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Pox Virus (pox + virus)
Kinds of Pox Virus Selected AbstractsHypersensitivity of Plum Genotypes to Plum Pox VirusJOURNAL OF PHYTOPATHOLOGY, Issue 3-4 2001Kegler The hypersensitive response (HR) of plum hybrid K4 as an active defence mechanism is directed against certain plum pox virus (PPV) strains/isolates of the type CG but not against type DI. There is no clear correlation between the HR of K4 and serological differences of the PPV strains D, M and C, respectively. A total of 14 genotypes out of 21 progenies of K4 reacted necrotically and were proved to be either hypersensitive and field resistant or highly sensitive and not field resistant. The HR can be connected with a complete or with an incomplete virus localization in K4 and some of its progenies. The remaining genotypes were more or less sensitive and tolerant, respectively. Growth of buds from PPV-CG-infected plum cultivars on K4 differed in the degree of systemic virus invasion in the plant as a trait of quantitative virus resistance. The percentage of growing buds correlated with the level of quantitative PPV resistance. [source] Plum pox virus and the estimated costs associated with sharka diseaseEPPO BULLETIN, Issue 2 2006M. Cambra Since first being recorded in 1917,18 in Bulgaria, sharka (plum pox) disease has progressively spread via infected plant material to be present in most Prunus -growing nations today. The disease has serious agronomic and political consequences because it causes enormous economic losses. In countries in which sharka is endemic, a high percentage of apricot and European plum production is unmarketable because of the disease. To these figures should be added the costs of sanitary controls, surveys and eradication programmes against sharka virus. Estimated costs associated with sharka management worldwide in the last 30 years exceed 10 000 million euros. However, improvements in knowledge of the disease and in techniques used to identify the disease are significantly aiding disease control and management. [source] Plum pox virus (PPV) in FranceEPPO BULLETIN, Issue 2 2006Pierre Speich No abstract is available for this article. [source] Plum pox virus (PPV) in GermanyEPPO BULLETIN, Issue 2 2006W. Jarausch No abstract is available for this article. [source] Plum pox virus (PPV) in PolandEPPO BULLETIN, Issue 2 2006T. Malinowski No abstract is available for this article. [source] Plum pox virus (PPV) in RomaniaEPPO BULLETIN, Issue 2 2006M. Isac No abstract is available for this article. [source] Plum pox virus (PPV) in RussiaEPPO BULLETIN, Issue 2 2006Y. Prichodko No abstract is available for this article. [source] Hosts and symptoms of Plum pox virus: fruiting Prunus speciesEPPO BULLETIN, Issue 2 2006G. Llácer A description of plum pox (sharka) symptoms on European and Japanese plum, apricot, peach, sweet and sour cherry and almond is presented. Plum pox is a serious disease mainly because it produces severe symptoms on fruits of numerous cultivars of Prunus species, causing fruit to fall or making them unfit for consumption. [source] Epidemiology of sharka disease in FranceEPPO BULLETIN, Issue 2 2006G. Labonne Plum pox virus was first detected in France in the 1960s. Both PPV-D and PPV-M strains are present but epidemics related to the PPV-M strain detected in the late 1980s are the most problematic. The two PPV strains have unequal distributions in peach and apricot orchards and different prevalences. More than 20 different aphid species have been identified as vectors of PPV but most of them do not colonize Prunus species. Thus, aphids involved in the spread of PPV in orchards are essentially visiting aphids. The main sources of inoculum for the vectors are leaves and fruits of infected stone-fruit trees. Spontaneous, wild and ornamental Prunus species such as Prunus dulcis, P. spinosa or P. pissardii are susceptible to PPV isolates found in France but their role as a reservoir in sharka epidemics is probably negligible. The disease spreads rapidly in orchards but the rate of progression may vary according to the identity of the PPV strain and the Prunus species. Analysis of spatial patterns of disease has shown that secondary spread by aphids frequently occurs over short distances in the orchards (aggregated patterns) but also that dissemination at longer distances (of several hundred metres) is a common event. [source] Epidemiology of Plum pox virus strain M in GreeceEPPO BULLETIN, Issue 2 2006C. Varveri Plum pox virus has been endemic in Greece since 1967 causing important losses in apricot and to a lesser extent in peach crops. A survey undertaken in 1992 in public and private mother-tree plantations to estimate its incidence revealed that the virus was absent in isolated areas far from commercial stone-fruit crops. Virus titers decrease significantly during the hot months in the infected trees but re-increase in October,November permitting reliable detection. It is virulent M-type isolates which are effectively transmitted by aphids that are mostly recovered. Aphis gossypii and Hyalopterus pruni were the most abundant virus vectors captured during the small scale monitoring undertaken in apricot orchards in 1999 and 2000. Virus spread was monitored in two apricot orchards from 1996 to 2000 and analysed. Initial infections followed a completely random spatial pattern, while loose clusters appeared in succeeding years, to finally reach a uniform distribution representing high infection levels. The nearby ecological conditions greatly affected the rate of disease development. [source] Control and monitoring: control of Plum pox virus in the United KingdomEPPO BULLETIN, Issue 2 2006R. A. Mumford Plum pox virus (PPV) was first identified in the United Kingdom in 1965. Despite a rigorous eradication policy, the disease spread quickly and established itself in all the main plum-growing areas in England. In 1975, the policy was changed from a blanket eradication campaign to one of containment; retaining statutory control of PPV on propagation material but allowing the industry to control the disease in orchards. As part of the current containment campaign, annual surveys are carried out on propagation material. These surveys show that the incidence of PPV in this material is very low and that only the D-strain is present. The precise situation regarding PPV incidence in commercial orchards is unknown. Given the low incidence in propagation material, it is likely that PPV is uncommon in actively managed orchards. However, some infected orchards probably do still exist, especially older, unmanaged or abandoned ones. Overall, the history of PPV control in the UK is one of unsuccessful eradication but successful containment. The UK experience demonstrates that given the right combination of strain and host, alongside a regular testing regime, it is possible to control PPV through the establishment of a regulated certification scheme and the supply of virus-free planting material. [source] Breeding for resistance: conventional breeding for Plum pox virus resistant apricots (Prunus armeniaca L.) in GreeceEPPO BULLETIN, Issue 2 2006I. Karayiannis A large apricot breeding programme has been conducted at NAGREF-Pomology Institute, Naoussa-Greece, for the control of sharka disease, since 1989. Ten apricot cultivars of North American origin: ,Stark Early Orange', ,Stella', ,NJA2', ,Sunglo', ,Veecot', ,Harlayne', ,Henderson', ,Goldrich', ,Orangered' and ,Early Blush', selected for their resistance to the highly virulent local strain of Plum pox virus (PPV)-M (Marcus), have been used as parents in crosses with quality cultivars, mainly with the local cv. Bebecou, from 1989 to 2003. Approximately 7000 hybrids have been created. Resistance to PPV was the main criterion of selection. Most hybrids have been subjected to artificial inoculation by PPV-M and examined for symptom expression for more than five years. Indexing to GF-305, as well as laboratory diagnostic tests, have been applied. The genetic analysis showed that: (1) 50% of the hybrids inherited resistance to PPV in the families where cvs. Stark Early Orange, NJA2, Sunglo, Veecot and Harlayne were used as a parent, and (2) 100% of the hybrids inherited resistance to PPV in the families where cv. Stella was one of the parents. Resistance to PPV appears to be under simple genetic control involving one gene locus. Promising apricot selections resistant to PPV-M have been released. [source] Prevalence of avian pox virus and effect on the fledging success of Laysan AlbatrossJOURNAL OF FIELD ORNITHOLOGY, Issue 1 2008Lindsay C. Young ABSTRACT Avian pox virus (Poxvirus avium) is a mosquito-borne disease that occurs worldwide in a variety of bird species, but little is known about its prevalence or effect on seabirds. We monitored prevalence of pox virus and its effect on fledging success of Laysan Albatross (Phoebastria immutabilis) on Oahu, Hawaii, from 2003 to 2007. Pox prevalence in albatross chicks averaged 88% in years with high rainfall and 3% in years with low rainfall. Diagnosis of pox virus was clinically confirmed in two birds by Muscovy Duck (Cairina moschata) fibrolast cultures. Severity of infection ranged from small wart-like nodules and lesions on the bill, face, eyes, tarsus, and feet, to large tumorous growths that completely covered both eyes and caused deformation of the bill and skull. Most chicks recovered from infection, and the fledging rate in pox epizootic years (82%) did not differ from that in years with low pox prevalence (80%) or the average fledging rate on Midway Atoll (86%). Three chicks with severe infections were resighted as healthy adults on Kauai and Oahu in 2007, confirming postfledging survival of at least some birds. The high recovery rate, fledging success, and postfledging survival indicate that Laysan Albatross have strong immunity to avian pox virus. SINOPSIS La viruela aviar (Poxvirus avium) es una enfermedad que afecta muchas especies de aves a nivel mundial. La enfermedad es transmitida por mosquitos y se sabe poco de su prevalencia y efecto en aves acuáticas. Monitoreamos la prevalencia de este virus y su efecto en volantones de albatros (Phoebastria immutabilis) en Oahu, Hawaii, en trabajo que se llevo a cabo desde el 2003,2007. Encontramos una prevalencia de 88% en pichones de albatros en años lluviosos y de 3% en años de poca lluvia. Se diagnosticó el virus, clínicamente, en dos patos comunes (Cairina moschata) mediante la técnica de cultivo fibroblástico. La severidad de la infección varió desde leve con algunas lesiones en el pico, cara, ojos, tarso y patas, hasta casos severos con grandes tumores que cubrían los ojos y causaron malformación de pico y craneo. La mayoría de los pichones se recobraron de la infección. La tasa de pichones que dejaron el nido (82%) en años de alta incidencia (82%) fue similar (80%) a los años de pocas infecciones y al promedio de volantones (86%) en el Atolón de Midway. Tres individuos observados como pichones con infecciones severas fueron avistados posteriormente como adultos saludables en Kauai y Oahu en el 2007, lo que confirma la sobrevivencia post-volanton de al menos algunas aves. La tasa tan alta de recobro, éxito en dejar el nido y sobrevivencia post-volantón indican que en el Albatros de Laysan hay una alta inmunidad hacia la viruela aviar. [source] Hypersensitivity of Plum Genotypes to Plum Pox VirusJOURNAL OF PHYTOPATHOLOGY, Issue 3-4 2001Kegler The hypersensitive response (HR) of plum hybrid K4 as an active defence mechanism is directed against certain plum pox virus (PPV) strains/isolates of the type CG but not against type DI. There is no clear correlation between the HR of K4 and serological differences of the PPV strains D, M and C, respectively. A total of 14 genotypes out of 21 progenies of K4 reacted necrotically and were proved to be either hypersensitive and field resistant or highly sensitive and not field resistant. The HR can be connected with a complete or with an incomplete virus localization in K4 and some of its progenies. The remaining genotypes were more or less sensitive and tolerant, respectively. Growth of buds from PPV-CG-infected plum cultivars on K4 differed in the degree of systemic virus invasion in the plant as a trait of quantitative virus resistance. The percentage of growing buds correlated with the level of quantitative PPV resistance. [source] Quantitative resistance to Plum pox virus in Prunus davidiana P1908 linked to components of the eukaryotic translation initiation complexPLANT PATHOLOGY, Issue 3 2009G. Marandel A complex, polygenic resistance to Plum pox virus (PPV) was previously described in a wild peach-related species, Prunus davidiana clone P1908. In the current study, an analysis of quantitative trait loci (QTL) was performed on an F2 population comprising 99 individuals obtained by selfing the F1 individual #40 of an interspecific cross between susceptible nectarine cv. Summergrand and the resistant P. davidiana clone P1908. Six QTL were identified using both parametric and non-parametric methods of detection, individually explaining 5,28% of the phenotypic variance. The total phenotypic variation explained ranged from 29 to 58%. Alignment of the genetic map of the F2 cross with the P. davidiana parent map showed consistency of QTL over generations, with three of the six QTL co-localizing at the 1-LOD interval and another one at the 2-LOD interval. Two of the QTL were mapped onto linkage group one, where resistance to PPV was previously mapped in apricot. Development and mapping of new microsatellite markers linked to candidate genes revealed a striking co-localization of three of the detected QTL with gene copies coding for eukaryotic translation initiation factors eIF4E and eIF(iso)4G. As co-localization of one QTL with candidate gene eIF(iso)4E was previously reported in the F1 population, the results reported here strongly reinforce the idea that components of the eukaryotic translation initiation complex are correlated with resistance to PPV in P. davidiana P1908. [source] Cryotherapy of shoot tips: a technique for pathogen eradication to produce healthy planting materials and prepare healthy plant genetic resources for cryopreservationANNALS OF APPLIED BIOLOGY, Issue 3 2009Q.C. Wang Abstract Cryotherapy of shoot tips is a new method for pathogen eradication based on cryopreservation techniques. Cryopreservation refers to the storage of biological samples at ultra-low temperature, usually that of liquid nitrogen (,196°C), and is considered as an ideal means for long-term storage of plant germplasm. In cryotherapy, plant pathogens such as viruses, phytoplasmas and bacteria are eradicated from shoot tips by exposing them briefly to liquid nitrogen. Uneven distribution of viruses and obligate vasculature-limited microbes in shoot tips allows elimination of the infected cells by injuring them with the cryo-treatment and regeneration of healthy shoots from the surviving pathogen-free meristematic cells. Thermotherapy followed by cryotherapy of shoot tips can be used to enhance virus eradication. Cryotherapy of shoot tips is easy to implement. It allows treatment of large numbers of samples and results in a high frequency of pathogen-free regenerants. Difficulties related to excision and regeneration of small meristems are largely circumvented. To date, severe pathogens in banana (Musa spp.), Citrus spp., grapevine (Vitis vinifera), Prunus spp., raspberry (Rubus idaeus), potato (Solanum tuberosum) and sweet potato (Ipomoea batatas) have been eradicated using cryotherapy. These pathogens include nine viruses (banana streak virus, cucumber mosaic virus, grapevine virus A, plum pox virus, potato leaf roll virus, potato virus Y, raspberry bushy dwarf virus, sweet potato feathery mottle virus and sweet potato chlorotic stunt virus), sweet potato little leaf phytoplasma and Huanglongbing bacterium causing ,citrus greening'. Cryopreservation protocols have been developed for a wide variety of plant species, including agricultural and horticultural crops and ornamental plants, and can be used as such or adjusted for the purpose of cryotherapy. [source] | ||||||||||