1a. Objectives (from AD-416):
Identify and collect citrus germplasm in Florida threatened by HLB and citrus canker, begin preliminary therapy of germplasm in Florida, ship to the National Clonal Germplasm Repository for Citrus and Dates (NCGRCD), Riverside, CA for final therapy and pathogen indexing, return pathogen testing accession to Florida using “Citrus Passport protocols” following release from quarantine and keep a backup accession in the protected collection at NCGRCD.
1b. Approach (from AD-416):
A committee composed of members from the citrus breeding teams from University of Florida, USDA/ARS, Florida Budwood Program, NCGRCD, and members of the Florida Citrus Production Managers Association, Florida Nurserymans’ Association, and Florida Citrus Mutual would identify and prioritize elite germplasm vital for the short and long term survival of the Florida citrus industry and which is threatened by presence of exotic diseases. A technician, under the supervision of research scientists, would establish the plants and conduct the thermotherapy at ARS, Ft. Pierce, Florida. Personnel from ARS, Riverside and Florida CIP would conduct laboratory testing on plants at Ft. Pierce following the growout after thermotherapy. Once freedom from HLB and citrus canker is confirmed, budwood would be shipped under quarantine to the Repository, Riverside and some to Florida CIP, Gainesville, where shoot tip grafting followed by full biological indexing would be performed. Following release from quarantine, pathogen-tested budwood would be returned to Florida with a plant maintained in the Protected Collection at the Repository.
3. Progress Report:
This is the final report for this research. The purpose of this project is to preserve citrus germplasm in Florida that is threatened by loss due to huanglongbing (HLB) and citrus canker and relates to objective 1 of the parent project, "Strategically expand and improve collections of priority genetic resources of citrus and date palm and associated information". This research is in cooperation with the USDA ARS U.S. Horticultural Research Laboratory, Ft. Pierce, Florida, and the Florida Citrus Germplasm Introduction Program. This project provided for the testing and assistance with the therapy of the 66 accessions being held at Ft. Pierce for recovery. In collaboration with the Florida Citrus Germplasm Introduction Program, the accessions are beginning thermotherapy, which will be conducted for a 16 week time period. Following the thermotherapy, the accessions will be tested using laboratory methods for Candidatus Liberibacter asiaticus (Las) as well as other graft transmissible diseases of citrus, including viroids. Following the testing and depending on the results, the accessions will be forwarded to the USDA ARS Repository in Riverside for further clean up and testing before release from quarantine.