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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Publications at this Location » Publication #283334
Title: Association of ‘Candidatus Liberibacter asiaticus’, the causal agent of citrus huanglongbing in Murraya paniculata and Diaphorina citri in Thailand

Author
item JANTASOM, AROM - Kasetsart University
item Duan, Ping
item PUTTAMUK, THAMRONGJET - Kasetsart University
item ZHANG, SHOUAN - University Of Florida
item THAVEECHAI, NIPHONE - Kasetsart University

Submitted to: Thai Journal of Agricultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2012
Publication Date: 8/1/2012
Citation: Jantasom, A., Duan, Y., Puttamuk, T., Zhang, S., Thaveechai, N. 2012. Association of ‘Candidatus Liberibacter asiaticus’, the causal agent of citrus huanglongbing in Murraya paniculata and Diaphorina citri in Thailand. Thai Journal of Agricultural Science. 45(3):161-170.

Interpretive Summary: The ornamental citrus relative, Murraya paniculata, known as orange jasmine is a preferred host for the Asian citrus psyllid (ACP). The ACP transmits the citrus disease Huanglongbing (HLB) associated with three phloem specific bacteria. The most common of these bacteria is ‘Candidatus Liberibacter asiaticus’ (Las). Orange jasmine samples and ACP found on the plants from ten diverse geographical regions of Thailand were collected and DNA was extracted to test for the presence Las. The data showed that the levels of infection by Las varied in both the plant and the ACPs found throughout Thailand. The infection levels varied among regions but were low in the plant and its associated ACP. The results suggest that urban plantings of orange jasmine may serve as a minor source of Las inoculum. This is a first association of the infection frequency of Las in orange jasmine and its associated ACPs in Thailand. These plantings could be a potential HLB disease source for citrus in Thailand.

Technical Abstract: Orange jasmine, Murraya paniculata, is a preferred alternative host for the Asian citrus psyllid, the primary vector of citrus Huanglongbing (HLB) disease caused by ‘Candidatus Liberibacter asiaticus’ (Las). M. paniculata plant samples and psyllids on the Murraya plants from ten diverse geographical regions of Thailand were collected and extracted DNA to evaluate the presence and titers of Las by conventional PCR and two different methods of real-time PCR. The data showed variation of Las levels both in M. paniculata and psyllids in Thailand. Different titers among individual psyllid sample were observed in each province of Thailand. Samples from Chanthaburi province displayed the average titer level of HLB pathogen with Ct value of 21.85. The highest titer level was found in sample from Nakhon Pathom province with Ct values of 16.12. The titer of Las is therefore low in M. paniculata and associated psyllids. The results suggest that urban planting of M. paniculata may serve as a minor source of Las inoculum. Our work provides a first association of the infection frequency of Las on psyllid vector from and M. paniculata in Thailand which could be a potential source of inoculum for citrus HLB in Thailand.