共查询到19条相似文献，搜索用时 750 毫秒
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近年来，国内外学者对蔬菜体内硝酸盐含量进行了大量研究，结果表明：不同种类的蔬菜硝酸盐含量存在差异，一般叶菜类(如菠菜、芹菜)硝酸盐含量较高(1000-2500mg／kg或以上)。但同时也应注意到，同种蔬菜不同品种间硝酸盐积累也存在较大差异。造成蔬菜种类间、品种间硝酸盐积累差异的 相似文献
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通过土培试验,对重金属镉(Cd)处理下不同品种的青菜和白菜地上部的生物量和地上部对镉的吸收积累差异进行了比较研究.结果表明,在100 mg/kg土Cd处理下,青菜和白菜的生长均受到不同程度的抑制作用,其地上部的生物量均显著低于对照,12个参试品种减少率均超过50%,青菜地上部生物量的减少率高达78.45%,表现为较高的敏感性,白菜表现为较强的耐性;镉处理下,不同品种的青菜和白菜对镉的吸收具有显著性差异. 相似文献
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通过溶液培养,对重金属镉(Cd)处理下不同品种的青菜和白菜地上部可食部分的生物量以及对镉的吸收和积累特点进行了比较研究.结果表明:在50μmol/L的Cd处理下,青菜和白菜的生长均受到不同程度的抑制作用,其地上部的生物量均显著低于对照,青菜对Cd具有较强的敏感性,其相对生物量均下降到对照的50%以下,白菜对Cd的耐性高于青菜;镉处理下,不同品种的青菜和白菜对镉的吸收积累具有显著性差异,青菜单位重量的Cd含量明显高于白菜;对青菜和白菜进行了镉耐性和敏感性品种筛选,为无公害蔬菜的种植及镉污染土壤的植物修复提供理论参考. 相似文献
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养分和水分状况对刺梨树体硝酸还原酶活性与氮素营养的影响 总被引：2，自引：0，他引：2
以贵农5号刺梨品种为材料,研究了不同氮素形态供氮条件、营养元素缺素胁迫和不同土壤水分状况下刺梨植株根、茎、叶的硝酸还原酶活性(NRA)及其与总氮及硝态氮含量的关系。结果表明,供应的氮源为30%NO3--NH4+70%NH4+-N时,能够促进刺梨对氮素的吸收,根和叶中总氮含量最高,而NRA并不最强。单纯供应NO3--N时,根和叶中的NRA最强,但总氮含量显著低于同时供应NO3--N和NH4+-N的处理。单纯供应NO3--N和同时供应NO3--N和NH4+-N时,刺梨根和叶中NRA与总氮含量、硝态氮含量呈显著的负相关;同时供应NO3--N和NH4+-N时,刺梨对氮素的吸收并不完全受NR的支配。在缺氮、缺钼条件下,根和叶中都没有检测出NRA;在缺铁、缺硼条件下,根中的NRA很低,叶中没有检测出NRA;其他营养元素缺素胁迫对根和叶中NRA抑制程度的强弱顺序为缺Zn>缺P>缺Mg>缺Ca。根、叶、茎中的NRA与土壤含水量呈极显著正相关,而NO3--N含量则与土壤含水量呈极显著负相关。 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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钼锌与不同肥料配施对大白菜硝酸盐积累及品质的影响 总被引：1，自引：0，他引：1
采用小区试验方法,研究了钼锌与不同肥料配施对大白菜硝酸盐积累及品质的影响。结果表明:添加了钼肥能明显降低大白菜中硝酸盐的含量,单施钼肥对降低硝酸盐的积累最有利;钼锌与不同肥料配施还可以促进白菜生长发育、改善品质及提高产量;钼锌与复合生物肥配施对VC、铁、蛋白质、可溶性糖及叶绿素含量的提高显著;在大白菜种植中最好是施用复合生物肥并根外追施钼锌等微肥。 相似文献
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以"北京铁球小包"和"津青75"2个白菜品种为试材,通过室内土培试验,研究了模拟重金属镉(Cd)污染对邯郸市2个不同白菜品种的生长情况、Cd吸收累积特征及亚细胞分布规律的影响。结果表明:Cd浓度增加抑制了2个白菜品种的生长,在5mg/kg Cd浓度污染下,与对照相比"北京铁球小包"和"津青75"的总干重分别降低了11.3%和40.12%,相对而言,"北京铁球小包"受抑程度低;2个白菜品种所吸收的Cd主要集中于根部,随Cd浓度增加,2个白菜品种对Cd的积累量均提高,在2个Cd污染浓度下,"北京铁球小包"对Cd的总积累量分别比"津青75"高52%和47%,且其根部对Cd的束缚量也较多;综合而言,2个白菜品种中,"北京铁球小包"对土壤Cd的富集能力较强,而其吸收的镉在细胞器中积累较少,且其生长受Cd污染影响较小,在土壤Cd的植物修复具有较强的应用潜力。 相似文献
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Nitrogen plays a major role in the growth and yield of strawberry. For optimizing nitrogen fertilizer application, it is necessary to understand the response of strawberry to nitrogen supply. The objective of this study was to determine the effect of nitrate supply and plant size on strawberry nitrate uptake and nitrate reductase activity (NRA). Strawberry plants cv. Selva were grown under growth chamber conditions in nutrient solutions containing 0, 0.1, 0.25, 0.7 or 4 mM nitrate. Cumulative nitrate uptake increased with the increase in nitrate supply. Increasing nitrate concentrations from 0 to 0.25 mM decreased leaf NRA; however, further increases to 4 mM nitrate restored NRA to activities observed at 0 mM nitrate. The activity of NADH- and NADPH-dependent NR was similar at every external nitrate concentration. Activity of NR was greater in the smallest plants and decreased as plant size increased. However, increasing external nitrate concentration increased nitrate uptake, but had not the same effect on nitrate reductase activity, showing that NRA and nitrate uptake are not necessarily correlated. 相似文献
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The effect of nitrate supply in the nutrient solution on N accumulation was investigated in various organs of MM.106 apple trees (Malus domestica Borkh.). Increasing nitrate supply increased the concentration and amount of total N in leaves and stems, but there was a saturation point of total N accumulation in response to the nitrate supply. The increased accumulation of total N in leaves and stems with increasing nitrate supply were due to increases in reduced N, since nitrate N remained relatively constant. Reduced N contents of trunk bark and trunk wood were significantly decreased when low nitrate was supplied, whereas that of roots was changed insignificantly. Most organs contained only a small portion of their total N as nitrate. The activities of nitrate reductase (NR) were measured using an in vivo assay either with or without nitrate for estimating reduced N accumulation. The in vivo —N03- NR assay may be a better way to estimate the accumulation of reduced N than the in vivo +N03- NR assay since the in vivo +N03- nitrate reductase activity (NRA) was not related to the changes in the reduced N concentration with the differential nitrate supplies. Increasing nitrate supply significant increased in vivo —N03- NRA of all organs. The rate of increase of the in vivo —N03- leaf NRA was greater than those of stems and roots with increasing nitrate supply. Consequently, the proportion of leaf NRA to the total activity increased as the nitrate supply increased. The roots exhibited higher NRA than leaves and stems. The stem also contributed considerably to the total NRA. It can therefore be concluded that the reduction of nitrate can occur in various organs of MM. 106 apple trees as long as nitrate is available. 相似文献
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喷施KNO_3对新高梨实生苗硝酸还原酶活性和氮素积累的影响 总被引：6，自引：0，他引：6
在盆栽条件下,研究了喷施KNO3对新高梨实生苗硝酸还原酶活性(NRA)和氮素积累的影响。结果表明,最高NRA(386.28nmolNO2-/g·hFW)出现在喷施10mmol/LKNO38h后。叶片和根系中(+NO3-)NRA均显著地高于(-NO3-)NRA,其中(+NO3-)NRA与KNO3喷施浓度不存在任何相关性,但(-NO3-)NRA与KNO3喷施浓度呈显著正相关。NRA在茎上各叶位中的分布由顶部向基部逐渐减少。叶片中全氮和还原氮含量随KNO3喷施浓度的增加而增加,但硝态氮含量相对稳定;根系中氮素含量变化与KNO3喷施浓度相关性不明显。叶片和根系中(+NO3-)NRA与氮素含量变化无任何关系;叶片中(-NO3-)NRA与全氮和还原氮含量呈正相关,而根系中(-NO3-)NRA与氮素含量变化不存在任何相关性。因此认为硝酸盐还原在叶片和根系中可能存在不同的酶调控机制。 相似文献
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The purpose of this study was to investigate the effect of glucose on glucosinolates, antioxidants and metabolic enzymes in Brassica sprouts. After glucose treatment, total glucosinolates, phenolics and anthocyanin contents and antioxidant activity were significantly enhanced in Chinese kale and pak choi sprouts, while only the anthocyanin and ascorbic acid contents were increased in radish sprouts. These results indicate that glucose treatment has selectively improved the nutritional compounds in different Brassica sprouts. 相似文献
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Reducing ethylene levels around produce delays the senescence of fruit and vegetables and therefore has the potential to reduce the need for refrigeration during transport and storage, which would result in substantial energy savings. In this study four non-climacteric green vegetables were stored at 0, 5, 10, and 20°C in an atmosphere containing 0.001, 0.01, 0.1, and 1.0 μL L?1 ethylene. The results showed that the postharvest life, as determined by consumer acceptance criteria of yellowing for pak choi and broccoli, leaf abscission for mint, and pod softening and chilling injury for green bean, increased as the temperature and ethylene concentration decreased. Regression equations generated from the storage data allowed for the calculation of the temperature and ethylene levels required for any nominated postharvest life. Using a 14-day postharvest life as an example, storage in ethylene at 0.001 μL L?1 would allow a storage temperature of about 10°C for pak choi, broccoli, and mint and about 18°C for green bean, temperatures well above the current recommendations of 0 to 5°C. 相似文献
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The objective of this study was to determine the effects of nitrogen (N) sources, sulfur (S) and growing seasons on yield and the content of nitrate and vitamin C of broccoli (Brassica oleracea L. spp. Italica). Three N fertilizers (ammonium sulfate, ammonium nitrate and urea) were side-dressed while two levels of sulfur (0.0 and 0.5%) were sprayed on broccoli plants grown in both spring and fall-winter seasons. Here, we report on the interaction between N-source and S supply, yield, and nitrate content and discuss the relevance of this interaction in relation to crop-management strategies under different growing seasons. In the fall-winter season, broccoli yield of “Sultan F1”, “Majestic F1” and “Marathon F1” were 21.23%, 128.52% and 88.53% higher than spring season. Furthermore, S application increased the yield by 9% average over growing seasons, cultivars and N-forms. Also, application of urea as N-source decreased the yield by approximately 13–15% than other N-sources. High curd nitrate accumulation was attributed with spring season and “Marathon F1”, however, less accumulation was found in fall-winter season and “Majestic F1”. Fertilizers containing N forms that not ready available to the crop, i.e. ammonium sulfate and urea, decreased nitrate than fast N-release fertilizer (ammonium nitrate), but their effect on the yield was different. Highest yield with low content of nitrate was achieved when ammonium sulfate combined with sulfur were used during fall-winter season, especially in cv. “Marathon F1”. N-source and sulfur application had no effect on vitamin C, conversely, it was affected by growing season and tested genotypes. Therefore, additions of ammonium sulfate and sulfur application in the field of broccoli were essential to produce higher yield with good quality curds that pose minimum health risk to human. 相似文献
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不同浮面覆盖材料对小白菜和菠菜产量的影响 总被引：4，自引：0，他引：4
通过无纺布、遮阳网对冬季蔬菜浮面覆盖的试验表明,２０、３０、４０ｇ／ｍ２无纺布、２５ｇ／ｍ２粘纺布和ＳＺＷ１０型银灰色遮阳网的透光率,分别为８７％、７９％、７３％、７２％和５５％。覆盖后土壤含水量比对照增加５１．４１％～１２．４６％,其中以２５ｇ／ｍ２粘纺布保湿性最好,其次是４０ｇ／ｍ２无纺布。２０ｇ／ｍ２无纺布覆盖增温效果明显,地面温度比不覆盖的对照增加０．８～２．６℃,５～２０ｃｍ土层无论晴天、阴雨天均有增温趋势,尤其是５ｃｍ土层增温达１．８℃。浮面覆盖对矮脚黄小白菜的生长有明显的促进作用。增产效果明显,其规律为３０ｇ／ｍ２无纺布＞２０ｇ／ｍ２无纺布＞２５ｇ／ｍ２粘纺布＞４０ｇ／ｍ２无纺布＞ＳＺＷ１０型银灰色遮阳网,对菠菜的增产效果类同矮脚黄小白菜。 相似文献
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为评价紫叶生菜和绿叶生菜的营养价值,选取紫叶生菜和绿叶生菜品种各4个,分别测定、比较了其可溶性糖、可溶性蛋白、维生素C、硝酸盐和花青素含量。试验结果表明,绿叶生菜(GT)品种可溶性糖含量整体均高于紫叶(VT)品种,平均高112.9%;整体上VT与GT的硝酸盐含量差异不大,其中VT中深紫色的VT_1硝酸盐含量显著高于其他品种,GT中深绿色的GT1硝酸盐含量高于其他品种;所有VT品种的可溶性蛋白、维生素C以及花青素含量均高于GT品种,其中VT品种的可溶性蛋白和维生素C含量分别比GT的高80.6%、33.4%。另外,只有紫叶生菜含有花青素,其中深紫色的VT1花青素含量最高,随叶色变浅而逐渐降低。以上结果说明绿叶生菜品种可溶性糖含量显著高于紫叶品种,且较紫叶生菜口感好,但紫叶生菜的可溶性蛋白、维生素C以及花青素含量高于绿叶生菜。 相似文献