RESUMEN
Objective To carry out a pilot investigation into fungus diversity in corn samples harvested from Keshan disease areas and obtain the information of dominant fungi,to predict possible secondary toxins in future study.Methods In Keshan disease areas (Heshui County and Zhengning County of Gansu Province,Yuanbao Town of Heilongjiang Province) and non-Keshan disease area (Harbin suburbs of Heilongjiang Province),5 samples of newly harvested corn from local plants were collected via the simple random sampling method,and the samples (n =20) were put in a sterile bags and sealed,numbered and transported to laboratory,placed in the incubator for cultivating mould fungi,cuhured for 2 weeks,and fungal DNA was extracted.The DNA samples were sent to Beijing Auwegene Technology Co Ltd for quality inspection,and sequencing analysis of fungal internal transcribed spacer 1 (ITS1) region was done using modern high-throughput DNA sequencing technique and MiSeq PE3000 platform,the rationality of sequencing data was analyzed through the rarefaction curve and the Shannon-Wiener curve trend to be gentle or not,and the true condition of the fungal community in the sample was tested by species composition Coverage ＞ 99％ or not,the difference in fungal community was studied between Keshan disease group and non-Keshan disease group based on the relative abundance of the fungal species in each group.Results A total of 513 869 high quality sequences were obtained,and 528 operational taxonomic unit (OTU) classifications were produced.The trend of rarefaction curve and Shannon-Wiener curve were gradually flattening,they showed that the sequences of the data were reasonable;and coverage ＞ 99％ showed that data could reflect the true situation of the fungal community.Analysis of species composition showed that there was a great overlap of fungal species between Keshan disease group and non-Keshan disease group,the relative abundance of the genus Wickerhamomyces,Candida and Aspergillus in Keshan disease group were higher than that of non-Keshan disease group.Conclusion Genus Wickerhamomyces,Candida and Aspergillus may be the dominant fungi associated with Keshan disease,it can be considered for secondary toxins studies.