Taxonomic reassessment of the ray blight pathogen of pyrethrum in Australia

Vaghefi, N. and Pethybridge, S. J. and Ford, R. and Nicolas, M. E. and Crous, P. W. and Taylor, P. W. (2012) Taxonomic reassessment of the ray blight pathogen of pyrethrum in Australia. In: 2012 American Phytopathological Society Annual Meeting (APS 2012), 4-8 Aug 2012, Providence, Rhode Island, USA.

Abstract

Pyrethrum (Tanacetum cinerariifolium) is a perennial plant grown commercially for the extraction of the natural insecticide, pyrethrin, from its flowers. The Australian pyrethrum industry supplies more than 60% of the world’s pyrethrin requirements. Ray blight is a major threat to pyrethrum production in Australia, capable of causing complete yield loss. The disease appeared in Tasmanian fields in 1995 and the causal agent was identified as Phoma ligulicola var. inoxydabilis. Further studies on the morphology and biology of the fungus revealed some divergence from the published descriptors of the type strains, which cast some doubts on its taxonomy. The aim of this study was to reassess the taxonomy of the pathogen. Australian and overseas isolates from pyrethrum and other Asteraceae were compared to the type strains of the ray blight pathogen based on morphological characters and multi gene phylogeny of LSU, ITS, TUB, ACT and EF sequences. Results showed that ray blight of Asteraceae is caused by multiple species of the genus Stagonosporopsis. The type strains of the ray blight pathogen, previously known as var. inoxydabilis and var. ligulicola, were elevated to species S. inoxydabilis and S. chrysanthemi, respectively. The pathogen associated with ray blight of pyrethrum in Australia was re-classified as a new species, S. tanaceti. This finding highlights the need for further studies into the biology of the pathogen since it may have quarantine and epidemiological implications for the industry.


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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Speech)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 06 Nov 2017 03:15
Last Modified: 22 Jun 2018 04:47
Uncontrolled Keywords: Pyrethrum; diseases; ray blight
Fields of Research : 07 Agricultural and Veterinary Sciences > 0706 Horticultural Production > 070603 Horticultural Crop Protection (Pests, Diseases and Weeds)
06 Biological Sciences > 0607 Plant Biology > 060704 Plant Pathology
06 Biological Sciences > 0605 Microbiology > 060505 Mycology
URI: http://eprints.usq.edu.au/id/eprint/33104

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