Parasitism of Ectomycorrhizae of Pine by Lance Nematode

Abstract Ectomycorrhizae were formed in aseptic culture on roots of Pinus taeda seedlings with Pisolithus tinctorius and in open pot culture on roots of Pinus echinata seedlings with Thelephora terrestris . Mycorrhizal and nonmycorrhizal roots on intact seedlings were inoculated with either 100 lance nematodes, Hoplolaimus galeatus , per individual glass cylinder or 6,000 per pot in a growth room equipped with electronic filters to remove airborne fungal spores. Irrespective of pine host, mycorrhizal fungus, or method used to form ectomycorrhizae, both male and female nematodes penetrated the fungal mantle of mycorrhizae. The nematodes readily parasitized cortical cells of roots morphologically altered by the fungal symbionts. Penetration of ectomycorrhizae by nematodes may allow entry of other root pathogens and also may lessen or destroy the beneficial physiological activity of ectomycorrhizae. Forest Sci. 17:31-34.