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31.
Laura B. Martínez-García Cristina Armas Juan de Dios Miranda Francisco M. Padilla Francisco I. Pugnaire 《Soil biology & biochemistry》2011,43(3):682-689
Interactions between arbuscular mycorrhizal fungi (AMF) and plants are essential components of ecosystem functioning; however, they remain poorly known in dry ecosystems. We examined the relationship between seven shrub species and their associated AMF community in a semi-arid plant community in southern Spain. Soil characteristics and plant physiological status were measured and related to AMF community composition and genetic diversity by multivariate statistics. We found differences in AMF communities in soils under shrubs and in gaps among them, whereas no differences were detected among AMF communities colonizing roots. Soil nutrients content drove most of the spatial variations in the AMF community and genetic diversity. AMF communities were more heterogeneous in fertile islands with low nitrogen-to-phosphorus ratio and vice versa. AMF genetic diversity increased in soils limited by phosphorus and with high soil organic matter content, while AMF genetic diversity increased in roots growing in soil not limited by phosphorus. Overall, we could not find a clear link between plant performance and the associated AMF community. Our findings show that different shrub species generate islands of fertility which differ in nutrient content and, therefore, support different AMF communities, increasing AMF diversity at the landscape level. 相似文献
32.
天山北坡垂直自然带土壤古菌多样性分析 总被引：1，自引：0，他引：1
[目的]了解天山北坡垂直自然带土壤古菌多样性、优势种群及影响其分布的主要因素.[方法]利用末端限制性片段长度多态性(Terminal Restriction Fragment Length Polymorphism,T- RFLP),对天山北坡垂直自然带(山地荒漠带(H1),山地草原带(H2),山地森林带(H3),亚高山草甸带(H4),高山草甸带(H5),冰雪带(H6))土壤古菌多样性及主要影响因素进行研究.[结果]古菌多样性指数在山地森林带最低,高山草甸带和冰雪带最高;聚类分析表明,山地荒漠带、亚高山草甸带、高山草甸带和冰雪带聚为一类,山地草原带和山地森林带聚为一类;典范对应分析(CCA)表明:香依指数(Shannon index,H)和均匀度指数(Evenness,E)均与C/N,土壤湿度及海拔成正相关,与pH,土壤温度成负相关;T- RFs与pH,全氮,有效磷成正相关.[结论]天山北坡垂直自然带土壤古菌多样性丰富度较低,土壤pH、湿度、全氮及植被类型可能是影响其多样性的关键因素. 相似文献
33.
将60头试验猪随机分为2组,每组3个重复,每个重复10头猪;对照组和试验组分别饲喂基础日粮和添加0.2%复方陈皮粉的日粮,共计60 d;饲喂过程中定期采集新鲜粪便,采用变性梯度凝胶电泳(DGGE)和末端限制性内切酶片段长度多态性(T-RFLP)指纹图谱技术研究饲喂复方陈皮粉对猪胃肠道菌群多样性的影响.结果表明,试验期间试验组的猪基本不腹泻,对照组有部分猪经常腹泻.分别对两组粪便样品的胃肠道微生物进行16S rDNA V3区扩增,再通过DGGE技术进行条带分离,DGGE图谱显示,猪胃肠道菌群物种丰富,两组样品之间存在明显的条带差异.对两组粪便样品胃肠道微生物16S rDNA全长进行扩增,用MspⅠ和HaeⅢ对扩增产物进行限制性酶切,再运用T-RFLP技术检测.通过RDP数据库查询比对,在两组粪便样品中,相同的T-RFs片段有27个,相对于试验组,对照组样品中差异部分片段对应的菌种多为致病菌.研究结果表明,临床上使用复方陈皮粉能有效预防猪腹泻等胃肠道疾病,这可能与药物能改善胃肠道微生态坏境,调节菌群平衡有关. 相似文献
34.
生防菌哈茨木霉T4对黄瓜根围土壤细菌群落的影响 总被引：4，自引：0，他引：4
【目的】评价生防菌哈茨木霉（Trichoderma harzianum）T4 对根围土壤细菌群落的影响,为生防菌田间应用的生态安全提供依据。【方法】结合DGGE技术与T-RFLP方法,综合考察引入生防菌哈茨木霉T4后黄瓜根围土壤细菌群落变化。【结果】在引入生防菌的14-56 d内（黄瓜整个生育期）,木霉对根围土壤细菌群落可产生显著影响,并持续一段的时间,随后逐渐减弱。表现为对蓝细菌、β-变形细菌、葡萄球菌、伯克霍尔德菌、沙雷氏菌、酸杆菌和一些不可培养细菌的有效抑制作用,对芽孢杆菌、土壤杆菌、芽单胞菌的明显促进作用。但到70 d时,即收获后2周,检测不到木霉对细菌群落影响。【结论】DGGE和T-RFLP序列分析技术相结合研究生防菌对土壤细菌群落的影响,既能全面描述土壤细菌群落结构变化,还可以初步定性描述变化细菌的种类信息。生防菌哈茨木霉T4的引入对土壤细菌群落产生短期影响,不会长期对土壤细菌群落稳定构成威胁。 相似文献
35.
Hanna Friberg Véronique Edel-Hermann Nadine Gautheron Vincent Faloya Christian Steinberg 《Soil biology & biochemistry》2009,41(10):2075-7890
Two fungal plant pathogens, Rhizoctonia solani AG 2-2 and Fusarium oxysporum f.sp. lini, were studied in relation to general responses of soil fungi and bacteria following incorporation of Brassica juncea. Our aim was to understand to what extent the changes in the biological and physicochemical characteristics of the soil could explain the effects on the studied pathogens and diseases, and to determine the temporal nature of the responses. Short-term effects of mustard incorporation (up to 4 months) were investigated in a microcosm experiment, and compared with a treatment where composted plant material was incorporated. In a field experiment, the responses were followed up to 11 months after removal or incorporation of a mustard crop. In general, responses in the variables measured changed more after incorporation of fresh mustard material than after addition of similar amounts of composted plant material (microcosms) or after removal of the mustard crop (field). The soil inoculum potential of R. solani AG 2-2 decreased directly after incorporation of mustard, but increased later to disease levels above those in the untreated soil. Neither of these effects could be explained by changes in the population density of R. solani AG 2-2. Fusarium spp. were less influenced, although an increase in the suppressiveness to Fusarium wilt was observed after mustard incorporation as compared with the treatment where mustard was removed. The microbial responses to mustard incorporation were more pronounced for bacteria than for fungi. After an initial substantial increase, the bacterial density decreased but remained above the levels in the control treatment throughout the experimental periods. The bacterial community structure was modified up to 8 months after mustard incorporation. We conclude that incorporation of fresh mustard influences soil microbial communities, especially the bacteria, and has a potential to control the pathogenic activity of R. solani 2-2 on a short-term perspective. The time dependency in microbial responses is important and should be taken into consideration for the evaluation of the potential of Brassicas to control plant disease on a field scale. 相似文献
36.
为探讨解磷微生物菌肥对香蕉土壤根际微生态的影响,利用T-RFLP(terminal restriction fragment length polymorphism)技术分析土壤均匀度指数、香农指数和优势种群等分析微生物多样性,研究高效解磷菌剂与化学磷肥的不同组合施用方式对香蕉植株的生长情况和根际土壤微生物物量和群落结构的影响。结果显示,与对照CK相比,T处理组香蕉苗较CK组生长健壮,地上部分鲜重平均值为42.2 cm,明显比CK高出35.2%。接M-3-01解磷细菌处理组T1、T3生长势最为显著(P0.05),其中,T3株高和茎围分别是CK的1.26、1.16倍。T-RFLP技术分析微生物多样性表明,T1、T3多样性指数和均匀度指数指标分别为2.12/2.11和0.93/0.88,与CCK差异性不明显,但略微高于CK。同时,分析土壤优势种群,处理组T1、T3处理组土壤优势微生物种群数分别为12和14,数目基本与处理前土壤CCK的一致,而T2略低于CK。拟柱孢藻(Cylindrospermopsis)和北里孢菌(Kitasatospora)只存在于CK和施用解磷菌剂T1、T3处理土壤中。土壤种植香蕉苗后,不同施用方式对土壤微生物群落丰富度和多样性的稳定具有积极影响。因此,施用高效解磷菌剂对维持土壤微生物群落丰富度和均匀度效果较好。 相似文献
37.
【目的】研究长期不同施肥处理对水稻土厌氧氨氧化细菌(anaerobic ammonium oxidation bacteria,AAOB)群落结构和垂直分布特征的影响,深入认识不同施肥处理下石灰性紫色水稻土厌氧氨氧化作用的微生物调控机制,为该地区科学施肥、培肥地力提供理论依据。【方法】利用化学分析、末端限制性片段长度多态性分析(T-RFLP)和荧光定量PCR技术分别对不同施肥处理下石灰性紫色水稻土理化性质、厌氧氨氧化细菌丰度及群落结构进行分析。【结果】理化性质结果显示,相对于无肥处理(CK),氮(N)、氮磷钾肥(NPK)及氮磷钾配施农家肥(NPKM)均会降低土壤p H和硝态氮含量,而增加土壤有机质、全氮和铵态氮含量。随土壤深度增加,土壤p H增加,全氮和硝态氮含量降低,铵态氮含量变化趋势不明显。q PCR结果显示,就土壤层次而言,厌氧氨氧化细菌在0—20 cm层的丰度最高,20—40 cm层最低;就施肥处理而言,氮肥(N)对厌氧氨氧化细菌的丰度促进最为明显。T-RFLP结果表明,厌氧氨氧化细菌在0—20 cm土层群落组成最为丰富,Shannon-wiener多样性指数最高;寡氮肥下其群落组成最为简单,无肥处理下群落结构最为复杂。厌氧氨氧化细菌优势种群属于Candidatus Brocadia。冗余梯度分析(RDA)显示,p H影响是石灰性紫色水稻土厌氧氨氧化细菌群落结构差异的主要环境因子。【结论】本研究显示寡氮处理会降低石灰性紫色水稻土中厌氧氨氧化细菌的多样性但促进其丰度。表层土(0—20 cm)是厌氧氨氧化细菌分布的主要层次。 相似文献
38.
不同作物间作对黄瓜病害及土壤微生物群落多样性的影响 总被引：22，自引：1，他引：22
分别采用RAPD和T-RFLP技术,研究了小麦、毛苕子和三叶草分别与黄瓜间作对黄瓜病害、黄瓜根际土壤微生物群落多样性和黄瓜产量的影响。结果表明,小麦、毛苕子与黄瓜间作均能提高黄瓜根际土壤微生物群落多样性,其中,小麦-黄瓜间作对黄瓜根际土壤微生物群落多样性的影响最为突出;3种作物分别与黄瓜间作均显著提高了黄瓜产量(p<0.01),其中小麦-黄瓜间作的产量优势最强;同时,3种作物分别与黄瓜间作均降低了黄瓜角斑病、白粉病、霜霉病和枯萎病的病情指数和尖孢镰刀菌的数量。间作有利于提高土壤微生物群落的多样性、减轻病害、提高黄瓜产量。 相似文献
39.
马铃薯连作栽培对土壤微生物多样性的影响 总被引：4，自引：2，他引：4
马铃薯是宁夏回族自治区南部山区重要的粮菜兼用作物,随栽培面积持续扩大,轮作倒茬困难,由此带来的连作障碍问题日渐突出。为探明马铃薯连作障碍机制,分别采集马铃薯正茬、连作1年、6年和10年的根际土壤样本,利用末端标记限制性片段长度多态性(terminal restriction fragment length polymorphism,T-RFLP)技术研究连作栽培对根际土壤微生物多样性的影响,以期揭示马铃薯根际土壤主要菌群动态变化规律及连作障碍的可能原因。结果表明:连作栽培后马铃薯土壤细菌和真菌DNA仍具有较高的T-RFLP多态性,但不同连作年限根际土壤中优势T-RFs片段发生变化,多年连作使某些T-RFs消失;随连作年限增加,根际土细菌Shannon-Wienen指数、Simpson指数和Sorenson指数下降,而真菌Shannon-Wienen指数和Simpson指数上升。菌群分析发现,土壤细菌中以厚壁菌门(Firmicutes)芽孢杆菌纲(Bacilli)和梭菌纲(Clostridia)所占比例最大。连作使细菌和真菌菌群发生变化,芽孢杆菌纲、鞘氨醇纲(Sphingobacteria)等比例下降甚至消失,β-变形菌纲(Beta proteobacteria)和异常球菌纲(Deinococci)比例上升;土壤真菌中座囊菌纲(Dothideomycetes)煤炱目(Capnodiales)随连作年限增加比例下降,粪壳菌纲(Sordariomycetes)肉座菌目(Hypocreales)随连作年限增加比例上升。马铃薯连作使根际土壤中芽孢杆菌属(Bacillus)等有益菌属的细菌减少,罗尔斯通菌属(Ralstonia)等致病菌属的细菌增加。连作导致马铃薯根际土壤细菌多样性水平降低,真菌多样性水平升高,根际土壤微生物多样性存在明显差异,连作破坏了根际土壤微生物群落的平衡,使其根际土壤微生态环境恶化。连作障碍可能是多因素综合互作用的结果,持续的研究有利于做出较合理的解释。 相似文献
40.
为了研究氮素转化菌对茶树根际土壤微生态环境的影响,本试验以山东泰安2年生茶树根际土壤为研究对象,设置枯草芽孢杆菌（T1）和褐球固氮菌（T2）两个接种处理,以不接种为对照（CK）。采用培养计数法与末端限制性片段长度多态性技术（T-RFLP）,测定不同时期根际土壤中细菌、真菌、放线菌、氨化细菌、固氮菌、硝化细菌的数量及接种后微生物多样性的变化。同时测定接种后土壤中养分含量的变化。结果表明,接种60βd后T1和T2处理细菌数量显著高于CK,但对真菌及放线菌的影响不显著。整个试验过程氨化细菌和固氮菌数量高于CK,氨化细菌以T1处理最多,固氮菌以T2处理最多,硝化细菌数量始终是CK显著高于T1和T2处理。基于T-RFLP图谱分析,与对照组相比,菌剂组均增加了土壤微生物多样性和丰富度,各物种在数量上的均匀程度变大。在土壤养分方面,T1、T2菌剂处理组铵态氮浓度显著高于对照组,硝态氮含量低于对照。在速效P方面,T1、T2含量比CK分别显著提高了8%、25%。在速效K方面,T1、T2含量显著高于CK,提高了15%和11%。枯草芽孢杆菌和褐球固氮菌菌剂改善了茶树根际土壤微生态环境,提高了土壤养分,表现出正面效应,是一种生态安全性较高的生物菌剂。 相似文献