Seasonal discrepancy of airborne fungal diversity and community structure in Lentinula edodes factory

Abstract

ABSTRACT Understanding the composition and community of airborne mycobiota associated with fungal diseases was critical for mushroom production and disease control. In this study, we first investigated airborne fungi concentrations in different function areas of a Chinese shiitake factory. Then, high-throughput sequencing was employed to characterise the airborne fungal compositions and communities of this factory during high and low incidence seasons of shiitake artificial log rot disease (SLRD). The lowest concentration of culturable airborne fungi was observed in spawn-running greenhouse (250–450 CFU/m3), while the airborne fungi concentrations in cultivation greenhouses were up to 7,000–8,500 CFU/m3. The airborne fungal communities across distinct function areas showed convergence. The four major mushroom contaminants, Trichoderma, Penicillium, Cladosporium, and Aspergillus were the stable core fungi. Seasonal shifts in compositions, abundances, and communities of airborne fungi were systematically analysed and found to be associated with SLRD. Compared with the SLRD low incidence season, the airborne fungal communities were rich but uneven in the SLRD high incidence season, in which Trichoderma was dominant. Further analysis indicated that the favourable temperature and humidity caused the proliferation of Trichoderma and then affected the fungal communities, which presented an SLRD-seasonal variation. SLRD incidence could be significantly reduced by reasonably increasing the ambient temperature. For the first time, we comprehensively characterised the dynamics of airborne fungal communities across the SLRD occurrence in the shiitake factory. Findings here also provided valuable information for fungal exposures in the mushroom industry.