1a. Objectives (from AD-416):
Assess the ability of potato varieties with low reducing sugar content to tolerate ZC disease and to reduce the amount of post-fry darkening observed in ZC-infected tubers.
1b. Approach (from AD-416):
Conduct controlled insect exposure experiments under field cage conditions in WA to: 1) assess the ability of potato varieties with low reducing sugar content to tolerate ZC disease and to reduce the amount of post-fry darkening observed in ZC-infected tubers; 2) use potato lines with low sugar content developed by Simplot through the invertase silencing technique to salvage mildly ZC-infected tubers and make them usable, especially following late season Lso-infection; and 3) assess whether these potato lines produced through invertase silencing can minimize ZC development during storage.
3. Progress Report:
The work summarized in this progress report relates to objective number 3 in the Project Plan for 018-00D: 3. Develop economical, sustainable, and ecologically sound methods for control of aphids, wireworms, and secondary pests of potatoes; and objective number 2 in the Project Plan for 020-00D: 2. Develop bio-intensive methods to manage insect vectors of zebra chip and purple top diseases. All commercial potato varieties currently available in U.S. are susceptible to zebra chip, a new and serious disease of potato, and vigorous pest control programs that rely heavily on use of conventional insecticides targeted against the potato psyllid vector are currently the only means to manage the disease. Development and identification of potato varieties with resistance to or tolerance of zebra chip through traditional breeding and/or genetic engineering are crucial to development of effective and sustainable management strategies for this disease. Research at ARS Wapato location assessed the ability of potato varieties with low reducing sugar content developed by J.R. Simplot through genetic engineering to: 1) tolerate zebra chip disease and reduce the amount of post-fry darkening observed in zebra chip-infected tubers, 2) salvage mildly zebra chip-infected tubers and make them usable, especially following late season Liberibacter-infection, and 3) minimize zebra chip development during storage. The study is currently underway but preliminary results suggest that these genetically engineered varieties with low sugar content could indeed withstand zebra chip and reduce the amount of darkening produced in diseased-infected tubers. Information from this research will help potato growers and processors to quickly minimize losses due to zebra chip by adopting these potato varieties with low reducing sugars.