摘 要

为了研究凤阳山国家级自然保护区内典型林分植物根系分泌物，并测定其种类与含量，本研究以浙江省凤阳山保护区内4种主要林分类型（阔叶林、杉木林、针阔混交林和竹林）为对象，采用野外原位收集的方法收集根系分泌物，并运用热裂解气质联用仪，测定出不同林分根系分泌物的种类和含量，通过比较不同林分中根系分泌物的异同，分析林分类型对根系分泌物的影响以及根系分泌物对于根际土壤微环境的作用。结果表明：

1. 从阔叶林分中共检出7类19种物质，从针阔叶林分中共检出5类23种物质，从竹林林分中共检出7类18种物质，从杉木林中共检出8类17种物质，其共同含有3类7种物质。
2. 四种林分的根系分泌物主要有醛类、醇类、胺类、有机酸类、脂肪酸类、酮类、苯甲酸酯类衍生物、脂肪酸酯类、蛋白质类和生长因子类。
3. 其中，仅从阔叶林分中检出醛类物质，为1-萘甲醛，占2.88%，仅从是杉木林中检出氨基酸类物质，为L-Serine，占2.45%。在针阔混交林中检测出大量胺类物质，占34.3%，而在竹林、杉木林中的含量均低于2%，阔叶林分中未检测出胺类物质。阔叶林、竹林林分和杉木林中均检测出含酮类物质，含量分别为3.24%，1.07%、4.07%，而针阔混交林中未检测出此类物质。
4. 四种林分共同含有的6种根系分泌物，分别是丙烯醇、甘油、2,6-二叔丁基-4-甲基环己醇、草酸、棕榈酸、硬脂酸，在含量上的变化趋势一致，含量由多到少均表现杉木林＞阔叶林＞竹林＞针阔叶林分。

关键词：根系分泌物；凤阳山；林分类型；原位收集法

Study on types of root exudates in typical forests of Fengyang mountain

ABSTRACT

In the area of typical forest plant root exudates of Fengyang Mountain National Nature Reserve, and determine the type and content, based on the 4 main forest types in Zhejiang province Fengyang mountain reserve type (broad-leaved forest, fir forest, coniferous forest and bamboo forest) as the object, methods using field collected root in situ secretion, and use of pyrolysis gas chromatography-mass spectrometry instrument, determination of kinds and contents of root exudates in different stands, the similarities and differences of different stand in the secretion of root comparison, analysis of influence of forest types on root exudates and root secretion on Rhizosphere effect. The result shows:

(1) Detection of 7 types of 19 kinds of material from the detection of 5 types of broad-leaved forest, coniferous and broad-leaved forest of 23 kinds of material from the detection of 7 types of 18 kinds of material from the bamboo forest, detection of 8 types of 17 kinds of material from the Chinese fir forest, the common contains 3 class 7 materials.

(2) The root exudates of four kinds of forest stand are aldehydes, alcohols, amines, organic acids, fatty acids, ketones, benzoic acid esters, fatty acid esters, proteins and growth factors.

(3) Among them, only aldehydes were found in broad-leaved forest stands, which were 1- naphthalene and formaldehyde, accounting for 2.88%. Only amino acids were detected in Chinese fir forests, accounting for L-Serine, accounting for 2.45%. A large amount of amines was detected in coniferous broad-leaved mixed forest, accounting for 34.3%, while in bamboo forest and Chinese fir forest, the content was lower than 2%, and no amines were detected in broad-leaved forest. Broadleaf forest, bamboo forest and Chinese fir forest were detected with ketones. The contents were 3.24%, 1.07%, 4.07%, and coniferous forest did not detect such substances.

(4) Six kinds of root exudates of four stands included, respectively, allyl alcohol, glycerol, 2,6- tert butyl -4- methyl cyclohexanol, oxalic acid, palmitic acid, stearic acid, the same trend in the content, the content from the show of Chinese fir forest, broad-leaved forest, bamboo forest, coniferous and broad-leaved forest.

Keywords: root exudates; Fengyang mountain; stand types; in-situ collection

目 录

1 引言 - 1 -

1.1国内外研究背景 - 1 -

1.2根系分泌物的收集 - 2 -

1.3根系分泌物的分离纯化 - 3 -

1.4根系分泌物的组成 - 4 -

2 研究区概况 - 5 -

2.1地理位置 - 5 -

2.2气候特征 - 5 -

2.3植被类型 - 5 -

3 研究方法 - 6 -

3.1样品收集 - 6 -

3.2测定方法 - 6 -

4 实验结果与讨论 - 7 -

4.1不同林分植物根系分泌物种类 - 7 -

4.2 不同林分各种植物根系分泌物所占百分比 - 8 -

4.3 不同林分所含有的相同植物根系分泌所占百分比 - 12 -

4.4讨论 - 15 -

5 结论与展望 - 17 -

5.1结论 - 17 -

5.2展望 - 17 -

致 谢 - 18 -

参考文献 - 19 -

1 引言

1.1国内外研究背景

土壤生态系统是陆地生态系统的重要组成部分，其中植物根系是系统中最为重要的部分。随着对植物与土壤关系的探究和根际微生态学的建立和发展，各种根系分泌物的种类和作用以及根际微生态学渐渐成为研究重点^[1]。根系是化感物质进入土壤的重要通道，根系分泌物中含有大量具有化感活性的物质，伴随着化感物质释放、迁移与转化，林木根际微域成为化感物质累积的重要场所，其研究内容主要是根系分泌物的分离提取和鉴定及其对于林分类型的影响和应用潜力等方面^[2]。

越来越多的证据表明，根系分泌物是植物与土壤进行物质交换和信息传递的重要载体物质,是植物响应外界胁迫的重要途径,是构成植物不同根际微生态特征的关键因素,也是根际对话的主要调控者，对根系分泌物数量、种类的研究是植物营养、化感作用、环境修复以及林分类型改造等研究领域的重要内容^[3-4]。

统计表明,已发现的根系分泌物利I类有200种以上。植物种类不同,根系分泌物种类有差异；同一植物在不同生理状况下,根系分泌物的种类也有差别,并且根系分泌物各物质含量也存在差异。所以,根系分泌物的种类及含量能反应出植物的生长状况。根系分泌物是植物与周围环境进行物质交换、信号传递的重要媒介,不同的林分根际环境，其根系分泌的种类和含量分泌也有很大的不同，研究由根系分泌物介导的植物-土壤-林分环境三者之间的相互关系已成为当前国内外优先研究的重要领域^[5]。