叶面施硒对黑豆硒吸收转运特征及籽粒硒形态的影响

为了明确叶面喷施亚硒酸钠对黑豆硒吸收转运特征及籽粒硒形态的影响,采用小区试验在黑豆结荚兴盛期进行一次性叶面喷施亚硒酸钠(施硒量分别为0、6、12、18和24 mg·m^-2)处理,分析比较不同浓度亚硒酸钠处理下黑豆产量、各器官硒含量、籽粒有机硒转化率和品质性状的差异。结果表明,各施硒水平对黑豆各器官总硒含量均有提升作用,在24 mg·m^-2硒处理时各器官总硒含量最大,根、茎、荚和籽粒硒含量分别较对照提高了8.74、8.37、9.85和65.21倍,硒处理后各器官总硒含量呈现籽粒>根≈荚>茎的特点。籽粒中硒以有机硒形态存在,且有机硒转化率随着亚硒酸钠浓度的增加呈下降趋势,在0、6、12、18和24 mg·m^-2施硒处理时,有机硒含量分别为0.071 4、1.101 8、1.510 6、1.811 1和2.093 5 mg·kg^-1,有机硒转化率分别为94.52%、84.81%、70.30%、60.11%和52.43%。叶面喷施亚硒酸钠显著提高了黑豆籽粒蛋白质含量和分离蛋白硒含量,但对脂肪含量的影响较小,在24 mg·m^-2硒处理时蛋白质含量和分离蛋白硒含量分别较对照增加了2.4个百分点和117.35倍,分离蛋白硒含量占有机硒和总硒含量的比例分别为90.29%和47.39%。适宜浓度亚硒酸钠叶面喷施对黑豆产量具有促进作用,但浓度过高导致增产效果减弱。综上,叶面喷施亚硒酸钠可提高黑豆各器官总硒含量,但黑豆籽粒有机硒转化率随喷施浓度的增加呈下降趋势,且黑豆籽粒有机硒主要以蛋白质形式存在。本研究结果为应用外源硒强化技术生产富硒黑豆提供了科学依据。     

富硒蚯蚓的培养及其硒富集作用研究

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。     

叶面喷施硒肥对小麦籽粒及面粉硒含量的影响

为了探明叶面喷施硒肥对小麦籽粒及制粉各粉路硒含量的影响,本研究选用4个小麦品种,在拔节和抽穗期分2次喷施0.017%亚硒酸钠叶面肥,并对成熟期籽粒进行制粉,分析各粉路的总硒、无机硒和有机硒含量。结果表明,叶面喷硒对小麦籽粒和面粉的总硒、有机硒和无机硒含量的影响存在品种间差异。喷施硒肥后,4个小麦品种籽粒的总硒含量提高了26.4~35.8倍,但小麦籽粒产量无显著变化。皮磨粉、心磨粉、统粉、小麸和大麸5种粉路中,小麸的总硒含量最高,其次为大麸,皮磨粉、心磨粉和统粉的总硒含量较低。与硬质小麦相比,软质小麦出粉率低,面粉的总硒量损失较多。经制粉,对照和喷硒样本的总硒积累量分别损失52.97%~69.28%和36.73%~44.51%。对照样本中,各粉路的有机硒含量略高于无机硒含量;而喷硒处理样品中,除宁麦20的小麸外,各粉路的有机硒含量均略低于无机硒含量。本研究揭示了制粉粉路硒分布规律,这对于富硒小麦的加工利用具有重要的指导作用。     

Selenium Levels in Mainland Portugal

Selenium contents in the Portuguese (mainland) territory, resulting from a few environmental studies held since 1990 using lichens, vascular plants, soils and air particulate matter (APM), are presented and discussed herein. Values for Se in soils, epiphytic lichens and higher plants are within the typical ranges found in the literature. Compared to vascular plants, lichens display higher contents at the same locations. In what concerns Se in airborne particulates, all surveyed sites show values that are typical of urban areas. In two of such sites – Monchique and Carregado – Se concentrations in transplanted lichen thalli of the Parmelia genus (mostly, Parmelia sulcata Taylor) were compared to the results obtained from airborne matter, and a good correlation was found for the corresponding data-sets at either location. Other than the degree of association, it is especially noteworthy that the lichen transplants appear to accumulate much more Se at Monchique (a remote, rather clean site) than at Carregado (in the immediate vicinity of an oil-fired, power plant), even if its amount in the atmosphere is lower at the former location.     

Selenium accumulation in selected vegetables

Greenhouse experiments were conducted to determine selenium (Se) uptake by sulfur‐accumulating vegetables. Cabbage (Brassica oleracea var. capitata), broccoli (Brassica oleracea var. botrytis), Swiss chard (Beta vulgaris var. cicla) and collards (Brassica Oleracea var. acephda) were grown in a soil mix to which 4.5 mg of selenate or selenite had been added per kg of soil. Plants were grown to maturity, separated into plant organs, and the tissues analyzed for Se and sulfate (SO₄). Vegetables grown in selenate laden soil significantly (P<0.05) accumulated higher concentrations of Se than plants grown in selenite laden soil. The highest concentrations of Se and SO₄ were found in the broccoli floret and vegetable leaf tissues.

A second greenhouse experiment examined the uptake of Se and SO₄ in broccoli (Brassica oleracea var. botrytis) grown hydroponically with increasing Se concentrations. Treatments consisted of three Se concentrations (2, 6, and 15 mg of selenate, added as Na₂SeO₄/L to a synthetic water solution, including SO₄). Solution samples were taken weekly and analyzed for Se and SO₄. The removal or uptake of both Se and SO₄ by broccoli was positively related (P<0.05) with time at each Se concentration. After 6 weeks in Se treatments, uptake responses of Se and SO₄ were significantly different (P<0.05) based apon analyses of covariance. Composite leave samples were also taken from the broccoli plants and analyzed for Se and SO₄. Selenium concentrations were negatively correlated (P<0.08) with SO₄ concentrations in the leaf tissue.     

恩施野生川续断的硒含量与富硒特征

为了认识恩施野生川续断的硒含量及其富硒特征,在恩施地区8个不同硒含量地点采集了川续断植株及其生长地的土壤样品,运用氢化物发生原子荧光法测定了川续断根、茎、叶、花和土壤样品的硒含量,分析了野生川续断的富硒特征。结果表明:①供试川续断样品根、茎、叶、花和土壤样品的硒含量变化范围分别为0.029～94.87、0.008～39.45、0.040～123.14、0.026～143.94和0.6～277.3mg/kg,且不同部位的硒含量与土壤硒含量均呈极显著的线性相关;②供试川续断样品对硒的生物富集系数和转运系数分别为0.012～0.727和0.279～2.200,均以茎最低;③根据川续断对硒的转运系数可以将所采集的川续断样品分为叶富集型和花富集型,低硒土壤环境下,川续断为叶富集型,高硒土壤环境下,川续断为花富集型;④恩施野生川续断在高硒土壤环境中仍能正常生长,具有较强的富集土壤硒的能力,应属于聚硒植物。本结果对川续断在富硒环境下的培育和开发具有实际意义。     

磷、硒配施对冬小麦硒吸收及土壤硒形态转化的影响

为研究磷硒配施对冬小麦根土界面硒有效性及形态分级的影响,并探究磷硒配施提高土壤硒有效性的可能机制,以冬小麦为试验材料进行根箱培养试验,设置0(P0)、80(P80)、160 mg·kg^-1(P160)3个磷水平和0(Se0)、1 mg·kg^-1(Se1)2个硒水平,分析冬小麦植株磷硒含量、累积量、迁移系数及根际和非根际土5种硒形态含量。结果表明,无论施硒与否,随着磷含量的增加,冬小麦生物量、地上部和根系磷含量均增大。施硒1 mg·kg^-1显著降低了P80和P160水平下冬小麦生物量、P160水平下根系磷含量及各部位磷累积量。在Se1条件下,施磷增加了各部位硒累积量,但显著降低了地上部硒含量和硒从根系向地上部的迁移系数。在Se0条件下,P160处理增加了根际土壤和非根际土壤中的可交换态硒含量。在Se1条件下,P160处理根际土壤中可交换态硒含量显著高于非根际土壤,但铁锰氧化物结合态硒和残渣态硒含量低于非根际土壤。综上所述,适宜的磷硒配施可影响土壤中各种硒形态的转化过程,可能是由于磷的施入和根系活动共同作用促进了土壤中铁锰氧...     

硒的生物学研究进展

本文对硒的生物学研究的国内外动态、主要成就及其进展进行了综合性阐述。我国大多数地区处于低硒或缺硒状态，但在局部地区又发现拥有较丰富的硒资源，根据这一特点，从资源的合理开发和持续利用及生态环境效益的角度出发，进行了一些探讨性评价，并对未来研究趋向提出展望。     

外源硒肥对茶叶硒含量及化学品质的影响研究

硒肥对提高茶叶品质和增加茶树体内硒含量具有明显的促进作用。为了探讨硒对茶叶品质的影响机制,本研究进行了土施和喷施硒肥的盆栽试验。结果表明:叶面喷施和土施Na2SeO3两种施用方式对茶叶硒含量的提高及品质的改善都非常有利。叶面喷施浓度为120μgSe/ml时,喷施后第12天,春茶的硒含量最高为0.374μg/g;叶面喷施浓度为180μgSe/ml时,喷施后第18天,夏茶和秋茶的硒含量最高,分别为0.380μg/g和0.368μg/g。采用土施硒肥的方法制富硒茶时,土壤施硒量应不少于8mgSe/盆。叶面喷施浓度为180μgSe/ml时,夏茶化学品质提高最为明显,其中酚氨比下降为对照的65.73%,可溶性糖含量增加到对照的116.30%。与叶面喷施有降低儿茶素含量的作用相比,土施硒肥对整个采摘期内茶叶儿茶素的含量无明显影响,因此对改善茶叶品质特别是春茶品质的作用后者优于前者。     

硒肥对猕猴桃果实硒含量及其营养品质的影响

采用叶面喷施、根施及根叶并施方式对猕猴桃植株进行富硒处理。结果表明:3种施肥方式对于提高猕猴桃果实硒含量效果的顺序为叶面喷肥根叶并施根施,以叶面喷施0.5 kg硒肥最优,果实硒含量增加了103.5%;提高果实维生素C(Vc)含量的效果顺序为根施根叶并施叶面喷肥,根施0.5 kg硒肥最为显著,果实Vc含量增加了23.0%,而叶面喷肥后果实Vc含量下降;提高果实可溶性固形物含量的效果顺序为叶面喷肥根叶并施根施,以叶面喷施0.5 kg硒肥最优,果实可溶性固形物含量提高了37.2%。结合猕猴桃果实硒含量、营养品质、果树长势以及果园管理成本等因素,建议选用果树绽叶期根施硒肥0.5 kg·株-1作为富硒猕猴桃果园的施肥技术。     

不同用量腐植酸对土壤有效硒含量和硒的形态以及大蒜硒吸收的影响

采用室内土培和网室盆栽的方法,研究了不同用量的腐植酸对土壤有效硒含量和硒形态以及大蒜硒吸收规律的影响。结果表明:土壤有效硒含量随着腐植酸用量的提高而增加,20%OM处理的土壤有效硒含量(43.3~50.6μg·kg~(-1))10%OM(37.6~48.8μg·kg~(-1))5%OM(36.0~44.1μg·kg~(-1))CK(33.0~41.5μg·kg~(-1))。可溶态硒与土壤有机质含量的关联度最大(关联系数为0.821),其次为有机硫化物结合态硒(关联系数为0.693),铁锰氧化物结合态硒关联度最低(关联系数为0.482)。随着腐植酸用量的增加,土壤有机质含量得到相应提高,土壤中有机质的含量与可溶态硒、可交换态及碳酸盐结合态硒和有机硫化物结合态硒呈显著正相关,其相关系数分别为0.963、0.962和0.906,而与其他形态的硒相关性不明显。大蒜各部位干重的硒含量为根(0.167~0.653 mg·kg~(-1))茎(0.114~0.326 mg·kg~(-1))叶(0.056~0.086 mg·kg~(-1)),且4个处理大蒜鳞茎鲜重的硒含量为0.018~0.110 mg·kg~(-1),均达到了富硒食品标准(HB001/T—2013)。     

钼硒配施对小白菜钼硒形态及硒价态的影响

通过盆栽试验研究钼硒配施对水培小白菜钼硒形态及硒价态的影响。结果表明:施硒增加了小白菜地上部及地下部醇溶态和水溶态钼含量,降低了小白菜地上部及地下部盐溶态及醋酸溶态钼的含量,增加了地下部盐酸溶态钼含量,对地上部盐酸溶态钼含量没有太大的影响。施钼对小白菜地上部醇溶态、水溶态硒含量影响不大,增加了盐溶态及盐酸溶态硒的含量,降低了醋酸溶态硒的含量;施钼对小白菜地下部醇溶态硒含量影响不大,降低了水溶态硒的含量,增加了盐溶态、醋酸溶态及盐酸溶态硒的含量。施用四价的亚硒酸钠对小白菜可食部位硒的有机化较为有利,并且施钼也能促进高硒水平下小白菜体内硒的有机化。因此,钼硒配施虽然对小白菜体内钼和硒的各赋存形态有拮抗作用也有协同作用,但是有利于生产富含有机硒的作物。     

水稻硒营养研究进展

硒是人类和动物必需的微量营养元素。目前我国居民的膳食普遍存在硒摄入量不足的现象,因此提高粮食作物中硒的含量,研究水稻硒营养吸收对改善我国居民硒营养状况具有重要意义。在总结相关文献的基础上,概要介绍了稻田土壤硒的赋存形态、有效性及其影响因素,并从水稻体内硒的含量、吸收积累和代谢途径等方面总结水稻体内硒的吸收特性和代谢机制。施硒能促进水稻产量的增加,提升水稻的品质,并能够调节水稻的光合作用,增强其抗氧化能力和抗逆性,从而保护水稻的正常生长发育。虽然目前已有研究在水稻体内硒的吸收、转运及代谢机制等方面取得一定的进展,但有关富硒的调控机制、遗传机制以及硒与其他植物营养元素的互作协同机制同样也值得深入研究,为生产富硒水稻和植物硒资源的开发利用提供理论依据。     

Selenium species in selenium-enriched and drought-exposed potatoes

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.     

施硒对芦笋硒含量与品质的影响

以大棚种植的4年生绿芦笋"井冈701"为试材,研究不同浓度的亚硒酸钠溶液的不同施用方式对芦笋含硒量和营养品质的影响。结果表明,叶面喷施和土壤浇灌两种方式对芦笋体内硒的积累呈现不同的特点,但均能显著提高总硒含量,其浓度跟施硒浓度成正相。土壤浇灌100 mg kg~(-1)亚硒酸钠溶液可使芦笋嫩茎总硒含量在2个月以上的时期内持续稳定在100μg kg~(-1)的安全范围内,效果最好。而有机硒含量随施硒浓度的增加先升高后下降。施用适当浓度的亚硒酸钠能提高芦笋嫩茎的Vc和总蛋白质含量,改善芦笋的营养品质。     

水稻对外源硒的吸收利用研究

硒是人体必需的微量营养元素,食物是人体硒的主要来源,外源硒调控是生产富硒农产品的重要手段之一。通过盆栽试验,研究外源硒添加条件下水稻对硒的吸收利用问题。结果表明,土壤添加外源硒为0.2~0.6 mg Se·kg~(-1)土的条件下,对水稻的生长性状没有显著影响,但能显著增加水稻各部位的全硒含量。硒在水稻体内各部位的含量大小关系为:稻根茎叶糙米精米谷壳;但在各主要部位的总累积大小为:茎叶糙米精米稻根谷壳。在自然土壤上硒相对更多地富集于水稻根系,而外源添加四价硒处理,水稻吸收的硒相对更容易转移至地上部位,甚至更容易在糙米和精米中富集。水稻植株对外源硒的吸收利用率为2.87%~3.75%,地上部和籽粒累积外源硒的量占添加外源硒总量分别为2.60%~3.45%和0.94%~1.32%。     

Selenium Content and Uptake in Crops as Affected by Soil Selenium Content and Implications on Human Health

The selenium contents of soil and its uptake by a wide variety of crops are analyzed along a transect, with the sampling stations located at Mawkyrwat, Upper Shillong, Pynthormukrah, and Nongpoh. Each site is successively farther away from uranium deposits, with the closest being Mawkyrwat (50 km). Leafy vegetables had greater selenium content than tubers and fruits. The concentrations of selenium in soil ranged from 70 μg g^?1 to 296 μg g^?1 and in vegetables varied from 26 μg g^?1 to 225 μg g^?1. Selenium is known to be a decay product of uranium, and the results indicate that the selenium content of soil and vegetables of Mawkrywat is greater than the other three sampling sites. This can be attributed to the proximity of this site to uranium deposits of Domiasat. The possible implications of selenium on human health are discussed.     

Selenium Concentration in Spring Wheat and Leaching Water as Influenced by Application Times of Selenium and Nitrogen

ABSTRACT

Selenium (Se) deficiency in Scandinavian soils is a common problem, and crops generally contain inadequate amounts to meet human need. This study shows a relationship of the Se concentration in spring wheat (Triticum aestivum L., c.v. ‘Helena’) and leaching water with timing of nitrogen (N) [as ammonium nitrate (NH₄NO₃)] and Se [as sodium selenate (Na₂SeO₄)] application. Ammonium-nitrate was applied by two methods (i) whole amount at sowing and (ii) in split application as 75% at sowing and 25% at stem elongation. Selenate was applied at cereal growth stages after sowing, e.g., tillering, stem elongation, head emergence, and milking. Split N application in comparison to one N application increased the grain protein content from 12.1 to 13.7 mg g^{? 1}, and grain Se was increased from 0.8 to 1.1 mg kg^{? 1} when Se was applied at stem elongation and from 0.6 to 0.9 mg kg^{? 1} when applied at heading. The highest Se concentration in plant was achieved with the split N application and Se application at stem elongation or heading. Selenium leaching losses increased with increasing selenium concentration in the wheat grains. No differences in Se leaching losses were obtained with split N application. Applying selenate and ammonium-nitrate together after tillering increased the grain Se concentration, but did not affect the potential leaching of Se, and thus could be considered as an appropriate time of application of these elements.     

恩施典型富硒区土壤硒与其他元素组合特征及来源分析

硒是重要的人体和动物必需微量元素之一,在功能农业发展中起着重要的作用。为了研究高硒土壤中硒与其他元素组合特征及来源,从而支撑富硒资源的安全有效利用,本研究在恩施市沙地乡系统采集并分析了200个表层土壤样和2组土壤垂向剖面样品,运用统计学工具进行了聚类分析和因子分析。结果表明:研究区表层土壤硒含量平均值为1.88 mg/kg±2.51 mg/kg,明显高于全国表层土壤硒含量平均值。研究区土壤元素组合特征可分为三类,第一类中硒与钼、钒、铬、镉和镍等元素具有较强的伴生关系,与黑色岩系分布密切相关;第二类为三氧化二铝、铅和砷等元素/氧化物,与土壤中黏土矿物有关;第三类为钙和锶等元素,表明该同族元素的地球化学性质具有相似性。因子分析结果进一步证实了土壤硒和镉伴生主要发生在黑色岩系,不同成土母质硒等元素差异较大。     

内源调控与外源补硒对红壤中硒有效性及水稻产量的影响

通田间试验,比较了富硒红壤增施钙镁磷肥或喷施作物生长促进剂的内源调控处理与施用硒肥或喷施硒素的外源补硒处理对土壤中硒的化学有效性、水稻生长的影响以及水稻吸收硒的效果。结果表明,内源调控处理与外源补硒处理均提高了土壤中硒的化学有效性,促进了水稻生长,且都使得水稻籽粒的硒含量达到江西省富硒大米地方标准(70~300μg kg~(-1)),其中,增施钙镁磷肥并配施氨基酸叶面肥的内源调控处理使稻米中硒含量达到了0.081±0.004 mg kg~(-1),增幅达到极显著水平(P0.01),与外源补硒的效果接近。因此,在富硒地区通过土壤内源调控措施能充分利用土壤硒素资源,生产富硒农产品,具有较好的应用前景。