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1.
摘要 目的:探讨荆花胃康胶丸联合标准四联疗法对幽门螺杆菌(Hp)相关十二指肠溃疡(DU)患者血清肽类胃肠激素、胃蛋白酶原和炎症介质的影响。方法:选择2019年3月~2021年11月期间我院收治的Hp相关DU患者103例。按随机数字表法,将其分为对照组(标准四联疗法治疗,51例)和联合组(荆花胃康胶丸联合标准四联疗法治疗,52例)。对比两组疗效、Hp清除率、血清肽类胃肠激素[胃泌素(GAS)、胃动素(MTL)、 生长抑素(SS)和降钙素基因相关肽(CGRP)]、胃蛋白酶原[胃蛋白酶原Ⅰ(PGⅠ)、胃蛋白酶原Ⅱ(PGⅡ)]和炎症介质[白介素-8(IL-8)、白介素-1β(IL-1β)、转化生长因子β1(TGF-β1)],统计两组用药安全性。结果:联合组的临床总有效率、Hp清除率高于对照组(P<0.05)。两组治疗后血清IL-8、IL-1β、TGF-β1、PGⅠ、PGⅡ、GAS、MTL水平均下降,且联合组的下降程度大于对照组(P<0.05)。两组治疗后SS、CGRP均升高,且联合组的升高程度大于对照组(P<0.05)。两组不良反应发生率组间对比未见显著差异(P>0.05)。结论:荆花胃康胶丸联合标准四联疗法可通过提高Hp清除率、改善Hp相关DU患者的血清肽类胃肠激素、胃蛋白酶原和炎症介质水平,来进一步提高临床疗效。  相似文献   

2.
[背景] 工业酵母菌株的蛋白质表达通常存在表达量低、分泌效率低的问题。[目的] 考察失活Yapsin蛋白酶Yps1p和Yps2p对β-葡萄糖苷酶在酿酒酵母An-α菌株中表达的影响。[方法] 利用CRISPR/Cas9基因组编辑技术,首先构建得到未折叠蛋白响应(Unfolded Protein Response,UPR)指示菌株An-α(leu2::UPRE-lacZ)即An-αL,然后分别失活其YPS1和YPS2基因,导入以YEplac195为载体的β-葡萄糖苷酶表达质粒(简称BG),进行生长和酶活分析评价。[结果] 菌株An-αL的YPS1和YPS2基因失活对其在酵母浸出粉胨葡萄糖(Yeast Extract Peptone Dextrose,YPD)培养基中的生长未造成明显的不利影响;导入质粒BG后将在酵母浸出粉胨纤维二糖(Yeast Extract Peptone Cellobiose,YPC)培养基中生长的最大OD600分别提高了21.9%和7.4%;最大总酶活值为0.087 5和0.068 6 U/(mL·OD600),是对照菌株相应值的2.268倍和1.778倍;分泌比例提高了19.4%和22.2%;β-葡萄糖苷酶表达水平与β-半乳糖苷酶酶活水平所代表的UPR信号响应值之间呈现良好的相关性。[结论] YPS1和YPS2基因失活有助于改进酿酒酵母An-α菌株中β-葡萄糖苷酶的分泌表达。  相似文献   

3.
[背景] 小麦/玉米轮作是中国粮食作物主要种植模式之一,目前对小麦/玉米轮作田根际土壤微生物差异变化缺乏全面的了解。[目的] 明确小麦/玉米根际土壤微生物差异变化并了解其潜在功能。[方法] 以小麦/玉米根际土壤为材料,运用细菌16S rRNA基因和真菌rDNA ITS基因测序,分析小麦/玉米根际土壤微生物多样性。[结果] 玉米季微生物丰富度高于小麦季,而多样性无明显差异。放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)和绿弯菌门(Chloroflexi)为小麦季和玉米季根际土壤的优势细菌门,优势真菌门为子囊菌门(Ascomycota)。小麦季和玉米季共有细菌和真菌分别是631个和261个,小麦季特有细菌和真菌分别是38个和58个,玉米季特有细菌和真菌分别是25个和39个。LEfSe分析(LDA阈值为2)细菌和真菌表明,放线菌纲(Actinobacteria)和微囊菌目(Microascales)在小麦季富集,鞘脂单胞菌目(Sphingomonadales)和银耳纲(Tremellomycetes)在玉米季富集。小麦季、玉米季微生物代谢功能不同,与小麦季相比,玉米季养分循环的代谢通路丰富度较高,而参与氧化应激的代谢通路丰富度较低。[结论] 该研究结果对指导小麦/玉米轮作田管理具有理论和实践意义。  相似文献   

4.
[背景] 钙/钙调素依赖型蛋白激酶(Calcium/Calmodulin-Dependent Protein Kinase,CaMK)是真核生物细胞钙信号途径中钙调素下游的一类重要靶蛋白,对病原物生长、胁迫响应及致病性等具有重要的调控作用。[目的] 对梨果黑斑病菌互隔交链孢(Alternaria alternataAaCaMK基因进行克隆、生物信息学分析,并对其在侵染结构分化过程中的基因表达情况进行分析,为进一步研究梨果黑斑病菌钙离子信号途径中AaCaMKA.alternata侵染结构分化调控的分子机制提供一定的理论依据。[方法] 采用同源克隆法从A. alternata JT-03中克隆得到3个AaCaMK基因;通过TMHMM、ProtScale、SOPMA等软件对AaCaMK基因进行生物信息学分析;利用实时荧光定量PCR (RT-qPCR)技术分析AaCaMK在梨果黑斑病菌侵染结构分化过程中的表达情况。[结果] 克隆得到片段分别为1 212、1 200、2 349 bp的AaCaMK1AaCaMK2AaCaMK3基因;生物信息学分析表明,AaCaMK1、AaCaMK2和AaCaMK3均含有典型的蛋白激酶超家族催化结构域(PKC_Like Superfamily),并且AaCaMK1和AaCaMK2共同含有CaMK类丝/苏氨酸蛋白激酶催化结构域(STKc_CaMK),AaCaMK3含有LKB1/CaMKK类丝/苏氨酸蛋白激酶催化结构域(STKc_LKB1_CaMKK);同源性分析表明,AaCaMK1、AaCaMK2和AaCaMK3分别与玉米大斑病菌CAK1、CAK2和CAK3的相似性高达94.32%、97.49%和86.57%;RT-qPCR分析表明,AaCaMK1AaCaMK2AaCaMK3在疏水及果蜡诱导A. alternata侵染结构分化过程中均显著上调表达(P<0.05),而且果蜡诱导作用更显著。其中AaCaMK1AaCaMK2在附着胞形成时期(6 h)表达量为对照的1.51倍和3.05倍,而AaCaMK3在侵染菌丝形成阶段(8 h)表达量最高,为对照的2.86倍,并且在果蜡诱导下,这3个基因在芽管伸长阶段(4 h)的上调表达量显著高于疏水界面。[结论] 钙信号中AaCaMK基因在疏水及果蜡诱导A.alternata侵染结构分化过程中发挥重要的调控作用。  相似文献   

5.
[背景] 过氧化氢酶(catalase,CAT)参与真菌的生长发育,逆境胁迫时保护真菌免受氧化损伤。[目的] 实现草菇过氧化氢酶基因(VvCAT1)的异源表达,分析VvCAT1耐温度胁迫的功能。[方法] 克隆VvCAT1,构建过表达载体pBAR GPE1/VvCAT1,转化到大肠杆菌(Escherichia coli)菌株Stbl3中,异源表达草菇过氧化氢酶。测定温度胁迫后重组菌(pBAR GPE1/VvCAT1/Stbl3)与对照菌(pBAR GPE1/Stbl3)的过氧化氢酶活性和生长情况,验证VvCAT1的功能。[结果] 重组菌的CAT酶活性显著提高,生长情况显著优于对照菌。[结论] VvCAT1的导入及表达显著提高了大肠杆菌Stbl3的耐温度胁迫功能。  相似文献   

6.
[背景] 在结直肠肿瘤等多种肿瘤中普遍存在的具核梭杆菌(Fusobacterium nucleatum)与结直肠肿瘤发生、预后不良、复发及化疗耐药等密切相关。其引发炎症、对肿瘤微环境中巨噬细胞等免疫细胞作用与机制尚待阐明。[目的] 对比分析F.nucleatum脂多糖(Lipopolysaccharide,LPS)与嗜黏蛋白阿克曼氏菌(Akkermansia muciniphila)、大肠杆菌(Escherichia coli)的LPS诱导单核细胞极化、炎性细胞因子表达等活性差异,探讨F.nucleatum在诱发慢性炎症、致癌等过程中的作用与机制。[方法] 分别用A.muciniphilaE.coliF.nucleatum LPS或联合干扰素γ(Interferon-γ,IFN-γ)处理后,观察THP-1、THP-1 M0细胞的细胞形态变化,然后检测M0(CD11B)、M1(CD40CD86)和M2(CD163CD206)巨噬细胞标志基因、TLR3TLR4IL-6IL-10等基因转录水平,以及IL-6、IL-10、C反应蛋白(C Reactive Protein,CRP)翻译水平的表达变化。[结果] 聚丙烯酰胺凝胶电泳(Polyacrylamide Gel Electrophoresis,PAGE)分析显示,A.muciniphilaE.coliF.nucleatum这3种细菌的LPS条带位置、数量存在明显差异。F.nucleatum LPS在具有较强诱导THP-1细胞贴壁的同时,对经佛波肉豆蔻醋酸(Phorbol Myristate Acetate,PMA)处理贴壁的THP-1细胞,无论是单独或是联合IFN-γ处理,诱导形成伪足数、伪足长度及形成梭形细胞比例(M1型巨噬细胞)等均低于A.muciniphilaE.coli LPS。进一步转录水平检测巨噬细胞标志基因表达发现,M1标志基因中,CD40分别上调5 011.0%(P<0.001)、6 048.9%(P<0.001)和1 011.6%(P=0.009 4),CD86分别上调637.3%(P<0.001)、657.9%(P<0.001)和194.1%(P>0.05);M2标志基因中,CD163分别下调39.5%(P=0.001 1)、53.7%(P<0.001)和5.9%(P>0.05),CD206下调18.6%(P>0.05)、88.4%(P=0.005 5)和24.8%(P>0.05)。TLR、白介素家族基因转录水平分析发现,TLR3分别下调32.3%(P=0.044 7)、311.5%(P=0.001 9)、9.6%(P>0.05);IL-6分别上调17 763.2%(P<0.001)、35 458.2%(P<0.001)、1 123.6%(P>0.05);IL-10分别上调729.3%(P<0.001)、1 223.3%(P<0.001)、124.4%(P>0.05)。翻译水平上,A.muciniphilaE.coliF.nucleatum LPS单独或联合IFN-γ处理时,THP-1细胞产生IL-6分别为0.16、6.17、0 pg/mL与410.03、1 334.40、46.20 pg/mL。[结论] F.nucleatum LPS不仅具有较强招募单核细胞并诱导其向M2极化的作用,同时,具有诱导巨噬细胞分泌低浓度IL-6的特性,说明其在引发慢性炎症及肿瘤免疫应答、逃逸等过程中发挥重要作用。综合上述信息,对致癌、免疫激活及肿瘤治疗相关细菌LPS的结构、活性、分子机制等研究将有助于明确革兰氏阴性细菌在慢性炎症、肿瘤发生、免疫调控等中的作用,以期为相关疾病预防与治疗提供新的策略与靶点。  相似文献   

7.
四川地区猪源艰难梭菌分子分型调查   总被引:1,自引:0,他引:1  
[背景] 艰难梭菌是一种重要的人畜共患肠道病原菌,可引起人和多种动物抗生素相关性腹泻或假膜性肠炎。四川作为我国主要的生猪产区,还未有猪源艰难梭菌流行病学调查的相关报道,对猪源艰难梭菌的防控及保障猪肉安全带来挑战。[目的] 调查四川地区猪源艰难梭菌的感染、流行情况,并对分离出的艰难梭菌进行分子分型研究。[方法] 收集来自四川生猪主要产区6个养殖场中猪的粪便标本(n=110),采用厌氧培养技术在艰难梭菌鉴别培养基上进行分离培养;采用PCR方法扩增艰难梭菌4个毒素基因(tcdAtcdBcdtAcdtB)和7个管家基因(adkatpAdxrglyArecAsodAtpi),对分离株进行毒素基因分型和多位点序列分型。[结果] 从110份样品中,经革兰氏染色镜检及PCR鉴定,共分离出20株艰难梭菌,分离率高达18.18%;毒素基因分型结果显示共获得3种毒素基因型,包括tcdA+tcdB+cdtA/cdtB+n=3)、tcdA+tcdB+cdtA/cdtBn=6)、tcdAtcdBcdtA/cdtBn=11);多位点序列分型结果显示获得5个ST型,包括ST11(n=3)、ST3(n=1)、ST35(n=2)、ST36(n=4)、ST109(n=10);进化树结果显示,所有分离株聚集为2个大群,分别为3个分支和17个分支。[结论] 四川主要生猪产区猪群存在艰难梭菌感染,分离株的分子分型呈多样性,主要流行型为ST11、ST3、ST35、ST36、ST109型,并且存在ST11型高毒力菌株流行的风险。  相似文献   

8.
[背景] 马链球菌兽疫亚种(Streptococcus equi subsp. zooepidemicus,SeZ)是引起马腺疫的主要病原,还可引起猪链球菌病,加强该菌的地方株分子流行病学监测对有效防控相关疫病十分必要。[目的] 对新疆地区2个马场SeZ分离株进行鉴定和药敏特性分析,并分析3株新疆分离株的分子流行与菌株的遗传进化特征。[方法] 对分离纯化的3株病原菌(ZHZ113、ZHZ211和ZHZ523)进行染色观察、生化及药敏特性检测,对16S rRNA和SeM基因进行遗传进化分析,以链球菌7个管家基因arcCnrdEproSspitdktpiyqiL为目的基因对3株分离菌进行多位点序列分型(Multilocus Sequence Typing,MLST)研究。[结果] 3株SeZ的药敏结果显示这3株分离菌对不同抗生素的耐药程度不同,但均对头孢西丁、庆大霉素、链霉素、红霉素、左氧氟沙星、环丙沙星、土霉素等11种药物敏感。16S rRNA基因序列分析显示这3株分离菌均属于Ⅱ群(兽疫链球菌)。3株菌的MLST分型结果分别为ST39、ST419、ST421型,其中ST419和ST421型为SeZ目前尚未见报道的新ST型。SeM基因分析结果显示马源SeZ在不同国家、不同动物和不同时间段上的流行分布存在差异和动态变化的特点。[结论] 3株SeZ分离菌分别与美国犬源及马源菌株亲缘关系较近,反映部分SeZ株在新疆地区的基因型分布及分子流行特点。  相似文献   

9.
饶固  戴丹  张波  李玉 《微生物学通报》2021,48(10):3791-3798
[背景] 托光柄菇属(Volvopluteus)隶属于光柄菇科(Pluteaceae),目前世界上仅有4个种。[目的] 调查我国东北地区大型真菌资源。[方法] 采集大型真菌标本,对其形态进行详细的观察和描述,提取DNA,测定rDNA ITS序列,基于最大似然法和贝叶斯法构建系统发育树。[结果] 2019–2020年在吉林省延边朝鲜族自治州敦化市采集的标本中,有6份标本为密执安托光柄菇V.michiganensis,该种真菌此前未在我国发现。在系统发育分析中,采自我国的密执安托光柄菇V.michiganensis与该种的模式标本聚为一个分支。[结论] 密执安托光柄菇V.michiganensis为中国新记录种。  相似文献   

10.
唐正露  韩敏敏  曹堃  李亮  李郁 《微生物学通报》2021,48(11):4209-4220
[背景] 相较于灭活疫苗和弱毒疫苗,沙门氏菌(Salmonella)基因工程减毒活疫苗具有的优越性逐渐显现,研究也不断深入。[目的] 探究肠炎沙门氏菌G9菌株的4株基因缺失株G9(ΔhilA)、G9(ΔhilD)、G9(ΔssrABhilA)和G9(ΔssrABhilAhilD)的免疫效果及生物安全性。[方法] 以肠炎沙门氏菌基因缺失菌株G9(ΔhilA)、G9(ΔhilD)、G9(ΔssrABhilA)、G9(ΔssrABhilAhilD)及其亲本菌株G9的最佳免疫剂量接种小鼠后,利用间接ELISA法、流式细胞术、MTT法、小鼠攻毒试验及倾注平板法等对各缺失株的免疫效果和安全性进行评价。[结果] G9(ΔhilD)诱导血清IgG抗体效价最高,G9(ΔhilD)和G9(ΔssrABhilAhilD)产生肠黏膜IgA抗体效价最高,4株缺失菌诱导IL-4、IL-10、IFN-γ、TNF-β、MCP-1细胞因子的能力与亲本株G9差异不显著(P>0.05),产生的CD4+/CD3+、CD8+/CD3+ T细胞比率呈上升趋势,而且G9(ΔssrABhilA)和G9(ΔssrABhilAhilD)最高;G9(ΔssrABhilAhilD)诱发的脾淋巴细胞增殖指数最高;免疫小鼠后4株缺失株对G9攻毒提供的保护率为80%-100%,而且小鼠肝脏、脾脏及小肠绒毛无明显病理变化,对鼠伤寒沙门氏菌攻毒提供的保护率为50%-80%;接种后12 d,小鼠肝脏、脾脏及小肠中定殖的菌株能基本清除,而且在体外能连续稳定传代30代。[结论] G9(ΔhilA)、G9(ΔhilD)、G9(ΔssrABhilA)和G9(ΔssrABhilAhilD)对小鼠的免疫效果和生物安全性均良好,有成为肠炎沙门氏菌基因工程减毒活疫苗的可能。  相似文献   

11.
降水对鄂尔多斯高原克隆植物分布的影响   总被引:1,自引:0,他引:1  
鄂尔多斯高原地处半干旱区到干旱区的过渡带。通过沿鄂尔多斯高原从东到西的天然降水梯度的样带调查,分析了克隆植物的分布特征与降水的关系。结果表明:克隆植物的物种数量、占物种总数的比例和重要值以及根状茎型克隆植物的物种数量均与降水量呈显著正相关。5种优势植物克氏针茅、本氏针茅、黑沙蒿、赖草和短花针茅均为克隆植物,它们的分布也受降水影响。克氏针茅的密度、本氏针茅的盖度和密度、黑沙蒿的高度、盖度和密度以及赖草的高度均与降水量呈显著正相关。然而,赖草的盖度以及短花针茅的高度、盖度和密度均与降水量成负相关。因此,克隆植物在鄂尔多斯高原植被中具有重要作用,而且其作用随着降水量的增加而加强。  相似文献   

12.
In order to test the feasibility of using native halophytes to reclaim brinecontaminated soil, seedlings of five inland halophytes, Atriplexprostrata, Hordeum jubatum, Salicornia europaea, Spergularia marina, and Suaeda calceoliformis, were planted at threedensities on a site near Athens, Ohio which had been contaminated by oilwell brine water. Ten replicates of each density treatment weretransplanted on two distinct areas of high and low salinity in May of 1993. Seedling survivorship, soil moisture, and soil salinity were monitored weeklythroughout the growing season. Biomass production and ion uptake weredetermined for each plant surviving until harvest. Soil analyses wereperformed prior to planting and after harvest to determine overall changesin soil chemistry and to determine the amount of Na+ reductionfrom the soil due to leaching by precipitation during the course of theexperiment. Survival was determined to be density independent for all ofthe species with the exception of S. marina where survival wasfacilitated at high density. Increased salinity negatively affected the survivaland yield of A. prostrata. The remaining species had greater survivalunder high salinity conditions, and density appeared to be the key factorinfluencing yield. Sodium and chloride ions were accumulated in planttissues in much greater amounts than K+, Ca+2or Mg+2. Salicornia europaea plants grown in high densityon the high salinity site accumulated the highest amount of Na+ andH. jubatum grown in low density on the high salinity site accumulatedthe lowest amount of Na+. Soil salinities measured directly from theroot zone were significantly reduced (p<0.05) at the end of thegrowing season when compared to their controls. Atriplex prostrata(high density/low salinity) plots produced the greatest reduction in soilsalinity (15.8%) and S. marina (high density/high salinity) plots hadthe least reduction (1.2%).  相似文献   

13.
Pleurotus florida produced high amounts of laccase (4.60 U/ml) in malt extract broth after 12 days' growth under stationary conditions. The production of laccase was semi-constitutive. Hyperlaccase mutants ofP. florida were obtained through mutagenesis of mycelial protoplasts usingN-methyl-N-nitro-N-nitrosoguanidine (50 g/ml) for 2 min. Three hyperlaccase mutants were selected showing growth and enzyme production responses similar to the parent.  相似文献   

14.
A study of the type specimen ofUstilago jehudana resulted in the correction of the diagnosis. The sori are localized in the host gynoecium but not in the anthers. Morphological characters of the sori and ustospores of the later describedU. moenchiae-manticae are identical with these ofU. jehudana. Ustilago moenchiae-manticae is reduced here to a synonym ofU. jehudana. The smut is reported as new to Bulgaria on a new host, viz.,Moenchia erecta. A new combination,Bauhinus jehudanus, is proposed.  相似文献   

15.
Ants were the most apparent invertebrate scavengers observed foraging on entomopathogenic nematode-killed insects (i.e., insect cadavers containing entomopathogenic nematodes and their symbiotic bacteria) in the present study. Workers of the Argentine ant,Linepithema humile(Mayr), scavenged nematode-killed insects on the surface and those buried 2 cm below the soil surface. Ant workers scavenged significantly more steinernematid-killed (60–85%) than heterorhabditid-killed (10–20%) insects. More 4-day-postinfected cadavers (hosts died within 48 h after exposure to nematodes) were scavenged than 10-day-postinfected cadavers. Ten-day-postinfected hosts contained live infective juvenile nematodes therefore ants may serve as phoretic agents. Other ant species, includingVeromessor andrei(Mayr),Pheidole vistanaForel,Formica pacificaFrancoeur, andMonomoriom ergatogynaWheeler, also scavenged nematode-killed insects. These ant species removed or destroyed about 45% of the steinernematid-killed insects. These results suggest that survival of steinernematid nematodes may be more significantly impacted by invertebrate scavengers, especially ants, than that of heterorhabditid nematodes, and placement of steinernematid-killed insects in the field for biological control may be an ineffective release strategy. Because entomopathogenic nematodes kill insects with the help of symbiotic bacteria, we tested the role of these bacterial species in deterring invertebrate scavengers by injecting bacteria (without nematodes) into insects and placing the cadavers in the field. None of the insects killed by the symbiotic bacterium,Photorhabdus luminescens(Thomas and Poinar) fromHeterorhabditis bacteriophoraPoinar, were scavanged, whereas 70% of the insects killed by the symbiotic bacterium,Xenorhabdus nematophilus(Poinar and Thomas) fromSteinernema carpocapsae(Weiser), and 90% of the insects killed byBacillus thuringiensisBerliner were scavenged by the Argentine ant. We conclude thatP. luminescensis responsible for preventing ants from foraging on heterorhabditid-killed hosts.  相似文献   

16.
Two synthetic approaches leading toN-4-carboxymethyl-2-nitrobenzyloxycarbonyl derivatives of model compounds and of glycosylsphingosines are described. The carboxymethyl group can be converted into a hydrazido derivative and the resulting products react with an active ester polymer yielding light-sensitive polymeric products that may subsequently serve as acceptors in glycosyltransferase reactions.Author for correspondence. Address until September 1990; Graduate Department of Biochemistry, Brandeis University, 415 South Street, Waltham, MA 02254, USA  相似文献   

17.
Clémençon  Heinz  Hongo  Tsuguo 《Mycoscience》1994,35(1):21-27
Three species of Agaricales from Japan are treated here. 1) From the examination of the types and additional specimens,Lyophyllum nigrescens is conspecific withHydropus nigrita from Cuba. 2)Hydropus kansaiensis sp. nov. from Otsu appears close toTrogia mellea from Malaysia. 3)Alnicola lactariolens sp. nov. from Otsu is a distinctive species in this genus because of the purple color of its spore print.This work has been supported by a grant to one of us (H. C.) by the Japanese Society for the Promotion of Science in 1988/89.  相似文献   

18.
Distribution of VA mycorrhiza on halophytes on inland salt playas   总被引:5,自引:0,他引:5  
The value of mycorrhizal association for higher plants has been well established. However, the impact of high salinity on the mycorrhizal relationship has not been investigated to any great extent. Inland salt playas represent an opportunity to test the impact of salinity because it is possible to obtain a gradient by following a transect from the centre of the salt playa to the higher outer zones. In a salt playa near Goshen, Utah, the sodium concentration ranged from 27,150 ppm in the centre to 25 ppm in the outer zone. In the playas with sodium concentrations of 20,000 ppm, no mycorrhiza were detected on the halophytes and no spores of mycorrhizal fungi were found in the soil. One percent of the roots of salt grass in soils containing 8,450 ppm of sodium were mycorrhizal. In soils containing 622 ppm of 45 percent of the roots of a salt-tolerant grass (hybrid ofAgropyron repens × Agropyron spicatum) were mycorrhizal. Halophytes such asSalicornia pacifica var.utahensis which are among the most salt tolerant halophytes of the inland salt playas rarely had mycorrhizal roots. The mycorrhizal associations appear to be very limited in inland salt playas with sodium content.  相似文献   

19.
Summary Dry deposition of gases and airborne particles is reviewed in particular relation to their interaction with vegetation. Once deposited, pollutants overcome the system of resistances (air, cuticular, stomatal and mesophyll) and penetrate key physiological points that affect the plant's biochemistry. Strong relationships have been found between gases in the environment and the chlorophyll content of leaves, production and partitioning of dry matter, relative growth rate and net assimilation rate. Physical modes of dry deposition involving anthropogenic pollutants present in the surface layer and micrometeorological conditions allowing their diffusion in the canopy are also discussed, with emphasis on measurement techniques.  相似文献   

20.
Floral ontogeny ofCleome spinosa, Cleome violacea andPolanisia dodecandra subsp.trachysperma was studied in the context of the question whether the fascicled androecium ofReseda andCapparis (with fused fascicles) or the 2 + 4-pattern of theBrassicaceae is primitive in theCapparales. InPolanisia dodecandra, the 9–18 stamens show unidirectional initiation from the adaxial side toward the abaxial side of the flower. InCleome violacea, the six stamens also are formed in an unidirectional order, but development starts abaxially and a zigzag-like pattern is superimposed. InCleome spinosa, two stamen primordia in transversal (lateral) position are followed by four stamens which arise on a somewhat higher level in two pairs in front of the median sepals. It is assumed that the evolutionary steps in the androecial development proceed fromReseda viaCapparis andPolanisia/Cleome toBrassicaceae. This interpretation is supported byrbcL-studies (Chase & al. 1993,Rodman & al. 1993).Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday  相似文献   

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