Interaction of root‐lesion nematodes, Pratylenchus thornei and P. crenatus, with the fungus Thielaviopsis basicola and a grey sterile fungus on roots of pea (Pisum sativum)

Abstract

Pratylenchus thornei invaded excised pea roots in agar in greater numbers and penetrated the cortex more deeply than P. crenatus. Both species fed on the roots ectoparasitically and displaced root cells into the surrounding medium. The cytoplasm of cortical cells near cither nematode became granulated, with enlarged vacuoles and nuclei. P. thornei also caused these responses in the endodermis. Infection of the root surface with a grey sterile fungus inhibited invasion by P. crenatus and P. thornei. Infection by Thielaviopsis basicola inhibited P. thornei invasion but encouraged penetration by P. crenatus and the hyphae were found deeper in the cortex when P. crenatus was present.