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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Molecular Plant Pathology Laboratory » Research » Publications at this Location » Publication #318510
Title: Citrus leprosis research update

Author
item BRLANSKY, RONALD - University Of Florida
item Roy, Avijit
item Schneider, William
item Hartung, John

Submitted to: Citrus Industry
Publication Type: Trade Journal
Publication Acceptance Date: 7/25/2015
Publication Date: 8/1/2015
Citation: Brlansky, R.H., Roy, A., Schneider, W.L., Hartung, J.S. 2015. Citrus leprosis research update. Citrus Industry. 20-22.

Interpretive Summary: Citrus leprosis is one of the most important emerging citrus diseases in South and Central America, and is spreading northward towards the U.S. The cause of citrus leprosis has always been considered to be a virus transmitted by a flat mite. Research in our labs has shown that citrus leprosis disease is in fact caused by a complex of viruses and that five different viruses currently present in South, Central and North America (Mexico) can cause the disease. The diversity of viruses is also matched by a previously unexpected diversity in the flat mites associated with the disease. Specific detection methods are now in place for diagnosis of the known viruses that cause citrus leprosis and plans are to combine them into a multiplex assay. A recovery plan is in place with the USDA in case the disease should be introduced into the U.S.

Technical Abstract: Citrus leprosis is one of the oldest citrus diseases, but is also one of the most important emerging citrus diseases in South and Central America, and it is apparently spreading northward towards the U.S. Research in our labs and by others has shown that citrus leprosis disease is caused by a complex of viruses and that five different viruses currently present in South, Central and North America (Mexico) can cause the disease. This was made possible by using modern molecular technology (Next Generation Sequencing), and the associated analysis. The new techniques have made the identification and characterization of these unknown viruses quicker. The citrus leprosis-associated viruses are present in either the cytoplasm or the nucleus of the cells. However the symptoms produced in citrus by most of them are very similar. The diversity of viruses is also matched by a previously unexpected diversity in the flat mites associated with the disease. So far, two species of Brevipalpus (flat) mites are involved. Recent sequence analysis of these cytoplasmic leprosis viruses have revealed a close relationship with virus sequences found in mosquitos and therefore suggests that the genus Cilevirus, to which these viruses belong, may have originally evolved in mites and that citrus may actually be a secondary host. Specific detection methods are now in place for diagnosis of the known viruses that cause citrus leprosis and plans are to combine them into a multiplex assay. A recovery plan is in place with the USDA in case the disease should be introduced into the U.S.