Detection and identification of the blackeye cowpea mosaic strain of Bean common mosaic virus in seeds of cowpea from southern India

Abstract

In different legume-growing regions of India, a total of 136 seed samples of cowpea (Vigna unguiculata (L.) Walp.) were collected and tested for the presence of the blackeye cowpea mosaic strain of Bean common mosaic virus, Cowpea aphid-borne mosaic virus, Cowpea mosaic virus, Cucumber mosaic virus and Bean yellow mosaic virus using growing-on test, enzyme linked immunosorbent assay, differential host test, electron microscopy and immuno-capture reverse transcription polymerase chain reaction. Among the 136 seedlots tested, 43 cowpea seedlots were found to be infected with BCMV-BlCM. The identity of three of these isolates as BCMV-BlCM was further supported by nucleotide sequencing in the 3′ region of the genome. The incidence of seeds carrying transmissible virus ranged from 0.67% to 13.49%. In most cases, only symptomatic seedlings in a growing-on test were found infected with the virus.