Incidence of viruses in <Emphasis Type="Italic">Alstroemeria</Emphasis> plants cultivated in Japan and characterization of <Emphasis Type="Italic">Broad bean wilt virus-2, Cucumber mosaic virus</Emphasis> and <Emphasis Type="Italic">Youcai mosaic virus</Emphasis>

Alstroemeria plants were surveyed for viruses in Japan from 2002 to 2004. Seventy-two Alstroemeria plants were collected from Aichi, Nagano, and Hokkaido prefectures and 54.2% were infected with some species of virus. The predominant virus was Alstroemeria mosaic virus, followed by Tomato spotted wilt virus, Youcai mosaic virus (YoMV), Cucumber mosaic virus (CMV), Alstroemeria virus X and Broad bean wilt virus-2 (BBWV-2). On the basis of nucleotide sequence of the coat protein genes, all four CMV isolates belong to subgroup IA. CMV isolates induced mosaic and/or necrosis on Alstroemeria. YoMV and BBWV-2 were newly identified by traits such as host range, particle morphology, and nucleotide sequence as viruses infecting Alstroemeria. A BBWV-2 isolate also induced mosaic symptoms on Alstroemeria seedlings.     

Multiple virus infections of lablab [<Emphasis Type="Italic">Lablab purpureus</Emphasis> (L.) Sweet] in Nigeria

Leaf samples of Lablab purpureus collected from two agroecological zones of Nigeria—the northern guinea savanna zone (NGSZ) and the derived savanna zone (DSZ)—were infected with viruses when serologically indexed against available antisera. Approximately 31.1 and 81.1% of the leaf samples collected from the NGSZ and DSZ, respectively, were infected. Seven viruses were found: Bean common mosaic virus (BCMV), Cowpea aphid-borne mosaic virus (CABMV), Cucumber mosaic virus (CMV), Cowpea mottle virus (CPMoV), Cowpea severe mosaic virus (CPSMV), Southern bean mosaic virus (SBMV) and Tobacco mosaic virus (TMV) were detected from samples collected from NGSZ, while CMV, CPMoV, Cowpea mosaic virus (CPMV) and CPSMV were detected from samples from DSZ.     

Leonotis nepetaefolia: An important plant virus reservoir in central Mexico

The presence of viruses in the weedLeonotis nepetaefolia in central México is reported from two field surveys.L. nepetaefolia, with viral-like symptoms such as mosaic, leaf deformation and calico, was observed growing next to cultivated fields in the Valley of Atlixco, Puebla, an important agricultural region in Mexico. The viruses harbored by this plant were characterized biologically, serologically and by molecular methods. The viruses detected wereAlfalfa mosaic virus (AMV),Cucumber mosaic virus (CMV), a satellite RNA of CMV (CMV satRNA) andTobacco mosaic virus (TMV). This last one was detected only during the first survey. CMV was the predominant virus found in both surveys, and was associated mostly to mosaic symptom. Phylogenetic analysis based on the coat protein gene sequence of CMV indicated that this isolate belongs to subgroup IA and confirmed that it is a mosaic-inducing isolate, whereas AMV belongs to subgroup II. Finally, CMV satRNA was found to be a non-necrogenic ameliorative variant, both by symptomatology and by phylogenetic analysis. Our results suggest thatL. nepetaefolia is a reservoir for several viruses in central Mexico, and given its wide distribution in several parts of the world, its role as a virus reservoir could be more general. http://www.phytoparasitica.org posting Aug. 31, 2005.     

新疆哈密瓜病毒类型及分布

 1981-1984年对新疆主要瓜产区的病毒发生情况进行了调查,可归纳为6个病毒类型。除1类型尚需进一步鉴定外,其他5类型分别属于黄瓜花叶病毒(CMV)、西瓜花叶病毒二号(WMV-2)、南瓜花叶病毒(SqMV)、烟草坏死病毒(TNV)和甜瓜叶脉坏死病毒(MVNV)。在大流行的1983年WMV-2和CMV,WMV-2和SqMV,CMV和SqMV以及WMV-2、SqMV和CMV的混合侵染率比1982年为高。各类型病毒的侵染率在不同地区也有较大的变化。     

Occurrence of viruses in field-grown pepper crops and some of their reservoir weed hosts in Samsun, Turkey

Pepper production is affected by several viral diseases in Samsun, Turkey. To determine the identity of these viruses, a total of 313 samples from field-grown peppers were collected during surveys in 1998 and 1999, and tested by enzyme linked immunosorbent assay (ELISA). Six viruses,Alfalfa mosaic virus (AMV),Cucumber mosaic virus (CMV),Potato virus Y (PVY),Tomato mosaic virus (ToMV),Tobacco mosaic virus (TMV) andTomato spotted wilt virus (TSWV) were detected in the samples. Of 313 plants tested, 42 were doubly infected, and TMV+PVY (15.4%) was the most common double infection. This is also the first report of AMV in pepper fields in Turkey. The effect of some weed species that may act as reservoir of these viruses was also investigated in the region and of 24 weed species belonging to 15 families tested, 16 were found to be infected with at least one virus.Amaranthus retroflexus (Redroot pigweed) appeared to be a common host of CMV, PVY, ToMV, TMV and TSWV, whereasHibiscus trionum (Venice mallow) was recorded as a new weed host of PVY and TSWV. The majority of weed species found to be virus infected were very common in the pepper growing areas of the region. This indicates that pepper fields contaminated with these weeds are under risk of viral infections. http://www.phytoparasitica.org posting July 21, 2005.     

新疆番茄病毒病检测及南方番茄病毒全基因组序列测定与传播特性分析

为了解新疆番茄上病毒病的发生情况,利用一步法RT-PCR技术检测了南北疆番茄上南方番茄病毒(Southern tomato virus,STV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、番茄花叶病毒(Tomato mosaic virus,ToMV)以及马铃薯Y病毒(Potato virus Y,PVY)的感染情况,并利用分段克隆的方法进行全基因组测序,通过RT-PCR方法检测健康植株与携带病毒植株杂交育种的F1代植株带毒率以分析STV的种子传播特性。结果显示,新疆番茄上CMV、STV、ToMV和PVY在北疆的检出率分别为52%、37%、27%和14%;在南疆的检出率分别为79%、60%、69%和0;且以STV、CMV及ToMV的复合侵染为主。从我国加工番茄上首次获得了长3 437 nt的STV SHZ-1核苷酸序列,序列比对分析发现其与已报道STV只有1~9个核苷酸的变异,且序列变异与地域无相关性。分析杂交F1代加工番茄植株上STV的传播特性,发现其除可由种子传播外,也可通过花粉传播。表明STV是侵染新疆番茄的主要病毒之一,且该病毒可通过种子或杂交育种途径进行传播。     

A study of viral coat protein accumulation in lily chloroplasts from mixed virus infections of Lily mottle virus and Cucumber mosaic virus

Two viruses that frequently occur in many Lilium species are Lily mottle virus (LMoV) and Cucumber mosaic virus (CMV), which usually co-infect lilies causing severe disease symptoms. Recent reports have revealed that the viral coat protein (CP) affects chloroplast ultrastructure and symptom development. This study used western blot analysis to confirm that in leaves infected by mixed virus infections of LMoV and CMV, CPs of both viruses were accumulated in lily chloroplasts. Immunogold labelling further demonstrated that both the LMoV CP and CMV CP were localized in the stroma and the thylakoid membranes of the chloroplasts. In addition, it was found that CPs of both viruses were rapidly transported into isolated, intact chloroplasts (in vitro), and their transport efficiencies were positively related to CP concentrations. The lowest transmembrane concentration of CMV CP decreased from 38 μg mL⁻¹ recorded in the single CMV CP import system to 10 μg mL⁻¹ in the mixed import system of LMoV CP and CMV CP. CPs of both viruses exhibited species selection in their transmembrane transport into chloroplasts. This is the first report that the CPs from two viruses (LMoV and CMV) are simultaneously present in lily chloroplasts. Accumulation of high levels of LMoV CP and CMV CP inside the chloroplast appears to contribute to a synergistic interaction inducing the development of mosaic symptoms.     

Viruses affecting tomato crops in Serbia

In a two-year survey (2011–2012), 3220 samples were collected and analyzed in order to determine the presence and distribution of viruses in tomato crops at 56 localities of 18 districts in Serbia. Out of 12 viruses tested, Cucumber mosaic virus (CMV), Potato virus Y (PVY), Alfalfa mosaic virus (AMV), Tomato spotted wilt virus (TSWV), Tomato mosaic virus (ToMV) and Tobacco mosaic virus (TMV) were detected in 42.1, 40, 11, 8.6, 2.3 and 1.3% of the total tested samples, respectively. The results revealed that CMV was prevalent in 2011 and PVY in 2012. CMV and PVY, apart from being predominant, were also the most widespread viruses. In general, single infections were the most frequent type of infection. Additionally, the most common mixed infections were double infections and the most prevalent combination was CMV and PVY. In 2011, the incidence of diseases and the percentage of all infection types were significantly higher than in 2012. Furthermore, in 2011, regardless of total single infections being prevalent compared to mixed infections, two prevailing viruses were commonly detected in mixed infections. The additional molecular testing of ELISA-negative samples using virus specific primers did not reveal the presence of Pepino mosaic virus (PepMV), Tomato yellow leaf curl virus (TYLC), Tomato infections chlorosis virus (TICV) and Tomato chlorosis virus (ToCV).     

<Emphasis Type="Italic">Cucumber mosaic virus</Emphasis> isolated from Amazon lily (<Emphasis Type="Italic">Eucharis grandiflora</Emphasis>)

Cucumber mosaic virus (CMV) was isolated from a mosaic diseased plant of Eucharis grandiflora. The virus caused mosaic symptoms on leaves and slight distortion of flower petals in E. grandiflora by either mechanical or aphid inoculation. The virus was identified as a strain of CMV subgroup I from its biological and serological characteristics.     

Characterization of Grapevine Algerian latent virus isolated from nipplefruit (Solanum mammosum) in Japan

Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV), Potato virus Y (PVY), Tomato bushy stunt virus nipplefruit strain (TBSV-Nf), and an unknown spherical virus were isolated from nipplefruit (Solanum mammosum) cultivated in Chiba Prefecture, Japan. The spherical virus was identified as Grapevine Algerian latent virus nipplefruit strain (GALV-Nf) from the genus Tombusvirus, based on its physical properties, serological relationships, and analysis of genomic RNA. The genomic RNA of GALV-Nf is 4731 nucleotides long and encodes five open reading frames as well as those of other tombusviruses. Nipplefruit infected with GALV-Nf had severe stunting, leaf deformation, and clear mosaic symptoms. This is the first report of an isolation of GALV in Japan. An erratum to this article is available at .     

High incidence of <Emphasis Type="Italic">Pelargonium line pattern virus</Emphasis> infecting asymptomatic <Emphasis Type="Italic">Pelargonium</Emphasis> spp. in Spain

Geraniums (Pelargonium spp.) are traditional ornamental plants largely cultivated in Europe and northern America. Vegetative propagation makes them prone to viral infections, which have detrimental effects on crop production and quality. Asymptomatic samples collected in Spain were tested for a range of viruses using ELISA. The tobamovirus, Tobacco mosaic virus (TMV), the cucumovirus, Cucumber mosaic virus (CMV), and several viruses in the family Tombusviridae, namely, Pelargonium line pattern virus (PLPV), Pelargonium flower break virus (PFBV), and Pelargonium leaf curl virus (PLCV), were detected either singly or in combination in 59.2% of 800 samples. PLPV and PFBV infections were confirmed by dot-blot hybridisation. The most relevant viral infection found on Spanish asymptomatic geraniums was by Pelargonium line pattern virus (PLPV). Symptoms did not develop for 3 years on most of the PLPV infected geranium plants under greenhouse conditions.     

Molecular epidemiology of cassava mosaic disease in Madagascar

Cassava is the staple food for hundreds of millions of people in Africa but its cultivation is seriously constrained by cassava mosaic disease (CMD) in Madagascar, and in Africa in general. This study identified the cassava mosaic geminiviruses (CMGs) involved in CMD in Madagascar and their associated epidemiological characteristics from countrywide surveys. Molecular characterization of CMGs in Madagascar revealed an unprecedented diversity and co‐occurrence of six viruses: African cassava mosaic virus (ACMV), East African cassava mosaic Cameroon virus (EACMCV), East African cassava mosaic Kenya virus (EACMKV), East African cassava mosaic virus (EACMV), South African cassava mosaic virus (SACMV) and the recently described Cassava mosaic Madagascar virus (CMMGV). Distinct geographical distributions were observed for the six viruses. While ACMV was more prevalent in the central highlands, EACMV and EACMKV were prevalent in lowlands and coastal regions. Both EACMCV and SACMV occurred in almost all the localities visited. PCR diagnosis revealed that mixed infection (up to four co‐infected viruses) occurred in 21% of the samples and were associated with higher symptom severity scores. Pairwise comparisons of virus associations showed that EACMCV was found in mixed infections more often than expected while ACMV and SACMV were mostly found in single infections. A greater abundance of whiteflies was observed in lowland and coastal areas. Nevertheless, infected cuttings remain the primary source of CMD propagation (95%) in Madagascar.     

Viruses of vegetable crops in Albania

Field surveys were carried out in the main vegetable-growing areas of Western and Central Albania to evaluate the sanitary status of open-field and protected cultivations of capsicum, tomato, potato, watermelon, cucumber, courgette, aubergine, lettuce, cabbage, chicory, leek and celery. The following viruses were detected: Alfalfa mosaic alfamovirus (AMV), Cucumber mosaic cucumovirus (CMV), Potato Y potyvirus (PVY), Tomato spotted wilt tospovirus (TSWV) and Watermelon mosaic potyvirus 2 (WMV-2). The virus found most frequently was CMV and all the isolates identified were of subgroup IA. AMV was also detected in several areas and all isolates were of subgroup II, suggesting a French origin. Finally, at the time of this survey, TSWV infections appeared to be moderately relevant and absent in protected crops. This is the first documented record of AMV, CMV, PVY, TSWV and WMV-2 in Albania. No infection by Tomato yellow leaf curl begomovirus (TYLCV) or Zucchini yellow mosaic potyvirus (ZYMV) was detected during this survey.     

Occurrence and distribution of viruses infecting tomato and pepper in Alibori in northern Benin

In surveys conducted in 2011 and 2012 to identify the viruses causing diseases on pepper and tomato in the department of Alibori in northern Benin, 451 samples of pepper and tomato were analyzed by ELISA using 11 specific antibodies. The highest virus incidence among the surveyed districts was recorded on pepper in Malanville (56.18%), followed by Karimama (39.32%). The most frequently found viruses were Pepper veinal mottle virus (PVMV), Cucumber mosaic virus (CMV), and Potato virus Y-necrotic (PVY-n), accounting respectively for 22.39%, 21.73% and 15.96% of the collected samples. Tomato yellow leaf curl virus (TYLCV) was detected in only 2.43% of the samples, whereas Alfalfa mosaic virus (AMV), Chilli veinal mottle virus (ChiVMV), Tomato mosaic virus (ToMV) and Tomato spotted wilt virus (TSWV) were not detected in any of the samples tested. Double and triple infections involving different virus combinations were found, respectively, in 14.86% and 4% of the samples. Five plant species (Euphorbia hirta Linnaeus, Moringa oleifera Lam, Leucas martinicencis (Jacquin) R. Brown, Combretum micranthum G. Don, Abelmoschus esculentus L. Moench.) out of 30 samples belonging to 13 botanical families, collected within or nearby tomato and pepper fields, were found infected with PVMV, PVY-n, and CMV. Control measures to reduce the impact of viruses on pepper and tomato production are discussed. This is the first report of viruses infecting pepper and tomato in Benin.     

2b Protein is essential to induce a novel gradual cell death in Zucchini yellow mosaic virus-inoculated cucumber cotyledon co-infected with Cucumber mosaic virus

Cucumber cotyledons inoculated with Cucumber mosaic virus (CMV, Pepo strain) or Zucchini yellow mosaic virus (ZYMV, Z5-1 isolate) developed either mild chlorotic spots or no symptoms. Cotyledons treated with CMV plus ZYMV also developed mild chlorotic spots. However, plants ZYMV-inoculated cotyledons had veinal yellowing and gradual cell death by 20 days postinoculation (dpi) when co-inoculated with CMV on the other cotyledon. When analyzing this synergism, an enzyme-linked immunosorbent assay showed that CMV gradually increased in CMV-inoculated cotyledons of plants, with the other cotyledon mock- or ZYMV-inoculated. However, CMV significantly increased at 9 to 14 dpi in the ZYMV-inoculated cotyledons of plants co-infected with CMV. ZYMV similarly increased in cotyledon pairs of both co-infected and singly infected plants. Inoculation with PepoΔ2b, a modified Pepo-CMV that lacks translation of the 2b protein, revealed that PepoΔ2b without the 2b protein systemically infected cucumber but induced no symptoms on cotyledons or true leaves. Plants with a ZYMV-inoculated cotyledon and co-infected with PepoΔ2b did not undergo cell death; nevertheless, PepoΔ2b was at high levels comparable to levels of CMV in the ZYMV-inoculated cotyledon. The 2b protein thus seems essential for induction of the novel gradual cell death in ZYMV-inoculated cotyledons of cucumbers co-infected with CMV.