An emerging virus isolated from papaya (Carica papaya) crops in northwestern (NW) Argentina was sequenced and characterized using next-generation sequencing. The resulting genome is 6667-nt long and encodes five open reading frames in an arrangement typical of other potexviruses. This virus appears to be a novel member within the genus Potexvirus. Blast analysis of RNA-dependent RNA polymerase (RdRp) and coat protein (CP) genes showed the highest amino acid sequence identity (67% and 71%, respectively) with pitaya virus X. Based on nucleotide sequence similarity and phylogenetic analysis, the name papaya virus X is proposed for this newly characterized potexvirus that was mechanically transmitted to papaya plants causing chlorotic patches and severe mosaic symptoms. Papaya virus X (PapVX) was found only in the NW region of Argentina. This prevalence could be associated with a recent emergence or adaptation of this virus to papaya in NW Argentina.

Tomato (Solanum lycopersicum) ranks as the most important crop among greenhouse-planted crops in terms of cultivated areas (17,800 ha) and production in Argentina. In September 2014, farmers reported that tomato plants of cv. Elpida (Enza Zaden) showed mosaic and blistering on leaves in La Plata (Buenos Aires green-belt). The diseased plants occurred together in the same line, showing a typical pattern of mechanically transmitted pathogens. Although incidence did not exceed 1.5%, it was distributed in several distant locations within the district, posting a serious threat to the tomato production. Five samples were collected from symptomatic plants and tested for tospovirus, begomovirus and Cucumber mosaic virus by reverse transcription polymerase chain reaction (RT-PCR) (Dewey et al., 1996), PCR (Rojas et al., 1993) and enzyme-linked immunosorbent assay (ELISA), respectively. All results were negative. The samples were then examined under transmission electron microscopy. Isometric virus-like particles o...

We report for the first time the presence of phytoplasmas in association with Plum (Prunus domestica) yellowing in Argentina. Molecular analysis of 16S rDNA gene sequence (RFLP, phylogeny) reveals the existence of two different 16Sr-subgroups, 16SrIII-B and novel 16SrXIII-L. These results contribute to a better understanding of the diversity of phytoplasmas associated with Prunus genera in South America.

Broad bean ( Vicia faba L) is the fourth most important pulse crop in the world. In Argentina, broad bean production was of 1,841 hectares and 16,500 tons during the 2017 growing season. Broad bean is commonly used in rotations; especially by farmers located in “green belts” that are peri-urban areas surrounding large cities that include horticultural family farms. Plants showing marked foliar mosaic symptoms, typical of viral infection, were collected during the 2015 growing season in the green belt of Córdoba city, Argentina. Preparations of symptomatic tissues were mechanically inoculated onto healthy broad bean plants in the greenhouse, which developed symptoms similar to those observed in the field. In addition, symptomatic samples were positive when tested by indirect ELISA with the anti - potyvirus group monoclonal antibody. Further, flexuous filamentous particles typical of potyviruses were observed under the electronic microscope on dip preparations. Lastly, total RNA was extracted from a symptomatic leaf and high-throughput sequenced, which allowed the assembly of a single virus sequence corresponding to a new highly divergent strain of Bean yellow mosaic virus (BYMV). Phylogenetic insights clustered this Argentinean broad bean isolate (BYMV-ARGbb) within group IX of BYMV. Given the economical importance of this virus and its associated disease, the results presented here are a pivotal first step oriented to explore the eventual incidence and epidemiological parameters of BYMV in broad bean in Argentina.

An emerging virus isolated from papaya ( Carica papaya ) crops in northwestern (NW) Argentina was sequenced and characterized using next-generation sequencing. The resulting genome is 6,667-nt long and encodes five open reading frames in an arrangement typical of other potexviruses. This virus appears to be a novel member within the genus Potexvirus . Blast analysis of RNA-dependent RNA polymerase (RdRp) and coat protein (CP) genes showed the highest amino acid sequence identity (67% and 71%, respectively) with pitaya virus X. Based on nucleotide sequence similarity and phylogenetic analysis, the name papaya virus X is proposed for this newly characterized potexvirus that was mechanically transmitted to papaya plants causing chlorotic patches and severe mosaic symptoms. RT-PCR based detection of papaya virus X (PapVX) revealed that it is widely present in papaya crops from NW Argentina. The prevalence of PapVX, which seems to be restricted to the NW region of Argentina, and the fact that it has only been detected in this region could be associated with a recent emergence or adaptation of this virus to papaya in NW Argentina.