利用植物和土壤脂类生物标记物对高寒草甸退化演替的判别分析研究

发布时间：2018-02-05 03:35

  本文关键词： 高寒草甸 脂肪酸 脂类生物标记物 退化 GC-MS　出处：《青海大学》2015年硕士论文　论文类型：学位论文

【摘要】：利用脂类生物标记物分析环境变化或溯源有机物是一种新的研究手段,在高寒草甸退化研究方面还没有相关的报道。本研究针对高寒草甸退化与否存在不同观点的事实,通过提取和分析植物和土壤脂类物质,试图找出反映植被变化的生物标记物,为研究高寒草甸退化、合理保护和可持续利用提供科学依据。通过对植物和土壤脂肪酸提取方法的筛选、反应条件的优化,确定了最佳的脂肪酸提取方法。对提取的植物和土壤脂肪酸总的分布特征、退化以及未退化高寒草甸植物脂肪酸分布、人工草地植物脂肪酸分布、土壤总的脂肪酸分布、不同深度土壤脂肪酸的变化、退化以及未退化高寒草甸土壤脂肪酸变化以及植物与土壤脂肪酸比较研究等方面进行了比较,主要结果和结论如下:1.采用HCl-甲醇甲酯化、BF3-甲醇甲酯化以及硅烷化三种预处理提取植物中的脂肪酸,并使用GC-MS方法进行分离和鉴定,结果表明硅烷化方法效果最差,且会引起色谱柱流失,HCl-甲醇甲酯化、BF3-甲醇甲酯化方法效果较优,综合比较可鉴定脂肪酸种类、操作以及安全、回收率后确定较优提取方法为HCl-甲醇甲酯化方法。2.对HCl-甲醇甲酯化方法反应条件进行优化,确定植物较优反应条件为KOH-甲醇溶液加入量为3m L,皂化温度75℃,皂化时间5min,HCl-甲醇溶液加入量7m L,甲酯化温度65℃,甲酯化时间10min;土壤为KOH-甲醇溶液加入量为1m L,皂化温度75℃,皂化时间20min,HCl-甲醇溶液加入量7m L,甲酯化温度65℃,甲酯化时间10min。3.对植物脂肪酸进行分析,最终确定52种植物共68种脂肪酸,并根据脂肪酸分布分为微、低、中以及高频次分布4种类型脂肪酸;对高寒草甸退化以及未退化进行了比较,种类上退化高寒草甸高于未退化高寒草甸,含量上未退化高寒草甸要高于退化高寒草甸,进一步确定得出退化高寒草甸7种独有的脂肪酸,15-二十四烯酸(C24H46O2)、8,8-二甲氧基辛酸(C10H18O4)、壬酸(C9H18O2)、7,10,13-十六碳三烯酸(C16H26O2)、12-甲基十三酸(C14H28O2)、2-羟基十二烷酸(C12H24O3)、3-苯丙酸(C9H10O2)对高寒草甸退化演替具有较强的指示判别功能;对不同草地类型植物花生酸(C20H40O2)含量进行了测定,得出退化、未退化高寒草甸以及人工草地之间差异均显著(P0.05),含量依次为0.4930、0.9470、0.1585mg/g,也可作为高寒草甸退化的重要依据之一。4.对土壤脂肪酸进行了鉴定,共发现41种,碳数分布为C3-C28,饱和脂肪酸33种,单不饱和脂肪酸5种,多不饱和脂肪酸3种。土壤脂肪酸种类遵循0-10cm≥10-20cm≥20-30cm规律;0-10cm土层土壤山嵛酸含量(C22H44O2),退化与未退化草甸差异显著(P0.05),含量依次为4.7、9.6mg/kg。5.植物与土壤脂肪酸比较得出,轻度退化以及未退化高寒草甸脂肪酸种类变化呈现植物≥0-10cm土层≥10-20cm土层≥20-30cm土层;轻度退化草甸中植物与土壤脂肪酸在含量与种类上比较后发现轻度退化不能得到良好的反应。
[Abstract]:The use of lipid biomarkers for the analysis of environmental changes or traceability of organic matter is a new method, which has not been reported in the study of alpine meadow degradation. By extracting and analyzing plant and soil lipids, we try to find out the biomarkers that reflect the change of vegetation in order to study the degradation of alpine meadow. Reasonable protection and sustainable utilization provide scientific basis. The optimum fatty acid extraction method is determined by screening the extraction methods of plant and soil fatty acids and optimizing the reaction conditions. The distribution of plant fatty acids in degraded and undegraded alpine meadow, the distribution of plant fatty acids in artificial grassland, the distribution of total fatty acids in soil, the changes of fatty acids in different depths, The changes of fatty acids in degraded and undegraded alpine meadow soils and the comparison of plant and soil fatty acids were compared. The main results and conclusions are as follows: 1. The fatty acids in plants were extracted by HCl- methanol-methyl methanolation and silanization, and separated and identified by GC-MS method. The results showed that the silanization method had the worst effect. The method of HCl- methanol methyl esterification is more effective and can be used to identify fatty acid species, operation and safety. After recovery, the optimum extraction method was determined as HCl- methanol methyl esterification method. 2. The reaction conditions of HCl- methanol methyl ester reaction method were optimized. The optimum reaction conditions were determined as follows: the amount of KOH- methanol solution was 3m L, the saponification temperature was 75 鈩，

本文编号：1492005