Pathogenic and mycotoxin-producing fungi from cereals
State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences
The significant factors diminishing the value and yield of cereals were phytopathogens and mycotoxin-producing organisms, especially fungi. Recently we investigated the diseased cereal crops (maize, rice, wheat) from 250 locations, covering the major cereal-growing regions in China. In this paper we report our partial results on Fusarium. We obtained a total of 2 020 Fusarium strains from 315 diseased samples, which were identified to 43 species, including eight novel species. A world checklist of cereal-associated Fusarium species is provided, with 39 and 52 new records updated for the world and China, respectively. Notably, 56 % of samples collected were observed to have co-infections of more than one Fusarium species. In the isolation and analysis of mycotoxin producing fungi from fresh harvesting cereals, our work revealed that the Aspergillus flavus and A. parasiticus were the major AFT producing fungi. The North East region exhibited a much lower risk of AFT contamination due to its lower prevalence of toxigenic fungi. In the storage stage study, we observed that the relative abundances of Aspergillus increased over storage time, but decreased with the increase of stored vertical depth within the warehouse. Temperature was the most important factor associated with differences in microbial communities across storage periods. The potential mycotoxin producing fungal species A. flavus and A. niger exhibited significantly higher abundances in rice storage in South West compared to those of North East. Our recent progress on applying meta-data in origin trace and quarantine inspection of cereals were also presented in this paper.