First report of apple stem pitting virus on pear and quince orchards in northern Turkey.

Abstract

The Bursa and Sakarya provinces in the south eastern part of Marmara region in Turkey [(39°.341) -41°.101 N, 28°.051-30°.541 E] are very important fruit-growing areas. Leaf samples from 12 symptomless pear trees and six quince trees showing typical symptoms of quince fruit deformation disease (Nemeth, 1986), including leaf chlorosis and curling, mosaic, vein banding, and deformation, were collected in June 2009 and tested for the presence of Apple stem pitting virus (ASPV), genus Foveavirus, family Flexiviridae. RT-PCR for the generic detection of foveaviruses was used with degenerate primers that target a conserved region of the RNA-dependent RNA polymerase gene, followed by a nested PCR that amplifies a 312 bp ASPV-specific product (Mathioudakis et al., 2009). The virus was present in all pear and quince samples tested (GenBank accession Nos FN432827 and FN432828, respectively). Direct sequencing of two RT-PCR amplicons, one from pear and one from quince, confirmed the identification of ASPV. The pear isolate (ASPV-Pe) showed 83.0% nucleotide sequence identity with a pear isolate of ASPV (accession No. FN386784) whereas the quince isolate (ASPV-Qui) showed 84.0 % nucleotide sequence identity with an apple isolate of ASPV (accession No. FN386781). Nucleotide sequence comparison among ASPVPe and ASPV-Qui isolates revealed a 78.7% similarity. To our knowledge, these findings represent the first report of ASPV in pear and quince orchards in northern Turkey.