共查询到20条相似文献，搜索用时 15 毫秒
1.
采用外源硒加入土壤中得到硒污染土壤,6种有效硒的浸提剂NaHCO3、KH2PO4、K2SO4、EDTA、AB-DTPA和DTPA＋TEA＋CaCl2的最佳浸提时间和土液比进行了筛选,并通过盆栽试验对所选择的土壤有效硒浸提剂进行生物学校验,以找出石灰性土壤有效硒提取适宜的浸提剂及其浸提条件。结果表明,NaHCO3、KH2PO4、K2SO4、EDTA、AB-DTPA和DTPA＋TEA＋CaCl26种浸提剂有效硒浸提量都随着浸提土液比的减小而增大,且随浸提时间的增长而增大。其中NaHCO3和KH2PO4最佳土液比为1/15,振荡时间90min;K2SO4和AB-DTPA的最佳土液比为1/15,振荡时间60min;EDTA和DTPA＋TEA＋CaCl2的最佳土液比则为1/20,振荡时间30min。6种浸提剂在各自最佳的提取条件下提取的土壤有效硒量与白菜地上部分硒含量达极显著正相关,但土壤有效硒的提取量以DTPA＋TEA＋CaCl2及K2SO4最少,只占KH2PO4、AB-DTPA及EDTA提取量的14%～48%,故不适用于作为石灰性土壤有效硒的提取剂。NaHCO3适用于土壤硒含量高于5mg·kg^-1的石灰性土壤有效硒提取。KH2PO4、AB-DTPA及EDTA3种浸提剂既可提取土壤中水溶态硒,亦可提取部分的吸附态硒,提取硒数量较多,过程简单,重复性好,都可作为石灰性土壤有效硒提取的浸提剂。 相似文献
2.
《Communications in Soil Science and Plant Analysis》2012,43(10):1195-1204
The stimulative action and detoxifying effect of selenium on garlic growth under cadmium stress were investigated. Selenite treatment can promote mitosis of garlic root-tip cells and growth of roots and seedlings. Garlic has a strong ability to accumulate the selenium from soil, and selenium content was greatest in garlic seedlings. Addition of selenite at a concentration of 2.0 μg kg?1 in soil could decrease cadmium content in garlic and protect the seedling growth. The selenium has been shown to have an effective protective role on garlic growth under cadmium stress. 相似文献
3.
《Communications in Soil Science and Plant Analysis》2012,43(22):3465-3482
In soil, adsorption of selenium (Se) onto mineral surfaces is accompanied by poorly known retention via organic matter. The effects of these components on the availability of Se were examined in two pot experiments. Spring wheat was grown with increasing amounts of selenate (SeO4 2–) in one sand and three peat soils, and ryegrass with selenate and selenite (SeO3 2–) in sphagnum peat manipulated by iron (Fe) hydroxide. Selenate persisted in soluble form, whereas selenite was fixed in the soil. In wheat, 5–50% of the selenate addition was recovered in the plant, the proportion increasing with increasing Se. In ryegrass, 30–40% of the added selenate but less than 2% of the selenite was found within the leaves. The Fe hydroxide enrichment enhanced the selenite uptake. Phosphate buffer desorbed a minor proportion of the added selenite, except in peat amply enriched with Fe hydroxide. The results suggest that the retention mechanism of selenite was changed due to the hydroxide amendment. 相似文献
4.
5.
pH和三种阴离子对紫色土亚硒酸盐吸附-解吸的影响 总被引：2，自引：0，他引：2
p H和三种竞争性阴离子对紫色土亚硒酸盐吸附-解吸的影响的研究结果表明,随着p H的增大,紫色土对亚硒酸盐的吸附量减少,酸性条件下紫色土对亚硒酸盐吸附量最大。平衡液中加入磷酸氢二钠显著降低了土壤对亚硒酸盐的吸附,硫酸盐对紫色土吸附亚硒酸盐的影响很小,低浓度碳酸氢根离子对紫色土吸附亚硒酸盐具有促进作用,但高浓度的碳酸氢根离子则降低了紫色土吸附亚硒酸盐。磷酸氢根离子和硫酸根离子对亚硒酸盐吸附的影响符合Langmuir和Freundlich拟合方程式,决定系数R2值均在0.90以上。三种阴离子对亚硒酸盐的解吸影响不同,当有磷酸氢根离子和碳酸氢根离子存在时,亚硒酸盐的解吸率增大,而硫酸根离子的存在却对紫色土亚硒酸盐的解吸影响不大。在紫色土地区农业生产中采用含磷酸盐肥料和碱性碳酸氢铵肥料,这些措施可能增加土壤硒的有效性,进而增加植物硒吸收和积累。认识紫色土固液界面硒的吸附-解吸规律,可为提高紫色土地区硒生物有效性,从而进一步提高农产品中硒含量提供科学依据。 相似文献
6.
Hidekazu Yamada Yumei Kang Tomonori Aso Hiroshi Uesugi Tomokazu Fujimura Koyo Yonebayashi 《Soil Science and Plant Nutrition》2013,59(3):385-391
The chemical forms of selenium (Se) in soils derived from different parent rocks, and the stability of Se species in soils were investigated. Around 40% of the total Se occurred as organic Se on the average. Total selenite content was higher than that of total selenate. The content of organic Se decreased with heating of the soils at high temperatures, and most of it disappeared at heating temperatures above 500°C. However, the results of incubation experiments indicated that Se species were stable in soil, and that their chemical forms did not change appreciably with the variation of soil conditions. In soluble Se, organic Se accounted for about 50%, and in contrast to the total Se, the selenate content was higher than that of selenite. 相似文献
7.
Martin Urík Marek Bujdoš Katarína Gardošová Pavol Littera Peter Matúš 《Water, air, and soil pollution》2018,229(2):52
Selenite is an environmental toxicant whose mobility is affected in soil by various natural components, including humic acids, clay minerals, amorphous ferric oxyhydroxides [FeOx(OH)y], and microorganisms. However, interactions of selenite with these components are usually evaluated separately. Therefore, we addressed selenite behavior in multicomponent system in this study with emphasis on its immobilization and fungal accumulation. Our results highlighted significant acidification of culture medium by common soil fungus Aspergillus niger’s production of protons in selenite presence which affected selenium immobilization. While bentonite and humic acids did not enhanced immobilization efficiency significantly, composite of FeOx(OH)y/humic acids was extremely successful in selenium immobilization. This was most likely by enhanced redox transformation of selenite into elemental selenium as the contribution of each component was synergistic. Subsequently, selenium bioavailability in culture medium decreased and negatively affected bioaccumulation efficiency by fungus. Our results highlighted the significance of multicomponent systems in more realistic evaluation of selenium mobility and transfer to microorganisms. 相似文献
8.
考察了发酵条件对产朊假丝酵母富硒能力的影响。通过单因素的筛选,对酵母富硒能力影响较大的3个因素:亚硒酸钠浓度、初始p H值及培养温度,以胞内总硒含量为响应值,利用响应面法对其进行优化。结果显示:在培养时间30 h、加硒时间对数生长中期、亚硒酸钠浓度35 mg·L-1,初始p H 6.6、接种量10%、培养温度27℃、装液量150 m L/500 m L的条件下,最大的菌体生物量为6.87 g·L-1;胞内总硒含量达到12 639.7μg·L-1,硒含量为1 839.8μg·g-1,其中亚硒酸钠转化率为79.1%,有机硒含量占90%以上;胞内实际总硒含量与数学模型理论值12 518.8μg·L-1相差不显著,响应面法能较好地优化产朊假丝酵母富硒工艺条件。 相似文献
9.
B.-M. Wilke 《植物养料与土壤学杂志》1985,148(2):183-192
Adsorption of selenite on different types of forest humus In the present investigation the adsorption of selenite selenium on L-, O-, and A-horizons of the humus forms mull, moder, and mor was studied. Selenite adsorption decreased in the order mull > moder > mor. The organic layers adsorbed nearly the same amount of selenium as the underlying A-horizons. Among the L- and O-layers selenadsorption increased with increasing pH. Amounts of organic carbon, “free” oxides did not influence the adsorption capacity. The Freundlich equation was valid to describe selenite adsorption of all layers under investigation. Additionally the Langmuir equation fitted the adsorption curves of the mull soil and the moder L-horizon. Adsorption experiments using perfusion apparatuses showed microorganismus to incorporate high amounts of selenite under natural conditions. 相似文献
10.
利用盆栽试验,研究了不同浓度、不同价态外源硒（Se4＋、Se6＋）对连续种植小白菜土壤中过氧化氢酶、脱氢酶、脲酶和碱性磷酸酶活性的影响,为土壤硒污染的生态风险评价和管理提供科学依据。结果表明：低浓度硒对土壤酶活性有不同程度的激活效应,而高浓度硒对4种土壤酶均产生抑制作用;外源硒对脲酶及脱氢酶活性的抑制作用大于碱性磷酸酶和过氧化氢酶。外源Se4＋及Se6＋浓度与土壤脲酶活性间都存在显著的负相关（P〈0.01）,且同浓度两个价态硒差异显著（P〈0.05）,说明脲酶可作为土壤硒污染程度的生态风险评价的生物指标;而过氧化氢酶、脱氢酶及碱性磷酸酶只能表征一定时间段内土壤硒污染的程度。土壤酶的ED5（0生态剂量）均随硒施入时间的延长而增大,以脲酶的ED50值最小,Se6＋的ED50小于Se4＋,生态毒性大于Se4＋。 相似文献
11.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):2303-2318
In this work, the relationship among accumulation of selenium, auxin, and some nutrient elements [magnesium (Mg2+), iron (Fe3+), manganese (Mn2+), copper (Cu2+), zinc (Zn2+)] in tissues of roots, mesocotyls, and leaves of Zea mays L. plants was studied. Seeds of maize were cultivated for 4 days in the darkness at 27 °C on moist filter paper, then the individual seedlings were transferred into an aerated solution containing the macro‐ and microelements and were cultivated in a greenhouse for 12 h in the light and 12 h (12‐h photoperiod) in the dark at 25 °C. The seedlings were exposed to the solution containing sodium hydrogen selenite (NaHSeO3), indole‐3 acetic acid (IAA), or IAA+NaHSeO3 for approximately 96 h before chemical analysis. The concentration of IAA in the external medium was 10?4 mol dm?3, concentration of selenite (NaHSeO3) was 10?6 mol dm?3, and the pH of the medium was 6.5. The accumulation of the probed elements in seedlings of maize was measured by inductively coupled plasma optical emission spectroscopy (ICP‐OES). It was determined that the selenite and IAA, present in the external medium of growing plants, changed the uptake and accumulation of some cations in tissues of leaves, mesocotyls, and roots. The change of transport conditions of these nutrient elements is probably one of the first observed symptoms of selenium effects on plants. 相似文献
12.
从广西钦州市钦北区的富硒土壤中筛选出一株可高效还原亚硒酸盐的细菌QZB-1。16S rDNA基因序列分析确定菌株为粘质沙雷氏菌(Serratia marcescens)。研究发现菌株QZB-1可耐高达180 mmol/L的亚硒酸盐。进一步研究发现菌株QZB-1在36 h之内对1 mmol/L亚硒酸盐的还原率为95%，随着硒浓度升高还原率有所下降。正交实验表明，对菌株还原亚硒酸盐的影响程度依次是初始亚硒酸盐浓度>培养时间>接种量，最佳还原条件是初始亚硒酸盐浓度为1 mmol/L，接种量为10%，培养时间为36 h，此时菌株QZB-1对亚硒酸盐的还原率大于98.55%。研究结果表明新型亚硒酸盐还原菌粘质沙雷氏菌QZB-1可高效还原亚硒酸盐为单质纳米硒，可高效应用于亚硒酸盐污染水体和土壤的治理。 相似文献
13.
水稻不同品种在海南富硒土壤中硒的吸收和分配机理 总被引：8，自引：0，他引：8
利用盆栽研究了5个水稻品种在两种不同的富硒土壤中Se吸收累积的生育期动态变化和Se在水稻植株不同部位的分配机理.结果表明,随着生长发育期的推进,水稻在孕穗期对Se含量和累积量同时骤增,从苗期到孕穗期水稻Se的累积量占总Se累积量的45.5%～67%,同时Se含量也达到最高,说明这一段时期是水稻吸收Se的关键时期;在富硒土壤1中水稻各器官Se含量都显著大于相应土壤2中水稻各器官,水稻各器官Se含量顺序依次为根>叶>茎>籽粒,Se易向营养体富集;5个水稻品种中只有杂交稻在土壤1中生长正常;3个常规水稻中旱14、2004-95、稻翅品种在土壤2中的SOD、POD酶活性比土壤1中呈明显减小趋势,但杂交稻特优10 SOD酶活性变化相反,其POD酶活性变化的幅度也最小;在土壤2中5个水稻品种生长都正常,杂交稻的平均硒含量最低,但累积量最高. 相似文献
14.
潮土中水溶态硒和交换态硒含量变化的试验研究 总被引：3，自引：1，他引：2
在富硒潮土中施加磷酸二氢钙和硫磺,进行室内模拟试验,分析了土壤中水溶态硒和交换态硒含量的变化.结果表明,在潮土中施加磷酸二氢钙和硫磺对土壤中的水溶态硒含量变化影响不显著,适量施加磷酸二氢钙可提高土壤中交换态硒含量,施加硫磺的提高作用稍弱;施加0.12%的磷酸二氢钙,或者施加0.12%磷酸二氢钙加0.011%硫磺的方式,能有效地提高潮土中交换态硒的含量.试验结果对合理利用含硒土壤资源,科学施肥,开发富硒农产品具有指导意义. 相似文献
15.
用盆栽试验研究了不同浓度外源硒（四价和六价）处理土壤对小麦生长和生理代谢的影响,旨在为富硒小麦的种植和开发提供理论依据。结果表明：外源硒抑制了苗期小麦的生长（株高和生物量）;而在生长后期,随外源硒浓度增加表现为先促进后抑制作用。Se（Ⅳ）和Se（Ⅵ）处理对小麦生物量影响的EC10分别从苗期的1.40mg·kg-1和0.28mg·kg-1增加到收获期的28.48mg·kg-1和4.56mg·kg-1,表明小麦对硒的耐受浓度随生长时间的延长逐渐增大。Se（Ⅵ）低浓度（≤1mg·kg-1）对小麦生长的促进作用及高浓度（≥2.5mg·kg-1）对小麦生长的抑制作用均大于Se（Ⅳ）。小麦籽粒产量随外源Se（Ⅳ）和Se（Ⅵ）浓度的增大先升高而后降低,分别在2.5mg·kg-1和1mg·kg-1浓度处理时达到最大。低浓度硒处理（Se（Ⅳ）≤5mg·kg-1和Se（Ⅵ）≤0.5mg·kg-1）能促进拔节期小麦叶片中GSH和POD等抗氧化酶活性,显著降低叶片过氧化物质MDA（Se≤2.5mg·kg-1）含量,高浓度硒处理则与之相反。 相似文献
16.
Rye-grass was grown in six different soils with four additions of 75Se-labelled selenite through six cutting in a pot experiment. Following the last cutting, the soils were extracted with a series of solvents to fractionate the residual soil selenium. The plant content of added and total selenium was determined. The results showed that equilibrium between added and native selenium was obtained before the third cutting, giving a nearly constant LSe-value for the last four cuttings. The LSe-values differed between the soils, and there was a positive correlation between the LSe-values and the plant uptake of native selenium. In accordance with this, the best correlation with the total selenium concentration in the plants was obtained with the isotopically exchangeable selenium in the soil after the last cutting. It is concluded that isotopically exchangeable selenium approximates the fraction of soil selenium from which plant uptake of selenium occurs. 相似文献
17.
以赤子爱胜蚓为生物载体,在蚯蚓饲料中添加亚硒酸钠进行富硒蚯蚓培养试验,利用蚯蚓的生物富集作用将无机硒转化为有机硒。以存活率、硒含量为优化指标,研究5种硒浓度(20、40、60、80、100 mg·kg-1)和4种培养时间(第15、30、45、60 d)对蚯蚓生长和硒含量的影响规律,筛选存活率高、硒含量高、培养时间短的富硒蚯蚓培养方法。试验结果表明:蚯蚓饲料中亚硒酸钠含量越高、培养时间越长,蚯蚓的存活率越低,硒含量越高,且当硒添加量为80 mg·kg-1,培养时间为45 d时,培养条件最优,此时蚯蚓体内硒含量可达33.25 mg·kg-1。 相似文献
18.
Poggi V Arcioni A Filippini P Pifferi PG 《Journal of agricultural and food chemistry》2000,48(10):4749-4751
The effect of a foliar spray of selenium on potatoes was investigated for 2 years. Amounts of 0, 50, and 150 g of Se ha(-)(1) were applied both as sodium selenate and as sodium selenite in water, either pure or with the addition of 0.15% of soluble leonardite as a source of humic acids (pH 7). Tuber selenium concentration increased with the application levels, both with sodium selenate and with sodium selenite, when only aqueous solutions were used. When humic acids were added, the tuber selenium level rose more markedly after the application of sodium selenate as compared to the case of the aqueous solutions; however, in the case of sodium selenite, the level showed a large increase only after the application of 50 g of Se ha(-)(1). Kinetics showed that humic acids raised the selenate availability, but no differences were found in the distribution of selenium in the tuber fractions. Foliar application of selenium with humic acids was proven to be a good way to increase the selenium content of potatoes, but the assimilation process of selenium was simpler with selenate than with selenite. 相似文献
19.
阐述了植物对不同形态硒的吸收、转运和形态转化机制。植物主要吸收水溶性硒,包括部分有机硒、硒酸盐和亚硒酸盐。多数研究表明植物对硒酸盐的主动吸收是通过高亲和力的硫酸盐转运子完成,最近的研究表明磷酸盐可以调节亚硒酸盐的吸收,磷酸盐转运子在亚硒酸盐的主动吸收过程中有重要作用;植物吸收的硒酸盐很快从根部转移到地上部,在叶片中被还原成亚硒酸盐,进而转化为有机硒化物进入其他组织;而亚硒酸盐及其代谢产物主要积累在根部,极少转移到地上部。进入植物体中的硒转化为含硒氨基酸和硒蛋白参与植物的代谢。 相似文献
20.
Li HF Lombi E Stroud JL McGrath SP Zhao FJ 《Journal of agricultural and food chemistry》2010,58(22):11837-11843
Rice (Oryza sativa) is the staple food for half of the world's population, but the selenium (Se) concentrations in rice grain are low in many rice-growing regions. This study investigated the effects of water management on the Se speciation dynamics in the soil solution and Se uptake and speciation in rice in a pot experiment. A control containing no Se or 0.5 mg kg(-1) of soil of selenite or selenate was added to the soil, and plants were grown under aerobic or flooded conditions. Flooding soil increased soluble Se concentration when no Se or selenite was added to the soil, but decreased it markedly when selenate was added. Selenate was the main species in the +selenate treatment, whereas selenite and selenomethionine selenium oxide were detected in the flooded soil solutions of the control and +selenite treatments. Grain Se concentration was 49% higher in the flooded than in the aerobic treatments without Se addition. In contrast, when selenate or selenite was added, the aerobically grown rice contained 25- and 2-fold, respectively, more Se in grain than the anaerobically grown rice. Analysis of Se in rice grain using enzymatic hydrolysis followed by HPLC-ICP-MS and in situ X-ray absorption near-edge structure (XANES) showed selenomethionine to be the predominant Se species. The study showed that selenate addition to aerobic soil was the most effective way to increase Se concentration in rice grain. 相似文献