外来植物北美车前入侵土壤的微生物特征与理化性状相关性分析
时间:2019-11-01 18:55 来源:毕业论文 作者:毕业论文 点击:次
| 摘要: 北美车前原产于北美，是二年生草本植物。是果园、旱田及草坪杂草，当种群密度大，花粉数目较多时，可能会导致花粉过敏症。在本课题中采集狗牙根、早熟禾、剪股颖、高羊茅4种处理草和北美车前不同密度的混和种植土样，分为4个密度，进行放线菌、真菌的分离培养计数，对各菌株作显微镜观察和描述；对不同处理草和不同种植密度的多个土样进行水分、pH、总氮等理化指标测定。研究得到北美车前入侵地的土壤pH总变化趋势是在5.5—7.0之间明显增长的，说明北美车前入侵改变了土壤的酸碱性，使土壤向碱性方向移动。北美车前入侵对当地土壤中的全氮量影响趋势不统一，对不同处理草影响不同。土壤中放线菌的数量也随着北美车前的入侵程度的加深而增多，中度入侵时影响最大，这之间还有一个反馈作用，随后减小，说明北美车前可以适当促进土壤中放线菌的生长。北美车前入侵改变了当地土壤的酸碱性，使得土壤向偏碱性方向改变，改变了土壤中放线菌的生长环境，导致放线菌数量发生改变，土壤中的微生物种类结构发生变化。41755 毕业论文关键词： 北美车前；梯度种植；理化；分离鉴定 Exotic plant invasion of soil microbial characteristics and physical and chemical character correlation analysis Abstract: North American car is native to North America, is a biennial herbaceous plant. Is the lawn weeds, orchards, dry field, and when the population density is big, pollen number is large, may cause the pollen allergy. In this subject acquisition bermudagrass, Kentucky bluegrass, cut glume grass, tall fescue, 4 kinds of processing and north American car mixed planting soil samples of different density, pided into four density, to count, cultivation of actinomyces and fungi in for each strain microscope observation and description; For different processing grass and multiple soil samples of different planting density on moisture, pH, physical and chemical indexes such as total nitrogen determination. To their invasion of the north American car of the soil pH between 5.5 7.0 is the total change trend obvious growth, suggests that the north American car invasion changed the acid and alkaline soil, soil moving in the direction of alkaline. North American car invasion on the local amount of total nitrogen in the soil affect trend, different effects on different processing. The number of actinomycetes in the soil also increased with the degree of the invasion of the north American car, moderate invasion was most affected, there is a feedback between the role, then decreases, and that the north American car can promote the growth of actinomyces in soil appropriately. North American car invasion changed local soil acid, alkaline, make the change in the direction of an alkaline soil, change the growth of actinomyces in soil environment, lead to actinomyces quantity change, the structure change in the soil microbial species. Keywords: North American car; Gradient planting;;The physical and chemical properties;Separation identification 目录 1 绪论 1 1.1 本课题国内外研究现状概述 1 1.1.1 中国外来入侵植物研究现状 1 1.1.2 外来植物入侵的危害 3 1.1.3 我国防治和管理现状 4 1.2本课题的研究目的和意义 4 2 实验材料和方法 9 2.1 材料试剂 9 2.2 仪器设备 9 2.3 实验流程 10 2.4 实验内容 10 2.4.1 对北美车前入侵前后的土样采样 10 2.4.2 土壤理化性质的测定 11 2.4.3 土壤微生物的分离和计数 13 2.4.4 菌株的分类和初步鉴定方法 13 (责任编辑：qin) |