The isolation and identification of rhubarb viruses occurring in Britain

Virus-like symptoms were common in British crops of rhubarb. All plants tested of the three main varieties, ‘Timperley Early’, ‘Prince Albert’ and ‘Victoria’, were virus-infected. Turnip mosaic virus and a severe isolate of arabis mosaic virus (AMV) were obtained from ‘Timperley Early’; and ‘Prince Albert’ contained turnip mosaic virus, cherry leaf roll virus (CLRV), a mild isolate of AMV and, infrequently, cucumber mosaic virus (CMV). The main commercial variety ‘Victoria’ contained turnip mosaic virus, CLRV, a mild isolate of AMV and, infrequently, strawberry latent ringspot virus (SLRV). All the viruses were identified serologically. The rhubarb isolates did not differ markedly from other isolates of these viruses in herbaceous host reactions, properties in vitro or particle size and shape. A rhubarb isolate of CLRV was distinguished serologically from a cherry isolate of the virus. Turnip mosaic virus, CLRV and SLRV, were transmitted with difficulty, but AMV isolates were readily transmitted by mechanical inoculation. Turnip mosaic virus was also transmitted to rhubarb by Myzus persicae and Aphis fabae. CLRV was transmitted in 6–8% of the seed of infected ‘Prince Albert’ and ‘Victoria’ rhubarb and in 72% of the seed of infected Chenopodium amaranticolor. Mild isolates of AMV were also transmitted in 10–24% of the seed of infected ‘Prince Albert’ and ‘Victoria’ plants.     

The prevalence of viruses of honey bees in Britain

Adult individuals of honey bee colonies in Britain are commonly infected with several small RNA viruses. Black queen cell virus and bee virus Y are the commonest and occur most frequently about June, together with Nosema apis with which both viruses are intimately but independently associated. Bee virus X is less common than bee virus Y and showed no pronounced seasonal fluctuations in local surveys, but was detected mostly in winter and early spring. Sacbrood virus occurred in adults of most local colonies in summer, chronic paralysis virus and cloudy wing particle occurred commonly but without seasonal variations and acute paralysis occurred commonly throughout the active season of bees but does not multiply sufficiently to cause overt disease. Slow paralysis virus was rare.     

Development of a practicable method for isolation and identification of dengue viruses in developing countries

We sought a practicable method for isolation and identification of dengue viruses in South-East Asia. We compared two mosquito cell lines, C6/36 and TRA-284-SFG, for virus isolation and two identification methods, immunofluorescent staining of infected cells with serotype-specific mouse monoclonal antibodies and a sandwich-type enzyme-linked immunosorbent assay with conventional mouse hyperimmune ascitic fluids. We found that the combination of TRA-284-SFG cells and ELISA is a useful and feasible method in developing countries.     

Aphid-transmitted viruses from lilies in Britain

Three aphid-transmitted viruses, tulip breaking, lily symptomless and cucumber mosaic, were obtained from lilies in Britain. Tulip breaking virus was detected by the leaf mottle produced in Lilium formosanum, cucumber mosaic virus by inoculation of sap to Nicotiana clevelandii and Chenopodium quinoa, and lily symptomless virus by electron microscopy of crude leaf extracts from symptomless L. formosanum. Liiy symptomless virus was transmitted by Myzus persicae, Macrosiphum euphorbiae, Aulacorthum solani and Aphis fabae. M. persicae, which in a small experiment appeared a more efficient vector than A. fabae, transmitted the virus in a non-persistent manner. This conflicts with the original report of transmission in a persistent manner by A. gossypii but no transmission by M. persicae. The possibility that there are two distinct viruses with similar pathological effects is discussed. Tulip breaking and lily symptomless viruses spread to bait plants of L. formosanum within a field planting of lilies in Scotland especially during July to September; lily symptomless virus was the more prevalent. No spread of cucumber mosaic virus was detected.     

新型鸭呼肠孤病毒的分离与鉴定

本研究从临床表现为出血性坏死性肝炎的病死鸭肝脾中分离到病毒。病原特性鉴定显示,分离毒能致死番鸭胚和鸡胚;人工感染1日龄雏番鸭、雏半番鸭均能复制出与临床自然发病鸭相同的临床症状和病理变化,并能回收到病毒。分离毒能在MDEF等多种细胞中增殖并产生细胞病变。电镜下病毒在细胞浆中呈大量散在、成堆和晶格状排列,病毒粒子呈球形、无囊膜、双层衣壳、直径70nm左右。在SDS-PAGE中具有禽呼肠孤病毒10个RNA片段的特征,但M1-3和S1-4片段的迁移率明显不同于番鸭呼肠孤病毒(MDRV)。分离毒S3基因全序列与禽呼肠孤病毒(ARV)、火鸡呼肠孤病毒(TRV)和MDRV的核苷酸同源性分别为60%～60.2%,61.9%,62.3%～62.7%,氨基酸同源性分别为68.2%～69%,68.2%,69.3%～70.1%;S3基因编码的σB蛋白属于单独的进化分支,提示分离毒S3基因具有不同于ARV和MDRV的特征。结果表明鸭出血性坏死性肝炎的病原是一种属于呼肠孤病毒科正呼肠孤病毒属新型鸭呼肠孤病毒。     

The identification of hymenopterous parasitoids attacking cereal aphids in Britain

Abstract. Keys are provided to assist in the identification of the hymenopterous parasitoids which attack cereal aphids in Britain, and brief notes are given on both the primary parasitoids and the hyperparasitoids.     

噬菌蛭弧菌的分离及初步鉴定

采用双层平板法,以滤膜过滤的方法来收集噬菌蛭弧菌,以嗜水气单胞菌(Aeromonas hudrophila)、荧光假单胞菌(Pseudomonas fluorescent)和绿脓杆菌(Pseudomonas aeruginosa)为宿主菌,进行噬菌蛭弧菌的分离研究;并在此基础上,通过接触酶检测和寄生性确认对噬菌蛭弧菌(Bdellovibrio bacteriovorus)进行了初步的鉴定.结果表明未使用滤膜过滤,采用自来水琼脂双层平板法分离噬菌蛭弧菌的效果较好;并经过接触酶和寄生性检测初步鉴定此BD-SPOI菌株为噬菌蛭弧菌.     

菜青虫幼虫肠道细菌的分离及鉴定

目的为深入研究菜青虫肠道的营养生理,分析其取食消化机制,对菜青虫肠道细菌进行了研究。方法从自然种群的菜青虫肠道环境中按传统分离、纯化、培养,获得细菌5个菌株,对其茵体形态、染色反应、培养性状、生理生化反应进行了系统研究。结果鉴定结果l号菌株为李斯特菌属（Listeria）,2号菌株为皮杆菌属（Dermabacter）,3号菌株为丙酸杆菌属（Propionibacterium）,4号菌株为沙雷菌属（Serratia）,5号菌株为短状杆菌属（Brachybacterium）。结论在菜青虫肠道环境中分离出5个菌株,鉴定出分类地位。其菌株之间的数量具有明显差异,以皮杆菌属数量最多（2×10^8）,需进一步研究该菌的功能及其在菜青虫肠道中的作用。