Identification and Prevalence Mechanism of Dominant Pathogens of Peanut Pod Rot in Henan, China

Peanut pod rot (PPR) is a major constraint to peanut production in Henan Province, China. To clarify the pathogen composition and the prevalence mechanism of dominant species, 710 fungal isolates were obtained from symptomatic pods across ten regions from 2021 to 2023. PPR in Henan was caused by Fusarium spp. (85.92%), Rhizoctonia spp. (6.20%), Alternaria spp. (5.35%), and Pythium spp. (2.54%). Based on the morphological characters and phylogenetic analyses, the dominant Fusarium population was further classified into eight distinct species: F. solani, F. oxysporum, F. proliferatum, F. neocosmosporiellum, F. commune, F. arcuatisporum, F. sulawesiense, and F. verticillioides. Among these, F. solani (50.56%) was the dominant species of PPR in Henan from 2021 to 2023, followed by F. oxysporum (17.32%). Comparative assays revealed that F. solani exhibited superior mycelial growth and sporulation under continuous darkness, caused severe disease without requiring wounding, displayed stronger pathogenicity across multiple peanut cultivars, and showed lower sensitivity to several commonly used fungicides, whereas no significant difference in carbon or nitrogen utilization breadth was observed between the two species. These traits collectively explain the predominance of F. solani in Henan PPR and provide a scientific basis for developing region-specific management strategies.