Occurrence of Six Begomoviruses Infecting Tomato Fields in Venezuela and Genetic Characterization of Potato Yellow Mosaic Virus Isolates

Abstract

Begomoviruses are one of the major pathogens in tomato crops worldwide. In Venezuela, six begomovirus species have been described infecting tomato: Potato yellow mosaic virus (PYMV), Euphorbia mosaic Venezuela virus (EuMVV), Merremia mosaic virus (MeMV), Tomato chlorotic leaf distortion virus (ToCLDV), Tomato yellow margin leaf curl virus (TYMLCV) and Tomato yellow leaf curl virus (TYLCV). In this study, the occurrence of these viruses was analysed by PCR in 338 tomato plants exhibiting virus-like symptoms. Sixty-three per cent of the plants were positive at least to one of the begomoviruses tested. PYMV and TYLCV were the most frequent viruses showing 39.6 and 23.7% occurrence, respectively. Phylogenetic analyses revealed two groups of PYMV isolates from several Caribbean Basin countries. The first group clustered isolates from several countries, including Venezuela, and the second group clustered only Colombian isolates. Due to the high prevalence of PYMV and TYLCV in Venezuela, it is suggested that the surveillance and control strategies currently applied in the country should be focused on these two begomoviruses.

Molecular variability of Merremia mosaic virus infecting tomatoes in Venezuela

“…2). This result could be expected due to the traffic of tomato seedlings across the country as was previously observed for Potato yellow mosaic virus (Nava et al 2006;Chirinos et al 2014;Geraud-Pouey et al 2015). According to our results MeMV has a relative high genetic diversity in Venezuela compared to other begomoviruses widespread in the country, like Melon chlorotic mosaic virus (MeCMV), which has a low genetic diversity (NI > 97 %), even when analysing the full DNA-A component .…”

“…Similar ranges of genetic variability have been also reported for other begomoviruses infecting tomato in Latin America (Sánchez-Campos et al 2013;Geraud-Pouey et al 2015). Further analyses of pairwise identity were also Fig.…”

“…In Venezuela, severe begomoviral outbreaks have been reported in tomatoes and other crops Romay et al 2010Romay et al , 2014. Recently, Merremia mosaic virus (MeMV) was found as one of the three more prevalent begomoviruses in Venezuelan tomato fields (Geraud-Pouey et al 2015). It was first reported infecting Merremia quinquefolia.…”

“…Twenty tomato plants, previously identified as positives to MeMV (Geraud-Pouey et al 2015), were selected for molecular analyses. In addition, 70 samples of weeds, exhibiting virus-like symptoms, were also included for molecular detection of MeMV in this work.…”

“…MeMV DNA was amplified by PCR using universal primers PAL1v1978 and PAR1c715 for begomoviruses (Rojas et al 1993), which amplify the common region and part of the genes AV1 and AC1. This genomic region has been previously used to estimate genetic diversity of other begomoviruses from the New World (Nava et al 2006;Sánchez-Campos et al 2013;Geraud-Pouey et al 2015). PCR amplicons were sequenced in both directions using an ABI-3130 genetic analyzer.…”