【摘要】 草莓褐色叶斑病是中国新发现的一种病害,造成叶片坏死和果实腐烂。为明确该病原菌的致病机理,对草莓褐色叶斑病菌产生的细胞壁降解酶进行研究。采用3,5-二硝基水杨酸法(DNS法)和紫外分光光度计法测定该病原菌产生的细胞壁降解酶的种类和活性。结果发现,该病原菌能够产生多种细胞壁降解酶,即多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、多聚半乳糖醛酸反式消除酶(PGTE)和果胶甲基反式消除酶(PMTE),但不产生纤维素酶(Cx),其中PG和PMG活性较强,且PG和PMG在培养6天时活性最强,PMG在23℃条件下培养时活性最强,PG在28℃条件下培养时活性最强,静止和振荡交替培养有利于PG和PMG的产生。致病作用研究发现,果胶酶(PG和PMG)可引起果实腐烂和叶片坏死,说明其在该病原菌的致病过程中起重要作用。更多还原

【Abstract】 Pilidium concavum tan-brown leaf spot of strawberry was a new disease in China. The disease can cause leaf necrosis and fruit rot. In order to clarify pathogenesis of the pathogen causing tan-brown leaf spot of strawberry, the activity assay and the study on pathogenicity of cell wall degrading enzymes(CWDEs) ofPilidium concavum from strawberry were conducted. The types and activity of CWDEs produced by P.concavum were analyzed by the 3,5-two nitro salicylic acid method(DNS) and ultraviolet spectrophotometer method. The results showed that a series of CWDEs including polygalacturonase(PG), pectin methylgalacturonase(PMG), polygalacturonic acid trans-eliminase(PGTE) and pectin methyl trans-eliminase(PMTE) were detected in artificial culture of P. concavum, but without celluase(Cx). Among the four CWDEs,the activity of PG and PMG were significantly higher than that of PGTE and PMTE. And the optimal culture time of PG and PMG was 6 days, the optimal culture temperature of PMG was 23℃ and of PG was 28℃,shaking alternating culture was good for the production of PG and PMG. In addition, fruit rot and leaf necrosis in strawberry were caused by pectinase(PG and PMG), which indicated that the pectinase from P. concavum played an important role in the process of pathogenicity.更多还原