Disease Note

Seed Transmission of Blackeye Cowpea Mosaic Virus in Vigna mungo. R. Provvidenti, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456. Plant Dis. 70:981. Accepted for publication 12 June 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-981e.

During greenhouse evaluations of leguminous species for disease resistance, viral symptoms were noted on seedlings of an accession of urd bean (Vigna mungo (L.) Hepper). Seeds of PI 222823 were collected at Bukan, Western Azerbaijan (Iran) in 1954 and erroneously listed as mungo bean (V. radiata (L.) Wilczek). The original collection was sent to the USDA Northeast Regional Plant Introduction Station. Geneva, NY, from which we obtained a sample years later. Symptoms consisted of a diffuse green mottle, foliar cupping along the main vein, and plant stunting. The causal agent was identified as blackeye cowpea mosaic virus (BICMV) by electron microscopy, serology, host range, and absence of infection in the cowpea line TVU 2480, which possesses a specific gene for resistance to BICMV. In the original seed lot, the rate of virus transmission was 14%. However, a higher proportion of BICMV-infected plants was detected in progenies of individual plants, ranging from 20 to 48%. Before planting, seed lots had been kept in storage for 3 yr. In BICMV-infected seed, the virus was recovered from embryos but not from testae. This is believed to be the first report of seed transmission of BICMV in V. mungo.