特异性抑制剂三环唑对玉米大斑病菌致病力的影响

为明确DHN黑色素合成抑制剂三环唑对玉米大斑病菌Setosphaeria turcica致病力的影响,通过含毒介质系统研究了三环唑作用下玉米大斑病菌的黑色素生物合成量、附着胞的细胞孔径、膨压和病菌的致病力。结果显示,当三环唑浓度≤5μg/mL时,玉米大斑病菌菌落生长量和产孢量变化不显著,但黑色素的生成量降至对照菌株的43%;三环唑处理的病菌附着胞细胞壁孔径增大至2.7～3.3 nm,膨压降至3.75 MPa,侵染率下降37.5%,同时病斑面积显著减小。表明三环唑通过抑制玉米大斑病菌DHN黑色素合成,降低了病菌附着胞的膨压,从而导致致病力下降。

Effects of tricyclazole on the pathogenicity of Setosphaeria turcica

Tricyclazole(5-methyl-1,2,4-triazolbenzothiazole),a specific inhibitor of DHN melanin biosynthesis,was used to clarify its effects on the pathogenicity of Setosphaeria turcica.Melanin content,pore size,turgor pressure of appresoria and pathogenicity were analyzed with poison media.The results showed that tricyclazole under 5μg/mL had no inhibiting ability on hyphal growth and conidial production,but melanin biosynthesis and infection ratio were dropped to 43% and 37.5%,respectively.Appressorium pore was enlarged to 2.7-3.3nm,while turgor pressure of appresorium was decreased to 3.75MPa,resulting in lesions on susceptible host reduced greatly.Those results indicated that tricyclazole reduced the pathogenicity of S.turcica by inhibiting DHN melanin biosynthesis and turgor pressure of appresoria.