入侵植物加拿大一枝黄花凋落叶的化感作用及机理研究

发布时间：2018-06-01 13:46

本文选题：加拿大一枝黄花 + 凋落叶　；参考：《江苏大学》2017年硕士论文

【摘要】：化感作用已经成为外来植物成功入侵的机制之一,植物产生化感物质有多种途径,作为植物化感物质主要来源的凋落叶在土壤中降解并释放化感物质是产生化感作用的重要方式。加拿大一枝黄花是一种典型的恶性入侵杂草,有关其凋落叶的化感作用,特别是模拟实际生态环境下其化感作用的研究尚未见报道。因此,本研究以凋落叶和新鲜叶子为实验材料,莴苣为受试植物,通过在实际生态环境下的土壤盆栽实验验证加拿大一枝黄花凋落叶和叶子的化感作用;其次,通过盆栽实验模拟研究自然条件下凋落叶和幼苗根系分泌物对土壤理化性质及微生物群落结构的影响;最后,研究凋落叶的甲醇粗提液和分离纯化的2个化合物对拟南芥幼苗的生理响应;旨在探明加拿大一枝黄花凋落叶的化感作用及其化学生态学功能,阐明加拿大一枝黄花凋落叶的化感作用与其入侵扩张之间关系,为其成功入侵机制的研究提供理论依据。其结果如下:1.土壤中添加不同浓度的加拿大一枝黄花凋落叶和新鲜叶子都抑制了莴苣种子的发芽率以及幼苗的株高和生物量,抑制作用随着处理浓度的增加而增强,且新鲜叶子的抑制作用要高于凋落叶。浓度为0.05和0.1 g/g时幼苗过氧化物酶(POD)和过氧化氢酶(CAT)活性升高,当新鲜叶子浓度增加到0.2 g/g时CAT活性降低;凋落叶和新鲜叶子处理引起了幼苗氧化损伤导致丙二醛(MDA)的含量的增加。GC-MS分析了凋落叶和叶子甲醇提取液的化学组成,分别检测到27种和34种化合物,主要是萜类、酮类、酚类、醇类、生物碱类等。另外结果表明土壤和莴苣幼苗中总黄酮和总酚的含量也随处理浓度的增加而升高,这两类物质可能是产生化感作用的主要来源。一方面证明了加拿大一枝黄花凋落叶和叶子的化感作用抑制了莴苣幼苗生长且叶子的作用要强于凋落叶的;另一方面说明了实际环境中凋落叶化感作用的时效性,随着凋落叶的分解化感作用可能逐渐的降低。2.加拿大一枝黄花凋落叶与幼苗根系分泌物改变了土壤理化性质,尤其是土壤pH值从6.55变化到7.34,土壤总氮(TN)的含量从0.21增加到0.51 g/kg;凋落叶处理显著增加了细菌群落丰富度和多样性,但低浓度和高浓度之间没有差异,幼苗根系分泌物对细菌群落多样性和丰富度没有显著性影响;凋落叶和幼苗根系分泌物增加了土壤化合物的总数和总相对含量;Sphingomonas、Acidobacteriales、Gemmatimonas的相对丰度随着加拿大一枝黄花凋落叶浓度和幼苗密度的增加而地降低;Methylobacillus、Rhizomicrobium、Novosphingobium和Bradyrhizobium的相对丰度随凋落叶浓度的增加而增加,幼苗根系分泌物处理对其相对丰度没有影响;冗余分析(RDA)表明土壤pH、TN和SOM含量变化不仅与凋落叶浓度和幼苗密度都呈正相关性,而且与细菌群落之间有相关性。结果证明土壤性质、化学组成和土壤细菌群落相互作用相互影响共同改变着土壤生态过程,凋落叶和根系分泌都增加了土壤养分含量和细菌群落多样性和丰富度,为加拿大一枝黄花不同入侵时期的生长提供有利的土壤生态环境。3.加拿大的一枝黄花凋落叶粗提取液和化合物1显著的抑制了拟南芥幼苗的生长。甲醇粗提液的浓度为1 mg/m L时对根长的抑制率为66.82%,鲜重和叶绿素含量分别减少了58.46%和41.79%,且高浓度处理降低抗氧化酶活性增加了MDA的含量,浓度为0.5和1 mg/mL时都增加了幼苗可溶性糖和氨基酸含量,减少淀粉和可溶性蛋白的含量。化合物1的浓度为25、50和100μg/m L时都抑制了幼苗的生长,高浓度处理显著增加了可溶性糖含量而减少了淀粉和可溶性蛋白的含量,浓度为100μg/m L时自由氨基酸的含量升高至121.44 mg/g。化合物2在浓度为25、50和100μg/m L对拟南芥幼苗生长指标和代谢产物的含量都没有显著的影响。这些生理指标的变化证明了加拿大一枝黄花凋落叶化合物的化感活性。拟南芥幼苗的代谢产物可溶性糖和氨基酸含量的升高以及淀粉和可溶性蛋白含量的降低说明了凋落叶对拟南芥幼苗生长的化感抑制作用是通过改变植物体内正常C和N代谢途径实现的,为加拿大一枝黄花凋落叶化感作用机理研究提供了理论依据。
[Abstract]:Allelopathy has become one of the mechanisms for the successful invasion of exotic plants. There are many ways for plants to produce allelochemicals. As the main source of the plant allelochemicals, litter degrading and releasing allelochemicals is an important way to produce allelopathy. The allelopathic effect of deciduous leaves, especially in the simulated ecological environment, has not yet been reported. Therefore, this study uses litter and fresh leaves as experimental materials. Lettuce is a tested plant. The Allelopathy of the leaves and leaves of a Canadian yellow flower is verified by a potted experiment under the actual ecological environment. Secondly, the Allelopathy of the leaves and leaves of a Canadian yellow flower is verified. The effects of litter and root exudates on soil physical and chemical properties and microbial community structure under natural conditions were simulated in a pot experiment. Finally, the physiological responses of 2 compounds of methanol crude extract and separated and purified compounds to Arabidopsis thaliana seedlings were studied. Its chemical ecological function clarifies the relationship between allelopathy and invasion and expansion of the litterfall leaves of Canada. It provides a theoretical basis for the study of its successful invasion mechanism. The results are as follows: 1. the germination rate of lettuce seeds and young lettuce seeds were inhibited by adding different concentrations of Canadian leaves and fresh leaves in the soil. The plant height and biomass, the inhibition effect increased with the increase of treatment concentration, and the inhibitory effect of fresh leaves was higher than that of the leaves. The activity of peroxidase (POD) and catalase (CAT) increased at 0.05 and 0.1 g/g, and the activity of CAT decreased when the concentration of fresh leaves increased to 0.2 g/g; the treatment of litter and fresh leaves treatment. The content of malondialdehyde (MDA) was increased by oxidative damage of seedlings by.GC-MS. The chemical composition of the leaves and leaf methanol extracts was analyzed. 27 and 34 compounds were detected, mainly terpenoids, ketones, phenols, alcohols, alkaloids and so on. The results also showed that the total and total phenols content in soil and lettuce seedlings was also everywhere. The two kinds of substances may be the main source of allelopathy. On the one hand, the Allelopathy of the leaves and leaves of the Canadian leaves and leaves inhibit the growth of lettuce seedlings and the leaf effect is stronger than the litter. On the other hand, the aging of the leaf litter effect in the real environment is explained. The decomposition allelopathy of litter may gradually reduce the soil physical and chemical properties of.2. Canadian leaves and seedling root exudates, especially the soil pH value from 6.55 to 7.34, the total soil nitrogen (TN) content increased from 0.21 to 0.51 g/kg, and the litter location significantly increased the abundance and diversity of the bacterial community. There was no difference between the low concentration and the high concentration, and the root exudates of the seedlings had no significant effect on the diversity and richness of the bacterial community. The total and total relative contents of the soil compounds were increased by the leaves and the root exudates of the seedlings. The relative abundance of Sphingomonas, Acidobacteriales and Gemmatimonas along with the litterfall leaves of Canadian yellow flower The relative abundance of Methylobacillus, Rhizomicrobium, Novosphingobium and Bradyrhizobium increased with the increase of litter concentration, and the seedling root exudate treatment had no effect on its relative abundance; redundancy analysis (RDA) showed that the changes in soil pH, TN and SOM content were not only with the concentrations and young of litter leaves and young leaves. The seedling density was positively correlated and correlated with the bacterial community. The results show that soil properties, chemical composition and soil bacterial community interact and interact with each other to change the soil ecological process. The litter and root secretion increase the soil nutrient content and the diversity and richness of the bacterial community, which is a Canadian yellow flower. The growth of different invasion period provides a favorable soil ecological environment.3. Canada's yellow flower leaf coarse extract and compound 1 significantly inhibit the growth of Arabidopsis seedlings. The inhibition rate of the root length of the methanol extract is 66.82% when the concentration of 1 mg/m L, and the fresh weight and chlorophyll content are reduced by 58.46% and 41.79%, respectively. Reducing the activity of antioxidant enzymes increased the content of MDA and increased the content of soluble sugar and amino acids and reduced the content of starch and soluble protein at the concentration of 0.5 and 1 mg/mL. The growth of the seedlings was inhibited when the concentration of compound 1 was 25,50 and 100 mu g/m L, and the high concentration treatment significantly increased the soluble sugar content. The content of starch and soluble protein, when the concentration was 100 g/m L, the content of free amino acids increased to 121.44 mg/g. compound 2 at the concentration of 25,50 and 100 mu g/m L, which had no significant influence on the growth index and metabolites of Arabidopsis thaliana seedlings. The increase of soluble sugar and amino acid content and the decrease of the content of starch and soluble protein in Arabidopsis thaliana seedlings indicate that the inhibition effect of litter on the growth of Arabidopsis seedlings is realized by changing the normal C and N metabolic pathways in the plant, and the Allelopathy of Canadian one branch yellow flower. The mechanism research provides a theoretical basis.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948

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