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以带菌(E+)和不带菌(E-)的中华羊茅为试材,采用培养皿纸上发芽法,研究了不同NaCl浓度对中华羊茅幼苗苗长、根长、苗鲜重和根鲜重的影响,以期为内生真菌对宿主耐盐性的作用提供参考依据。结果表明:E+幼苗中,盐浓度为1.0~8.0mmol/L时显著促进苗长、根长和苗鲜重的增加(P0.05),而1.0~2.0mmol/L盐浓度对根鲜重有明显增效作用(P0.05);E-幼苗中,1.0~2.0mmol/L盐浓度显著增加根长(P0.05),2.0~8.0mmol/L盐浓度明显增加苗鲜重(P0.05),盐浓度8.0mmol/L显著抑制根的伸长和鲜重(P0.05)。与E-幼苗相比,对照条件下除内生真菌显著增加苗鲜重外(P0.05),其它所测生长指标均无明显差异性;在1.0~8.0mmol/L盐浓度下内生真菌显著增加根长和苗鲜重(P0.05),在1.0~4.0mmol/L盐浓度下内生真菌明显促进苗长(P0.05),在2.0mmol/L或8.0mmol/L盐浓度下内生真菌明显增加根鲜重(P0.05);苗长与根长或苗鲜重相关系数较高,且内生真菌能提高其相关系数。 相似文献
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以"魁冠宏丰"番茄为试材,采用珍珠岩/蛭石(V/V 2∶1)栽培方式,在总氮水平15 mmol·L-1下,设置铵态氮+硝态氮0 mmol·L-1+15 mmol·L-1(A0N15,对照)、5 mmol·L-1+10 mmol·L-1(A5N10)、7.5 mmol·L-1+7.5 mmol·L-1(A7.5N7.5)、10 mmol·L-1+5 mmol·L-1(A10N5)、15 mmol·L-1+0 mmol·L-1(A15N0)处理,研究了同一氮水平下,不同铵态氮和硝态氮配比对番茄幼苗生长和铵同化的影响,以期为提高番茄铵同化能力提供参考依据。结果表明:植株的总干质量在A5N10、A7.5N7.5处理较对照增加了27%、20%,A10N5处理与对照差异不显著,A15N0处理则降低了22%;分析发现根系和叶片中总游离氨基酸的含量随着铵态氮配比的增加而增加,增加了40%以上。参与氮代谢的谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)、谷氨酸脱氢酶(GDH)活性在根系中均显著高于对照;同时谷氨酰胺(Gln)、谷氨酸(Glu)含量随着铵态氮配比的增加不断增加,但A10N5、A15N0处理Glu含量显著下降,同时可溶性糖、淀粉、叶绿素含量下降。营养液中铵态氮浓度达到10 mmol·L-1及以上水平时,植株生长受到抑制,一方面是叶片叶绿素减少导致碳同化受阻,影响根系的氮同化,另一方面是Glu含量减少导致氮同化受抑制,从而植物生长受到抑制,生物量降低。 相似文献
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NH_4/ NO_3及温度对结球生菜硝酸盐含量的影响 总被引：2，自引：0，他引：2
叶菜类蔬菜均有累积硝酸盐的特性。吸收到植物体内的一部分硝酸盐会转化为亚硝酸盐,成为有害物质。为此,笔者进行了为期5年降低叶菜类蔬菜硝酸盐含量的试验。材料采用7个结球生菜品种,分别在不同季节利用营养液膜栽培法(NFT)种植。营养液中的氮素一硝态氮100%,或硝态氮80%、铵态氮20%,以10mmol/L为基准。结果,氮素全为NO3(硝态氮)时,结球生菜中硝酸盐的含量较高,若把氮素中NO3(硝态氮)的20%转换成NH4(铵态氮),硝酸盐的含量就较低。采收前 2～3周再把NH4(铵态氮)的比例增加到50%或80%,结果叶球鲜重没有减少,而叶的硝酸盐含量有所下降。 … 相似文献
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以荷兰彩椒品种‘Mandy’为试材,对温室无土栽培彩椒进行2.5、5.0、10.0(CK)、15.0、20.0μmol/L(以N2.5、N5.0、N10.0、N15.0、N20.0表示)5个不同氮素水平处理,研究其对彩椒生长、产量、干物质及全氮含量的影响。结果表明:单株全氮含量依次为N15.0(1.6148g)N20.0(1.5000g)N10.0(1.4500g)N5.0(1.4132g)N2.5(1.3670g)。株高在N2.5~N15.0氮素处理浓度范围内,随浓度增加呈递增趋势,而在N15.0~N20.0处理浓度范围内则呈递减趋势;单株叶片数依次为N10.0N15.0N5.0N20.0N2.5;单株叶面积依次为N15.0N20.0N10.0N5.0N2.5。各个器官中的氮素分配比例不受不同氮素水平处理的影响,而不同器官中全氮含量则不同。干物质积累方面,在结果期,根部和叶片随氮的增加而增加,果实以施氮量少的增加明显,茎的各处理间差异不明显;在成熟期,茎和叶片随氮的增加而下降,果实随氮的增加呈明显上升趋势,根的各处理间差异不显著。产量依次为N15.0N5.0N10.0N20.0N2.5。试验认为温室无土栽培彩椒最佳氮素施用浓度为15.0μmol/L。 相似文献
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刺梨实生苗对硝态氮、铵态氮的吸收与利用差异分析 总被引：2，自引：0，他引：2
《果树学报》2017,(6)
【目的】研究刺梨(Rosa roxburghii Tratt.)对NO_3~-、NH_4~+的吸收动力学特性及其利用差异,探究不同供氮浓度和不同温度条件下刺梨对NO_3~-和NH_4~+的吸收特性,为刺梨氮肥施用提供科学依据。【方法】以‘贵农5号’刺梨品种实生苗为材料,采用耗竭法和砂培试验的方法,测定了供给不同形态及配比的氮素后刺梨实生苗对NO_3~-和NH_4~+的吸收动力学参数及氮素的吸收量与利用效率,研究不同供氮浓度及温度变化和不同硝铵比氮素条件下刺梨实生苗对NO_3~-和NH_4~+的吸收与利用效率的差异。【结果】刺梨根系对硝态氮、铵态氮及总氮的吸收规律均符合Michaelis-Menten酶动力学方程。在不同浓度的NO_3~-、NH_4~+条件下,刺梨根系对NO_3~-的最大吸收速率、亲和力及在根系中的流速始终高于NH_4~+。在硝态氮与铵态氮不同配比的供氮条件下,根系对NO_3~-、NH_4~+的最大吸收速率和NO_3~-、NH_4~+在根系中的流速都随着硝、铵比例的增加而增大,硝铵比为3∶1的供氮条件下,刺梨根系对总氮的吸收速率和总氮在根中的流速最大,最有利于刺梨对氮素的吸收,刺梨实生苗的生物量、总氮的吸收量和氮的利用效率最大。介质的温度过低或过高都会降低刺梨根系对NO_3~-和NH_4~+的吸收,显著降低NO_3~-、NH_4~+的最大吸收速率和NO_3~-、NH_4~+在根系中的流速;无论温度如何变化,刺梨根系对NO_3~-的最大吸收速率和NO_3~-在根系中的流速始终比NH_4~+高。在20~25℃有利于刺梨对NO_3~-和NH_4~+的吸收。【结论】刺梨具有偏好吸收硝态氮的特性,在单纯供给硝态氮或混合供给硝铵态氮硝铵比1∶1及以上的条件下,刺梨实生苗根系对NO_3~-的最大吸收速率、亲和力和NO_3~-在根系中的流速始终比NH_4~+高,刺梨偏好硝态氮的特性不会因介质中NO_3~-和NH_4~+的浓度及温度的变化而改变。介质温度20~25℃有利于刺梨对氮的吸收,供给硝铵比3∶1的氮肥最有利于刺梨实生苗的生长,生物量、氮素吸收量最大,氮素利用效率最高。 相似文献
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恩泰克是在含铵态氮肥料中加入硝化抑制剂的新型肥料,主要通过控制铵态氮向硝态氮的转化,同时提供作物铵态氮及硝态氮。具有速效加长效、改善根际环境、减少硝态氮淋失、提高氮肥利用率、均衡提供氮营养等优势,在农作物上施用后,作物生长健壮、结果多、果实大小均匀、提早成熟,商品性大大增强。 相似文献
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苹果砧木生长及吸收利用硝态氮和铵态氮特性比较 总被引：2，自引：0，他引：2
以一年生平邑甜茶（Malus hupehensis Rehd.）、八棱海棠（M. micromalus Makino）、楸子［M. prunifolia（Willd）Borkh.］、新疆野苹果［M. sievesii（Ledeb.）Roemer］、东北山荆子（M. baccata Borkh.）实生苗为试材,采用15NH4NO3和NH415NO3分别标记的方法,研究5种砧木的生长特性及其对NH4NO3中硝态氮和铵态氮的吸收、分配和利用特性。结果表明：幼苗生物量顺序为楸子 > 平邑甜茶 > 八棱海棠 > 新疆野苹果 > 东北山荆子;根系总表面积、总根长、根尖数均以楸子最大,东北山荆子最小。5种砧木对硝态氮和铵态氮的利用率顺序为楸子 > 新疆野苹果 > 平邑甜茶 > 八棱海棠 > 东北山荆子,5种砧木对硝态氮的利用率均高于铵态氮利用率,并且硝态氮利用率与根尖数呈显著正相关。5种砧木植株各器官从硝态氮中吸收分配到的15N量对该器官全氮量的贡献（Ndff）均高于从铵态氮中吸收分配到的;标记硝态氮时,楸子叶、茎和根的Ndff均最高,平邑甜茶最低;标记铵态氮时,东北山荆子叶、茎和根的Ndff均最高,新疆野苹果叶、楸子茎、平邑甜茶根最低。标记的硝态氮和铵态氮在器官中的分配均为叶 > 根 > 茎。 相似文献
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The effects of combinations of salinity (no salt, 2000 p.p.m. or 4000 p.p.m. of CaCl2 and NaCl, 1:1) and water table (30 cm, 60 cm or 90 cm from the soil surface), on the vegetative growth and tolerance of ‘Golden Japanese’ plum and ‘Mit Ghamre’ and ‘Balady’ peaches were studied. The plants were grown in lysimeters. The growth of the trunk, total shoot length, the increase in shoot length per cm and the fresh weight of top, root and total plant were reduced with increasing salinity of the irrigation water. The effect was accentuated when the plants were maintained at high water table level. The salinity treatments resulted in the death of 43%, 73% and 76% of the plants in the plum, and the ‘Mit Ghamre’ and ‘Balady’ peaches, respectively, indicating that the plum is more tolerant to salinity than the peach. The plants of the salinity treatments showed various symptoms of salt injury, such as leaf burn, defoliation, shoot die-back and finally death. In the peaches, salt injury started to occur in the first growing-season, whereas the salt injury appeared in the plum in the second growing-season. The symptoms were more pronounced in the 4000 p.p.m. treatment than in the 2000 p.p.m. treatment and were more pronounced at the high water table level. The salinity level was the predominant factor and the effect of the water table on the vegetative growth diminished with increase in the salinity level of the irrigation water. 相似文献
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AIM：To establish a fast, accurate and economical technique for culturing mouse pulmonary arteriolar smooth muscle cells (PASMCs), and to explore the effects of hypoxia on the proliferation and apoptosis of the PASMCs. METHODS：In sterile condition, the pulmonary artery was isolated from the male BALB/c mice by digesting with collagenase I, and the cells were cultured in fetal bovine serum-coated flask. Centrifugal procedure was not used during the cell passage. The cell morphology was observed under an inverted phase-contrast microscope. α-Smooth muscle actin was identified by immunocytochemistry and immunofluorescence. The effects of hypoxia on the proliferation and apoptosis of the PASMCs were detected by CCK-8 assay and TUNEL assay. RESULTS：PASMCs were identified by the methods of immunocytochemistry, immunofluorescence staining and observation of morphology. Unlike the rat PASMCs with typical subcultured peak-vally pattern, the mouse PASMCs showed a lot different without a peak-vally pattern. The cells could be subcultured after 5 d to 7 d and there was 3 to 5 generations depending on the activity of the cells. CCK-8 assay demonstrated that the A values of PASMCs exposed to hypoxia increased after 24 h (P＜0.05) as compared with normoxia. TUNEL result showed that the apoptotic index of the PASMCs in hypoxia decreased after 24 h (P<0.05). CONCLUSION：This technique for obtaining cultured mouse PASMCs is simple, fast, accurate and economical. The digestion time is easy to control. Hypoxia promotes the proliferation and inhibits the apoptosis of PASMCs. 相似文献
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小檗碱和壳聚糖抗蔬菜病原真菌活性测定及复合膜制备 总被引：2，自引：0，他引：2
研究了小檗碱和壳聚糖对几种常见蔬菜病原真菌的抑制活性,以及以小檗碱和壳聚糖为主料制备复合膜的方法,并测定了该膜的药物释放效果。试验表明:低浓度(0.234 mg/mL)小檗碱即可抑制辣椒炭疽病菌(Vermicularia capsici)等5种蔬菜病原真菌的生长。20 mg/mL浓度壳聚糖对番茄灰霉病菌(Botrytis cinerea)的抑制率高达65%,而对其余4种果蔬病原真菌也有一定的抑制作用。为了集成这2种天然化合物的优点,制备了小檗碱-壳聚糖复合膜,该膜具有缓释功能,在模拟外部环境(磷酸缓冲液,pH 6.8)条件下,20 d小檗碱累计释放率接近25%,提示其在果蔬贮藏抗菌中的应用价值。 相似文献
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钾肥在小白菜和萝卜上的施用效果 总被引：6，自引：0，他引：6
采用盆栽试验方法研究了施用钾肥对小白菜、萝卜生长发育、产量、品质及钾素含量的影响。结果表明 ,施用钾肥对小白菜和水萝卜的株高、叶片数无显著的影响 ,但可提高水萝卜块根的产量 ,提高幅度为 31.0 4 %～ 97.93%。施用钾肥可提高小白菜和萝卜的蛋白质和VC含量 ,降低硝酸盐含量 ,增加植株的钾素含量 相似文献
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Fresh onion seeds desiccated to 6.0% seed moisture content (SMC) were stored in various packaging materials under different storage conditions. Seeds packed in aluminum-laminated pouches beside those stored with silica gel at 25 °C maintained satisfactory germinability and vigour after 12 months. Desiccated seeds stored in moisture impervious containers produced more vigourous seedlings. Germination potential of onion seeds increased with reduced SMC besides storage in moisture impervious packets along with desiccants as physiological and biochemical attributes are regulated. Seed viability and vigour decreased with accelerated ageing due to increased lipid peroxidation, decreased activities of several free radical and peroxide scavenging enzymes. Electrical conductance of seed leachates also increased with ageing. Thus, adoption of appropriate storage temperature and moisture control techniques would significantly affect onion seed quality, which was due to minimum accumulation of free peroxide radicals and enhanced activity of free radical scavenging enzymes. 相似文献