本文關(guān)鍵詞： 蘆葦 濕地 植物根際促生菌 解磷 固氮　出處：《中國海洋大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：蘆葦濕地是重要的生態(tài)系統(tǒng),具有較高的經(jīng)濟價值和生態(tài)價值。本文針對近年來遼河口蘆葦濕地嚴(yán)重退化、生物量顯著降低、生態(tài)功能明顯下降等問題,分析了原因,以提高土壤中N、P元素含量和改善蘆葦濕地微生境為角度,以促進(jìn)蘆葦生長為目的,進(jìn)行蘆葦根際促生菌劑的研發(fā),并考察菌肥的施加對蘆葦生長的影響。解磷菌和自生固氮菌是植物根際促生細(xì)菌的重要組成成分,可以將土壤中植物不能直接利用的磷轉(zhuǎn)化成有效磷,將空氣中的N：通過生物固氮作用供給植物生長,提高植物對氮、磷的利用。利用蒙金娜培養(yǎng)基、Ashby培養(yǎng)基等選擇性培養(yǎng)基,從遼河口蘆葦濕地根際土壤中篩選出3株解磷菌和3株固氮菌。分別將其接種到液體培養(yǎng)基中進(jìn)行培養(yǎng),檢測菌液中可溶性正磷酸鹽和氨氮的含量變化。結(jié)果顯示,7天后,以不溶性無機磷[Ca3(PO4)2]為磷源培養(yǎng)的解磷菌液可溶性正磷酸鹽的平均含量為95.2mg·L-1,解磷率為23.8%,其中菌株P(guān)2解磷能力最強,解磷率達(dá)到26.35%；以有機磷(卵磷脂)為磷源培養(yǎng)的解磷菌液可溶性正磷酸鹽的平均含量為5.87mg·L-1,解磷率為65.2%,其中菌株P(guān)3解磷能力最強,解磷率達(dá)到73.4%；固氮菌菌液的氨氮平均含量為0.88mg·L-1,其中N2的固氮能力最強,菌液氨氮含量達(dá)到達(dá)到0.93mg·L-1。同時,通過室內(nèi)栽種蘆葦實驗,監(jiān)測蘆葦生長狀況和土壤肥力的變化。結(jié)果顯示,35天后,施加菌液的蘆葦與對照組相比,株高增長8%以上,生物量平均提高50%；施加菌液后土壤的肥力和活性明顯提高,其中速效氮、有效磷、脲酶活性、磷酸酶活性以及微生物活性與初始值相比分別提高27%、60%、60%和66%和23%。此外,有三株菌還具有分泌植物生長激素(IAA)的能力。通過菌種鑒定,這三株解磷菌分別為Bacillus megaterium、Bacillus aquimaris、Pseudomonas plecoglossicida、固氮菌分別為Pseudomonas brassicacearum、Sphingomonas mali、Enterobacter asburiae。結(jié)合本研究結(jié)果和相關(guān)文獻(xiàn)報道,這些菌種具備一定的解磷、固氮能力,同時也具備植物生防、促生、降解污染等多種功能,是制備PGPR的理想菌種。利用PCR-DGGE技術(shù)對施加菌劑后土壤微生物種群進(jìn)行解析,發(fā)現(xiàn)促生菌劑在土壤中穩(wěn)定存在并能成為優(yōu)勢種群,土壤細(xì)菌的多樣性有所提高,且對土壤原有的微生物群落不會造成明顯的干擾。綜上所述,我們認(rèn)為,這幾株菌對蘆葦生長具有顯著的促進(jìn)作用,為下一步菌種的優(yōu)化、復(fù)配以及菌劑的制備和應(yīng)用奠定基礎(chǔ),對蘆葦群落的恢復(fù)和蘆葦品質(zhì)的提升具有潛在的應(yīng)用價值。
[Abstract]:Reed wetland is an important ecosystem with high economic and ecological value. In view of the serious degradation of Reed wetland in Liaohe estuary in recent years, the paper analyzes the reasons for the serious degradation of Reed wetland, the significant decrease of biomass and the obvious decline of ecological function. In order to improve the content of N P in soil and improve the micro-habitat of Reed wetland, and to promote the growth of Reed, the research and development of rhizosphere growth-promoting agent of Reed were carried out. The effects of microbial fertilizer on the growth of Reed were also investigated. Phosphorus releasing bacteria and autogenous nitrogen-fixing bacteria are important components of rhizosphere promoting bacteria, which can convert phosphorus that plants can not use directly into available phosphorus in soil. The N in the air was supplied to plant growth through biological nitrogen fixation, and the utilization of nitrogen and phosphorus in plants was improved. The selective medium, such as Ashby medium, was used in Montana medium. Three phosphorus releasing bacteria and three nitrogen-fixing bacteria were isolated from rhizosphere soil of Reed wetland in Liaohe estuary and cultured in liquid medium to detect the changes of soluble orthophosphate and ammonia nitrogen in the liquid medium. The average content of soluble orthophosphate in the solution cultured with insoluble inorganic phosphorus [Ca3(PO4)2] was 95.2 mg 路L ~ (-1), and the phosphorus release rate was 23.8mg 路L ~ (-1). The average content of soluble orthophosphate was 5.87 mg 路L ~ (-1) and the phosphorus release rate was 65.2 mg 路L ~ (-1), among which the phosphorus releasing ability of strain P3 was the highest. The average ammonia-nitrogen content of nitrogen fixing bacteria solution was 0.88 mg 路L -1, and the nitrogen fixation ability of N 2 was the strongest, and the ammonia nitrogen content of bacteria liquid reached 0.93 mg 路L -1. At the same time, the experiment of growing Reed in laboratory was carried out. The results showed that after 35 days, the plant height and biomass of Reed treated with bacterial solution increased by more than 8%, and the soil fertility and activity increased obviously after application of bacteria solution. The available nitrogen, available phosphorus, urease activity, phosphatase activity and microbial activity were increased by 2760% and 66%% and 23.3%, respectively, compared with the initial value. In addition, three strains also had the ability to secrete plant growth hormone (IAA). The three strains were Bacillus megaterium aquimarisus Pseudecoglossicida.The nitrogen-fixing bacteria were Pseudomonas brassica acearum malioronas maliorus enterobacter buriae.According to the results of this study and the related literature, these strains have the ability of phosphorus dissolving, nitrogen-fixing, plant growth control, growth promotion, and so on. Biodegradable contamination and other functions are ideal strains for the preparation of PGPR. Using PCR-DGGE technique to analyze the soil microbial population after application of microbial agents, it is found that the bacteriostat is stable in soil and can become a dominant population. The diversity of soil bacteria has been improved, and the original microbial community of soil will not be disturbed obviously. In conclusion, we think that these bacteria can promote the growth of Reed significantly and optimize the species for the next step. The preparation and application of the compound, as well as the preparation and application of the fungicides, have potential application value for the restoration of Reed community and the improvement of Reed quality.
【學(xué)位授予單位】：中國海洋大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：S482.8;S564.2

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