GENOME-WIDE IDENTIFICATION OF RAPIDLY EVOLVING GENES IN XYLELLA FASTIDIOSA: KEY ELEMENTS IN THE SYSTEMATIC IDENTIFICATION OF HOST STRAINS, AND IN THE SEARCH FOR PLANT-HOST PATHOGENICITY CANDIDATE GENES Project Leader:

INTRODUCTION Genomic research provides an extraordinarily powerful new tool for solving applied problems. It can be extremely effective at resolving evolutionary relationships and can be used to extend earlier work defining the interrelationships of the plant-host strains of Xylella fastidiosa (see Hendson et al. 2001). Similarly, it can provide effective methods for identifying these host strains. Unambiguous identification is of considerable importance for understanding the epidemiology of Pierce’s disease and the other plant diseases caused by this bacterium. This has been approached using a variety of DNA based methods (Banks et al. 1999; Hendson et al. 2001; Rodrigues et al. 2003; Meinhardt et al. 2003;); however, an effective methodology for identifying the plant-host strains, including when they are mixed together, has yet to be developed.