甘肃省玉米籽粒中镰孢菌分离频率及伏马毒素含量监测
Occurrence of Fusarium species and fumonisins associated with maize kernels from Gansu Province

为了解甘肃省玉米籽粒中病原镰孢菌的种类以及籽粒中伏马毒素的含量,通过形态学特征、分子生物学鉴定和高效液相色谱法对2011-2012年间采自甘肃省5个地区的225份玉米籽粒样品进行了镰孢菌的分离、鉴定和伏马毒素含量的测定。结果表明,分离获得的516株镰孢菌经鉴定分别属于拟轮生镰孢菌Fusarium verticillioides、层出镰孢菌F. proliferatum、禾谷镰孢复合种F. graminearum species complex、亚粘团镰孢菌F. subglutinans、藤仓镰孢菌F. fujikuroi、木贼镰孢菌F. equiseti、尖镰孢菌F. oxysporum和F. temperatum;其中拟轮生镰孢菌分离频率最高,属甘肃省的优势病原菌。2011和2012年,镰孢菌的分离频率分别为31.0%和10.7%,禾谷镰孢复合种和拟轮生镰孢菌为当年的优势种群。同时,2011和2012年样品中伏马毒素的污染率分别为30.5%和50.9%,平均含量分别为175 μg/kg和224 μg/kg,但未发现伏马毒素含量超过欧盟委员会限量标准(4000 μg/kg)的样品。
To investigate the contamination of maize by Fusarium species and fumonisins, a total of 225 maize samples collected from five localities in Gansu Province during 2011 and 2012 were investigated for contamination with Fusarium species and fumonisins. Morphological and molecular methods were used to identify the Fusarium species, and fumonisins were quantified by high-performance liquid chromatography. The results showed that 516 Fusarium isolates were obtained and identified as F. verticillioides, F. poliferatum, F.graminearum species complex, F. subglutinans, F. fujikuroi, F. equiseti, F. oxysporum and F. temperatu, among which F. verticillioides was the dominant species. The average incidence of Fusarium species in 2011 was 31.0%, of which the F.graminearum species complex was the dominant species. In 2012, the isolation frequency of Fusarium was 10.7%, whereas F. verticillioides was the dominant species. Meanwhile, about 30.5% and 50.9% of maize samples were positive for fumonisins with the mean levels of 175 μg/kg and 224 μg/kg in 2011 and 2012, respectively. None of the samples was contaminated with fumonisins above the maximum level (4 000 μg/kg) set by the European Commission.