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Detection of “Candidatus Liberibacter solanacearum” in tomato on Norfolk Island, Australia

  • J. E. ThomasEmail author
  • A. D. W. Geering
  • G. Maynard
Article

Abstract

In June 2103, “Candidatus Liberibacter solanacearum” (CLso) (haplotype A) was detected in tomato plants (Solanum lycopersicon) with yellowing symptoms growing on Norfolk Island, non-self-governing external Australian Territory in the western Pacific Ocean. This appears to be only the second record, after New Zealand, of CLso haplotype A outside North America.

Keywords

Solanum lycopersicon haplotype A 
Candidatus Liberibacter solanacearum” (CLso) haplotypes A and B cause economically serious diseases in potato (zebra chip) and other solanaceous crops, including tomato and capsicum (bell pepper, chilli). The haplotype A of this pathogen was first reported from Mexico, and is now widely distributed elsewhere in Central America, as well as in the USA and New Zealand (Brown et al. 2016; Haapalainen 2014). Haplotypes C, D and E infect members of the Apiaceae and are found in Europe and the Mediterranean region (Alfaro-Fernández et al. 2017).Norfolk Island is a non-self-governing external Australian Territory, remotely located in the western Pacific Ocean almost equidistant between New Zealand and New Caledonia, and largely self-sufficient in fresh vegetable production. During quarantine surveys, small numbers of tomato plants (Solanum lycopersicon) with yellowing symptoms were noted in June 2013, and two samples (Accessions Q4978 and Q6005, Queensland Department of Agriculture and Fisheries Plant Virus and Bacteria Collection), both displaying interveinal chlorosis and upward leaf curling (Fig. 1), were collected in February 2014 for analysis. Simultaneously, small numbers of tomato-potato psyllid (Bactericera cockerelli), morphologically identified, were collected from yellow pan traps that were set for routine aphid surveillance (Anon. 2015). DNA extractions of plant tissue were done from freeze-dried tissue using the Bioline ISOLATE II Plant DNA kit. Both samples gave positive PCR amplifications with CLso-specific primers OI2C/OA2 (Liefting et al. 2009), with or without the generic nested primers Lib16S01F/ Lib16S01R (Beard et al. 2013), and also with the specific primers LP1611F/LP480R (Hansen et al. 2008). Sequencing of the former two PCR products from isolates Q4978 (GenBank MG589915) and Q6005 (GenBank MG589916) gave a consensus sequences of 1073 nt from the 16S rRNA gene. In BLASTn analysis, these were shown to share 100% identity with CLso isolate NZ08226 from tomato in New Zealand (EU834130) and nine other haplotype A CLso sequences from New Zealand and the USA. There were one to five nucleotide polymorphisms in this region compared with isolates of all other CLso haplotypes (B, C, D and E) examined.
Fig. 1

Field tomato plants infected with a CLso isolate Q4895 and b isolate Q6005

This is the first record of CLso from Norfolk Island, an Australian off-shore territory, and to our knowledge, the first record of CLso haplotype A from outside North America and New Zealand.

Notes

Acknowledgements

We thank Terri Cameron, Fiona Filardo and Vivian Rincon for technical assistance, the growers on Norfolk Island for access to materials, and the Plant Biosecurity Cooperative Research Centre and Australian Government Department of Agriculture for funding.

References

  1. Alfaro-Fernández A, Hernández-Llopis D, Font MI (2017) Haplotypes of ‘Candidatus Liberibacter solanacearum’ identified in Umbeliferous crops in Spain. Eur J Plant Pathol 149:127–131CrossRefGoogle Scholar
  2. Anon (2015) Norfolk Island quarantine survey 2012–2014, technical report. Australian Government Department of Agriculture, Canberra 193 ppGoogle Scholar
  3. Beard SS, Pitman AR, Kraberger S, Scott IAW (2013) SYBR green real-time quantitative PCR for the specific detection and quantification of ‘Candidatus Liberibacter solanacearum’ in field samples from New Zealand. Eur J Plant Pathol 136:203–215CrossRefGoogle Scholar
  4. Brown JK, Cicero JM, Fisher TW (2016) Psyllid-transmitted Candidatus Liberibacter species infecting citrus and solanaceous hosts. In: Brown JK (ed) Vector-mediated transmission of plant pathogens. APS Press, American Phytopathological Society, St Paul, pp 399–422CrossRefGoogle Scholar
  5. Haapalainen M (2014) Biology and epidemics of Candidatus Liberibacter species, psyllid-transmitted plant-pathogenic bacteria. Ann Appl Biol 165:172–198CrossRefGoogle Scholar
  6. Hansen AK, Trumble JT, Stouthamer R, Paine TD (2008) A new Huanglongbing species, “Candidatus Liberibacter psyllaurous,” found to infect tomato and potato, is vectored by the psyllid Bactericera cockerelli (Sulc). Appl Environ Microbiol 74:5862–5865CrossRefGoogle Scholar
  7. Liefting LW, Sutherland PW, Ward LI, Paice KL, Weir BS, Clover GRG (2009) A new ‘Candidatus Liberibacter’ species associated with diseases of solanaceous crops. Plant Dis 93:208–214CrossRefGoogle Scholar

Copyright information

© Australasian Plant Pathology Society Inc. 2018

Authors and Affiliations

  1. 1.QAAFI, The University of QueenslandBrisbaneAustralia
  2. 2.Department of Agriculture and Water ResourcesCanberraAustralia

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