丛枝菌根真菌对土壤有机物降解的影响

发布时间：2018-01-26 05:09

本文关键词： 丛枝菌根真菌土壤有机质降解土壤腐生微生物 ~(15)N/~(13)C双标记　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：丛枝菌根真菌(Arbuscular Mycorrhizal Fungi, AMF)是土壤中广泛存在的共生真菌,AMF与80%以上的陆生植物形成共生体。一方面,AMF从宿主植物中获得碳水化合物；另一方面,AMF为宿主植物吸收矿物质元素和水,提高植物的抗逆性。由于AMF的碳源唯一从植物中获得,AMF能否和如何影响土壤有机物分解,成为近年来研究热点。本研究的科学假说为,低磷土壤条件下,AMF可能通过获取磷素,进而促进土壤有机物的分解。采用13C/15N双标记法有机物降解过程；并研究豆科和非豆科宿主植物与丛枝菌根真菌共生对土壤有机质分解影响的差异；用PCR-DGGE实验分析有机物分解过程中土壤细菌群落的组成、磷酸酶活性。主要结果如下。(1) 土壤不同磷水平下AMF对土壤有机质分解的影响土壤磷浓度,对AMF侵染率、宿主植物生物量和有机质的降解均产生显著影响。随着土壤磷浓度的升高,AMF的侵染率显著降低。在低磷土壤条件下,AMF显著增加了宿主植物的生物量和15N的含量,显著降低了有机质分解袋中有机氮和有机碳的含量,表明低磷土壤下AMF促进土壤有机物的分解。(2) 豆科和非豆科植物与AMF共生对土壤有机质分解的影响与豆科植物紫花苜蓿(Medicago sativa)相比,非豆科植物平车前(Plantago depressa)显著增加对15N的吸收,显著增加了有机质分解袋中有机氮和有机碳的降解。紫花苜蓿中,AMF没有显著降低有机氮和有机碳的含量。平车前中,AMF显著降低了有机氮和有机碳的含量。(3) 低磷土壤条件下AMF对土壤细菌群落的影响AMF明显改变了有机质分解袋中细菌群落的组成。在碱性土壤环境中,AMF显著降低了酸性磷酸酶活性,显著增加了碱性磷酸酶活性。
[Abstract]:Arbuscular Mycorrhizal Fungida (AMF) is a symbiotic fungus widely existed in soil. AMF forms symbionts with more than 80% terrestrial plants, on the one hand, carbohydrates are obtained from host plants. On the other hand, the host plant absorbs mineral elements and water, and improves plant stress resistance. Because the carbon source of AMF is only obtained from plants, can and how to affect the decomposition of soil organic matter. In recent years, the scientific hypothesis of this study is that AMF may be obtained from phosphorus under low phosphorus soil conditions. In order to promote the decomposition of soil organic matter, 13C / 15N double labeling method was used to degrade organic matter. The effects of symbiosis of host plants and arbuscular mycorrhizal fungi on the decomposition of soil organic matter were studied. The composition of soil bacterial community during the decomposition of organic matter was analyzed by PCR-DGGE experiment. The main results are as follows: 1) the effect of AMF on the decomposition of soil organic matter under different phosphorus levels and the infection rate of AMF on soil phosphorus concentration. The biomass of host plants and the degradation of organic matter were significantly affected. The infection rate of AMF decreased significantly with the increase of soil phosphorus concentration. AMF significantly increased the biomass and 15N content of the host plant, and significantly reduced the organic nitrogen and organic carbon content in the organic decomposition bag. The results showed that AMF promoted the decomposition of soil organic matter in low phosphorus soil. (2) the symbiotic effect of legumes and non-legumes and AMF on the decomposition of soil organic matter and alfalfa (Leguminosae). Medicago sativa. Plantago depressa, a non-legume plant, significantly increased the absorption of 15N, increased the degradation of organic nitrogen and organic carbon in organic matter decomposition bags, and increased the organic carbon degradation in alfalfa. AMF did not significantly reduce the contents of organic nitrogen and organic carbon. AMF significantly reduced the contents of organic nitrogen and organic carbon. Effect of AMF on soil bacterial Community in low phosphorus soil AMF significantly changed the composition of bacterial community in organic matter decomposition bag. AMF significantly decreased the activity of acid phosphatase and increased the activity of alkaline phosphatase.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S154.3

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