Field Fungal Diversity in Freshly Harvested Japonica Rice

Rice is a major food crop in China and Japonica rice production in Heilongjiang Province ranks No.1 in total annual rice production in the country. Rice is prone to invasion by fungi and mycotoxinsproduced by the fungi are proven to be serious threats to human health. The objective of the present study was to investigate fungal diversity of freshly harvested rice in the four main cultivation regions of Heilongjiang Province in order to find the difference of dominant fungi among the four regions. Through high throughput sequencing we detected Ascomycotaaccounts for absolute dominant phylum; Dothideomycetes, Sordariomycetes, Tremellomycetes, Microbotryomycetes, and Eurotiomyceteswere dominant classes; Capnodiales, Hypocreales, and Pleosporaleswere the main orders; Cladosporiaceae, Pleosporaceae, Nectriaceae, Clavicipitaceae, Tremellaceae, Phaeosphaeriaceae, Trimorphomycetaceae, Sporidiobolaceae, Bionectriaceae,and Trichocomaceaewere major family;Cladosporium, Epicoccum, Fusarium, and Alternariawere the most abundant phylotypes at genus level; Epicoccumnigrum, Gibberellazeae, and Fusariumproliferatumwere the dominant fungal species. Great fungal diversity was observed in the rice samples harvested in the four major Japonica rice-growing regions in Heilongjiang province. However, no significant difference in diversity was observed among the four regions, likely due to the relatively close geographical proximity leading to very similar climatic conditions. Since some of the fungal species produce mycotoxins, it is necessary to take precautions to ensure the rice is stored under safe conditions to prevent the production of mycotoxins. This is the first report on investigation of field fungal diversity in freshly harvested Japonica rice in Heilongjiang Province in China.