Evaluation of resistance to Tomato severe rugose virus (ToSRV) in Capsicum spp. genotypes

Tomato severe rugose virus (ToSRV) is the predominant species of begomovirus in São Paulo State, Brazil, and infects primarily tomato and pepper plants. There is no information about genetic resistance of pepper to this virus, so in this work the reaction of 29 genotypes of Capsicum spp. was evaluated by inoculation of two ToSRV isolates: ToSRV-Sk (isolated from a tomato plant) and ToSRV-PJU (isolated from a pepper plant). For both isolates, two C. annuun genotypes (Catarino Cascabel - México and Silver) showed no symptoms 30 days after inoculation (d.a.i). In a second experiment, these two genotypes were evaluated for 150 d.a.i and, again, no symptoms could be observed. However, the virus was detected by RCA-PCR, indicating that both genotypes are susceptible, but less affected by ToSRV infection. Catarino Cascabel - México and Silver can be indicated for use in breeding programs for resistance of pepper to ToSRV

A classification of Pepper yellow mosaic virus isolates into pathotypes

Pepper yellow mosaic virus (PepYMV) is the most important potyvirus infecting sweet pepper in Brazil. In this study, twenty isolates of PepYMV were obtained from commercial sweet pepper crops. To confirm virus identity, the coat protein gene was completely sequenced for eleven of these isolates, and partially sequenced for the other nine isolates. The amino acid identities obtained were above 93% when compared with the sequence of a characterized PepYMV isolate (AF348610). Extracts of Nicotiana tabacum cv. TNN plants infected with the different isolates were used to inoculate the differential series of Capsicum spp cultivars containing the genes pvr2(1), pvr2(2), pvr2(3), pvr2(4), and Pvr4. Using the same criteria established for Potato virus Y (PVY), fourteen isolates of PepYMV could be classified as known pathotypes described for PVY, that is: 1.2 (2 isolates), 1.3 (6) and 1.2.3 (6). The remaining six isolates, 1.3 (2) and 1.2.3 (4) could not be classified into the typical pathotypes of PVY because they were also virulent on Serrano Criollo de Morellos-334 (C.M 334) which carries the pvr2(3) and Pvr4 genes. To classify the PepYMV into pathotypes and counter the biological diversity found in this species we propose the utilization of 2(x) for the ability to overcome the correspondent allele of the pvr2 locus and 4 for the capacity to break down the Pvr4 gene. Using this criterion we could classify the PepYMV into five pathotypes: 2(1).2(2); 2(1).2(3); 2(1).2(2).2(3); 2(1).2(3). 4 and 2(1).2(2).2(3). 4.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Indigenous American species of the Bemisia tabaci complex are still widespread in the Americas

Bemisia tabaci is a complex of at least 36 putative cryptic species. Since the late 1980s, the Middle East-Asia Minor 1 species (MEAM1, formerly known as the B biotype), has emerged in many tropical and subtropical regions of the world and in some areas has displaced the indigenous populations of B. tabaci. Based on analysis of the mtCOI gene, two indigenous species native to America have been reported: New World (NW, formerly the A biotype) and New World 2 (NW2). NW is present at least in Argentina, Brazil, Martinique, Mexico, Texas and Venezuela, and NW2 in Argentina, Bolivia and Brazil. Wild plants (Euphorbia sp. and Ipomoea sp.), as well as important crops such as tomato, bean and cotton, are still hosts for native B. tabaci populations in the Americas. MEAM1 has not completely displaced the native B. tabaci from the Americas. (C) 2014 Society of Chemical IndustryConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES