Identification of Peanut Green Mosaic Virus Strains in India*

During field surveys, three peanut green mosaic virus isolates differing in symptomatology on groundnut and a few other hosts were collected. Ultrathin sections of infected groundnut leaflets showed cytoplasmic inclusions with pin wheels and scrolls. In enzyme-linked immunosorbent assay they reacted strongly with antisera to peanut green mosaic and soybean mosaic virus antisera, and moderately with adzuki bean mosaic and peanut stripe virus antisera. All isolates also reacted positively with antisera to peanut eye spot, blackeye cowpea mosaic, pea seed-borne mosaic, potato virus Y and tobacco etch viruses, and did not react with antisera to peanut mottle, bean yellow mosaic, bean common mosaic, clover yellow vein and sugarcane mosaic viruses. SDS-PAGE analysis of purified virus preparations of the three isolates showed a single polypeptide with mol. wt. of 34,500 daltons. Based on these results, the three isolates are identified as biologically distinct strains of peanut green mosaic virus.     

Peanut Chlorotic Ringspot Virus (PCRV), a Newly Discovered Virus Infecting Peanut (Arachis hypogaea L.)

A virus causing wide chlorotic ringspot (PCRV) associated with chlorotic line pattern and motthng on an Erictoides hybrid growing in USDA-OSU greenhouses, Stillwater, Oklahoma, was discovered. The virus was isolated and characterized and found to differ in symptomology, host range and serological properties from all the previously described viruses infecting peanut, particularly those reported in the United States to be the most important ones, peanut mottle virus, peanut stripe virus, and tomato spotted wilt virus. The virus was transmitted by both mechanical inoctilation and grafting to fourteen peanut cultivars causing identical symptoms to those originally observed on the Erictoides hybrid. In addition to peanut, the virus systemically infected Pisum sativum L. ‘Little marvel’ causing mainly mosaic and Lupinus albus L. ‘Tiftwhite’ producing severe malformation and remarkable reduction in leaflet area. The virus did not infect many other plant species of which cowpea ‘California blackeye’ (Vigna unguiculata L.) and at least five cultivars of soybean (Glydne max L.) are known to be susceptible hosts to peanut mottle virus. Phaseolus vulgaris L. ‘Topcrop’ and Chenopodium amaranticohr Coste & Reyn were found to be two useful local lesion assay and diagnostic hosts for PCRV. The virus elicited necrotic local lesions on the first and chlorotic ringspots on the second. PCRV had a dilution end point between 10^?5 and 10^?6, thermal inactivation point between 55°C and 60°C, and longevity in vitro up to 6 days but not 7 days. Virus particles viewed hy electron microscopy and the negative stain uranyl aceute were flexuous filamentous particles ranging in length from 750–850 nm. In both indiren PAS-ELISA and Ouchterlony double immunodiffusion test, PCRV was serologically related to a PMV isolate from Oklahoma (PMV-OK.) but not to bean yellow mosaic virus, peanut stripe virus, potato virus Y, watermelon mosaic virus 1, watermelon mosaic virus 2, wheat streak mosaic virus, and zucchini yellow mosaic virus.     

A Strain of Eggplant Mosaic Virus Causing a Severe Disease of Tomato in Argentina

A virus causing a severe disease of tomatoes in Argentina was identified as a strain of eggplant mosaic virus (EMV). It resembles the type, Abelia latent and various Andean potato latent strains of EMV in its host range and its transmissibility at allow rate by Epitrix sp. It differs from these strains, however, serologically and in some of its cytopathic effects. In serological agar gel double diffusion tests it proved to be closely related to the tomato white necrosis isolate of EMV studied by Barradas (1983) in Brazil.     

Isolation and Partial Characterization of Peanut Top Paralysis Virus (PTPV), a Destructive Virus Causing a New Disease in Peanut (Arachis hypogaea L.)

A destructive virus, causing top paralysis to peanut, was discovered in the wild germplasm collection growing in the USDA-ARS greenhouses, Stillwater, Oklahoma, USA. The symptoms observed on the wild plant were restricted to a few leaves as green batches in a light green to yellow background with some leaflets having lost most of the basal part of the laminae leaving the top portion rolling upwards forming a cone. The virus was mechanically transmitted to cultivated peanut ( Arachis hypogaea L,.) where it caused more severe and destructive symptoms including stunting, severe malformation of leaves and partial or complete disappearance of leaflet laminae. This virus differed in symptomology, host range, and/or serological reactivity from allpeanut viruses reported in the literature, particularly those causing leaf malformation and stunting. The virus induced necrotic local lesions on Phaseolus vulgaris L. cv. "Topcrop" and chlorotic local lesions with necrotic centres bordered withvery bright intense red color on Chenopodium amaranticolor. In both passive indirect enzyme-linked immunosorbent assay (PAS-ELISA) and Ouchterlony double immunodiffusion test, the virus did not react with antisera against brome mosaic, bean yellow mosaic, peanut stripe, potato Y, tobacco mosaic, watermelon mosaic 1, watermelon mosaic 2, wheat soilborne mosaic, wheat streak mosaic, and zucchini yellow mosaic viruses.
However, in reciprocal cross reactions the virus seemed to share a common antigenic determinant with a peanut mottle virus isolate from Oklahoma (PMV-OK). The virus had flexuous filamentous particles with a length of 750–850 nm, falling within the range reported for the potyvirus group. The virus was successfully purified and the molecular weight of its protein subunit was found to be 30000 d. A polyclonal antiserum was raised in rabbits against the virus and used for reciprocal serological tests.     

A New Strain of Cucumber Mosaic Virus Causing Mosaic Disease of Muskmelon

The virus causing mosaic of muskmelon in the Punjab is transmitted through seed, sap and aphids but not through beetle, whitefly, fungi or contact. It systemically infected Nicotiana tabacum (var. “White Burley” and CTRI-Special), N. glutinosa, N. rustica and Capsicum annuum besides various cucurbit hosts when inoculated mechanically. The virus gave positive reaction with the antiserum of cucumber mosaic virus and the particles are spherical in shape. The virus has been identified as a distinct strain of cucumber mosaic virus and is designated as muskmelon strain of cucumber mosaic virus (CMV-mst.).     

Biological, Serological and Coat Protein Properties of a Strain of Turnip Mosaic Virus Causing a Mosaic Disease of Brassica campestris and B. juncea in India

Biological, serological and coat protein properties of a potyvirus (Poty-Rape) causing a mosaic disease of Brassica campestris and B. juncea in India were investigated. The virus readily infected 4 of the 5 plant species in the family Brassicaceae in which it induced severe systemic mosaic symptoms; it also induced chlorotic and necrotic local lesions in Chenopodium amaranticolor , but failed to infect 4 other species of Chenopodiaceae or 20 species of Amaranthaceae, Apiaceae, Canabinaceae, Compositae, Cucurbitaceae, Euphorbiaceae, Leguminosae and Solanaceae. The virus was transmitted in a non-persistant manner by Myzus persicae, Brevicoryne brassicae and Aphis gossypii. The Average size, of the virus particles in a purified preparation was 740 nm × 12 nm. SDS-PAGE analysis of the viral coat protein showed two major bands of approximately 37 kDa and 31 kDa, a pattern very similar to that of a reference isolate of turnip mosaic virus (TuMV) from the U.S. In Western-blot immunoassay, an antiserum to TuMV reacted with both the coat protein bands of the Poty-Rape islate and the reference TuMV, but not with the coat proteins of four other potyviruses. The high performance liquid chromatographic profile of tryptic peptides from the coat protein of Poty-Rape was found to be very similar to that of the reference TuMV, but differed substantially from those of four other potyviruses. The Poty-Rape isolate is considered to be a distinct strain of, TuMV.     

浙江1株水稻细菌性条斑病菌株的分离鉴定

细菌性条斑病(简称细条病)是水稻的重要病害之一,随着气候的变暖,某些水稻品种有逐年发生加重的趋势,对产量影响较大。2013年浙江省金华市部分水稻种植区域发生细条病,发病严重的田块减产30%以上。采用组织分离法从发病水稻叶片分离获得6株细菌菌株,选择典型菌株JH01回接水稻幼苗,进行柯赫法则验证。接种后发病症状与自然发病症状一致,并重新分离得到此菌株,证明菌株JH01为水稻细条病的致病菌。通过形态学观察、常规生理生化指标测定、16S rDNA 序列测定和同源性分析,鉴定菌株JH01为稻黄单胞菌水稻致病变种（Xanthomonas oryzae pv. oryzicola,Xoc）。     

1株高效花生根瘤菌的筛选与鉴定

从辽宁多地花生种植土壤及其鲜根瘤初步筛选到30株花生根瘤菌,进一步通过回接盆栽花生,测定花生根瘤数、根瘤干重,以及鲜根瘤固氮酶活性、植株全氮量等,筛选出1株结瘤固氮能力较强花生根瘤菌wz-6,通过16S rDNA序列分析,鉴定为圆明慢生根瘤菌(Bradyrhizobium yuanmingense)。为开发优质花生根瘤菌菌剂奠定基础。     

Complete Genome Sequence of Mulberry Vein Banding Associated Virus,a New Tospovirus Infecting Mulberry

Mulberry vein banding associated virus (MVBaV) that infects mulberry plants with typical vein banding symptoms had been identified as a tentative species of the genus Tospovirus based on the homology of N gene sequence to those of tospoviruses. In this study, the complete sequence of the tripartite RNA genome of MVBaV was determined and analyzed. The L RNA has 8905 nucleotides (nt) and encodes the putative RNA-dependent RNA polymerase (RdRp) of 2877 aa amino acids (aa) in the viral complementary (vc) strand. The RdRp of MVBaV shares the highest aa sequence identity (85.9%) with that of Watermelon silver mottle virus (WSMoV), and contains conserved motifs shared with those of the species of the genus Tospovirus. The M RNA contains 4731 nt and codes in ambisense arrangement for the NSm protein of 309 aa in the sense strand and the Gn/Gc glycoprotein precursor (GP) of 1,124 aa in the vc strand. The NSm and GP of MVBaV share the highest aa sequence identities with those of Capsicum chlorosis virus (CaCV) and Groundnut bud necrosis virus (GBNV) (83.2% and 84.3%, respectively). The S RNA is 3294 nt in length and contains two open reading frames (ORFs) in an ambisense coding strategy, encoding a 439-aa non-structural protein (NSs) and the 277-aa nucleocapsid protein (N), respectively. The NSs and N also share the highest aa sequence identity (71.1% and 74.4%, respectively) with those of CaCV. Phylogenetic analysis of the RdRp, NSm, GP, NSs, and N proteins showed that MVBaV is most closely related to CaCV and GBNV and that these proteins cluster with those of the WSMoV serogroup, and that MVBaV seems to be a species bridging the two subgroups within the WSMoV serogroup of tospoviruses in evolutionary aspect, suggesting that MVBaV represents a distinct tospovirus. Analysis of S RNA sequence uncovered the highly conserved 5’-/3’-ends and the coding regions, and the variable region of IGR with divergent patterns among MVBaV isolates.     

Identification and Characterization of a Distinct Strain of Beak and Feather Disease Virus in Southeast China

Beak and feather disease virus(BFDV) is an infectious agent responsible for feather degeneration and beak deformation in birds. In March 2017, an epidemic of psittacine beak and feather disease(PBFD) struck a farm in Fuzhou in the Fujian Province of southeast China, resulting in the death of 51 parrots. In this study, the disease was diagnosed and the pathogen was identified by PCR and whole genome sequencing. A distinct BFDV strain was identified and named as the FZ strain.This BFDV strain caused severe disease symptoms and pathological changes characteristic of typical PBFD in parrots, for example, loss of feathers and deformities of the beak and claws, and severe pathological changes in multiple organs of the infected birds. Phylogenetic analysis showed that the FZ strain was more closely related to the strain circulating in New Caledonia than the strains previously reported in China. Nucleotide homology between the FZ strain and other 43 strains of BFDV ranged from 80.0% to 92.0%. Blind passage experiment showed that this strain had limited replication capability in SPF Chicken Embryos and DF-1 Cells. Furthermore, the capsid(Cap) gene of this FZ strain was cloned into the p GEX-4 T-1 expression vector to prepare the polyclonal anti-Cap antibody. Western blotting analysis using the anti-Cap antibody further confirmed that the diseased parrots were infected with BFDV. In this study, a PBFD and its pathogen was identified for the first time in Fujian Province of China, suggesting that future surveillance of BFDV should be performed.     

Characterization of a Novel Virus Causing a Lethal Disease in Carp and Koi

Since 1998 a lethal disease of carp and ornamental koi (Cyprinus carpio) has afflicted fisheries in North America, Europe, and Asia, causing severe economic losses to the fish farming industry. This review summarizes the isolation and identification of the disease-causing agent and describes the currently known molecular characteristics of this newly isolated virus, distinguishing it from other known large DNA viruses. In addition, we summarize the clinical and histopathological manifestations of the disease. Providing information on the immune response to this virus and evaluating the available means of diagnosis and protection should help to reduce the damage induced by this disease. This review does not discuss the economic aspects of the disease or the debate on whether the disease should be registered; both of these issues were recently reviewed in detail (O. L. M. Haenen, K. Way, S. M. Bergmann, and E. Ariel, Bull. Eur. Assoc. Fish Pathol. 24:293-307, 2004; D. Pokorova, T. Vesely, V. Piackova, S. Reschova, and J. Hulova, Vet. Med. Czech. 50:139-147, 2005).     

Characterization of Maize Chlorotic Mottle Virus Associated with Maize Lethal Necrosis Disease in China

A maize lethal necrosis disease was observed in Yunnan province of China. Isometric virus particles 30 nm in diameter were found in infected maize leaf tissues. Using DAS‐ELISA, diseased maize plant samples reacted positively with the antiserum of Maize chlorotic mottle virus (MCMV). The complete nucleotide sequence (4436 nt) of a Yunnan isolate of MCMV was determined; it shares 97% nucleotide sequence identity with previously reported MCMV isolates. This is the first report of MCMV occurring in China.     

流行性感冒病毒鸡胚高产株的遗传特性分析

流行性感冒（流感）病毒的基因组由分节段的单股负链RNA组成,其中A、B型流感病毒含8个基因节段［1］。它的第4和第6节段分别编码病毒的血凝素（HA）和神经氨酸酶（NA）,决定病毒的抗原性,其它6个节段与病毒的生长特性有关［2］。在流感疫苗生产中,为了提高产量,利用高产毒株与流行毒株基因重配获得重组病毒,它含有流行毒株的第4、第6节段和高产毒株的其它6个节段,这样既具有流行毒株的抗原性又具有高产特性,可以用来降低疫苗的生产成本。     

Further Studies on a Virus Causing a Green Mosaic Disease of Eggplant in Nigeria

A virus reported earlier to cause a green mosaic disease of eggplant in Nigeria was studied in more detail. Its filamentous particles with a normal length of 820 nm reacted in immunoelectron microscopical tests strongly with the homologous antiserum and less strongly with antisera to dioscorea green banding mosaic, groundnut eyespot, zucchini yellow mosaic viruses and to a tomato potyvirus isolate from Taiwan. No reactions were seen with antisera to 25 other potyviruses. Several new host plants were identified. Infected cells contained cylindrical inclusions with scrolls and short curved laminated aggregates and clusters of small vesicles with electron-dense content. Host range and serological reactivities differentiate the virus for which the name eggplant green mosaic virus is suggested from all potyviruses so far known.     

Complete Genome Sequence of Newcastle Disease Virus Mesogenic Vaccine Strain R2B from India

Mesogenic vaccine strains of Newcastle disease virus (NDV) are widely used in many countries of Asia and Africa to control the Newcastle disease of poultry. In India, the mesogenic strain R2B was introduced in 1945; it protects adult chickens that have been preimmunized with a lentogenic vaccine virus and provides long-lasting immunity. In this article, we report the complete genome sequence of the hitherto unsequenced Indian vaccine virus strain R2B. The viral genome is 15,186 nucleotides in length and contains the polybasic amino acid motif in the fusion protein cleavage site, indicating that this vaccine strain has evolved from a virulent virus. Phylogenetic analysis of this mesogenic vaccine virus classified it with the viruses belonging to genotype III of the class cluster II of NDV.