sampling strategy

抽样策略
  • 文章类型: Journal Article
    岩骨含有比任何其他人类骨骼高得多的DNA量。由于具有高度破坏性的采样,并且由于它并不总是回收的遗骸的一部分,DNA的替代来源的需要是重要的。要确定其他最佳骨骼类型,岩骨与股骨相比,塔利,和calcanei从两个不同的现代基督教墓地的66个成人骨骼中取样。采用完全去矿质的提取方法用于获得DNA,实时PCR定量以确定DNA数量和降解,和商业法医短串联重复序列(STR)PCR扩增试剂盒,以确定遗传概况。进行统计分析以探索DNA产量的差异,DNA降解,以及STR扩增的成功。很少有系统的研究探索DNA保存中骨骼内的变异性,包括不同时间段和地理位置不同的挖掘地点,调查的第二部分是基于两个考古遗址的比较,这使我们能够比较不同的死后间隔和环境条件对DNA保存的影响。errnomelj的较旧墓地在13至18世纪之间活跃,而最近的Polje墓葬在16至19世纪使用,创造不同的时间和地理环境。errnomelj埋葬地点的结果表明,岩骨的表现优于所有其他研究的骨类型,除了跟骨.在波列考古遗址Calcanei,塔利,股骨的STR分型成功率与岩骨相同。获得的结果强调了仔细选择骨骼样本对老化骨骼遗骸的DNA分析的重要性。除了岩骨,当调查较旧的墓地时,发现calcanei是DNA的替代来源。当最近的墓地被处理时,calcanei,塔利,除了岩骨之外,还应该对股骨进行采样,不仅因为它们表现良好,而且还因为在小梁骨的情况下更容易取样和更容易研磨。这项研究为各种骨骼类型作为DNA来源的潜在用途提供了宝贵的见解,用于研究老化的骨骼遗骸。它为法医和考古调查提供了实际意义。
    The petrous bone contains significantly higher amounts of DNA than any other human bone. Because of highly destructive sampling and because it is not always part of the recovered remains, the need for alternative sources of DNA is important. To identify additional optimal bone types, petrous bones were compared to femurs, tali, and calcanei sampled from 66 adult skeletons from two distinct modern-era Christian cemeteries. An extraction method employing full demineralization was used to obtain DNA, real-time PCR quantification to ascertain DNA quantity and degradation, and a commercial forensic short tandem repeats (STR) PCR amplification kit to determine genetic profiles. Statistical analysis was performed to explore the differences in DNA yield, DNA degradation, and success of STR amplification. A systematic studies exploring intra-skeletal variability in DNA preservation including various excavation sites differing by time period and geographical position are rare, and the second part of the investigation was based on a comparison of both archaeological sites, which allowed us to compare the effect of different post-mortem intervals and environmental conditions on DNA preservation. The older burial site in Črnomelj was active between the 13th and 18th century, whereas the more recent Polje burial was in use from the 16th to 19th century, creating different temporal and geographical environments. Results for the Črnomelj burial site revealed that the petrous bone outperformed all other bone types studied, except the calcaneus. At the Polje archeological site calcanei, tali, and femurs yielded the same STR typing success as petrous bones. The results obtained highlight the importance of careful bone sample selection for DNA analysis of aged skeletal remains. In addition to petrous bones, calcanei were found to be an alternative source of DNA when older burial sites are investigated. When more recent burial sites are processed, calcanei, tali, and femurs should be sampled besides petrous bones, not only because they exhibited good performance, but also because of easier sampling and easier grinding in the case of trabecular bones. This study contributes valuable insights into the potential use of various skeletal types as a source of DNA for investigation of aged skeletal remains, and it offers practical implications for forensic and archaeological investigations.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    有限的现场采样导致区域和全球湖泊二氧化碳(CO2)排放量估算存在重大不确定性。然而,区域湖泊CO2排放估算不确定性的定量分析仍不清楚。在这项研究中,我们利用卫星数据估算了中国东部113个湖泊的二氧化碳通量,揭示了流量的重大时空变化,平均18.07±81.83mgm-2d-1。此外,卫星估计的总CO2流出量表明,以前的升级研究高估了这些研究湖泊的总CO2流出量大约3-11倍,主要是由于湖泊二氧化碳通量的大幅变化。不足的采样分辨率导致了放大估计的相当大的不确定性。与二氧化碳的空间变化相比,二氧化碳的时间变化对放大不确定性的贡献更大。为了捕获湖泊CO2的动态,随着湖泊大小的减小和营养状态的增加,必须增加采样点和事件的数量。最后,我们提出了基于湖泊面积和营养状态的最佳采样分辨率预测,建议每个湖泊平均5点,每两个月采样一次,作为类似浅层富营养化湖泊的理想分辨率。这种方法已在北美和欧洲的湖泊中得到验证。我们认为,未来全球规模的湖泊碳预算估算将受益于在更合理的采样点和频率进行的实地观测。
    Limited field samplings result in significant uncertainties in regional and global estimates of lake carbon dioxide (CO2) emissions. However, quantitative analysis of uncertainty in regional lake CO2 emission estimates remains unclear. In this study, we utilized satellite data to estimate carbon dioxide flux from 113 eastern China lakes, revealing substantial spatial and temporal variations in flux, averaging 18.07 ± 81.83 mg m-2 d-1. Additionally, satellite-estimated total CO2 effluxes indicated previous upscaling studies had overestimated total CO2 effluxes from these studied lakes by approximately 3-11 times, primarily due to substantial variations in lake CO2 fluxes. Insufficient sampling resolution resulted in considerable uncertainty in upscaling estimations. Temporal variations in carbon dioxide contributed greater upscaling uncertainties than spatial variations in carbon dioxide. To capture the dynamics of lake CO2, increasing the number of sampling points and events is necessary as lake size decreases and trophic state increases. Finally, we propose a prediction for the optimal sampling resolution based on lake area and trophic state, recommending an average of 5 points per lake and bi-monthly sampling as the ideal resolution for similar shallow eutrophic lakes. This approach has been validated as effective in lakes across North America and Europe. We believe that future global-scale lake carbon budget estimates would benefit from field observations conducted at more reasonable sampling points and frequency.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    具有活跃期和空白期的与电弧有关的脉动凝血模式对于现代电外科至关重要。本文首先全面介绍了这种脉动模式,其次是实施方面的挑战。然后,工业规模的低速微控制器单元(MCU),TMS320F28379D,用于举例说明基于氮化镓(GaN)的高频逆变器上提出的输出采样和数据传输策略,该逆变器可实现具有交织的活动周期和空白周期的凝结模式。逆变器原型填充活动周期与幅度范围从数百到数千伏特的390kHz正弦波,同时在空白期间保持空输出。对上述正弦输出进行采样的策略,再加上直接内存访问(DMA)促进的数据传输,还明确表示用于后续功率计算。除此之外,一种新颖的非固定占空比方法,具有可变数量的正弦曲线作为活动周期,提出并集成到GaN基逆变器中以增强模式安全性。最后,该模式的功率跟踪性能最初是在电阻负载上评估的,其次是电阻加电容负载(R-C),第三,在新鲜的生物组织上出现电弧。本文最后研究了空空期的现有必要性。
    The arcing-involved pulsating coagulation mode with both active and blank periods is essential for modern electrosurgery. This paper begins with a comprehensive introduction to such a pulsating mode, followed by its implementation challenges. Then, an industrial-scale low-speed microcontroller unit (MCU), TMS320F28379D, is utilized to exemplify the proposed output sampling and data-transferring strategy on a gallium nitride (GaN)-based high-frequency inverter that enables coagulation mode with interweaved active periods and blank periods. The inverter prototype fills the active period with 390 kHz sinusoids of amplitude ranging from hundreds to thousands of Volts, while maintaining null outputs during blank periods. The strategy of sampling the above-mentioned sinusoidal outputs, coupled with their data transfer facilitated by direct memory access (DMA), is also articulated for subsequential power computation. Besides that, a novel nonfixed duty cycle approach, featuring an alterable number of sinusoids as the active period, is proposed and integrated into the GaN-based inverter to enhance mode safety. Finally, the power tracking performance of the mode is evaluated initially on resistive load, secondarily on resistive plus capacitive load (R-C), and thirdly on fresh biotissue with the appearance of electrical arcing. The existing necessity of the null blank periods is examined at the end of the paper.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    口腔中有多个细菌栖息地,真菌,病毒,和原生动物居住在,它们共同构成了口腔微生态系统。这些口腔中的微生物主要包括唾液,牙龈上牙菌斑,龈下牙菌斑,植入物周围的粘膜下斑块,牙菌斑在根管,和粘膜表面的斑块。微生物组的兴趣和知识随着技术的进步而动态地增加。因此,一个可靠的,可行,和口腔微生物组的实际采样策略是调查所必需的。本文介绍了口腔微生物的采样策略,包括样本收集,运输,processing,和存储。本研究涉及的材料和设备都是临床实践或实验室中常用的。本文所述抽样方法的可行性和可靠性已通过多个研究得到验证。
    There are multiple habitats in the oral cavity with bacteria, fungi, viruses, and protozoa residing in, which together constitute the oral micro-ecosystem. These microflorae in the oral cavity primarily include saliva, supragingival dental plaque, subgingival dental plaque, submucosal plaque around implants, plaque in root canals, and plaque on the mucosal surface. The interest and knowledge of the microbiome have dynamically increased with the advancement of technology. Therefore, a reliable, feasible, and practical sampling strategy for the oral microbiome is required for the investigation. This paper introduced the sampling strategy of oral microorganisms, consisting of sample collection, transport, processing, and storage. The materials and devices involved in this study are all commonly used in clinical practice or laboratory. The feasibility and reliability of the sampling methods described in this paper have been verified by multiple studies.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    本文针对有限或小样本序列,提出了一种性能度量来评估具有给定采样策略的控制图的检测性能,并证明了具有动态非随机控制极限和给定采样策略的CUSUM控制图在该度量下可以是最优的。提供了地震的数值模拟和实际数据,以说明对于不同的采样策略,CUSUM图表在变化点检测中将具有不同的监控性能。在六种只抽取一部分样本的抽样策略中,数值比较结果表明,均匀采样策略(均匀分散采样策略)的监测效果最好。
    This article proposes a performance measure to evaluate the detection performance of a control chart with a given sampling strategy for finite or small samples sequence and prove that the CUSUM control chart with dynamic non-random control limit and a given sampling strategy can be optimal under the measure. Numerical simulations and real data for an earthquake are provided to illustrate that for different sampling strategies, the CUSUM chart will have different monitoring performance in change-point detection. Among the six sampling strategies that take only a part of samples, the numerical comparing results illustrate that the uniform sampling strategy (uniformly dispersed sampling strategy) has the best monitoring effect.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    背景:需要比较自动肝脏分割和手动采样MRI策略的性能,以确定互换性。
    目的:为了比较自动肝脏分割和手动采样策略(手动整个肝脏分割和标准化手动感兴趣区域)在量化肝脏体积和MRI质子密度脂肪分数(MRI-PDFF)方面的性能,确定脂肪变性等级,时间负担。
    方法:纳入了在2017年12月至2018年11月期间接受肝活检和MRI检查的50例肥胖患者。采样策略包括自动和手动整个肝脏分割以及4个和9个大的感兴趣区域。组内相关系数(ICC),Bland-Altman,线性回归,接收机工作特性曲线,并进行Pearson相关分析。
    结果:自动全肝分割肝脏体积和手动全肝分割肝脏体积表现出极好的一致性(ICC=0.97),高相关性(R2=0.96),和低偏差(3.7%,95%的协议限制,-4.8%,12.2%)在肝脏体积中。有最好的协议(ICC=0.99),最高相关性(R2=1.00),和最小偏差(0.84%,95%的协议限制,-0.20%,1.89%)在自动全肝分割MRI-PDFF和手动全肝分割MRI-PDFF之间。检测脂肪变性的受试者工作特征曲线的每个配对比较没有差异(P=0.07-1.00)。自动全肝分割的最小时间负担为0.32s(0.32-0.33s)。
    结论:自动测量在定量肝脏体积方面与手动测量具有相似的效果,MRI-PDFF,并检测脂肪变性。在所有采样策略中,自动整个肝脏分割的时间负担最小。手动测量可以由自动测量代替,以提高定量效率。
    BACKGROUND: The performance of automatic liver segmentation and manual sampling MRI strategies needs be compared to determine interchangeability.
    OBJECTIVE: To compare automatic liver segmentation and manual sampling strategies (manual whole liver segmentation and standardized manual region of interest) for performance in quantifying liver volume and MRI-proton density fat fraction (MRI-PDFF), identifying steatosis grade, and time burden.
    METHODS: Fifty patients with obesity who underwent liver biopsy and MRI between December 2017 and November 2018 were included. Sampling strategies included automatic and manual whole liver segmentation and 4 and 9 large regions of interest. Intraclass correlation coefficient (ICC), Bland-Altman, linear regression, receiver operating characteristic curve, and Pearson correlation analyses were performed.
    RESULTS: Automatic whole liver segmentation liver volume and manual whole liver segmentation liver volume showed excellent agreement (ICC=0.97), high correlation (R2=0.96), and low bias (3.7%, 95% limits of agreement, -4.8%, 12.2%) in liver volume. There was the best agreement (ICC=0.99), highest correlation (R2=1.00), and minimum bias (0.84%, 95% limits of agreement, -0.20%, 1.89%) between automated whole liver segmentation MRI-PDFF and manual whole liver segmentation MRI-PDFF. There was no difference of each paired comparison of receiver operating characteristic curves for detecting steatosis (P=0.07-1.00). The minimum time burden for automatic whole liver segmentation was 0.32 s (0.32-0.33 s).
    CONCLUSIONS: Automatic measurement has similar effects to manual measurement in quantifying liver volume, MRI-PDFF, and detecting steatosis. Time burden of automatic whole liver segmentation is minimal among all sampling strategies. Manual measurement can be replaced by automatic measurement to improve quantitative efficiency.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    背景:以黄金角度增量使用非笛卡尔MRI轨迹具有允许使用中间实时重建的回顾性运动校正和基于图像的门控的优点。然而,当采集的数据被心脏分类用于CINE成像时,轨迹被发现在某些心率下聚集在一起,并在k空间中留下大的未采样间隙,导致图像伪影。在这项工作中,我们(1)展示了一种通过在轨迹内周期性插入额外的角旋转来减少聚类的方法,和(2)优化这些额外的角度使用粒子群优化,同时仍然允许重要的中间重建。
    方法:在恒定和可变心率下模拟了三种采集模型:传统金角(Mtrd),随机附加角度(Mrnd),和优化的附加角度(Mopt)。要分析聚类,计算轨迹角度差(STAD)的标准偏差。通过四分位数范围和Kolmogorov-Smirnov检验比较了STAD的结果分布(显著性水平:p=0.05)。用均匀采样重建的参考图像与从Mtrd获得的图像之间的一致性,Mrnd,通过计算结构相似性指数度量(SSIM)及其四分位范围来分析Mopt。然后在3个健康成年人中比较了Mtrd和Mopt的心率变异性水平(高,低和无)。
    结果:来自Mtrd的STAD分布与Mopt和Mrnd的STAD分布显着不同(p<0.05)。STAD(四分位数范围x10-2rad)显示,与恒定心率下的Mtrd(1.9)相比,Mopt(0.5)和Mrnd(0.5)的聚类减少。同样,对于可变的心率,Mopt(0.5)和Mrnd(0.5)的表现优于Mtrd(0.9)。所提出的方法降低了聚类的风险。SSIM(四分位距),相对于真相重建,表明Mopt(0.011)产生了最好的图像质量,其次是Mrnd(0.014),和Mtrd(0.030),这产生了最差的图像质量。体内研究表明,在降低的心脏变异性下,Mopt的表现优于Mtrd,聚类风险降低。在高心率变异性中,两种模型都表现良好。
    结论:该方法减少了k空间中聚类的发生,并在不影响采集时间的情况下提高了图像质量。
    BACKGROUND: Non-Cartesian magnetic resonance imaging trajectories at golden angle increments have the advantage of allowing motion correction and gating using intermediate real-time reconstructions. However, when the acquired data are cardiac binned for cine imaging, trajectories can cluster together at certain heart rates (HR) causing image artifacts. Here, we demonstrate an approach to reduce clustering by inserting additional angular increments within the trajectory, and optimizing them while still allowing for intermediate reconstructions.
    METHODS: Three acquisition models were simulated under constant and variable HR: golden angle (Mtrd), random additional angles (Mrnd), and optimized additional angles (Mopt). The standard deviations of trajectory angular differences (STAD) were compared through their interquartile ranges (IQR) and the Kolmogorov-Smirnov test (significance level: p = 0.05). Agreement between an image reconstructed with uniform sampling and images from Mtrd, Mrnd, and Mopt was analyzed using the structural similarity index measure (SSIM). Mtrd and Mopt were compared in three adults at high, low, and no HR variability.
    RESULTS: STADs from Mtrd were significantly different (p < 0.05) from Mopt and Mrnd. STAD (IQR × 10-2 rad) showed that Mopt (0.5) and Mrnd (0.5) reduced clustering relative to Mtrd (1.9) at constant HR. For variable HR, Mopt (0.5) and Mrnd (0.5) outperformed Mtrd (0.9). The SSIM (IQR) showed that Mopt (0.011) produced the best image quality, followed by Mrnd (0.014), and Mtrd (0.030). Mopt outperformed Mtrd at reduced HR variability in in-vivo studies. At high HR variability, both models performed well.
    CONCLUSIONS: This approach reduces clustering in k-space and improves image quality.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    合成抗氧化剂,包括合成酚类抗氧化剂(SPA),胺抗氧化剂(AAs),和有机亚磷酸酯抗氧化剂(OPA),是防止各种工业和消费品氧化老化的重要添加剂。这些化学品对环境的污染日益受到重视,但与其他新兴污染物如增塑剂和阻燃剂相比,我们对合成抗氧化剂的理解通常是有限的。许多人将大部分时间(通常超过80%)花在室内,这意味着他们经历了广泛而持续的室内污染物暴露。因此,这种观点的重点是合成抗氧化剂作为室内环境污染物的问题。抗氧化剂在商业产品中的广泛应用及其所证明的毒性使其成为新兴关注的重要室内污染物家族。然而,仍然需要弥合重大的知识差距:需要在室内环境中识别新型合成抗氧化剂及其相关转化产品,应采用不同的粉尘采样策略来评估人类暴露于这些污染物的情况,应扩大室内污染研究的地理范围和采样范围,需要研究合成抗氧化剂在不同介质中的分配系数。
    Synthetic antioxidants, including synthetic phenolic antioxidants (SPAs), amine antioxidants (AAs), and organophosphite antioxidants (OPAs), are essential additives for preventing oxidative aging in various industrial and consumer products. Increasing attention has been paid to the environmental contamination caused by these chemicals, but our understanding of synthetic antioxidants is generally limited compared to other emerging contaminants such as plasticizers and flame retardants. Many people spend a significant portion (normally greater than 80%) of their time indoors, meaning that they experience widespread and persistent exposure to indoor contaminants. Thus, this Perspective focuses on the problem of synthetic antioxidants as indoor environmental contaminants. The wide application of antioxidants in commercial products and their demonstrated toxicity make them an important family of indoor contaminants of emerging concern. However, significant knowledge gaps still need to be bridged: novel synthetic antioxidants and their related transformation products need to be identified in indoor environments, different dust sampling strategies should be employed to evaluate human exposure to these contaminants, geographic scope and sampling scope of research on indoor contamination should be broadened, and the partition coefficients of synthetic antioxidants among different media need to be investigated.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    世界上最大的河流是多种多样的,地方性,受威胁的鱼类物种。然而,它们的庞大规模使大规模生物监测具有挑战性。虽然环境DNA(eDNA)元转录编码已成为较小淡水生态系统中的一种既定监测方法,其对大型河流的适用性可能会受到其横截面范围(>1公里宽和几十米深)的挑战。这里,我们从中国长江下游两个横截面的多个垂直层和水平位置采样了鱼类eDNA。仅在垂直层和水平位置的单个组合中检测到超过一半的ASV(扩增子序列变体)。在所有组合中,有7%。我们估计需要在横截面剖面上采样>100升的水,以实现ASV丰富度饱和,这相当于物种水平的60L水。没有出现一致的模式来优先考虑某些深度和水平样本,然而,我们强调同时采样和整合不同层和位置的重要性。我们的研究强调了使用eDNA方法时空间分层抽样和抽样量的重要性。具体来说,我们开发并测试了可扩展和广泛适用的策略,以促进大型河流的监测和保护。
    The world\'s largest rivers are home to diverse, endemic, and threatened fish species. However, their sheer sizes make large-scale biomonitoring challenging. While environmental DNA (eDNA) metabarcoding has become an established monitoring approach in smaller freshwater ecosystems, its suitability for large rivers may be challenged by the sheer extent of their cross sections (>1 km wide and tens of meters deep). Here, we sampled fish eDNA from multiple vertical layers and horizontal locations from two cross sections of the lower reach of the Yangtze River in China. Over half of the ASVs (amplicon sequence variants) were detected in only a single combination of the vertical layers and horizontal locations, with ∼7% across all combinations. We estimated the need to sample >100 L of water across the cross-sectional profiles to achieve ASV richness saturation, which translates to ∼60 L of water at the species level. No consistent pattern emerged for prioritizing certain depth and horizontal samples, yet we underline the importance of sampling and integrating different layers and locations simultaneously. Our study highlights the significance of spatially stratified sampling and sampling volumes when using eDNA approaches. Specifically, we developed and tested a scalable and broadly applicable strategy that advances the monitoring and conservation of large rivers.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    肉桂疫霉是一种破坏性的土壤传播病原体,在全世界的鳄梨上引起疫霉根腐病。关于根采样时间的影响知之甚少,根定量方法(定量实时PCR[qPCR])与诱饵)和树样品汇集策略,关于鳄梨果园树根中病原体的定量。在林波波省两个气候不同的产区(Mooketsi和Letaba)的六个鳄梨果园中进行了调查,南非,在两年的时间里。两种不同的树样本汇集策略,每公顷由四个集合组(每个包含五个集合树的四个组)或单个集合组(集合20棵树)组成,都显示出适用于使用qPCR或根诱饵定量树根中的肉桂。对于两种定量方法,来自两种树木样品池策略的肉桂疫霉根数均显着相关。两种定量方法均适用于根中病原体的定量。尽管qPCR在确定根采样时间点之间肉桂量的显着差异方面优于根诱饵。采样时间的影响取决于所调查的年份。2017年,根数量,仅使用qPCR进行评估,没有揭示特定采样时间的一致趋势,大多数果园的根系数量最高。然而,2018年,五个果园,基于qPCR分析,5月(深秋)的肉桂根数量明显高于3月(初秋),8月(冬末),10月/11月(春末)。2018年,肉桂根DNA数量与根采样日期前两个月在20-24°C和20-29°C的土壤温度小时数显着正相关,并且与根采样前两个月在15-19°C的小时数呈负相关。我们的研究已经确定了肉桂根定量方法和树木样本汇集策略,这将有助于了解病原体的生物学以及何时应制定疾病管理策略。
    Phytophthora cinnamomi is a destructive soilborne pathogen causing Phytophthora root rot on avocados worldwide. Little is known about the effect of root sampling time, root quantification method (quantitative real-time PCR [qPCR] versus baiting), and tree sample pooling strategies on the quantification of the pathogen in roots in avocado orchard trees. This was investigated in six avocado orchards in two climatically different production regions (Mooketsi and Letaba) in the Limpopo Province, South Africa, over a 2-year period. Two different tree sample pooling strategies, consisting of either a four-pooled group (four groups each containing five pooled trees) or a single-pooled group (20 trees pooled) per 1 ha, were both shown to be suitable for quantifying P. cinnamomi in tree roots using qPCR or root baiting. P. cinnamomi root quantities from the two tree sample pooling strategies were significantly correlated for both quantification methods. Both quantification methods were suitable for quantifying the pathogen in roots, although qPCR was superior to root baiting at identifying significant differences in P. cinnamomi quantities among root sampling time points. The effect of sampling time was dependent on the investigated year. In 2017, root quantities, which were only evaluated using qPCR, did not reveal a consistent trend of a specific sampling time yielding the highest root quantities for most of the orchards. However, five of the orchards in 2018, based on the qPCR analyses, contained significantly higher P. cinnamomi root quantities in May (late autumn) than in March (early autumn), August (late winter), and October/November (late spring). In 2018, P. cinnamomi root DNA quantities were significantly positively correlated with the number of soil temperature hours at 20 to 24 and 20 to 29°C 2 months preceding the root sampling dates and negatively correlated with the number of hours at 15 to 19°C 2 months preceding root sampling. Our study has identified P. cinnamomi root quantification methods and tree sample pooling strategies, which will be useful for understanding the biology of the pathogen and when disease management strategies should be in place.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号