Canadian Journal of Plant Pathology (2011) 33, 202-209

Glen R. Stanosz, Lori M. Trummer, Jennifer K. Rohrs-Richey, Denise R. Smith, Gerard C. Adams and James J. Worrall (2011)
Response of Alnus tenuifolia to inoculation with Valsa melanodiscus
Canadian Journal of Plant Pathology 33 (2), 202-209
Abstract: Valsa melanodiscus (anamorph Cytospora umbrina) has been associated with cankers, dieback, and death of alder (Alnus) stems in western North America. To determine the ability of this fungus to induce these symptoms, the responses of thinleaf alder (Alnus tenuifolia) stems to inoculation with V. melanodiscus were studied in field locations in Alaska and on plants in a greenhouse. In the field, woody stems were wounded to expose both inner bark and sapwood and inoculated in early May 2007 or September 2007 by placing a colonized agar plug over the wound. Sunken, elongated cankers that developed on inoculated stems in the field closely resembled those attributed to natural infection of thinleaf alders by V. melanodiscus. In contrast, wounded control stems exhibited strong callus production and wound closure. In the greenhouse, actively growing lateral shoots were inoculated by placing a colonized agar plug over a fresh leaf scar. Inoculation in the greenhouse resulted in development of cankers, and severity of symptoms was affected by the maturity of the shoot at the point of inoculation. These results support the conclusion that V. melanodiscus is a cause of alder dieback in western North America.
(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): Glen R. Stanosz, Denise R. Smith, James J. Worrall

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.
	Cytospora umbrina	Alder (Alnus)	U.S.A. (Alaska)