Paraphoma chlamydocopiosa sp. nov. and Paraphoma pye sp. nov., two new species associated with leaf and crown infection of pyrethrum |
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Authors: | A Moslemi P K Ades P W Crous T Groom J B Scott M E Nicolas P W J Taylor |
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Affiliation: | 1. Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, Victoria, Australia;2. School of Ecosystem and Forest Sciences, University of Melbourne, Melbourne, Victoria, Australia;3. Westerdijk Fungal Biodiversity Institute, Utrecht, Netherlands;4. Botanical Resources Australia Pty Ltd, Ulverstone, Tasmania, Australia;5. Tasmanian Institute of Agriculture, University of Tasmania – Cradle Coast Campus, Burnie, Tasmania, Australia |
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Abstract: | Two new pathogens of pyrethrum, described as Paraphoma chlamydocopiosa and Paraphoma pye, isolated from necrotic leaf lesions on pyrethrum plants in northern Tasmania, Australia, were identified using morphological characters, phylogenetic analysis of the internal transcribed spacer (ITS), elongation factor 1‐α (EF1‐α) and β‐tubulin (TUB) genes, and pathogenicity bioassays. Bootstrap support in the combined and individual gene region phylogenetic trees supported the two species that were significantly different from the closely related P. chrysanthemicola and P. vinacea. Morphological characteristics also supported the two new species, with conidia of P. chlamydocopiosa being considerably longer and wider than either P. chrysanthemicola or P. vinacea, and P. pye being distinct in forming bilocular pycnidia. Glasshouse pathogenicity tests based on root dip inoculation resulted in P. chlamydocopiosa and P. pye infecting the crown and upper root tissues of pyrethrum plants, and significant reduction in biomass 2 months after inoculation. Both of these Paraphoma species caused leaf lesions during in vitro and in vivo bioassays 2 weeks after foliar spray inoculation. Although P. chlamydocopiosa and P. pye were shown to be crown rot pathogens, they were also commonly isolated from leaves of diseased plants in pyrethrum fields of northern Tasmania. |
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Keywords: | bilocular pycnidia longer conidia
Paraphoma chlamydocopiosa
Paraphoma pye
pathogenicity phylogenetic analysis |
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