<I>Aphelenchoides hylurgi</I> as a Carrier of White, Hypovirulent <I>Cryphonectria parasitica</I> and its Possible Role in Hypovirulence Spread on Blight-Controlled American Chestnut Trees
AbstractIndividual nematodes were isolated from American chestnut blight-controlled cankers to determine if they were carriers of biocontrol (hypovirulent) isolates of the chestnut blight fungus, Cryphonectria parasitica. These hypovirulent isolates have a white fungal colony phenotype due to infection by the virus CHV1. Of 1,620 individual Aphelenchoides hylurgi isolated, 29.4% carried propagules of the blight fungus and 8.2% of these yielded white hypovirulent isolates. In attraction and movement tests in Petri plates, A. hylurgi moved 2 cm over 24 hr to mycelial discs of white hypovirulent C. parasitica and pigmented C. parasitica strains in nearly equal numbers. After 2 days of nematode movement to fungal colonies on agar in Petri plates and 21 days of nematode growth, large numbers of A. hylurgi were extracted from both white hypovirulent and pigmented C. parasitica strain colonies. Lower numbers of A. hylurgi were extracted from excised young American chestnut blight cankers that were inoculated with A. hylurgi and incubated for 22 days. A. hylurgi inoculated on the surface of an excised American chestnut canker moved within 24 hr to the small, sporebearing C. parasitica reproductive structures (stromata) on the canker surface. The results indicate that A. hylurgi may play a role in the spread of hypovirulence on American chestnut trees.
Copyright and Permissions
All material published by the Society of Nematologists (SON), except for papers prepared by United States and Canadian government employees, is copyrighted and protected under the U.S. copyright law. Under the Copyright Act of 1976, the term of copyright for materials registered by an organization is 75 years from the date first published. Before publishing any manuscript, SON requires that authors transfer full and complete ownership of any copyright to SON by signing a JON Page Charge/Copyright Form (.pdf). SON then registers the copyright. Subsequent use of published materials requires written permission from the SON and may be obtained by contacting the current Editor-in-Chief and state where and how the material will be used.
The author warrants that the article is an original work not published elsewhere in whole or in part, except in abstract form, and that the author has full power to make this grant. If portions of the article have been published previously, then the author warrants that permission has been obtained from the copyright holder and the author will submit a copy of the permission release with this copyright transfer form.
SON shall claim no proprietary right other than copyright. Authors and coauthors retain the right to revise, adapt, modify, or otherwise use all or part of the article in future works of the author(s), such as press releases, lectures, and reviews, provided that all such use is for the personal noncommercial benefit of the author(s). All patent rights are retained by the author(s).