03582nam a2200277 a 450000100080000000500110000800800410001910000170006024500720007726001440014950001050029352026590039865000250305765000260308265000220310865000110313065300180314170000160315970000140317570000190318970000160320870000250322470000180324970000170326770000200328418699912015-09-28       2010    bl uuuu     u00u1 u    #d1 aCÁCERES, S.  aPresent situation of the citrus leprosis in Argentina and Paraguay.  aIn: CONFERENCE INTERNATIONAL ORGANIZATION CITRUS VIROLOGISTS, 18., Campinas, SP, 2010. Proceedings... Campinas: IOCV, 2010. 1 CD-ROM.c2010  a054 PSO. Publicado também em: Citrus Research & Technology, Cordeirópolis, v. 31, Suplemento, 2010  aCitrus leprosis was first reported in South América in Paraguay and Argentina in the 1930?s and referred to as ?lepra explosiva?. Symptom comparison with the ?scaly bark? and ?nail head rust? described in Florida since the beginning of the 20th century led to the conclusion that both diseases were the same. First evidences of the involvement of the tenuipalpid mite Brevipalpus obovatus in the transmission of the disease were produced at Bella Vista and Concordia, Argentina. Further studies confirmed that CL was viral in nature and is caused largely by the Citrus leprosis virus cytoplasmic type (CiLV-C) and very rarely by the nuclear type (CiLV-N). Argentina occupies the 5th place in the world in fresh fruit citrus production, with ca. 140,000 Ha of planted area and an yield of 3 million tons. Most of sweet oranges and mandarins are planted in the Northern provinces (Misiones, Corrientes and Entre Ríos), usually in small orchards, for table and industry, totaling ca. 30,000 Ha. Leprosis occurs endemically but erratically in these regions, mostly in sweet orange. There is no systematic control of the mite vector, but a combination of pruning and chemical control of the mite has been successful. Analysis made on symptomatic leaves, collected from sweet orange and mandarins grown at Provinces of Missiones, Corrientes and Entre Ríos, by transmission electron microscopy (TEM) and RT-PCR confirmed that the causal agent of leprosis is CiLV-C. Mites collected from sweet orange in B.Vista and Concordia revealed a mixed infestation by B. phoenicis and B. obovatus, but from a mandarin in Bella Vista, only B. phoenicis was found. Interestingly, among the mixed infestation in sweet orange in these two areas, adult females with asymmetric number of solenidion in the tarsus of leg II were found, whose nature is not yet known. Which among these mites in mixed infection transmit the virus is still an open question. In Paraguay, sweet oranges are cultivated, usually in small properties, in the Dept. Itapua, Alto Paraná, Cordillera and Boquerón, totaling ca. 12,000 Ha. Leprosis was found endemically infecting sweet orange in most of visited orchards, and the causal virus identified as CiLV-C by TEM and RT-PCR. Mites were collected only in sweet oranges from Boquerón, and identified as B. phoenicis. In general, in Argentina and Paraguay, leprosis is not considered as a major disease and there is no special program to control the mite vector. Genome from isolates of CiLV-C from Argentina and Paraguay were not significantly different from other isolates, which is coherent to the view that this virus has a small variability.  aBrevipalpus obovatus  aBrevipalpus Phoenicis  aDoença de Planta  aVírus  aPlant disease1 aAGUIRRE, A.1 aCOSTA, N.1 aSEGAÑA, L. G.1 aFARIÑA, N.1 aFREITAS ASTUA, J. de1 aMORAES, G. J.1 aTASSI, A. D.1 aKITAJIMA, E. W.