RT-PCR Detection of Seedborne Cowpea aphid-borne mosaic virus in Peanut

In 1995, Cowpea aphid-borne mosaic virus (CABMV) of the family Potyviridae was reported to infect peanut (Arachis hypogaea L.) in Brazil (6). Leaf symptoms consisted of ring spots and blotches, and virus incidence was high when peanut was intercropped with cowpea (Vigna unguiculata (L.) Walp. subsp. unguiculata). CABMV was seed transmitted at approximately 0.15% in peanut and 6% in cowpea (6) and efficiently vectored by aphids (Aphis gossypii Glov. and Toxoptera citricidus Kirk.). In the United States, the National Plant Germplasm peanut collection is maintained at Griffin, GA and receives regular shipments of seed from countries where CABMV is known to be present. Serological detection by direct antigen coating enzyme-linked immunosorbent assay (DAC-ELISA) is used to identify infected plants and detect virus in seed lots. However, a method to assay larger seed lots and groups of plants was needed to improve virus detection sensitivity. Previously, an immunocapture-reverse transcription-polymerase chain reaction (ICRT-PCR) was developed for the large-scale assay for Peanut stripe virus (PStV) and Peanut mottle virus (PeMV) (3). This article presents information on the use of RTPCR for the detection of CABMV in large numbers of seed and leaf samples.