COMPARISON OF VISUAL ASSESSMENT AND POLYMERASE CHAIN REACTION ASSAY TESTING TO ESTIMATE THE INCIDENCE OF THE HUANGLONGBING PATHOGEN IN COMMERCIAL FLORIDA CITRUS

摘要

Huanglongbing (HL6 = citrus greening) is one of the most serious diseases of citrus worldwide. The disease is caused by species of bacteria in the genus Candidatus Liberi-bacter and was discovered for the first time in the United states in Florida inAugust, 2005. To date, the Asian form of HLB, caused by Candidatus Liberibacter asiaticus, is the only FORM OF HLB that has been found in Florida. Molecular detec-tion rotocols are available for the detection of HLB but due to the uneven distribution ofthe bacterium in trees, the serolog-ical variability of the pathogen, and perceived limitations of testing methodology, molecular testing generally has been limited to the confirmation of visible infections and not for de-tection of infections in non-symptomatic plants. In this study, visual surveys were compared to the testing of trees with a real time polymerase chain reaction-based assay (real-time PCR). The incidence of infection based on real-time PCR test-ing may be up to two times the incidenceof infection estimat-ed by visible symptoms alone.