First Report of Phaeomoniella chlamydospora on Vitis vinifera, Vitis labrusca, and French American Hybrids in Pennsylvania and New York. E. L. Stewart and N. G. Wenner, Department of Plant Pathology, The Pennsylvania State University, University Park 16802; and B. E. Hed, Lake Erie Research and Extension Center, North East, PA 16428. Plant Dis. 87:750, 2003; published on-line as D-2003-0404-01N, 2003. Accepted for publication 5 March 2003.

Phaeomoniella chlamydospora (W. Gams, Crous, M.J. Wingfield. & L. Mugnai) Crous & Gams (= Phaeoacremonium chlamydosporum) was isolated during the growing seasons of 2001 and 2002 from roots, trunks, and cordons of grapevines including cultivars Concord, Niagara, Steuben, Catawba, Dutchess, DeChaunac, Vidal, Seyval, Chambourcin, Chardonnay, Riesling, Sangiovese, Dolcetto, Baco Noir, Merlot, Villard, Pinot Gris, GR7, and 3309C root stock representing 18 locations in Eastern, Central, and Lake Erie regions of Pennsylvania as well as the Lake Erie and Finger Lakes regions of New York. P. chlamydospora was isolated from 89% of samples from vines 3 to 45 years old showing decline symptoms in the field. Isolates were identified based on a previous description (1) and by internal transcribed spacer (ITS1–5.8S–ITS2) rDNA sequences identical to those of P. chlamydospora isolated from Vitis vinifera from Italy (ex-type culture CBS229.95, GenBank Accession No. AF197973). P. chlamydospora is firmly established as a member of the petri and esca disease complex and as a pathogen of grapevines (2,3). To test pathogenicity of our isolates, approximately 30 µl of a 10(^6) conidia/ml suspension, obtained from six isolates, was injected into the pith of 60 single-node, dormant, unrooted cuttings of ‘3309C’ and ‘Concord’. Ten control cuttings of ‘Concord’ and ‘3309C’ were injected with an equal volume of sterile distilled water. From 24 to 32 weeks after inoculations, all P. chlamydospora-inoculated cuttings exhibited dark streaking of the vascular tissue extending 45 to 50 mm from the point of inoculation. The vascular streaking observed in inoculated plants was identical to symptoms observed in declining vines in the vineyard. Vascular streaking was absent in the controls. P. chlamydospora was isolated as a monoculture from regions of vascular streaking in 89% of inoculated cuttings. P. chlamydospora was not isolated from the water-treated controls. P. chlamydospora is widespread and readily isolated from declining grapevines in Pennsylvania, New York, and other national and international grape growing regions. To our knowledge, this is the first report of P. chlamydospora from the cultivars cited above in Pennsylvania and New York.

References: (1) M. Groenewald et al. Mycol. Res. 105:651, 2001. (2) Phytopathol. Mediterr. 39(1), 2000. (3) Phytopathol. Mediterr. 40, Supplement 2001.