Yardlong bean (Vigna unguiculata subsp. sesquipedalis) plants with virus-like systemic mottling and leaf distortion were observed in both experimental and commercial fields in Aragua State, Venezuela. Symptomatic leaves were shown to contain carlavirus-like particles. RT-PCR analysis with carlavirus-specific primers was positive in all tested samples. Nucleotide sequences of the obtained amplicons showed 84%–74% similarity to corresponding sequences of Cowpea mild mottle virus (CPMMV) isolates deposited in the GenBank database. This is the first report of CPMMV in Venezuela and is thought to be the first report of CPMMV infecting yardlong bean.
We report the complete nucleotide sequence of a begomovirus isolate infecting Euphorbia heterophylla and tomato (Solanum lycopersicum) in central Venezuela. Based on the current taxonomic criteria for the genus Begomovirus, the isolate was shown to represent a novel species, tentatively named Euphorbia mosaic Venezuela virus (EuMVV). Its DNA-A is most closely related to those of Euphorbia-infecting begomoviruses from the Caribbean and Central America. The DNA B component forms a phylogenetic cluster with Euphorbia and Sida-infecting begomoviruses from the squash leaf curl virus (SLCV) cluster. EuMVV is transmissible to S. lycopersicum and Capsicum annuum by biolistics of infectious cloned DNA-A and DNA-B components and induces characteristic leaf downward curling and yellowing in S. lycopersicum and and yellowing and leaf distortion in Capsicum annuum.
The genetic variation of papaya ringspot virus (PRSV) in Venezuela was estimated by single strand conformation and nucleotide sequence analyses of two genomic regions of twenty-six isolates. These analyses showed that mutation, virus movement, selection, mixed infections and recombination contributed to shape the genetic variation observed. Phylogenetic analysis indicated that Venezuelan isolates were within a clade composed of isolates from the Americas and Australia. The genetic diversity of these isolates was sufficiently large that it must be taken into account when designing control strategies such as transgenic resistance and cross-protection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.