南京农业发展思路的定位分析

阐述了农业发展思路中定位的重要性，认为南京农业发展应定位于市场资源型、现代城郊型与都市开发型等３个层次。     

Hepatozoon canis: The prevalence of antibodies and gametocytes in dogs in Israel

A survey for the prevalence of antibodies to Hepatozoon canis and for intraneutrophilic H. canis gametocytes in the peripheral blood neutrophils of dogs in Israel showed that 33.1% were seropositive, while only 1% of the dogs sampled had detectable parasites in their blood smears. Exposure to H. canis is widespread but it appears that most infected dogs undergo a subclinical infection and only a small proportion develop clinical disease.Abbreviations IFAT indirect fluorescent antibody test     

The pathogenesis of experimental Haemonchus longistipes infection in camels

The pathogenesis and clinical signs of Haemonchus longistipes infection were studied in four experimentally infected camels two of which were adults and the other two were young. In the former animals, an acute infection developed, characterized by mucoid diarrhoea, anorexia, anaemia, loss of body weight, oedema of the lower parts of the limbs, general malaise and death at 8-10 weeks post-infection. In the two younger camels, a less dramatic disease was encountered with less severe symptoms and no oedema, but also terminating fatally at 19-20 weeks post-infection. Parasitological, haematological and biochemical parameters were determined during the course of the infection and were mostly comparable with those usually encountered in haemonchosis of other animals.     

Electrophoretic comparison of the genomes of North American bluetongue viruses, one Australian bluetongue virus, and three other related orbiviruses

The genomes of U.S. bluetongue viruses, an Australian bluetongue virus, and three other related orbiviruses were analyzed by polyacrylamide gel electrophoresis. The genomes were comprised of ten segments of double-stranded (ds) RNA. Estimates of the molecular weights of the dsRNA segments revealed that the U.S. bluetongue serotypes were remarkably similar. Although the dsRNA profiles of the viruses exhibited common segments, each virus had a distinct dsRNA profile. The usefulness of the genome analysis as a diagnostic tool for identification and for epidemiologic studies is discussed.     

应用ELISA检测绵羊抗东毕吸虫抗体

用东毕吸虫成虫,经葡聚糖凝胶G—100层析柱制备纯化抗原,应用ELISA间接法检测自然感染东毕吸虫绵羊的抗体,同时,配合沉淀法、孵化法和全身剖检法进行检查,显示阳性符合率为98.4％,阴性符合率为95％;除与肝片吸虫阳性血清有4.8%的交叉反应外,未发现与矛形双腔吸虫阳性血清和前后盘吸虫阳性血清有交叉反应;ELISA的阳性检出率高于沉淀法和孵化法;并证明东毕吸虫感染强度与血清抗体无相关关系。     

Dairy farm wells in southeastern Minnesota: The relation of new water sources (new wells) to milk and milk fat production

Milk and milk fat production per cow were studied on 17 Fillmore County, Minnesota, Dairy Herd Improvement Association dairies before and after the source of drinking water for cows was changed by the drilling of a new well. New wells were in deeper aquifers which were more protected from waterborne pollutants; the former wells were in shallow, easily polluted aquifers. Seventeen other dairies with swallow wells served as controls, matched for pre-well milk production per cow, dairy location, and breed of cow. The changes in milk and milk fat production per cow after the drillingof a new well were not statistically significant.     

The activity of closantel as an equine antiparasitic agent

Eighteen pony foals were experimentally infected with 500 third stage larvae of Strongylus vulgaris at 2 weeks, and at 2, 4, 6 and 8 months after birth. For the duration of the study, all foals were kept in the same pasture with their mothers to allow natural infection with other parasites by exposure to a contaminated environment. Twelve of the foals were utilized in groups of 3 and treated orally five times at two month intervals starting at one month of age with closantel at doses of 5, 10, 20 or 40 mg kg-1. Ten months after birth the foals were necropsied to determine the parasitic burdens in the gastrointestinal tracts and the cranial mesenteric arteries. The results indicate a high antiparasitic activity of closantel against larval stages of Gasterophilus intestinalis and S. vulgaris, as well as against adult S. vulgaris, S. edentatus, Anoplocephala perfoliata and Triodontophorus spp., when used at doses of 20 or 40 mg kg-1.     

抗TYLCV 番茄新品种龙番1 号的选育

龙番1 号是以自交系TMX2511-2 为母本，以自交系TMX2535-4 为父本配制而成的抗TYLCV 番茄一代杂种。无 限生长类型，植株生长势强，始花节位为第8～9 节；果实红色，扁圆形，纵径6.5～7.0 cm，横径8.0～8.5 cm，单果质量 220 g 左右，果实硬度中等，幼果无绿肩；果实可溶性固形物含量5.9%，番茄红素含量0.035 mg · g^-1，VC 含量0.167 mg · g^-1， 一般每667 m² 产量8 500 kg 左右，高抗番茄黄化曲叶病毒病（TYLCV），抗叶霉病，中抗黄瓜花叶病毒病（CMV）、根结线虫， 适宜山西省吕梁、忻州、晋中、长治、大同等地春提早、秋延后塑料大棚种植。     

Survival and infectivity of Dicrocoelium dendriticum eggs under field conditions in NW Spain

A study was made of the survival of Dicrocoelium dendriticum eggs in sheep faeces in an area with a temperate climate (NW Spain). It appears that mortality is independent of the age of the eggs and that there is a marked seasonality within the period of time considered (20 months). A study was also carried out on the infectivity of D. dendriticum eggs by experimental infections of suitable intermediate hosts. The data show that no loss took place in infectivity during the period of study (15 months).     

Decreased sensitivity to pyrazophos of cucumber and gherkin powdery mildew

In some cucumber and gherkin greenhouses in the Netherlands, where Curamil (a.i. pyrazophos) had been used for control of powdery mildew, unsatisfactory disease control was obtained in recent years. Laboratory tests revealed a decreased sensitivity of the pathogen to the fungicide. The fitness and the competitive ability of pyrazophos resistant strains in absence of the fungicide appeared to be somewhat lower than that of the normal, sensitive strains. The implications with respect to disease control in practice are discussed.Samenvatting In enkele kassen, waar Curamil (a.i. pyrazofos) in 1977 aangewend werd ter bestrijding van meeldauw op komkommers en augurken, werd onvoldoende effekt met dit middel tegen deze ziekte verkregen. Toetsing in het laboratorium bracht een verminderde gevoeligheid van het pathogeen voor het fungicide aan het licht (Tabel 1). Bij afwezigheid van pyrazofos bleek het competitief vermogen (Tabel 2) en de vitaliteit (Tabel 3) van de pyrazofos resistente isolaten wat lager te zijn dan die van het normale, gevoelige pathogeen. De betekenis hiervan met betrekking tot de ziektebestrijding wordt besproken.