【作者】 曹光球；

【导师】 林思祖；

【作者基本信息】 福建农林大学 ， 森林培育， 2006， 博士

【摘要】 化感作用是指植物生长过程或植物腐烂过程中产生的化感物质对邻近植物生长的干扰，它是植物之间传递信息的一种方式，是森林生态系统中普遍存在的一种现象，对森林群落的结构、功能、效益及发展均有重大影响，是一不可忽视的化学生态因子。1984年Rice把化感作用定义为“植物(包括微生物)向环境释放化学物质，从而对其它植物产生有利或有害的影响”。植物通过挥发、淋溶、分泌、分解、腐解等途径向环境释放化感物质。 杉木是我国南方最重要的用材树种，连栽导致地力衰退。杉木自毒作用是导致杉木林地力衰退、生产力下降的一个重要原因。本论文首先分析了不同浸提方式条件下杉木叶、根及根际土壤化感物质以及不同腐解阶段杉木枯枝落叶分解土化感物质对杉木种子发芽及其幼苗的化感效应；在GC-MS鉴定自毒物质的基础上，分析了逆境胁迫条件下杉木自毒物质对杉木幼苗的化感效应；除此之外，本文还探讨了杉木主要混交树种对杉木的种间化感作用，这不仅可以从机理上研究杉木人工林的自毒作用，深入了解杉木对自毒物质的反应及自毒物质的作用强度的变化，全面评价杉木自毒作用在杉木林中的地位，揭示杉木自毒作用在杉木林生态系统中的自然化学调控机理，而且通过杉木与主要混交树种种间生化作用的研究，为解决杉木连栽障碍问题，实现杉木林地的可持续经营，防止杉木连栽生产力下降在理论上和实践上都具有重要的理论参考价值及实践意义。研究结果表明： (1)杉木纯林中的土壤、枯落叶、半分解枯落叶和杉木鲜叶、枝条、树皮、树根的水浸液和上述七种水浸液添加乙烯吡咯啉酮K-300(pvp)后得到的溶液对杉木种子的萌发具有不同程度的影响。所有水浸液均表现出高浓度下抑制种子萌发，随着浓度降低，抑制作用减弱、消失，甚至转变为促进作用的规律；其中根和鲜叶的水浸液抑制作用最强，但水浸液添加pvp后得到的抑制作用明显减弱，且在低浓度时表现出促进作用。 (2)杉木枝叶水浸液对杉木幼苗的生长、生理及其各器官营养元素含量具有不同的影响。从生长量上，在整个培养过程，总体上的趋势基本上表现为高浓度的枝叶水浸液对杉木幼苗苗高及地径生长及光合指标、呼吸指标具有不良的影响；从生物量上看，各器官生物量随杉木枝叶水浸液浓度的上升而逐渐降低。从生物量分配率上看，杉木水浸液在低浓度时有利于叶、皮、根、枝和干等各器官的生物量分配率，高浓度时有利于枯枝落叶的生物量分配率。大部分营养器官C、N、Mg、K、Ca、Cu、Mn、Fe和Zn的含量随着水浸液的降低而升高，Al含量随着水浸液浓度的升高而升高；同一器官不同水浸液各个营养元素含量不同，同一元素也因水浸液浓度的不同而在不同的营养器官产生不同的分配。通过GC-MS气相质谱鉴定，杉木枝叶水浸液的化感物质主要是二氢香豆精、顺式合欢醛、丙酸甲酯、肉桂酸、阿魏酸、1-环丁基乙醇。 (3)采用正交试验方法及超临界流体萃取技术提取的杉木根提取物对杉木种子发芽存在不同程度的影响。生物检测结果表明，与酒精对照相比：超临界流体1萃取条件下，萃取参数8条件杉木根提取物对杉木种子绝对发芽率、绝对发芽势、胚根、胚轴、鲜重和干重等发芽指标均表现出抑制作用，萃取参数2、3、4和6等条件杉木根提取物对杉木种子鲜重表现出抑制作用，萃取参数5条件杉木根提取物对绝对发芽势和鲜重起抑制作用，萃取参数1和7等条件杉木根提取物对除胚根以外的其它各发芽指标均起抑制作用；同一参数条件三种浓度(50mg/kg、100mg/kg、200mg/kg)处理之间相比，萃取参数1、2、3、6、7和8更多还原

【Abstract】 Allelopathy is one of the most common phenomena in nature. Rice （1984） gave the following definition of allelopathy: "Any direct or indirect harmful or beneficial effect by one plant （including microorganisms） on another through the production of chemical compounds that escape into the environment". Allelochemicals were released by processes as volatilization, root exudation, leaching, and decomposition et alChinese fir （Cunninghamia lamcealata （Lamb.） Hook） spread through seventeen provinces in south China, which is recommended as the most important timber tree species in south China. The field investigation suggested that Chinese fir had poor establishment and low productivity, and would lead to soil degradation when grown after itself again. So, the bioassays seed germination was used to assays the effect of leaf, root, rhizosphere soil allelochemicals extracted by different solvent on Chinese fir seed germination and growth of seedling. Based on results of GC-MS, the effect of autointoxicational allelochemicals on seed germination and growth of seedling under different stress were done; Beside, lead to the Chinese-fir autointoxicationa, this paper also studied mutual relation between Chinese-fir autointoxicational allelochemicals and associated tree species’s allelochemicals. This paper not only can research the mechanism of Chinese fir autointoxication, research Chinese fir reaction to autointoxicational allelochemicals and change of function of autointoxicational allelochemicals, reveal the nature chemical mechanism of Chinese fir autointoxication in eco-system of Chinese fir stand, but also can all settle the problems of poor establishment and low productivity, and would lead to soil degradation when grown after itself again, realize the sustainable management of Chinese fir stand. All of these have the most important theoretically referenced value and practical significance for low productivity of Chinese fir.（1） The aqueous extracts of leaf litter, half decaying leaf litter, fresh leaf, branch, bark, root of Chinese fir and the surface layer soil under chinese-fir pure stand affect the seed germination and the growth of bud of chinese-fir seed, that in high concentration of the above-mentioned aqueous extracts, seed germination and growth of bud are inhibited significantly; That with the concentration decreasing, the inhibitory effects get weak, disapper and even turn into stimulating effects and that after polyvinyl pyrrolidone k-300（pvp） were added into above-mentioned aqueous extracts, the inhibitory effects become weaker significantly.（2） Different concentrations of leaf and branch aqueous extracts had different effect on growth of Chinese fir seedling. The result showed that the high concentrations of leaf extracts had inhibitory effect on growth, index of photosynthesis and index of respiration of Chinese fir seedling the biomass of Chinese-fir seedling treated with leaf and branch aqueous extracts after six years were decreased, the higher the concentration was, the higher the inhibited effect was, and low concentration had positive effect on the leaf、bark、 root、branch and stem biomass distribution, high concentration had positive effect on the litter biomass distribution; That C、 N、 Mg、 K、 Ca、 Cu、 Mn、 Fe and Zn content in most organs of Chinese fir seedling showed that the higher concentration was, the less content was; but Al content show that the higher concentration was, the more content was.（3） Root extract of Chinese fir by supercritical fluid extract technology 1 （only CO₂ as entrainer, the following is the same） and fluid 2 （after adding the entrainer ethanol, the following is the same） at different parameter inhibited the germination summit and each germination index at different level. The bioassay revealed that except parameter 1, 7 and 8, the extract of supercritical fluid one had inhibitory effects on most germination更多还原