Plectosphaerella rot of lettuce, coriander, and chervil caused by Plectosphaerella pauciseptata

摘要

Rot diseases of hydroponically cultured leaf lettuce, coriander, and chervil were found in Chiba Prefecture, Japan. Stems and petioles of the three diseased plants became brown or black with a soft rot, and vascular parts of the stems became discolored. Seemingly similar fungi were isolated from the diseased plants. Pathogenicity of these fungal isolates to each plant was demonstrated by inoculation tests. The fungi were identified as Plectosphaerella pauciseptata based on morphological and cultural characters. This identification was supported by phylogenetic analysis with rDNA ITS1-5.8S-ITS2 regions. The diseases were named Plectosphaerella rot (Plectosphaerella huhai-byo in Japanese) of lettuce, coriander, and chervil.