Impacts of multiple trophic and climatic factors on the growth kinetics of Fusarium spp. associated with wheat head blight

Abstract Climatic and nutritional factors significantly influence the behavior of pathogenic agents by limiting their growth and mycotoxin production. Understanding these factors aids in predicting and managing mycotoxigenic risks. In this context, this study was conducted to characterize the ecophysiological profile of the most virulent Fusarium isolates identified in the region, including 6 F. clavum, 2 F. avenaceum , 5 F. acuminatum , 2 F. culmorum, 1 F. tricinctum, 1 F. microconidium , and 1 F. solani , using an in vitro one-factor-at-a-time (OFAT) approach. The results indicated that nutritional requirements, including culture media, carbon and nitrogen sources, and the C:N ratio, pH, salinity, temperature, and relative humidity, were the primary factors influencing mycelial growth. The current study found that the most effective conditions for enhancing the growth of the examined isolates were Czapek Dox Agar medium at 25 °C, 95% relative humidity, pH 7, and a salinity of 2.5 g. L⁻ 1 , or by using cellulose as the carbon source, peptone as the nitrogen source, and a C:N ratio of 10:1. Significant diversity was observed among the isolates and Fusarium species; different strains of the same species responded differently to climatic and trophic factors, while different species showed similar responses. These parameters effectively grouped the isolates into two clusters using hierarchical clustering.