APS Abstracts of Presentations

Occurrence of two new species of Togninia in California
A. ESKALEN (1), S. N. Rooney-Latham (1), L. L. Gallegos (1), W. D. Gubler (1)
(1) Dept. of Plant Pathology, University of California, Davis, CA, USA
Phytopathology 96:S33

Esca and Petri disease are two of the most destructive diseases of grapevines worldwide. In California, these diseases are caused by multiple species of Togninia (anamorph: Phaeoacremonium). The teleomorphs of Phaeoacremonium aleophilum, P. mortoniae, and P. viticola were recently confirmed as Togninia minima, T. fraxinopennsylvanica, and T. viticola, respectively. However, teleomorphs for other Phaeoacremonium species were unknown. In this study, grapevines showing esca symptoms were surveyed during summer and fall of 2004 and 2005. Samples were collected from native trees surrounding the vineyards, as well as from symptomatic grapevines. Perithecia of two new species of Togninia were found on the surfaces of old pruning wounds and in the cracks of cordons and trunks of Vitis vinifera cvs. Thompson seedless from Yolo Co., Riesling from Mendocino Co. and Chardonnay from Sonoma Co. Morphologically these perithecia resemble other Togninia spp. and when plated onto PDA-tet medium, ascospores formed colonies similar to other Phaeoacremonium spp. Molecular data confirmed these perithecia to be two new species of Togninia on grapevine, Togninia californica nom. prov. and Togninia davisiana nom. prov. Perithecia of Togninia davisiana were also observed on dead vascular tissue of declining ash trees (Fraxinus latifolia) in Yolo and Sonoma counties.

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