Detection and spread of Phytophthora austrocedri within infected Juniperus communis woodland and diversity of co‐associated Phytophthoras as revealed by metabarcoding     

Carolyn E. Riddell  Heather F. Dun  Matt Elliot  April C. Armstrong  Mhairi Clark  Jack Forster  Pete E. Hedley  Sarah Green 《Forest Pathology》2020,50(3)

Phytophthora austrocedri is a recently invasive soilborne pathogen which is causing widespread mortality of Juniperus communis in northern Britain. The pathways by which a single genotype of P. austrocedri has spread to infect such a geographically dispersed range of woodland sites within a relatively short timeframe are unknown. This study examined the detectability of P. austrocedri in soil and water within infected J. communis woodland using qPCR to gain a better understanding of the pathogen's key mechanisms of spread. A Phytophthora metabarcoding method was also applied to investigate the wider diversity of Phytophthora species present in water at one of the sites. qPCR analyses of P. austrocedri in soil samples at a J. communis woodland exhibiting low‐to‐moderate levels of disease suggested a slow natural spread of the pathogen in soil, requiring high moisture conditions. However, the ubiquity of P. austrocedri DNA in soil samples collected across a heavily infected J. communis site suggests that once established at a site the pathogen can be spread readily in soil locally, most likely vectored by animal movements and/or human activities. The hypothesis that P. austrocedri is aerially transmitted in rainwater was not adequately proven, and an alternative hypothesis for the widespread distribution of the pathogen on J. communis in northern Britain is presented. Metabarcoding identified DNA from a diverse range of Phytophthora species in river and rainwater samples although the main target pathogen, P. austrocedri, was not amplified which disagreed with some of the qPCR findings. Possible reasons for this are discussed.  相似文献   

小菜蛾磷酸丝氨酸磷酸酶基因的克隆与原核异源表达     

李平  刘吉元  张雅林  王敦 《西北农林科技大学学报(自然科学版)》2010,38(2):179-183

【目的】克隆小菜蛾磷酸丝氨酸磷酸酶基因(Plutella xylostellaphosphoserine phosphatase,PxPP),并进行原核异源表达,为小菜蛾抗性机理研究奠定基础。【方法】提取小菜蛾的总RNA,反转录获得总cDNA,采用RT-PCR方法扩增目的基因,将其克隆进T载体并测序,然后将目的基因克隆到大肠杆菌表达载体pET-28a(+)中表达。【结果】目的基因序列分析结果表明,PxPP阅读框全长693 bp,编码230个氨基酸,预测编码蛋白分子质量和等电点分别为25.6 ku和5.82,表达的融合蛋白分子质量为26.9 ku。【结论】成功克隆和表达了小菜蛾磷酸丝氨酸磷酸酶基因。  相似文献   

曙光农场农业现代化评价及发展对策研究          下载免费PDF全文

陈志英王兆祥  马天祥敦成园李婷  沙春宇 《农学学报》2014,4(5):96-100

实现农业现代化是中国农业发展的长期奋斗目标和战略决策。“十二五”规划纲要明确指出在工业化、城镇化深入发展中同步推进农业现代化。笔者从农业投入、产出、地区发展、可持续发展、产业结构及产业化5个方面设立指标,对曙光农场的农业现代化水平进行评价,根据评价结果分析曙光农场发展农业现代化的优势和不足,并结合曙光农场实际提出发展建议,希望为曙光农场农业现代化建设提供借鉴。  相似文献   

花生体内几种酶的活性与抗锈病性的关系   总被引：14，自引：1，他引：14  

李盾  王振中 《华南农业大学学报》1991,12(3):1-6

在锈菌侵染前和侵染后的若干阶段测定了具有不同程度抗性的5个花生品种中的苯丙氨酸解氢酶(PAL),过氧化物酶(PO),多酚氧化酶(PPO)活性,并分析其与抗性的关系。结果表明,PAL是一种诱导酶,在测定的大多数时间内,呈现酶活性越大,抗性越强的趋势;在侵染后的12,24和48h,大多数品种病叶的PO活性高于健叶,基本上是品种愈感病酶活性变化愈大;在健康叶片中,PPO的活性变化与抗锈病性显著相关,但在受锈菌侵染的叶片组织中,PPO的活性变化似与抗性无明显相关。  相似文献   

New technology of sow breed-feeding in different embryo     

Deng Dun  Wang Bin 《饲料工业》2008,29(3)

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Unexpected death in a horse with arytenoid chondritis and perilaryngeal lesions     

MP FRANCE  TLW ROTHWELL  NJ KANNEGIETER† 《Australian veterinary journal》1995,72(9):351-352

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Cattle tick (Boophilus microplus) in Victoria on horses from Queensland     

TF JUBB  NJ CAMPBELL 《Australian veterinary journal》2002,80(1):92-93

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大连地区针叶树根部土壤中的4种滑刃线虫     

丛东日  闫超杰  段玉玺 《植物检疫》2007,21(1):12-14

本文对大连地区针叶树木根部土壤寄生线虫进行了采样调查，描述了分离鉴定到的双尾滑刃线虫，内卷滑刃线虫，林伯滑刃线虫和墙草滑刃线虫等滑刃属的4个种的形态特征，并进行了数据测量。  相似文献   

Bone marrow study of cows in the dynamics of the leukemic process]     

E A Dun  L G Burba 《Veterinariia》1979,(2):27-29

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6-BA、GA3打破秋莴苣高温休眠及对生长发育的影响     

成玉富  姜敦云  赵有为 《扬州大学学报(农业与生命科学版)》2000,21(1):41-44

试验选用冬莴苣、白尖叶和雁翎3个莴苣品种,在不同温度下进行发芽试验,并用6-BA、GA3处理莴苣种子,研究莴苣的发芽规律和6-BA、GA3打破高温休眠的效果.结果表明莴苣种子存在明显的高温休眠现象,当温度超过25℃时开始进入休眠,超过32℃时完全休眠.6-BA、GA3打破高温休眠、促进萌发的作用显著,6-BA+GA3混合处理效果更好.GA3处理促进莴苣茎叶伸长,6-BA促进莴笋增粗,6-BA+GA3混合处理既促进莴苣茎叶伸长,又促进莴笋增粗,莴笋粗长,增产效果显著.  相似文献