Big vein is an economically damaging disease of lettuce lactuca sativa caused by the olpidium brassicaevectored mirafiori lettuce bigvein virus mlbvv. It has caused economically significant losses in new zealand, particularly in crops. We used illumina small rna sequencing srnaseq to identify viruses present in symptomatic lettuce plants. The emerging lettuce bigvein disease lbvd is causing losses in lettuce production ranging from 30 to 70% worldwide. Genetic variation for bigvein symptom expression and. 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. First reports of lettuce bigvein associated virus and. 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. Insecticidal sprays would presumably help to delay the spread of this particular virus disease. Viruses in vegetable crops in australia integrated virus disease management.
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. So far no lettuce cultivars have been identified that express a high level of resistance that does not vary as the severity of the disease. Symptoms vary according to type or variety of lettuce. Full text of diseases of lettuce see other formats i 1 division of agricultural sciences university of california california agricultural experiment station extension service circular 448. Botanical, mycological, zoological, and prokaryotic species names follow the linnaean format, consisting of an italicized latinized binomen with a capitalized genus name and a. Maisonneuve high level resistance to mirafiori lettuce bigvein virus, the causal agent of big vein disease, is known in l. Mirafiori lettuce virus milv and lettuce big vein virus lbvv sequence diversity and frequency in california and arizona lettuce, and analysis. Studies on lettuce big vein disease university of auckland. Page 4 of 9 the genus varicosavirus is recognized by the ictv, but has not yet been assigned to a family. New dna equipment reveals risk of socalled symptomfree lettuce big vein associated virus.
Two viruses are associated with lbvd, lettuce bigvein associated virus lbvav. Lettuce diseases and pests, description, uses, propagation. Lettuce growers usually plant in rotation, so that infected lands can be planted to another crop in spring and used for lettuce in warm conditions, when the disease will not occur. This causal agent may be a virus but has not been characterized 12,20. Possibility and challenges of conversion of current virus. Lettuce bigvein disease lbvd is a common chytrid and soilborne virus disease that affects lettuce in western australia. Lettuce may be referred to as garden lettuce and is believed to originate from asia minor and the middle east. The worst affected plants are often stunted and rarely. Infected seed is the most common source of infection. Molecular genetic characterisation of mirafiori lettuce.
Hayes et al pathogen responsible mirafiori lettuce virus. 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. Resistance of wild lactuca genetic resources to diseases. Lettuce bigvein disease is a disease thats been the subject of some controversy in the scientific community in recent years. Description and sympotoms lettuce bigvein disease has been known in the u. Lettuce bigvein associated virus lbvav is also frequently identified in symptomatic plants, but no causal relationship has been demonstrated. Lettuce bigvein disease bvd affects all major lettuceproducing areas of the world. Citrus psorosis cpsv and mirafiori lettuce bigvein virus milbvv belong to the family ophioviridae, plant viruses with filamentous nucleocapsids and segmented genomes of negative polarity, causing. Phylogenetic analysis of the viral polymerase gene consistently places the genus with its type species. Lettuce necrotic yellow virus how is lettuce necrotic. Common symptoms of lbv include ruffled or malformed.
Lettuce big vein virus lettuce bigvein lbv, is a viral disease which is transmitted from plant to plant by the soilborne fungus olpidium brassicae. Lettuce lactuca sativabig vein pacific northwest pest. Several studies have associated this disease with mirafiori lettuce bigvein virus. Lettuce big vein is an important disease of lettuce lactuca sativa l. 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. Lettuce bigvein associated virus lbvav is a pathogenic plant virus. Lettuce bigvein disease causes leaf distortion and ruffling in affected lettuce plants this disease was first associated in 1983 with a rodshaped virus named lettuce bigvein associated virus lbvav. These symptoms resemble those caused by lettuce bigvein disease lbvd, an important disease of lettuce worldwide. Occurrence of mirafiore lettuce virus and lettuce bigvein virus. Occurrence and partial characterization of lettuce big. Lettuce bigvein disease causes leaf distortion and ruffling in affected lettuce plants. The reported variation in the reaction of wild lactuca species to pathogens and pests is summarized, including viral pathogens e.
A, particles of lettuce bigvein virus isolate br8 from crude sap of lettuce infected by mechanical inoculation. Occurrence of mirafiori lettuce virus and lettuce bigvein. 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. The virus is seedborne and overwinters in wild hosts and weeds. Pdf further evidence of mirafiori lettuce bigvein virus. The leaves stiffen and the veins turn a light colour and become more pronounced. Host resistance to mirafiori lettuce bigvein virus and. Viruses are a major cause of loss in many australian vegetable crops. It is certain, however, that this viral disease is transmitted by an oomycete, olpidium virulentus, previously known as o.
However, lettuce bigvein disease, although long thought to be induced by a virus previously designated lettuce bigvein virus, is now considered to be caused by isolates of the species mirafiori lettuce big. Big vein is more prevalent and severe during cool spring weather. Characterization of lettuce bigvein associated virus and. The causal agent is mirafiori lettuce bigvein virus mlbvv, an ophiovirus transmitted by the soilborne. It causes chlorophyll clearing of the veins of the lettuce leaf, leaf crinkling and. Lettuce bigvein associated varicosavirus wikispecies. Lettuce mosaic virus ndash lmv, mirafiori lettuce viruslettuce big. Even though the virus is soilborne and therefore always present in infested fields, disease severity may vary greatly from season to season. Detection of varicosavirus and ophiovirus in lettuce associated with lettuce bigvein symptoms in brazil. Big vein bv is an economically damaging disease of lettuce lactuca sativa l. Common symptoms of lbv include ruffled or malformed leaves with enlarged clear veins.
Read comparison of the coat protein genes of lettuce big vein associated virus isolates from australia with those of isolates from other continents, archives of virology on deepdyve, the. How to deal with bigvein virus and tipburn in lettuce. 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. Abstract california lettuce research board for the. Citrus psorosis and mirafiori lettuce bigvein ophiovirus. Although big vein is a perennial problem in the united states, the extent of mlbvv and lbvav infection and diversity is unknown. Detection of varicosavirus and ophiovirus in lettuce. Comparison of the coat protein genes of lettuce big vein. General information about lettuce bigvein associated varicosavirus lbvv00. If you desire to recieve a personal copy with price information. Available resistance can be described as resistance against big vein.
This disease was first associated in 1983 with a rodshaped virus named lettuce bigvein associated virus lbvav, which is transmitted by the obligately parasitic soilinhabiting fungus, olpidium brassicae. Maccarone ld 2009 molecular genetic characterization of mirafiori lettuce bigvein virus and lettuce bigvein associated virus and their vector olpidiumvirulentus associated with lettuce big. The emerging lettuce big vein disease lbvd is causing losses in lettuce production ranging from 30 to 70% worldwide. Lbvv is defined as lettuce bigvein virus somewhat frequently. Lettuce big vein virus lbvv is a plant pathogenic virus. New dna equipment reveals risk of socalled symptomfree. Transfer resistance from cultivar pavane into iceberg type breeding lines, continued greenhouse and field tests. The lettuce plant can grow to a height of 30100 cm 1240 in in height and is typically grown as an annual, harvested after only one growing season. Although bigvein virus stays in the land once it is introduced in the soil, all is not lost. Identification of mirafiori lettuce bigvein virus and. For several decades, it was believed to be caused by the lettuce bigvein associated virus lbvav.
Virus diseases of lettuce in brazil global science books. Bigvein disease bv of lettuce has been attributed to infection by lettuce bigvein virus lbvv, vectored by the soil fungus olpidium brassicae. Several studies have associated this disease with mirafiori lettuce. Small rnaseq to characterize viruses responsible of. If it isnt the slugs or other insects devouring the tender leaves, its a disease like lettuce big vein virus. Leaves can be smooth or curly and are usually green or red in color. Lettuce isnt difficult to grow, but it sure does seem to have its share of issues. Discoveries in the last years have shown that it is in fact caused by the mirafiori lettuce virus milv. Lettuce big vein agent lbva is probably caused by a virus. Mirafiori lettuce bigvein virus mlbvv formerly known as mirafiori lettuce virus has been recently identified as a causal agent of big vein while lettuce bigvein associated virus lbvav formerly known as lettuce bigvein virus, previously thought to cause big vein, is yet to be confirmed as a causal agent.