棉铃虫为害与拟轮生镰孢侵染对玉米穗腐病发生及玉米籽粒中伏马毒素污染水平的影响

Effects of infestation by Helicoverpa armigera together with Fusarium verticillioides on the severity of maize ear rot and the contamination level of fumonisin in kernels

本研究以‘浚单20’为供试玉米品种,以棉铃虫为供试昆虫,以拟轮生镰孢为供试病原菌,分别进行单独及复合处理,以明确棉铃虫和拟轮生镰孢单独处理和复合处理对玉米穗腐病发病程度及籽粒中伏马毒素污染水平的影响。结果表明,2011年和2012年均以棉铃虫与拟轮生镰孢侵染复合处理对穗腐病发病程度及籽粒中伏马毒素污染水平的影响最大,穗腐病平均病级分别为0.68±0.05和1.08±0.19;单独接种棉铃虫,2011年和2012年的穗腐病平均病级分别为0.31±0.05和0.71±0.06;单独接种拟轮生镰孢,穗腐病平均病级分别为0.24±0.03和1.05±0.29。复合处理的籽粒中伏马毒素污染水平,2011年和2012年分别为(0.85±0.56)mg/kg和(2.36±0.98)mg/kg;单独接种棉铃虫处理分别为(0.17±0.12)mg/kg和(0.01±0.002)mg/kg;单独接种拟轮生镰孢处理分别为(0.10±0.03)mg/kg和(1.14±0.62)mg/kg。相同处理条件下,降水量大和相对湿度高的气候条件更有利于穗腐病的发生及籽粒中伏马毒素的积累。

The effects of co-infestation by Helicoverpa armigera and Fusarium verticillioides on the severity of maize ear rot and the contamination level of fumonisins in kernels were investigated.The maize variety ‘Xundan 20’was used,and the maize ears were inoculated with H .armigera ,F .verticillioides ,and H .armigera together with F .verticillioides ,respectively.The results of 2011 and 2012 showed that the co-inoculation of H .armigera and F .verticillioides significantly increased the severity of maize ear rot and the content of fumonisins in kernels. Average disease levels of maize ear rot in the treatment with both H .armigera and F .verticillioides were 0.68± 0.05 and 1.08±0.19 for 2011 and 2012,respectively,while the average disease levels of maize ear rot were 0.31 ±0.05 and 0.71±0.06 for the treatment with H .armigera only,and 0.24±0.03 and 1.05±0.29 for the treat-ment with F .verticillioides only.Meanwhile,the content of fumonisins in kernels treated with both H .armigera and F .verticillioides were （0.85±0.56）mg/kg and （2.36±0.98）mg/kg for 2011 and 2012,respectively.For the treatment with H .armigera only,it was （0.17±0.12）mg/kg and （0.01±0.002）mg/kg,respectively,and （0.10 ±0.03）mg/kg and （1.14±0.62）mg/kg after treated with F .verticillioides only,respectively.Under the same treatment conditions,the climatic conditions of high rainfall and high relative humidity were in favor of the sever-ity of maize ear rot and the accumulation of fumonisins in kernels.