Fungal Disease Causing Seed Rot in Production of Container Seedlings of Cryptomeria japonica

Abstract

In order to clarify the factors that restrict seed germination in production of containerized seedlings of Cryptomeria japonica, we studied the cause of un-germinating seed in container pots and the pathogenicity of fungi isolated from rotted seeds. Un-germinating seeds (95 seeds) at two months after seeding were categorized into healthy (30.5％), rotted by fungi (34.7％) and insect herbivory (8.4％), empty (21.1％) and sterile (5.3％). Fusarium oxysporum was isolated from rotted seeds and has pathogenicity of seed rot by our inoculation test. This suggests that seed rot by a fungal pathogen causes restricting seed germination in production of containerized seedlings.