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在人工气候培养箱条件下,采用土培试验研究了不同温度(5、15、25℃)对2个普通白菜品种(低富集硝酸盐的揭农4号、高富集硝酸盐的香港特选)生物量、硝酸盐含量、氮代谢关键酶活性以及土壤硝态氮含量、植物-土壤氮代谢关键酶活性的影响。结果表明:15℃是2个普通白菜品种最适生长温度,香港特选和揭农4号的地上部干质量较5℃处理分别增加了23.2%和26.8%。随着温度的升高,香港特选和揭农4号叶片硝酸盐含量显著增加;与5℃处理相比,15、25℃处理的硝酸盐含量分别增加了15.0%、18.3%和6.7%、16.7%。与5℃处理相比,15、25℃处理的香港特选和揭农4号叶片硝酸还原酶(NR)活性增强;亚硝酸还原酶(Ni R)活性和土壤脲酶活性先增加后降低;谷氨酸合成酶(GOGAT)活性总体呈下降趋势;土壤硝酸还原酶活性先下降后上升。随温度的升高,香港特选土壤NO3--N含量逐渐升高,而揭农4号土壤NO3--N含量则显著降低。3种温度处理下,揭农4号叶片和叶柄中硝酸盐含量均低于香港特选。 相似文献
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试验表明,在不施肥的条件下,圆叶菠菜硝酸盐含量显著低于尖叶菠菜,而硝酸还原酶活性高于尖叶菠菜。有机肥和无机肥1:1比例配施处理的菠菜硝酸盐含量最高,其叶片、叶柄、根部的硝酸盐含量与对照相比差异极显著。与叶片、根部相比,叶柄中的硝态氮含量最高,更能说明各处理之间的差异。叶柄的硝酸盐含量与硝酸还原酶活性之间呈显著负相关。叶片中的硝酸还原酶活性最大,根部最小。本试验的亚硝酸盐含量均不超过1.0μg·g~(-1)。本试验表明选择合适的无机肥不仅可以降低生产成本而且可以提高蔬菜品质。 相似文献
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以油菜和诸葛菜幼苗为试材,研究5个光强梯度对其光合电子流传递和叶绿素含量、光合特征、硝酸盐含量、硝酸还原酶活性的影响。结果表明:油菜和诸葛菜的光合电子流传递随光强增加,先缓慢增加后快速上升并达到最大,叶绿素含量、光合速率、硝酸还原酶活性与光强呈正相关,硝酸盐含量与光强呈负相关,诸葛菜和油菜幼苗在光照剂量分别为275和300μmol·s~(-1)·m~(-2)时,光合电子流传递快速增加,硝酸还原酶活性快速增强,硝酸盐含量快速下降,存在一个明显的光照强度拐点,在拐点光照强度之后,油菜和诸葛菜光合电子流传递和硝酸盐含量变化不显著。从经济角度来讲,拐点光照强度即为苗期油菜和诸葛菜的最优光照强度。 相似文献
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以萝卜为试材,分别进行了不同有机无机肥料配施及不同供氯水平对萝卜硝酸盐含量和硝酸还原酶活性(NR)的影响研究,试验结果表明,不同有机无机肥料配施下,追肥一周后随萝卜肉质根膨大硝酸盐舍量呈上升趋势,而NR活性逐渐下降.与不施肥处理相比,不同有机无机肥料配施下萝卜产品器官中硝酸盐、VC、可溶性糖和可溶性蛋白含量显著提高,其中有机肥、化肥分别作基肥和追肥的处理("有+化")具有较低的硝酸盐含量.不同施氮水平下,追肥后随萝卜肉质根的膨大硝酸盐含量呈上升趋势,而NR活性先上升后下降.与不施肥处理相比,萝卜产品器官中硝酸盐、可溶性蛋白含量随施氮量的增加而显著升高,VC和可溶性总糖含量则在常量氮肥处理下达到最大. 相似文献
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钼锰对不结球白菜硝酸还原酶活性及主要营养品质的影响 总被引：1，自引：0，他引：1
采用叶面喷施、根部施用、叶面喷施与根部施用相结合的3种处理方式，研究了钼、锰对不结球
白菜硝酸还原酶活性、硝酸盐含量及营养品质的影响。结果表明，钼能够显著提高不结球白菜的硝酸还
原酶活性，使其硝酸盐含量显著降低；锰对不结球白菜硝酸还原酶活性的影响不明显,但可以显著降低其
硝酸盐含量。钼和锰均可提高不结球白菜可溶性糖和VC含量。与单施钼、锰相比，钼锰配施对降低不结
球白菜硝酸盐含量、提高其可溶性糖和VC含量效果更明显。 相似文献
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有机无机肥配施对大棚黄瓜品质及产量的影响 总被引：7，自引：1，他引：6
以设施大棚黄瓜为试材,进行了有机肥与无机肥不同配比施用对黄瓜品质、产量和硝酸还原酶活性的影响研究.结果表明:在施氮量相同条件下,有机与无机肥的质量分数比为1:4时效应最佳,黄瓜粗蛋白质含量比不施肥处理、有机肥处理和无机肥处理分别增加4.0%、7.4%和3.1%,维生素C含量分别增加13.1%、17.1%和10.2%.各处理间黄瓜产量差异显著,有机无机肥配施处理中随无机肥所占比例增加黄瓜产量提高,无机肥处理比不施肥处理和有机肥处理分别增产36.0%和19.5%,比有机无机肥配施处理的平均增产14.3%.黄瓜硝酸盐含量随无机肥所占比例增加而降低,达到显著负相关水平,无机肥处理的黄瓜硝酸盐平均含量比不施肥处理和有机肥处理分别降低了24.1%和29.4%,比有机无机肥配施处理的平均含量降低了25.6%.有机无机肥配施对大棚土壤硝态氮含量的影响作用较小.黄瓜叶片硝酸还原酶活性与黄瓜硝酸盐含量呈极显著负相关,随配施肥中无机肥所占比例增加黄瓜叶片硝酸还原酶活性提高,是黄瓜硝酸盐含量降低的重要因素. 相似文献
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氮素浓度及形态对韭菜硝酸盐及硝酸还原酶活性的影响 总被引：2，自引：0，他引：2
水培条件下,研究了氮素浓度及氮素形态对"汉中冬韭"体内硝酸盐含量和硝酸还原酶活性的影响。结果表明:随营养液供氮浓度的提高,韭菜叶片硝酸盐含量及硝酸还原酶活性均呈上升趋势;随营养液中铵态氮浓度的增加,韭菜叶片的硝酸盐含量及硝酸还原酶活性均逐渐降低;以硝酸盐作为衡量标准,韭菜适宜的氮肥施用量为4～8 mmol/L,适宜的NO3-←NH4+为1←3～0←4。 相似文献
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十字花科4种蔬菜硝酸盐与亚硝酸盐含量分析与评价 总被引：3，自引：1，他引：2
对十字花科大白菜、甘蓝、花椰菜和青花菜不同品种、不同部位、不同贮藏时间的硝酸盐、亚硝酸盐、VC含量进行分析和评价。结果表明，4种蔬菜以大白菜硝酸盐含量最高，花椰菜最低；同种蔬菜不同品种、同一品种不同部位的硝酸盐、亚硝酸盐、VC含量均存在很大差异。大白菜和甘蓝的硝酸盐含量为外叶>中叶>内叶，叶柄中硝酸盐含量显著高于叶片；VC含量为内叶>外叶>中叶，大白菜叶片中VC含量显著高于叶柄。不同部位的亚硝酸盐含量没有明显规律可循，但外叶的亚硝酸盐含量均最高。通过相关性分析表明，4种蔬菜的硝酸盐含量与VC含量呈极显著负相关。随着贮藏时间的延长，4种蔬菜中的硝酸盐含量均呈先升高后下降的趋势，亚硝酸盐含量均有所升高。 相似文献
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杏果实糖酸组成及其不同发育阶段的变化 总被引：13，自引：4，他引：13
采用高效毛细管电泳仪分离测定了10个杏品种果实中的糖酸组分, 并对新世纪杏与凯特杏不同发育时期糖酸组分的变化进行了研究。结果表明: 各糖组分及总糖含量在品种间都存在较大差异, 但均以蔗糖含量最高, 果糖含量最低; 苹果酸和柠檬酸在品种间差异显著, 根据有机酸组成不同, 可将杏品种分为柠檬酸型和苹果酸型; 在果实不同发育时期, 两个品种果实中总糖含量及各组分的变化趋势基本一致,总糖和蔗糖的含量一直在增加, 而果糖和葡萄糖的含量变化不大。新世纪杏中总酸和苹果酸含量变化趋势完全一致, 都在较高水平上缓慢增加, 而柠檬酸的含量始终很低; 凯特杏中柠檬酸在果实发育前期含量很低, 硬核期结束时含量急剧上升, 成熟前略有下降, 呈“S”型变化曲线, 而苹果酸的变化规律正好与柠檬酸相反, 总的变化趋势呈现反“S”型变化曲线。 相似文献
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The effect of pruning in rose plants (cv. Grand Gala) was studied in different types of leaves, focusing on chlorophyll (Chl) a fluorescence, carbohydrates, ammonium content, nitrate reductase (NR) activity and biomass parameters. Results on pruned plants showed a higher maximum efficiency of photosystem II (PSII) of dark-adapted leaves, a higher actual quantum yield and a higher proportion of PSII reaction centres that are open, but a lower non-photochemical quenching, indicating a lower energy dissipation as heat, compared to non-pruned plants. These results related to Chl a fluorescence, indicate that pruned plants have a higher capacity for better promoting the photosynthetic light reaction than non-pruned plants. The increased nitrate reductase activity in pruned compared with non-pruned plants, can result from a higher photosynthetic activity resulting in a lower NH4+ accumulation in leaves. Pruning promoted a large number of metabolic sinks (flower removal) that may cause depletion of stored carbohydrates flowing from lower plant parts (arched shoots) to the new developing flower shoots. However, although in a lower concentration, carbohydrate contents were sufficient to promote the development of new flower shoots since the yield was similar for pruned and non-pruned plants. However, pruned plants showed higher turgor than non-pruned plants. 相似文献
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Nitric oxide (NO) is a key signaling molecule in different physiological processes of plants. To study the metabolism of endogenous NO in growth and development of apple fruit under normal physiological conditions, the changes of several relative components of NO metabolism including the contents of NO, l-arginine, S-nitrosothiols (RSNOs) and nitrite plus nitrate, the activities of l-arginine-dependent nitric oxide synthase (NOS) and nitrate reductase (NR) were analyzed using vegetal ‘Gold Delicious’ and ‘Fuji’ apples as tested materials. The endogenous NO and l-arginine contents, as well as the l-arginine-dependent NOS activity in young fruit reached the highest value. The NOS activity was dependent on l-arginine and β-NADPH, and inhibited by a well known NOS inhibitor. The NR activity in apple fruit had not been detected. Endogenous NO production depended on l-arginine-dependent NOS but not NR. The content of RSNOs tended to peak in the fruit enlarging period and then declined. Similarly, the nitrate content increased in early stage of fruit growth, but in late stage, it undulated greatly. Compared to RSNOs and nitrate, the change of nitrite content was in accordance with that of endogenous NO. In general, RSNOs and nitrite could reflect the removal mechanism of NO relatively well. 相似文献
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外源水杨酸对韭菜硝酸盐累积及还原同化的影响 总被引：8，自引：1，他引：7
针对韭菜生产中硝酸盐累积问题，研究了叶面喷施水杨酸(SA)对韭菜硝酸盐累积及还原同化的影响。在不同氮素水平下，叶面喷施3.0 mmol·L-1SA后6～9 d可明显降低韭菜叶片硝酸盐含量15.9％～21.6％，而当SA水平达到10.0 mmol·L-1时会加重硝酸盐的积累。叶面喷施3.0 mmol·L-1SA后9 d，韭菜叶片硝酸还原酶(NR)和谷胺酰氨合成酶(GS)活性分别比对照增加了48.9%和40.3％、净光合速率(Pn)和可溶性蛋白含量分别提高了43.4%和21.3％；同时，韭菜叶片谷氨酸草酰乙酸转氨酶(GOT)活性和谷氨酸丙酮酸转氨酶(GPT)活性也均有增加。因此，叶面喷施的外源水杨酸显著提高了氮还原动力泵NR活性以及氮同化动力泵GS活性，同时调动光合作用和转氨作用的积极协同配合，促进了硝态氮转化为游离氨基酸和可溶性蛋白，减少了硝酸盐进入液泡贮积。 相似文献
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R. Gonzalez Ponce M. L. Salas 《The Journal of Horticultural Science and Biotechnology》2013,88(2):254-258
SummaryThe capacity of nitrate absorption, accumulation and reduction was studied in four species of the Solanaceae. Two were cultivated species, tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and two weed species, black nightshade (Solanum nigrum L.) and thorn apple (Datura ferox L.), which often infest these crops. Black nightshade and thorn apple absorbed nitrates most rapidly. Maximum nitrate accumulation was observed earlier in tomato than in the other species, and as in pepper coincided with the flower bud stage. Maximum nitrate accumulation in black nightshade and thorn apple took place during flowering. Only in tomato and thorn apple did maximum nitrate reductase activity occur at the time of maximum nitrate accumulation. Growth and soil nitrate absorption was slowest in pepper, but nitrate accumulation by the plant and nitrate reductase activity was more sustained than in the other species. It was concluded that if these weeds emerge simultaneously with the crops, competition for nitrates by thorn apple, and especially black nightshade, would be greater than for the tomato crop and even more so for the pepper crop. 相似文献