本文關(guān)鍵詞： 九段沙濕地 互花米草 中肋骨條藻 化感作用 化感物質(zhì)　出處：《上海大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：本文以上海九段沙濕地國家級自然保護(hù)區(qū)的入侵物種互花米草(Spartina alterniflora)及赤潮藻中肋骨條藻(Skeletonema costatum)為研究對象,通過中肋骨條藻的生長培養(yǎng)實(shí)驗(yàn)、互花米草化感物質(zhì)分析、化感物質(zhì)對中肋骨條藻的培養(yǎng)實(shí)驗(yàn),探究互花米草對中肋骨條藻的生長影響、化感物質(zhì)對中肋骨條藻的抑制作用,為利用互花米草化感控制赤潮藻中肋骨條藻的擴(kuò)散提供科學(xué)依據(jù)。在本研究中,分別采集互花米草活體植株、凋落物樣品帶回實(shí)驗(yàn)室,進(jìn)行實(shí)驗(yàn)。我們設(shè)置互花米草不同構(gòu)件及凋落物的不同濃度水浸液進(jìn)行中肋骨條藻培養(yǎng)實(shí)驗(yàn),探究互花米草對其是否存在化感效應(yīng);鑒定互花米草所含化感物質(zhì)種類,并探究不同化感物質(zhì)對中肋骨條藻生長的影響;最后設(shè)計(jì)了不同因素條件下的正交試驗(yàn),得到了每個因素的最佳水平。具體結(jié)論有以下六個方面。(1)互花米草對中肋骨條藻存在化感作用�；セ撞莸牡蚵湮锼�,能夠抑制中肋骨條藻的生長,而且這種抑制作用隨凋落物水浸液濃度的升高而增強(qiáng);凋落物水浸液改變了中肋骨條藻細(xì)胞中的葉綠素含量、SOD、POD活性和MDA含量,使得葉綠素含量、SOD、POD活性降低,MDA含量升高;(2)不同浸泡時(shí)間的凋落物浸出液對中肋骨條藻的抑制效果不同。浸泡時(shí)間為2d和5d時(shí),浸出液對中肋骨條藻的抑制效率無明顯差異,但浸泡時(shí)間為10d時(shí),抑制率明顯下降;(3)互花米草不同構(gòu)件的浸出液對中肋骨條藻的生長表現(xiàn)為低濃度(≤0.02g?m L-1)促進(jìn),高濃度(≥0.04 g?m L-1)抑制的作用;互花米草根、莖、葉及營養(yǎng)液在高濃度(0.1g?mL-1)條件下對中肋骨條藻的抑制作用強(qiáng)度為莖葉根凋落物營養(yǎng)液;(4)通過GC-MS鑒定出互花米草不同構(gòu)件水浸液中的化感物質(zhì)主要為長鏈脂肪酸,主要有棕櫚酸、油酸和鄰苯二甲酸;且這三種物質(zhì)對中肋骨條藻的生長影響呈現(xiàn)為低濃度促進(jìn)(≤1μmol/L),高濃度抑制(≥15μmol/L),這種抑制作用隨土壤水浸液濃度的升高而增強(qiáng);油酸、棕櫚酸、鄰苯二甲酸對中肋骨條藻的生長抑制效果在同濃度下表現(xiàn)為油酸棕櫚酸鄰苯二甲酸;(5)互花米草不同構(gòu)件分泌的化感物質(zhì)棕櫚酸、油酸和鄰苯二甲酸可以通過多次投加實(shí)現(xiàn)低劑量水平下對中肋骨條藻生長的抑制,且抑制效果高于一次性投加化感物質(zhì)的實(shí)驗(yàn)組;(6)投加化感物質(zhì)種類、投加頻次和光照強(qiáng)度對抑藻效果的影響大小表現(xiàn)為投加物質(zhì)投加頻次光照強(qiáng)度;在所設(shè)計(jì)的正交實(shí)驗(yàn)組中,每個因素的最佳水平為化感物質(zhì)為棕櫚酸,投加頻次為5次,光照條件為3000 lx�；形镔|(zhì)對中肋骨條藻生長的影響隨著投加頻次的增加而增強(qiáng),棕櫚酸的抑制效果相對較好,光照強(qiáng)度對抑制效果的影響相對較小。
[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，

本文編號：1499049