Assessment of wheat grain quality in China during harvest and storage using a mycobiome approach

Fungal activity in stored wheat grains can lead to quality deterioration, especially in the form of mycotoxin accumulation. This study proposes an approach for assessing wheat quality by analyzing the wheat grain mycobiome using high-throughput sequencing technology. Wheat grain samples were collected from China's major production areas during both the harvest and storage stages to investigate the temporal and spatial trends in fungal distribution. The results revealed significant differences in the fungal diversity and communities during different stages of wheat processing, with a more complex fungal co-occurrence network in stored wheat than in harvested wheat. Aspergillus was the keystone taxon in the network of the stored wheat mycobiome. It was assigned to the "Unspecified_saprotroph" group and was found to contribute significantly to the differences in fungal community structure between harvested and stored wheat. We also constructed a Random Forest (RF) model to predict the freshness of the wheat grains. The RF model exhibited a strong ability to correctly determine the wheat grain stage based on the mycobiome present on the surface of the wheat grains, achieving a 98.28% accuracy rate, which confirmed the potential of mycobiome analysis for assessing wheat grain quality. This study provides a new perspective for assessing grain quality and sanitation security, which is significant for the supervision of food safety.