苹果树腐烂病菌致病因子及其与菌株致病性的关系

Pathogenic Factors Produced by Valsa mali var.mali and Their Relationship With Pathogenicity of Different Strains

以苹果树腐烂病菌强致病菌LXS080601和弱致病菌LXS081501为试材,采用二硝基水杨酸（DNS）法和高效液相色谱法（HPLC）测定酶活性和毒素的差异,以期探寻苹果树腐烂病菌不同致病力菌株产生酶和毒素的差异及其与菌株致病性的关系。结果表明：LXS080601在树皮培养基和离体枝条中均产生5种毒素,而LXS081501接种后仅检测到3～4种毒素,且除培养基中产生的间苯三酚外,其余毒素量均显著低于LXS080601;2株菌株均可分泌5种细胞壁降解酶,但酶活性存在显著差异,LXS080601产生的酶活性显著高于LXS081501,且酶活性达到高峰时间较短;说明腐烂病菌产生的酶活性、毒素种类和数量与菌株的致病性强弱呈正相关。

Taking Valsa mali var.mali of strain LXS080601with high virulence and strain LXS081501with weak virulence as materials,the enzyme activities and toxins were analyzed using dinitrosalicylic acid（DNS）and high performance liquid chromatography（HPLC）methods,to explore the difference of cell wall degrading enzymes and toxins produced by different strains of Valsa mali and the relationship between pathogenic factors and pathogenicity.The results showed that5kinds of toxins were all detected in‘Fuji＇bark medium and detached branches inoculated with strain LXS080601including protocatechuic acid,p-hydroxybenzoic acid,p-hydroxybenzene propanoic acid,p-hydroxyacetophenone and phloroglucinol,however,only 3～4kinds of toxins were produced by strain LXS081501in two treatments,respectively.The amount of the toxins produced by LXS081501was significantly lower than that produced by LXS080601,except for phloroglucinol produced in‘Fuji＇bark medium.In addition,two strains could produce 5kinds of cell wall degrading enzymes including celluase,β？glucosidase,polymethylgalacturonase,xylanase and polygalacturonase,but the enzyme activities were significantly difference.The enzyme activities produced by LXS080601were higher than that produced by LXS081501,and the corresponding days were shorter when maximum enzyme activities were detected.The results in this research indicated that a positive relationship existed between enzyme activities,amount and kinds of toxins produced by V.mali and pathogenicity of different strains.