- Root-lesion nematodes (Pratylenchus spp.) infect many plant species including potato. For example P. penetrans has more than 350 hosts (Wikipedia). No potato resistance data known. The nematodes play a role in the Potato Early Dying Disease (PED) by increasing the damage caused by specific Verticillium dahliae isolates (MacGuidwin & Rouse, 1990; Botseas & Rowe, 1994).