First report of a new subgroup 16SrIX-E (‘Candidatus Phytoplasma phoenicium’-related) phytoplasma associated with juniper witches’ broom disease in Oregon, USA
Article first published online: 2 NOV 2010
© 2010 The Authors. Plant Pathology © 2010 BSPP
Volume 59, Issue 6, page 1161, December 2010
How to Cite
Davis, R. E., Dally, E. L., Zhao, Y., Lee, I.-M., Jomantiene, R., Detweiler, A. J. and Putnam, M. L. (2010), First report of a new subgroup 16SrIX-E (‘Candidatus Phytoplasma phoenicium’-related) phytoplasma associated with juniper witches’ broom disease in Oregon, USA. Plant Pathology, 59: 1161. doi: 10.1111/j.1365-3059.2010.02294.x
- Issue published online: 2 NOV 2010
- Article first published online: 2 NOV 2010
- Accepted 11 May 2010 at http://www.bspp.org.uk/ndr where figures relating to this paper can be viewed.
Western juniper (Juniperus occidentalis) is a native tree indigenous to parts of Oregon, Washington, Idaho, Nevada and California (USA). The tree has increased in density since settlement of these areas, raising concern over loss of understory plants, decreased wildlife habitat and increased soil erosion. A newly recognized disease, juniper witches’ broom (JunWB), affecting at least 1% of trees in central Oregon, is characterized by abnormal proliferation of shoots, reduced size of leaves, shortened internodes, and growths having a ball-like appearance. DNA was extracted from leaf samples from ball-like growths and used as template in polymerase chain reactions primed by primer pair P1/P7 (Deng & Hiruki, 1991; Schneider et al., 1995). DNA fragments of 1·8 kb amplified from two samples were sequenced and the sequences deposited in GenBank (Accession Nos. GQ925918 and GQ925919). RFLP patterns of 16S rDNA, observed as virtual patterns using iPhyClassifier (Zhao et al., 2009), indicated that JunWB phytoplasma represents a new subgroup lineage, designated 16SrIX-E. 16S rDNA sequence similarity confirmed that JunWB is a ‘Ca. Phytoplasma phoenicium’-related phytoplasma.
JunWB is one of three phytoplasmas found thus far to infect gymnosperms and is the only phytoplasma known to infect Juniperus sp. Occurrence of three distinct phytoplasmas, JunWB phytoplasma (this study), a group 16SrIII strain, and ‘Ca. Phytoplasma pini’ (Schneider et al., 2005), in gymnosperms of two different families (Pinaceae and Cupressaceae, Division Coniferae) in Europe and North America, suggests that phytoplasmal infection of conifers may be more common than previously envisioned.
- 1991. Amplification of 16S rRNA genes from culturable and non-culturable mollicutes. Journal of Microbiological Methods 14, 53–61. , ,
- 1995. Phylogenetic classification of plant pathogenic mycoplasma-like organisms or phytoplasmas. In: RazinS, TullyJG, eds. Molecular and Diagnostic Procedures in Mycoplasmology. New York, NY, USA: Academic Press, Vol. 2, 369–80. , , , ,
- 2005. ‘Candidatus Phytoplasma pini’, a novel taxon from Pinus silvestris and Pinus halepensis. International Journal of Systematic and Evolutionary Microbiology 55, 303–7. , , , , , ,
- 2009. Construction of an interactive online phytoplasma classification tool, iPhyClassifier, and its application in analysis of the peach X-disease phytoplasma group (16SrIII). International Journal of Systematic and Evolutionary Microbiology 59, 2582–93. , , , , , ,