Few sprouts were found from stolons of Glycyrrhiza glabra cultivated in Osaka Pref. in 2020. The stolon pieces were almost rotted with browning in vessels and bore white molds under moist condition. A fungus was often isolated from the damaged stolon pieces. Inoculations with a representative isolate to G. glabra not only reproduced the stolon rot but caused base rot and blight on healthy seedlings of G. glabra and Glycyrrhiza uralensis. The same fungus as the inoculum was re-isolated from the diseased seedlings. The isolate formed a colony with white to pale yellow aerial mycelia with ocher color on reverse side of PDA culture. Its micro-conidiophores were straight or slightly curved, smooth, hyaline, septate, sometimes branched, elongated obclavate to cylindrical, with monophialides on the apices. Microconidia were hyaline, 1 or 2-celled, smooth ellipsoid to boat-shaped. Macroconidia were 3-5 septate, hyaline, smooth, falcate. Chlamydospores were hyaline, thick walled, 1 or 2-celled, sub-spherical to ellipsoid, smooth or verrucose. The isolate was identified as Fusarium vanettenii based on the morphology, rDNA-ITS and Histone H3 sequences. We propose a name, base and stolon rot (‘kabugare byo’ in Japanese), for the new disease.
