First Report of Rubus yellow net virus on Rubus idaeus in Alberta, Canada.

Abstract

In North America, Rubus yellow net virus (RYNV), a member of the genus Badnavirus, family Caulimoviridae, is vectored in a semipersistent manner by the large raspberry aphid (Amphorophora agathonica Hottes) and is responsible for producing net-like chlorosis of tissue along the leaf veins (2). Red raspberry (Rubus idaeus L.) is commonly grown in Canada and after the dry, hot summer of 2006 in southern Alberta, a group of garden raspberry plants located near Lethbridge, Alberta exhibited interveinal chlorosis resembling viral symptoms. Nonenveloped, 140 × 30 nm, bacilliform particles typical of badnaviruses were observed in infected leaves by transmission electron microscopy. The presence of RYNV was confirmed by immunocapture of virions from extracts of symptomatic leaves using Sugarcane bacilliform virus polycolonal antiserum (Agdia Incorporated, Elkhart, IN) followed by PCR amplification of a 451-bp fragment with RYNV-specific primers based on the highly conserved region of the reverse transcriptase and ribonuclease H genes (5'-ATCCTCAAAGGGTTACGTAGCTGGTT-3' and 5'-TTCAAGCCACCTTACCCTCGAAGGTTT-3'). Sequence of clones from the PCR product (GenBank Accession No. EU327346) showed 87% identity to a previously sequenced isolate of RYNV (GenBank Accession No. AF468454) (1). To our knowledge, this is the first report of RYNV in Alberta, Canada, and as an important component of raspberry veinbanding disease, it poses a new threat to the Alberta raspberry industry.