Species Identification and Fungicide Sensitivity of Fusarium spp. Causing Peanut Root Rot in Henan, China

Peanut Root Rot (PRR) is a devastating disease that significantly limits peanut production worldwide. Although PRR has been frequently reported in Henan Province of China, the predominant <i>Fusarium</i> species and their sensitivity to different fungicides remain unclear. Between 2021 and 2023, we surveyed 81 peanut fields across 17 cities in Henan Province, China, to assess PRR prevalence and <i>Fusarium</i> species distribution. A total of 1131 <i>Fusarium</i> isolates were identified based on the morphological characters and phylogenetic analyses and classified into 11 recognized <i>Fusarium</i> species: <i>F. solani</i> (56.06%), <i>F. oxysporum</i> (20.87%), <i>F. neocosmosporiellum</i> (13.62%), <i>F. proliferatum</i> (4.69%), <i>F. acuminatum</i> (1.33%), <i>F. commune</i> (1.15%), <i>F. graminearum</i> (1.06%), <i>F. pseudograminearum</i> (0.35%), <i>F. ipomoeae</i> (0.35%), <i>F. lacertarum</i> (0.26%), and <i>F. armeniacum</i> (0.26%). Pathogenicity assessments showed that all 11 <i>Fusarium</i> species were capable of causing PRR, with <i>F. solani</i> exhibiting the highest isolation frequency and widespread distribution in all areas. Furthermore, the four <i>Fusarium</i> species (<i>F. solani</i>, <i>F. oxysporum</i>, <i>F. neocosmosporiellum</i>, and <i>F. proliferatum</i>) were highly sensitive to the six fungicides, including prochloraz (EC₅₀ values of 0.02 ± 0.00~0.06 ± 0.01 mg/L), pydiflumetofen (EC₅₀ values of 0.31 ± 0.07~0.67 ± 0.06 mg/L), tetramycin (EC₅₀ values of 0.11 ± 0.02~0.58 ± 0.08 mg/L), tebuconazole (EC₅₀ values of 0.26 ± 0.07~0.65 ± 0.10 mg/L), prothioconazole (EC₅₀ values of 1.14 ± 0.16~3.15 ± 0.81 mg/L), and difenoconazole (EC₅₀ values of 0.62 ± 0.12~3.58 ± 0.76 mg/L). This comprehensive study is the first systematic documentation on the prevalence, virulence, and fungicide sensitivity of PRR pathogens in Henan Province. The findings of the current study will provide a theoretical basis for the effective management of peanut root rot in Henan, China.