Project Number: 5302-22000-008-22
Project Type: Specific Cooperative Agreement

Start Date: Jun 01, 2005
End Date: Dec 31, 2008

Objective:
1. Evaluate diversity of Spiroplasma citri strains in citrus and brassicaceous hosts in California. 2. Identify S. citri strains with novel plant host ranges. 3. Assess role of leafhopper vectors including but not necessarily limited to Circulifer tenellus and Scaphytopius spp. in the epidemiology of citrus stubborn disease in California.

Approach:
1. Collect and establish S. citri strains from various areas, crops, and weed hosts in California. 2. Evaluate S. citri strain diversity by Rep.-PCR (using standard BOX and ERIC primers as well as novel primers developed to spiroplasma bacterial sequences), protein profiles, serology, cell and colony morphology, plasmid content, and host range. 3. Create phylogenetic trees based on S. citri sequences. 4. Test transmission efficiency by key leafhopper species. 5. Collect feral leafhoppers from infected field plants and test inoculativity in laboratory. Formerly 5302-22000-005-27S (10/05)& 5302-22000-007-15S (5/07).