Project Number: 5352-22000-016-08
Project Type: Specific Cooperative Agreement

Start Date: Aug 30, 2007
End Date: Aug 31, 2009

Objective:
Objective of this research is to determine if the potato psyllid induces zebra chip (ZC) potato disease by transmitting pathogens or just delivering toxins to potato plants.

Approach:
Psyllids and ZC symptomatic plants and tubers will be collected and tested for suspected pathogens using PCR and ELISA; pathogens to be tested will include phytoplasmas, viruses, and bacteria. ZC plants will be grafted onto healthy tomato and potato plants and observed for symptoms. If ZC symptoms do appear on grafted plants, this would support the idea that a pathogen is involved in the disease. The ZC-grafted symptomatic plants will be tested for putative ZC pathogens. To investigate potential transmission of toxins by the psyllid, selected numbers of nymphs and adults will be allowed to feed on healthy plants briefly, during selected periods of time, and permanently. The plants will be maintained and observed for ZC symptom expression or remission. Psyllids will be dissected and their salivary glands extracted. The salivary glands will be ground and the crude extract injected into healthy plants; the plants will be maintained and observed for ZC symptoms. Moreover, the gland extracts will be analyzed for proteins using various chemical separation methods. The separated protein fractions will be tested as above and those that produce ZC symptoms will be analyzed to identify individual components responsible for the disease transmission.