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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #186596

Title: CHARACTERIZATION AND IDENTIFICATION OF PD RESISTANCE MECHANISMS: ANALYSIS OF XYLEM ANATOMICAL STRUCTURES AND OF NATURAL PRODUCTS IN XYLEM SAP AMONG VITIS

Author
item Lin, Hong
item Fritschi, Felix
item WALKER, ANDREW - UNIV OF CALIF-DAVIS

Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 10/1/2005
Publication Date: 12/5/2005
Citation: Lin, H., Fritschi, F.B., Walker, A. 2005. Characterization and Identification of Pierce's Disease Resistance Mechanisms: Analysis of Xylem Anatomical Structures and of Natural Products in Xylem Sap among Vitis. Proceedings of the 2005 Pierce's Disease Research Symposium. p. 39-42.

Interpretive Summary: Grapevine genotypes differ in their susceptibility/tolerance to Pierce’s disease (PD). This may be related to the concentration and presence or absence of chemical compounds in the xylem sap and/or due to structural features of the xylem. Here we report a three-pronged comparative approach investigating various grapevine species ranging in PD tolerance. In vitro assays of grapevine xylem sap revealed a broad range of Xf growth responses in both suspension growth and aggregated bacteria formation. The growth dynamics of Xf in stem tissues of greenhouse grown plants confirmed large differences in the sizes of Xf populations in susceptible and tolerant genotypes. Xylem vessel blockages account for differences in the number and kinds of occlusions among four different Vitis genotypes.

Technical Abstract: Grapevine genotypes differ in their susceptibility/tolerance to Pierce’s disease (PD). This may be related to the concentration and presence or absence of chemical compounds in the xylem sap and/or due to anatomical features of the xylem. Here we report on a three-pronged comparative approach investigating various grapevine species ranging in PD tolerance. Results from in vitro xylem sap assays indicate a broad range of Xf growth responses in both planktonic growth and biofilm formation. Investigations into Xf population dynamics in the stem tissues of greenhouse grown plants, confirm large differences in the size of Xf populations between susceptible and tolerant genotypes. Microscopic investigations into xylem vessel occlusions document the differences in occlusion percentages as well as the kinds of occlusions prevalent among four different Vitis genotypes.