Bisifusarium delphinoides: a causal agent of stalk rot in Pennisetum × sinese Roxb

Pennisetum × sinese Roxb is a critical forage crop widely cultivated in Yunnan Province, China. During a 2023 field survey in Lijiang City, Yunnan, five Pennisetum × sinese Roxb plants exhibiting lodging and disintegration of internal stalk tissues were examined to determine the causal agent. Through isolation, morphological characterization and sequence-based identification, Bisifusarium delphinoides (Schroers, Summerb., O'Donnell & Lampr.) was isolated and confirmed as the causative pathogen from the symptomatic Pennisetum × sinese Roxb plants. Pathogenicity tests and the fulfillment of Koch's postulates demonstrated that B. delphinoides is the agent responsible for the observed stalk rot disease in Pennisetum × sinese Roxb. To the best of our knowledge, this is the first report of B. delphinoides causing stalk rot in Pennisetum × sinese Roxb. The emergence of this disease poses a serious threat to the production of this important forage crop in the region.