Link to home

Low Incidence of ‘Candidatus Liberibacter asiaticus’ in Murraya paniculata and Associated Diaphorina citri

June 2012 , Volume 96 , Number  6
Pages  827 - 832

Abigail J. Walter and David G. Hall, Subtropical Insects Research Unit, and Yong Ping Duan, Subtropical Plant Pathology Research Unit, United States Department of Agriculture–Agricultural Research Service, U.S. Horticultural Research Laboratory, Fort Pierce, FL 34945

Go to article:
Accepted for publication 12 December 2011.

Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. ‘Candidatus Liberibacter asiaticus’ is the prevalent species of three HLB-associated Liberibacter spp., which is vectored by the psyllid Diaphorina citri. The vector and the bacteria have host plants outside the genus Citrus, and these plants have the potential to affect disease epidemiology within citrus groves. Murraya paniculata could be especially problematic because it is a popular ornamental plant and a host of both psyllid and bacteria. We conducted a year-long survey of eight urban plantings of M. paniculata in east-central Florida to characterize ‘Ca. L. asiaticus’ infection rates in plants and associated psyllids. Using sensitive quantitative polymerase chain reaction (qPCR) primers targeting two prophage genes of ‘Ca. L. asiaticus’, we found infection to be extremely low: less than 1% of psyllids and 1.8% of plants. With qPCR primers targeting ‘Ca. L. asiaticus’ 16S rDNA, none of the plants and only one psyllid were ‘Ca. L. asiaticus’-positive. Therefore, the titer of ‘Ca. L. asiaticus’ is low in M. paniculata and associated psyllids. These results suggest that urban plantings of M. paniculata may serve as a minor source of ‘Ca. L. asiaticus’ inoculum.

This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 2012.