03-05年福州地区PCV2的流行病学调查

我国从2000年至今,在上海、湖南、河南、湖北、江西、浙江、黑龙江等地陆续报道存在PCV2的血清学阳性,总阳性率在40%-80%。可见该病毒在国内普遍感染。本文就福州地区2003年至2005年八个县(市、区)规模化猪场PCV2的血清学、病原学、临床症状进行调查,现报告如下。1血清学调查1.1样品来源:2003年到2005年本地区八个县(市、区)41个猪场1171份血清。1.2检测方法:酶联免疫吸附试验。1.3诊断试剂:猪圆环病毒病酶联免疫诊断试剂盒,购自华中农业大学动物学院动物病毒室,批号分别为20031015、20040517、200507。1.4操作方法:见试剂盒内的说明。1.…     

2003～2005年河南省鸡传染性法氏囊病流行病学调查

对2003～2005年间河南省15个地区鸡群传染性法氏囊病的流行情况进行了调查。发现传染性法氏囊病的发病有全年化趋势,但每年仍以6～9月份为发病高峰期;发病鸡的日龄范围扩大;病变以法氏囊呈胶胨样水肿和肾脏尿酸盐沉积为主要特征,二者出现率分别占67.2%和73.11%,其它病变多不典型;发病鸡群中免疫鸡群占78.17%;二次发病鸡群约占16.98%;宿主和易感群体的范围扩大。对出现上述情况进行了初步的分析并提出相应的措施。     

绿柳突瓣叶蜂生物学及防治

绿柳突瓣叶蜂(Nematus ruyanus Wei)是发生在甘肃天水柳树上的一种新害虫。严重危害旱柳、垂柳、金丝柳等多种柳树,1年发生6代,非越冬茧结于叶背,越冬茧结于1-5 cm表土中,以预蛹在越冬茧内越冬。幼虫食叶危害,每年3月下旬至10月下旬是该虫的猖獗危害期。用25%灭幼脲,1.8%阿维菌素乳油,40%氧乐果乳油2000倍液防治3龄前幼虫防效达95%以上;用2.5%溴氰菊酯乳油,3%高渗苯氧威乳油4000倍液喷冠防治3龄后大幼虫防效可达90%以上。     

云南省昆明市动物园大肠杆菌分离株毒力基因分布特征

为研究云南省昆明市动物园动物体内大肠杆菌(E.coli)分离株毒力基因的分布特征,从圆通山动物园37个动物种群粪便中分离出37株E.coli,采用生化鉴定方法鉴定大肠杆菌,PCR方法检测19种毒力基因。鉴定结果表明:37株E.coli中,ompA、iroN、fimC、aatA、vat 5种毒力基因携带率分别为100%、95.49%、83.78%、70.27%、51.35%,ibeA、neuC、iutA、traT、stx 5种毒力基因携带率为0,其他9种毒力基因携带率均低于40.00%;分离菌株普遍携带8种以下毒力基因,同时携带10种以上毒力基因的概率为8.10%;分离株强毒力岛基因携带率较高,分布较为普遍。结果表明,昆明市圆通山动物园内流行的大肠杆菌以致病性大肠杆菌为主,不同种类动物体内大肠杆菌的毒力基因携带率存在较大差异,其原因可能与动物的饲养环境以及动物自身的适应能力和抵抗力有关。因此,对于动物园内具有较高大肠杆菌致病风险的动物,要采取相应防治措施,防止大肠杆菌病发生与流行。     

基于SRAP分子标记的11份柑橘种质材料遗传多样性分析

为分析11份柑橘种质材料的遗传多样性,本研究以7份沙糖橘种质以及4份其他柑橘种质为试验材料,利用SRAP分子标记进行分析,并用UPGMA法进行聚类.结果表明:160对引物组合筛选出20对引物组合扩增条带清晰,11份种质材料两两之间遗传相似系数在0.322 1～0.931 6之间.沙糖橘和金葵蜜橘间的遗传相似系数最大,为...     

甘薯根腐病抗性在不同环境条件下的表现及遗传趋势

结果表明,甘薯根腐病发病轻重与环境条件有很大关系,表现为干旱少雨的年份发病较重,降雨量较多的年份发病较轻;土壤瘠薄的发病较重,肥力条件较好的则发病较轻;通常情况下,年份间品种的抗性表现较为一致,但遇特殊气候则年份间品种的抗性有一定的差异。对1150份甘薯品种资源及育种材料的根腐病抗性鉴定结果表明,高抗型材料占14.6％,抗病型占15.7％,感病型占26.0％,高感型占43.7％。对754份材料及亲本的抗性分析表明,不同的抗性组合后代中均可分离出高抗至高感类型的材料,杂交后代的抗性强弱随双亲抗性水平的提高而提高。中国自1970年以来采用品种间杂交和种间杂交育种技术,先后育成了一批高产、优质的高抗型优良品种。     

贵州省水城县森林防火中存在的问题及对策

分析贵州省水城县森林火灾易发的原因,并提出相应的森林防火对策.     

Rapid identification of virulence genes in enterotoxigenic Escherichia coli isolates associated with diarrhoea in Queensland piggeries

OBJECTIVE: To identify virulence genes in enterotoxigenic E coli (ETEC) isolates associated with diarrhoea in neonatal, 1 to 3 week-old and weaned pigs in southeast Queensland. DESIGN: Multiplex PCR and serotyping were applied to E coli isolates obtained over a 5-year period (1998-2002) from cases diagnosed at Toowoomba Veterinary Laboratory. PROCEDURE: A total of 126 isolates from 25 different Queensland piggeries were tested for haemolytic activity on 5% sheep blood agar and by multiplex PCR for the presence of five commonly recognised fimbrial (F4, F5, F6, F41 and F18) and three enterotoxin genes (STa, STb, LT). A subset of 62 representative isolates were serotyped by slide agglutination. For comparative purposes, multiplex PCR was also performed on the DNA of 31 ETEC isolates from 9 serotypes originating from piggeries in southern New South Wales. RESULTS: A total of 113 (89.7%) of the isolates from Queensland possessed ETEC virulence genes, including 14 of 15 isolates from neonatal pigs (93.3%), 18 of 23 isolates from 1 to 3 week old pigs (78.3%) and 81 of 88 isolates from weaned pigs (92.1%). F4:STa:STb:LT (serotype O149) was the most prevalent pathotype in neonatal and 1-3 week old pigs and F4:STa:STb:LT (serotype O149) and F18:STa:STb:LT (serotype O141) were most prevalent in weaned pigs. In comparison, isolates obtained from neonatal pigs from New South Wales belonged to a more diverse range of pathotypes and serotypes. CONCLUSION: Multiplex PCR was a rapid and specific method for detecting the presence of ETEC virulence genes in porcine E coli isolates. For isolates obtained from cases of suspected colibacillosis in Queensland, growth of a heavy pure culture of haemolytic E coli was a sensitive prognostic indicator of the presence of ETEC virulence genes in the isolate. ETEC pathotypes and serotypes remained stable in Queensland piggeries over the five-year study period and appear to have changed little over the last three decades.     

Osteological development and anomalies in larval stage of hatchery‐reared yellow catfish Pelteobagrus fulvidraco

Comprehensive knowledge of osteological development of fish not only provides means for understanding its functional development, but also allows early detection of skeletal anomalies. The present study was conducted to determine osteological development and occurrence of anomalies from the first to the 40th day after hatching (DAH) for yellow catfish Pelteobagrus fulvidraco, a commercially important species in China. Vertebral ontogeny started with formation of anterior neural arches at 3 DAH, and completed at 6 DAH. Vertebral centra started to develop at 4 DAH and ossification in all centra was visible at 15 DAH. Caudal fin appeared at 2 DAH and ossification was visible at 26 DAH. The onset of dorsal and anal fins appeared at 4 DAH and their ossifications were visible at 20 DAH. Pectoral fins were present before first feeding and formed entirely at 9 DAH, and their ossifications were visible at 21 DAH. Pelvic fins appeared at 9 DAH, and formed completely at 21 DAH. The ossification of pelvic fins was not finished until the end of the experiment (40 DAH). 24 types of skeletal anomalies were observed. About 20% of individuals showed at least one anomaly. Haemal vertebrae anomalies occurred at the highest frequency, followed by pre‐haemal, caudal vertebrae and anal fin anomalies, and caudal fin had the lowest anomalies frequency. For the first time, our study determined osteological development and anomalies incidence in larval yellow catfish, which help further investigations into rearing conditions leading to appearance of these anomalies to prevent their incidence.     

毒死蜱与氟虫腈复配对环境生物的影响研究

本文测定了毒死蜱与氟虫腈及其复配对靶标生物小菜蛾和二化螟的室内活性,对非靶标生物意大利蜜蜂、家蚕、斑马鱼的毒性。试验结果为毒死蜱对小菜蛾,二化螟,蜜蜂,斑马鱼,家蚕的LC50分别为586.2,45.97,2.482,0.723,1.749mg/L;氟虫腈对上述生物的LC50分别为0.121 4,1.038,0.025 1,0.180,2.325mg/L;复配后对上述生物的LC50分别为0.5256,5.626,1.983,0.535,1.528mg/L。复配后对小菜蛾、二化螟的共毒系数为230.6、153.3,对蜜蜂、斑马鱼、家蚕的共毒系数为11.6、103.8、117.3。