铁和维生素A及其互作效应对肉仔鸡组织铁含量和营养物质表观存留率的影响

选用1日龄艾维茵肉仔鸡504只 ,随机分为9组 ,每组4个重复 ,每重复14只鸡 ,公母各半 ,采用3×3(Fe×VA)完全随机试验设计 ,研究了日粮添加不同水平Fe(0、30、60mg/kg)和VA(750、1500、2700IU/kg)对肉仔鸡不同生长阶段 (0～4周龄和5～7周龄 )肝脏、心脏、脾脏、胰脏、肾脏、肌肉、胫骨、羽毛等组织铁含量影响。结果表明 :在日粮铁的影响下 ,肉仔鸡体内各组织铁含量顺序依次为 :(前期 :肝脏>肾脏>脾>心脏>胫骨>毛>胰脏>肌肉 ;后期 :肝脏>脾>肾脏>心脏>胫骨>羽毛>胰脏>肌肉 ) ;日粮铁添加水平对前期肝脏、心脏、肾脏、胰脏、羽毛等组织铁含量影响显著 (P<0.01) ,60mgFe/kg 组这些组织铁含量最高 ;对后期肝脏、心脏、脾脏、胰脏、肌肉、胫骨、羽毛等组织的铁含量影响显著 (P<0.01) ,60mgFe/kg组肝脏与心脏组织铁含量最高 ,30mgFe/kg 组脾脏、肌肉、胫骨等组织铁含量最高 ,0mgFe/kg 组胰脏、羽毛等组织铁含量最高 ;肾脏、胰脏、羽毛、肌肉、胫骨在不同生长阶段沉积铁能力不同。日粮铁对不同生长阶段各组织铁含量的影响存在差异。VA影响机体内铁的分布 ,日粮VA添加水平对前期肾脏、肌肉、羽毛等组织铁含量影响显著 (P<0.01) ,对后期肝脏、肾脏、胰脏、肌肉、胫骨、羽毛等组织铁含量影响显著 (P<0.01)。VA对前后     

Prospects of breeding biofortified pearl millet with high grain iron and zinc content

Development of crop cultivars with elevated levels of micronutrients is being increasingly recognized as one of the approaches to provide sustainable solutions to various health problems associated with micronutrient malnutrition, especially in developing countries. To assess the prospects of this approach in pearl millet (Pennisetum glaucum), a diverse range of genetic materials, consisting of 40 hybrid parents, 30 each of population progenies and improved populations, and 20 germplasm accessions, was analysed for grain iron (Fe) and zinc (Zn) content, deficiencies of which adversely affect human health. Based on the mean performance in two seasons at ICRISAT, Patancheru, India, large variability among the entries was found, both for Fe (30.1–75.7 mg/kg on dry weight basis) and Zn (24.5–64.8 mg/kg). The highest levels of grain Fe and Zn were observed in well‐adapted commercial varieties and their progenies, and in the parental lines of hybrids, which were either entirely based on iniari germplasm, or had large components of it in their parentage. There were indications of large within‐population genetic variability for both Fe and Zn. The correlation between Fe and Zn content was positive and highly significant (r = 0.84; P < 0.01). These results indicate that there are good prospects of simultaneous selection for both micronutrients, and that selection within populations, especially those with the predominantly iniari germplasm, is likely to provide good opportunities for developing pearl millet varieties and hybrid parents with significantly improved grain Fe and Zn content in pearl millet.     

Pretreatment of Coke Oven Waste Water with Blast Furnace Sludge Method and Blast Furnace Sludge Plus Scrap Iron Method

Coke oven waste water is respectively pretreated by blast furnace sludge method and blast furnace sludge plus iron scrap method, the effects of pH and the quantity of materials and treatment time on the removal efficiency of COD are analyzed. The results indicate that blast furnace sludge plus iron scrap method is superior to blast furnace sludge method .The treatment time and pH can greatly affect on the removal efficiency of COD using blast furnace sludge plus iron scrap method. The treatment time after 30 minutes and pH have no remarkable effects the removal efficiency of COD using blast furnace sludge method. The removal efficiency of COD increases with the increase of blast furnace sludge and iron scrap, but the increase rate decreases gradually.     

钙盐诱导下土壤锰和铁的释放及其对胡椒的生物有效性

Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability to pepper (Capsicum frutescens L.) were studied in a pot experiment. Addition of Ca(NO₃)₂ decreased soil pH and increased both exchangeable and DTPA (diethylenetriamine pentaacetic acid)-extractable Mn and Fe in soils. Meanwhile, total Mn accumulation in the shoots of Capsicum frutescens L. on the salt-treated soils increased significantly (P< 0.01) compared with the control, suggesting that salt addition to soil induced Mn toxicity in Capsicum frutescens L. Although exchangeable and DTPA-extractable Fe increased also in the salt-treated soils, Fe uptake by the shoots of Capsicum frutescens L. decreased. The effect of added salts in soils on dry matter weight of pepper varied with the soil characteristics, showing different buffer capacities of the soils for salt toxicity in an order of yellow-brown soil > albic soil > yellow-red soil. Fe/Mn ratio in shoots of Capsicum frutescens L. decreased with increasing salt addition for all the soils, which was ascribed to the antagonistic effect of Mn on Fe accumulation. The ratio of Fe/Mn in the tissue was a better indicator of the appearance of Mn toxicity symptoms than Mn concentration alone.     

干湿交替对作物根际特征及铁膜形成的影响研究进展

铁膜普遍存在于水生植物的根系表面,根际周围Fe~(2+)的浓度和根系氧化力决定了根表铁膜的数量。干湿交替是农业生产中常用的灌溉技术。在干湿交替过程中,水分和氧气含量的变化导致根际土壤发生一系列物理、化学和生物学变化,从而对根表铁膜的形成产生影响。本文综述了干湿交替过程对根际特征变化的影响,分析了根表铁膜的形成条件、化学组成与空间结构和根表铁膜的形成过程,并在此基础上探讨了干湿交替对铁膜形成的影响以及干湿交替诱导铁膜形成的可能机制。最后对干湿交替诱导铁膜形成的研究方法与应用前景进行了展望。     

土壤悬浮液中溶解和吸附性铁离子对硫化物还原Cr(VI)的催化作用

The kinetics of Cr(Ⅵ) reduction by sulfide in soil suspensions with various pHs, soil compositions, and Fe(Ⅱ) concentrations was examined using batch anaerobic experimental systems at constant temperature. The results showed that the reaction rate of Cr(Ⅵ) reduction was in the order of red soil < yellow-brown soil < chernozem and was proportional to the concentration of HCl-extractable iron in the soils. Dissolved and adsorbed iron in soil suspensions played an important role in accelerating Cr(Ⅵ) reduction. The reaction involved in the Cr(Ⅵ) reduction by Fe(Ⅱ) to produce Fe(Ⅲ), which was reduced to Fe(Ⅱ) again by sulfide, could represent the catalytic pathway until about 70% of the initially present Cr(Ⅵ) was reduced. The catalysis occurred because the one-step reduction of Cr(Ⅵ) by sulfide was slower than the two-step process consisting of rapid Cr(Ⅵ) reduction by Fe(Ⅱ) followed by Fe(Ⅲ) reduction by sulfide. In essence, Fe(Ⅱ)/Fe(Ⅲ) species shuttle electrons from sulfide to Cr(Ⅵ), facilitating the reaction. The effect of iron, however, could be completely blocked by adding a strong Fe(Ⅱ)-complexing ligand, 1,10-phenanthroline, to the soil suspensions. In all the experiments, initial sulfide concentration was much higher than initial Cr(Ⅵ) concentration. The plots of lnc[Cr(Ⅵ)] versus reaction time were linear up to approximately 70% of Cr(Ⅵ) reduction, suggesting a first-order reaction kinetics with respect to Cr(Ⅵ). Elemental sulfur, the product of sulfide oxidation, was found to accelerate Cr(Ⅵ) reduction at a later stage of the reaction, resulting in deⅥation from linearity for the lnc[Cr(Ⅵ)] versus time plots.     

温度对酸性草酸-草酸铵溶液浸提土壤无定形铁的影响

以下蜀黄土为试材,研究温度对酸性草酸-草酸铵缓冲溶液浸提土壤无定形铁的影响。结果表明:随着浸提温度的升高,铁的浸提量明显增加。30℃浸提出的铁约为20℃的1.57倍;而50℃浸提出的铁约为20℃的4.43倍。随温度的升高,浸提后土壤残渣的磁化率迅速降低。20℃浸提后残渣的磁化率值比原样略有减少;30℃浸提后残渣的磁化率约为原样的93.6%;50℃浸提后残渣的磁化率只有原样的65.3%。这说明随着温度的升高,以磁性矿物为代表的结晶态铁也被溶解,浸提出的铁其实已不仅是无定形铁。因此,用酸性草酸铵浸提无定形铁时,严格控制20℃的反应温度十分关键。     

增铵对小白菜生长和叶绿素含量的影响

在营养液中添加一定量的铵态氮能提高作物生物量和叶绿素含量。为研究增铵对植物生长及叶绿素含量的影响机理,采用了6个NO3-∶NH4 浓度比为5·0∶0·0、5·0∶2·5、5·0∶5·0、5·0∶7·5、5·0∶10·0和0·0∶5·0的处理对小白菜进行培养试验。结果表明,在5mmolL-1硝态氮存在时,适当添加一定量的铵态氮(2·5mmolL-1)小白菜生物量和叶面积分别增加39·6%和16·3%,叶面积与生物量显著相关(r=0·941,p<0·01)。营养液中铵态氮浓度与叶片SPAD值、活性铁及叶绿体蛋白质含量均显著相关,相关系数r分别为0·914、0·954和0·964。适当提高铵态氮浓度增加小白菜产量的机制在于其促进了叶片扩展,提高了总光合面积,其原因可能是适当提高铵态氮浓度促进了叶片细胞分裂。进一步研究表明,提高铵态氮浓度提高叶绿素含量的原因,可能在于其促进了小白菜体内全铁的再利用,从而提高了叶片活性铁含量和叶绿体蛋白质含量。     

Characterization of brushite as a re-crystallization product formed during bacterial solubilization of hydroxyapatite in batch cultures

Two strains of bacteria (Burkholderia sp., strain FeGL01, and Burkholderia caribiensis, strain FeGL03) were isolated from a Brazilian high phosphorus iron ore. The capacity of both strains to solubilize hydroxyapatite, Ca₅(PO₄)₃(OH), was assessed in plate and batch cultures. In batch cultures, the concentration of solution-P showed two kinetics: an initial one, characterized by a continuously increasing kinetics and a second one, characterized by oscillatory kinetics. To understand the nature of these oscillations, phosphatic residues in the spent broth were collected before, during and after the oscillations, and characterized using scanning electron microscopy (SEM), energy-dispersive X-ray chemical microanalyses (EDX) and X-ray diffraction (XRD). From these studies, it was found that drops in P concentration were related to the formation of an intermediate phosphate in the residues, identified as brushite, CaHPO₄·2H₂O. Later increase of available P in the solution was found to be a consequence of re-dissolution of brushite crystals previously formed. Re-crystallization of brushite was also detected in plate cultures after 12-14 days of incubation