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玉米鞘腐病菌产生的胞壁降解酶及其在致病过程中的作用

标题: 玉米鞘腐病菌产生的胞壁降解酶及其在致病过程中的作用
英文标题: Cell-wall Degrading Enzymes Produced by Fusarium Species and Their Pathogenicity to Corn Sheath
作者: 李朋朋
出版时间: 2012-01-01
所在大学: 河北农业大学
关键词: 玉米鞘腐病,致病力,胞壁降解酶,毒素
英文关键词: Corn sheath rot,Pathogenicity,Cell wall degrading enzyme,Toxin
论文级别: 硕士
学位: 学位论文
导师: 董金皋%曹志艳
专业: 植物学
提交时间: 2012
摘要: 玉米鞘腐病是近年我国玉米生产上普遍发生的一种鞘部病害.该病在玉米生育中后期发生,主要危害叶鞘形成不规则形病斑,病斑灰褐色至黑褐色或水渍状腐烂.本研究对引起玉米鞘腐病的层出镰刀菌、串珠镰刀菌和禾谷镰刀菌的胞壁降解酶活性、毒素活性、致病力等方面进行了比较研究;采用生长速率法对多菌灵、戊唑醇、烯唑醇、氟硅唑等化学杀菌剂进行了室内毒力测定,并在此基础上进行了玉米鞘腐病的田间防效试验.主要结果如下:1.层出镰刀菌、串珠镰刀菌和禾谷镰刀菌在改良Marcus培养液中产生胞壁降解酶的最佳条件均为静置培养,最佳培养时间和pH值分别为纤维素酶(Cx):10 d、pH6,多聚半乳糖醛酸酶(PG):6 d、pH6,果胶甲基半乳糖醛酸酶(PMG):6 d、pH5,多聚半乳糖醛酸反式消除酶(PGTE)和果胶甲基反式消除酶(PMTE):6 d、pH9.2.3种镰刀菌产生的PG、Cx和PMG的活性普遍高于同种镰刀菌产生的PGTE和PMTE的活性.3.层出镰刀菌的致病力、胞壁降解酶活性、毒素活性高于串珠镰刀菌和禾谷镰刀菌.4.多菌灵、戊唑醇、烯唑醇、氟硅唑及多菌灵和戊唑醇1:1、2:1配比对层出镰刀菌均有较好的抑制作用,EC50值分别为17.27 mg/L、23.40 mg/L、24.21 mg/L、26.01 mg/L、18.48 mg/L和25.83 mg/L;多菌灵、戊唑醇及多菌灵与戊唑醇1:1对玉米鞘腐病具有较好的田间防效,分别达93.34%、89.19%和91.49%,玉米增产20.61%、15.46%和18.84%.
英文摘要: Corn sheath rot as one new corn disease developed rapidly in most corn-planting regions in China recently. It usually occurred during late growth period and infected the corn sheath, then caused irregular circular spots with grayish brown to dark brown lesions or wet rot. In this study, the activity of cell-wall degrading enzymes and toxin and pathogenicity of three Fusarium species which caused corn sheath rot have been researched in details and growth rate methods was used to estimate the toxicity of Carbendazim, Tebuconazole, Diniconazole, Flusilazole and the mixture of Carbendazim and Tebuconazole with 1:1, 2:1, based on which the field control efficiency tests were carried out. The results can be showed as follows:1. The culture conditions of cell wall degrading enzymes which produced by three Fusarium species were studied, The best culture manner was static culture; the optimal incubation time and pH of Cx was 10 d and 6, PG was 6 d and 6, PMG was 6 d and 5, PGTE and PMTE were 6 d and 9.2. The activities of PG, Cx and PMG produced by these Fusarium species were much higher than the ones of PGTE and PMTE.3. The pathogenicity and activities of extracellular wall degrading enzymes and toxin produced by F. proliferatum were more higher than that of F. moniliforme and F. graminearum.4. Four fungicides had better inhibition on F. proliferatum and the EC50 were 17.27 mg/L, 23.40 mg/L, 24.21 mg/L, 26.01 mg/L, 18.48 mg/L and 25.83 mg/L, respectively. The field control efficiency of Carbendazim, Tebuconazole and the 1:1 mixture of Carbendazim and Tebuconazole were 93.34%, 89.19% and 91.49%, the yields increase rate were 20.61%, 15.46% and 18.84%.