發(fā)布時(shí)間：2018-04-28 08:57

  本文選題：三七 + 根際土壤�。� 參考：《昆明理工大學(xué)》2017年碩士論文

【摘要】：三七是一種重要的經(jīng)濟(jì)和藥用植物,但連作障礙嚴(yán)重。土壤微生物群落的變化被認(rèn)為是三七死亡的主要原因,但對其變化規(guī)律和作用機(jī)理仍不清楚,因此系統(tǒng)研究三七栽種期微生物群落的變化情況,無疑具有重要意義。本文以不同季節(jié),健康和生病,種植年限分別為1年、2年和3年的三七根際土壤樣本為研究對象,在DNA和RNA水平對細(xì)菌群落結(jié)構(gòu)和功能進(jìn)行了研究。首先,提取三七根際土壤中微生物的總DNA后進(jìn)行擴(kuò)增子測序,對三七根際土壤細(xì)菌總?cè)郝溥M(jìn)行研究。結(jié)果表明,三七根際土壤細(xì)菌具有很高的豐度和多樣性。旱季樣品的多樣性高于雨季,生病三七高于健康三七。三七根際土壤中優(yōu)勢菌群為變形菌門、擬桿菌門、酸桿菌門、綠彎菌門和放線菌門。生病三七根際土中富集了大量的假單胞菌,Rickettsiaceae和amurshkyense。在功能上,生病與健康三七在氨基酸代謝合成、tRNA合成過程以及次生產(chǎn)物代謝方面存在差異。其次,提取三七根際土壤總RNA,對三七根際活躍細(xì)菌群落進(jìn)行研究。結(jié)果顯示,細(xì)菌活躍群落是總體群落的一個(gè)子集,不同樣本中活躍的細(xì)菌群落不同,而不同的群落可能由不同的環(huán)境因素塑造。與健康三七相比,生病三七根際土壤活躍的細(xì)菌群落中獨(dú)有的四個(gè)門是藍(lán)藻門、擬桿菌門、放線菌門和酸桿菌門,其中芽孢桿菌屬和Anoxybacillus屬對其他細(xì)菌種群具有抑制作用。影響根際活躍細(xì)菌群落的主要環(huán)境因素是有機(jī)質(zhì)速效氮速效鉀磷速效磷。最后,利用宏基因組的方法開展了三七根際土壤中微生物群落組成和功能研究。三七根際土壤微生物主要參與碳水化合物代謝、氨基酸代謝、能量代謝、核酸代謝、輔因子和維生素合成代謝、復(fù)制與重組、膜運(yùn)輸?shù)壬�化過程。生病三七根際土壤微生物在氨基酸代謝,環(huán)境因子響應(yīng)和信號轉(zhuǎn)導(dǎo)等方面的基因豐度升高了,生病三七根際土壤微生物對環(huán)境的適應(yīng)性更強(qiáng)。三七根際土壤細(xì)菌群落在土壤氮循環(huán)、甲烷代謝和硫代謝方面具有重要作用,是三七根際土壤中化學(xué)循環(huán)的重要驅(qū)動(dòng)力。本文系統(tǒng)的開展了三七根際土壤細(xì)菌群落結(jié)構(gòu)及其功能研究,首次對三七根際活躍細(xì)菌群落進(jìn)行研究,初步揭示了三七根際土壤細(xì)菌群落在連作過程中的演替規(guī)律,闡明了三七根際土壤微生物的生態(tài)功能。從土壤微生態(tài)學(xué)的角度為三七的可連續(xù)種植及其疾病控制提供了重要信息。
[Abstract]:Panax notoginseng is an important economic and medicinal plant, but continuous cropping obstacles are serious. The change of soil microbial community is considered to be the main cause of death of Panax notoginseng, but it is still unclear about its changing law and mechanism. Therefore, it is of great significance to systematically study the variation of microbial community in panax notoginseng during planting period. The structure and function of bacterial community were studied at DNA and RNA levels in rhizosphere soil samples of Panax notoginseng with different seasons, health and illness, and planting years of 1 year, 2 years and 3 years, respectively. Firstly, the total DNA from rhizosphere soil of Panax notoginseng was extracted and sequenced, and the total bacterial community in rhizosphere soil of Panax notoginseng was studied. The results showed that the rhizosphere bacteria of Panax notoginseng had high abundance and diversity. The diversity of dry season samples was higher than that of rainy season, and that of sick panax notoginseng was higher than that of healthy ones. The dominant bacteria in rhizosphere soil of Panax notoginseng were Proteus, Bacteroides, Acidobacterium, Chlorophyta and Actinomycetes. A large number of rickettsiaceae and amurshkyense. were enriched in the rhizosphere soil of Panax notoginseng. In function, there were differences between sick and healthy Panax notoginseng in amino acid metabolism, synthesis of tRNA and metabolism of secondary production. Secondly, total RNAs were extracted from rhizosphere soil of Panax notoginseng and the active bacterial communities in rhizosphere of Panax notoginseng were studied. The results showed that the active bacterial community was a subset of the total community. The active bacterial communities in different samples were different, but different communities might be shaped by different environmental factors. Compared with the healthy Panax notoginseng, the four unique phylum in the active rhizosphere soil community of Panax notoginseng were cyanobacteria, Bacteroides, actinomycetes and acidobacterium, among which Bacillus and Anoxybacillus had inhibitory effects on other bacterial populations. The main environmental factors affecting rhizosphere active bacteria community were organic matter available nitrogen, available potassium, available phosphorus. Finally, the composition and function of microbial community in rhizosphere soil of Panax notoginseng were studied by macrogenome method. Rhizosphere soil microorganisms of Panax notoginseng are mainly involved in carbohydrate metabolism, amino acid metabolism, energy metabolism, nucleic acid metabolism, cofactor and vitamin synthesis metabolism, replication and recombination, membrane transport and other biochemical processes. The gene abundance of soil microbes in diseased rhizosphere of Panax notoginseng increased in amino acid metabolism, environmental response and signal transduction, and the adaptability of soil microbes to environment was stronger in diseased rhizosphere of Panax notoginseng. Bacterial community in rhizosphere of Panax notoginseng plays an important role in nitrogen cycle, methane metabolism and sulfur metabolism, and is an important driving force of chemical cycle in rhizosphere soil of Panax notoginseng. In this paper, the structure and function of rhizosphere soil bacterial community of Panax notoginseng were systematically studied, and the active bacterial community in rhizosphere of Panax notoginseng was studied for the first time, and the succession of rhizosphere soil bacterial community of Panax notoginseng during continuous cropping was preliminarily revealed. The ecological function of rhizosphere soil microorganisms of Panax notoginseng was expounded. Soil microecology provides important information for continuous planting and disease control of Panax notoginseng.
【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：S154.3;S567.236

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相關(guān)期刊論文 前1條

1 繆作清;李世東;劉杏忠;陳昱君;李云華;王勇;郭榮君;夏振遠(yuǎn);張克勤;;三七根腐病病原研究[J];中國農(nóng)業(yè)科學(xué);2006年07期

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本文編號：1814607