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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Publications at this Location » Publication #315446

Title: Interactive Effects of Water Stress and Neofusicoccum Parvum on Botryosphaeria Dieback of Grapevines

item LAWRENCE, DANIEL - University Of California
item Galarneau, Erin
item TRAVADON, RENAUD - University Of California
item Baumgartner, Kendra

Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2015
Publication Date: 11/1/2015
Citation: Lawrence, D., Galarneau, E.R., Travadon, R., Baumgartner, K. 2015. Interactive effects of water stress and Neofusicoccum parvum on Botryosphaeria dieback of grapevines. American Phytopathological Society Abstracts. 576-P.

Interpretive Summary:

Technical Abstract: The relationship between vascular pathogens and water stress is an important topic in California agriculture, given successive years of drought and restrictions on water use. We examined the interactive effects of water stress and Neofusicoccum parvum on severity of Botryosphaeria dieback of grapevines. Cabernet Sauvignon plants were inoculated with N. parvum after wounding; control plants were wounded and inoculated with PDB. After 2 weeks, water stress was imposed on half of the inoculated and control plants. Water usage was estimated weekly for non-stressed plants to provide 20% of this volume for stressed plants. Leaf water potential was monitored weekly with a pressure chamber to maintain potentials of > -8 bars for non-stressed and < -13 bars for stressed plants. Leaves were collected for RNA extraction 2 weeks before imposing water stress (2 weeks post-inoculation, 2 WPI), and at 8 and 12 WPI. At 12 WPI, lengths of stem lesions were measured and used to determine the effect of the pathogen and/or water stress on the vascular tissue. Inoculated plants under water stress had the greatest lesion lengths, relative to other treatments. To examine the specificity of the host response to the pathogen, water-stressed plants were used to screen 13 grapevine genes that have been shown to be differentially regulated in leaves in response to N. parvum. Some markers were specific to infection, whereas others cross-reacted with water stress in non-inoculated plants.