摘要Fusarium oxysporum是果蔬采后主要的病原真菌，对果蔬的贮藏具有极大的危害，因此，寻找有效的防治方法具有重要的意义。本研究从腐烂的番茄中分离主要致病菌，经rDNA-ITS法进行鉴定后，利用不同抑菌物质（亚磷酸盐、碳酸氢钠）处理病原菌，确定最低抑菌浓度，并通过生理、生化指标以及果实接种实验，研究了亚磷酸盐、碳酸氢钠与病原菌发育及致病力的关系。结果表明，分离的病原菌为Fusarium oxysporum；亚磷酸盐、碳酸氢钠的抑菌效果均与浓度成正比；在一定的抑菌浓度下，可以显著抑制Fusarium oxysporum的孢子萌发，延缓芽管伸长及菌丝扩展速度，降低病原菌生物量积累，引起病原菌糖吸收障碍，并对番茄枯萎病有明显的防治作用；其中一定浓度的亚磷酸盐的抑菌效果相对高于碳酸氢钠。本研究为果蔬采后病原菌Fusarium oxysporum的防治提供了新的思路。46976

Abstract

    Fusarium oxysporum is a major postharvest pathogen and quite harmful to fruit and vegetable preservation. Therefore, looking for effective control methods has the vital practical significance. In this study, we isolated the main pathogen from naturally infected tomatoes (Solanum lycopersicum) and identified it by rDNA-ITS method. Then minimum inhibitory concentrations (MICs) of exogenous antifungal substances (Sodium bicarbonate、phosphite) were confirmed. The relationship between five antifungal substances and growth or pathogenicity of the pathogen were evaluated via assessment of physiological, biochemical indexes and inoculation experiment of fruits. The results indicated that the isolated pathogen was identified as Fusarium oxysporum. The Sodium bicarbonate and The phosphite could inhibit the growth of Fusarium oxysporum and the behavior were dose-dependent. Furthermore, antifungal substances all could inhibit spore germination, reduce germ tube elongation and mycelium extension rate, lower biomass accumulation, result in sugar malabsorption of Fusarium oxysporum, and effectively control wilt diseare of tomato caused by Fusarium oxysporum. Moreover, A certain concentration of phosphate  is higher than that of sodium bicarbonate in the antibacterial effect. This study provides new approaches to control postharvest horticulture pathogen Fusarium oxysporum.

毕业论文关键词 ：Fusarium oxysporum； 内转录间隔区(ITS)； 抑菌物质； 贮藏保鲜

  Keywords：Fusarium oxysporum;  Internal transcribed spacer (ITS);  Antifungal substance; Preservation and freshness

目    录

摘    要 3

Abstract 3

1  引 言 4

1.1  尖孢镰刀菌（Fusarium oxysporum）简介 4

1.2  果蔬采后病害的研究现状 4

1.3  研究意义 5

2  材料与方法 5

2.1  菌株及主要试剂 5

2.2  形态特征观察及rDNA-ITS鉴定病原菌 5

2.3  通过F. oxysporum孢子萌发率确定碳酸氢钠、亚磷酸盐的最低抑菌浓度 6

2. 4  利用显微镜镜头标尺通过十字交叉法测量最低抑菌浓度组F. oxysporum的芽管长度 7

2. 5  测量F. oxysporum菌落的扩展 7

2. 6  测量F. oxysporum菌丝生物量的积累及总糖吸收 7

2. 7  苹果活体接种实验 8

2. 8  数据统计与分析