HortScience (2004) 39, 1025-1026

John Frampton and D.M. Benson (2004)
Phytophthora root rot mortality in Fraser fir seedlings
HortScience 39 (4), 1025-1026
Abstract: Seventeen-month-old seedlings from three fraser fir (Abies fraseri [Pursh] Poir.) seed sources (Mount Mitchell, Richland Balsam and Roan Mountain) were inoculated in an outdoor lath house with five genotypes of Phytophthora cinnamomi Rands. After 122 days, overall mortality was 90.5% with significant (p < 0.07) differences among seed sources. The Mount Mitchell source had lower mortality (83.2%) than the Roan Mountain source (95.8%), while the Richland Balsam source (92.5%) was intermediate. Mortality curves were developed using nonlinear regression (Richards' function). Due to a significant seed source x inoculum genotype interaction (p < 0.0001), equations were developed for each combination of seed source and inoculum genotype. Results suggest that while the overall frequency of resistance in fraser fir is low, seed sources differ in their frequency of resistance and that more than one resistance gene may be present. Survivors from this or similar inoculations could be cloned via grafting or rooted cuttings for further resistance testing and/or grafted into a Phytophthora-resistant fraser fir seed orchard.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): D. Michael Benson

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora cinnamomi	Fir (Abies)