ENSURING SECURITY AND INTEGRITY OF VALUABLE BREEDING, RESEARCH, AND GERMPLASM COLLECTIONS

UCR and USDA scientists intend to be proactive in maintaining and protecting the citrus germplasm field collections. Until we have the technology and ability to eliminate HLB, the first step in protecting these resources is to identify infected trees and not allow them to provide a source of inoculum for adjacent trees. This systems approach could be implemented by regulators and/or growers to quickly detect potential sources of infection, and to determine the area around qPCR positive trees that need to be removed and thus, rapidly respond and potentially stay ahead of disease spread. Proactive protection of valuable breeding and research collections secures the health status of valuable germplasm and breeding lines and protects collections for future generations. ARS scientists will survey and assay trees of citrus/citrus relatives for the presence of HLB-associated pathogens using the USDA APHIS qPCR protocols and other primers including the newly reported RNR primers (J.C. Chen 2016). Each tree identified as a dog alert will be sampled extensively (200 petioles or shoots) for qPCR analysis, in addition to petioles and shoots, we will assay roots from a limited number of trees. As a control, a tree of the same variety from the USDA ARA screen house would be sampled and similarly analyzed.