Resumo -O objetivo deste trabalho foi determinar a presença do alelo Pvr4, que confere resistência contra o PepYMV (Pepper yellow mosaic virus), em genótipos de pimentão comunmente encontrados no mercado brasileiro, com uso de um marcador molecular codominante tipo CAPS. A resistência ao PepYMV, nos genótipos CM-334-INRA, Myr-29 e em genótipos derivados do híbrido comercial Mônica-R, foi detectada como associada à banda de 444 pb, ligada ao alelo de resistência Pvr4. As plantas resistentes homozigotas (Pvr4/Pvr4) mostraram uma banda de 444 pb, as suscetíveis (Pvr4 Marker-assisted selection for resistance to potyvirus in sweet pepperAbstract -The objective of this work was to determine the presence of the Pvr4 allele, which controls the resistance to the PepYMV (Pepper yellow mosaic virus), in sweet pepper genotypes commonly available in the Brazilian market, using a CAPS codominant molecular marker. The resistance to PepYMV, in the genotypes CM-334-INRA, Myr-29, and in genotypes derived from the hybrid Mônica-R, was found to be associated with the 444 bp band linked to the resistance allele Pvr4. Homozygous resistant plants (Pvr4/Pvr4) showed a single band of 444 bp, the susceptible ones (Pvr4showed a band of 458 bp, and the heterozygous resistant plants (Pvr4 + /Pvr4) showed both bands. However, in the resistant accession CM-334-UFV, and in the hybrids Magali-R and Martha-R, as well as in populations derived from this accession and these hybrids, the resistance to PepYMV was not associated to the CAPS marker. The accession CM-334-UFV ('Criollo de Morelos-334' from Viçosa, MG, Brazil) was distinct from CM-334-INRA ('Criollo de Morelos-334', from France); although both accessions were resistant to PepYMV, the association of resistance with the 444 bp band was found only in CM-334-INRA.

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The aim of this study was to assess resistance to some of the major sweet pepper pathogens [Phytophthora capsici, Pepper yellow mosaic virus (PepYMV) and Meloidogyne incognita] in a group of experimental hybrids and their respective parental lines, and to identify hybrids possibly resistant to all three pathogens. Ten parental breeding lines, thirty experimental hybrids and seven commercial controls (Konan-R, Magali-R, Martha-R, Stephany, Mallorca, Magnata Super and Criollo de Morelos-334) were used. Each experiment was set up in a randomized complete block design with three replications and plots consisting of 16 plants. For assessment of resistance to P. capsici and PepYMV, the percent of asymptomatic plants was considered. In evaluating reactions to M. incognita, both the nematode reproduction index and the nematode reproduction factor were calculated. Five hybrids were found with resistance to all three pathogens. For all three pathogens, there was evidence that hybrids with two resistant parental lines showed slightly higher levels of pathogen resistance than those with only one resistant parental line.

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Resumo -O objetivo deste trabalho foi associar um marcador microssatélite ao alelo Ty-1 de resistência a Begomovirus em tomateiro, e avaliar a eficiência desta associação na seleção de linhagens resistentes ao vírus. Os marcadores SSR-47 e SSR-48 foram testados em linhagens isogênicas contrastantes quanto à presença do alelo Ty-1 (LA-3473, LA-3474, LA-3475). O marcador SSR-47, por ter detectado polimorfismo nas linhagens, foi o único utilizado nas etapas subsequentes da pesquisa. Detectada a associação entre o SSR-47 e o alelo Ty-1, testou-se sua eficiência na seleção de genótipos avançados de tomateiro. Para confirmar a eficiência da seleção, foi realizada a avaliação fenotípica das plantas com padrões contrastantes de bandas para SSR-47, quanto à resistência a Begomovirus. Plantas que apresentaram banda única de 191 pb foram resistentes ao Begomovirus, pelo teste de inoculação por enxertia; aquelas com banda única de 180 pb foram suscetíveis; e as plantas com bandas de 191 e 180 pb foram resistentes. A distância máxima entre o Ty-1 e o marcador SSR-47 foi de 2,7 cM. Este marcador foi efetivo em caracterizar genótipos portadores do alelo Ty-1. As respostas das plantas à infecção pelo Begomovirus, induzida via enxertia, são consistentes com as reações previstas com o uso do marcador molecular SSR-47.Termos para indexação: Geminiviridae, Lycopersicon esculentum, Solanum lycopersicum, QTL, seleção assistida por marcadores. Microsatelite marker associated with the Ty-1 allele for resistance to Begomovirus in tomatoAbstract -The objective of this work was to associate a microsatellite marker with the Ty-1 allele that controls resistance to Begomovirus in tomatoes, and to assess the eficiency of this association in the selection of virus-resistant lines. Microsatellite markers SSR-47 and SSR-48 were tested in near isogenic tomato lines (LA-3473, LA-3474, LA-3475) with contrasting genotypes for the Ty-1 allele. The marker SSR-47 detected polymorphism in the lines, and was the only one used in the subsequent research phases. An association between the SSR-47 marker and the Ty-1 locus was detected, and its efficiency for selection of begomovirus-resistant genotypes in tomato was assessed. To confirm the selection efficiency, plants with contrasting banding patterns for the SSR-47 marker were tested for their reaction to Begomovirus. All plants with a single 191-bp band were resistant to Begomovirus, through inoculation test by grafting. Plants with a single 180-bp band were susceptible, and plants with both 191bp and 180 bp bands were resistant. The maximum distance between Ty-1 and the SSR-47 marker was 2.7 cM. This marker was efficient to identify genotypes bearing the Ty-1 allele. Plant responses to infection by Begomovirus inoculated through grafting were consistent with reactions predicted with the use of the SSR-47 marker.

The potyvirus Pepper yellow mosaic virus (PepYMV) is the main virus affecting Brazilian pepper (Capsicum annuum) crops and has become a very important factor affecting pepper production in Brazil (Lucinda, da Rocha, Inoue-Nagata, & Nagata, 2012;Moulin et al., 2014). The first reports of the occurrence of this pathogen in Brazil occurred in 1980 in pepper production fields in the states of São Paulo and Minas Gerais, referring to the potyvirus strain originally classified as PVY M by Nagai (1983). However, in 2001, it was recognized as a new potyvirus species, named Pepper yellow mosaic virus (PepYMV) (Inoue-Nagata et al., 2002).The main method to control PepYMV is through genetic resistance (Bento et al., 2013). Several sources of resistance to this virus have been found in Capsicum spp. and this genetic variability has been allowing to effectively control viral diseases belonging to the potyvirus complex (Nogueira et al., 2012). Despite the wide variability of PepYMV-resistant pepper hybrids commercially available, there are reports of resistance suppression by new strains of PepYMV (Lucinda et al., 2012).The main resistance sources to potyviruses carry one of the genes from pvr series, denominated as pvr1, pvr2, pvr3, Pvr4, pvr5,