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1.
Simple diagnosis by ethanol immersion (SDEI) to detect Glomerella cingulata was used to detect three other fungi that also cause latent infection of strawberry plants. Signs on strawberry leaves with asymptomatic latent infection by Colletotrichum acutatum became visible using SDEI. Salmon-pink conidial masses were produced in the acervuli on the treated leaves 5 days after incubation at 28°C. In the case of Dendrophoma obscurans, pycnidia with amber conidial masses formed 5 days after incubation at 28°C. The pycnidia were observed mainly on the ribs, and conidial masses exuded from the ostiole. These macroscopic conidial masses were similar to those of G. cingulata and C. acutatum. When water was dripped onto a lesion caused by D. obscurans, the pycnidia exuded white filamentous conidial masses, making the distinction of D. obscurans from G. cingulata or C. acutatum. On petioles with latent infection by Fusarium oxysporum f. sp. fragariae, white aerial hyphae grew out from the vascular tissues on the cut surface 3 days after incubation at 28°C and were easily observed by eye or with a loupe. Thus, SDEI was also useful for diagnosing latent infection of strawberry plants by C. acutatum, D. obscurans, and F. oxysporum f. sp. fragariae.  相似文献   
2.
Various tissues of menhaden fish were analyzed for macro and micro minerals. Tissues selected were gill, heart, intestine, kidney, liver, muscle, spleen, and stomach. Phosphorus, calcium, magnesium, sodium, manganese, and zinc were found to be most concentrated in the gill. Potassium, iron, and boron were least concentrated in the gill. Liver contained the highest concentration of copper, selenium and boron. The stomach was the highest in potassium and lowest in phosphorus. Sodium and selenium concentrations were lowest in the muscle. Mercury concentrations were approximately 2 mg/g dry matter in all tissues  相似文献   
3.
以果蔗(Badila)茎尖脱毒组培苗为材料,利用间歇浸没式生物反应器(Temporary immersion bioreactors TIBs)进行组培快繁的技术体系的研究。结果表明:(1)使用TIBs系统进行甘蔗组织培养一代增殖较传统方法高出10倍以上;(2)TIBs系统以第4代继代材料为宜;(3)接种密度在10~15株/L培养基最有利于甘蔗组培苗的增殖和生长;(4)TIBs系统中6-BA浓度为0.5~1.0mg/L时适合于增殖培养,NAA浓度为4mg/L时有利于根的诱导;(5)浸没间歇频率在1min/3h时增殖和生长表现较为优异,1min/6h时有利于根的诱导和根的生长。  相似文献   
4.
Streptococcus iniae and Gyrodactylus niloticus are two common pathogens of cultured Nile tilapia, Oreochromis niloticus. We studied concurrent infection of tilapia by G. niloticus and S. iniae and evaluated whether parasitism in tilapia with Gyrodactylus increased susceptibility and mortality following immersion infection with S. iniae. Results showed that death mainly occurred in fish with G. niloticus and challenged with S. iniae (G-S group). The accumulative mortality (42.2%) was significantly higher in the G-S group than in fish not infected by the parasite (6.7%), but exposed to S. iniae. Bacteriological examination revealed S. iniae from > or =92% of dead or moribund fish challenged with S. iniae. Gyrodactylus not only damaged fish epithelium and provided entry for invasive bacteria but also was found to harbour viable cells of S. iniae for 24 and 72 h. Streptococcus iniae was isolated from 60% and 40% of G. niloticus collected from fish infected by intraperitoneal injection or immersion, respectively, at 24 h post-challenge. The present study confirms that parasitism of tilapia by G. niloticus increased host mortality following exposure to the bacterial pathogen S. iniae.  相似文献   
5.
应用间接ELISA方法,研究经嗜水气单胞菌(Aeromonas hydrophila)疫苗浸泡免疫后鳜(Siniperca chuatsi)皮肤黏液中抗体消长规律,以揭示鳜局部黏膜免疫在免疫保护中的作用及浸泡免疫的保护效果。结果表明,鳜皮肤黏液中抗体滴度在免疫后第7天达到峰值211,抗体从开始形成到消失持续21 d;添加佐剂(IMS1312、葡聚糖、莨菪碱、食盐)可以提高鳜皮肤黏液及血清中抗体滴度和相对免疫保护率,其中添加IMS1312组免疫保护率最高,达77.8%,免疫保护与抗体滴度成正相关(R2=0.79,P<0.05);以溶菌酶为代表的非特异性免疫在免疫后1周内即抗体未形成时,对鱼体起主要保护作用。此外,通过比较鳜血清与皮肤黏液中的抗体消长规律,发现血清中抗体滴度峰值出现时间较迟(第14天),抗体持续时间较长(42 d),初步推断鳜皮肤黏膜中可能存在相对独立于全身免疫系统的局部黏膜免疫系统。  相似文献   
6.
In this study, Intraperitoneal (IP) and bath immersion (BI) vaccine trials were conducted in fish with a mean weight of 6.3 g. Rainbow trout vaccinated with lipopolysaccharide (LPS) was 50 mg/L protein concentration and challenged by IP injection with 9.8 × 106 cell/ml of Yersinia ruckeri at 45 days post-immunization had a relative percent survival (RPS). To obtain an effective bath immersion vaccine against yersiniosis, LPS preparation was obtained from the Y. ruckeri and with the LPS antigen. After 28 and 60 days vaccinated fish with first and second immunizations by LPS were challenged via intraperitoneal injection with 9.8 × 106 cell/ml of Y. ruckeri for evaluating the mortality rates and calculating the relative percentage of survival (RPS). RPS value of experimental groups, which was significantly (P < 0.05) larger than that of the control group.  相似文献   
7.
ABSTRACT:   The ability of salmon growth hormone (sGH) to accelerate the somatic growth of juvenile abalone Haliotis discus hannai by immersion was examined. After immersion for one hour into a sGH-rich solution at a concentration of 30 mg/L, the sGH immunoreactivity in the body fluid of abalone was maximal after one day, and levels were still detectable at two days. No immunoreactivity was observed in the control group. Following immersion for one hour at one or two-week intervals for 120 weeks into the sGH-rich solution at 30 mg/L, the sGH-immersed abalone exhibited a significant increase in shell length and body weight. On the other hand, abalone immersed into a salmon prolactin (sPRL)-rich solution at 30 mg/L for one hour showed a lower increase in both shell length and body weight than the sGH-immersed abalone. No increases in shell length and body weight were observed in either the bovine serum albumin-immersed abalone or untreated controls. These results provide evidence that sGH can be transported from ambient water into the circulatory system of abalone, and can subsequently improve the somatic growth of juveniles.  相似文献   
8.
由于黄泛区平原水库坝基一般为软弱透水地基,坝基经过防渗处理后,坝基渗透稳定,渗漏量得到有效控制,但坝基不可避免的还有一定数量的渗漏量,下游坝址外尚保留一定的剩余水头,渗水如果不及时排走,会导致区域地下水位升高,造成库外农田浸没。笔者以山东聊城发电厂新厂引黄调蓄水库为依托,阐述平原水库如何用排渗沟和减压井联合排渗减压技术防止库外浸没和土地盐碱化。减压井和排渗沟联合排渗减压是降低地下水位、防止库外浸没的有效措施。  相似文献   
9.
研究了冷水、热水、苯 醇、苯 乙醚、10 g.kg-1盐酸(HCl)和10 g.kg-1氢氧化钠溶液(NaOH)浸提处理后毛竹Phyllostachys pubescens的霉变性能。结果表明:①经10 g.kg-1HCl浸提的竹片防木霉Trichoderma viride,橘青霉Penicillium citrinum和黑曲霉Aspergillus niger效果最佳,接种1个月后试样平均被害值均为0。②经10 g.kg-1NaOH浸提的竹片对木霉、橘青霉有较好的防霉效果。经10 g.kg-1NaOH浸提的竹片如不经过水洗,接种1个月后试样平均被害值均为0;而经过水洗后防霉效果有不同程度下降,对木霉和橘青霉而言,处理后试样平均被害值分别为1.58和0.35。经10 g.kg-1NaOH浸提的竹片对于黑曲霉的防治效果不佳,10 g.kg-1NaOH浸提后的竹片水洗前后对黑曲霉的试样平均被害值分别为1.82和2.79。③经冷水、热水、苯 醇、苯 乙醚浸提竹片的防霉效果均不佳,7 d以后试样平均被害值均已达到3.00以上,主要原因在于不同溶液浸提出的竹材内含物成分和数量不同。图3表2参12  相似文献   
10.
嗜水气单胞菌灭活苗的研制   总被引:6,自引:0,他引:6  
选取具有HEC毒素的致病性菌株AH3,按照最佳培养条件制成AH3灭活全菌苗。免疫接种小鼠和鲫鱼,小鼠获得完全免疫,鲫鱼注射免疫组保护率为75%,浸泡免疫组保护率为33%,对照组保护率为0%。  相似文献   
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