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81.
以分离自传统发酵乳的55株德氏乳杆菌保加利亚亚种为研究对象,通过分析其发酵时间、后酸化、黏度、脱水收缩性和游离氨基酸态氮等发酵特性,最终得到3株可作为酸乳发酵剂用的德氏乳杆菌保加利亚亚种菌株,分别为IMAU80319、IMAU20422和IMAU20404.  相似文献   
82.
菜豆种子普通细菌性疫病菌检测   总被引:2,自引:0,他引:2  
 由Xanthomonas axonopodis pv. phaseoli和Xanthomonas fuscans subsp. fuscans引起的菜豆普通细菌性疫病是严重影响菜豆生产的限制因子之一,可造成严重的产量和品种损失。染菌种子是病原菌传播的主要途径。本研究对5个菜豆主要产区的60份菜豆种子样品进行普通细菌性疫病菌检测。在MT选择性培养基上有36份种子样品浸提液检测到目标病原菌, 种子样品带菌量为2.49×102~5.20×107 CFU/粒。选择36个分离物接种感病品种“英国红”植株,所有分离物均引起接种植株发病。特异PCR检测结果表明,有20个分离物为X. fuscans subsp. fuscans,16个分离物为X. axonopodis pv. phaseoli。试验结果表明,我国一些菜豆主产区商业种植和研究用种子多数污染普通细菌性疫病菌,建议建立无菌种子生产区和加强种子管理,以有效控制病害发生。  相似文献   
83.
Francisella noatunensis subsp. orientalis (Fno) (syn. F. asiatica) is an emergent Gram‐negative facultative intracellular bacterium. Although it is considered one of the most pathogenic bacteria in fish, there are no commercially available treatments or vaccines. The objective of this project was to determine the most efficacious concentration of florfenicol (FFC) [10, 15 or 20 mg FFC kg?1 body weight (bw) per days for 10 days] administered in feed to control experimentally induced infections of Fno in Nile tilapia, Oreochromis niloticus (L.), reared in a recirculating aquaculture system. The cumulative mortality of fish that received 0, 10, 15 or 20 mg FFC kg?1 bw per day was 60, 37, 14 and 16%, respectively. Francisella noatunensis subsp. orientalis genome equivalents were detected in water from all challenged groups with slight reduction in the concentration in the florfenicol‐treated groups 4 days after treatment. The mean LOG of CFU Fno mg?1 spleen was 3–5 and was present in all challenged groups at necropsy 11 days after treatment (21 days after challenge). Results show that florfenicol administered at doses of 15 and 20 mg FFC kg?1 bw per days for 10 days significantly reduced mortality associated with francisellosis in Nile tilapia.  相似文献   
84.
张君毅 《江西农业学报》2011,23(12):31-33,37
为开发兰科植物叶绿体微卫星(cpSSR)引物,对台湾蝴蝶兰叶绿体全序列进行cpSSR统计分析。结果表明台湾蝴蝶兰SSR以单碱基重复为主,占总数的78.3%。在单碱基重复中又以A和T重复为主,占95.8%。重复方式以完全重复为主,占总数的70%。开发出3对cpSSR引物。  相似文献   
85.
F. Kobayashi 《Crop Protection》2011,30(11):1514-1518
To establish a method for disinfecting hydroponic culture solutions using ozone microbubbles (OMB), we examined the disinfectant activity of OMB against Fusarium oxysporum f. sp. melonis and Pectobacterium carotovorum subsp. carotovorum in infected plant roots. OMB had a higher solubility and remained in the water for a longer period than ozone millibubbles, resulting in extremely high disinfecting activity against both phytopathogens. Furthermore, disinfectant activity and durability of OMB-treated water against both phytopathogens increased with an increase in the initial concentration of dissolved ozone. Therefore, these results suggest that OMB may be suitable for use as a new disinfectant against phytopathogens in hydroponic culture solutions.  相似文献   
86.
甘蔗赤条病菌巢式PCR检测   总被引:2,自引:2,他引:0  
甘蔗赤条病是由燕麦食酸菌燕麦亚种(Acidovorax avenae subsp.avenae,Aaa)引起的一种世界性甘蔗细菌病害。为建立Aaa快速、灵敏的检测技术,根据该病菌16S~23S核糖体基因及其转录间隔区ITS分别设计2对特异性引物,建立Aaa巢式PCR检测方法。结果表明,建立的巢式PCR方法对Aaa标准菌株、水稻食酸菌A.oryzae具有特异性,可扩增出454 bp目的条带,对近缘种德氏食酸菌A.delafieldii及其它科属的红色雷夫松氏菌Leifsonia rubra和甘蔗宿根矮化病菌L.xyli subsp.xyli未扩增出任何条带。以感染Aaa的甘蔗叶片总DNA、含ITS靶标片段的质粒DNA标准品及Aaa标准菌液为模板,巢式PCR灵敏度最低检测限分别为10 fg/μL、10拷贝/μL和36 CFU/mL,是常规PCR灵敏度的1 000倍。应用巢式PCR和常规PCR对14份有赤条病症状的田间甘蔗叶片样品进行平行检测,阳性检出率分别为100.0%和28.6%,表明巢式PCR比常规PCR检测方法具有更高的灵敏度。本研究建立的巢式PCR方法适合于田间甘蔗赤条病害的分子检测与鉴定。  相似文献   
87.
为了寻找分支杆菌耐药菌的新药靶点,根据GenBank的相应序列,利用特异性引物经PCR扩增获得了鸟分支杆菌鸟亚种的泛酸激酶基因,将该基因亚克隆入pET32a(+)载体中,经IPTG诱导和SDS-PAGE检测。结果表明,该基因成功获得表达,并以可溶性蛋白形式存在,利用His纯化试剂盒获得了纯化产物,为下一步进行酶活性测定、酶活性位点的突变及合成酶类似物等研究奠定了基础。  相似文献   
88.
韩赟  郭晗  逯忠新 《现代农业科技》2010,(2):325-325,327
为了解丝状支原体山羊亚种在青海地区的流行状况,利用丝状支原体山羊亚种抗体检测正向间接血凝试剂盒对2007~2009年采自青海各地区的1 200份山羊血清进行检测。结果显示:不同地区山羊血清的阳性率从5.0%~21.0%不等,平均阳性率为16.1%。从季节上看,冬春季节发病率要高于夏秋季节。青海地区的丝状支原体山羊亚种的感染率偏高,应该加强对由丝状支原体山羊亚种的防控。  相似文献   
89.
The management of burnt wood after a fire may affect seed predation by vertebrates due to the change produced in habitat structure. We analyze the effect of burnt wood management on post-dispersal seed predation in the Holm oak. Three plots were established in a burnt forest, with three treatments per plot: (1) non-intervention (NI, all trees left standing), (2) “partial cut plus lopping” (PCL, felling 90% of trees, cutting their main branches, leaving all the biomass in situ), and (3) “salvage logging” (SL, felling the logs for their removal and masticating the woody debris). Acorns were buried to mimic dispersal by jays or rodents two and three years after fire, with two trials per year (7200 monitored acorns), and the predation rate was evaluated until the time of seedling emergence. The spatial patterns of acorn predation were assessed by computing a transformed-Ripley's K function and Moran's I correlograms. There was a large spatial and temporal variability in acorn predation, with differences among trials, plots, and replicates within treatments and plots. Overall, PCL showed the lowest predation values (83.0% versus 87.4 in NI and 88.0 in SL). Predator species (mice versus wild boar) also differed among treatments, wild boar having a negligible effect in PCL, presumably due to the physical barrier of felled logs and branches. The results support that: (1) salvage logging offers no advantage against predators and (2) that post-fire burnt wood management alters the guild of acorn predators and may reshape the pattern of seedling establishment.  相似文献   
90.
Verticillium wilt of olive is best managed by resistant cultivars, but those currently available show incomplete resistance to the defoliating (D) Verticillium dahliae pathotype. Moreover, these cultivars do not satisfy consumers' demand for high yields and oil quality. Highly resistant rootstocks would be of paramount importance for production of agronomically adapted and commercially desirable olive cultivars in D V. dahliae‐infested soils. In this work, resistance to D V. dahliae in wild olive clones Ac‐13, Ac‐18, OutVert and StopVert was assessed by quantifying the fungal DNA along the stem using a highly sensitive real‐time quantitative polymerase chain reaction (qPCR) protocol and a stem colonization index (SCI) based on isolation of V. dahliae following artificial inoculations under conditions highly conducive for verticillium wilt. Ac‐13, Ac‐18, OutVert and StopVert showed a symptomless reaction to D V. dahliae. The mean amount of D V. dahliaeDNA quantified in stems of the four clones ranged from 3.64 to 28.89 pg/100 ng olive DNA, which was 249 to 1537 times lower than that in susceptible Picual olive. The reduction in the quantitative stem colonization of wild olive clones by D V. dahliae was also indicated by a sharp decrease in the SCI. Overall, there was a pattern of decreasing SCI in acropetal progression along the plant axis, as well as correlation between positive reisolation and quantification of pathogen DNA. The results of this research show that wild olive clones Ac‐13, Ac‐18, OutVert and StopVert have a valuable potential as rootstocks for the management of verticillium wilt in olive.  相似文献   
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