Forest Pathology (2016) 46, 206-214

I. Matsiakh, H. Solheim, N.E. Nagy, A.M. Hietala and V. Kramarets (2016)
Tissue-specific DNA levels and hyphal growth patterns of Hymenoscyphus fraxineus in stems of naturally infected Fraxinus excelsior saplings
Forest Pathology 46 (3), 206-214
Abstract: Ten saplings of European ash (Fraxinus excelsior L.) naturally infected by the invasive ash dieback pathogen Hymenoscyphus fraxineus were collected in Ukraine and Norway and examined for bark necrosis and extension of discoloration in sapwood and pith in a stem region. Tissue-specific colonization profiles were determined by spatial analyses of symptomatic and visually healthy stem tissues using a H. fraxineus-specific qPCR assay and light microscopy. Our data suggest that hyphal growth in the starch-rich perimedullary pith is of particular importance for both axial and radial spread of H. fraxineus, but that most of its biomass accumulates in sapwood parenchyma. The study confirms the results from earlier work and presents new information that refines the current stem invasion model.
(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): Iryna Matsiakh, Ari M. Hietala

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.
	Hymenoscyphus fraxineus	Ash (Fraxinus)	Norway
	Hymenoscyphus fraxineus	Ash (Fraxinus)	Ukraine