Climate-associated variation in fungal communities and mycotoxin contamination in corn silage across temperature zones of China

Mycotoxin contamination in silage is globally prevalent but regionally variable. In this study, fungal diversity and 53 mycotoxins were analysed in 120 corn silage samples collected from three temperature zones of China: subtropical (SZ), warm temperate (WTZ), and mid-temperate (MTZ), High-throughput sequencing revealed significant differences in fungal diversity and abundance among silages from different temperature zones, with Penicillium (9.0%), Diutina (8.4%), and Aspergillus (5.8%) among the dominant genera. Zearalenone, deoxynivalenol, beauvericin, fumonisins, and alternariol were the most frequently detected mycotoxins, with detection rates of 53% to 91%. Interestingly, although in WTZ silages fewer potentially toxigenic genera exhibited the highest relative abundances, these samples contained higher concentrations of multiple mycotoxins compared with SZ and MTZ silages. Network analysis indicated that fungal communities in WTZ silages displayed stronger interaction complexity. No strong linear relationship was detected between potentially toxigenic fungi (genus level) and mycotoxin concentrations, while non-toxigenic fungi showed complex associations with mycotoxins, suggesting that microbial interactions under specific climatic conditions may contribute to mycotoxin accumulation. These findings highlight the importance of fungal community interactions in predicting and managing mycotoxin contamination under different climatic conditions.