施用猪粪对土壤Zn形态和菜心Zn含量的影响

采用盆栽试验的方法,研究施用猪粪对土壤和菜心Zn含量的影响,以为蔬菜安全施用畜禽粪便提供依据.结果表明,土壤全Zn、有效态Zn和菜心Zn含量均随猪粪施用量和施用茬数的增加而提高,连续2茬施用猪粪达到40g/kg时,土壤全Zn含量和菜心Zn含量分别达到266.42和21.03mg/kg,超过国家土壤质量二级标准(pH≤6...     

Effect of Excess Cadmium and Zinc Ions on Roots and Shoots of Maize Seedlings

The effect of 8-day-old exposure maize seedlings with cadmium (Cd) or zinc (Zn), separately, are described with special attention being given to ultrastructural changes as well as changes of the growth. These elements, frequent pollutants found in the soil, were added as 1 mM solutions to nutrient solution used for roots and shoots of maize seedlings, investigated 8 days after germination. The symptoms of heavy metal toxicity were clear showing that Cd inhibits root growth more strongly than the shoots and more effectively than zinc ions. The results of scanning electron microscopy revealed changes in the leaf surface, particularly in the guard cells of the stomata. The ultrastructural analyses of the parenchyma mesophyll cells showed extensive chloroplast disorganization, mainly affecting the thylakoid membranes and grana.     

The effect of salinity and iron application on growth and mineral uptake of sunflower (helianthus annuus L.)

In a greenhouse experiment, the effect of salinity and Fe chelate on growth and mineral uptake of sunflower (Helianthus annuus L. c.v. Record) was studied.

Sunflower plants were grown in nutrient solution with four levels of salinity (0, 1.5, 3.0 and 4.5 atm), induced by NaCl and four rates of Fe chelate (0, 0.5, 1.0 and 1.5, ppm Fe) as FeEDDHA. The experiment was a completely randomized design with treatment combinations arranged in a factorial manner with three replications.

Dry matter yield, shoot‐root ratio, leaf area, plant height and transpiration decreased as salinity increased, the effect of salinity being depressed by iron applications. Salinity reduced P, K, Ca and Mg uptake by roots as well as that of N, P, K, Ca, Mg by shoots, while Fe applications increased uptake of these elements in roots and shoots. Both salinity and iron applications increased Cl, Na and Fe uptake by roots and shoots, as expected. In most instances salinity reduced uptake of Fe, Mn and Zn by the plants while iron applications improved uptake of these elements.

The sunflower plant used in this experiment was found to be, at least partly, tolerant to salinity and decreased water availability as well as toxicity of ions. Nutritional disorders were the cause of decreased plant growth by increasing salinity of the nutrient solution. The decreased plant growth and mineral uptake, induced by salinity, were partially offset by increased iron levels in the nutrient solution.     

Tolerance of Two Hydroponically Grown Salix Genotypes to Excess Zinc

Woody cuttings from two Salix genotypes (genotype I—clone LUC-31, Salix alba and genotype II- clone STOTT, Salix viminalis) were grown hydroponically for 14 days at increasing concentrations of Zn: control, 50, 100 or 150 μ M Zn. Genotype tolerance to excess zinc (Zn) was evaluated using a root elongation test. The changes in growth, Zn, iron (Fe), copper (Cu) and manganese (Mn) concentrations as well as photosynthetic performance were used as additional evaluation criteria. Photosynthetic pigments concentrations in Zn-exposed cuttings of genotype II decreased as compared with genotype I, which corresponded well with the higher leaf Zn accumulation, decreased Fe concentrations as well as lowered photosynthetic rate. Based on the indicators used, genotype I (Salix alba) was classified as more tolerant to excess Zn than genotype II (Salix viminalis).     

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.     

平凉地区旱地玉米覆盖栽培硫酸锌施用技术

研究总结出玉米喷施硫酸锌最佳用量为 3.0 0 kg/ hm2 ,拌种最佳用量为 2 5 .4 g/ kg,其中拌种用量远远大于资料介绍的 4～ 6g/ kg的界限 [1] 。硫酸锌的增产效果为 :基施 (10 .5 %～31.5 % ) >拌种 (17.7% ) >喷施 (14.6% )。并应用模糊聚类法对 4年 2 8点次旱地覆盖栽培玉米基施硫酸锌试验资料进行分析 ,得到了各类区的肥料效应方程式 ,利用各方程计算得到硫酸锌基施的最佳用量为 2 3.18～ 31.74 kg/ hm2 。     

Iron and zinc accumulation in winter wheat regulated by NICOTIANAMINE SYNTHASE responded to increasing nitrogen levels

Nitrogen (N) is critical for micronutrient biofortification in wheat grain and is essential for a series of nitrogenous compounds biosynthesis. This study aims to assess the role of improved N supply in iron (Fe) and zinc (Zn) enrichment and expression of genes related to Zn and Fe chelation and transport in winter wheat. Potting and hydroponic culture experiments were conducted to study the effect of increasing N application on Zn and Fe uptake and translocation from roots to leaves and the temporal and spatial gene expression profiles of the NICOTIANAMINE SYNTHASE (NAS) genes in wheat. Plants were grown with low, medium and high N supply levels. The results showed that higher N application increased Fe and Zn content in leaves, and decreased Fe and Zn content in root compared with the lower N supply. High N application also increased the distribution of Fe and Zn from roots to leaves. Expression analysis showed that increased N application resulted in up-regulation of two wheat NAS genes, TaNAS1 and TaNAS2. Highly positive response between NAS genes and increasing N application indicated that abundance nicotianamine (NA) resulted from highly expressed NAS genes might involve in the chelation of Fe and Zn in the phloem and favor Fe and Zn uptake and accumulation in wheat leaves.     

硫酸盐对锌和镉在可变电荷土壤上吸附的影响

SO4^2- and Zn^2 or Cd^2 were added to three variable charge soils in different sequences.In one sequence sulfate was added first ,and in the other,Zn^2 or Cd^2 first.The addition of sulfate to the system invariably caused an increase in adsorption of the heavy metal added,with the effect more remarkable whn the soil reacted with the sulfate prior to the metal.the shift in pH50 for both Zn and Cd adsorption was aslo comparatively larger in the first sequence of reactions .It was suggested that the increase in negative charge density and the resultant negative potential of the soil were the primary cause of the pronounced effect of sulfate on adsorption of Zn or Cd,and the formaiton of the ternary surface complex-S-SO4-M might also play a role in the effect.     

Effects of planting soybean in summer fallow on wheat grain yield,total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200 m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089 kg ha⁻¹ at the 108 kg N ha⁻¹ rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.