we developed a set of QTL introgression lines in a susceptible background. These intermediate barley near-isogenic (i-BISON) lines represent disease resistance QTL combined in one-, two-, and three-way combinations in a susceptible background. We measured four components of disease resistance on the i-BISON lines: latent period, infection efficiency, lesion size, and pustule density. The greatest differences between the target QTL introgressions and the susceptible controls were for the latter three traits. On average, however, the QTL introgressions also had longer latent periods than the susceptible parent (Baronesse). There were significant differences in the magnitudes of effects of different QTL alleles. The 4H QTL allele had the largest effect, followed by the alleles on 1H and 5H. Pyramiding multiple QTL alleles led to higher levels of resistance in terms of all components of QR except latent period.
Assuntos
Hordeum/genética , Doenças das Plantas/genética , Locos de Características Quantitativas , Alelos , Análise de Variância , Basidiomycota/fisiologia , Hordeum/microbiologia , FenótipoRESUMO
Winterhardiness has three primary components: photoperiod (day length) sensitivity, vernalization response, and low temperature tolerance. Photoperiod and vernalization regulate the vegetative to reproductive phase transition, and photoperiod regulates expression of key vernalization genes. Using two barley mapping populations, we mapped six individual photoperiod response QTL and determined their positional relationship to the phytochrome and cryptochrome photoreceptor gene families and the vernalization regulatory genes HvBM5A, ZCCT-H, and HvVRT-2. Of the six photoreceptors mapped in the current study (HvPhyA and HvPhyB to 4HS, HvPhyC to 5HL, HvCry1a and HvCry2 to 6HS, and HvCry1b to 2HL), only HvPhyC coincided with a photoperiod response QTL. We recently mapped the candidate genes for the 5HL VRN-H1 (HvBM5A) and 4HL VRN-H2 (ZCCT-H) loci, and in this study, we mapped HvVRT-2, the barley TaVRT-2 ortholog (a wheat flowering repressor regulated by vernalization and photoperiod) to 7HS. Each of these three vernalization genes is located in chromosome regions determining small photoperiod response QTL effects. HvBM5A and HvPhyC are closely linked on 5HL and therefore are currently both positional candidates for the same photoperiod effect. The coincidence of photoperiod-responsive vernalization genes with photoperiod QTL suggests vernalization genes should also be considered candidates for photoperiod effects.
Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Hordeum/genética , Complexo de Proteínas do Centro de Reação Fotossintética , Locos de Características Quantitativas , Alelos , Mapeamento Cromossômico , Cromossomos de Plantas , Genoma de Planta , FotoperíodoRESUMO
Spot blotch, caused by Cochliobolus sativus, is an important disease of barley in the Upper Midwest region of the United States. The resistance of six-rowed malting cultivars like Morex has remained effective for over 40 years and is considered durable. Previous research on Steptoe/Morex (S/M), a 6x6-rowed doubled haploid (DH) population, showed that seedling resistance is controlled by a single gene (Rcs5) on chromosome 1(7H) and adult plant resistance by two quantitative trait loci (QTL): one of the major effect on chromosome 5(1H) explaining 62% of the phenotypic variance and a second of minor effect on chromosome 1(7H) explaining 9% of the phenotypic variance. To corroborate these results in a 2x6-rowed DH population, composite interval mapping (CIM) was performed on Harrington/Morex (H/M). As in the S/M population, a single major gene (presumably Rcs5) on chromosome 1(7H) conferred resistance at the seedling stage. However, at the adult plant stage, the results were markedly different as no chromosome 5(1H) effect whatsoever was detected. Instead, a QTL at or near Rcs5 on chromosome 1(7H) explained nearly all of the phenotypic variance (75%) for disease severity. To determine whether this result might be due to the genetic background of the two-rowed susceptible parent Harrington, we analyzed another DH population that included the same resistance donor (Morex) and another six-rowed susceptible cultivar Dicktoo (D/M). Three QTL conferred seedling resistance in the D/M population: one near Rcs5 on chromosome 1(7H) explaining 30%, a second near the centromere of chromosome 1(7H) explaining 9%, and a third on the short arm of chromosome 3(3H) explaining 19% of the phenotypic variation. As in the H/M population, no chromosome 5(1H) QTL was detected for adult plant resistance in the D/M population. Instead, three QTL on other chromosomes explained most of the variation: one on the short arm of chromosome 3(3H) explaining 36%, a second on the long arm of chromosome 3(3H) explaining 11%, and a third at or near Rcs5 on chromosome 1(7H) explaining 20% of the phenotypic variation. These data demonstrate the complexity of expression of spot blotch resistance in different populations and have important implications in breeding for durable resistance.
Assuntos
Ascomicetos , Hordeum/genética , Imunidade Inata/genética , Doenças das Plantas/microbiologia , Locos de Características Quantitativas/genética , Plântula/metabolismo , Cruzamento/métodos , Mapeamento Cromossômico , Doenças das Plantas/genética , Plântula/genética , Especificidade da EspécieRESUMO
With the aim of dissecting the genetic determinants of flowering time, vernalization response, and photoperiod sensitivity, we mapped the candidate genes for Vrn-H2 and Vrn-H1 in a facultative x winter barley mapping population and determined their relationships with flowering time and vernalization via QTL analysis. The Vrn-H2 candidate ZCCT-H genes were completely missing from the facultative parent and present in the winter barley parent. This gene was the major determinant of flowering time under long photoperiods in controlled environment experiments, irrespective of vernalization, and under spring-sown field experiments. It was the sole determinant of vernalization response, but the effect of the deletion was modulated by photoperiods when the vernalization requirement was fulfilled. There was no effect under short photoperiods. The Vrn-H1 candidate gene (HvBM5A) was mapped based on a microsatellite polymorphism we identified in the promoter of this gene. Otherwise, the HvBM5A alleles for the two parents were identical. Therefore, the significant flowering time QTL effect associated with this locus suggests tight linkage rather than pleiotropy. This QTL effect was smaller in magnitude than those associated with the Vrn-H2 locus and was significant in two-way interactions with Vrn-H2. The Vrn-H1 locus had no effect on vernalization response. Our results support the Vrn-H2/Vrn-H1 repressor/structural gene model for vernalization response in barley and suggest that photoperiod may also affect the Vrn genes or tightly linked loci.
Assuntos
Mapeamento Cromossômico , Flores/fisiologia , Genes de Plantas/genética , Hordeum/genética , Fenótipo , Locos de Características Quantitativas , Cruzamentos Genéticos , Flores/genética , Genótipo , Hordeum/fisiologia , Repetições de Microssatélites/genética , Fotoperíodo , Estações do AnoRESUMO
The limited population sizes used in many quantitative trait locus (QTL) detection experiments can lead to underestimation of QTL number, overestimation of QTL effects, and failure to quantify QTL interactions. We used the barley/barley stripe rust pathosystem to evaluate the effect of population size on the estimation of QTL parameters. We generated a large (n = 409) population of doubled haploid lines derived from the cross of two inbred lines, BCD47 and Baronesse. This population was evaluated for barley stripe rust severity in the Toluca Valley, Mexico, and in Washington State, USA, under field conditions. BCD47 was the principal donor of resistance QTL alleles, but the susceptible parent also contributed some resistance alleles. The major QTL, located on the long arm of chromosome 4H, close to the Mlo gene, accounted for up to 34% of the phenotypic variance. Subpopulations of different sizes were generated using three methods-resampling, selective genotyping, and selective phenotyping-to evaluate the effect of population size on the estimation of QTL parameters. In all cases, the number of QTL detected increased with population size. QTL with large effects were detected even in small populations, but QTL with small effects were detected only by increasing population size. Selective genotyping and/or selective phenotyping approaches could be effective strategies for reducing the costs associated with conducting QTL analysis in large populations. The method of choice will depend on the relative costs of genotyping versus phenotyping.
Assuntos
Basidiomycota , Mapeamento Cromossômico/métodos , Hordeum/genética , Imunidade Inata/genética , Doenças das Plantas/microbiologia , Densidade Demográfica , Locos de Características Quantitativas , Análise de Variância , Cruzamento/métodos , Cruzamentos Genéticos , México , Doenças das Plantas/genética , WashingtonRESUMO
With management and group dynamics education, peer and administrative support, and clear expectations, RNs can manage NAs. Without these supports, NAs may deliver the kind of care they see fit. Unfortunately, NAs have not been educated, socialized, or licensed into the nursing profession and do not necessarily hold the same values of quality of care that professional RNs hold. Older consumers in nursing homes deserve no less.