INFECTION OF PEA EPICOTYLS BY MYCOSPHAERELLA-PINODES

Infection of pea epicotyls by Mycosphaerella pinodes is described for the first time. The pathogen penetrated the cuticle with appressoria and infection pegs then grew through the outer wall of the epidermis, occasionally penetrating cells without causing necrosis. This phase of the disease, which is probably biotrophic, is followed by a typical necrotrophic phase involving progressive necrosis; the resulting macroscopic lesion often girdles the epicotyl. Epicotyl infection is particularly damaging and resistant cultivars are urgently needed.