Present status of citrus leprosis in Argentina and Paraguay

Abstract

Citrus leprosis (CL) was first described in South America in the 1920's. It is considered similar to a disease first observed back to 1860 in Florida. It is a destructive disease characterized by localized lesions on the leaves, fruits and stems, which may lead to the death of the affected plant if left untreated. Around 1940, CL was demonstrated to be transmitted by Brevipalpus mites in Argentina. Because little information exists on the status of CL pathosystem in Argentina and Paraguay, a survey was made in several citrus growing areas of these countries from 2009 to 2011, to evaluate its presence and relevance as well as the identification of the virus and the mite vector. CL was found in most of the sweet orange and/or mandarin orchards in Paraguay (Departamentos de Boquerón, Concepción, San Pedro, Cordillera, Alto Paraná, Itapúa) and Argentina (Provincias de Misiones, Corrientes, Entre Ríos). Incidence was usually low. The causal virus was identified as Citrus leprosis virus C (CiLV-C) by RT-PCR, electron microscopy and immunofluorescence. In all the visited regions in Paraguay and the region of Montecarlo, Argentina, the mites collected in plants infected by CiLV-C were identified as B. phoenicis.

Phylogenetic and Molecular Variability Studies Reveal a New Genetic Clade of Citrus leprosis virus C

“…In these trees, most of the isolates grouped together with those with known full-length genomes i.e. , CiLV-C isolates PA01 and BR_SP_JBT_01 [ 32 , 34 ] and particularly with the isolate BR_SP_CRD_01, the type member of the cilevirus genus and up to now recognized as the only genotype of the species [ 8 , 22 ]. This group was called CRD, abbreviation used to refer to the Cordeirópolis city in the São Paulo State, Brazil, place of collection of the isolate BR_SP_CRD_01 [ 32 ].…”

“…Even though plant species belonging to 28 families can be experimentally infected by CiLV-C, the known natural host range of the virus is limited to a few species (tropical spiderwort, citrus and Swinglea glutinosa ) and in both natural and experimental hosts, the virus does not spread systemically [ 17 , 26 , 27 , 78 , 79 ]. Consequently, after multiplication in a relatively low number of epidermal and parenchymal cells around the mite feeding sites [ 8 , 26 , 27 , 80 ], CiLV-C colonization to distal parts of the infected plant is exclusively mediated by viruliferous mites. Recently, new evidence indicating multiplication of cileviruses in mites have been suggested [ 1 ].…”

“…Endemic in the Americas, leprosis was first observed in Florida, USA, São Paulo State, Brazil, and restricted areas of Argentina and Paraguay at the beginning of the 20th century [ 2 , 3 , 4 , 5 ]. After the 1960s, the disease disappeared from Florida [ 6 ], but in the Southern region of South America it became prevalent occurring in most of the Brazilian citrus growing areas [ 7 , 8 ]. More recently, Bolivia, Colombia, Venezuela, all of the Central American countries and Mexico have been incorporated to the citrus leprosis distribution map [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

Space–time variability of citrus leprosis as strategic planning for crop management

“…The costs to the Brazilian citrus industry of acaricides are estimated to be more than US$ 80 million per year . An imbalance between natural and cropped environments, together with unreliable management practices have contributed to the spread of the disease around Latin America . Even with current control practices, the disease continues to spread, especially towards North America.…”

Sequenciamento e análise da variabilidade genética de vírus transmitidos por ácaros do gênero <i>Brevipalpus </i>no Brasil

“…A leprose dos citros se tornou prevalente na América do Sul, ocorrendo na maioria dos estados brasileiros (BASTIANEL et al, 2006;CÁCERES et al, 2013). Chenopodium amaranthicolor e C. quinoa (COLARICCIO et al, 1995).…”