Seed Rot, a New Disease of Beech Tree Caused by Neonectria ramulariae (anamorph: Cylindrocarpon obtusiusculum)

During a survey of seed diseases of Fagus crenata, a new fungal disease of the seeds was found with high frequency in Akita, northern Japan. Main symptoms are often expressed as browning of the cracked parts from exposed cotyledons and complete loss of viability of infected seeds. Reddish perithecia and whitish yellow sporodochia were occasionally observed symptoms and determined that they were anamorph–telemorph relationship on the basis of both cultural observations. Inoculation studies confirmed that this fungus was the cause of seed rot. The fungus is morphologically identical with Neonectria ramulariae (anamorph: Cylindrocarpon obtusiusculum) that is well known as the soil-born fungi around the world. Sequences between the authentic isolate of Neo. ramulariae (CBS 151.29) and the pathogenic fungus based on ITS, LSU and tub showed high similarity. Thus, ‘seed rot’, the new disease of beech seeds caused by Neo. ramulariae (anamorph: Cyl. obtusiusculum) was proposed in this study.