Plant Pathology (2014) 63, 1078-1085

K.V. Plourde and L. Bernier (2014)
A rapid virulence assay for the Dutch elm disease fungus Ophiostoma novo-ulmi by inoculation of apple (Malus × domestica 'Golden Delicious') fruits
Plant Pathology 63 (5), 1078-1085
Abstract: Large-scale virulence tests using trees or saplings are expensive, time-consuming and require a considerable amount of space. The suitability of using 'Golden Delicious' apples as a rapid screen for identifying Ophiostoma novo-ulmi transformants with reduced virulence was thus evaluated. When a collection of O. novo-ulmi field isolates belonging to subspecies novo-ulmi or americana was inoculated to apples, members of subsp. novo-ulmi induced, on average, larger necrotic lesions than subsp. americana isolates. The size of the lesions on apples was not correlated with mycelial growth rate of isolates on nutrient agar. Insertional mutants from O. novo-ulmi subsp. novo-ulmi isolate H327 were inoculated to 'Golden Delicious' apples and Ulmus parvifolia × U. americana saplings in parallel experiments. Results clearly indicated that the O. novo-ulmi transformants included several exhibiting significantly altered levels of virulence. Variability among replicates within a treatment was reduced in apple inoculation data compared to elm sapling data. Overall, the 'Golden Delicious' apple assay was found to be an excellent means for rapidly assessing the virulence level of O. novo-ulmi isolates.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Louis Bernier

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ophiostoma novo-ulmi