土壤硒对油菜含硒量、生长和产量的影响

应用上培盆栽试验,研究了土壤不同硒水平对油菜生长和产量的影响以及油菜不同时期各器官含硒量。结果表明:(1)土壤加硒至15—20ppm时,油菜出现中毒。(2)随土壤硒含量增加,油菜各器官硒含量成倍增加,表明油菜富硒特点明显。(3)油菜籽中硒主要分配到菜籽饼内,菜籽油的硒含量相对较少。     

西宁部分奶牛场奶牛乳硒含量的检测及评价

采用荧光法对西宁地区三个奶牛场的29头(A,B,C 场分别为10,11,8头)奶牛的乳样进行硒含量分析。检查结果表明:A,B,C 三场平均乳硒含量分别为19.93ng/ml,21.01ng/ml,13.40ng/ml,B 场和 C 场间存在着极显著差异(P<0.01);58.62%的被检牛乳硒在20ng/ml 以下,17.24%的被检牛乳硒在10ng/ml 以下。初步证实西宁地区存在着奶牛缺硒的状况。     

浙江富阳金属冶炼厂周围水田土壤-水稻系统中As、Se含量特征

本文研究了浙江富阳金属冶炼厂周围水田土壤-水稻系统中As、Se含量特征。所采土壤样品中,As含量高于土壤环境质量一、二和三级标准的分别占总数的21.15%、9.62%和7.69%。该金属冶炼厂周围88.46%的土壤属于富Se土壤。足Se土壤占总样的5.77%,过量Se土壤占3.85%,高Se土壤占5.77%。水田土壤可能受与金属冶炼有关的点源污染影响。糙米的As、Se含量高于全国糙米As、Se背景值,可食部分As、Se浓度均未超过我国规定的水稻卫生标准。     

烤烟硒积累及其与土壤和气候关系

在我国南北主产烟区的7省11县采用统一栽培模式,研究了烤烟Se含量及其与环境的关系。结果表明,在烤烟各器官中,含Se量为根系>叶片≈烟杈(烟花)>茎;烟叶Se含量为下部叶<中部叶<上部叶。在烟株生长发育过程中,叶片含硒量差异不大,累积量成“S”形曲线增加,积累速率呈单峰曲线变化;就地域而言,南方烟叶的Se含量与北方基本一致。此外,烟叶Se含量的变异系数较大,说明环境条件影响烟叶中的Se含量。在气象因素中,烟叶Se含量与日均气温、日均10.cm地温呈显著正相关,与降雨量(或相对湿度)呈显著负相关。在土壤因素中,烟叶Se含量与pH、土壤含Se量呈正相关,与土壤速效磷、有机质呈负相关。     

贵州普安县优质富硒茶及土壤环境调查

为促进普安县优质茶产业发展,对该县优质茶叶及产地土壤环境进行了调查。结果表明:贵州普安县精细加工的春茶品质优良,普安茶场的春茶中硒元素含量为0.28～0.33mg/kg,达国家富硒茶标准;该茶场分布于二叠系上统龙潭组(P3l)地层之上,茶园土壤硒含量达0.59～3.07mg/kg,属富硒～高硒土壤。该县在类似地质环境与土壤条件的地区发展优质富硒茶叶生产,具有很大的潜力。     

外源硒对镉胁迫下芥菜种子萌发生理效应的影响

采用水培的方法,以芥菜为材料,研究了施加不同质量浓度外源硒（Se）（1,2,6,8 mg/L）对单一质量浓度镉（Cd）（10 mg/L）胁迫下芥菜种子萌发生理效应的影响。结果表明,单一质量浓度Cd胁迫显著抑制了芥菜种子的发芽（P＜0．01）,种子萌发过程中幼苗中的可溶性糖含量和淀粉含量显著低于对照（P＜0．01）,丙二醛（MDA）含量则明显高于对照（ P＜0．01）,表明单一Cd对芥菜种子的萌发产生了一定程度的伤害;单一Cd胁迫下加入不同质量浓度外源Se后,能够有效地提高种子的发芽率,使可溶性糖和淀粉含量增加,MDA含量明显降低,表明外源Se可以有效地缓解Cd对芥菜种子萌发造成的伤害;当外源Se质量浓度为2 mg/L时,芥菜的发芽率、可溶性糖含量和淀粉含量为最大值,且与对照相比变化不大（P＞0．05）,但均显著高于单一Cd胁迫下的相应值（P＜0．01）,MDA含量最低,且显著低于对照和单一Cd胁迫下的相应值（P＜0．01）,表明当外源Se的质量浓度为2 mg/L时,对单一质量浓度Cd胁迫下芥菜种子萌发的缓解作用最佳。     

硒处理对泰山四叶参矿质元素及氨基酸含量的影响

采用盆栽试验研究硒处理对泰山四叶参矿质元素及氨基酸含量的影响,以期提高泰山四叶参营养品质。结果表明,硒处理降低泰山四叶参根干物质积累,硒处理浓度越高,干物质积累量越低。不同施硒处理后,泰山四叶参Mg含量明显提高,降低Ca、Fe、Mn含量,Zn、Se含量随施硒浓度的增大呈降一升一降的变化趋势且均于1．0mg／kg＋t处理时达到最大值。硒处理改善泰山四叶参所含人体必需氨基酸的含量,丙氨酸、异亮氨酸明显增加,以1．0mg／kg＋处理含量最高。1．0mg／kg十±处理有利于提高泰山四叶参保健价值。     

Status of selenium and vitamin E on Norwegian organic sheep and dairy cattle farms

Herbage selenium (Se) concentration is generally low in Norway. It is unknown whether feeding practices on Norwegian organic farms fulfil the dietary needs of Se and vitamin E for sheep and dairy cattle. Therefore we analysed Se in soil and herbage, and Se and vitamin E in animal blood in the indoor feeding season at 14 organic dairy and 14 organic sheep farms. The herbage Se concentration was low. Approximately 50 and 35% of all samples in the first and second cut, respectively, had Se concentrations below the detection limit of 0.01 mg/kg dry matter (DM). The median (10th, 90th percentile) Se concentrations were <0.01 (<0.01, 0.03) and 0.02 (<0.01, 0.06) mg/kg DM in the first and second cuts, respectively. Whole blood Se concentrations were 0.10 (0.04, 0.15) μg/g in dairy cattle and 0.14 (0.03, 0.26) μg/g in sheep. Vitamin E concentrations were 4.2 (2.7, 8.4) mg/l in dairy cattle and 1.3 (0.9, 2.4) mg/l in sheep. None of the soil or plant variables explained the variation in herbage Se concentration, although Se in soil and plant tended to be correlated. Herbage Se concentration was inadequate to meet the dietary Se requirements. Vitamin E requirement was only met in dairy herds. We recommend Se and vitamin E supplementation to ruminants on organic farms.     

Uptake and remobilization of selenium in Brassica napus L. plants supplied with selenate or selenium‐enriched plant residues

Selenium (Se) biofortification via crops is one of the best strategies to elevate the daily Se intake in areas where soil Se levels are low. However, Se fertilizer recovery (SeFR) is low and most of the Se taken up accumulates in non‐harvested plant parts and returns to the soil with plant residues. A pot experiment with soil was undertaken to study the efficiency of inorganic Se (Na₂SeO₄) and Se‐enriched plant residues for biofortification, as well as to identify the bottlenecks in Se utilization by Brassica napus L. The soil was fertilized with Na₂SeO₄ (0 and 7 µg Se kg^?1) or with Se in stem or leaf residues (0 and 7 µg Se kg^?1). A treatment with autoclaved soil was included (0 and 7 µg kg^?1 as Na₂SeO₄) to unravel the impact of microbial activity on Se uptake. The Se‐enriched plant residues produced a lower Se uptake efficiency (SeUPE) and SeFR than did inorganic Se, and soil autoclaving enhanced Se accumulation in the plants. The time required for decomposition seems to preclude crop residues as an alternative source of Se. Furthermore, B. napus had a limited capacity to accumulate Se in seeds. The study shows that the bottlenecks in Se biofortification appear to be its low bioavailability in soil and poor loading from the silique walls to seeds. Thus, improved Se translocation to seeds would be a useful breeding goal in B. napus to increase SeFR.     

叶面施硒浓度和喷施次数对春玉米产量和硒含量的影响

旨在研究叶面喷施不同浓度氨基酸螯合有机硒肥和喷施次数对春玉米产量和各器官硒含量的影响。以玉米品种‘安科126’为试验材料,于2020和2021年在陕西省安康市汉滨区试验基地布置大田试验。试验采用裂区设计,以0、10、30和50 mg/L(以Se计)4个施硒浓度为主处理,以喷施1次、2次和3次为副处理。结果表明：与对照相比,2020年叶面喷施硒肥使玉米产量下降1.20%～16.95%。2021年除处理Se50-3和Se50-1产量分别较对照显著增加35.63%和32.54%以外,2 a试验结果其他施硒处理玉米产量与对照差异均不显著(P>0.05)。施硒浓度和喷施次数对玉米根、叶和籽粒硒含量的影响显著。玉米各部位硒含量随着喷施次数的增加而增加。除2020年茎以外,玉米根、茎、叶和籽粒硒含量在施硒浓度50 mg/L喷施3次下均达到最大值。2020年玉米根、叶和籽粒硒含量最大值分别为0.65、6.66和0.56 mg/kg,分别是对照的3.42、19.59、3.50倍;2021年玉米根、茎、叶和籽粒硒含量最大值为0.86、1.64、27.23和0.83 mg/kg,分别是对照的2.46、...