Potato virus M in Bittersweet Nightshade (Solanum dulcamara) in New York State.

Potato virus M (PVM) was detected in upstate New York in two plants of the widely naturalized, weedy perennial Solanum dulcamara. The virus was detected with a macroarray assay for potato viruses (1). Amplified, complimentary DNAs from the two isolates hybridized to 5 and 7 of the 15 oligonucleotide probes for PVM. Testing of the samples by double-antibody sandwich-ELISA using PVM-specific antibodies (Agdia, Elkhart, IN) showed a clear positive result. Sequence information for a 118-bp genomic region was obtained by amplification using carlavirus-specific primers (2) (GenBank Accession No. HQ446853). Comparison with a reference PVM genome (GenBank Accession No. NC_001361) showed that the sequence corresponded to nucleotide positions 8418 to 8533 with 86% identity. The infected plants were symptomless and collected from two sites, 50 miles apart. One site was a weedy roadside location in Tompkins County in 2009, while the second was from a hedgerow in a (non-potato) vegetable production area of Ontario County in 2010. The virus could be detected throughout the growing season in this perennial host. PVM was reported from S. dulcamara L. in Hungary and described as being found frequently from a diversity of habitats (3). Importantly, the virus was transmitted via tubers and by Myzus persicae with low efficiency (3). These results suggest that the virus may be endemic in S. dulcamara in the northeastern United States and this host may serve as a reservoir for the virus from which it could move into potato. To our knowledge, PVM has not been reported in this host in North America. References: (1) B. Agindotan and K. L. Perry. Plant Dis. 92:730, 2008. (2) J. Badge et al. Eur. J. Plant Pathol. 102:305, 1996. (3) P. Salamon. Eur. Assoc. Pot. Res. Virol. Sect. Meet. 42:121, 2006.