Viruses are a major cause of loss in many australian vegetable crops. Big vein disease bv of lettuce has been attributed to infection by lettuce big vein virus lbvv, vectored by the soil fungus olpidium brassicae. Two viruses are associated with lbvd, lettuce bigvein associated virus lbvav, varicosavirus and mirafiori lettuce bigvein virus milbvv, ophiovirus which are transmitted by the soil fungus olpidium brassicae verbeek et al. Big vein is an economically damaging disease of lettuce lactuca sativa caused by the olpidium brassicae vectored mirafiori lettuce big vein virus mlbvv. The finding of a second soilborne virus in lettuce, mirafiori lettuce virus milv, led to a reinvestigation of the role of lbvv in big vein disease, with evidence emerging that both milv and lbvv are vectored by o. Available resistance can be described as resistance against big vein disease rather than against lettuce big vein virus.
Genetic variation of populations of citrus psorosis virus. During the cooler season may to september, two viruses have been found associated with big vein disease, mirafiori lettuce big vein virus mlbvv which belongs to the genus ophiovirus and lettuce big vein associated virus lbvav. Two viruses are associated with lbvd, lettuce big vein associated virus lbvav, varicosavirus and mirafiori lettuce big vein virus milbvv, ophiovirus which are transmitted by the soil fungus olpidium brassicae verbeek et al. Common name isynonym iother names i mirafiore lettuce big vein virus mirafiore lettuce virus mirafiori lettuce big vein virus mirafiori lettuce virus. The occurrence of big vein disease symptoms and the association of lettuce bigvein associated virus lbvav and mirafiori lettuce bigvein virus mlbvv was evaluated by rtpcr using specific. Transmission by olpidium brassicae of mirafiori lettuce. Occurrence and partial characterization of lettuce big. Lettuce mosaic virus is just that a virus that is seed borne in all types of lettuce except endive. May 01, 2010 the complete coat protein cp nucleotide sequences of seven lettuce big vein associated virus lbvav isolates from australia were compared to those of 22 other lbvav and five tobacco stunt virus tstv isolates. We used illumina small rna sequencing srnaseq to identify. The causal agent is mirafiori lettuce big vein virus mlbvv, an ophiovirus transmitted by the soilborne fungus olpidium brassicae lot et al. Big vein is an economically damaging disease of lettuce lactuca sativa caused by the olpidium brassicaevectored mirafiori lettuce bigvein virus mlbvv.
The complete coat protein cp nucleotide sequences of seven lettuce big vein associated virus lbvav isolates from australia were compared to those of 22 other lbvav and five tobacco stunt virus tstv isolates. In regions with heavy and humid soils, lettuce mirafiori big vein virus lmbvv can also produce major yield losses. Even though the virus is soilborne and therefore always present in infested fields, disease severity may vary greatly from season to season. Good agricultural practices for greenhouse vegetable. General information about mirafiori lettuce big vein virus milbvv eppo global database. Iris yellow spot virus lbvv lettuce bigvein virus lca life cycle analysis ldpe low density polyethylene ler land equivalency ratio lysv leek yellow stripe virus mad management allowable depletion milbbv mirafiori lettuce bigvein virus nft nutrient film technique nir nearinfrared radiation nt night temperature oecd. Abstract big vein disease occurs on lettuce worldwide in temperate conditions. Big vein is more prevalent and severe during cool spring weather. The reported variation in the reaction of wild lactuca species to pathogens and pests is summarized, including viral pathogens e. Big vein is an economically damaging disease of lettuce lactuca sativa caused by the olpidium brassicae vectored mirafiori lettuce bigvein virus mlbvv. Molecular genetic characterisation of mirafiori lettuce big.
Lettuce big vein associated virus lbvav is a pathogenic plant virus. It is certain, however, that this viral disease is transmitted by an oomycete, olpidium virulentus. Mlbvv has been detected in many different areas of the world but never in argentina. Maisonneuve high level resistance to mirafiori lettuce bigvein virus, the causal agent of big vein disease, is known in l. Bigvein disease bv of lettuce has been attributed to infection by lettuce bigvein virus lbvv, vectored by the soil fungus olpidium brassicae. The virus that causes big vein is soilborne and is introduced into lettuce plants by a soil fungus olpidium brassicae that attaches itself to lettuce roots. Lettuce big vein virus lbvv is a plant pathogenic virus. Mar 16, 2017 navarro ja, botella f, maruhenda a, sastre p, sanchezpina ma, pallas v 2005 identification and partial characterisation of lettuce bigvein associated virus and mirafiori lettuce bigvein virus in common weeds found amongst spanish lettuce crops and their role in lettuce bigvein disease transmission. This is a taxonomic list of all viruses as of 2018 listed by the international committee on taxonomy of viruses. Host resistance to mirafiori lettuce bigvein virus and lettuce bigvein associated virus and virus sequence diversity and frequency in california.
Family groupsthe baltimore method this plant virus article. Green peach aphids can spread the virus as they move about a lettuce field, sipping plant juices. Genetic variation for bigvein symptom expression and resistance to mirafiori lettuce bigvein virus in lactuca virosa l. Though not used by the ictv, the traditional baltimore classification, which groups viruses together based on how they produce mrna, is used in conjunction with the ictvs work in modern virus classification. It is the result of infected seeds, although weed hosts are carriers, and the disease can be vectored by aphids, which spread the virus throughout the crop and into nearby flora. Host resistance to mirafiori lettuce big vein virus and lettuce big vein associated virus and virus sequence diversity and frequency in california. Approach from ad416 use serological and molecular methods to analyze virus concentration in lettuce breeding lines. Furthermore, since the lettuce infected with this virus alone developed big vein symptoms, it is considered to be a main agent of the big vein disease. Lettuce big vein virus info treating big vein virus of. Tomato spotted wilt virus tswv is another virus that causes severe damage since the introduction of its major vector, the thrips frankliniella occidentalis. Host resistance to mirafiori lettuce bigvein virus and. The phylogenetic relationships of lettuce bigvein associated virus lbvav and mirafiori lettuce bigvein virus mlbvv and their vector olpidium virulentus, associated with lbvd in western australia were established. Resistance of wild lactuca genetic resources to diseases.
Moshe elbaz head of insect biology agplenus linkedin. We continued crosses to develop bc families from salinas x sal012. Abstract bigvein disease occurs on lettuce worldwide in temperate conditions. Lettuce mosaic, caused by a virus of the same name, results in stunting and unattractive mottling. Comparison of the coat protein genes of lettuce big vein. Virus diseases of lettuce in brazil global science books.
Several studies have associated this disease with mirafiori lettuce big vein virus milbvv alone or in mixed infection with lettuce big vein associated virus lbvav. These symptoms resemble those caused by lettuce big vein disease lbvd, an important disease of lettuce worldwide. Transmission by olpidium brassicae of mirafiori lettuce virus and lettuce bigvein virus, and their roles in lettuce bigvein etiology. Olpidium has two important functions in the etiology of the disease 5. The objectives of this research were to determine the genetic variation for bigvein symptom expression and. Resistance of wild lactuca genetic resources to diseases and. Lettuce bigvein disease bvd affects all major lettuceproducing areas of the world. Detection of varicosavirus and ophiovirus in lettuce associated with lettuce bigvein symptoms in brazil. During 2014 and 2015, 97 lettuce plants that showed bigveindiseaselike symptoms and seven weed plants were collected from the riyadh region.
Lbvv is defined as lettuce bigvein virus somewhat frequently. Viruses in vegetable crops in australia integrated virus disease management. Progress 111804 to 107 outputs progress report objectives from ad416 determine concentration of mirafiori lettuce big vein virus on lettuce breeding lines to develop varieties with high levels of resistance to big vein disease of lettuce. The emerging lettuce bigvein disease lbvd is causing losses in lettuce production ranging from 30 to 70% worldwide. Read citrus psorosis and mirafiori lettuce bigvein ophiovirus coat proteins localize to the cytoplasm and self interact in vivo, virus research on deepdyve, the largest online rental service for scholarly research with thousands. Mirafiori lettuce bigvein virus milbvvoverview eppo. We used illumina small rna sequencing srnaseq to identify viruses present in symptomatic lettuce plants. Daselisa revealed that 25% and 9% of the lettuce plants were singly infected with lbvav and milbvv, respectively, whereas 63% had a mixed infection with both viruses. Lettuce big vein agent lbva is probably caused by a virus, although the virus particle has not been seen with the electron microscope. On phylogenetic analysis, clade i contained only lbvav isolates from europe, subclade iia only australian lbvav isolates, iib only japanese lbvav.
New dna equipment reveals risk of socalled symptomfree. Genetic variation for bigvein symptom expression and. Analysis of part of the coat protein cp gene of iranian isolates of lbvav showed 97. It is certain, however, that this viral disease is transmitted by an oomycete, olpidium virulentus, previously known as o. Citrus psorosis virus cpsv, the type species of genus ophiovirus, has a segmented, negativestranded rna genome. This causal agent may be a virus but has not been characterized 12,20. Approach from ad416 use serological and molecular methods to analyze virus concentration in.
The virus is not transmissible by inoculation of sap but has been transmitted by whitefly inoculation to plants in at least 45 species and 15 families duffus et al. Transmission by olpidium brassicae of mirafiori lettuce virus. Pdf further evidence of mirafiori lettuce bigvein virus. Occurrence and partial characterization of lettuce big vein. Most isolates contained a predominant sequence and some minor. Lettuce mosaic virus an overview sciencedirect topics. Molecular analysis and virus transmission tests place olpidium virulentus, a vector of mirafiori lettuce bigvein virus and tobacco stunt virus, as a distinct species rather than a strain of olpidium brassicae. Although big vein is a perennial problem in the us, the extent of mlbvv infection and diversity was unknown. Bos and huijberts 1990 described several lettuce cultivars that display delayed attack or long incubation periods. They also describe an absence of disease in lactuca virosa.
What major problem or issue is being resolved and how are you. Lettuce bigvein associated virus lbvav is a pathogenic plant virus. Most liyvinfected plants, including lettuce, cucurbits and chenopodium spp. However, in 2000, a second virus, mirafiori lettuce virus, was found in lettuce showing big vein symptoms. Molecular genetic characterisation of mirafiori lettuce. Abstract california lettuce research board for the. Genetic variation for big vein symptom expression and resistance to mirafiori lettuce big vein virus in lactuca virosa l. Mirafiori lettuce bigvein virus isolate ls301o nucleocapsid gene, complete cds. Lettuce cultivars partially resistant to big vein reduce. Mirafiori lettuce bigvein virus and lettuce bigvein associated virus and virus sequence diversity and frequency in california. Taxonomy navigation mirafiori lettuce big vein ophiovirus. Lbvav and mlbvv are both transmitted by the soilborne fungus olpidium. Lettuce mosaic virus ndash lmv, mirafiori lettuce virus lettuce big vein virus ndash lbvv, cucumber mosaic virus ndash cmv, bacterial pathogens corky root ndash rhizomonas suberifaciens, bacterial leaf spot. The objectives of this research were to determine the genetic variation for big vein symptom expression and.
The causal agent is mirafiori lettuce bigvein virus mlbvv, an ophiovirus transmitted by the soilborne fungus olpidium brassicae lot et al. This disease differs greatly from the other lettuce virus diseases. Dec 01, 2012 read citrus psorosis and mirafiori lettuce big vein ophiovirus coat proteins localize to the cytoplasm and self interact in vivo, virus research on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. In the different positions i occupied, i established biological screening platforms designated for discovery of insecticidal activity in microbial organisms, small molecule, proteinaceous insecticides and plant resistance traits. A multigene phylogeny of olpidium and its implications for. Identification of mirafiori lettuce bigvein virus and. I am an entomologist in profession phd, highly experienced in insect ecology and molecular biology research lead. Lettuce big vein associated virus lbvav is also frequently identified in symptomatic plants, but no causative relationship has been demonstrated. Abstract california lettuce research board for the period. The phylogenetic relationships of lettuce big vein associated virus lbvav and mirafiori lettuce big vein virus mlbvv and their vector olpidium virulentus, associated with lbvd in western australia were established. Detection of varicosavirus and ophiovirus in lettuce.
Though not used by the ictv, the traditional baltimore classification, which groups viruses together based on how they produce mrna, is used in conjunction with the ictvs work in modern virus classification note that ictv assesses other noncellular life besides. Progress 100106 to 093007 outputs progress report objectives from ad416 determine concentration of mirafiori lettuce big vein virus on lettuce breeding lines to develop varieties with high levels of resistance to big vein disease of lettuce. Several studies have associated this disease with mirafiori lettuce bigvein virus milbvv alone or in mixed infection with lettuce bigvein associated virus lbvav. Small rnaseq to characterize viruses responsible of. New dna equipment reveals risk of socalled symptomfree lettuce big vein associated virus. Lbvv is defined as lettuce big vein virus somewhat frequently. In regions with heavy and humid soils, lettuce mirafiori bigvein virus lmbvv can also produce major yield losses. Occurrence of mirafiori lettuce virus and lettuce bigvein. Both mirafiori lettuce big vein virus mlbvv and lettuce big vein associate virus lbvav are associated with big vein infected lettuce plants, but only mlbvv has been identified as a causal agent. Mirafiori lettuce big vein virus milbvv and lettuce big vein associated virus lbvav were found in association with big vein disease of lettuce in iran. The occurrence of big vein disease symptoms and the association of lettuce big vein associated virus lbvav and mirafiori lettuce big vein virus mlbvv was evaluated by rtpcr using specific. Mirafiori lettuce big vein virus, which makes its way to lettuce roots via a soildwelling, funguslike microbe.
The zoospores carry the bva, apparently internally, and inoculate it. During the cooler season may to september, two viruses have been found associated with bigvein disease, mirafiori lettuce bigvein virus mlbvv which belongs to the genus ophiovirus and lettuce bigvein associated virus lbvav. Big vein bv is an economically damaging disease of lettuce lactuca sativa l. Superior lettuces fend off two destructive viruses. We examined the population structure and genetic variation of cpsv in three coding regions located in rnas 1, 2 and 3, analysing 22 isolates from argentina, california, florida, italy and spain.
The virus is the cause of lettuce big vein disease references. Jun 22, 2012 new dna equipment reveals risk of socalled symptomfree lettuce big vein associated virus. Biological and serological dasenzyme linked immunosorbent assay elisa tests together with electron microscope observations, revealed the presence of lettuce big vein virus and mirafiori lettuce virus, in these plants both responsible for the lettuce big vein syndrome. Af525936 mirafiori lettuce bigvein virus isolate ls301o 10.
First reports of lettuce bigvein associated virus and. Transmission by olpidium brassicae of mirafiori lettuce virus and lettuce big vein virus, and their roles in lettuce big vein etiology. Small rnaseq to characterize viruses responsible of lettuce. The finding of a second soilborne virus in lettuce, mirafiori lettuce virus milv, led to a reinvestigation of the role of lbvv in bigvein disease, with evidence emerging that both milv and lbvv are vectored by o.