First report of southern bean mosaic virus infecting common bean in Zambia.
During surveys conducted in the Eastern Province of Zambia in April 2018, several common bean (Phaseolus vulgaris) plants were observed with virus-like symptoms such as vein clearing, leaf rolling, mosaic, and leaf narrowing. Incidence of symptomatic plants across 20 fields ranged from 23 to 100%, averaging 67.5%. A total of 121 symptomatic leaf samples were collected from 20 farmers' fields and preserved dry on silica gel. De novo assembly resulted in the detection of Southern bean mosaic virus (SBMV), bean common mosaic necrosis virus, bean common mosaic virus, cowpea aphid-borne mosaic virus, and cucumber mosaic virus in the sample. RT-PCR confirmed 25 of the 121 samples (20.7%) tested positive only for SBMV, whereas the remaining 96 samples had different combinations of the other four viruses. It is thought that this is the first report of SBMV infecting common bean in Zambia.