Examining Rootstocks and Vitis Species for Non-host Resistance to Pierce’s Disease

AVF Proj. ID: 9721 / /Cat.: ,
Primary Investigator(s): Andrew Walker, Bruce Kirkpatrickby

Major Objectives:

  1. To screen the following commonly used rootstocks for the ability to be symptomless carriers of, or non-hosts to, Pierce’s Disease Bacteria (PDB): St. George, 5C, 5BB, 161-49, 3309C, 101-14, Schwarzmann, 44-53 Mgt, 11 OR, 1103P, Ramsey, Freedom, Harmony, 039-16.
  2. To screen selections from rupestris X rotundifolia seedling populations for resistance/non-host status to PDB.
  3. To screen 4 accessions of each of a range southern Vitis species for susceptibility to PD; the ability to act as non-disease expressing carriers of PDB; and the ability to be non-hosts to PDB.
  4. To test the possibilities of grafting vinifera scions onto an infected stock/trunk combination, and grafting to non-hosts identified above under greenhouse and Davis field conditions, in preparation for future field studies.

Summary:

We have prepared plant materials for PD screening, developed the inoculation system, have optimized the PD – PCR detection system, and have seedlings from a cross of Chardonnay X (rupestris X rotundifolia). These plant materials will be inoculated with PD during summer 1998 and results should be ready near the end of 1998.