conference schedule and program with abstracts - Horticulture ...

P-103
The biological characteristics of Xylella fastidiosa in xylem fluid from resistant and
susceptible grapevines
X. Shi* 1 , Z. Liang 2 , J. Bi 3 , J.G. Morse 3 , D.A. Cooksey 4
1 Plant Pathology Department, NYSAES, Cornell University, Geneva, New York, USA; 2
Department of Horticulture, Cornell University, Ithaca, New York, USA; 3 Entomology
Department, University of California, Riverside, California, USA; 4 Plant Pathology Department,
University of California, Riverside, California, USA
*Corresponding author: shixy2100@yahoo.com
Xylella fastidiosa (Xf) is a fastidious and xylem-limited Gram-negative bacterium that causes
Pierce’s disease (PD) on grapevine. It was investigated that while grapevine V. vinifera is
susceptible to the PD strain of Xf, V. champinii and V. smalliana are tolerant or resistant to the
PD strain. The biological characteristics of Xf PD strain were investigated by examining the in
vitro effect of pure xylem fluid from resistant and susceptible grapevines on Xf multiplication,
aggregation, and attachment. The aggregations of large clumps were formed in pure xylem fluid
from susceptible grapevine, whereas small clumps were observed in resistance grapevines xylem
fluid. Microarrays are being applied for analysis of differential gene expression files of Xf PD
strain in xylem fluids from different grapevines. Xylem fluid is being analyzed to determine the
chemical compounds or elements that control the virulence of Xf. The motility of Xf in
differential xylem fluids of grapevines is being observed within micro-channels.
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