蚜虫危害与玉米果穗镰孢菌组成及毒素污染关系分析

Analysis of the Relationship Between Aphid-Damage and Fusarium Composition,Mycotoxin Pollution on Maize Ears

【目的】明确玉米蚜虫危害与玉米穗腐病发生及籽粒中真菌毒素污染水平的关系,为建立完善的玉米穗腐病综合防治体系及探寻主要镰孢菌毒素的有效控制技术提供参考。【方法】通过组织分离和分子生物学方法对2021年在吉林省46个市(县)采集的105份蚜虫危害的玉米果穗上的蚜虫、苞叶和籽粒进行病原菌的分离鉴定,统计蚜虫、苞叶和籽粒分离获得镰孢菌的种类和数量,分别计算不同镰孢菌在每种样品上的分离频率,以及不同样品组合分离相同镰孢菌数量在蚜虫危害样品中的占比,分析病原菌在吉林省不同区域的分布情况及蚜虫、苞叶和籽粒携带镰孢菌种类的相关性;利用超高效液相色谱-串联质谱法(UPLC-MS/MS)检测无蚜虫危害籽粒和蚜虫危害籽粒中镰孢菌毒素的种类和含量,统计伏马毒素(fumonisin,FB)、脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)和玉米赤霉烯酮(zearalenone,ZEA)超标样品的检出率,分析蚜虫危害对病原菌在籽粒中分泌毒素的影响。【结果】对105个蚜虫危害果穗进行镰孢菌检测,发现蚜虫带菌率为57.14%,苞叶和籽粒带菌率分别为81.90%和82.86%。经过单孢分离纯化共获得1 394株镰孢菌,共16个致病镰孢种,其中在蚜虫、苞叶和籽粒上分离到镰孢种数量分别为8、13和12个。蚜虫、苞叶和籽粒上分离到的优势镰孢均为拟轮枝镰孢(Fusarium verticillioides)和层出镰孢(F.proliferatum)。新知镰孢(F.andiyazi)、变红镰孢(F.incarnatum)和温带镰孢(F.temperatum)在吉林省玉米籽粒上首次检出。蚜虫危害玉米果穗的毒素检出率均高于无蚜虫危害玉米果穗,出现毒素含量超标的玉米样品均为有蚜虫聚集危害的果穗。在检出毒素的果穗上绝大多数能检测到产生相应毒素的菌株。【结论】蚜虫、苞叶和籽粒上分离到的优势镰孢菌均为拟轮枝镰孢和层出镰孢;同一果穗上蚜虫、苞叶和籽粒分离到的主要镰孢菌种类一致;蚜虫危害显著增加了玉米籽粒毒素的积累,且毒素类型与检出镰孢菌种类高度相关。

【Objective】The objective of this study is to clarify the relationship between maize aphids damage and the occurrence of maize ear rot and the level of mycotoxin pollution in maize kernels,and to provide a reference for establishing a comprehensive control system of maize ear rot and exploring the effective control technology of main Fusarium toxins.【Method】The 105aphid-damaged maize ears were collected from 46 cities and counties in Jilin Province in 2021.Pathogenic fungi were isolated and identified using tissue isolation and molecular biology methods for aphids,bracts and kernels.The isolation frequency of different Fusarium species on each sample and the proportion of the same Fusarium number isolated from different sample combinations in aphid-infested samples were calculated.The distribution of pathogens in different regions of Jilin Province and the correlation between the species of Fusarium carried by aphids,bracts and kernels were analyzed.Additionally,ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was employed to determine the presence of Fusarium toxin species and content of maize kernels with and without aphid infestation.The detection rate of fumonisin(FB),deoxynivalenol(DON) and zearalenone(ZEA) in samples exceeding the standard was calculated,and the effect of aphid damage on the toxin secretion of Fusarium in kernels was analyzed.【Result】Aphids,bracts and kernels from 105 ears were tested for the Fusarium,the infection rate of aphids was 57.14%,and that of bracts and kernels was 81.90% and 82.86%,respectively.A total of 1 394 Fusarium strains,including 16 pathogenic Fusarium species,were obtained through single spore isolation and purification.Among them,8,13 and 12 Fusarium species were isolated from aphids,bracts and kernels,respectively.The dominant Fusarium species on aphids,bracts and kernels were F.verticillioides and F.proliferatum.Three species including F.andiyazi,F.incarnatum and F.temperatum were detected for the first time on maize kernels in Jilin Province.The results of mycotoxin analysis revealed a higher incidence of positive mycotoxin contamination in aphid-damaged maize ears compared to aphid-undamaged ones.All maize samples exhibiting excessive mycotoxin content were damaged by aphids.The identification of corresponding mycotoxin-producing strains was possible in the majority of cases where mycotoxins were detected in aphid-damaged maize ears.【Conclusion】F.verticillioides and F.proliferatum were the dominant Fusarium species isolated from aphids,bracts and kernels.The main Fusarium species isolated from aphids,bracts and kernels on the same maize ear were the same.Aphid damage significantly increased toxin accumulation levels in maize kernels,and the type of toxin was highly correlated with the detection of Fusarium species.