Molecular characterisation and relative incidence of bean- and soybean-infecting begomoviruses in northwestern Argentina

Recent studies identified three begomoviruses infecting soybean and bean crops in northwestern (NW) Argentina, bean golden mosaic virus (BGMV), a virus with high capsid protein identity with Sida mottle virus (SiMoV) and a possible new viral species (isolate A). Analysis of complete DNA-A sequences confirmed that isolate A represents a new viral species for which the authors propose the name soybean blistering mosaic virus (SbBMV), whereas the SiMoV-like virus is actually an isolate of tomato yellow spot virus (ToYSV). Molecular hybridisation-based detection of the three begomoviruses was accomplished using a general probe obtained by mixing full-length DNA-A clones of the three begomoviruses and specific probes comprising part of the common region of each viral genome. These probes were used to test samples collected in NW Argentina from 2004 through 2007. Fifty-three percent of the bean samples were infected with BGMV, 11.5% with ToYSV and 9% with SbBMV. For soybean samples, 33% were infected with SbBMV and 18% with ToYSV. BGMV was not detected in soybean. ToYSV was also detected in the wild species Abutilon theophrasti.