First report of Bean common mosaic virus, peanut strain, infecting peanut in Argentina.
Peanut or groundnut (Arachis hypogaea) is an important oilseed crop in Argentina, where it is used primarily for direct human consumption (confectionery peanut). In the 2009-10 and 2010-11 cropping seasons, peanut plants with virus-like symptoms were detected in the growing area of Jujuy and Salta provinces, northwestern Argentina, in fields sown with seeds from Bolivia. Leaf symptoms included systemic mild or severe mottling, blotching and stripes along the lateral veins, sometimes with the presence of chlorotic rings, suggesting the presence of Peanut mottle virus (PeMoV) or peanut strain of Bean common mosaic virus (BCMV-PST). A total of 47 symptomatic young leaf samples were collected during both cropping seasons. Serological assays revealed that 21 samples were positive for BCMV, 16 were PeMoV-positive, and 3 were coinfected with the two viruses. RT-PCR assay showed that a single band of the expected size (∼234 bp) was obtained from serologically BCMV-positive samples, whereas samples infected with PeMoV yielded a ∼327-bp fragment. Both fragments were amplified in mixed infections. Total nucleic acids from two samples positive for BCMV were purified using CTAB extraction method and total RNA was sequenced. High-quality sequences were de novo assembled and the identity of contigs was analysed. BLAST analyses successfully identified several contigs corresponding to BCMV-PST genome. This is thought to be the first report of BCMV-PST infecting peanut in Argentina. The virus is transmitted by aphids in a nonpersistent manner and by seeds.