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灯盏花乙素(scutellarin,Scu)具有清热解毒、扩张心脑血管、改善微循环等作用。通过观察不同浓度Scu对猪肾小管上皮细胞(pig kidney proximal tubular,LLC-PK1)热休克蛋白72(heat shock protein72,HSP72)、B细胞淋巴瘤/白血病-2(B-cellymphoma/leukemia-2,Bcl-2)及Bcl-2相关X蛋白(Bcl-2associated X protein,Bax)表达的影响,探讨灯盏花乙素提高细胞耐热性的可能机制。将培养的LLC-PK1细胞随机分为37℃空白对照(Ⅰ组),42℃单纯热应激1 h(Ⅱ组),以及分别用不同浓度(1×10-5、1×10-6和1×10-7mol/L)Scu处理并42℃热应激1 h组(分别为Ⅲ、Ⅳ和Ⅴ组),提取各组细胞总RNA和总蛋白,用实时荧光定量PCR和Western blot分别检测HSP72、Bcl-2和Bax基因及蛋白的表达量。结果显示,与Ⅰ组相比,Ⅱ组LLC-PK1细胞HSP72和Bax的mRNA及蛋白表达量显著升高(P0.05),Bcl-2/Bax mRNA和蛋白比值显著降低(P0.05),Bcl-2 mRNA和蛋白表达量并无显著差异(P0.05)。与Ⅱ组相比,Ⅳ和Ⅴ组LLCPK1细胞HSP72 mRNA和蛋白的表达量均显著升高(P0.05),Ⅲ组无显著差异(P0.05);Ⅳ组细胞Bcl-2 mRNA和蛋白表达量均显著升高(P0.05),Ⅲ和Ⅳ组并无显著差异(P0.05);Ⅲ、Ⅳ和Ⅴ组Bax mRNA和蛋白表达量均显著降低(P0.05);Ⅳ和Ⅴ组Bcl-2/Bax蛋白比值显著升高(P0.05)。研究结果表明,热应激条件下Scu可诱导LLC-PK1细胞HSP72表达,提高Bcl-2/Bax比值。结果提示,Scu可增强细胞的抗热休克作用。本研究丰富了体外培养细胞热应激反应的理论,为在实践中增加细胞抗热休克能力提供了理论依据。 相似文献
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HSP60对动物的睾丸发育、精子发生起着重要的调控作用。支持细胞是睾丸内唯一与生精细胞直接发生联系的体细胞,对精子发生、成熟等过程有直接影响。为研究HSP60对白牦牛睾丸支持细胞增殖的调控作用,本试验通过组合酶消化法分离培养白牦牛原代支持细胞,通过差速贴壁法和Tris-HCL低渗缓冲液进行纯化处理,运用免疫荧光染色和Feulgen染色鉴定细胞,经流式细胞仪检测得到96.2%高纯度支持细胞。构建HSP60过表达载体p IRES2-EGFP-HSP60,合成靶向siRNA沉默HSP60,瞬时转染支持细胞后,经qPCR检测发现过表达组HSP60 mRNA在24、48、72 h等时间点均上调,沉默组HSP60 mRNA在24、48、72 h等时间点均下调。MTS试验检测细胞的增殖情况,过表达HSP60组中的支持细胞增殖效率各时间点均显著高于空白对照组和空质粒组;沉默HSP60组中支持细胞的增值率各时间点均低于空白对照组和阴性对照组,但差异不显著。qPCR检测细胞增殖标志基因细胞周期蛋白D1(cyclin D1)和增殖细胞核抗原(PCNA),结果表明,过表达HSP60组的cyclin D1基因在48 h时的表达显著高于空白对照组和空质粒组,PCNA基因的表达在24、48、72 h时均显著高于空白对照组和空质粒组;沉默HSP60组cyclin D1基因和PCNA基因的表达在24、48、72 h时均低于空白对照组和阴性对照组,但差异不显著。综上,HSP60在白牦牛睾丸支持细胞增殖调控中的作用是正向调控。本试验结果为进一步研究HSP60对白牦牛睾丸发育和精子发生的影响奠定了理论基础。 相似文献
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黄芩苷(baicalin)具有清热镇静、抑菌抗炎等作用,通过不同浓度黄芩苷对热应激下睾丸支持细胞(sertoli cells,SCs)表达胶质细胞源性神经生长因子(glial cell line-derived neurotrophic factor,GDNF)和干细胞因子(stem cell factor,SCF)的影响,探讨黄芩苷是否可以通过提高SCs的耐热性保护细胞,提高SCF与GDNF的表达。采用二步酶消化法分离犊牛(Bos taurus)睾丸组织获得SCs,4 h差速贴壁纯化,分别采用RT-PCR鉴定标志性基因GDNF和SCF的表达,福尔根染色鉴定细胞形态。选用第3代对数生长期的SCs,通过噻唑蓝(methyl thiazoletetrazolium,MTT)筛选黄芩苷安全使用浓度;设对照组(37℃)、42℃单纯热应激组和42℃热应激加黄芩苷(0.1,1,10和20μg/m L)组;用MTT检测细胞存活率,提取各组细胞总RNA和总蛋白,分别用实时荧光定量PCR(Real-time quantitative PCR,q RT-PCR)和酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)检测GDNF和SCF m RNA及其蛋白的表达。结果显示,第3代原代细胞生长良好,RT-PCR检测可见GDNF和SCF m RNA表达,福尔根染色显示有卫星核小体存在,表明分离培养的细胞为SCs。对第3代SCs进行热应激处理,与对照组(37℃)比较,42℃单纯热应激组细胞存活率极显著(P<0.01)下降,GDNF和SCF m RNA(P<0.01)与蛋白(P<0.05)的表达也降低。与42℃单纯热应激组比较,用浓度为1μg/m L(P<0.05)和10μg/m L(P<0.01)黄芩苷作用细胞的存活率升高;浓度在0.1~20μg/m L黄芩苷作用的细胞,其GDNF和SCF m RNA的表达量均极显著(P<0.01)高于42℃单纯热应激组,而在黄芩苷浓度为1μg/m L时,SCF(P<0.01)和GDNF(P<0.05)蛋白表达量高于42℃单纯热应激组,并且基因和蛋白的表达量随着黄芩苷浓度的增加呈现先上升后下降的趋势。结果表明,黄芩苷能提高热应激下SCs的存活率以及GDNF和SCF的表达量。本实验从分子水平研究黄芩苷对SCs的抗热作用,为在实践中增强机体抗热休克能力提供了理论依据。 相似文献
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建立了绵羊(Ovis aries)粒细胞-巨噬细胞集落刺激因子基因(GM-CSF)的EvaGreen Real-time PCR方法,具有较高的灵敏性(检测精度在10个拷贝数以内)和特异性(溶解曲线仅出现一个产物峰).绵羊GM-CSF在脂多糖(LPS)诱导前不表达,在诱导4 h后逐渐增加,在8 h达到最高(470 930拷贝数/ng总RNA),在诱导16 h之后表达水平逐渐降低.表明Real-timePCR是一种灵敏、可靠的检测绵羊GM-CSF表达的方法,GM-CSF参与早期的免疫应答反应. 相似文献
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本试验通过测定EPP和NEPP对IL-1β和IL-6mRNA表达的影响,确定蓝莓可萃取多酚(EPP)及不可萃取多酚(NEPP)是否具有抗炎作用。结果表明,蓝莓中EPP和NEPP均能抑制细胞中IL-1β、IL-6 mRNA的表达,EPP的抑制效果要优于NEPP。当培养时间为48 h时,EPP和NEPP的添加浓度为10~200μg·mL-1对IL-1β和IL-6 mRNA抑制作用明显。当EPP的添加浓度为100μg·mL-1时,在12~48 h培养时间内,对IL-1β和IL-6 mRNA抑制作用明显;而100μg·mL-1NEPP处理组中,在48h时对IL-1β和IL-6 mRNA抑制效果明显。这表明从蓝莓中的NEPP同EPP一样可通过抑制IL-1β、IL-6 mRNA的表达表现出明显的抗炎作用,对今后蓝莓在医药保健方面研究奠定基础,不可萃取多酚的研究为多酚研究提供了新的方向。 相似文献
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小鼠胚胎干细胞体外定向诱导分化成骨细胞 总被引：3，自引：0，他引：3
将小鼠5d龄ES-D3细胞源的类胚体(EBs)单细胞,按5×104/mL接种6孔细胞培养板,在DMEM基础培养基中使EBs单细胞贴壁培养。于第14!21天时,分别添加60%成骨细胞条件培养液(A组)、50μg/mL维生素C"50mmol/Lβ-磷酸甘油(B组)和50μg/mL维生素C"50mmol/Lβ-磷酸甘油"1μmol/L地塞米松(C组),并设不添加诱导剂对照组(D组)。第22天时用1%茜素红染色显示阳性细胞,计算成骨细胞诱导形成率,数据用方差分析和多重比较检验。结果表明,A组细胞增殖呈团状聚集,茜素红染色阳性细胞结节多分布于聚集的细胞群内及其边缘,成骨细胞诱导形成率为10.04%,与对照组比较,差异极显著(P<0.01);B组诱导分化的细胞分泌物形成网状结构,茜素红染色阳性细胞分布在这些网状结构中,成骨诱导形成率为7.43%,与对照组比较差异显著(P<0.05);C组茜素红染色阳性细胞分散而均匀,但未出现网状结构,成骨细胞诱导形成率提高至27.57%,与对照组比较差异极显著(P<0.01)。 相似文献
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肺泡Ⅱ型上皮细胞(alveolar epithelial typeⅡcells,AECⅡ)是由呼吸道吸入的结核病原菌最先侵染的靶细胞.本研究通过建立结核分枝杆菌(Mycobacterium tuberculosis,Mtb)强毒株(H37Rv)、弱毒株(Bacillus Calmette-Guérin,BCG)感染AECⅡ细胞模型,分析不同感染时间Toll样受体(toll-liking receptors,TLRs)信号通路活化和炎症细胞因子分泌的差异,探讨AECⅡ细胞在Mtb感染时的免疫应答和持续感染的分子机制.利用H37Rv和BCG分别感染AECⅡ细胞系A549,通过荧光定量PCR和Western-blot等技术在核酸和蛋白水平分析感染6、12和24h时TLRs信号通路信号分子和促炎细胞因子的表达变化.结果表明,mRNA表达水平检测发现,在H37Rv感染A549细胞中,TLR2、TLR4、MyD88和NFκB在6h时显著高于BCG感染组;在感染24h时,两组TLR2、TLR4表达均上调,且差异不显著,而H37Rv感染组NFκB呈上调表达;在蛋白水平分析发现,在H37Rv感染引起A549细胞中MyD88和磷酸化NFκB表达呈显著下调趋势,且高于BCG感染组;而促炎细胞因子IL-1a、IL-6、IL-12a、IL-8、TNF-α和CSF2 mRNA表达水平随着感染时间升高,且H37Rv感染组IL-1a、IL-6 1L-8、TNF-α、和CSF2的表达显著高于BCG感染组,IL-12a差异不显著.本研究发现,Mtb强毒株感染AECⅡ细胞对TLRs信号通路表现为抑制趋势,且引起细胞的炎症反应明显强于弱毒株,这为阐明AECⅡ细胞在不同毒力结核分枝杆菌感染中的免疫调控机制研究和临床肺结核的发病机制研究提供了参考依据. 相似文献
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巨噬细胞产生的一氧化氮(nitric oxide,NO)在抵御及杀灭病原微生物过程中起重要作用。为了解哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路在结核分枝杆菌(Mycobacterium tuberculosis,MTB)感染宿主巨噬细胞过程中对NO的调控作用,本研究在卡介苗(Bacillus Calmette-Guérin,BCG)感染体外培养的BALB/c小鼠(Mus musculus)巨噬细胞系RAW264.7过程中添加mTOR信号通路的特异性抑制剂雷帕霉素(rapamycin),通过Griess、实时荧光定量PCR、Western blot等方法检测NO及诱导性一氧化氮合成酶基因(inducible nitric oxide synthase,iNOS)mRNA及其蛋白的表达情况,同时以脂多糖(lipopolysaccharides,LPS)处理的RAW264.7细胞作为参照。结果表明,与未经处理的空白对照组相比,BCG、LPS刺激6、12和24 h可以极显著增加RAW264.7细胞中NO的产生(P0.01),iNOS mRNA及其蛋白水平表达极显著增加(P0.01)。与未添加rapamycin组相比,BCG感染6和12 h时,10 nmol/L rapamycin可以极显著抑制RAW264.7细胞中NO的产生及iNOS的表达(P0.01),但24 h时rapamycin对产生NO的抑制作用不显著(P0.05),但同样可以极显著抑制iNOS的表达(P0.01);LPS刺激6和24 h时,10 nmol/Lrapamycin可以极显著抑制RAW264.7细胞中NO的产生(P0.01);12 h时,显著抑制NO的产生(P0.05);LPS刺激时,6 h时rapamycin对iNOS的表达的抑制作用不显著(P0.05),12和24 h时极显著抑制iNOS的表达(P0.01)。结果显示,rapamycin在MTB感染宿主巨噬细胞过程中对NO的产生有重要的调控作用,为揭示mTOR信号通路在结核病发生及发展过程中的作用提供重要的理论依据。 相似文献
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为探讨不同浓度黄芩苷对热应激条件下猪近端肾小管细胞(pig kidney proximal tubular cells,LLC-PK1)细胞凋亡率及B细胞淋巴瘤/白血病-2基因(B-cellymphoma-2,Bcl-2)和Bcl-2相关X蛋白基因(Bcl-2 associated X protein,Bax)表达的影响,将培养的LLC-PK1细胞随机分为7个组,Ⅰ组为37℃空白对照组,Ⅱ组为42℃单纯热应激1 h组,Ⅲ、Ⅳ、Ⅴ、Ⅵ和Ⅶ组分别为用不同浓度黄芩苷(0.01、0.1、1、10和100μg/m L)处理组后42℃热应激1 h组,运用实时荧光定量PCR和Western blot分别检测Bcl-2和Bax基因及蛋白的表达,流式细胞仪(Annexin V-FITC/PI双染法)检测细胞凋亡率。结果表明,与Ⅰ组相比,Ⅱ组能显著诱导LLC-PK1细胞Bcl-2 m RNA的表达(P0.05),极显著诱导细胞Bax m RNA和蛋白的表达(P0.01),能极显著降低细胞Bcl-2和Bax m RNA和蛋白的比值(P0.01),极显著增加细胞凋亡率(P0.01),但对细胞Bcl-2蛋白的表达无显著影响(P0.05)。黄芩苷处理组与Ⅱ组相比,Ⅳ、Ⅴ和Ⅵ组LLC-PK1细胞Bcl-2 m RNA的表达量均升高,其中Ⅴ组差异极显著(P0.01),Ⅳ及Ⅵ组差异显著(P0.05),Ⅲ及Ⅶ组差异不显著(P0.05),而细胞Bcl-2蛋白的表达量与Ⅱ组相比均差异不显著(P0.05);同样与Ⅱ组相比,黄芩苷处理的各组细胞Bax m RNA及蛋白的表达量均降低,其中Ⅴ及Ⅵ组差异极显著(P0.01),其余各组差异显著(P0.05);除Ⅲ组外,其他各组细胞Bcl-2和Bax m RNA及蛋白的比值与Ⅱ组相比均显著升高(P0.05),其中Ⅴ组细胞Bcl-2和Bax蛋白的比值差异极显著(P0.01);细胞凋亡率仅有Ⅲ组与Ⅱ组相比差异不显著(P0.05),而Ⅴ及Ⅵ组细胞凋亡率极显著低于Ⅱ组(P0.01),其余的Ⅳ和Ⅶ组显著低于Ⅱ组(P0.05)。一定浓度范围内的黄芩苷(0.1~100μg/m L)可能通过下调热应激条件下LLC-PK1细胞Bax的表达,从而提高Bcl-2和Bax的比值,降低细胞的凋亡率,对细胞起到保护作用。本研究从分子水平研究黄芩苷缓解热应激对猪LLC-PK1细胞的损害作用,可为明确其解热机制提供理论基础,并为其在临床上的应用提供有价值的参考资料。 相似文献
11.
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
13.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
14.
Aleš Lebeda Ivana Doležalová Eva Křístková Barbora Mieslerová 《Genetic Resources and Crop Evolution》2001,48(2):153-164
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions. 相似文献
15.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
16.
Thomas Larsen Jesper Luxhøi Jakob Magid Lars Stoumann Jensen Paul Henning Krogh 《Biology and Fertility of Soils》2007,44(1):59-68
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization
and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition
with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the
decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots
with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass,
soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration,
N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially
(<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation
in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils,
indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but
the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation
for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community
performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea. 相似文献
17.
《中国生态农业学报》2014,(7)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
18.
《中国生态农业学报》2014,(6)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
19.
Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
20.
《Communications in Soil Science and Plant Analysis》2012,43(7):865-877
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils. 相似文献