267 research outputs found

    Fine Mapping of the SCN Resistance Locus \u3ci\u3erhg1-b\u3c/i\u3e from PI 88788

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    Soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) is the most economically damaging soybean [Glycine max (L.) Merr.] pest in the USA and genetic resistance is a key component for its control. Although SCN resistance is quantitative, the rhg1 locus on chromosome 18 (formerly known as Linkage Group G) confers a high level of resistance. The objective of this study was to fi ne-map the rhg1-b allele that is derived from plant introduction (PI) 88788. F2 and F3 plants and F3:4 lines from crosses between SCN resistant and susceptible genotypes were tested with genetic markers to identify recombination events close to rhg1-b. Lines developed from these recombinant plants were then tested for resistance to the SCN isolate PA3, which originally had an HG type 0 phenotype, and with genetic markers. Analysis of lines carrying key recombination events positioned rhg1-b between the simple sequence repeat (SSR) markers BARCSOYSSR_18_0090 and BARCSOYSSR_18_0094. This places rhg1-b to a 67-kb region of the ‘Williams 82’ genome sequence. The receptor-like kinase gene that has been previously identified as a candidate for the ‘Peking’-derived SCN resistant rhg1 gene is adjacent to, but outside of, the rhg1-b interval defined in the present study

    Editor’s Essay: Moving beyond Western Corporate Perspectives: On the Need to Increase the Diversity of Risk and Crisis Communication Research

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    The field of crisis and risk communication research has experienced significant growth and increasing institutionalization in the past decades. However, there are still geographic and perspective blind spots. Up to date, by far the most research focuses on the U.S.; non-Western perspectives remain marginal. Moreover, the focus on organizational crises still clearly dominates. We therefore call for more research better reflecting the global environment and diverse crisis and risk contexts in which our field can make contributions. This argument is supported by the current pandemic mandating cross-cultural and multi-perspective approaches

    Editorial Essay: A Reflection on Methodological Diversity in the Journal of International Crisis and Risk Communication Research

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    This is the Editor's essay for Volume 5, Issue 1 of the Journal of International Crisis and Risk Communication Research

    A nematode demographics assay in transgenic roots reveals no significant impacts of the Rhg1 locus LRR-Kinase on soybean cyst nematode resistance

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    <p>Abstract</p> <p>Background</p> <p>Soybean cyst nematode (<it>Heterodera glycines</it>, SCN) is the most economically damaging pathogen of soybean (<it>Glycine max</it>) in the U.S. The <it>Rhg1 </it>locus is repeatedly observed as the quantitative trait locus with the greatest impact on SCN resistance. The Glyma18g02680.1 gene at the <it>Rhg1 </it>locus that encodes an apparent leucine-rich repeat transmembrane receptor-kinase (LRR-kinase) has been proposed to be the SCN resistance gene, but its function has not been confirmed. Generation of fertile transgenic soybean lines is difficult but methods have been published that test SCN resistance in transgenic roots generated with <it>Agrobacterium rhizogenes</it>.</p> <p>Results</p> <p>We report use of artificial microRNA (amiRNA) for gene silencing in soybean, refinements to transgenic root SCN resistance assays, and functional tests of the <it>Rhg1 </it>locus LRR-kinase gene. A nematode demographics assay monitored infecting nematode populations for their progress through developmental stages two weeks after inoculation, as a metric for SCN resistance. Significant differences were observed between resistant and susceptible control genotypes. Introduction of the <it>Rhg1 </it>locus LRR-kinase gene (genomic promoter/coding region/terminator; Peking/PI 437654-derived SCN-resistant source), into <it>rhg1</it><sup>- </sup>SCN-susceptible plant lines carrying the resistant-source <it>Rhg4</it><sup><it>+ </it></sup>locus, provided no significant increases in SCN resistance. Use of amiRNA to reduce expression of the LRR-kinase gene from the <it>Rhg1 </it>locus of Fayette (PI 88788 source of <it>Rhg1</it>) also did not detectably alter resistance to SCN. However, silencing of the LRR-kinase gene did have impacts on root development.</p> <p>Conclusion</p> <p>The nematode demographics assay can expedite testing of transgenic roots for SCN resistance. amiRNAs and the pSM103 vector that drives interchangeable amiRNA constructs through a soybean polyubiqutin promoter (Gmubi), with an intron-GFP marker for detection of transgenic roots, may have widespread use in legume biology. Studies in which expression of the <it>Rhg1 </it>locus LRR-kinase gene from different resistance sources was either reduced or complemented did not reveal significant impacts on SCN resistance.</p

    Extending the rapeseed gene pool with resynthesized Brassica napus II: Heterosis

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    Hybrid breeding relies on the combination of parents from two differing heterotic groups. However, the genetic diversity in adapted oilseed rape breeding material is rather limited. Therefore, the use of resynthesized Brassica napus as a distant gene pool was investigated. Hybrids were derived from crosses between 44 resynthesized lines with a diverse genetic background and two male sterile winter oilseed rape tester lines. The hybrids were evaluated together with their parents and check cultivars in 2 years and five locations in Germany. Yield, plant height, seed oil, and protein content were monitored, and genetic distances were estimated with molecular markers (127 polymorphic RFLP fragments). Resynthesized lines varied in yield between 40.9 dt/ha and 21.5 dt/ha, or between 85.1 and 44.6% of check cultivar yields. Relative to check cultivars, hybrids varied from 91.6 to 116.6% in yield and from 94.5 to 103.3% in seed oil content. Mid-parent heterosis varied from −3.5 to 47.2% for yield. The genetic distance of parental lines was not significantly correlated with heterosis or hybrid yield. Although resynthesized lines do not meet the elite rapeseed standards, they are a valuable source for hybrid breeding due to their large distance from present breeding material and their high heterosis when combined with European winter oilseed rape

    Identifying nurses' rewards: a qualitative categorization study in Belgium

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    BACKGROUND: Rewards are important in attracting, motivating and retaining the most qualified employees, and nurses are no exception to this rule. This makes the establishment of an efficient reward system for nurses a true challenge for every hospital manager. A reward does not necessarily have a financial connotation: non-financial rewards may matter too, or may even be more important. Therefore, the present study examines nurses' reward perceptions, in order to identify potential reward options. METHODS: To answer the research question "What do nurses consider a reward and how can these rewards be categorized?", 20 in-depth semi-structured interviews with nurses were conducted and analysed using discourse and content analyses. In addition, the respondents received a list of 34 rewards (derived from the literature) and were asked to indicate the extent to which they perceived each of them to be rewarding. RESULTS: Discourse analysis revealed three major reward categories: financial, non-financial and psychological, each containing different subcategories. In general, nurses more often mentioned financial rewards spontaneously in the interview, compared to non-financial and psychological rewards. The questionnaire results did not, however, indicate a significant difference in the rewarding potential of these three categories. Both the qualitative and quantitative data revealed that a number of psychological and non-financial rewards were important for nurses in addition to their monthly pay and other remunerations. In particular, appreciation for their work by others, compliments from others, presents from others and contact with patients were highly valued. Moreover, some demographical variables influenced the reward perceptions. Younger and less experienced nurses considered promotion possibilities as more rewarding than the older and more senior ones. The latter valued job security and working for a hospital with a good reputation higher than their younger and more junior colleagues. CONCLUSION: When trying to establish an efficient reward system for nurses, hospital managers should not concentrate on the financial reward possibilities alone. They also ought to consider non-financial and psychological rewards (in combination with financial rewards), since nurses value these as well and they may lead to a more personalized reward system

    Differential Effects of Painful and Non-Painful Stimulation on Tactile Processing in Fibromyalgia Syndrome and Subjects with Masochistic Behaviour

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    BACKGROUND: In healthy subjects repeated tactile stimulation in a conditioning test stimulation paradigm yields attenuation of primary (S1) and secondary (S2) somatosensory cortical activation, whereas a preceding painful stimulus results in facilitation. METHODOLOGY/PRINCIPAL FINDINGS: Since previous data suggest that cognitive processes might affect somatosensory processing in S1, the present study aims at investigating to what extent cortical reactivity is altered by the subjective estimation of pain. To this end, the effect of painful and tactile stimulation on processing of subsequently applied tactile stimuli was investigated in patients with fibromyalgia syndrome (FMS) and in subjects with masochistic behaviour (MB) by means of a 122-channel whole-head magnetoencephalography (MEG) system. Ten patients fulfilling the criteria for the diagnosis of FMS, 10 subjects with MB and 20 control subjects matched with respect to age, gender and handedness participated in the present study. Tactile or brief painful cutaneous laser stimuli were applied as conditioning stimulus (CS) followed by a tactile test stimulus (TS) 500 ms later. While in FMS patients significant attenuation following conditioning tactile stimulation was evident, no facilitation following painful stimulation was found. By contrast, in subjects with MB no attenuation but significant facilitation occurred. Attenuation as well as facilitation applied to cortical responses occurring at about 70 ms but not to early S1 or S2 responses. Additionally, in FMS patients the amount of attenuation was inversely correlated with catastrophizing tendency. CONCLUSION: The present results imply altered cortical reactivity of the primary somatosensory cortex in FMS patients and MB possibly reflecting differences of individual pain experience
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