Frequency distribution of several trace metals in 72 corn plants grown together in contaminated soil in a glasshouse

Abstract

A 9‐kg quantity of Yolo loam soil was contaminated in sequence with (In μg/g soil) 100 Cd, 100 Zn, 100 Co, 12.5 Li, and 100 Ni. Corn (Zea mays L. C. V. Golden Cross N. C. ) was grown together in the soil for 22 days from seed. Seventy‐two harvested plants were assayed separately. Several different trace metals were tested for normal and loge frequency distribution patterns. Some followed log_e normal distribution more closely than a normal distribution as indicated by kurtosis values. Two followed normal distribution more closely than log_e normal distribution. Some negative skewness was observed with the log_e normal distribution, but only that for Co was significant. The yields of the plants were significantly and negatively correlated with the concentrations of Ni, Co, Cu, and Cd in shoots. Stepwise regression analysis indicated that it was reasonably Possible to determine which of the trace metals of the mixture caused phytotoxicity. Some pairs of trace metals were highly and positively correlated: Zn‐Cu, Zn‐Cd, Cu‐Cd, Mn‐Li, Co‐Ni, Co‐Cd are examples. The mixed trace metals decreased shoot concentrations of P and Mo and increased Al and Ti relative to control plants not receiving added metals. The Si was also decreased by trace metals and was positively related to yields.     

硒、钴对苜蓿青干草营养水平影响的研究

通过在苜蓿草地上基施硒、钴物料的田间试验,研究苜蓿对硒钴的吸收、积累和转化特点,以及各种物料对苜蓿青干草中营养成分和微量元素含量的影响。结果表明: （1）硒或钴物料均能提高苜蓿青干草中硒的含量,物料中硒含量越高,青干草中硒的含量也越高。钴能显著提高苜蓿青干草中的钴含量,过量施钴会造成钴料的浪费。虽然硒对草中钴积累量影响不大,但硒钴混合物料可显著提高牧草钴的积累量,物料中硒含量越高草中钴的积累量越多。（2）硒钴的合理混施能显著提高苜蓿对硒、钴的利用率以及物料中无机硒向牧草中有机硒的转化率,提高牧草中硒的有效性和安全性。（3）在所有硒、钴物料中,高硒低钴能提高苜蓿青干草的粗蛋白和粗脂肪含量,对粗纤维和无氮浸出物影响不大。而其他硒、钴物料均能显著提高苜蓿干草中的粗纤维含量,降低粗脂肪含量,对粗蛋白和无氮浸出物含量影响不大。（4）硒钴混合物料能显著提高苜蓿青干草中Mo、Cu、B、Fe、Mn、Zn 6种元素的含量,其中Mo的提高幅度最大为142.34 %～256.45 %, 其次为Fe、Mn和Zn,提高幅度分别为48.16 %～59.45 %、32.88 %～41.66 %和37.10 %～96.39 %。Cu和B的提高幅度最小,分别为13.43 %～37.33 %和14.60 %～39.67 %。     

硒、钴单施和配施对苜蓿生长及产量的效应研究

为探讨硒、钴在提高苜蓿生长影响,在河南省沿黄滩区,开展了硒、钴单施和配施下对紫花苜蓿生长以及产量和品质影响研究。结果表明,硒、钴单施和配合基施均能够显著提高苜蓿从现蕾到开花期的净光合能力,降低呼吸消耗,提高单位叶面积干物质的生产速率,有利于苜蓿花前青干草生产和果实发育;其中,以硒570 g/hm2、钴762g/hm2配施下效果显著,青干草增产8.06%,种子千粒重可提高12.85%。单施钴和硒钴配施还能促进0—20 cm耕层苜蓿根瘤菌的生长和积累,增强苜蓿的固氮能力。说明硒钴合理基施对苜蓿青干草和优质种子生产具有很好的应用效果。     

花篮源的排布及其剂量场参数测定

结合江西省农业科学院原子能应用研究所１９９７年增源和安全运行１５个月后的两次剂量场参数的测定，探讨了花篮源的源棒排布方案和依据，介绍了辐照剂量场的测定方法并论证了其为最佳分布。     

Cobalt metabolism in horse. Serum level and biosynthesis of vitamin B12.

The levels of serum vitamin B₁₂ were determined on 16 mature partly warm-blooded, partly Finnish rural-race horses by the radioisotopic competitive inhibition assay method. The mean value from three samplings carried out in dupli- or triplicate was 1.54 ± 0.16 ng/ml. The utilization of serum inorganic cobalt for cyanocobalamin synthesis was studied on two geldings, which received a dose of 200 µCi ⁵⁸CoGl₂ i.v. A Sephadex G-100 gel filtration was carried out with the serum proteins from serial blood samplings at different time intervals 15 min. to 48 hrs. after administration. The gel filtration showed the presence of two labelled proteins in the serum, one of them appearing some time after administration and disappearing almost completely towards the end of the experimental period. The two elution peaks are considered to represent inorganic ⁵⁸Co and ⁵⁸Co labelled vitamin B₁₂. The appearance of labelling in serum vitamin B₁₂ indicates the passing of cobalt into the intestine, and reabsorption into blood in the form of vitamin B₁₂.     

影响土壤中铬, 锰的氧化还原反应的环境因素

Disposal of chromium(Cr) hexavalent form,Cr(VI),in soils as additions in organic fertilizers,liming materials or plant nutrient sources can be dangerous since Cr(VI) can be highly toxic to plants,animals,and humans.In order to explore soil conditions that lead to Cr(VI) generation,this study were performed using a Paleudult(Dystic Nitosol) from a region that has a high concentration of tannery operations in the Rio Grande do Sul State,southern Brazil.Three laboratory incubation experiments were carried out to examine the influences of soil moisture content and concentration of cobalt and organic matter additions on soil Cr(VI) formation and release and manganese(Mn) oxide reduction with a salt of chromium chloride(CrCl 3) and tannery sludge as inorganic and organic sources of Cr(III),respectively.The amount of Cr(III) oxidation depended on the concentration of easily reducible Mn oxides and the oxidation was more intense at the soil water contents in which Mn(III/IV) oxides were more stable.Soluble organic compounds in soil decreased Cr(VI) formation due to Cr(III) complexation.This mechanism also resulted in the decrease in the oxidation of Cr(III) due to the tannery sludge additions.Chromium(III) oxidation to Cr(VI) at the solid/solution interface involved the following mechanisms:the formation of a precursor complex on manganese(Mn) oxide surfaces,followed by electron transfer from Cr(III) to Mn(III or IV),the formation of a successor complex with Mn(II) and Cr(VI),and the breakdown of the successor complex and release of Mn(II) and Cr(VI) into the soil solution.     

5－溴水杨基荧光酮－Co（Ⅱ）－CTMAB的吸附伏安行为

在ｐＲ４．０的磷酸盐缓冲溶液中，５－溴水杨基荧光酮－Ｃｏ（Ⅱ）－ＣＴＭＡＢ可形成稳定的三元配合物．将此配合物预富集在玻碳电极表面，阴极溶出时可产生一个灵敏的吸附还原波，其还原峰电位在－０．７６Ｖ．峰电流与钴（Ⅱ）的浓度在５．０×１０－５－１．０×１０－７ｍｏｌ／Ｌ之间有良好的线性关系．     

钴肥对大豆根瘤固氮及产量影响的初报

试验用硫酸钴拌种，经测定，在盛花期和结荚期大豆株高、干物重及根瘤固氮酶活性和固氮强度与对照相比均有不同幅度增加，收获后大豆籽粒产量与对照差异达显著水平。     

Reduction of the prevalence of footrot on New Zealand farms by vaccination

AIM: To compare serum analyses of vitamin B₁₂ and methylmalonic acid (MMA) as indices of cobalt/vitamin B₁₂ deficiency in lambs around weaning.

METHODS: Lambs on five properties, considered to be cobalt- deficient, were supplemented with either cobalt bullets, or short- or long-acting vitamin B₁₂ preparations. Blood samples, and in some cases liver biopsies, and liveweights were obtained at monthly intervals. Serum samples were assayed for vitamin B₁₂ and MMA and liver for vitamin B₁₂ concentrations. Pasture cobalt concentrations were measured on three of the properties.

RESULTS: Pasture cobalt concentrations were generally maintained below 0.07 μg/g dry matter (DM) on the properties sampled. Growth responses to supplementation were observed on only 2/5 properties, despite serum vitamin B12 concentrations being within the currently used ’marginal‘ reference range (336–499 pmol/L) for at least 3 months on all properties and in the deficient reference range (0–335 pmol/L) for at least 2 months on all farms except one. Serum MMA concentrations in supplemented lambs were <2 μmol/L, except in those animals sampled 1 month after receiving treatment with a short-acting vitamin B12 injection. Serum MMA concentrations in unsupplemented animals on properties on which no growth response to supplementation occurred generally reached peak levels of between 4 and 7 μmol/L at the nadir of serum vitamin B12 concentration. When a growth response was observed, differences in weight gain between supplemented and unsupplemented lambs occurred as mean serum MMA concentrations increased from 9 to 14 μmol/L. On one property where supplementation commenced before weaning, normal growth rates were maintained despite serum vitamin B12 concentrations of 140 pmol/L and serum MMA concentrations in excess of 40 μmol/L serum.

CONCLUSIONS: The possibility that current serum vitamin B₁₂ references ranges for diagnosis of cobalt deficiency are set too high and lead to over-diagnosis of responsiveness to cobalt/ vitamin B₁₂ supplementation is discussed. The suggestion is made that serum MMA concentrations in excess of 9–14 μmol/L will provide a more reliable diagnostic test for cobalt deficiency. However, there was sufficient variation between properties in the relationships between cobalt concentrations of pasture and serum vitamin B₁₂ or MMA concentrations to require more rigorous testing of the reliability of using serum MMA concentration for this purpose. The possibility that differences in rumen fermentation and therefore propionate and vitamin B₁₂ production could be involved is discussed. The measurement of serum MMA and vitamin B₁₂ appears to be of little value whilst the lamb is still suckling.

CLINICAL SIGNIFICANCE: Serum MMA concentration may offer advantages over serum vitamin B₁₂ concentrations in the diagnosis of a cobalt/vitamin B₁₂ responsiveness in weaned lambs.     

乙酰丙酮缩邻苯二胺及其Co(Ⅱ)配合物的微波合成

采用微波辐射方法合成了乙酰丙酮缩邻苯二胺Schiff碱及其Co(II)金属配合物;通过红外光谱、元素分析、质谱、熔点仪对Schiff碱及其配合物进行了表征。