中国姜瘟病的研究进展

姜瘟病是中国生姜生产上发生较为普遍的病害,是由青枯劳尔氏菌(Ralstoniasolanacearum)引起的。此病原菌寄主范围广,可侵染44个科300多种植物。菌体短杆状,在TZC选择性培养基上培养出现白边较宽和白边较窄的两种菌落。菌系划分为5个生理小种和5个生化型,中国的姜瘟菌主要属生理小种1号,生物型属II、III、IV。此病害是一种较难防治的土传病害,在高温、高湿、雨水多、氮肥过量的情况下发生较为严重。中国植病工作者对此病害作了大量的研究工作,对中国姜瘟病的病原菌、发病规律、及防治等研究进展作一综述。     

工厂化生产杏鲍菇细菌性病害的防治

工厂化生产杏鲍菇细菌性病害,是由假单孢杆菌引发的重要病害,在特定的控温、控湿、控光、控CO2条件下,每年重复利用出菇房18次以上的出菇房很容易发生、并迅速传播,给杏鲍菇工厂化生产企业带来不同程度的损失;研究、制定的10条预防措施,可以有效控制病害的发生、蔓延。     

海南甜瓜细菌性果斑病田间药效试验

进行了5种药剂防治甜瓜细菌性果斑病田间药效试验。试验结果表明,第二次施药后7 d,5种药剂处理中以20%二氯异氰尿酸钠可湿性粉剂750倍液的防效最好,为65.47%,其次为53.8%可杀得(氢氧化铜)2000干悬浮剂800倍液,防效为56.45%;25%叶枯唑可湿性粉剂750倍液、72%农用链霉素可溶性粉剂3 000倍液和12%松脂酸铜乳油800倍液3个处理的防效分别为51.60%,50.86%和50.20%。上述药剂在生产上可轮换使用,5 d 1次,连续2~3次。     

多种接种途径对翘嘴鳜细菌性烂鳃和败血症的免疫预防效果

多种接种途径对翘嘴鳜细菌性烂鳃和败血症的免疫预防效果陈昌福，周文豪（华中农业大学水产学院，武汉４３００７０）陈昌福等（１９９５）先后用从患细菌性烂鳃病的翘嘴鳜（ＳｉｎｉｐｅｒｃａｃｈｕａｔｓｉＢ．）上分离的柱状嗜纤维菌（Ｃｙｔｏｐｈａｇａｃｏｌｕｍｎ...     

温室池水环境与罗非鱼运动性气单胞菌败血症爆发的关系

为阐明温室池水环境对罗非鱼运动性气单胞菌败血症发生的影响,对5年监测所得的发病池的95个水样和无病池的78个水样的水环境因子值进行了统计分析。结果表明,虽然发病池和无病池的水温平均值和pH平均值差异均不显著(p＞0.05),但在18～27 ℃范围内,发病池出现的百分率随水温升高而增加;发病池的溶解氧、总氨氮、分子氨氮、亚硝酸盐氮、有机物化学耗氧量的平均值分别为2.85±1.45、2.48±0.99、0.067±0.048、0.361±0.233、39.56±20.31 mg/L;无病池的溶解氧、总氨氮、分子氨氮、亚硝酸盐氮、有机物化学耗氧量的平均值分别为3.41±1.39、0.94±0.76、0.025±0.025、0.105±0.066、20.62±9.73 mg/L。发病池的溶解氧平均值显著低于无病池(p＜0.05),发病池的总氨氮、分子氨氮、亚硝酸盐氮、有机物化学耗氧量的平均值分别极显著高于无病池(p＜0.01)。根据发病池和无病池出现的百分率随各环境因子变化的趋势可以得出结论：高水温、低溶解氧、高氨氮、高分子氨氮、高亚硝酸盐氮和高有机物化学耗氧量的池水更容易诱发凡隆气单胞菌温和生物型引起的罗非鱼运动性气单胞菌败血症。     

抗青枯病花生种质资源的鉴定与筛选

为筛选适宜河南省信阳市种植的抗青枯病花生品种,对27份花生品种青枯病田间病圃进行鉴定,计算其发病率和病情指数,从而进行抗病性鉴定和筛选.结果表明,27个供试品种中,中高抗品种共10个占总数的37％,3个品种类型各筛选出2个抗病品种.6个抗病品种发病规律表明,7天和14天病情指数增长较快,21天后基本无变化.高油型花生'...     

DGGE fingerprinting of culturable soil bacterial communities complements culture-independent analyses

Culture-dependent DGGE (CD DGGE) fingerprinting of the 16S rRNA gene was used to characterize mixed bacterial communities recovered on agar plates. Using R2A Agar as a growth medium, CD DGGE analysis resulted in clear banding patterns of sufficient complexity (16-32 major bands) and reproducibility to investigate differences in bacterial communities in a silt loam soil. Replicate CD DGGE profiles from plates inoculated with less-dilute samples (10⁻³) had a higher band count and were more similar (72-77%) than profiles from more-dilute samples (51-61%). Different culture media and incubation conditions resulted in distinct community fingerprints and increased the cumulative number of unique bands detected. When CD DGGE fingerprints were compared to profiles constructed from 16S rRNA genes obtained from culture-independent clone libraries (CB DGGE profiles) 34% of the bands were unique to the culture-dependent profiles, 32% were unique to the culture-independent profiles and 34% were found in both communities. These data demonstrate that culture-independent DGGE profiles are supplemented by the distinct bands detected in culture-dependent profiles. CD DGGE can be a useful technique to follow the dynamics of distinct culturable fractions of the soil bacterial community.     

Detection of bacterial contamination and DNA quantification in stored blood units in 2 veterinary hospital blood banks

Blood transfusions in veterinary medicine have become increasingly more common and are now an integral part of lifesaving and advanced treatment in small and large animals. Important risks associated with transfusion of blood products include the transmission of various infectious diseases. Several guidelines suggest what infectious agents to screen for in canine and feline transfusion medicine. However, while the risk of bacterial contamination of blood products during storage and administration has not been documented in veterinary medicine, it has emerged as a cause of morbidity and mortality in human transfusion medicine. Clinical experience shows that the majority of blood component bacterial contaminations are caused by only a few species. Unlike other types of bacteria, psychrotolerant species like Pseudomonas spp. and Serratia spp. can proliferate during the storage of blood units at 4°C from a very low titer at the time of blood collection to a clinically significant level (> 10⁵ CFU/mL) causing clinical sepsis resulting from red blood cell concentrate transfusions in human medicine. The purpose of this report was to describe the detection and quantification procedures applied in 4 cases of bacterial contamination of canine and feline blood units, which suggest the need for further investigations to optimize patients’ safety in veterinary transfusion medicine.     

中华鳖穿孔病病理变化

本文报道由嗜水气单胞菌、普通变形菌等多种细菌引起的中华鳖穿孔病的病理变化。病鳖各脏器发生变质性病变,充血、出血,呈败血症;脏器局部坏死组织中聚有大量脓细胞,呈化脓灶。同健康鳖相比,病鳖１２项血清生化成分有８项发生显著变化：Ｋ＋、Ｃａ２＋、谷草转氨酶和乳酸脱氢酶量增多;Ｎａ＋、Ｃｌ－、胆固醇和碱性磷酸酶量减少;肌肉中酯酶和肝脏中超氧化物歧化酶活性降低。     

长白赤松和红松土壤微生物活性对高浓度CO_2的响应(英文)

研究了2003 年夏季长白赤松和红松土壤微生物活性对高浓度CO2的响应规律。结果表明,长白赤松和红松土壤细菌数量受高浓度CO2影响显著(p < 0.05)减少;与对照箱(350 μmol ·mol-1 CO2)和裸地(350 μmol ·mol-1 CO2)相比,红松土壤淀粉酶和转化酶活性降低,而长白赤松土壤淀粉酶和转化酶活性却表现为增加;同时发现受700 μmol ·mol-1 CO2处理的红松和长白赤松土壤微生物生物量碳均表现为显著降低。DGGE 结果表明:受高浓度CO2 的影响,长白赤松和红松土壤细菌群落结构发生了明显的变化。研究结果表明土壤微生物对高浓度CO2的响应规律与所研究的的树种有关。图2 表2 参29。