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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Liberibacters associated with orange jasmine in Brazil: incidence in urban areas and relatedness to citrus liberibacters

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Lopes, S. A. [1] ; Frare, G. F. [1] ; Camargo, L. E. A. [2] ; Wulff, N. A. [1] ; Teixeira, D. C. [1] ; Bassanezi, R. B. [1] ; Beattie, G. A. C. [3] ; Ayres, A. J. [1]
Total Authors: 8
[1] Fundo Def Citricultura, BR-14807040 Araraquara, SP - Brazil
[2] Univ Sao Paulo, Escola Super Agr Luiz Queiroz, BR-13418900 Piracicaba, SP - Brazil
[3] Univ Western Sydney, Ctr Plants & Environm, Penrith, NSW 1797 - Australia
Total Affiliations: 3
Document type: Journal article
Source: PLANT PATHOLOGY; v. 59, n. 6, p. 1044-1053, DEC 2010.
Web of Science Citations: 16

Two surveys (2005/2006 and 2009) were conducted in the state of Sao Paulo, Brazil, to investigate the incidence of `Candidatus Liberibacter asiaticus' and `Ca. L. americanus', two liberibacters associated with citrus huanglongbing (HLB) disease and both transmitted by Diaphorina citri, in orange jasmine (Murraya exotica), a widespread ornamental tree in cities and villages. The graft-transmissibility of the two species, and their DNA relatedness to citrus-associated liberibacters, were also investigated. Quantitative PCR was applied to PCR-positive orange jasmine and HLB-positive citrus growing in backyards and orchards to assess their inoculum source potentials. Liberibacters were detected in 91 of 786 sampled orange jasmine plants in 10 of 76 sampled locations. PCR-positive trees exhibited yellow shoots and/or dieback symptoms indistinguishable from those on PCR-negative trees. `Candidatus Liberibacter americanus' was more common in 2005/2006 (96 center dot 6%) and `Ca. L. asiaticus' in 2009 (84 center dot 8%). rplJ nucleotide sequences were identical within all populations of either species. Graft transmission succeeded only in homologous host combinations, including `Ca. L. americanus' (2/10) from/to orange jasmine and `Ca. L. americanus' (5/18) and `Ca. L. asiaticus' (5/9) from/to citrus. Symptoms were mild and developed less rapidly in orange jasmine than in citrus, probably as a result of lower liberibacter multiplication rates. Respective titres of `Ca. L. americanus' and `Ca. L. asiaticus' in orange jasmine averaged 4 center dot 3 and 3 center dot 0 log cells g-1 tissue, compared with 5 center dot 5 and 7 center dot 3 in citrus. The results indicate that orange jasmine does not favour liberibacter multiplication as much as citrus. However, its importance in HLB epidemics should not be underestimated as it is a preferred host of D. citri and is not under any strict tree-eradication programme or measures for insect control. (AU)

FAPESP's process: 05/00718-2 - Studies on the bacterium Candidatus Liberibacter spp., causal agent of citrus huanglongbing (ex-greening): diagnosis, biology and management
Grantee:Marcos Antonio Machado
Support type: Research Projects - Thematic Grants
FAPESP's process: 07/55013-9 - Molecular epidemiology and integrated management of Huanglongbing (asiaticus and americanus) in the State of São Paulo
Grantee:Armando Bergamin Filho
Support type: Research Projects - Thematic Grants