NH4+对不同基因型棉花幼苗K+吸收和利用的影响

溶液培养条件下研究了NH4+对棉花不同基因型幼苗干物质积累以及K+吸收和利用的影响。结果表明,NH4+在不同供钾条件下均显著降低了棉花幼苗的干重、钾吸收量和钾利用指数,低钾条件下（K+ 0.03 mmol/L）尤其如此。中等供钾（K+ 0.5 mmol/L）在一定程度上缓解了NH4+对棉花幼苗干物质积累以及K+吸收和利用的抑制; 充分供钾 （K+ 2.5 mmol/L）却未能在中等供钾的基础上进一步减轻NH4+的毒害作用。鲁棉研22苗期的干物质积累在不同供钾条件下受NH4+影响的程度均较153018品系大,这主要与其体内钾利用能力受NH4+影响较153018大有关。     

不同供铵水平对番茄根系生长的影响

植物根系对各种养分供应高度敏感。本文以番茄为研究材料,采用整株和根部琼脂培养方法,研究不同浓度NH4+对根系生长的影响。结果表明：当整体供NH4+ 浓度大于0.5 mmol/L,主根长、侧根数和株高均随着NH4+ 的增加而变小,10 mmol/L NH4+ 几乎完全抑制了侧根形成。整体供NH4+ 对番茄生长的抑制效应大于相等浓度的NH4+ 仅供应于根部。而低浓度的NH4+ （10 ~ 100 mmol/L）供应于根部,在基本不影响主根长度的情况下,能显著增加侧根数量。依据所使用的NH4+ 浓度及不同的供NH4+方式,NH4+对番茄生长特别是侧根形成具有显著的抑制作用或促进效应。     

K+高亲和转运系统吸收动力学特征及其受NH4+影响的研究

为探讨钾的高亲和转运系统是否受到铵离子的影响,采用溶液培养方法研究了水稻、大豆两种作物苗期(16d)的K+高亲和转运系统吸收动力学特征及其受吸收液中NH4+的影响。结果表明,NH4+对K+吸收的Vmax的影响在作物种类间有较大的差异,水稻受影响显著小于大豆。NH4+对供试作物K+吸收的Km值影响均很小,说明NH4+对K+吸收速率的影响主要在于影响了细胞膜上K+载体的数量而非影响了载体吸收位点与K+之间的亲和性。     

Effects of arbuscular mycorrhizal fungi on the growth and zinc uptake of trifoliate orange (Poncirus trifoliata) seedlings grown in low-zinc soil

The effects of the arbuscular mycorrhizal (AM) fungi, Glomus intraradices and G. versiforme, on growth and zinc (Zn) uptake were investigated in trifoliate orange (Poncirus trifoliata) seedlings exposed to low-Zn soil. Low-Zn decreased growth, levels of leaf chlorophyll, soluble protein and sugar, and soil enzymatic activities, and pH in 0–2 cm rhizosphere soil. Low-Zn soil also decreased mineral nutrients (including Zn) concentrations in the shoots and roots. Glomus intraradices especially, significantly enhanced plant biomass, leaf soluble protein and sugar concentrations, root viability, acid phosphatase, catalase, invertase and urease activities, and easily extractable glomalin content in 0–2 cm and 2–4 cm rhizosphere soil. It also increased concentrations of Zn, phosphorus, potassium and magnesium in the shoots and roots, while decreased the soil pH. Arbuscular mycorrhizal fungi, especially G. intraradices, has the potential to improve growth and Zn uptake of triofoliate orange seedlings grown in low-Zn soil.     

几种铵盐对土壤吸附Cd2+和Zn2+的影响

采用平衡吸附法,研究了不同铵盐对潮褐土、红壤吸附Cd2+、Zn2+的影响。结果表明,土壤对Cd2+、Zn2+的吸附量随平衡溶液中Cd2+、Zn2+浓度的增加而增加;潮褐土和红壤对Cd2+、Zn2+的最大吸附量为:Zn2+ Cd2+,且潮褐土红壤;随NH4HCO3浓度的增加,两种土壤对Cd2+、Zn2+的吸附率显著提高,NH4Cl、NH4NO3和(NH4)2SO4抑制红壤对Cd2+、Zn2+的吸附及潮褐土对Cd2+的吸附,对潮褐土Zn2+的吸附率影响不显著;铵盐浓度相同时,红壤对Cd2+吸附率为:NH4HCO3NH4ClNH4NO3≈ (NH4)2SO4,红壤对Zn2+吸附率为:NH4HCO3NH4Cl NH4NO3(NH4)2SO4。     

水培条件下CO2与NH+4/NO-3配比对番茄幼苗生育的影响

升高CO2浓度能够促进作物的光合作用,提高作物的生物量和产量,但关于CO2与NH+4/NO-3比及其交互作用对作物影响的研究较少,为探索番茄幼苗生长发育对CO2浓度升高的响应是否对NH+4/NO-3配比有较强的依赖关系,本试验在营养液栽培条件下,以番茄(Lycopersicun esculentum Mill)为试材,研究正常大气CO2浓度(360μL/L)和倍增CO2浓度(720μL/L)与不同NH+4/NO-3配比的交互作用对番茄幼苗生长的影响.结果表明:CO2浓度升高提高了低NH+4/NO-3比例处理中番茄叶片的光合速率和水分利用率,提高幅度随NH+4/NO-3比例的降低而增强,光合速率增强最大达55%.在同一CO2浓度处理下净光合速率与水分利用率均随NH+4/NO-3比例的增加而显著降低.这说明CO2浓度升高对番茄幼苗生长发育的促进作用随NH+4/NO-3比例的降低而提高,但并没有减弱全NH+4-N处理中番茄幼苗的受毒害作用.综上所述,CO2浓度升高能提高植物生产的节水能力和水分生产力;水培条件下,NO-3-N是最适合番茄幼苗生长发育的氮源,其它NH+4/NO-3比例对番茄幼苗的生长发育有一定的抑制作用,仅以NH+4-N作氮源则番茄幼苗很难生长.     

The effects of several buffers on growth and phosphorus nutrition of selected ectomycorrhizal fungi

Six buffers were tested in agar medium with Laccaria laccata (Scop. ex Fr.) Cke., Paxillus involutus (Batsch. ex Fr.) and Pisolithus tinctorius (Pers.) Coker & Couch. Both acetate and ADA (N-[2-acetamido] iminodiacetic acid) were inhibitory to radial growth of all three species. ACES (N-[2-acetamido]-2-aminoethanesulfonic acid) had a variable effect on radial growth depending on fungal species. The effect of glycine was inconclusive due to the elevation of pH following autoclaving of the media containing this buffer. MES (2-[N-morpholino] ethanesulfonic acid) enhanced the growth of all three fungal species PIPES (piperazine-N,N′-bis[2-ethanesulfonic acid]) also stimulated radial growth, but only two of the three species were affected.Laccaria laccata and P. involutus were also grown in liquid media containing either an inorganic (iP) or organic (oP) P source and MES, PIPES or phthalate or no buffer at all. As in the case of solid media, effects not only varied with type of buffer, but fungal species reacted differently to a given buffer. For example. MES enhanced growth of L. laccata on both media, but reduced oP hydrolysis by this species. P. involutus growth was enhanced by MES only on iP medium. PIPES enhanced fungal growth and did not interfere with the hydrolysis of oP nor the uptake of P by the fungi.     

Comparison of the Effects of Wet N Deposition (NH4Cl) and Dry N Deposition (NH3) on UK Moorland Species

Increases in N deposition (wet and dry) have been associated with a decline in semi-natural plant communities, adapted for growth on nutrient poor soils in the UK and Europe. The impacts of N deposition applied as either wet NH₄ ⁺ or gaseous NH₃ on vegetation (7 species) from acid moorland in SE Scotland were compared in a dose-response study. Wet N deposition at 0, 8, 16, 32, 64, 128 kg N ha^?1 y^?1 was applied as NH₄Cl, and dry deposition as gaseous NH₃ (2, 6, 20, 50, 90 µg NH₃ m^?3) under controlled conditions in open-top chambers. A strong linear dose-response relationship (p<0.05) was found between foliar N content in all seven plant species and applied NH₄?N. However, in the NH₃ treatment, only C. vulgaris and P. commune showed a significant response to increasing N additions. NH₃ was found to increase the rate of water loss in Calluna in both autumn and winter by comparison with wet deposition. For Eriophorum vaginatum, the NH₃ and NH₄ ⁺ treatments showed significant N dose response relationships for biomass. A significant increase in above ground biomass, proportional to the added N, was found for Narthecium ossifragum when N was applied as NH₃ compared to NH₄ ⁺.     

铵态氮/硝态氮对水稻铝吸收的影响及其机制研究

选用两个水稻品种武运粳7号（耐铝品种）和扬稻6号（铝敏感品种）作为实验材料,利用水培试验,通过长期和短期处理相结合的方式研究了NH4+-N和NO3--N对水稻Al吸收的影响及其作用机制。结果表明,与NH4+-N相比,NO3--N促进了水稻对Al的吸收。而且随着NO3--N浓度的提高,水稻根中Al含量显著增加,随着NH4+-N浓度的提高,水稻根中Al含量显著降低。这些结果表明NH4+-N和NO3--N对水稻Al吸收的影响具有浓度效应。当向Al溶液添加pH缓冲剂后,NH4+-N和NO3--N对根尖Al累积的影响变小,表明NH4+-N和NO3--N处理下溶液pH的变化可能是NH4+-N和NO3--N对水稻Al吸收影响不同的一个原因。     

铵对不同作物根系钾高亲和转运系统的影响

为探讨植物苗期根系高亲和转运系统的K+吸收动力学特征及其是否受吸NH4+的影响,采用溶液培养和添加K+通道抑制剂的方法,对低K+浓度下5种植物在有铵和无铵时的K+吸收动力学特征进行了研究。结果表明,植物根细胞K+高亲和系统的吸钾特征曲线符合Michaelich-Menten方程。不同植物K+高亲和系统的Km值之间差异较小,均在50%以内,说明不同植物的载体与K+间的亲和性差异较小;不同植物K+高亲和系统的Vmax值间差异很大,说明不同植物根细胞膜上的K4+载体数量间差异很大,这是导致不同植物在低钾条件下吸钾能力差异较大的主要原因。铵的存在可以明显降低供试植物在低钾条件下对K+的吸收速率。与无NH4+情况比较,NH4+的存在可使大豆K+吸收的Vmax减少80%;但NH4+对不同载体与K+之间亲和性(Km的影响较小,由NH4+所导致的Km的降低率均在10%以内。可见,对高亲和系统而言,NH4+对K+吸收的影响主要是由于铵竞争细胞膜上的钾载体所造成的。     

不同铵硝配比营养液对典型生菜硝酸盐吸收动力学的影响

利用100%NO3--N、10%NH4+-N+90%NO3--N、10%NH4+-N+100%NO3--N营养液来研究生菜吸收NO3-的动力学特征。结果表明,生菜吸收NO3-的速率随着营养液中NO3-浓度的增加而增加,增加的幅度随着营养液中NO3-浓度的增加而减少。NH4+-N的存在对生菜吸收NO3-有明显抑制作用。与100%NO3--N处理相比,生菜在10%NH4+-N+90%NO3--N1、0%NH4+-N+100%NO3--N处理中吸收NO3-的速率和Vmax有明显下降,Km有少量增加,但差异不显著。申选1号在有NO3--N的营养液中吸收NO3-的速率均大于耐热耐抽苔生菜,且随着营养液中NO3-浓度的增加,两者的差距逐渐加大。在NH4+-N的存在情况下,耐热耐抽苔生菜Vmax下降的程度大于申选1号,而Km增加的程度小于申选1号。     

溶磷真菌促进磷素吸收和作物生长的作用研究

在盆栽条件下,利用花生、玉米、油菜在3种不同磷水平的石灰性土壤上,采用土壤耗竭性连续种植的方法,研究了溶磷青霉菌P8对吸收土壤磷素和作物生长的影响。结果表明,3种土壤上接种青霉菌P8菌剂都能提高作物的吸磷量,其生物产量比不接种显著提高,且在有效磷低的土壤上其增产幅度大于有效磷高的土壤;接种青霉菌P8在一定程度上能缓解和改善低温对作物生长和磷素吸收的不良影响。无论在有效磷高还是低的土壤,青霉菌P8都具有活化土壤磷、提高土壤磷素的利用效率和促进作物苗期生长的作用。     

硝铵比例影响小白菜生长和叶绿素含量的原因探究

采用溶液培养试验研究了不同NO3-∶NH4+比例,分别为5.00∶0.00、3.75∶1.25、2.50∶2.50、1.25∶3.75和0.00∶5.00(mmol/L)对小白菜生长和叶绿素含量的影响及其原因。结果表明,1)与纯硝营养相比,NO3-∶NH4+为3.75∶1.25(mmol/L)时,小白菜具有最大的生物量、叶面积和叶片细胞分裂素含量;2)SPAD值、叶片可溶性蛋白质和活性铁含量均随着铵态氮比例的增加而增加;3)叶片细胞分裂素含量与叶面积、叶面积与生物量间的相关显著,相关系数(r)分别为0.97、0.95(P0.05);SPAD值与叶片可溶性蛋白质以及和活性铁含量之间的相关系数(r)分别为0.99和0.97(P0.05)。适当提高铵态氮比例可以增加小白菜叶面积可能是因提高了叶片细胞分裂素含量从而促进其扩展,进而影响生物量;提高铵态氮比例可以提高叶绿素含量,与提高了叶片蛋白质和活性铁的含量有关。     

沸石不同粒径组成对NH_4~+-N、H_2PO_4~--P和K~+吸附-解吸的影响

为了对沸石不同用途进行准确选材,实现其高效利用,研究了天然斜发沸石的6种粒径对NH_4~+-N、H_2PO_4~--P和K~+吸附、解吸的影响。结果表明:对沸石吸附和解吸3种离子,不同粒径间数值差异显著,表现规律也不同。NH_4~+-N的吸附量和解吸量分别相差4.31倍和4.93倍;K~+分别相差7.89倍和81.77倍。随粒径变小,沸石对NH_4~+-N和K~+的吸附与解吸量均呈先升高后降低的趋势,对H_2PO_4~--P的吸附量呈负值到较低正值的变化,解吸量为0。对3种离子的最大吸附量分别为8 354.62、74.33和2 722.25 mg/kg,最大解吸量分别为7 423.29、0和875.70 mg/kg。在NH_4~+-N和K~+的吸附方面,适宜选择粒径为40μm的天然沸石;而对H_2PO_4~--P,各粒径的天然沸石效果均不适宜,需要进行改性处理后应用。     

Leaching behaviour of a sandy soil amended with natural and NH4+ and K+ saturated clinoptilolite and chabazite

Using saturated or enriched zeolites as slow release fertilizers (SRFs) is considered as an environmental-friendly strategy to enhance use of macronutrients in sandy soils. In this paper, two natural zeolites, clinoptilolite (CLI) and chabazite (CHA) were used as mineral precursors to prepare NH₄⁺/K⁺ saturated clinoptilolite (NH₄⁺/K⁺-CLI) and chabazite (NH₄⁺/K⁺-CHA) as zeolitic nutrient sources (ZNSs). Comparison between the nutrient retention capabilities of these ZNSs was one of the main objectives of this study. The NH₄⁺/K⁺-CLI and NH₄⁺/K⁺-CHA were prepared by soaking the zeolites in NH₄Cl and KCl solutions, respectively. Leaching tests were performed on a sandy soil amended with chemical fertilizers (CFs), NH₄⁺/K⁺-CLI and NH₄⁺/K⁺-CHA to evaluate the leaching properties of them. The results indicated that approximately 84% and 88% of the NH₄⁺ and K⁺ of soils fertilized with CFs were lost during the experiment, respectively. While, the NH₄⁺ and K⁺ losses from soils amended with NH₄⁺/K⁺-CLI and NH₄⁺/K⁺-CHA were 29%, 23%, and 14%, 24%, respectively. Despite of drastic changes in leaching behavior of CFs, nutrient losses from ZNSs were more uniform during the experiments. No significant difference was found between the two studied zeolites on reduction of K⁺ loss. However, CHA was more effective in preventing NH₄⁺ loss during leaching.     

不同硝铵比氮素供应对广藿香生长及药效成分的影响

【目的】探讨不同硝铵比氮素营养对广藿香生长、产量、生理效应、挥发油及药效成分的影响,为提高广藿香的产量和药用品质提供氮肥施用依据。【方法】以海南藿香为研究材料进行了砂培盆栽试验。设5个不同NO₃–-N/NH₄+-N比处理为100∶0、75∶25、50∶50、25∶75、0∶100,每隔10天浇一次,每次250 mL/盆,每盆定植1株6 cm高的广藿香组培苗。采收期分为定植后60、120、180、240天,每个处理每次采取4盆,分析了广藿香生长指标、叶绿素、抗氧化活性及药效成分。【结果】硝铵比为75∶25的处理更能促进广藿香的株高、茎粗、分蘖数、叶面积指数、地上部鲜重、地上部干重、茎含油率、叶含油率、全株含油率和单株含油量增加,也有利于叶绿素a和叶绿素a + b含量提高。硝铵比为75∶25处理的广藿香植株N、P、K、Ca、Mg元素吸收最多,硝铵比为25∶75和0∶100处理的较低。硝铵比为50∶50的处理有利于叶绿素b含量和苯丙氨酸解氨酶 (PAL酶) 活性的提高,有助于广藿香茎叶的广藿香酮的提高。硝铵比为25∶75和50∶50的处理更有利于羟自由基、超氧阴离子自由基、DPPH自由基清除率的提高。硝铵比25∶75处理有利于广藿香茎叶广藿香醇和其他主要药效成分含量的提高。全硝态氮和全铵态氮 (硝铵比为100∶0和0∶100) 处理不利于或抑制广藿香茎叶油的药效成分形成和积累。【结论】供应硝铵比为75∶25的氮更能促进广藿香生长和光合效能的提高,硝铵比为50∶50、25∶75处理更能促进广藿香主要药效成分含量的提高。     

渗透胁迫对玉米幼苗根系活力和K+吸收动力学特征的影响

本试验以三个抗旱性不同的玉米品种作为试验材料,以26％聚乙二醇Polyethylene.glycol(PEG)(分子量4000)溶液对幼苗进行模拟渗透胁迫,研究了渗透胁迫对3个抗旱性不同的玉米品种幼苗根系活力及对K+吸收的动力学的影响。结果表明,玉米幼苗根系对K+的吸收速度符合Michaelis-Menten动力学方程;短期(24h内)的渗透胁迫可在一定程度上促进根系的生长,根系活力增强,NR活力升高,根系与离子的亲和力增加(Km下降),抗旱性强的品种促进程度大于抗旱性弱的品种;较长时间(超过48h)的渗透胁迫则抑制根系的生长,根系活力、NR活性等降低,根系与离子的亲和力下降(Km升高)。抗旱性强的品种受抑程度轻,Km值的升幅小,而抗旱性弱的品种受抑程度重,Km值的升幅大。玉米幼苗根系吸收K+的Km与根数、根重、根系活力、吸收面积、NR活力等极显著相关,可作为玉米抗旱性强弱的指标。     

Study of K+ uptake kinetics of flue-cured tobacco in K+-enriched and conventional tobacco genotypes

Screening of potassium efficient genotypes will be one of the best ways to solve the low potassium content of flue-cured tobacco. The study was conducted to determine whether the potassium efficient genotypes could be screening with high K⁺ uptake efficiency. The K⁺ uptake characteristics of a high K⁺ content line (GK8) and the conventional cultivated variety (K326) of flue-cured tobacco were compared at the seedling stage. K_m, C_min, and I_max values were higher in young seedlings (4?～?5 versus 6?～?7 leaf stage) and cultures with high initial K⁺ concentration (0.35 versus 0.25?mmol?L^?1). Culture solutions with a high K⁺ concentration (2.0 versus 0.6?mmol?L^?1) showed a high K_m, and C_min, but the I_max was lower as compared with the young seedlings and the solution with high initial K⁺ concentration. In conclusion, the GK8?line had a stronger ability for limited K⁺ uptake than K.     

砷胁迫条件下接种丛枝菌根真菌对番茄生长和磷吸收的影响

采用盆栽法研究了砷(As)污染条件下(As 0,50,100和200 mg·kg-14个水平)丛枝菌根真菌(AMF)接种对全生育期番茄植株生长及其磷(P)营养的影响。试验中各接种处理均成功侵染,侵染率在11.79%~34.36%之间。砷胁迫显著影响番茄植株的生物量,植株生长过程中各个时期地上部和根系干重均随As添加水平的升高而显著下降。本试验同时发现As 50 mg·kg-1是不接种番茄植株忍受砷毒害的上限,而接种丛枝菌根真菌后,番茄忍受砷毒害的上限上调到100 mg·kg-1;但200 mg·kg-1已达番茄忍受砷毒害的极限。基质中添加砷对番茄植株不同生长时期地上部和根部磷含量有显著影响。除开花期地上部与其不接种处理根部磷含量外,幼苗期和坐果期植株地上部磷含量与根部磷含量均随着砷添加量的增加而呈大致递增趋势。番茄植株生长的各个时期(幼苗期、开花期和坐果期)地上部和根部磷吸收量随砷添加水平的增加呈明显下降趋势。砷污染条件下,接种丛枝菌根在一定程度上促进了植株生长及其对磷的吸收,缓解了砷对植株生长的胁迫。     

Effects of arbuscular mycorrhizal fungi on zinc uptake, translocation and accumulation in winter wheat during whole plant growth stages

Although arbuscular mycorrhizal fungi (AMF) could play important roles in zinc (Zn) uptake in host plants, the effects of AMF on Zn uptake and transport in winter wheat during the whole growth stages remain unclear. A pot experiment was conducted to investigate the effects of Funneliformis mosseae (Fm) and Claroideoglomus etunicatum (Ce) on Zn absorption, transport, and accumulation in winter wheat growing in soils spiked with different Zn levels (0, 2.5, and 25 mg kg^-1). The results showed that there was a significant correlation between mycorrhizal colonization rate and Zn absorption efficiency in winter wheat roots during the post-anthesis period, but there was no significant correlation during the pre-anthesis period. Arbuscular mycorrhizal fungi significantly increased Zn concentrations (0.56-1.58 times) in wheat grains under 0 mg kg^-1 Zn level, but decreased Zn concentrations in wheat grains under 25 mg kg^-1 Zn level. Additionally, at the filling and maturity stages, AMF increased Zn absorption rate and the contribution of root Zn uptake to grain Zn by 3-14 and 0.36-0.64 times, respectively, under 0 mg kg^-1 Zn level and 0.21-1.02 and 0.27-0.37 times, respectively, under 2.5 mg kg^-1 Zn level. However, AMF decreased root Zn absorption rate (0.32-0.61 times) and increased the contribution of Zn remobilization in vegetative tissues to grain Zn (1.69-2.01 times) under 25 mg kg^-1 Zn level. This study would complement the mechanisms and effects of AMF on Zn absorption and transport in winter wheat and provide a potential method for the application of AMF to enrich wheat grain Zn.