Macrophomina phaseolina causing charcoal rot on soybean (Glycine max) in Taiwan

Plants of soybean (Glycine max) exhibiting charcoal rot were observed in Wandan Township of Pingtung County in Taiwan, in Sep 2019. The diseased plants displayed symptoms of root rot and leaf blight, as well as black microsclerotia were visible in the roots and lower stem of the infected plants. Based on cultural, morphological and DNA data, the pathogen was identified as Macrophomina phaseolina. Pathogenicity of M. phaseolina on soybean was confirmed by Koch's postulates. This fungus has been proposed to produces the mycotoxin (-)-botryodiplodin, and therefore, may produce a potential impact on food and feed safety in Taiwan.