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Witch’s broom phytoplasma infecting Echinacea pallida in Australia
Citation
Pearce, TL and Scott, JB and Pethybridge, SJ, Witch's broom phytoplasma infecting Echinacea pallida in Australia, 2011 APS-IPPC Joint Meeting Abstracts of Presentations, 6-10 August, Honolulu, Hawaii, pp. S139. (2011) [Conference Extract]
 | PDF (Pearce, T. L., Scott, J. B., and Pethybridge, S. J. 2011. Witch’s broom phytoplasma infecting Echinacea pallida in Australia. Phytopathology 101:S139) Pending copyright assessment - Request a copy 3Mb |
Abstract
Purple coneflower (Echinacea pallida), is commercially cultivated in
Australia for its medicinal properties. In 2005, coneflower fields in Tasmania,
Australia began exhibiting symptoms typical of phytoplasma infection,
including virescence, phyllody and chlorosis. Surveys of fields in 2011
indicated the presence of symptoms within one field only. Disease distribution
in this field was assessed by hierarchical sampling, incorporating 10 spatially
referenced transects. Along each transect, 20 individual plants were assessed
at 1 m intervals for the proportion of symptomatic flower heads. Overall,
incidence of infected plants was estimated at 32%, while the mean percentage
of symptomatic flower heads was 12%. Spatial analysis indicated a random
distribution of symptoms across the field. Phytoplasma infection was
confirmed by DNA sequencing of a 1.2 kb region of the 16S RNA gene,
obtained by amplifying total DNA extractions from symptomatic coneflower
tissue. Individual sequences shared greater than 99% homology with
‘Candidatus Phytoplasma australasiae’. Comparison of virtual restriction
fragment profiles from the same genetic region confirmed that the pathogen
belonged to the Witch’s Broom (16SrII-D) group of phytoplasmas. All
previous reports of phytoplasma infection of coneflower have indicated Aster
Yellows (16SrI-C) group phytoplasmas as the causal agents.
Item Details
| Item Type: | Conference Extract |
|---|---|
| Keywords: | phytplasma, Echinacea |
| Research Division: | Biological Sciences |
| Research Group: | Plant biology |
| Research Field: | Plant pathology |
| Objective Division: | Plant Production and Plant Primary Products |
| Objective Group: | Horticultural crops |
| Objective Field: | Horticultural crops not elsewhere classified |
| UTAS Author: | Pearce, TL (Dr Tamieka Pearce) |
| UTAS Author: | Scott, JB (Dr Jason Scott) |
| UTAS Author: | Pethybridge, SJ (Dr Sarah Pethybridge) |
| ID Code: | 100313 |
| Year Published: | 2011 |
| Deposited By: | Tasmanian Institute of Agriculture |
| Deposited On: | 2015-05-11 |
| Last Modified: | 2015-05-11 |
| Downloads: | 0 |
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