首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
The effect of selenium (Se) treatments on potato growth and Se, soluble sugar, and starch accumulation was investigated. Potato plants were cultivated in quartz sand without or with sodium selenate (0, 0.075, 0.3 mg Se kg(-1) sand). In young potato plants, Se treatment resulted in higher starch concentrations in upper leaves. The tuber yield of Se-treated potato plants was higher and composed of relatively few but large tubers. At harvest, the starch concentration in tubers did not differ significantly between treatments. The higher Se addition (0.3 mg Se kg(-1)) may have delayed the aging of stolons and roots, which was observed as high concentrations of soluble sugar and starch. Together with the earlier results showing elevated starch concentration in Se-treated lettuce, the findings of this research justify the conclusion that Se has positive effects also on potato carbohydrate accumulation and possibly on yield formation.  相似文献   

2.
采用温室大棚试验,研究了叶面喷施硒酸钠和亚硒酸钠对提高草莓硒含量的影响以及硒在草莓植株中的转运和分布,旨在为富硒水果的开发和生产提供理论依据。本试验在草莓初花期进行叶面喷施亚硒酸钠和硒酸钠,当喷硒量为20、40、60 g Se·hm~(-2)时,亚硒酸钠处理40 d后草莓果实样品中硒含量分别为0.03、0.10、0.15 mg·kg~(-1)FW,分别为对照的3、20倍和30倍;硒酸钠处理40d后草莓果实硒含量分别为0.05、0.12、0.17 mg·kg~(-1) FW,是对照处理的5、24倍和34倍。但是叶面喷施的硒持续供给果实的能力有限,随着草莓果实的连续生长,后期采收的草莓中硒含量显著下降。叶面喷硒后,叶片吸收的亚硒酸钠约有30%转移到了根部,而硒酸钠则更多地累积于叶片中,转移到根部的量不到15%。草莓初花期叶面喷施硒可以显著提高前期草莓果实中硒的含量,随着采收期的延长,草莓中硒的含量显著下降,喷施亚硒酸钠的处理硒向根部转移的能力高于硒酸钠的处理。  相似文献   

3.
In a greenhouse experiment, Brassica plants were grown in an alkaline sandy loam soil treated with different levels of selenate selenium (Se) or selenite Se ranging from 0 to 4 mg Se kg?1. Plants grown in Se-treated soil were stressed at an early stage of pod setting and produced fewer pods per plant. Selenium accumulation increased by 2- to 35-fold in shoots, 3- to 19-fold in roots, and 2- to 57-fold in grains. Selenium accumulation in grains resulted in significant increases in contents of reducing sugars, starch, glucosinolate, and free and sulfur-containing amino acids and a decrease in lipid content. Selenium accumulation significantly increased the proportions of different lipid classes such as glycolipids, sterols, and free fatty acids whereas triacylglyceride content showed the reverse trend. Oil extracted from Brassica grains grown in the seleniferous region contained Se within safe limits and thus is safe for human consumption.  相似文献   

4.
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   

5.
In a greenhouse experiment, wheat cultivars PDW 291, PBW 550, and TL 2908 were grown in alkaline sandy-loam soil treated with sodium selenate at 0, 2, and 4 mg selenium (Se) kg?1 soil. Selenate-treated wheat plants accumulated greater Se in roots, stems, leaves, and grains and showed growth retardation, snow-white chlorosis, decreased shoot length and chlorophyll, and reduced leaf area and produced less number of grains as compared to control plants. Maximum reduction in these parameters was observed in selenate-treated TL 2908 plants and most of the plants died before maturity with almost no grain formation with 4 mg Se kg?1 soil. Selenium accumulation resulted in decreased reducing sugar, starch, and protein contents in grains whereas total free amino acids increased significantly in all the three cultivars. Selenium accumulation in wheat showed metabolic disturbances and its accumulation in grains was beyond toxic levels, thus making it unfit for consumption.  相似文献   

6.
Due to selenium (Se) deficiency, Se fortification of food and feed is applied in many countries. Therefore, potential use of Se‐enriched kenaf was investigated based on its Se accumulation, its potential to transform accumulated Se to other Se species, and effect of Se accumulation on its growth. Kenaf was grown with different levels of two Se fertilizers (selenite and selenate) at concentrations ranging from 0 to 4 mg Se (kg soil)–1. Total Se concentrations in the plants grown on selenate‐treated soil amounted to (1019 ± 136) mg Se (kg dry weight)–1 and were much higher compared to plants grown on selenite‐treated soil. Identified Se species were selenite, selenate, Se‐methionine, and Se‐cystine. Biomass yield, net photosynthesis, and chlorophyll index of the plants decreased when plants were grown on soils treated with high doses of selenate.  相似文献   

7.
不同形态硒向水稻籽粒转运途径及品种差异   总被引：3，自引：0，他引：3  
硒是人体必需微量元素,提高水稻籽粒硒含量对改善人体膳食硒营养有重要意义。以富硒水稻品种(Oryza sativa L.)秀水48和非富硒品种S.Andrea为材料,在灌浆期分别供应离体穗亚硒酸盐、硒酸盐、硒代蛋氨酸(SeMet)和硒甲基硒代半胱氨酸(SeMeSeCys),探讨两品种水稻在灌浆期向籽粒转运不同形态硒的品种差异及转运途径。结果表明:水稻体内有机硒主要通过韧皮部转运至籽粒,硒酸钠可能通过木质部和韧皮部共同转运至剑叶,而亚硒酸钠主要通过木质部转运至剑叶。秀水48从茎至籽粒转运硒酸盐和硒代蛋氨酸能力显著强于S.Andrea,并且富硒水稻秀水48从剑叶至籽粒转运有机硒(硒代蛋氨酸)能力显著高于S.Andrea。与非富硒水稻相比较,富硒水稻能通过茎和剑叶向籽粒转运较多的硒,这可能是引起水稻籽粒硒含量差异的直接原因。  相似文献   

8.
王琪  王雅琦  万亚男  李花粉 《土壤》2022,54(6):1101-1107
通过田间试验,研究了不同形态叶面硒肥对水稻吸收和转运硒的影响。与空白对照相比,亚硒酸钠、硒酸钠、硒代蛋氨酸和化学纳米硒在水稻扬花期一次施用(15g/hm2)可使水稻籽粒、颍壳和秸秆的硒含量分别提高0.06～0.64、0.36～0.83和0.32～0.75 mg/kg。籽粒硒的回收率大小顺序为：硒代蛋氨酸(34.6%)>亚硒酸钠(15.7%)>硒酸钠(15.0%)>化学纳米硒(6.6%);硒在水稻各部位中的分配比例的高低顺序为：秸秆>籽粒>颍壳。此外,硒用量与水稻籽粒的硒含量呈极显著线性相关。按照黑龙江省富硒大米的地方标准(DB23T 790—2004),达到一等大米的硒含量指标(0.20～0.30 mg/kg),亚硒酸钠单施的施用量为6.01～10.62 g/hm2,腐植酸+亚硒酸钠复合肥的施用量为4.26～8.63 g/hm2。硒代蛋氨酸的富硒效率高于其他3种硒形态,腐植酸+亚硒酸钠复合肥的富硒效率高于亚硒酸钠单施。  相似文献   

9.
臧倩  王光华  张明静  胡雪  徐承昱  蒋敏  黄丽芬 《核农学报》2022,36(10):2072-2083
为探讨不同肥料处理下抽穗期高温胁迫对水稻籽粒淀粉酶活性及淀粉品质形成的影响,本试验以优质食味水稻南粳9108为材料,设置施用有机肥(OF)和常规化肥(CF)处理,于抽穗期进行常温(NT)、+2℃(较常温增加2℃,MT)和+5℃(较常温增加5℃,HT)处理,对籽粒淀粉合成特性进行研究。结果表明,抽穗期温度升高降低了蔗糖合成酶(SS)、淀粉合成酶(SSS)和淀粉分支酶(SBE)的活性,提高了蔗糖磷酸合成酶(SPS)和焦磷酸化酶(AGP)的活性。蔗糖含量、淀粉平均粒径、热焓值与峰值温度均表现为HT>MT>NT;淀粉含量、直链淀粉含量与黏度值则随着温度升高而下降。在肥料处理方面,各淀粉相关酶活性均表现为OF>CF,且在OF处理下有较好的淀粉品质。综上所述,温度升高通过抑制淀粉合成,加速了形成淀粉原料的积累,进而导致籽粒中蔗糖含量升高;有机肥处理能促进蔗糖合成并提高淀粉合成相关酶活性。从气候变暖应对措施方面,可选择有机肥替代化肥调控淀粉相关酶活性,进一步改善淀粉品质。本研究结果为减少高温对水稻的危害与提高淀粉品质提供了技术参考。  相似文献   

10.
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   

11.
Large areas of China have soils low in both available selenium (Se) and zinc (Zn). In order to investigate whether Se supplied as either selenate or selenite can increase germination and growth compared with low-Se controls we used broccoli, an important vegetable with anticancer effects, especially when biofortified with Se. Broccoli was grown under both Zn adequacy and Zn deficiency to determine whether interactions between these minerals affect plant growth. Selenite and selenate at a wide range of doses increased the speed and extent of germination. Both inorganic Se forms increased early root and shoot growth at low concentrations, with selenite having a stronger effect than selenate. A sand culture trial showed a similar growth increase due to low-dose Se under Zn deficiency but not under Zn adequacy. Conversely, at high Se levels, the results provided evidence from biomass, water use, photosynthesis and gas exchange that broccoli growth was inhibited at high Se levels, with selenite being more toxic than selenate. In this broccoli trial, the two Se forms were equally effective in increasing leaf Se concentration, whereas in most plants selenite is largely converted to organic Se forms and stored in the roots. This study suggests that Se, supplied either as selenate or selenite, may improve germination and growth in broccoli, especially on Zn-deficient soils. Field trials conducted on soils which are very low in both plant-available Se and Zn are needed.  相似文献   

12.
紫甘薯对硒的吸收和累积特征   总被引：3，自引：0，他引：3       下载免费PDF全文
以紫甘薯为试验材料,采用盆栽试验的方法研究了基施硒酸钠[Se(VI)]和亚硒酸钠[Se(IV)]条件下,紫甘薯对外源硒的吸收累积规律,并比较了施用两种不同价态硒的紫甘薯富硒效果。结果表明:两种硒源均可显著提高紫甘薯各器官含硒量,且紫甘薯含硒量均随施硒量的增加而增大。当土壤施硒量为Se 8 mg/kg时,施用硒酸钠、亚硒酸钠收获期薯块的硒含量(干基)分别达到6.69、0.88 mg/kg。紫甘薯生育期40 d时各器官硒含量叶茎薯块,130 d时硒含量叶薯块茎。当硒酸钠施用量为Se 4 mg/kg时,紫甘薯薯块中的硒累积量最高达923.81μg/株,硒在紫甘薯块根中的分配率可达67%~70%,硒酸钠处理下,紫甘薯对硒的吸收利用率远远高于亚硒酸钠处理。综合紫甘薯含硒量和施硒量对生长的影响结果分析,施用硒酸钠和亚硒酸钠均能增加紫甘薯薯块的硒含量,紫甘薯对硒酸钠敏感性高于亚硒酸钠,生产过程中应充分考虑施用硒酸钠对作物造成的毒害。  相似文献   

13.
Selenium (Se) is a micronutrient in mammalian nutrition and is accumulated in kale (Brassica oleracea L. var. acephala), which has high levels of lutein and beta-carotene. Selenium, lutein, and beta-carotene have important human health benefits and possess strong antioxidant properties. The objectives of this study were to determine the influence of different Se [as sodium selenate (Na(2)SeO(4)) and sodium selenite (Na(2)SeO(3))] fertility levels on (1) biomass accumulation, (2) the accumulation patterns of carotenoid pigments, and (3) elemental accumulation in the leaves of kale. Winterbor kale was greenhouse-grown using nutrient solution culture with Se treatment concentrations of 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 mg Se/L as Na(2)SeO(4) and 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mg Se/L as Na(2)SeO(3). Increases in either selenate (SeO(4)(-)(2)) or selenite (SeO(3)(-)(2)) resulted in decreases in kale leaf tissue biomass. Neither of the Se treatments had an effect on the accumulation of lutein or beta-carotene in leaf tissues. Increasing SeO(4)(-)(2) significantly increased the accumulation of kale leaf Se; however, leaf tissue Se did not significantly change over the SeO(3)(-)(2) treatments. Increases in SeO(4)(-)(2) affected the leaf tissue concentrations of P, K, Ca, Mg, S, B, Cu, Mn, and Mo, whereas SeO(3)(-)(2) only affected B and S. Growing kale in the presence of SeO(4)(-)(2) would result in the accumulation of high levels of tissue Se without affecting carotenoid concentrations.  相似文献   

14.
Foliar applications of a fertilizer of selenite or selenate were carried out to determine the influence of selenium on the yield and quality of green tea leaves harvested in early spring. Numbers of sprouts and the yield were significantly increased by the application of selenium. The sweetness and aroma of green tea leaves were also significantly enhanced, and bitterness was significantly decreased by the application of selenium. However, no significant differences were found in sweetness, bitterness, and aroma between tea leaves fertilized with selenite and selenate. Se concentration was significantly increased by selenium fertilization, and tea enriched by sodium selenate had a significantly higher selenium content than did tea enriched by sodium selenite. Total amino acid and vitamin C contents were significantly enhanced by the application of selenium. Tea polyphenol contents were significantly decreased by fertilization with selenium. The marked difference of tea polyphenols was also found between applications of selenite and selenate.  相似文献   

15.
The aim of this work was to study selenium (Se) speciation in the potato ( Solanum tuberosum L.) cultivar Desiree, enriched in Se by foliar spraying with a water solution containing 10 mg of Se/L in the form of sodium selenate. Four combinations of treatments were used: well-watered plants with and without Se foliar spraying and drought-exposed plants with and without Se foliar spraying. Water-soluble Se compounds were extracted from potato tubers by water or enzymatic hydrolysis with the enzyme protease XIV, amylase, or a combination of protease XIV and amylase. Extraction was performed using incubation at a constant temperature and stirring (37 degrees C at 200 rpm) or by ultrasound-assisted extraction (300 W), using different extraction times. Separation of soluble Se species (SeCys2, SeMet, SeMeSeCys, selenite, and selenate) was achieved by ion-exchange chromatography, and detection was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that the concentration of selenate extracted was independent of the enzymatic extraction technique (approximately 98 ng/g for drought-exposed and 308 ng/g for well-watered potato tubers), whereas the extraction yield of SeMet changed with the protocol used (10-36%). Selenate and SeMet were the main soluble Se species (representing 51-68% of total Se) in potato tubers, regardless of the growth conditions.  相似文献   

16.
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   

17.
Abstract

The objective of this sand culture experiment was to determine how fertilization methods (i.e., fertigation rates of 0.5, 1, and 2?mg Se·pot?1, foliar rates of 5, 10, and 20?mg Se· L?1) and fertilizer type (i.e., selenate or selenite) affected wheat Se concentrations. The results showed that the fertigation and foliar treatments both increased wheat Se content. In the fertigation and foliar treatment total Se content of wheat was greatest in the selenate treatments. In the fertigation treatment, the Selenite had mainly accumulated in the roots, while the Selenate was majority transported to shoot. In the foliar treatment, we found that most of Se was transported to grain. In addition, the organic Se concentration was the most than other Se fractions. In conclusion, selenate was more effective than selenite in both the fertigated and the foliar application treatments. And the foliar application was better than fertigation.  相似文献   

18.
Selenium (Se) is an essential micronutrient for humans, animals, and certain lower plants, but at higher concentrations Se becomes toxic to organisms. The boundary between the Se beneficial effect and its toxicity is narrow and depends on its chemical form, applied concentration, and other environmentally regulating factors. Due to the potential risk of toxicity in higher concentration, the aim of this study was to estimate the impact of increased concentrations of different forms of Se on the response of the wheat–soil–earthworm system. Soil, earthworms, and wheat grains were exposed to the Se in form of selenite and selenate in concentrations of 0.01, 0.1, and 1 mg kg−1. As an indicator of oxidative stress in wheat, lipid peroxidation levels (LPO) and total H2O2 content were determined, while antioxidative response was determined by catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase (GR) activities. The biomarker responses in earthworms were determined by acetylcholinesterase (AChE), carboxylesterase (CES), and antioxidative enzymes (CAT and glutathione S‐transferase) activities. Selenite and selenate increased Se content in the wheat and earthworms, while selenate application was more efficient, indicating higher bioaccumulation of this Se form. Both Se forms did not cause significant changes in the LPO level and H2O2 content, while GPX activities were elevated in all treatments, suggesting that oxidative stress was not induced in wheat. In earthworms, Se significantly reduced activities of AChE and CAT at some concentrations, while CES activity was increased at all concentrations applied. This study showed significant impact of Se on measured biochemical responses in wheat and earthworms, indicating the disruption of homeostasis. Obtained results can serve as basis for further studies on Se effects and will help in including different aspects necessary for understanding of Se impact on different components of soil ecosystems.  相似文献   

19.

Purpose

Both selenium (Se) and sulfate could largely affect methylmercury (MeHg) dynamics and phytoavailability in soil-rice systems, while their combined effects are less understood. Here, we aimed at exploring the potential effects of sulfate on MeHg accumulation in rice in the presence of Se.

Materials and methods

Rice was cultivated in inorganic Hg-spiked soils amended with Se only (selenite/selenate, “Se treatments”) or Se and sulfate (“Se?+?Sulfate treatments”). Soil parameters (e.g., pH and redox potential (Eh)), MeHg concentrations in soils, as well as MeHg or Se accumulation in rice plants were quantified during the rice growth period.

Results and discussion

Soil MeHg concentrations were generally comparable between Se?+?Sulfate and Se treatments. However, MeHg uptake by rice plants in Se?+?Sulfate treatments was 9–31 % lower than those in Se treatments, possibly due to the increased soil pH and formation of iron sulfides, which may reduce MeHg phytoavailability under sulfate amendment. Furthermore, sulfate input enhanced Se accumulation in root (especially in the presence of selenate), which could be responsible for the increased MeHg distribution in root and thus lower MeHg distribution in grain. Consequently, the reduced plant uptake of MeHg together with the decreased MeHg distribution in grain resulted in decline of grain MeHg concentrations in Se?+?Sulfate treatments (8–31 % lower compared to Se treatments).

Conclusions

Our results suggest that sulfate input with Se could further reduce MeHg accumulation in rice, which improved mechanistic understanding of MeHg behaviors in soil-rice systems.
  相似文献   

20.
Lentil is a cool season food legume rich in protein and micronutrients. The objective of this study was to determine the effect of a low dosage of selenium (Se) on biological nitrogen (N) fixation, seed Se, and grain yield in lentils. The experiment was carried out at the Carrington Research and Extension Center, North Dakota, USA in 2012 and 2013. Six lentil genotypes were treated with three Se treatments. Application of selenate significantly increased percent Nderived from air (%Ndfa; 44%) compared to selenite (38%) and control (37%). In addition, selenate significantly increased lentil seed Se (1129 µg kg?1) compared to selenite (844 µg kg?1) and the control (542 µg kg?1). Both %Ndfa and grain yield increased with Se application. Selenate was the most effective form to increase %Ndfa. More research is required to determine the biochemical relationships between lentil yield and the Nfixation under Se deficient soils.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号