【作者】 周天；

【导师】 郭继勋；

【作者基本信息】 东北师范大学 ， 生态学， 2007， 博士

【摘要】 化感作用的研究是一门新兴的交叉学科,近年来受到生态学家和化学家的共同重视。该领域的研究成果将成为研究植物群落结构、群落演替的机理和拟定植被恢复的措施等提供重要的理论依据。一些研究成果在生物农药的创制方面还具有重要的现实意义。黄蒿（Artemisia scoparia）为菊科蒿属植物,一年或二年生草本,在我国各地广泛分布在农田、路旁、荒地等。可以观察到在黄蒿与其他植物共生的群落中,有时在以黄蒿为优势种的群落中,其它植物的生长明显受到抑制,对自然植被、农业生产形成较大的危害。本文首次较全面地对黄蒿可能产生的化感物质及其化感作用进行了研究,探讨了化感作用在植被恢复演替过程的作用机理,并进行了化感物质人工合成和化感缓释载体材料合成的研究,为黄蒿群落的化学生态学研究及其在生产实践中的利用提供科学依据。本研究主要结论如下:1.黄蒿富含大量挥发性物质,本研究采用水蒸汽蒸馏法从黄蒿中提取挥发油,试验其对受体植物箩卜（Raphanus sativus）、苜蓿（Medicago sativa）、白菜（Brassia pekinensis）、玉米（Zea mays）的种子萌发和幼苗生长的影响,实验结果表明黄蒿挥发油对萝卜、苜蓿、白菜、玉米种子萌发和幼苗生长具有不同程度的抑制作用。抑制种子萌发最明显的是萝卜种子,抑制幼苗生长最明显的是苜蓿。而对玉米种子萌发和幼苗生长的抑制作用不明显,说明不同科的植物对化感物质的耐受性不同。黄蒿的化感作用与挥发油中含量较高的萜烯类化合物有关,萜烯类化合物通常是重要的化感物质,黄蒿中萜烯类物质共检出12种,占45.04%。在天然植物群落中,黄蒿广泛蔓延的原因,除了其本身具有较强的繁殖能力和耐旱性、根系发达外,并通过释放体内所含有的化学成分对其他植物产生抑制作用,是其中重要原因之一。试验黄蒿挥发油对植物的化感作用的同时,也研究了其对昆虫的毒杀活性,为开发无公害的植物性杀虫剂,合理利用黄蒿资源提供了科学依据。2.黄蒿可以通过淋洗释放化感物质,其水溶物对不同科属的受体植物紫花苜蓿、地肤（Kochia scoparia）、野稗（Echinochloa crusgali）、苋（Amaranthus tricolor）、羊草（Leymus Chinese）的种子萌发和幼苗生长产生一定的影响。黄蒿水溶物对不同受体植物或对同一受体植物的不同部位（幼苗或幼根）有不同的化感效应（促进、抑制）。抑制作用在紫花苜蓿、地肤、苋的发芽实验中较羊草、野稗更敏感,且幼根比幼苗更敏感。关于化感物质的浓度效应,苋和羊草的根长生长随水溶物浓度的增高抑制作用增强。黄蒿水溶物对受体植物表现为低浓度促进,高浓度抑制的双重效应,当水溶物浓度为0.002g·ml^-1时,促进效应较一致,而大于0.05g·ml^-1时,抑制效应极其显著。3.本研究通过用0.15 g·ml^-1,0.10 g·ml^-1,0.05 g·ml^-1,0.01 g·ml^-1 （DW/V）四种不同浓度和不同器官的黄蒿水溶物对羊草的幼苗生长、光合速率和SOD、CAT、POD 3种保护酶进行了化感活性的测定,实验证明,不同浓度的黄蒿水溶物对羊草幼苗生长均有抑制作用,浓度越高抑制作用越强。黄蒿不同器官水溶物对羊草幼苗的生长也有不同的抑制作用,其中叶的抑制作用最强。黄蒿对羊草的抑制作用主要是通过影响三种保护酶和光合作用来实现。黄蒿水溶物处理使羊草体内活性氧代谢系统失衡,破坏或降低活性氧清除剂,增加活性氧的产量,从而破坏了膜结构,影响羊草的生长发育。化感物质能显著地降低受体植物的叶绿素含量、或叶绿素合成的酶系统,黄蒿对羊草幼苗叶片光合效能的限制,使羊草正常的生长发育缺少物质基础,发育迟缓。4.试验不同生长期、不同器官的黄蒿水溶物对紫花苜蓿种子萌发和幼苗生长的影响,检验黄蒿对苜蓿的化感作用;同时用0.1g·ml^-1,0.05g·ml^-1,0.01g·ml^-1,0.002g·ml^-14个不同浓度的黄蒿水溶物来检验对苜蓿体内SOD、POD、CAT活性的影响,研究其化感作用的机理。实验证明,不同生长期、不同器官的黄蒿水溶物对紫花苜蓿乃至其不同部位（幼苗或幼根）有不同的化感效应（促进、抑制）;紫花苜蓿体内的SOD、POD、CAT可以通过提升酶活力来抵御黄蒿水溶物中化感物质对其产生的胁迫,随着黄蒿水溶物浓度的增加,CAT、SOD、POD的酶活力有先升高后下降的趋势,这可能是由于黄蒿水溶物的化感作用胁迫强度超过了二者的调节能力。黄蒿水溶物中的化感物质影响了受体植物体内保护酶的活性,造成了膜脂过氧化程度的加剧,破坏了膜的结构和功能,这可能是黄蒿化感作用的机制之一,且有可能是多种化感效应的起始点。5.为了研究黄蒿的化感物质,我们对挥发油和水溶物的成分进行了分离、分析,采用水蒸汽蒸馏法从黄蒿中提取挥发油,利用气相色谱-质谱联用（GC/MS）技术对黄蒿挥发油进行测定,共鉴定出38种化合物,检出物占总质量87.53%,其中重要的化感物质萜烯类化合物12种,占45.04%;用石油醚、乙酸乙酯和正丁醇对黄蒿的水溶物进行分步多次萃取,并试验每一萃取组分对不同受体植物种子萌发和幼苗生长的影响,检验其是否具有化感活性,结果证明正丁醇萃取组分有较强的化感作用,对其进一步分离纯化,利用生物活性检测实验、GC/MS技术和核磁共振技术对得到的三个样品进行了分析测试,通过GC/MS的分析,A样品的主要成分为酚类、烯烃类、醇类、有机酸类、酯类等,均为化感类物质。通过核磁共振确定了两种具有化感活性的单体成分B为6,7-二甲氧基香豆素,C为邻苯二甲酸二异辛酯。二者都有报道证明为化感物质。6.化感物质在植物体内一般含量较少,提取费时费力,收率较低,极大地限制了对其进行深入的研究和在农林业上的应用。化感物质的人工合成是深入化感作用研究的重要方向,因此,以邻苯二甲酸酐、异辛醇为原料用对甲苯磺酸作为酯化反应的催化剂,化学合成了黄蒿中的化感物质邻苯二甲酸二异辛酯,并通过其对受体植物种子萌发和幼苗生长的影响实验,证明了化学合成的邻苯二甲酸二异辛酯具有较强的化感作用。探索了一条化学合成化感物质的途径,使化感物质的深入研究与实际应用成为可能。7.缓释载体材料为延长化感物质作用持效期、提高药剂的稳定性等提供了可能,是节约药剂用量、减少污染的重要途径之一,可以达到释放数量可控、释放时间可控和释放空间可控的目的。目前关于化感物质缓释载体材料的研究还未见报道。为研究化感物质的缓释载体材料,本研究首次分别以含有两种化感物质阿魏酸、没食子酸的聚丙烯酰胺（PAM）纤维为模板,采用化学氧化聚合法,分别合成了阿魏酸、没食子酸掺杂的聚苯胺（PANI）纳米缓释载体材料。并通过红外光谱（IR）、X-射线粉末衍射（XRD）以及电子扫描电镜（SEM）对掺杂态PANI的结构和形态进行了检测。结果表明,所制备材料确为阿魏酸、没食子酸掺杂态的PANI。SEM研究结果表明:PANI的形态表现为纳米态。另外,对模板中化感物质含量以及不同氧化剂和苯胺单体物质的量比对掺杂效果的影响进行了研究探讨。由于聚苯胺的掺杂与解掺杂特点,化感物质则很容易在碱性环境中从表面积较大的纳米态聚苯胺中脱落下来,从而达到化感物质缓释的目的。更多还原

【Abstract】 Allelopathy was defined as a process involving secondary metabolites produced by plants, micro-organisms, viruses, and fungi that influences growth and development of biological systems. The allelopathy may be so striking that competition for resources does not explain why, in plant communities, many species appear to regulate one another through the production and release of chemicals, stimulators or inhibitors. It is in the nature extensive existence, it have the more important function in plant communities succession, the vegetation instauration and agriculture, forestries production. Allelopathy is a new marginal area of research , being common valued by the ecologists and chemists in recent years.Artemisia scoparia, an annual or biannual herbaceous plant with strong smell, is widely distributed in fields, roadsides and wastelands in China. It can be observed in the symbiotic communities of A. scoparia and other plants, A. scoparia always is dominance, sometimes in the communities that the A. scoparia concentrated growth, the growth of other plants is subjected to the inhibition.It produced bigger harmfulness to the natural vegetation, agriculture. The purpose of this study is to investigate whether the allelopathy have some function in the formation and successions of A. scoparias communities .For the first time,in this paper the allelochemicals and allelopathy of A. scoparia were studied completely, the mechanism of A. scoparia allelopathy on plant communities succession, the vegetation instauration was studied.It’s allelochemical and slow release carrier was synthesized.It can provide scientific evidence for chemical ecology research of A.scoparia community and it’s allelopathic application.The studies have the following conclusions:1. An important path of higher plant releasing allelopathic substances is volatilization. The A. scoparia contains abundant of volatile oil.Through vapor distillation and extraction method, essential oil could be obtained. In order to study the allelopathy of A. scoparia volatile oil , Raphanus sativus、Medicago sativa、Brassia pekinensis、Zea mays were used as receptor to study the effects of volatile oil on the seed germination and the growth of roots and seedlings, The results showed volatile oil has different inhibition effects on seed’s germination and seedling growth of R. sativus, M. sativa, B. pekinensis and Z.mays. The germination of R. sativus seeds treated with the volatile oil was 27.3% than the untreated seeds. Root and seedling growth of M. sativa were strongly inhibited too, reduced 19.2% and 33.4% than untreated seeds. The inhibition on Z.mays was not obvious. It is proved that the different families plants have different resistance to allelochemicals.The main compositions of volatile oil is usually terpene compounds. The terpene compounds are usually important allelopathic substance. In this study the compositions of A. scoparia volatile oil were analyzed, there were 12 kinds of terpene compounds, which were the main components and constituted 45.04% of the total mass from volatile oil. In natural plant community, the reason of A. scoparia extensive rampanting is various, in addition to it has the physiological characteristic of stronger breeding ability and bearing drought and having flourishing root system, the inhibition function of chemical compositions in the plant to other plants is one of the important reasons. We also studied the effect of volatile oil of Artemisia scoparia poisoning insects, revealed the chemical relationships between Artemisia scoparia and some other organisms, which can provide scientific bases for developing botanic pesticides without social effects of pollution and rationally utilizing Artemisia scoparia resources.2. The aqueous extracts of A. scoparia affect seed germination and seedling growth of receptor plants. The effects are different on different receptor plants, even on different parts of one plant. There are more inhibitive effects on Medicago sativa ,Kochia scoparia , Amaranthaceae retroflexus than Leymus Chinese, Echinochloa crusgali,and seedling length than root length .The effect is stimulative when the concentration is 0.002g·ml^-1, gradually decreased , is appeared and even changed into suppressive effect when the concentration is higher than 0.05 g·ml^-1.3. Four different concentrations (0.15 g·ml^-1,0.10 g·ml^-1,0.05 g·ml^-1,0.01 g·ml^-1 （DW/V）) and different organs of A. scoparia were used to study it’s mechanism on M. Chinese.The result shows that four different aqueous extracts have inhibition on M. Chinese,the effect of inhibition is increased with the concentration. The aqueous extracts of different organs have inhibition on M. Chinese,the effect of leave is stronger. The allelopathy of A. scoparia on M. Chinese is done through to affect the activity of protective-enzyme and photosynthesis.4.We used different stages ,different organs and four different concentrations (0.1g·ml-1,0.05g·ml^-1,0.01g·ml^-1,0.002g·ml^-1 ) of A. scoparia aqueous extract to study it’s allelopathy mechanism on M. sativa. The aqueous extract of A. scoparia affects dynamics of height , fresh weight of M. sativa .The activities of CAT、POD and SOD in M. sativa were enhanced to resist the of A. scoparia .The activities of CAT、POD and SOD gradually decrease when the concentration of the aqueous extract increases. The mechanism of the allelopathy is similar that the allelopathy of A. scoparia affects the activity of protective-enzyme of receptor plant and breaks the structure and function of membrane.5. The yellow volatile oil was gotten by the method of vapor distillation with a mean yield of 0.38% （V/DW）. The volatile oil was analyzed with GC/MS.Thirty eight compounds were identified and constituted 87.53% of the total mass. There are 12 terpene compounds, which are the main components and constituted 45.04% of the volatile oil from A.scoparia. Allelochemicals of the aqueous extracts were extracted ,purified and analysed by GC/MS . Sample A mainly include phenol、terpene、alcohol、ester、organic acid .Two monomer allelochemicals were identified by nuclear magnetic resonance （NMR）,B is 6,7-Dimethylesculetin （DE） ,C is di（2-ethylhexyl）phthalate（DOP）.6. Because the content of allelochemicals is lower in plant,we hope to find a way getting a lot of allelochemicals. Chemical synthesization is an important way.We synthesized the Di（2-ethylhexyl）phthalate（DOP） by using p-toluene sulphonic acid as catalyst and proved it’s allelopathy. We find a new pathway of obtaining allelochemicals through chemical synthesization.It is very important for deeper research and application of allelochemicals7. For the first time, we studied slow release technology on allelochemicals, polyaniline（PANI） dope with allelochemicals （gallic acid or ferulic acid ）was prepared by using gallic or ferulic acid/PAM fibers template. The structure and morphology of the PANI were characterized by IR spectra, XRD patterns, and SEM images. The results indicated that the products were PANI doped with gallic acid or ferulic acid. And the morphology of the PANI nanorods with diameter in 200-300 nm was obtained. In addition, the new material can release allelochemicals （gallic acid or ferulic acid ） while environment pH is increased .It can improve the effect of allelochemicals in the process of application.更多还原