氟硅唑对核盘菌生长和致病作用影响的研究

发布时间：2018-07-26 13:19

【摘要】：核盘菌[Sclerotinia sclerotiorum(Lib.)de Bary]是一种世界分布的死体营养型植物病原真菌,对多种农作物和蔬菜造成严重危害,对其防治仍然以化学药剂为主。高效、广谱、低毒杀菌剂氟硅唑可用于防治多种作物上的多种病原菌,但是在我国还未用于防治菌核病。本论文研究了核盘菌对氟硅唑的敏感性、氟硅唑的盆栽防效以及低剂量氟硅唑对核盘菌的刺激作用,为氟硅唑防治菌核病提供科学依据。通过测定氟硅唑对150株核盘菌菌株的抑制中浓度(EC50),建立了核盘菌对氟硅唑的敏感性基线,氟硅唑敏感性分布为单峰型,EC50平均值为0.1237μg/mL±0.0491(SD),分布范围为0.0227~0.3436μg/mL。盆栽试验表明:氟硅唑在油菜叶片上的保护作用高于多菌灵的保护作用。在含0.03、0.06和0.12μg/mL氟硅唑PDA上生长的菌丝细胞膜通透性降低,透射电镜观察发现菌丝细胞壁增厚。核盘菌在含有0.005~0.16μg/mL氟硅唑的PDA上生长后,与对照组相比对菌株HN-24致病力最高可增强19.81%。低剂量氟硅唑对核盘菌的致病力有显著刺激作用,在盆栽油菜上,喷施0.002~2μg/mL的氟硅唑对菌株HN-24致病力的刺激作用在8.28%~10.72%之间。喷施0.02、0.2μg/mL氟硅唑对核盘菌的致病刺激作用在接种12 h后表现出来,表明这种刺激作用的机理为直接刺激作用。但是氟硅唑处理没有改变核盘菌对H2O2的耐受力。在PDA上使用0.005~0.04μg/mL的氟硅唑预处理可增强核盘菌对氟硅唑及其相同作用机制杀菌剂的耐受力,而降低对不同作用机制杀菌剂的耐受力。但是在含有氟硅唑的PDA上处理后,却降低了菌丝在无药PDA上的生长速率。
[Abstract]:Sclerotinia sclerotiorum [Sclerotinia sclerotiorum (Lib.) de Bary] is a kind of dead vegetative plant pathogenic fungi distributed in the world, which causes serious harm to many crops and vegetables. The fungicides with high efficiency, broad spectrum and low toxicity can be used to control many kinds of pathogens in many crops, but they have not been used to control sclerotinia sclerotiorum (Sclerotinia sclerotiorum) in China. In this paper, the sensitivity of Sclerotinia sclerotiorum to flusiazole, the control effect of flusiazole in pot and the stimulation of low dose of flusiazole to Sclerotinia sclerotiorum were studied in order to provide scientific basis for the prevention and treatment of sclerotiorum by flusiazole. By determining the median inhibitory concentration (EC50) of flusiazole on 150 strains of Sclerotinia sclerotiorum, a baseline was established for the sensitivity of Sclerotinia sclerotiorum to flusiazole. The mean value of the single peak EC50 distribution was 0.1237 渭 g/mL 卤0.0491 (SD), and the distribution range was 0.02270.3436 渭 g / mL. Pot experiment showed that the protective effect of flusiazole on rape leaves was higher than that of carbendazim. The membrane permeability of mycelium grown on 0.03 渭 g/mL and 0.12 渭 g/mL flursiazole PDA was decreased, and the cell wall of mycelium was thickened by transmission electron microscope. After the growth of Sclerotinia sclerotiorum on PDA containing 0. 005 ~ 0. 16 渭 g/mL flursiazole, the pathogenicity of Sclerotinia sclerotiorum to HN-24 was increased by 19. 81% compared with the control group. The pathogenicity of low dose flusiazole on Sclerotinia sclerotiorum was significantly stimulated. In pot rape, the pathogenicity of strain HN-24 was increased by spraying flusiazole with 0.002 渭 g/mL in the range of 8.28% or 10.72%. The pathogenicity of flusiazole (0.02 渭 g/mL) on Sclerotinia sclerotiorum was observed 12 h after inoculation, which indicated that the mechanism of the stimulation was direct stimulation. However, flusiazole treatment did not change the Sclerotinia sclerotiorum resistance to H2O2. The pretreatment of flusiazole with 0.005 ~ 0.04 渭 g/mL on PDA could enhance the resistance of Sclerotinia sclerotiorum to flusiazole and the same mechanism of fungicides, but reduce the tolerance to different mechanisms of fungicides. However, the growth rate of mycelium on drug-free PDA was decreased after treatment on PDA containing flusiazole.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S432.44

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