植物提取物的抑菌活性及其对番茄连作土壤微生物多样性的影响

发布时间：2018-10-17 20:37

【摘要】：番茄是广西秋冬季的主要优势蔬菜之一。近年来,广西番茄生产规模逐年扩大,目前已形成以百色市田阳县、南宁市武鸣县等县市为主的大规模番茄生产基地。番茄的大规模生产虽然有助于节约生产和运输成本,但同时在同一区域常年连续地种植番茄,导致连作障碍现象普遍,目前广西上述主要的番茄产区已频现诸如青枯病、枯萎病等诸多土传病害,严重影响番茄的产量和品质。对此,生产者往往过度使用化学农药,不仅使病原菌产生抗药性,而且还会引起产品质量安全和环境污染等问题。植物提取物具有良好的抑菌、杀菌作用,拥有广泛的应用前景。本试验基于广西较为丰富的植物资源,采用煮沸和浸泡两种方式提取7种植物的抑菌成分,并研究这7种植物提取物对番茄青枯病病原菌和枯萎病病原菌的抑制作用。同时,选取抑菌效果良好的植物提取物处理番茄连作土壤,研究其对土壤生物学特性及土壤微生物多样性的影响,旨在为解决番茄连作障碍问题提供理论依据。本试验的结果表明：(1)蛇床子、大黄、虎杖、薄荷4种植物在10g/L和15g/L浓度下,对番茄青枯病和枯萎病病原菌具有良好的抑菌效果；同时,对于大部分植物而言,提取方法以煮沸法优于浸泡法。(2)施用多菌灵会使土壤可培养微生物数量降低,但施用大黄提取物却能增加土壤可培养微生物数量,而且,植物提取物对土壤可培养微生物数量的影响效果优于多菌灵,表明：植物提取物比化学农药更有助于改良土壤,三种植物提取物中以大黄提取物效果最好。(3)施用多菌灵会降低番茄连作土壤β-葡萄糖苷酶、氨肽酶、磷酸酶活性。但植物提取物处理则大多数能增加上述三种酶的活性,结果表明：植物提取物处理土壤比化学农药多菌灵更有助于提升土壤肥力、改良土壤,其中,处理浓度以15g/L时效果最佳。(4)施用多菌灵会降低土壤MBC。与之相比,15g/L的大黄和虎杖提取物比多菌灵更有助于提高番茄连作土壤MBC和土壤MBN,从而改良土壤肥力。其中,浓度以15g/L的大黄和虎杖提取物效果最佳。(5)番茄连作导致土壤细菌多样性、丰富度和均匀度指数下降；植物提取物和多菌灵均能不同程度地提高土壤细菌多样性、丰度和均匀度指数,但植物提取物的效果要优于多菌灵,其中以浓度为100g/L的大黄效果最好。测序结果表明：无论是番茄连作、多菌灵和植物提取物处理的土壤中,土壤细菌均以Unclutured bacterium为主；但植物提取物处理土壤中,除了上述不可培养的细菌属外,还发现含有Flavobacterium sp., Chitinophagaceae bacteria、Pseudomonas sp.和Sphingomonas sp.等属；其中Pseudomonas sp.和Sphingomonas sp.被视为土壤中的有益微生物。
[Abstract]:Tomato is one of the main dominant vegetables in autumn and winter in Guangxi. In recent years, the scale of tomato production in Guangxi has been expanded year by year, and now it has formed a large scale tomato production base in Baise Tianyang County, Nanning City Wuming County and other counties and cities. Although the large-scale production of tomatoes helps to save production and transportation costs, but at the same time in the same region of the perennial continuous cultivation of tomatoes, the phenomenon of continuous cropping obstacles is widespread. At present, the main tomato production areas mentioned above in Guangxi have been frequently found such as bacterial wilt. Many soil-borne diseases, such as Fusarium wilt, seriously affect the yield and quality of tomato. For this reason, producers often overuse chemical pesticides, which not only lead to drug resistance of pathogens, but also lead to problems of product quality, safety and environmental pollution. Plant extracts have good bacteriostatic and bactericidal effects and have a wide application prospect. Based on the abundant plant resources in Guangxi, the antibacterial components of 7 plants were extracted by boiling and soaking, and the inhibitory effects of the seven plant extracts on the pathogens of tomato bacterial wilt and Fusarium wilt were studied. At the same time, plant extracts with good bacteriostatic effect were selected to treat tomato continuous cropping soil, and the effects on soil biological characteristics and soil microbial diversity were studied in order to provide theoretical basis for solving the problem of tomato continuous cropping obstacle. The results showed that: (1) four species of plants, such as Cnidium cnidii, Rhubarb, Polygonum cuspidatum and Menthol, had a good bacteriostasis effect on bacterial wilt and Fusarium wilt of tomato at the concentration of 10g/L and 15g/L, and at the same time, for most plants, The extraction method was better than the soaking method. (2) applying carbendazim could reduce the number of culturable microorganisms in soil, but the application of rhubarb extract could increase the number of culturable microorganisms in soil. The effect of plant extracts on the number of culturable microorganisms in soil was better than that of carbendazim, which indicated that plant extracts were more helpful than chemical pesticides in improving soil. (3) the application of carbendazim could reduce the activities of 尾 -glucosidase, aminopeptidase and phosphatase in tomato soil. However, most of the plant extracts can increase the activity of the above three enzymes. The results show that the treatment of plant extracts can improve soil fertility and improve soil fertility more than the chemical pesticide carbendazim. (4) the application of carbendazim can reduce soil MBC.. Compared with carbendazim, the extracts of rhubarb and Polygonum cuspidatum from 15g/L could improve soil fertility by improving soil MBC and MBN,. The concentration of rhubarb and Polygonum cuspidatum extract from 15g/L was the best. (5) continuous cultivation of tomato resulted in the decrease of soil bacterial diversity, richness and evenness index, and the plant extract and carbendazim could improve the soil bacterial diversity to some extent. Abundance and evenness index, but the effect of plant extract was better than carbendazim, and rhubarb with concentration of 100g/L was the best. The results of sequencing showed that Unclutured bacterium was the main bacteria in the soil treated with carbendazim and plant extract, but in the treatment of plant extract, except for the unculturable bacteria, Also found to contain Flavobacterium sp., Chitinophagaceae bacteria,Pseudomonas sp. And Sphingomonas sp. Equal genus; of which Pseudomonas sp. And Sphingomonas sp. It is regarded as a beneficial microorganism in the soil.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S436.412.1;S154.3

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