Forest Pathology (2013) 43, 407-414

N.J. Brazee (2013)
Phylogenetic and differentiation analysis of the trunk rot pathogen Fomitiporia tsugina in North America
Forest Pathology 43 (5), 407-414
Abstract: Fomitiporia hartigii s.l. is an important trunk rot pathogen of conifers throughout the Northern Hemisphere. In North America, this pathogen primarily attacks Tsuga, but is also found on Abies, Picea and Pseudotsuga. Previous research showed that isolates of F. hartigii from North America represent a distinct phylogenetic species, known as F. tsugina. However, that conclusion is based on limited data. To better understand the phylogenetic relationships of F. tsugina in North America, a phylogenetic analysis was performed using three loci (internal transcribed spacer, nuclear large subunit and tef1) with 23 isolates originating from the northern United States, Canada and central Europe. North American isolates formed a monophyletic group with significant statistical support, confirming previous reports that F. tsugina represents a unique phylogenetic species, distinct from European F. hartigii s.s. Population subdivision between isolates of F. tsugina from eastern (Massachusetts, Michigan, New Hampshire, New York and Wisconsin) and western (British Columbia, Colorado, Oregon and Washington) North America was investigated. Tests of gene flow and genetic differentiation based on region of origin detected significant variation (FST = 0.761; KST = 0.625, p < 0.01), suggesting gene flow between the two populations may be limited. Neutrality tests revealed significant, negative departures from the standard neutral model, which could indicate that a purifying or stabilizing selection has maintained low levels of polymorphisms in the population, perhaps favouring an advantageous phenotype. Further studies are required to better understand the occurrence of F. tsugina on Abies and Picea in boreal forests outside the natural range of Tsuga.
(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): Nicholas J. Brazee

Research topic(s) for pests/diseases/weeds:
molecular biology - genes
identification/taxonomy

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Fomitiporia punctata		U.S.A. (NW)
	Fomitiporia punctata		U.S.A. (NE)
	Fomitiporia punctata		Canada (west)