1,519 research outputs found

    Effects of Cultivar and Maternal Environment on Seed Quality in \u3cem\u3eVicia sativa\u3c/em\u3e

    Get PDF
    Production of high quality seeds is of fundamental importance for successful crop production. However, knowledge of the effects of increased temperature resulting from global warming on seed quality of alpine species is limited. We investigated the effect of maternal environment on seed quality of three cultivars of the leguminous forage species Vicia sativa, giving particular attention to temperature. Plants of each cultivar were grown at 1700 and 3000 m a.s.l., and mass, germination, electrical conductivity (EC) of leakage and longevity were determined for mature seeds. Seeds of all three cultivars produced at the low elevation had a significantly lower mass and longevity but higher EC of leachate than those produced at the high elevation, suggesting that increased temperatures decreased seed quality. However, seed viability did not differ between elevations. The effects of maternal environment on seed germination strongly depended on cultivar and germination temperature. At 10 and 15°C, seeds of “Lanjian 3” produced at high elevation germinated to higher percentages and rates than those produced at low elevation, but the opposite trend was observed at 20°C. However, for seeds of “Lanjian 1” and “Lanjian 2,” no significant effect of elevation was observed in germination percentage. Our results indicate that the best environment for the production of high quality seeds (e.g., high seed mass, low EC, high seed longevity) of V. sativa is one in which temperatures are relatively low during seed development

    Efficacy and safety of acupuncture for depression: A systematic review and meta-analysis

    Get PDF
    Acupuncture is widely accepted as a therapeutic option for managing depression. However, evidence from clinical trials remains controversial. This review aims to synthesize the best available evidence on the efficacy and safety of acupuncture in managing depression. The review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Five databases and the relevant trial registries were searched from the inception to October 2021. Randomized clinical trials of acupuncture for managing depression, published in English, were selected for inclusion. The quality of included studies was assessed using the Cochrane risk of bias tool. Netmeta and dmetar of R packages were used to conduct a network meta-analysis. Twenty-two trials with 2391 participants were eligible and included in the analysis. This review found evidence that electroacupuncture (EA) plus antidepressant achieved superior outcomes compared with the waitlist (standardized mean difference = −8.86, 95% confidence interval: −14.78 to −2.93). The treatment ranking of different interventions in improving depression symptoms indicated that EA plus antidepressant with a probability of 0.8294, followed by manual acupuncture (MA) plus antidepressant (0.6470) and MA (0.5232). Acupuncture, either in isolation or as an adjunct to pharmacological treatment, has clinical benefits and can be considered a safe option for managing depression

    Effects of Increased Precipitation on the Life History of Spring- and Autumn-Germinated Plants of the Cold Desert Annual \u3cem\u3eErodium oxyrhynchum\u3c/em\u3e (Geraniaceae)

    Get PDF
    Future increased precipitation in cold desert ecosystems may impact annual/ephemeral plant species that germinate in both spring and autumn. Our primary aim was to compare the life history characteristics of plants from spring-germinating (SG) and autumn-germinating (AG) seeds of Erodium oxyrhynchum. Plants in field plots with simulated increases in precipitation of 0, 30 and 50 % in spring and summer were monitored to determine seedling survival, phenology, plant size, seed production and biomass accumulation and allocation. Germination characteristics were determined in the laboratory for seeds produced by plants in all increased precipitation treatments. Increased precipitation in spring significantly improved survival of seedlings from SG and AG seeds, but survival was less for AG than SG. An increase in precipitation increased the number of seeds per plant for both SG and AG, but AG produced more seeds per plant than SG. With increased precipitation, percentage of dormant seeds from SG increased significantly, while that of AG decreased slightly. Our study suggests that with increased spring and summer rainfall AG will produce an increased number of nondormant seeds that could germinate in autumn and SG an increased number of dormant seeds that become part of the soil seed bank. However, ability of some seeds to germinate in autumn and others in spring will be maintained as long as soil moisture is limited in autumn

    Comparison of Thermal and Hydrotime Requirements for Seed Germination of Seven \u3cem\u3eStipa\u3c/em\u3e Species from Cool and Warm Habitats

    Get PDF
    Temperature and water potential are two important environmental factors influencing germination and subsequent seedling establishment. Seed germination requirements vary with species and with the environment in which the seeds are produced. Stipa species dominate large areas of the Eurasian zonal vegetation, but comparisons of germination requirements between Stipa species from different habitats is limited. We investigated the effects of temperature and water potential on seed germination of S. grandis, S. purpurea, and S. penicillata from habitats with low temperatures and relatively abundant rainfall (cool habitats) and S. glareosa, S. breviflora, S. gobiea, and S. bungeana from habitats with relatively high temperatures and low amount of rainfall (warm habitats). Seeds of species from cool habitats had a higher base (Tb), optimal (To), and maximum (Tc) temperature than those of species from warm habitats, except for the base temperature of S. purpurea. Response of six tested Stipa species to water potential differed among species but not between habitats. Median water potential for germination was lowest for S. bungeana, S. penicillata, and S. gobiea. There was a negative correlation between hydrotime constant (ΞH) and base water potential for 50% of the seeds of all species to germinate (ψb(50)). Germination time of seven Stipa species in response to temperature and water was well predicted by thermal time and hydrotime models. Results of the present study on germination of these seven species of Stipa may provide useful suggestions for grassland restoration in different habitats

    Accumulation of heavy metals in food web components across a gradient of lakes

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109770/1/lno20004571525.pd

    Definition, conservation and epigenetics of housekeeping and tissue-enriched genes

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Housekeeping genes (HKG) are constitutively expressed in all tissues while tissue-enriched genes (TEG) are expressed at a much higher level in a single tissue type than in others. HKGs serve as valuable experimental controls in gene and protein expression experiments, while TEGs tend to represent distinct physiological processes and are frequently candidates for biomarkers or drug targets. The genomic features of these two groups of genes expressed in opposing patterns may shed light on the mechanisms by which cells maintain basic and tissue-specific functions.</p> <p>Results</p> <p>Here, we generate gene expression profiles of 42 normal human tissues on custom high-density microarrays to systematically identify 1,522 HKGs and 975 TEGs and compile a small subset of 20 housekeeping genes which are highly expressed in all tissues with lower variance than many commonly used HKGs. Cross-species comparison shows that both the functions and expression patterns of HKGs are conserved. TEGs are enriched with respect to both segmental duplication and copy number variation, while no such enrichment is observed for HKGs, suggesting the high expression of HKGs are not due to high copy numbers. Analysis of genomic and epigenetic features of HKGs and TEGs reveals that the high expression of HKGs across different tissues is associated with decreased nucleosome occupancy at the transcription start site as indicated by enhanced DNase hypersensitivity. Additionally, we systematically and quantitatively demonstrated that the CpG islands' enrichment in HKGs transcription start sites (TSS) and their depletion in TEGs TSS. Histone methylation patterns differ significantly between HKGs and TEGs, suggesting that methylation contributes to the differential expression patterns as well.</p> <p>Conclusion</p> <p>We have compiled a set of high quality HKGs that should provide higher and more consistent expression when used as references in laboratory experiments than currently used HKGs. The comparison of genomic features between HKGs and TEGs shows that HKGs are more conserved than TEGs in terms of functions, expression pattern and polymorphisms. In addition, our results identify chromatin structure and epigenetic features of HKGs and TEGs that are likely to play an important role in regulating their strikingly different expression patterns.</p
    • 

    corecore