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杂草五爪金龙对其入侵地土壤酶活性与微生物群落的影响 总被引：1，自引：0，他引：1
五爪金龙是粤东地区入侵性极强的外来杂草,其对入侵地土壤生态系统可能存在明显的改造作用．在野外调查的基础上,确定3个被五爪金龙重度入侵的生境作为采样地,通过室内实验测定与分析五爪金龙对入侵地土壤酶活性、土壤微生物群落的影响．结果表明：与非入侵地比较,杂草五爪金龙种群在粤东地区的入侵明显改变了入侵地的土壤生态系统的部分结构与功能,包括显著提高了入侵地土壤中蔗糖酶、脲酶、磷酸酶及硝酸还原酶的活性,其提高幅度均在2倍以上;增加了真菌、自生固氮菌及氨氧化细菌的数量,降低了细菌与反硝化细菌的数量,其改变率均大于20％．土壤酶活性与土壤微生物群落的改变可能导致土壤肥力的变化,因此,五爪金龙成功入侵的土壤微生物学机制有待进一步探讨． 相似文献
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硝化细菌(nitrifying bacteria)是1889年维诺格拉德斯基第一次分离出来的化能自养菌,这是一类能使土壤中的氨或铵盐转化成亚硝酸盐和硝酸盐的具有硝化作用的细菌。一、硝化细菌的种类硝化细菌包括亚硝酸细菌和硝酸细菌两个生理类群,归属于独立的一科,即硝化杆菌科(Nitrobacteraceae)。 1.把氨氧化成亚硝酸的细菌是亚硝酸细菌,分为两类六属: 相似文献
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蚯蚓对温室土壤中不同微生物类群数量的影响 总被引：2，自引：0，他引：2
为了揭示蚯蚓活动对温室土壤中不同微生物类群数量的影响，对接种蚯蚓的温室土壤和露地土壤中微生物的数量进行了初步研究。结果表明：接种蚯蚓显著提高了温室土壤中不同微生物类群的数量。与未接种蚯蚓的处理比较，12月时，温室土壤中细菌增加了24．53％，放线菌增加了39．46％，真菌增加了29．7l％，总量增加了25．8l％；露地土壤中细菌增加了18．18％，放线菌增加了29．45％，真菌增加了16．24％，总量增加了21．14％。4月时，温室土壤中细菌增加了42．7l％，放线菌增加了39．08％，真菌增加了36．92％，总量增加了42．53％；露地土壤中细菌增加了33．69％，放线菌增加了22．29％，真菌增加了20．7l％，总量增加了32．73％。接种蚯蚓的温室土壤中不同微生物类群数量的增幅均高于接种蚯蚓的露地土壤。其中4月时接种蚯蚓后的温室土壤的细菌增加量高于其他处理。 相似文献
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为了揭示蚯蚓活动对温室土壤中不同微生物类群数量的影响,对接种蚯蚓的温室土壤和露地土壤中微生物的数量进行了初步研究.结果表明:接种蚯蚓显著提高了温室土壤中不同微生物类群的数量.与未接种蚯蚓的处理比较,12月时,温室土壤中细菌增加了24.53%,放线菌增加了39.46%,真菌增加了29.71%,总量增加了25.81%;露地土壤中细菌增加了18.18%,放线菌增加了29.45%,真菌增加了16.24%,总量增加了21.14%.4月时,温室土壤中细菌增加了42.71%,放线菌增加了39.08%,真菌增加了36.92%,总量增加了42.53%;露地土壤中细菌增加了33.69%,放线菌增加了22.29%,真菌增加了20.71%,总量增加了32.73%.接种蚯蚓的温室土壤中不同微生物类群数量的增幅均高于接种蚯蚓的露地土壤.其中4月时接种蚯蚓后的温室土壤的细菌增加量高于其他处理. 相似文献
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土壤细菌是土壤微生物的一个重要组成部分,土壤有机碳变化与之密切相关,研究不同环境下土壤细菌特征对提高土壤肥力具有重大意义.本文通过对不同环境土壤细菌进行培养与分析,并研究了其土壤细菌菌落在不同温度、酸度及不同土层深度时细菌菌落的变化.结果表明:不同环境的土壤中,以菜地里的土壤细菌种类和数量最多,为1.0× 108cfu/g,湖边土壤的细菌数量最少,为6.67×107cfu/g.本培养实验表明,大多细菌最适合的生长环境为pH≈7,土层深度为10cm,温度30℃～40℃的条件下.所以,适宜的环境及人为施肥与耕作可以提高土壤的微生物量. 相似文献
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云南西双版纳香荚兰种植园土壤微生物类群初探 总被引：1，自引：0，他引：1
对采自西双版纳香荚兰11个不同种植区土样中的细菌、放线菌和真菌三大微生物类群进行了分析,分离出真菌优势种群14种、细菌31种、放线菌8种。细菌中芽胞杆菌占半数以上,放线菌中金色类群和白孢类群占优势。要从土壤的微生物区系对其病害进行调控,需要进一步摸清优势种群与病害的关系,并从中找出其有拮抗性的优势菌,分析研究诱发其有拮抗性的优势种群条件。 相似文献
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Hg~（2＋）胁迫培养对水生植物根际微生物的影响 总被引：1，自引：0，他引：1
采用水培方法,在实验室条件下,选择不同浓度的Hg2＋对大薸（Pistiastratiote）、慈姑（Sagittaria sagittifolia L）和穗状狐尾藻（Myriophyllum spicatum Linn.）进行胁迫培养,通过测定三种水生植物根系的微生物区系及与氮循环细菌的数量变化,分析三种水生植物根际微生物对重金属Hg2＋的耐受性,微生物区系结构和与氮循环有关的细菌的数量变化。结果发现,Hg2＋胁迫改变了水生植物根系微环境,对微生物区系结构产生明显的影响;氮循环细菌生理类群的数量随着外源重金属Hg2＋浓度变化表现出一定的特殊性和复杂性。 相似文献
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对烟草根系施用5种配方肥料,并分别检测烟草移栽前、后20,40,60,120 d的根际土壤微生物,比较研究了不同肥料对烟草根际微生物的影响．实验结果显示：随着有机肥比例的增加,烟草根际土壤中的真菌、细菌等数量均比不添加有机肥的处理（N0处理）呈增加趋势;其中,50％无机氮＋50％有机氮处理（N3处理）能显著增加烟草根际土壤中的微生物数量,真菌、细菌、霉菌数量分别达到2．46×10^5,2．96×10^8,2．95×10^4个/g ．在烟草种植中,施用50％无机氮＋50％有机氮的有机肥有利于提高烟草根际微生物的数量． 相似文献
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用根箱法分析了受萘污染的菖蒲根际和非根际土壤中微生物指标.结果表明:萘对土壤细菌和放线菌可能起抑制作用,根系泌氧及短时期根系分泌物等可以减弱萘污染的影响,长时间后非根际的环境比根际环境更有利于细菌和放线菌的生长.萘污染严重抑制土壤真菌的生长,植物根系的泌氧和根系分泌物极大地减弱萘污染对真菌的影响.菖蒲的存在有利于微生物的生长. 相似文献
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INTRODUCTIONTheimportanceofmicroorganismstosoilfer tilityandsoilqualityhasbeencommonlyaccept ed (Smithetal.,1 990 ;Brookes,1 995;Da lal,1 998;Wicketal.,1 998) .Soilmicrobialbiomassasanimportantmicrobialpropertyhasbeenextensivelystudiedsinceitisthelivingco… 相似文献
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文章初步探讨了用不同DNA提取方法,对盐土中微生物总DNA的提取效果.实验结果表明,由于盐土中微生物数量较少,溶菌酶-SDS-冻融裂解法、溶菌酶-SDS-蛋白酶K-冻融裂解法均无法提取到盐土中微生物的总DNA;变性剂-SDS-高盐法和试剂盒提取法能获得DNA,但效果不佳;只有用变性剂-SDS-高盐修改法能快速、有效地提取盐土中微生物的基因组DNA. 相似文献
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根的溢泌物与根际微生物关系的研究 总被引：7，自引：0，他引：7
焦海华 《洛阳师范学院学报》2003,22(2):88-90
从山西长治不同区域分布的松树、柏树、苹果树的根际及耕种 2 0年以上的耕地里 ,在不同的季节、不同深度采集土壤样品 .采用稀释混合平板法分离培养和活菌计数 ,研究了根际微生物种群与植物根溢泌活动之间的相互关系 .松树、柏树根际微生物种类和数量 ,在不同季节、不同土壤深度差别不显著 .苹果树根际、耕地土壤中微生物无论从种类和数量上 ,均与季节变化、土壤深度有相关性 相似文献
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Microbial activity and community diversity in a variable charge soil as affected by cadmium exposure levels and time 总被引：1，自引：0，他引：1
Effects of cadmium (Cd) on microbial biomass, activity and community diversity were assessed in a representative variable charge soil (Typic Aquult) using an incubation study. Cadmium was added as Cd(NO3)2> to reach a concentration range of 0～16 mg Cd/kg soil. Soil extractable Cd generally increased with Cd loading rate, but decreased with incubation time. Soil mi-crobial biomass was enhanced at low Cd levels (0.5～1 mg/kg), but was inhibited consistently with increasing Cd rate. The ratio of microbial biomass C/N varied with Cd treatment levels, decreasing at low Cd rate (<0.7 mg/kg available Cd), but increasing progressively with Cd loading. Soil respiration was restrained at low Cd loading (<1 mg/kg), and enhanced at higher Cd levels. Soil microbial metabolic quotient (MMQ) was generally greater at high Cd loading (1～16 mg/kg). However, the MMQ is also affected by other factors. Cd contamination reduces species diversity of soil microbial communities and their ability to metabolize different C substrates. Soils with higher levels of Cd contamination showed decreases in indicator phospholipids fatty acids (PLFAs) for Gram-negative bacteria and actinomycetes, while the indicator PLFAs for Gram-positive bacteria and fungi increased with increasing levels of Cd contamination. 相似文献
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Eleven red soils varying in land use and fertility status were used to examine the effect of land use on microbial biomass-C,-N
and-P. Microbial biomass-C in the red soils ranged from about 68 mg C/kg to 225 mg C/kg, which is generally lower than that
reported from other types of soil, probably because of low organic matter and high acidity in the red soils. Land use had
considerable effects on the amounts of soilC
mic. TheC
mic was the lowest in eroded fallow land, followed by woodland, tea garden, citrus grove and fallow grassland, and the highest
in vegetable and paddy fields. There was significant correlation betweenC
mic and organic matter content, suggesting that the influence of land use onC
mic is mainly related to the input and accumulation of organic matter. Microbial biomass-N in the soils ranged from 12.1 Nmg/kg
to 31.7 Nmg/kg and was also affected by land use. The change ofN
mic with land use was similar to that ofC
mic. The microbial C/N ratio ranged from 5.2 to 9.9 and averaged 7.6. TheN
mic was significantly correlated with soil total N and available N. Microbial biomass-P in the soils ranged from 4.5 mg P/kg
to 52.3 mg P/kg. The microbial C/P ratio was in the range of 4–23. TheP
mic was relatively less affected by land use due to differences in fertilization practices for various land use systems.
Project (No. 40025104) supported by National Outstanding Youth Foundation of China 相似文献
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广西石漠化地区不同植被恢复样地的土壤微生物量比较 总被引：1，自引：0，他引：1
用土壤微生物研究方法和化学分析方法,对广西石漠化地区不同植被恢复样地土壤微生物量碳、氮和磷以及土壤呼吸速率进行测定,从不同植被类型及土壤理化性质等角度,对不同植被恢复调查样地的生态恢复效果进行比较。结果表明:土壤微生物量碳、磷以及土壤呼吸在不同植被样地之间有显著差异;土壤微生物量碳的大小排序为:乔灌混交林青檀任豆青冈侧柏阴香青檀+鞍叶羊蹄甲剑麻枫香湿地松吊丝竹湿地松+桉树桉树光板地;在一定时间范围内,随着植被恢复年限增加,土壤微生物量碳含量逐渐增加,土壤微生物量氮也呈现缓慢增加,但土壤微生物量磷却呈现明显的波动性,出现先升后降现象;土壤微生物量与土壤水分、有机质、含氮量、脲酶活性等土壤肥力因子有较好的相关性;以青檀、侧柏、阴香、任豆等乡土植物为优势种的样地,其土壤微生物量明显大于外来物种湿地松和桉树为优势种的样地。因此,在石漠化地区植被恢复过程中,应首先考虑使用青檀、侧柏、阴香、任豆等乡土树种。 相似文献
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Abundance and composition of ammonia-oxidizing bacteria and archaea in different types of soil in the Yangtze River estuary 总被引：2，自引：0，他引：2
Xiao-ran Li Yi-ping Xiao Wen-wei Ren Zeng-fu Liu Jin-huan Shi Zhe-xue Quan 《Journal of Zhejiang University. Science. B》2012,13(10):769-782
Tidal flats are soil resources of great significance. Nitrification plays a central role in the nitrogen cycle and is often a critical first step in nitrogen removal from estuarine and coastal environments. We determined the abundance as well as composition of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in different soils during land reclamation process. The abundance of AOA was higher than that of AOB in farm land and wild land while AOA was not detected in tidal flats using real-time polymerase chain reaction (PCR). The different abundances of AOB and AOA were negatively correlated with the salinity. The diversities of AOB and AOA were also investigated using clone libraries by amplification of amoA gene. Among AOB, nearly all sequences belonged to the Nitrosomonas lineage in the initial land reclamation process, i.e., tidal flats, while both Nitrosomonas and Nitrosospira lineages were detected in later and transition phases of land reclamation process, farm land and wild land. The ratio of the numbers of sequences of Nitrosomonas and Nitrosospira lineages was positively correlated with the salinity and the net nitrification rate. As for AOA, there was no obvious correlation with the changes in the physicochemical properties of the soil. This study suggests that AOB may be more import than AOA with respect to influencing the different land reclamation process stages. 相似文献