Atmospheric Dynamics and Diversity of Alternaria and Fusarium in a Common Wheat (Triticum aestivum L.) Crop in NW Spain

Abstract

Abstract This study investigated the diversity of Alternaria and Fusarium species in atmospheric aerosols and plant tissue in a common wheat crop in NW Spain. The relationship between atmospheric fungal spore concentrations and weather conditions was analysed. To this end, non-viable and viable aerobiological monitoring methodologies were combined with isolates from plants showing symptoms of fungal infection. The isolates were identified by morphological characterisation and phylogenetic analysis of the 1‑alpha elongation factor (TEF-1α). Redundancy analysis was used to quantify the weight of delayed energy and water factors on spore dynamics. The global RDA model was significant, explaining 15.8% of the total variance. Alternaria was associated with wind speed and temperature, while Fusarium was linked to precipitation and humidity on the previous day. The coincidence of Alternaria species in the air and on plants was confirmed. However, while a high diversity of Fusarium species was identified in plant tissue, F . oxysporum predominated in the air. These findings underscore the need for future species-specific epidemiological models and the use of monitoring systems that allow for a comprehensive characterisation of the agroecosystem.