Root rot disease of Polygala crotalarioides caused by Fusarium oxysporum in China

Abstract

Polygala crotalarioides, a plant highly valued for its medicinal properties, suffered a severe root rot outbreak in a medicinal plant planting base in Yunnan Province, China, from 2022 to 2023. The affected plants exhibited typical root rot symptoms, beginning with localized browning of roots and rhizomes, progressing to basal petiole rot, and ultimately leading to leaf death and rhizome decay. This outbreak resulted in substantial economic losses, with an incidence rate of 50–60%. Fusarium oxysporum was identified as the causative agent through multigene phylogenetic analysis (using tub2, tef1-α, and rpb2) and morphological characterization, further confirmed by in vitro artificial inoculation. Our study is the first to report F. oxysporum as the cause of root rot in P. crotalarioides and provides valuable information for the prevention and control of this damaging disease.