Multi-Gene Identification and Pathogenicity Analysis of Sugarcane Pokkah Boeng Disease Pathogens in Yunnan, China

Pokkah boeng disease (PBD), a fungal disease of sugarcane, is caused by multiple species of Fusarium. To identify the pathogens causing PBD in Yunnan Province, China, we collected 87 leaf samples with typical PBD symptoms from the sugarcane-growing areas of Puer, Honghe, and Lincang, from which eight strains (FS1–FS8) were isolated and purified. The identities of the eight isolates were determined based on a combination of morphological observations and molecular analyses, using which we identified five Fusarium species as the causal agents of PBD in Yunnan, namely, F. incarnatum, F. andiyazi, F. sacchari, F. proliferatum, and F. verticillioides. Among these, F. incarnatum is a newly recorded species in Yunnan. Pathogenicity tests revealed that all five Fusarium species can infect sugarcane and cause PBD symptoms, with the severity of pathogenicity, ranked from strong to weak, being ordered as follows: F. proliferatum > F. andiyazi > F. incarnatum > F. verticillioides > F. sacchari. In this study, we identified the species and established the pathogenicity of the causal agents of PBD in Yunnan Province. Our findings will provide a scientific basis for the prevention and control of this disease.