玉米弯孢菌黑色素性质及其在致病性中的作用研究

为了探明玉米弯孢菌黑色素性质及其在致病性中的作用。利用酸碱沉淀法提取了玉米弯孢菌胞内及胞外黑色素,并分别采用紫外光谱、红外光谱研究了黑色素的性质;采用黑色素抑制实验研究了黑色素在玉米弯孢菌致病性中的作用。紫外光谱分析表明,黑色素在紫外及可见光区光谱扫描没有极值,吸光值取对数后对波长作图可以得到一条斜率为负值的直线,说明该实验提取的物质确实是一类黑色素类物质。红外光谱分析表明,玉米弯孢菌叶斑病菌菌株CX-3胞内与胞外黑色素红外光谱图有一定差异。玉米弯孢菌胞内黑色素以DHN为主,胞外是DOPA;初步证明DHN黑色素在病菌侵染感病玉米叶片过程中有一定作用。

Research on Melanin Characters and its Effect on Pathogenicity of Curvularia lunata in Maize

The research was to investigate melanin characters and its effect on the pathogenicity of Curvularia lunata in maize.Acidity-alkali sedimentation method was used to extract the extracellular and intracellular melanins in C.lunata of maize,ultraviolet and infrared spectrum were adopted to study melanin characters and the melanin inhibition test was conducted to confirm the melanin effect on the pathogenicity of C.lunata in maize.UV spectroscopic analysis indicated that melanin had no extremum when spectrum scan was conducted in ultraviolet and visible spectrum regions and charting with the wavelengths could obtain one straight line with negative slope after logarithm fetched on light-absorption value,which showed that extracted substances in this test was surely a kind of melanin derivatives.Infrared spectroscopic analysis showed that infrared spectrograms had certain differences between extracellular and intracellular melanins in leaf spot disease(C.lunata) strain CX-3 of maize.The major intracellular melanin of C.lunata in maize was DHN,while the extracellular melanin was DOPA.It was preliminarily proved that DHN had certain effects in the process that susceptive maize leaf was infected by pathogens.