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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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以黑龙江主栽黄瓜品种"津春3号"为试材,采用盆钵培养的方法,研究了营养液中不同NO3--N与NH4+-N配比对黄瓜幼苗生长及氮、磷养分吸收的影响。结果表明:沙培条件下,营养液中氮的总浓度为15mmoL/L时,随着营养液中NH4+比例的增加,幼苗长势随之变弱;全NO3--N处理的幼苗叶面积、干重及壮苗指数分别是全NH4+-N处理的1.92、2.12与3.07倍;氮形态对幼苗地上部全氮含量与硝酸还原酶活性无显著影响,而对幼苗地上部全磷含量影响显著,全NO3--N处理的幼苗磷含量显著高于全NH4+-N处理,为全NH4+-N处理的2倍;受NH3毒害,全NH4+-N处理的幼苗根系活力显著下降,地上部游离氨基酸含量显著上升。全NO3-处理对黄瓜幼苗生长最有利。 相似文献
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不同氮形态配比对菠菜硝酸盐、草酸含量的影响 总被引：2，自引：0，他引：2
通过水培试验研究了不同氮形态对菠菜硝酸盐、草酸含量的影响.结果表明:在NO3-N/NH4 比例为100/0时菠菜的生物量最大,而随着NH4 比例的增加,菠菜的生物量呈递减趋势,根冠比则在升高.菠菜可食部位的硝酸盐、草酸含量随铵态氮比例的增加逐渐减少,在完全供铵时含量最少.NO3-N/NH4 比为25/75时Vc含量最高. 相似文献
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不同氮素形态配比对百合生长发育的影响 总被引：2，自引：0，他引：2
采用0∶100、10∶90、25∶75、75∶25、100∶0共5个不同铵态氮/硝态氮配比的营养液,对百合进行砂培盆栽试验,研究不同形态氮素配比对百合生长发育影响。结果表明:以硝态氮为主的营养液有利于百合的生长发育,可显著提高各器官的干物质积累以及植株地上部、根部的含N量。其中NH4+-N∶NO3-N=25∶75(N3)处理百合株高、花直径、叶片叶绿素含量、地上部干物质积累、根部N含量积累均达最大值,3个以上花蕾所占比例高,花期最长,说明N3处理的营养液有利于植株生长发育和花器官形成。 相似文献
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氮素形态不同配比对黄瓜生长和性别分化的影响（初报） 总被引：6，自引：0，他引：6
采用基质培养研究氮素形态不同配比对黄瓜生长及性别分化的影响,结果表明用纯NO3--N营养液处理,黄瓜植株营养生长旺盛,当NH4 -N占25％和50％时,黄瓜的生殖生长明显促进,表现为比纯NO3--N处理第一雌花低0.4、0.6节,雌花率增加了23.9％、31.0％,单株产量增加了35.3％、28.7％。叶片和果实中矿物元素钾增加了0.02％～1.41％,铁增加了11～124,ug/g DW,锌增加了37.6～47.0μg/g DW,镁、锰、铜差异不大。黄瓜在不同生育期对氮素形态的敏感性有差异,幼苗期比生长旺盛期不敏感。 相似文献
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番茄根系分泌物、木质部和韧皮部汁液组分对矿质氮和有机氮营养的响应 总被引：3，自引：0，他引：3
采用营养液水培方法探讨了番茄幼苗根系参数、根系分泌物、木质部和韧皮部汁液组分对矿质氮(NH 4-N、NO-3-N)和有机氮(Glycine)的不同响应.结果表明,不同氮素处理8 d后,'申粉918'、'沪樱932'番茄根系干质量、根系体积表现为NO-3-N ＞ Gly-N ＞对照 ＞ NH 4-N处理;而根系活力则表现为以供Gly-N或NO-3-N为最高,其次为供NH 4-N的处理,对照处理最低.不同氮素形态显著影响不同番茄品种根系分泌物、木质部和韧皮部各组分含量. NO-3-N处理的番茄根系分泌物、木质部和韧皮部汁液中的NO-3-N和P含量最高,供Gly-N、NH 4-N其次,对照最低;而供Gly-N、NH 4-N时铵态氮、游离氨基酸、可溶性糖含量一般均高于处理NO-3-N和对照.番茄根际吸收不同氮素对根际pH亦产生不同的影响,吸收NO-3-N和Gly-N后,根际pH显著升高,而吸收NH 4-N后则降低.根系分泌物可溶性蛋白含量的变化表现为NO-3-N ＞ Gly-N ＞ NH 4-N ＞ 对照,而木质部、韧皮部可溶性蛋白含量的变化则表现为Gly-N ＞ NO-3-N ＞ NH 4-N ＞对照.番茄幼苗不同品种间的差异性表现,与氮素形态有关,以根系活力为指标的基因型差异在供应NO-3-N、NH 4-N和Gly-N及对照时,'沪樱932'的根系活力均显著(P＜0.05)大于'申粉918'. 相似文献
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以"791宽叶雪韭"为试材,在完全水培条件下,采用北京市农林科学院蔬菜研究中心研发的新型水培系统进行水培试验,研究了NO3-∶NH4+为12∶0、8∶4、6∶6、4∶8、0∶12五个硝、铵配比营养液对水培韭菜生长生理指标及产量和品质的影响,以期探寻适用于水培韭菜生长的硝、铵配比。结果表明:以产量及生长发育为分析目标,NO3-∶NH4+为8∶4处理适用于水培韭菜生产;以营养品质作为分析目标,NO3-∶NH4+为6∶6和4∶8处理其维生素C含量较高且有较低的硝酸盐累积情况,但这2个处理生长量过低。综合分析,适用于水培韭菜的营养液NO3-∶NH4+为8∶4。 相似文献
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采用营养液培养方法研究氮素形态配比对莴笋产量和品质及养分含量的影响。结果表明:不同处理降低莴笋产量4.5%～13.2%,降低莴笋根重29.8%～48.2%,处理6除外;处理2和处理3莴笋VC含量提高15.6%～16.2%,,处理2增加莴笋可溶性糖含量14.0%,处理4降低莴笋氨基酸含量24.0%;不同氮素形态配比处理均降低莴笋硝酸盐含量达7.5%～42.0%,降低营养中硝态氮比例,增加铵态氮或者酰胺态氮比例提高莴笋全氮含量,对全磷和全钾含量影响不一致。综合分析表明,处理2（NH4+:NO3-=2（Cl）:8）为最佳处理。 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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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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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
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以‘小樱桃’文心兰为材料克隆了铁氧还蛋白氧化还原酶（FNR）两种类型基因RFNR（Root-type Ferredoxin-NADP+ oxidoreductase）和LFNR（Leaf-type Ferredoxin-NADP+ oxidoreductase）。生物信息学分析表明,RFNR与LFNR都属于FNR-like超家族,具有黄素腺嘌呤二核苷酸（flavin adenine dinucleotide,FAD）和烟酰胺腺嘌呤二核苷酸（nicotinamide adenine dinucleotide,NAD）功能结合域,在进化过程中比较保守;两种类型的FNR在氨基酸组成、蛋白结构和构型方面存在明显差异,RFNR比LFNR有更强的保守性。FNR蛋白亚细胞定位结果表明文心兰FNR蛋白都定位于叶绿体。实时荧光定量PCR分析表明,LFNR和RFNR具有器官表达特异性：LFNR更多地在叶中表达,RFNR更多地在根中表达;在软腐病胁迫下LFNR下调响应,RFNR上调响应;两种类型的FNR在盐胁迫以及高温胁迫处理时上调响应,但RFNR响应较快且强度更大;LFNR和RFNR在水杨酸（salicylic acid,SA）处理时轻微波动,茉莉酸甲酯（methyl jasmonate,MeJA）处理时呈现单峰反应。文心兰两种类型的FNR基因在不同类型的胁迫中显示相似的和有区别的表达特性,表明其具有不同的胁迫响应分子机理。 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