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81.
【目的】明确近年来引起甘肃大棚甜瓜叶斑病的病原,为该病害的有效防治提供参考依据。【方法】本试验分别采用组织分离法、单孢分离法和生长速率法,对甜瓜叶斑病病原菌及其物学特性和室内药剂筛选进行了研究。【结果】将引起甜瓜叶斑病病原菌病原菌鉴定为多隔链格孢(Alternaira peponicola( Rabenhorst ) simmous)和瓜链格孢(Alternaria cucumerina(Ell.et Ev.)Elliott.);这两种链格孢生长的最适温度为30℃、光照、适宜培养基分别为完全光照、甜瓜煎汁培养基和完全黑暗、PDA;室内药剂筛选发现不同药剂对不同病原菌抑菌率不同,其中10%苯醚甲环唑、40%氟硅唑、50%福美双、70%代森锰锌对多隔链格孢菌抑菌率均在84%以上,分别为96.66%、94.46%、90.82%、84.37%,其EC50分别为17.89μg/mL、3.41μg/mL、44.27μg/mL、42.34μg/mL;50%醚菌酯、43%戊唑醇、40%腈菌唑对瓜链格孢抑菌作用较好,抑菌率均在85%以上,分别为98.20%、90.82%、85.43%,其EC50分别为3.45μg/mL、21.35μg/mL、5.21μg/mL。【结论】研究结果为甜瓜叶斑病的有效防治提供了依据。 相似文献
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为了探究鼠李糖凝集素(Rhamnose-binding lectin, RBL)在硬骨鱼非特异性细胞防御病原菌感染中的作用,本研究以尼罗罗非鱼为研究模型,首先通过分离头肾单核/巨噬细胞进行体外菌应激实验,发现在罗非鱼两种重要的致病菌-无乳链球菌(Streptococcus agalactiae)和嗜水气单胞菌(Aeromonas hydrophila)应激后,尼罗罗非鱼L-鼠李糖凝集素1(OnRBL-1)的表达量显著上调。然后,通过荧光定量PCR(qRT-PCR)检测发现OnRBL-1重组蛋白能够调节病原菌诱导细胞炎症因子的表达,包括显著抑制菌诱导的IL-6、IL-8和TNF-α的表达,和促进IL-10和TGF-β的表达。此外,通过流式细胞术检测证实OnRBL-1具有促进单核/巨噬细胞的吞噬作用,同时增强呼吸爆发水平和上调活性氧的释放。以上研究结果表明,OnRBL-1在罗非鱼单核/巨噬细胞非特异性细胞防御中发挥重要的调节作用。本研究为探讨RBL-1在硬骨鱼宿主防御病原菌感染中的功能提供了参考,并有助于完善和丰富硬骨鱼类RBL的功能和在抗菌免疫应答中的基础理论体系,具有重要的科学意义。 相似文献
84.
采用通用引物PCR配合SSCP和RFLP技术检测鱼病病原菌 总被引:8,自引:0,他引:8
采用通用引物PCR(UPPCR)、PCR-RFLP、PCR-SSCP技术,研究快速鉴别鱼病病原菌的分子生物学诊断技术。结果发现,采用细菌16S rRNA基因保守区特异性引物,以嗜水气单胞菌、鲁克氏耶尔森菌、鳗弧菌、柱状曲挠杆菌、乙型链球菌、荧光假单胞菌等部分常见鱼病病原菌为对象,可以建立一种UPPCR技术。该技术能在保证实验条件不变的基础上,检出上述所有细菌,并还可检出大肠杆菌和双歧杆菌等非鱼病病原菌。并且认为,该法与SSCP配合即采用UPPCR-SSCP技术能较好地鉴别被检菌而用于鱼病病原菌的快速诊断。 相似文献
85.
对青岛近海度假区、港口区、养殖区、工业区4类排污口邻近海域异养细菌的组成与分布进行了调查研究,采用海洋异养细菌平板涂布培养法分离细菌,基于16S rDNA的扩增性DNA限制性酶切片段分析(ARDRA)进行聚类筛选并测序鉴定。结果显示,青岛排污口邻近海域可异养培养的菌株分布于变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes)4个细菌类群,变形菌门细菌数量占总测序数量的68%,其中γ-变形菌纲的数量在变形菌门中占88%;不同海域中细菌组成与分布有所不同,放线菌门和拟杆菌门的细菌种类较少且各海域分布有所不同,但γ-变形菌纲的弧菌属细菌(Vibrio sp.)在4类海域中均被发现,占总检测量的18.54%,其中溶藻胶弧菌(Vibrio alginolyticus)占弧菌总量的25%。不同海域也检测到V.parahaemolyticus、V.harveyi、V.campbellii、V.parahaemolyticus等水产养殖业的潜在致病菌。根据16S rDNA系统进化关系和细菌门类聚类分析得到的结论推断,工业区与养殖区海域的细菌组成和分布相似度较高,推断各海域的细菌组成与排污口类型有一定相关性。 相似文献
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John Castell Tammy Blair Steven Neil Kenneth Howes Sarah Mercer John Reid Wilfred Young-Lai Brandi Gullison Philippe Dhert Patrick Sorgeloos 《Aquaculture International》2003,11(1-2):109-117
A feeding study was conducted in the winter 2001 to determine the effects of feeding rotifers (Brachionus plicatilis) enriched with various levels of essential fatty acids on the growth and survival of haddock larvae (Melanogrammus aeglefinus). Rotifer enrichment treatments were: 1) mixed algae, 2) high DHA (docosahexaenoic acid, 22:6n-3), 3) high DHA and EPA (eicosapentaenoic acid, 20:5n-3), and 4) DHA, EPA, and AA (arachidonic acid, 20:4n-6). Larvae were fed rotifers enriched with the different treatments from days 1 to 16 post-hatch. From day 17 until 25 all treatment groups were fed rotifers reared on mixed algae and then weaned onto the International Council for Exploration of the SEA (ICES) Standard Reference Weaning diet (http://allserv.rug.ac.t/aquaculture/rend/rend.htm) over a five day period. The experiment was terminated on day 41 post-hatch. The enrichment treatments affected the fatty acid composition of the rotifers and correlated with the accumulation of these fatty acids in the haddock larvae. However, no significant differences in larval growth or survival to 40 days post hatch were detected, suggesting that all treatments provided the minimal essential fatty acid requirements for haddock. 相似文献
88.
《Journal Of Aquatic Food Product Technology》2013,22(3):95-105
ABSTRACT Quantitative levels of six known pathogens (Listeria monocytogenes, Clostridium botulinum, Salmonella species, Vibrio cholerae, Yersinia enterocolitica, and Y. pseudotuberculosis) and aerobic plate counts were measured at five aquaculture facilities. The farmed rainbow trout (Oncorhynchus mykiss) and trout fillets were sampled at two different growing seasons to monitor for microbial hazards. Listeria spp. was identified in both whole trout and trout fillets from all five facilities sampled from both growing seasons. Presumptive Clostridium botulinum spores were also identified from all five facilities for both seasons. The growing season did not affect pathogen levels and there was no evidence that any one aquacultural system was superior to the others. Salmonella spp., Vibrio cholerae, and Yersinia spp. were not isolated from any of the trout samples analyzed. 相似文献
89.
Atle Foss Albert K. Imsland Erik Vikingstad Sigurd O. Stefansson Birgitta Norberg Skjalg Pedersen Trond Sandvik Bjrn Roth 《Aquaculture (Amsterdam, Netherlands)》2009,290(3-4):304-310
A group of juvenile Atlantic halibut (mean, SD, 199.5 g, 44.7) was split into two experimental groups: one group was fed in excess twice a day and later five days a week (i.e. Control group), and the other group was starved for 5 weeks and then subsequently re-fed for 10 weeks (i.e. 5/10 starvation/re-fed group). This treatment was repeated for three years until the fish were harvested (mean final weight, 4.4 kg). A size +specific compensatory response was seen; partial compensation was observed in halibut weighing less than 500 g whereas full recovery growth was seen in halibut over 2 kg. Food consumption and feed conversion efficiency was measured during two full 5/10 starvation/re-fed cycles. The Control group consumed 86% more food in the measurement period, whereas the FCE 40% higher in the 5/10 starvation/re-fed group (FCE = 0.95) compared to the Control group (FCE = 0.68). In males lower gonadosomatic index (2.2 vs. 3.0) and plasma 11-ketotestosterone (0.22 vs. 1.26 ng ml− 1) levels in the 5/10 starvation/re-fed group were observed during late winter and spring of 2006 (age 3 years) indicating higher age at 1st maturity. Starvation had a significant effect for improving the quality as starved fish had higher muscle pH (6.4 vs. 6.2), less gaping (0.1 vs. 0.3) and harder texture (61.4 vs. 57.6 N). Overall, the rearing on a repeated 5/10 starvation/re-fed regime for 3 years led to full growth compensation, higher feed conversion efficiency, lower male maturation and improved flesh quality. 相似文献
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