外源硒对芒果硒含量及果实营养品质的影响

探讨叶面喷施和土施外源硒对芒果叶片和果实硒含量、果实矿质元素含量及营养品质的影响，以期为富硒芒果的安全生产提供理论依据和技术支持。以“桂热 82号”芒果为试材，叶面喷施以亚硒酸钠为硒源，设置0.0、25.0、50.0、100.0、150.0和 200.0 mg/L 6个浓度水平，于生理落果结束后，每 15 d喷施一次，连喷 2次。土施设置亚硒酸钠处理和硒酸钠处理，施肥量为 10 g/株，于花期沟施。结果表明，芒果叶片和果实中的硒含量随着叶面喷硒浓度的增加而递增。叶面喷施 50 mg/L亚硒酸钠可显著提高果实 Vc含量，200 mg/L亚硒酸钠可显著提高果实K、可滴定酸含量，100～ 200 mg/L亚硒酸钠可显著降低果实Zn、Ca含量。土施相同量的亚硒酸钠和硒酸钠均可显著提高芒果叶片和果实硒含量。土施硒酸钠叶片和果实硒含量显著高于亚硒酸钠。土施 10 g/株亚硒酸钠显著降低果实 Ca、Mg含量，土施 10 g/株硒酸钠显著提高果实 K、Vc含量，降低果实 Ca含量。叶面喷硒和土壤施硒均可显著提高芒果叶片和果实硒含量，其中叶面喷硒提高幅度远大于土壤施硒提高幅度。土施硒酸钠比亚硒酸钠更容易被芒果吸收。富硒芒果生产上推荐叶面喷施 25.0～ 50.0 mg/L亚硒酸钠，或者土施 10 g/株硒酸钠。     

叶面过量施硒对玉米产量、硒和矿质营养元素含量的影响

为了明确过量施硒对作物生长的毒害效应,为合理施用硒肥提供依据,本研究在田间条件下探究了叶面过量施硒对糯玉米京科糯2000和普通玉米郑单958两个品种产量、硒含量和矿质营养元素含量的影响。结果表明,叶面喷硒量(亚硒酸钠)≤0.2 g·L^-1时,京科糯2000植株生物量和籽粒产量与对照(不喷硒)相比持平或略有增加,未表现出毒害效应;京科糯2000在叶面喷硒量≥0.5 g·L^-1时,郑单958在叶面喷硒量≥0.1 g·L^-1时,其植株生物量和籽粒产量均明显降低;随着叶面喷硒浓度的增加,两品种玉米籽粒硒含量均逐步增加,郑单958产量和籽粒硒含量的变化幅度高于京科糯2000。叶面喷硒可显著提高玉米籽粒锌和铁的吸收量,对铜、磷、镁和钙的吸收基本无影响,但抑制硼的吸收。总体来看,过量施硒抑制2个不同品种玉米生长,造成产量下降,但可提高籽粒硒、锌和铁的营养水平。本研究对玉米微量元素营养调控具有一定的借鉴指导意义。     

生姜硒营养特性研究

通过叶面喷硒研究了硒对生姜产量、各部位硒含量和累积分配及品质的影响,旨在探究生姜硒营养特性,为富硒生姜的生产提供依据。结果表明,外源施硒可显著提高生姜各部位硒含量,且对生姜的产量有显著影响。三叉期和膨大期喷施硒酸盐,生姜各部位硒含量分别是亚硒酸盐的5.5～8.2倍和2.8～4.1倍;喷施亚硒酸盐,姜皮硒含量均高于姜肉,喷施硒酸盐,姜肉硒含量高于姜皮。无论何时喷施何种硒源,硒在生姜中的有机转化率均可达到57%以上,膨大期喷硒,生姜有机硒比例高于三叉期。喷硒处理下,生姜Vc、还原糖和姜辣素含量均有提高,因此施硒对生姜品质有一定改善作用。     

不同供硒水平对水稻硒的吸收和累积特性研究

以"南粳9108"为材料,在巢湖流域研究田间条件下不同供硒水平(Se 0、20、40和60 g/hm~2)以及等量硒肥二次施用对水稻产量和硒吸收、累积、转运及分配的影响。结果表明:一次性施用不同浓度硒肥对水稻有增产作用,但是增产效果甚微;施用硒肥能够显著促进水稻茎、叶和穗的硒含量,但随着时间的推移,茎、叶和穗的含硒量均出现上升再下降趋势;稻谷、糙米及精米中的硒含量与硒肥施用量呈显著正相关,硒肥处理平均硒含量依次为0.279、0.150、0.055 mg/kg,分别较对照不施硒肥高309%、142%和333%;地上部硒累积量与施硒水平呈极显著的正相关,随着施硒量的增加,尽管硒的表观利用率是增加的,但硒转运系数和硒的收获指数显著下降。等量硒肥二次分施较一次性施用对产量有较为显著的促进作用,该处理下水稻产量较对照增加15%;等量硒肥二次施用增加了稻壳和米糠中的硒含量,精米中的硒没有增加;较一次施用,等量硒肥二次施用肥料表观利用率较高,硒肥的收获指数和转运系数显著下降,地上部累积更多的硒在稻草中。综上所述,外源硒的添加确实能增加大米硒含量,使其达到国家富硒大米硒含量标准范围;但结果同时显示水稻中的硒相当大的一部分累积在谷壳、谷糠及稻草中,可考虑充分利用。     

叶面喷施硅和硒对水稻砷积累及光合参数的影响

本文采用盆栽试验，研究了在砷污染土壤上，水稻叶面分别喷施硅溶液、硒溶液和硅硒混合溶液对籽粒砷含量相对较低的水稻品种旌1优华珍和C两优华占以及籽粒砷含量相对较高的水稻品种丰优香占砷积累和光合参数的影响。试验结果表明，3种叶面喷施处理相比较而言，以叶面单独喷施硅降低水稻籽粒砷含量效果最好，优于叶面单施硒和叶面喷施硅硒混合液处理。叶面单独喷施硅与对照相比，显著降低了籽粒砷含量相对较低的两个水稻品种的籽粒砷含量，但对籽粒砷含量相对较高的水稻品种则没有显著影响。籽粒砷含量相对较低的水稻品种更多比例的砷固定在茎中使其稻米砷积累量较低。3种叶面喷施处理与对照相比均提高了水稻光合参数(如光合速率、气孔导度、胞间CO₂浓度)，光合参数与水稻砷浓度呈负相关关系，叶面喷施硅或硒对水稻叶片光合参数的影响差异可能是造成籽粒砷含量差异的重要原因，不同水稻品种叶片光合参数对外源硅或硒的敏感度或响应度不同。总之，叶面喷施硅溶液对改善水稻光合参数的效果最好，是减少水稻籽粒砷含量一项经济有效的措施，在生产应用实践中，要注意作物品种间的差异。     

叶面喷硒对不同作物籽粒硒含量及产量的影响

分析了黑龙江省主栽作物(水稻、大豆、玉米和小麦)叶面喷硒的效果。结果表明:原始籽粒含硒量以大豆最高,玉米最低,顺序为大豆小麦水稻玉米;而施入等量的硒后,4种作物籽粒硒含量都有明显的提升,提升幅度与喷硒量呈正相关,其中以小麦和水稻增加最高,大豆次之,玉米最少,且硒含量均在安全补硒值的范围之内。叶面喷硒后作物增产效果不明显。确定了叶面喷硒的浓度范围为11.25~22.50 g·hm~(-2),即可使水稻、大豆、玉米和小麦籽粒中硒含量满足低硒区居民补硒的需要;施硒时期综合比较,水稻的最佳喷硒时期是在扬花后期,玉米的最佳喷硒时期是在抽雄期,大豆是在初花期,小麦是在孕穗期。腐植酸硒降低了高浓度硒对作物的毒害作用,在生产实际中更具有安全性。     

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。     

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。     

叶面喷硒对水稻籽粒硒富集及分布的影响

在大田试验条件下，研究了江苏省苏南地区水稻（龙晴4号、86优8和丙9652）叶面喷施和未喷施亚硒酸钠对水稻籽粒硒含量、硒的形态及对蛋白质结合态硒的影响。结果表明：叶面喷施亚硒酸钠10g hm^-2，可使该地区水稻籽粒硒含量达255．3—586．5μg kg^-1，是不喷硒的7．9-11．0倍。无论喷硒还是未喷硒，水稻籽粒硒主要以有机硒的形态存在，有机硒含量占总硒量的87．72％-90．98％，对产量没有显著差异。总体看来，叶面喷硒可以显著提高籽粒蛋白结合态硒含量，籽粒蛋白质结合的硒占有机硒的43．07％-51．65％，占总硒的38．04％-48．98％。叶面喷硒与对照相比，二个品种（龙晴4号与丙9652）籽粒的蛋白谱带基本一致，只是喷硒的水稻籽粒在14～20kDa之间增加了一些蛋白条带，这可能是由于喷硒增加了一些小分子蛋白质的合成。     

水稻品种间吸收和转运硒特性差异机制研究

采用溶液培养试验比较了富硒水稻与非富硒水稻对硒的吸收和运输特征,期望揭示富硒水稻秀水48和非富硒水稻丙9652籽粒硒累积差异部分生理机制。结果表明,两品种水稻根部对硒吸收的Km值差异不大,但富硒水稻秀水48的Vmax是非富硒水稻的1.57倍,两品种水稻根系对硒的共质体吸收皆受载体调控。硒吸收时间动力学试验证实秀水48茎中硒的浓度和含量在各个处理时间段均要高于丙9652,富硒水稻秀水48的木质部汁液中硒的浓度大约是非富硒水稻丙9652的2倍,在相等蒸腾速率的条件下,秀水48地上部硒含量显著高于丙9652,说明两品种水稻向地上部转运硒的能力差异显著,秀水48更易将根中的硒转运到地上部,高效的转运体系是富硒品种地上部硒含量高的关键所在。富硒水稻具备很强的向地上部转运硒的能力,部分原因在于其根部木质部对硒的装载能力较强。     

土壤施硒酸钠对盐碱地油用向日葵产量及营养品质的影响

通过大田试验研究了土施不同浓度硒对盐碱地油用向日葵产量及营养品质的影响，为当地盐碱地的综合开发利用及富硒功能农产品的生产提供参考依据。油葵籽仁中全氮含量采用凯氏定氮仪测定，其他矿质元素含量采用原子吸收分光光度计测定，籽仁脂肪酸含量采用气相色谱法测定。结果表明: 土施适宜浓度硒肥(300 g/ha)有利于提高油用向日葵产量，而过低(100～200 g/ha)或过高浓度硒肥(400 g/ha)均降低了油用向日葵产量；土施100～200 g/ha硒，提高了K、S、Fe、Zn、Mn、Cu、Se、油酸和亚油酸含量，降低籽仁Cr、Cd、Pb含量；土施硒300 g/ha左右有利于降低籽仁棕榈酸和硬脂酸含量。综合考虑油葵产量和各营养指标的变化情况，在盐碱地生产富硒油用向日葵的最适宜的土施硒的浓度为200～300 g/ha左右?     

Chemical forms and stability of selenium in soil

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.     

Selective determination and formation of elemental selenium in soils

A selective method for the determination of elemental selenium in soil was developed and was applied to the study of elemental selenium in soil. (1) Elemental selenium extracted with carbon disulfide from soil was selectively transformed into selenocyanate ion by reacting with potassium cyanide in carbon disulfide. The selenocyanate ion formed was recovered into an aqueous solution and the amount of selenium in the aqueous solution was determined. This method was specific to elemental selenium and did not interfere with the other selenium compounds and soil components. The method was also highly sensitive and enable to determine more than 0.1 μg kg^-1 of elemental selenium in soil. (2) The formation of elemental selenium was confirmed, when a soil was submerged and the redox potential of the soil decreased. The amount of elemental selenium formed was proportional to the selenite content of the soil, indicating that elemental selenium is transformed from selenite upon its reduction.     

Assessment of seafood processing wastes as alternative sources of Selenium in plant production

Abstract

In some parts of the world, the soil selenium (Se) content is too low to ensure the Se level recommended for human or animal consumption in the crops produced. In order to secure a desired concentration of Se in crops, Se has been applied as mineral fertilizer to agricultural fields. Since only a minor part of the inorganic Se applied is utilized by plants and small increases in Se concentrations in, e.g., drinking water, may be toxic, the method is somewhat controversial. As an alternative to Se-enriched mineral fertilizer, different seafood-processing wastes have been examined as a source for Se in crop production. Both in greenhouse pot experiments and field trials the Se in seafood waste was not plant-available during the first growing season. There was no significant difference between the Se concentration in wheat growing in soil without added Se and in soil receiving Se from seafood waste in amounts ranging from 0.9 to 9 g ha^?1. Neither was any residual effect of Se in seafood waste seen during a second year growth period. Thus, seafood-processing waste cannot be regarded as a potential source of Se in crop production. Possible mobilization of formerly applied Se, as seafood-processing waste or Se enriched mineral fertilizer due to changes in soil redox conditions were examined in a leaching experiment. The mobility of formerly applied Se was generally very low, but the results indicated that under permanently wet soil conditions leaching of Se may occur in plant dormant periods in soils with low organic matter content and high pH.     

桑肠杆菌菌株的富硒特性及其喷施对玉米籽粒的硒素强化

硒是人体必需微量元素之一,对新陈代谢过程有十分重要的促进作用,通过生物强化措施可以增加人体对硒素的补充。该研究利用从植物内生菌中筛选出的一株具有将无机硒转化成生物利用率更高的有机硒的菌株IX+2 2,测定其16S r RNA基因序列,鉴定该菌株为桑肠杆菌(Enterobacter mori)。该文研究不同的硒含量、加硒时间与不同培养收集时间对菌株IX+2 2硒素转化率的影响。结果表明,培养基中硒含量越高,菌株IX+2 2胞内有机硒含量越高,硒素转化率越高,但达到某一个峰值后又开始下降;在对数生长期加硒有利于菌株IX+2 2的生长和对无机硒的转化;菌株培养24 h时收集硒素转化效果最好,继续培养菌体生长减弱。同时针对菌株对玉米籽粒富硒的强化效应做了进一步验证。该菌株对玉米籽粒富硒的强化作用表明:同等亚硒酸钠用量条件下,亚硒酸钠喷施处理后玉米籽粒中硒含量达到228.58μg/kg,而富硒微生物菌剂处理后籽粒中硒含量达到378.89μg/kg,是前者的1.66倍,富硒IX+2 2菌剂的富硒效果优于喷施亚硒酸钠溶液。该研究结果可为玉米籽粒的硒素强化提供理论支撑。     

Biofortification of wheat cultivars with selenium

ABSTRACT

Biofortification experiments with three winter wheat cultivars treated with sodium selenate through foliar- and soil-fertilisation were conducted at two locations in Croatia and Serbia in two consecutive years to increase the selenium (Se) concentration in bread-making wheat grain. The treatments were: (a) 5?g?ha^?1 Se foliar-, (b) 10?g?ha^?1 Se foliar- and (c) 10?g?ha^?1 Se in soil surface-application and they were compared with (d) control. Both Se foliar- and soil-fertilisation increased the Se concentration in grains from 2.6- to 4.6-fold. The concentration in grain was highest with Se foliar-fertilisation of 10?g?ha^?1 and it was increased by 29–32?µg Se kg^?1 dry weight for each gram of Se applied per ha. The wheat cultivars differed in grain yield and Se uptake (g?ha^?1 Se). However, on average, there were no differences between wheat cultivars with respect to Se grain concentrations. Agronomic use efficiency (by grain) was significantly higher for Se foliar- (19%) than for soil-fertilisation (13%). It can be concluded that agronomic biofortification of winter wheat can be effective in increasing Se grain concentration, where the efficiency depends on the rate of Se applied, application method and local environmental conditions rather than on cultivar differences.     

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)。     

Selenium uptake response among selected wheat (Triticum aestivum) varieties and relationship with soil selenium fractions

Some South Dakota soils contain high levels of available selenium (Se) for crop uptake. A field study was conducted to determine if any popular wheat (Triticum aestivum) varieties demonstrate differential Se uptake. A total of 280 samples including eight winter wheat and ten spring wheat varieties were analyzed for grain Se concentration and uptake for two growing years. Soil samples were sequentially fractionated into (1) plant available (0.1?M KH₂PO₄ extractable) and (2) conditionally available (4?M HCl extractable) pools and analyzed separately for total Se. Selenium concentration in wheat grain had a wide variability and the mean value over two years was 0.63?µg?Se?g^?1. Grain Se concentration and Se uptake were not significantly different by wheat varieties tested in this study. Grain Se concentration was significantly correlated with soil Se levels, soil pH, and orthophosphate-P content within a location, but grain Se concentration was strongly influenced by geographical location in which different amounts of soil Se bioavailability occurred.     

马铃薯硒营养强化技术研究进展

硒是人体必需的微量元素,马铃薯是世界上第4大主粮作物,施用硒肥是生产富硒马铃薯的主要途径。本文介绍了马铃薯硒营养强化技术研究进展,阐述了硒在马铃薯植株内的一般累积分布规律,硒肥对马铃薯生长发育、产量和品质的影响;介绍了马铃薯生长过程中硒营养强化的生理遗传机制等内容;总结了近年来马铃薯富硒栽培技术和新型肥料研发情况;指出绿色环保、低廉高效的生物有机硒肥、缓释硒肥将是未来的发展方向。