Occurrence of cowpea aphid-borne mosaic virus in peanut in Brazil

Surveys of groundnut crops in northeastern Brazil since 1995 showed the occurrence of a hitherto unreported virus disease. Characteristic leaf symptoms were ring spots and blotches. The virus was seed transmitted in groundnut (1/610) and cowpea (47/796). Local and systemic symptoms were observed in cowpea (cv. TVu 3433) known to be susceptible to most cowpea aphid-borne mosaic virus (CABMV) isolates. The virus was transmitted by aphids Toxoptera citricidus and Aphis gossypii. Using degenerate primers, the 3′ terminal region of the viral genome was cloned and sequenced. Sequence analyses of the coat protein and the 3′ untranslated region indicated that the potyvirus was most closely related to CABMV isolates from South Africa, Zimbabwe, and the United States. On the basis of genome analysis, the virus was identified as CABMV. The natural occurrence of CABMV on groundnut has so far not been reported. The significance of this finding especially for germplasm exchange is discusse