入侵植物互花米草对中肋骨条藻的化感作用研究

发布时间：2018-02-09 22:54

  本文关键词： 九段沙湿地 互花米草 中肋骨条藻 化感作用 化感物质　出处：《上海大学》2016年硕士论文　论文类型：学位论文

【摘要】：本文以上海九段沙湿地国家级自然保护区的入侵物种互花米草(Spartina alterniflora)及赤潮藻中肋骨条藻(Skeletonema costatum)为研究对象,通过中肋骨条藻的生长培养实验、互花米草化感物质分析、化感物质对中肋骨条藻的培养实验,探究互花米草对中肋骨条藻的生长影响、化感物质对中肋骨条藻的抑制作用,为利用互花米草化感控制赤潮藻中肋骨条藻的扩散提供科学依据。在本研究中,分别采集互花米草活体植株、凋落物样品带回实验室,进行实验。我们设置互花米草不同构件及凋落物的不同浓度水浸液进行中肋骨条藻培养实验,探究互花米草对其是否存在化感效应;鉴定互花米草所含化感物质种类,并探究不同化感物质对中肋骨条藻生长的影响;最后设计了不同因素条件下的正交试验,得到了每个因素的最佳水平。具体结论有以下六个方面。(1)互花米草对中肋骨条藻存在化感作用。互花米草的凋落物水浸液,能够抑制中肋骨条藻的生长,而且这种抑制作用随凋落物水浸液浓度的升高而增强;凋落物水浸液改变了中肋骨条藻细胞中的叶绿素含量、SOD、POD活性和MDA含量,使得叶绿素含量、SOD、POD活性降低,MDA含量升高;(2)不同浸泡时间的凋落物浸出液对中肋骨条藻的抑制效果不同。浸泡时间为2d和5d时,浸出液对中肋骨条藻的抑制效率无明显差异,但浸泡时间为10d时,抑制率明显下降;(3)互花米草不同构件的浸出液对中肋骨条藻的生长表现为低浓度(≤0.02g?m L-1)促进,高浓度(≥0.04 g?m L-1)抑制的作用;互花米草根、茎、叶及营养液在高浓度(0.1g?mL-1)条件下对中肋骨条藻的抑制作用强度为茎叶根凋落物营养液;(4)通过GC-MS鉴定出互花米草不同构件水浸液中的化感物质主要为长链脂肪酸,主要有棕榈酸、油酸和邻苯二甲酸;且这三种物质对中肋骨条藻的生长影响呈现为低浓度促进(≤1μmol/L),高浓度抑制(≥15μmol/L),这种抑制作用随土壤水浸液浓度的升高而增强;油酸、棕榈酸、邻苯二甲酸对中肋骨条藻的生长抑制效果在同浓度下表现为油酸棕榈酸邻苯二甲酸;(5)互花米草不同构件分泌的化感物质棕榈酸、油酸和邻苯二甲酸可以通过多次投加实现低剂量水平下对中肋骨条藻生长的抑制,且抑制效果高于一次性投加化感物质的实验组;(6)投加化感物质种类、投加频次和光照强度对抑藻效果的影响大小表现为投加物质投加频次光照强度;在所设计的正交实验组中,每个因素的最佳水平为化感物质为棕榈酸,投加频次为5次,光照条件为3000 lx。化感物质对中肋骨条藻生长的影响随着投加频次的增加而增强,棕榈酸的抑制效果相对较好,光照强度对抑制效果的影响相对较小。
[Abstract]:In this paper, the invasive species Spartina alterniflora (Spartina alterniflora) and Skeletonema costatum (red tide algae) in Jiuduansha Wetland National Nature Reserve in Shanghai were studied. The allelopathic substances of Spartina alterniflora were analyzed through the growth and culture experiments of Spartina alterniflora and Skeletonema costatum. The effects of allelochemicals on the growth of Spartina alterniflora and the inhibitory effect of allelochemicals on them were studied. In this study, living plants of Spartina alterniflora were collected and litter samples were brought back to the laboratory for the purpose of controlling the diffusion of rib striped algae in red tide algae by allelopathy of Spartina alterniflora (Spartina alterniflora). The experiment was carried out. We set different components of Spartina alterniflora and different concentrations of water extract of litter to carry out the experiment of culture of Spartina costatum in order to explore the allelopathy effect of Spartina alterniflora, and to identify the allelopathic substances contained in Spartina alterniflora. The effects of different allelopathic substances on the growth of S.costatum were investigated. Finally, orthogonal experiments were designed under different conditions. The optimum level of each factor was obtained. The specific conclusions are as follows: Spartina alterniflora has allelopathic effect on Spartina costatum. The leachate of Spartina alterniflora can inhibit the growth of Spartina costatum. Moreover, the inhibitory effect was enhanced with the increase of the concentration of the water extract of litter, which changed the chlorophyll content and the activity of SOD and the content of MDA in the cells of S.costatum. The effect of litter leachate with different soaking time on the inhibition of S. costatum was different. When the soaking time was 2 days and 5 days, there was no significant difference in the inhibition efficiency of the extract to the rib striped algae. However, when soaking time was 10 days, the inhibition rate was obviously decreased.) the growth of Spartina alterniflora in different components showed low concentration (鈮，

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