Response of selected forest trees to Meloidogyne incognita infections

The reaction of seedlings of Acer negundo, Acer pseudoplatanus, Catalpa bignonioides, Celtis australis, Fraxinus excelsior, Juglans nigra, Juglans regia and Tilia cordata to Meloidogyne incognita host race 1 was evaluated in a glasshouse experiment. All the tested species were resistant with a GI (gall index) between 0 and 1.1. Only the roots of C. bignonioides were heavily infested by the nematode (G.I.= 3.25). Cross sections of M. incognita infested roots of the two most susceptible tree species tested (C. bignonioides and C. australis), had 4-6 multinucleate giant cells arranged araund the nematode body in the vascular cylinder. Abnormal and interrupted xylem elements were also observed in many sections.