化学物质对水稻纹枯病菌黑色素形成的影响

Effects of chemical substances on melanin formation of Rhizoctonia solani AG-1 IA

【目的】水稻纹枯病是由立枯丝核菌Rhizoctonia solani AG-1 IA融合群引起的真菌病害,本研究旨在明确外界培养条件与水稻纹枯病菌黑色素形成的关系。【方法】采用菌丝生长速率法和紫外分光光度法,测定化学肥料[500μg/mL K2SO4、NaH2PO4、CO(NH2)2]、金属离子(5μg/mL CuSO4、FeSO4、ZnSO4)、抗氧化剂(5μg/mL槲皮素、桑色素、抗坏血酸)和对照(300μg/mL莨菪碱、50μg/mL儿茶酚、水)对水稻纹枯病菌菌丝生长速率、菌核数量、菌核鲜质量和干质量以及黑色素含量的影响。【结果】500μg/mL K2SO4、NaH2PO4和CO(NH2)2,5μg/mL CuSO4和ZnSO4,5μg/mL槲皮素、桑色素和抗坏血酸以及50μg/mL儿茶酚溶液对水稻纹枯病菌黑色素的形成均有促进作用。其中,500μg/mL的CO(NH2)2处理下,水稻纹枯病菌产生黑色素最多,为113.2 mg;而300μg/mL的莨菪碱处理下,水稻纹枯病菌产生黑色素最少,为37.4 mg。【结论】水稻纹枯病菌黑色素的产生与菌丝生长速率和菌核发育没有必然的联系,即抑制菌丝生长和菌核发育的化学物质,不一定能够抑制黑色素的形成。本研究结果可为水稻纹枯病防控机理的研究提供依据。

【Objective】Rice sheath blight,caused by Rhizoctonia solani AG-1 IA,is an important fungal disease.The purpose of this study was to determine the relationship between external culture conditions and melanin formation of R.solani AG-1 IA.【Method】The effects of four different treatment groups,i.e.chemical fertilizer group[500μg/mL K2SO4,NaH2PO4,CO(NH2)2],metal ion compound group(5μg/mL CuSO4,FeSO4,ZnSO4),antioxidant group(5μg/mL quercetin,morin,vitamin C)and control group(300μg/mL hyoscyamine,50μg/mL catechol,water),on the mycelial growth rate,sclerotia number,sclerotial fresh weight and dry weight as well as melanin content of R.solani AG-1 IA were determined by measuring mycelial growth rate and ultraviolet spectrophotometry.【Result】Chemical fertilizer[500μg/mL K2SO4,NaH2PO4,CO(NH2)2],metal ion compound(5μg/mL CuSO4,ZnSO4),antioxidant(5μg/mL quercetin,morin,vitamin C)and catechol(50μg/mL)could promote the formation of melanin.Under the treatment of 500μg/mL CO(NH2)2,the melanin content of R.solani AG-1 IA was the highest(113.2 mg),while under the treatment of 300μg/mL hyoscyamine,the melanin content of R.solani AG-1 IA was the lowest(37.4 mg).【Conclusion】Melanin formation is not necessarily related to mycelial growth and sclerotial development,i.e.the chemical substances,which have inhibitory effect on mycelial growth and sclerotial development,might have no inhibition on melanin formation.The results of this study provide a basis for understanding the mechanism for prevention and control of rice sheath blight.