不同时期和方式施用氨基酸硒肥对梨树的影响

摘要：以16年生‘华酥’梨为试材，分别于盛花期和果实发育期，采用叶面喷施和土施两种方式施用氨基酸硒肥，结果表明：氨基酸硒肥可以改善梨果实品质，如极显著提高果肉中硒元素的含量（能够达到对照的8.8～16.3倍）、降低石细胞的含量（比对照降低39.9%～50.2%），喷施氨基酸硒肥还可以改善叶片质量。综合考虑施肥效果和硒的利用率，盛花期喷施氨基酸硒肥是最经济有效的方法。     

氨基酸硒叶面肥在苹果上的吸收运转及积累特性的研究

本研究以25年生富士苹果为试材，对氨基酸硒叶面肥在苹果上的吸收运转及积累特性进行研究。结果表明，叶面喷施氨基酸硒苹果对硒元素的吸收高峰期是花后30天到果实采收，而土施氨基酸硒处理苹果对硒元素的吸收高峰期是花后45天到果实采收；喷施和土施氨基酸硒肥后，硒在苹果果实各个部位中的积累和分布发生了变化，喷施处理果皮中的硒元素含量积累较多，其次是种子和果肉；土施处理硒在苹果果实中的积累是从内到外的，首先积累到种子，然后是果肉，最后积累到果皮；在氨基酸硒硒肥施用时，叶面喷施的硒元素利用率远高于土壤施用的硒元素利用率。     

设施桃对硒的吸收运转及积累特性的初步研究

本试验以设施栽培的4年生春雪毛桃（砧木为青州冬雪蜜桃）为试材，研究硒元素在桃中的吸收运转及积累特性，为设施桃富硒果品生产技术的提出提供理论依据。结果表明：从花后40d至80d，设施桃不同部位硒元素含量的变化趋势不同，其中叶片呈‘升-降-升（土施氨基酸硒）’与‘持续上升（叶面喷施氨基酸硒）’、果肉呈‘升-降’、果皮呈‘升-降（土施氨基酸硒）’和‘降-升-降（叶面喷施氨基酸硒）’、果核呈下降的变化趋势；设施桃从果实硬核至转色阶段是设施桃可食部分-果肉对硒元素吸收的活跃期；硒肥的施用方式不仅影响硒元素在果皮、果肉和果核及果肉和叶片等各部位的累积顺序，而且显著影响硒元素的利用效率，叶面喷硒的硒元素利用率远高于土壤根际施硒的硒元素利用率。综上，设施桃从坐果到果实成熟，采用叶面喷硒，尤其是加强果实硬核至果实转色阶段的施用，是设施桃富硒果品生产的关键措施。此外，抑制设施桃果实成熟前后新梢的补偿性生长是减轻或避免果实中硒元素外流的重要措施。     

不同硒肥喷施时期对芒果硒含量及品质的影响

旨在通过大田试验，探讨广西“台农一号”芒果在不同生长时期叶面喷施硒肥后芒果品质的变化及果实硒的迁移转化规律，探索硒肥溶液的最佳叶面喷施时期，为广西富硒芒果生产提供参考。根据试验地芒果生长状况，划分3个硒肥溶液喷施时期，分别为花期（FL）、幼果期（YF）和膨果期（FE）。设低浓度（F0.1：0.1%硒肥溶液）、中浓度（F0.2：0.2%硒肥溶液）和高浓度（F0.4：0.4%硒肥溶液）3个硒肥喷施浓度水平，以不喷施硒肥作为对照（CK），共10个处理，每个处理设3次重复，共30株芒果树。分阶段采集叶片及果实样本，测定硒含量，并待芒果成熟后测定芒果可溶性固形物、Vc、可溶性糖和总酸度。结果显示：（1）叶面喷施硒肥溶液后，有机硒为芒果果实中硒主要存在形态，约占芒果果实总硒的95%。（2）叶面喷施硒肥溶液后芒果果实与叶片中硒含量显著上升，喷施浓度越高，含量越高，芒果不同部位在喷施硒肥溶液后硒含量表现为叶片>果皮>果肉。（3）随喷施后时间推移，在芒果花期和幼果期喷施硒肥溶液的处理果实硒含量下降，在膨果期喷施的处理果实硒含量则无显著变化。收获期时不同时期处理果实硒含量表现为膨果期>花期=幼果期。（4）不同时期下叶面喷施硒肥均有改善芒果果实品质、提升风味口感的效果。结果证明，在芒果膨果期喷施叶面硒肥更有利于芒果果实中硒积累，基于不同处理芒果硒含量和品质指标综合评价结果得到，在芒果膨果期叶面喷施0.4%硒肥溶液是生产富硒芒果的较优硒肥施用方式。     

叶面喷硒利于巨峰葡萄对硒的吸收运转

正据《中国土壤与肥料》2016年第4期《巨峰葡萄对硒元素的吸收运转规律》(作者郑晓翠等)报道,以4年生露地栽培巨峰葡萄(砧木为贝达)为试材,采用土施氨基酸硒肥0.1、0.2、0.3、0.4 g/株四种施用量和叶面喷施浓度分别为0.006%、0.01%、0.015%、0.02%的氨基酸硒肥2种处理方式,研究氨基酸硒的不同施用方法和不同施用量条件下巨峰葡萄对硒的吸收、分布和积累特性。试验结果显示,(1)盛花期叶面喷施0.01%氨基酸硒(最适浓度)和土施0.3 g/     

喷施氨基酸硒叶面肥对梨的果实硒含量及品质的影响

以秋白梨和花盖梨为试材，研究了喷施氨基酸硒叶面肥对梨硒含量及果实品质的影响，以期为富硒梨的生产提供理论依据。结果表明，喷施氨基酸硒叶面肥600倍液极显著提高了秋白梨和花盖梨的果实硒含量，花盖梨的果实硒含量显著高于秋白梨。喷施氨基酸硒叶面肥600倍液显著提高了秋白梨和花盖梨的单果重及果实纵横径，增大了果个；显著提高了果实的总糖含量、维生素C含量，降低了可滴定酸含量和石细胞含量，改善了果实品质；显著降低了秋白梨和花盖梨的果皮强度、果皮斜率脆性、果皮韧性和果肉平均硬度，显著降低了秋白梨的果皮破裂距离，提高了果肉细度，增加了秋白梨和花盖梨的成熟度及可食性。     

叶面喷施硒肥对紫花苜蓿富硒降镉效果的影响

为了缓解紫花苜蓿的镉累积并实现富硒目的，探究了不同浓度镉胁迫下叶面喷施硒肥对紫花苜蓿生长特征及富硒降镉特性的影响。以草原三号和中苜一号紫花苜蓿为材料，采用叶面喷施硒肥的方式，在初花期测量紫花苜蓿的株高、生物量并检测根茎叶部位的总硒、硒代蛋氨酸(SeMet)、镉等含量，分析叶面喷施硒肥对紫花苜蓿富硒降镉效果的影响。结果表明，施加外源硒对紫花苜蓿的生长和富硒量均有促进作用，表现为两个品种紫花苜蓿的株高、生物量、总硒和SeMet含量均显著提高，镉含量、镉富集系数、镉转运系数均显著下降。相同喷施硒肥浓度下，低浓度镉污染促进紫花苜蓿的生长，高浓度镉污染则抑制紫花苜蓿的生长。镉浓度为1 mg·kg^-1、施硒量为100 mg·kg^-1时，紫花苜蓿中硒含量最高、镉含量最低，各组织中总硒、SeMet含量：叶>茎>根，镉含量：茎<叶<根。相同条件下，中苜一号的生物量、总硒、SeMet含量均高于草原三号，镉含量低于草原三号，且在镉浓度为1 mg·kg^-1、施硒量为50 mg·kg^-1的条件下富硒降...     

不同硒肥类型对凌丰葡萄含硒量及品质的影响

硒(Se)是人类必需的微量元素之一,具有抗癌、预防衰老和增强免疫等多种生理机能。为选择适宜广西区域富硒果蔬产业的富硒叶面肥,以毛葡萄改良品种“凌丰”两性花毛葡萄为试验材料,采用“聚福硒”、“泰山草肥”、“中农6号”、“康熙宝”4种硒肥作为外源硒进行富硒葡萄试验研究。结果表明 ：1）施加硒肥葡萄果实含硒量较对照提高了1.2～16.8倍,“聚福”、“中农”富硒效果较好,果实硒含量可达75.85μg/kg和45.79μg/kg;2）喷施硒肥可提高葡萄部分品质,叶面喷施“聚福”后可显著提高葡萄总糖含量的同时降低总酸含量,喷施“中农”则显著提高了果实维生素C含量;3）随着采摘期延迟,“凌丰”毛葡萄果实硒含量、总糖含量、总酸含量均降低,而“中农”总糖含量略有增加且总酸降幅较大。综上,建议若计划于采收适期采收,可采用“聚福硒”作为富硒葡萄外源肥料;若延长采摘期可选用“中农6号”作硒肥。     

有机肥对苜蓿产量及红壤肥力的影响

在亚热带红壤地区研究有机肥（Ⅰ基肥、Ⅱ基肥＋石灰、Ⅲ基肥＋猪粪、Ⅳ不施肥）对苜蓿产量及红壤肥力变化的影响。结果表明，在相同的管理条件下，施用有机肥普遍提高苜蓿鲜草产量（P〈0．01）。处理Ⅱ增产效果最好，比不施肥处理可提高苜蓿鲜草产量14．52％（P〈0．05）。施有机肥可增加土壤pH值、有机质、全氮、全磷、速效氮、速效磷及速效钾的含量（P〈0．05），但全钾含量则减少，其中第Ⅲ组提高土壤全量养分和速效养分含量显著高于Ⅰ、Ⅱ组，第Ⅱ组对速效养分的增加高于第1组：     

不同施肥处理对果桑光合与果实品质及土壤微生物数量的影响

研究常规施肥(单施化肥)、减量施肥(有机肥代替减量化肥)、优化施肥(减量施肥基础上氮肥减量,增施有机肥和中微量元素肥料)3种施肥方式对桑树叶片净光合速率(P_n)、果实品质及土壤微生物数量的影响,为探求果桑高效施肥技术提供理论参考。结果发现,优化施肥桑树叶片P_n、叶绿素相对含量(SPAD值)、可溶性糖含量、蔗糖合成酶活性、中性转化酶活性、土壤细菌及放线菌数量等均高于减量施肥和常规施肥处理(P<005),而可溶性酸含量和可溶性酸性转化酶活性优化施肥处理显著低于常规施肥和减量施肥处理(P<005)。研究结果表明,优化施肥处理通过施肥方式的改变,增施有机肥,适量补施镁肥、硼肥、锌肥、硅肥等,可减少化肥的施用量,改善土壤理化性质,有助于提高果桑叶片光合作用及果实品质。     

Brain selenium accumulation in rat pups of selenium supplemented mothers

Selenium is essential for normal mammalian development. Being a component of antioxidant enzyme, glutathione peroxidase, it plays a major role in protecting the cells from free radical damage. The level of glutathione peroxidase was directly related to the amount of selenium present in various tissues and organs. A decrease in selenium leads to various pathological changes in humans as well as in various laboratory animals. The aim of the present study was to understand whether there is an increase in the level of selenium in different brain regions of rat pups whose mothers were supplemented with selenium, either 2 or 4 mg/l of their drinking water throughout the period of their pregnancy. There was a significant increase in the level of selenium in the cerebellum, cortex and hypothalamic and hippocampal tissues of selenium supplemented mothers as compared with those of non-supplemented mothers. The brain stem of these animals did not show any significant difference in the level of selenium. Furthermore, the differences in the level of selenium between the rat pups of 2 mg/l selenium supplemented mothers and 4 mg/l selenium supplemented mothers were not statistically significant. These studies suggest that supplementation of selenium to mothers during the period of their pregnancy can selectively increase the level of this trace element in different brain regions. Further studies are necessary to understand the significance of selective accumulation of selenium in specific brain regions on brain development and function.     

聚焦硒元素第三部分发展趋势

2000年重新修订的欧盟食品与饲料法正促使食物生产链发生重要的变化,该法律要求生产商提高产品质量,同时要求他们能够证明所生产产品的安全性和功效,否则必须退出欧盟市场。一个利用特殊酵母菌株生产的硒酵母产品成为欧盟新食品与饲料法颁布后首个获准生产的饲料添加剂之一,由此反映了社会对资源和创新的需求。     

Effect of subcutaneous selenium injection and supplementary selenium source on blood selenium and glutathione peroxidase in feedlot heifers

This study measured the effect on glutathione peroxidase (GSH-Px) and selenium (Se) in whole blood and plasma associated with subcutaneous Se injections in beef heifers fed organic or inorganic Se. Heifers (n = 120) were randomly divided into 2 groups, 1 of which received subcutaneous Se injections. Both groups were given the same total mixed ration with 3 mg of organic or inorganic Se daily. Until week 2, heifers that had received Se injections showed higher concentrations of plasma Se and GSH-Px and whole blood Se (P < 0.001) than those having had no injections. Concentrations of plasma Se and GSH-Px were higher in the group receiving organic Se than the group receiving inorganic Se. Whole blood GSH-Px concentrations increased significantly (P < 0.001) throughout a 12-week period but were not affected by Se source. Combination of Se injections and supplementation could help maintain normal Se and GSH-Px blood status in beef heifers during the first few weeks in the feedlot.     

利用产朊假丝酵母转化无机硒为有机硒的研究

对富硒酵母进行筛选并对发酵条件进行优化,得到富硒酵母的最适发酵条件:麦芽汁12°Be、培养基加Se量15mg/l、250ml三角瓶装量40ml、初始pH值为6.0、发酵时间40h、温度26℃、转速250r/min,经此培养所得的富硒酵母中的Se含量达到了1451.31μg/g。     

Effect of inorganic selenium supplementation on selenium retention in postweaning swine

A total of 64 weanling pigs was used in a randomized complete-block experiment to evaluate the efficacy of various inorganic Se levels on weekly Se balance measurements over a 5-wk post-weaning period. Four-week-old weaned pigs were fed a 20% protein, corn-soybean meal diet supplemented with 0, .3, .5 or 1.0 ppm Se from sodium selenite. Eight pigs were allotted by weight, litter and sex to each metabolism crate. A 2-d preliminary period followed by a 5-d collection period was conducted for five weekly periods. Feed intake was provided ad libitum but was similar between dietary Se levels. Fecal Se excretion increased each week and with increasing dietary Se level. Apparent digestibility of Se was relatively constant for each period when inorganic Se was fed, averaging approximately 70%, whereas it ranged between 30 to 40% for pigs fed the basal diet during wk 2 through 5. Urinary Se decreased during the postweaning periods for pigs fed the basal diet, but increased linearly as dietary Se increased during the initial 2-wk postweaning period and then quadratically during wk 3 through 5. There was a net loss of Se from the body when the Se-unsupplemented basal diet was fed during the initial 2 wk postweaning, whereupon, it became positive. Selenium retention in pigs supplemented with inorganic Se increased each week of the trial. When Se retention was expressed in relation to Se intake, the resulting regression was linear (R2 = .99), suggesting that Se retention in the postweaning pig increased in direct proportion to the amount consumed when diets contained up to 1.0 ppm Se.     

啤酒废酵母硒对肉鸡组织硒含量的影响

本试验旨在研究啤酒废酵母硒对肉鸡组织硒含量的影响。选用225羽1日龄平均体重为(42.78±1.08)g的AA商品代肉鸡(公母混合),随机分成5组,每组3个重复,每个重复15羽,对照组日粮为以Na2SeO3形式在基础日粮中补充硒0.1mg/kg,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组日粮为以酵母硒形式在基础日粮中补充硒0、0.1、0.2、0.3mg/kg,饲养期42d。结果表明:(1)肉鸡羽毛、肌肉和肝脏中硒的含量随着酵母硒添加量的增加和时间的延长显著提高,并表现出较强的线性关系;(2)与基础日粮组相比,酵母硒组肉鸡组织硒含量极显著增加(P0.05),以0.3mg/kg的添加量最好;硒的沉积顺序为肝脏羽毛肌肉。本试验结果提示,由啤酒废酵母制备的酵母硒可以提高肉鸡组织硒含量。     

Effect of selenium supplementation and source on the selenium status of horses

This study was conducted to determine the effect of Se supplementation and source on the Se status of horses. Eighteen 18-mo-old nonexercised horses were randomly assigned within sex to 1 of 3 treatments: 1) control (CTRL, no supplemental Se, 0.15 mg of Se/kg of total diet DM); 2) inorganic Se (INORG, CTRL + 0.45 mg of Se/kg of total diet DM from NaSeO3); or organic Se [ORG, CTRL + 0.45 mg of Se/kg of total diet DM from zinc-L-selenomethionine (Availa Se, Zinpro, Corp., Eden Prairie, MN)]. Horses were acclimated to the CTRL diet (7.1 kg of DM alfalfa hay and 1.2 kg of DM concentrate per horse daily) for 28 d. After the acclimation period, the appropriate treatment was top-dressed on the individually fed concentrate for 56 d. Jugular venous blood samples were collected on d 0, 28, and 56. Middle gluteal muscle biopsies were collected on d 0 and 56. Muscle and plasma were analyzed for Se concentrations. Glutathione peroxidase activity was measured in muscle (M GPx-1), plasma (P GPx-3), and red blood cells (RBC GPx-1). Data were analyzed as a repeated measures design. Mean plasma Se concentration on d 28 and 56 was greater (P < 0.05) for Se-supplemented horses compared with CTRL horses, and tended (P < 0.1) to be greater in ORG vs. INORG on d 28. Mean muscle Se concentration and P GPx-3 activities increased (P < 0.05) from d 0 to 56 but were not affected by treatment. Mean RBC GPx-1 activity tended to be greater (P < 0.1) in ORG than INORG or CTRL horses on d 28, and tended to be greater (P < 0.1) for INORG compared with ORG horses on d 56. Mean RBC GPx-1 activity of INORG and ORG horses was not different from that of CTRL on d 56. Mean M GPx-1 activity decreased (P < 0.01) from d 0 to 56. In conclusion, zinc-L-selenomethionine was more effective than NaSeO3 at increasing plasma Se concentration from d 0 to 28; however, both supplemental Se sources had a similar effect by d 56. No difference in Se status due to Se supplementation or source could be detected over a 56-d supplementation period by monitoring middle gluteal muscle Se, M GPx-1, or P GPx-3. Results for RBC GPx-1 also were inconclusive relative to the effect of Se supplementation and source.     

Effect of selenium source and dose on selenium status of mature horses

This study was conducted to determine the effects of either dietary Se source or dose on the Se status of horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments that comprised the same basal diet that differed only in Se source or dose. Treatments were as follows: negative control (0.085 mg of Se/kg of DM), 3 different dietary concentrations of supplemental organic Se (Se yeast; 0.2, 0.3, and 0.4 mg of total Se/kg of DM), and positive control (0.3 mg of total Se/kg of DM) supplemented with Na selenite. Horses initially received the control diet (6 kg of grass hay and 3 kg of concentrate per horse daily) for 56 d to allow diet adaptation. After the period of diet adaptation, horses were offered their respective treatments for a continuous period of 112 d. Jugular venous blood samples were collected before the morning feed on d 0, 28, 56, 84, and 112. Whole blood and plasma were analyzed for total Se, glutathione peroxidase activity in whole blood (GPX-1) and plasma, and thyroid hormones (thyroxine and triiodothyronine) in plasma. The proportion of total Se as selenomethionine (SeMet) or selenocysteine in pooled whole blood and plasma samples was determined on d 0, 56, and 112. Data were analyzed as repeated measures. Total Se in blood and plasma and GPX-1 activity were greater in all supplemented horses (P < 0.001, except P < 0.01 for GPX-1 in horses supplemented with the least dose of Se yeast) with a linear dose effect of Se yeast for whole blood and plasma Se (P < 0.001) and a quadratic dose effect (P < 0.05) for whole blood GPX-1 activity. A plateau for total Se in plasma was achieved within 75 to 90 d, although this was not observed in blood total Se or GPX-1 activity. On d 84 and 112, horses supplemented with Se yeast showed greater total Se in blood (P < 0.05) compared with horses supplemented with Na selenite, and a source effect (P < 0.05) was observed in the relationship between total blood Se and GPX-1 activity. Selenocysteine (the predominant form of Se in whole blood and plasma) increased in all horses supplemented with Se. The SeMet content of whole blood and plasma increased in horses supplemented with Se yeast, but it was not observed in those supplemented with selenite. The rate of increase in SeMet over time was greater in whole blood (P < 0.05) and plasma (P = 0.10) with the Se yeast product. In conclusion, Se yeast was more effective than Na selenite in increasing total Se in blood, mainly as consequence of a greater increase of the proportion of Se comprised as SeMet, but it did not modify GPX-1 activity.     

Thyroid hormone concentrations in selenium deficient and selenium sufficient cattle

Selenium deficient calves when compared to selenium supplemented calves had increased plasma thyroxine concentrations and decreased plasma tri-iodothyronine concentrations. These changes in the selenium deficient calves were accompanied by significant increases in plasma urea and creatinine concentrations and decreased plasma alkaline phosphatase activity. The demonstration that low selenium status can cause imbalances in thyroid hormone metabolism may provide an explanation for some of the effects of the deficiency.