秸秆直接还田与炭化还田对潮土硝化微生物的影响   总被引：1，自引：0，他引：1  

李培培  仝昊天  韩燕来  姜瑛  吴传发 《土壤学报》2019,56(6):1471-1481

为比较秸秆直接还田和炭化还田对黄淮海平原小麦/玉米轮作体系典型潮土硝化作用及硝化微生物群落的影响,设置4个处理:全量小麦秸秆还田(S)、全量秸秆炭化还田(B)、半量秸秆半量生物质炭还田(SB)和不进行秸秆或生物质炭还田的对照(CK),连续进行3 a田间试验。对小麦、玉米两个生长季土壤理化性质进行分析,用末端限制性片段长度多态性(Terminal-restriction length polymorphism,T-RFLP)技术和克隆文库技术对氨氧化古菌(Ammonia-oxidizing archaea,AOA)和氨氧化细菌(Ammonia-oxidizing bacteria,AOB)群落结构和多样性进行分析。结果表明,在小麦季,与S处理相比,B处理显著降低了土壤容重,提高了土壤pH、有机碳(SOC)和速效钾(AK)含量(P0.05),但并未显著影响土壤水分、铵态氮(NH_4~+-N)和硝态氮(NO_3~--N)含量;B和SB处理的硝化潜势(Potential nitrification rate,PNR)分别为0.58、0.49μg·h~(-1)·g~(-1)(以NO_2~-计,下同),显著高于CK,与S处理(0.40μg·h~(-1)·g~(-1))差异不显著。玉米季,B处理显著提高了土壤水分、SOC和AK(P0.05),各处理玉米季的PNR整体低于小麦季,B处理最高(0.27μg·h~(-1)·g~(-1)),显著高于CK和S处理(P0.05)。小麦季PNR分别与AK、NH_4~+浓度和土壤容重显著相关(P0.05),与AOA和AOB群落组成均无显著关系;玉米季PNR仅与理化因子SOC显著相关,但该季节PNR与AOB群落结构显著相关。冗余分析(RDA)表明,土壤SOC、容重、pH和AK是显著影响硝化微生物群落结构的主要因子,对AOA和AOB群落结构总变异的解释量分别为76.4%和75.5%。系统发育树分析表明,AOA大部分属于土壤古菌Group1.1b,AOB多属于亚硝化螺菌Nitrosospira簇3。综上,与秸秆直接还田相比,炭化还田提高土壤硝化活性,改善部分土壤理化性质,引起土壤硝化微生物群落结构变化。  相似文献   

改进AOA模式的大田农机无人驾驶导航参数检测系统设计   总被引：1，自引：1，他引：0  

解彬彬  刘继展  何蒙  蔡连江  徐朱洁  崔冰波 《农业工程学报》2021,37(14):40-51

卫星导航、视觉导航和雷达导航的成本昂贵、系统构成复杂和适用作业场景有限,在生产特征呈现区域化、适度小规模和分布零散的国内南方水田难以实现便捷跨区域作业和无法适用多农业场景。针对上述问题,该研究以大田环境下无人驾驶农机的牛耕式往复作业路径模式为背景,提出了改进AOA(信号到达角度,Angle-of-Arrival)模式的农业机械无人驾驶导航参数检测系统。该系统采用UWB(超宽带通信,Ultra Wide Band)基站-标签作为检测传感器,设计了TBZ(田边双基站-车身纵向双标签)和TBH(田边双基站-车身横向双标签)2种传感器布置方式,实现农业机械无人驾驶过程中导航参数的快速精准检测。静态试验结果表明:对于2种传感器布置方式,在固定的基站间距和标签间距下,随着标签间距或基站间距的增大导航参数检测精度均有所提高,横向偏差检测误差≤8 cm,航向偏差趋近于0,但不大于1°,并通过正交组合试验方差分析明确了2种传感器布置方式的关键参数对横向偏差和航向偏差检测精度影响的显著性,确定了主次因素和较优参数组合。动态试验结果表明:随着车速增大,横向偏差和航向偏差的检测精度有所降低,横向偏差误差均不超过10 cm,航向偏差的检测误差均小于3°,变异系数均小于10%,说明动态环境下自主导航参数检测系统仍具有较高的检测精度,可满足农机大田自主导航作业需求。研究结果可为研制低成本、高精度和便捷的无人驾驶系统提供参考。  相似文献   

大庆龙凤湿地底泥氨氧化细菌与氨氧化古菌多样性分析     

马茹霞  晏磊  王国兴  王长虹  贾军  邓兵  沈婷婷  王伟东 《黑龙江八一农垦大学学报》2015,(2):69-73,78

为研究湿地底泥中氨氧化细菌(Ammonia-Oxidizing Bacteria,AOB)与氨氧化古菌(Ammonia-Oxidizing Archaea,AOA)的群落多样性,构建AOB与AOA的amo A基因克隆文库,同时利用限制性片段长度多态性(RFLP)技术将克隆文库阳性克隆子进行归类并测序。结果发现,从湿地底泥中均得到3个AOB与AOA的可操作分类单元(OTU)。其中,所有的AOB均属于亚硝化单胞菌属(Nitrosomonas),而AOA属于泉古菌门(Crenarcharota),与河口沉积物等环境中获得的序列具有较高同源性。  相似文献   

A non-ACC pathway for ethylene biosynthesis in Botrytis cinerea     

Altaf QadirErrol W. Hewett  Peter G. LongDavid R. Dilley 《Postharvest Biology and Technology》2011,62(3):314-318

Premature softening and tissue senescence occur in kiwifruit infected with Botrytis cinerea. While ethylene production is enhanced in infected fruit and B. cinerea produces ethylene on defined media in vitro the source of ethylene in this pathosystem is unclear. Ethylene production by B. cinerea was enhanced when methionine or ∝-keto-methylthiobutyric acid (KMBA) was added to a defined (modified Pratts) medium. Although 1-aminocyclopropane-1-carboxylic acid (ACC) did not stimulate ethylene production, ∝-aminooxyacetic acid (AOA) was inhibitory suggesting a role for a pyridoxal phosphate mediated enzyme reaction down stream from the methionine/KMBA stimulated ethylene biosynthetic pathway. Cobalt chloride (Co²⁺) was inhibitory, but after a 4-d lag period ethylene production from B. cinerea cultures containing methionine and Co²⁺ reached the same level as those without Co²⁺. [U ¹⁴C] methionine was converted to ¹⁴C-ethylene with high efficiency indicating that it is a direct precursor, while [2,3 ¹⁴C]-ACC did not yield radioactively labelled ethylene. These results suggest that the ethylene biosynthetic pathway in B. cinerea does not involve ACC as a precursor and that the enzyme responsible for synthesising ethylene is similar to, but different from, ACC oxidase from higher plants. The ethylene biosynthetic pathway in B. cinerea is yet to be determined.  相似文献   

Linking plant identity and interspecific competition to soil nitrogen cycling through ammonia oxidizer communities     

Fenliang Fan  Fusuo Zhang 《Soil biology & biochemistry》2011,43(1):46-54

Both plants and microbes influence soil nutrient cycling. However, the links between plants, microbes and nutrient cycling are poorly understood. In this study, we investigated how plant identity and interspecific competition influence soil nitrogen cycling and attempted to link plant identity and interspecific competition to community structures of bacterial and archaeal ammonia oxidizers based on terminal restriction fragment length polymorphism analysis (T-RFLP) of bacterial and archaeal ammonia monooxygenase (amoA) genes. Faba bean and maize monocultures and a faba bean/maize mixture were planted with two nitrogen levels (0 and 100 mg N kg⁻¹ soil as urea). Soil mineral nitrogen, ammonia oxidizer function (potential nitrification activity, PNA) and community structures were measured 28 and 54 days after plant emergence. Faba bean and maize substantially differed in their influences on mineral nitrogen concentrations and PNA in rhizosphere soils. Soil mineral nitrogen and PNA in the rhizosphere soils of the faba bean/maize mixture were closer to those of the maize monoculture than to those of the faba bean monoculture. T-RFLP with restriction enzymes BsaJI and Hpy8I distinguished variations in bacterial and archaeal ammonia oxidizers community structure, respectively, and detected both between-cluster and within-cluster variations in bacterial ammonia oxidizers. T-RFLP data showed that nitrogen addition favored part of a Nitrosospira cluster 3b sequence type and suppressed part of a cluster Nitrosospira 3a sequence type of bacterial ammonia oxidizers, while it had no influence on the archaeal ammonia oxidizer community structure. Although multivariate analysis showed that the function and community structure of bacterial ammonia oxidizers were significantly correlated, plant species and interspecific competition did not significantly change the community structure of bacterial and archaeal ammonia oxidizers. These results indicate that plant species and interspecific competition regulate soil nitrogen cycling via a mechanism of other than alteration in the community structure of ammonia oxidizers as investigated by DNA based methods.  相似文献   

脲酶抑制剂与硝化抑制剂对稻田土壤硝化、反硝化功能菌的影响   总被引：4，自引：2，他引：2  

张文学  王少先  夏文建  孙刚  刘增兵  李祖章  刘光荣 《植物营养与肥料学报》2019,25(6):897-909

[目的]在农业生产中,脲酶抑制剂(urease inhibitor,UI)与硝化抑制剂(nitrification inhibitor,NI)常作为氮肥增效剂来提高肥料利用率。本文研究了在我国南方红壤稻田施用脲酶抑制剂与硝化抑制剂后,土壤中氨氧化细菌(ammonia oxidizing bacteria,AOB)、氨氧化古菌(ammonia-oxidizing archaea,AOA)以及反硝化细菌的丰度以及群落结构的变化特征,旨在揭示抑制剂的作用机理及其对土壤环境的影响。[方法]试验在我国南方红壤稻田进行,共设5个处理:1)不施氮肥(CK);2)尿素(U);3)尿素+脲酶抑制剂(U+UI);4)尿素+硝化抑制剂(U+NI);5)尿素+脲酶抑制剂+硝化抑制剂(U+UI+NI),3次重复。脲酶抑制剂与硝化抑制剂分别为NBPT[N-(n-butyl)thiophosphrictriamide,N-丁基硫代磷酰三胺]和DMPP(3,4-dimethylpyrazole phosphate,3,4-二甲基吡唑磷酸盐)。通过荧光定量PCR(Real-time PCR)研究水稻分蘖期与孕穗期抑制剂对三类微生物标记基因拷贝数的影响,并分析土壤铵态氮、硝态氮与三种菌群丰度的相关性;利用变性梯度凝胶电泳(DenaturingGradient Gel Electrophoresis,DGGE)分析抑制剂对土壤AOB、AOA以及反硝化细菌群落结构的影响,并对优势菌群进行系统发育分析。[结果]1)荧光定量PCR结果表明,施用氮肥对两个时期土壤中AOB的amoA基因与反硝化细菌nirK基因的拷贝数均有显著提高,而对AOA的amoA基因始终没有明显影响;AOB与nirK反硝化细菌的丰度与两个时期的铵态氮含量、分蘖期的硝态氮含量呈极显著正相关,与孕穗期的硝态氮含量相关性不显著;DMPP仅在分蘖期显著减少了AOB的amoA基因拷贝数,表明DMPP主要通过限制AOB的生长来抑制稻田土壤硝化过程;NBPT对三类微生物的丰度无明显影响;2)DGGE图谱表明,在分蘖期与孕穗期,施用氮肥均明显增加了图谱中AOB的条带数,而对AOA却没有明显影响;氮肥明显增加了孕穗期反硝化细菌的条带数;与氮肥的影响相比,抑制剂NBPT与DMPP对AOA、AOB以及反硝化菌的群落结构影响甚微;系统发育分析结果表明,与土壤中AOB的优势菌群序列较为接近的有亚硝化单胞菌和亚硝化螺菌。[结论]在南方红壤稻田中,施入氮肥可显著提高AOB与反硝化细菌的丰度,明显影响两种菌群的群落结构,而AOA较为稳定;NBPT对三类微生物的群落结构丰度无明显影响;硝化抑制剂DMPP可抑制AOB的生长但仅表现在分蘖期,这可能是其缓解硝化反应的主要途径;这也说明二者对土壤生态环境均安全可靠。  相似文献   

东北沼泽湿地土壤中氨氧化微生物活性和丰度研究   总被引：1，自引：1，他引：0  

谢月  梁红  宋立全  王清波  付东风  高大文 《农业环境科学学报》2018,37(3):546-551

为了研究东北典型沼泽湿地——三江湿地和扎龙湿地表层土壤中氨氧化微生物的活性和丰度,采用氯酸盐抑制亚硝酸盐氧化菌(Nitrite-oxidizing bacteria,NOB)和氨苄青霉素抑制氨氧化细菌(Ammonia-oxidizing bacteria,AOB)以及荧光定量PCR的方法,分析了生长季和非生长季氨氧化微生物的活性和丰度的关系。结果表明:在不同类型的湿地土壤中,pH值显著地影响湿地土壤中氨氧化古菌(Ammonia-oxidizing archaea,AOA)的潜在氨氧化活性(Potential ammonia oxidation activity,PAO)(P0.01)。AOA的丰度值与PAO_(AOA+AOB)呈显著正相关(r=0.96,P0.05),而与PAO_(AOA)不存在相关性(P0.05)。三江湿地的毛苔草和小叶章土壤中的PAO_(AOA+AOB)、PAO_(AOA)、AOA丰度与AOB丰度,并无显著差异。研究表明植被的差异并没有影响土壤中氨氧化微生物的潜在氨氧化活性以及氨氧化微生物的丰度,但在抑制AOB活性之后毛苔草土壤中的PAO出现了显著的下降(P0.05),表明AOB在毛苔草土壤中的氨氧化过程中发挥着重要作用。  相似文献   

三种硝化抑制剂抑制土壤硝化作用比较及用量研究   总被引：16，自引：4，他引：12  

王雪薇  刘涛  褚贵新 《植物营养与肥料学报》2017,23(1):54-61

【目的】硝化抑制剂是调控土壤氮素转化与硝化作用微生物群落结构的有效途径。本文通过室内模拟试验对3种硝化抑制剂在不同剂量下的硝化抑制效果进行研究,旨在筛选出效果最佳的剂型与剂量,为石灰性土壤硝化抑制剂的合理应用提供依据。 【方法】培养试验在生长箱内进行,25℃黑暗条件培养;盆栽试验在温室内进行。供试硝化抑制剂为双氰胺（DCD）、3,4-二甲基吡唑磷酸盐（DMPP）和2-氯-6-三氯甲基吡啶（Nitrapyrin）,DCD和DMPP用量均设定为纯氮（N）量的0（CK）、1.0%、2.0%、3.0%、3.5%、4.0%、4.5%、5.0%、6.0%和7.0%;Nitrapyrin用量分别为纯氮量的0、0.1%、0.125%、0.2%、0.25%、0.3%、0.35%、0.4%、0.45%和0.5%,三种硝化抑制剂均设10个水平,每个水平3次重复。盆栽试验氮加入量为每公斤风干土0.50 g,三种硝化抑制剂用量分别为纯氮用量的5%、1%、0.648%。调查比较了三者的硝化抑制效果及对土壤氮素转化的影响及其对小青菜鲜重的生物学效应;采用变性梯度凝胶电泳（DGGE）法分析了不同硝化抑制剂对土壤AOA、AOB群落结构的影响。 【结果】DCD、DMPP、Nitrapyrin均可显著抑制土壤硝化作用（P＜0.05）,各硝化抑制剂处理土壤的NH₄+-N含量分别较对照提高了46.2~256.1 mg/kg、291.8~376.7 mg/kg、3.68~372.9 mg/kg。DCD与DMPP处理的硝化抑制率分别为49.3%~79.4%和96.4%~99.4%,DCD表现出明显的剂量效应,但DMPP在1%~7%浓度范围内的剂量效应不明显。Nitrapyrin在0.1%~0.2%浓度范围内有明显的剂量效应。0.25%~0.5% Nitrapyrin的硝化抑制率为98.9%~99.9%,其硝化抑制效果与DMPP处理相同。DCD、DMPP、Nitrapyrin处理的小青菜地上部分鲜重分别比氮肥处理（ASN）提高了12.7%、11.1%、17.6%。施用硝化抑制剂可改变土壤AOA和AOB群落结构,且对AOA群落结构的影响大于AOB,不同硝化抑制剂之间对AOA和AOB群落结构的影响无差异。 【结论】3种硝化抑制剂的硝化抑制效果表现为Nitrapyrin≥DMPP>DCD,均对AOA与AOB群落结构产生明显影响。各硝化抑制剂处理均可提高小青菜地上部鲜重、叶片Vc含量及可显著提高小青菜叶片氨基酸含量（P＜0.05）。综合比较,Nitrapyrin硝化抑制效果好于DMPP,DCD效果最差,推荐用量为基于纯氮0.25%的Nitrapyrin添加量。  相似文献   

农田土壤好氧氨氧化和甲烷氧化交互作用机制的研究进展          下载免费PDF全文

潘红  李江叶  冯浩杰  娄燕宏  杨全刚  王会  诸葛玉平 《西北农业学报》2024,(2):201-207

从农田土壤生态系统中硝化和甲烷氧化的研究意义、氨氧化和甲烷氧化的功能微生物演替规律，以及二者交互作用机制三个方面综述了现阶段取得的主要研究成果，并进一步阐述了土壤碳氮元素生物地球化学循环机制研究的科学问题和面临的挑战。未来研究应充分利用学科交叉，结合宏观结果和土壤微观动态过程，揭示土壤中不可培养微生物代谢能力及其在土壤生物地球化学循环中的重要作用，逐步实现对土壤生态过程的预测和调控。  相似文献   

Identifying response groups of soil nitrifiers and denitrifiers to grazing and associated soil environmental drivers in Tibetan alpine meadows     

《Soil biology & biochemistry》2014

Defining response groups within N-related microbial communities is needed to predict land management effect on soil N dynamics, but information on such response groups and associated environmental drivers is scarce. We investigated the abundance and major populations of ammonia-oxidizing archaea (AOA) and bacteria (AOB), and nirS- and nirK-harboring denitrifiers under different grazing managements in Tibetan alpine meadow soils. Grazing increased AOB and AOA abundances up to 42 fold and 3.7 fold, respectively, and increased the percentage of AOB within total ammonia oxidizers from 3.1% to 10.8%. The abundance of nirK-like denitrifiers increased with grazing intensity, while the abundance of nirS-like denitrifiers tended to decrease. However, sub-groups within each of these broad groups of (de)nitrifiers responded differently to grazing. Soil nitrate was the main driver of the abundance of denitrifier sub-groups (nirK or nirS) positively responding to grazing, while soil moisture and carbon concentration were the main drivers of the abundance of denitrifier sub-groups negatively responding to grazing. AOB and nirK-harboring denitrifiers thus generally responded more positively to grazing than AOA and nirS-harboring denitrifiers, but significant functional diversity existed within each group. Our approach demonstrates the usefulness of the concept of response groups to better characterize and understand (de)nitrifier response to grazing.  相似文献