中文摘要：黄曲霉毒素是诱发癌症、免疫抑制的霉菌毒素，在赞比亚频繁污染包括玉米和花生在内的重要主食。在非洲，好几种Flavi组曲霉被认为是黄曲霉毒素污染的病原菌。然而，在赞比亚尚不明确与黄曲霉毒素污染相关的曲霉菌群。赞比亚的大多数耕地尚未耕作，而作物曲霉菌群就可能源于非耕作土壤。但是，尚未探索作物与非耕地土壤中曲霉种群的关系。由于在赞比亚以外，类似的对真菌种群的表征提供了预防黄曲霉毒素的措施，所以本研究旨在提高对耕地和非耕地土壤及作物中真菌群落的了解。研究表明，表征赞比亚农业生态系统黄曲霉毒素污染的致病因子，为改良真菌群落结构、降低黄曲霉毒素生产潜力提供了支撑。
外文摘要：Aflatoxins are cancer-causing, immuno-suppressive mycotoxins that frequently contaminate important staples in Zambia including maize and groundnut. Several species within Aspergillus section Flavi have been implicated as causal agents of aflatoxin contamination in Africa. However, Aspergillus populations associated with aflatoxin contamination in Zambia have not been adequately detailed. Most of Zambia's arable land is non-cultivated and Aspergillus communities in crops may originate in non-cultivated soil. However, relationships between Aspergillus populations on crops and those resident in non-cultivated soils have not been explored. Because characterization of similar fungal populations outside of Zambia have resulted in strategies to prevent aflatoxins, the current study sought to improve understanding of fungal communities in cultivated and non-cultivated soils and in crops. Crops (n=412) and soils from cultivated (n=160) and non-cultivated land (n=60) were assayed for Aspergillus section Flavi from 2012 to 2016. The L-strain morphotype of Aspergillus flavus and A. parasiticus were dominant on maize and groundnut (60% and 42% of Aspergillus section Flavi, respectively). Incidences of A. flavus L-morphotype were negatively correlated with aflatoxin in groundnut (log y=2.4990935-0.09966x, R2=0.79, P=0.001) but not in maize. Incidences of A. parasiticus partially explained groundnut aflatoxin concentrations in all agroecologies and maize aflatoxin in agroecology III (log y=0.1956034+0.510379x, R2=0.57, P<0.001) supporting A. parasiticus as the dominant etiologic agent of aflatoxin contamination in Zambia. Communities in both non-cultivated and cultivated soils were dominated by A. parasiticus (69% and 58%, respectively). Aspergillus parasiticus from cultivated and non-cultivated land produced statistically similar concentrations of aflatoxins. Aflatoxin-producers causing contamination of crops in Zambia may be native and, originate from non-cultivated areas, and not be introduced with non-native crops such as maize and groundnut. Non-cultivated land may be an important reservoir from which aflatoxin-producers are repeatedly introduced to cultivated areas. The potential of atoxigenic members of the A. flavus-L morphotype for management of aflatoxin in Zambia is also suggested. Characterization of the causal agents of aflatoxin contamination in agroecologies across Zambia gives support for modifying fungal community structure to reduce the aflatoxin-producing potential.
外文关键词：Aspergillus；Flavi；Aflatoxin；Maize；Groundnuts；Zambia
作者：Kachapulula, PW；Akello, J；Bandyopadhyay, R；Cotty, PJ
作者单位：Univ Arizona
期刊名称：INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY
期刊影响因子：3.445
出版年份：2017
出版刊次：11
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