Influence of Temperature on the Virulence of Two Races of Meloidogyne chitwoodi on Wheat and Barley
AbstractRaces of the Columbia root-knot nematode, Meloidogyne chitzooodi, from Idaho (R1) and Utah (R2) suppressed (P 0.05) tillering of Dusty winter wheat, Fielder spring wheat, Luther winter barley, and Steptoe spring barley at 15-30 C. Nematode inoculum density was negatively correlated with tillering (r = -0.79). Inoculum densities of both nematode races were negatively correlated with heads per plant (r = -0.83), head length (r = -0.87), and head dry weight (r = 0.73) of Fielder spring wheat and Steptoe spring barley at all temperatures; the greatest growth restrictions occurred at Pi 20 eggs/cm³ soil. Both nematode races were most damaging at 25-30 C. Fielder spring wheat and Steptoe spring barley inoculated with R2 produced fewer heads than R1 when inoculated at 15 C, whereas the same cultivars inoculated with R1 produced fewer heads than R2 at 30 C. No differences were observed between root growth of winter and spring wheat or between winter and spring barley. Nematode reproduction was positively correlated to temperature (r = 0.87) and negatively correlated with inoculum density (r = -0.86). Reproductive rates were greatest with Pi = 2 eggs/cm³ soil at 25 C and lowest with Pi = 20 eggs/cm³ soil at 15 C for both nematode races. Key words: barley, Columbia root-knot nematode, damage potential, nematode, plant growth, reproductive index, root-gall rating, susceptibility, temperature, tillering, wheat.
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).