The Parasitism of Red Pine and Other Forest Nursery Crops By Tylenchorhynchus Claytoni Steiner 1)

The tobacco stunt nematode, Tylenchorhynchus claytoni, was parasitic on but not pathogenic to, red pine seedlings (Pinus resinosa Ait.). Twelve other species of forest nursery seedlings were also found to be hosts for this nematode. No feeding or reproduction was found on red pine callus in vitro but the nematode fed and reproduced on red pine roots in agar culture. Little or no visible damage to roots was caused by nematode attack. However, the organization of root-cap cells was disrupted by the feeding activity of the nematode.