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Poster: Diseases of Plants: New & Emerging Diseases


Survey for Grapevine Pinot gris virus infecting Grapevine in the Foundation Plant Services Vineyards at the University of California, Davis
M. AL RWAHNIH (1), N. Westrick (2), D. Golino (2), A. Rowhani (2) (1) University of California, Davis, U.S.A.; (2) University of California, Davis, U.S.A.

Grapevine Pinot gris virus (GPGV) is a new member of the genus Trichovirus in the family Betaflexiviridae. The virus was first discovered by high-throughput sequencing from an Italian Pinot gris grapevine (Vitis vinifera) showing chlorotic mottling, leaf deformation and stunting symptoms. Since then, GPGV has been reported in symptomatic and asymptomatic plants of other cultivars in many countries. Recent transmission studies indicated that the eriophyid mite Colomerus vitus (Pagenstecher) is the suspected vector. This vector infests grapevine wherever they are grown and it has been reported in California. To address the possible presence and prevalence of GPGV in the collections of the Foundation Plant Services (FPS, University of California, Davis), 2,014 vines from the collection were screened including 23 vines of Pinot gris. Among all the vines tested, only one asymptomatic vine cv. Touriga Nacional was positive for GPGV. This grapevine cultivar has been imported from Portugal in 1981and planted in the FPS collection in 2001. This is believed to be the first reported detection of GPGV in the U.S. Twenty samples in close proximity to the GPGV-positive vine were also collected and tested. These vines were all tested negative for GPGV. As a leading source of orchard and vineyard planting stock in the U.S., in addition to being a central component of the Grape Clean Plant Network, these negative results indicate that FPS stock is not a major source of GPGV.