Seedling rot of garland chrysanthemum caused by Gibellulopsis chrysanthemi and ecological characters of the causal fungus

A new disease found on garland chrysanthemum in Osaka, Japan in 2009 and its causal agent were identified and characterized. Light brown spots first appeared on lower leaves of seedlings, and the leaves blighted or rotted. A fungus isolated from diseased plants, described recently as Gibellulopsis chrysanthemi, was demonstrated to reproduce the natural symptoms in inoculation tests. Sufficiently long, moist periods after inoculation promoted the infection even after lengthy dry periods. The pathogen also caused the disease on chrysanthemum and lettuce, but not on seven other vegetables. The fungus caused the disease after 6 months of dry storage. The disease was termed seedling rot (“nae-fuhai-byo” in Japanese).