小麦中致病真菌的分离鉴定及熏蒸对其毒力的影响

Isolation and Identification of Pathogenic Fungi in Wheat and Influence of Fumigation on Their Virulence

小麦受镰刀菌的感染会导致赤霉病、真菌毒素污染和减产,镰刀菌对粮食安全有着严重威胁。通过对小麦中镰刀菌株进行分离鉴定,分离出的三种菌株N1、N2、N3分别属于禾谷镰刀菌属、亚洲镰刀菌属和高秆镰刀菌属。利用产毒基因检测和真菌毒素检测对三株菌株玉米赤霉烯酮、呕吐毒素和伏马毒素的产毒情况进行分析,结果一致显示N1和N3能产生玉米赤霉烯酮和呕吐毒素,均含有PSK和Tri5两种产毒基因,而N2不产生这三种毒素。进一步通过臭氧和二氧化氯进行气体熏蒸,探究气体熏蒸对分离出的三株菌株的影响,通过观察孢子形态、菌丝体长度、菌丝形态,结果表明二氧化氯熏蒸能有效抑制菌丝生长和孢子萌发,低浓度二氧化氯(300 mg/L)处理0.5 h,可明显抑制菌丝的生长。而臭氧只能抑制孢子萌发,对菌丝的生长没有明显的抑制作用。

Fusarium infection of wheat can lead to scab,mycotoxin contamination and yield reduction.Fusarium is a serious threat to food security.In this study,the Fusarium strains in wheat were isolated and identified.The three strains N1,N2 and N3 belonged to Fusarium graminearum,Fusarium asiaticum and Fusarium culmatum,respectively.The production of zearalenone,vomitoxin and fumonisin by the three strains was analyzed by toxin-producing gene detection and mycotoxin detection.The results showed that N1 and N3 could produce zearalenone and vomitoxin,but did not produce fumonisin,while N2 did not produce these three toxins.In this study,ozone and chlorine dioxide were further used for gas fumigation to explore the effect of gas fumigation on the three strains isolated.By observing the spore morphology,mycelium length and mycelium morphology,the results showed that chlorine dioxide fumigation could effectively inhibit the growth of mycelium and spore germination,while ozone could only inhibit spore germination and had no obvious inhibitory effect on the growth of mycelium.