Cu induced changes of ultrastructure and bioaccumulation in the leaf of Moso bamboo (Phyllostachys pubescens)

The effects of Copper (Cu) on growth of Moso bamboo (Phyllostachys heterocycla (Carr.) Mitford cv. pubescens) were investigated. The dry weight of Moso bamboo was inhibited and significant differences were evident under Cu stress as compared to the control (CK). Solution culture experiments indicated that Moso bamboo had a strong ability to accumulate Cu in shoots. Copper accumulation in the stem was stronger than the leaves; the stem/root ratio could reach 0.20 under Cu stress. The changes in cell walls, stomata, vacuoles, and starch grains content were observed via scanning electron microscopy and transmission electron microscopy. The ultrastructural analysis revealed that the excessive Cu concentrations caused deformities in the chloroplasts and transformation and even disappearance of endoplasmic reticulum. Moso bamboo as an experimental material serves as a new tool for remediation of heavy metal contaminated soils due to its metal tolerance and excessive biomass production.     

Effects of foliar spraying with new zinc sources on rice seed enrichment,nutrition, and productivity

New Zn sources have emerged recently, which may boost the beneficial effects of leaf sprays on rice cropping. Thus, this study aimed to compare the effects of foliar sprays using Zn chelate against those with new Zn sources such as sorbitol-stabilised Zn nitrate and Zn oxide nanoparticles on rice seed enrichment and production. Treatments were arranged in a completely randomised design, comprising of three Zn sources and four Zn concentrations with four replicates. Rice plants were sprayed three times: at the beginning of tillering, maximum tillering, and booting stage. Experimental unity consisted of 7-dm³ pots filled with 5-dm³ medium textured sand. Each pot had 10 plants, of which 6 randomly harvested at the flowering stage and the remaining at the maturity stage. Plant dry matter, content and accumulation of Zn in the shoot, seed Zn content, and seed production at the grain-filling stage were also estimated. Seed production and Zn accumulation showed a quadratic behaviour with the use of novel sources. Overall the new Zn sources were more effective than the traditional EDTA chelated Zn in terms of rice seed production and quality, especially the sorbitol-stabilised Zn nitrate.     

激素,微肥对毛竹林发笋,成竹数量的影响

为探索提高毛竹笋芽萌发率的途径,本试验用随机区组和正交设计方法在毛竹成林内分别布置了三个对比试验,以研究施用激素,微肥和硝酸稀土等外源物质对毛竹成林发笋和成竹数量的影响效应。对连续4年的观测分析表明,试验条件的毛竹林施用硝酸稀土处理的发笋数和成竹数与对照相比差异显著,且毛竹林对其施用浓度有较大的适应范围。施用激素和微肥处理的毛竹成林的发笋、成竹数与对照相比差异不显著,且较大浓度的微肥处理对发笋和成竹有不利影响。     

玉米低植酸突变体的营养品质分析

对比研究了8个玉米低植酸(Low phytic acid,lpa)突变体及其相应野生型(Wild Type,WT)的主要营养品质及其营养组分,结果显示:与野生型相比,各突变体总磷含量基本不变,无机磷含量均成倍增加,总淀粉含量显著下降,直链淀粉和粗脂肪含量变化不显著,粗蛋白含量在部分突变体中显著上升;多数氨基酸含量在突变体中有所提高,赖氨酸含量除Q319-lpa和X178-lpa下降外均不同程度上升;铁、锰、铜、锌、硒等微量元素含量变化不显著。研究表明lpa突变对玉米营养品质的改良和生物学效价的提高具有有益的作用。     

菜园土肥力特征及蔬菜硝酸盐污染的控制技术Ⅲ.喷施稀土微肥对小白菜硝酸盐含量的影响

为提高蔬菜品质,并有效控制蔬菜中硝酸盐的积累,通过田间小区试验,研究了红菜园上和冲积菜园土条件下喷施稀土、铜肥、钼肥、锌肥、锰肥、硼肥后小白菜硝酸盐和亚硝酸盐含量的变化及对其他品质的影响．结果表明：喷施钼肥和锰肥降低蔬菜硝酸盐含量效果最佳,也显著增强了硝酸盐还原酶的活性．     

Synthesis and characterization of zinc-coated urea fertilizer

The research was focused on the synthesis and characterization of zinc (Zn)-coated urea fertilizer. Zinc oxide (ZnO) particles were coated on urea granules through two different coating techniques, i.e., slurry coating and wet coating, and the release rate of the coated Zn was measured up to 24 hours. Slurry coating technique showed better Zn release rate and morphology of coated urea granules as compared with wet coating technique using different binders, i.e., water, molasses, paraffin oil, and the combined mixture of honey bee wax and gum arabica. Urea granules synthesized through wet coating technique have a low amount of Zn as compared with slurry-coated urea granules. Urea granules coated through slurry coating technique and molasses, paraffin oil, and water (MPW) as a binder were the best in term of coating efficiency, uniform size distribution of ZnO-coated particles, granule's morphology, and release rate of Zn from coated formulations.     

Relation of Toxicity in Corn Seeds Treated with Zinc and Salicylic Acid

The beneficial effect of corn seed treatment with zinc (Zn) is directly related to the source used. The excess of this micronutrient causes seedling stress and reduces growth. Thus, assuming that the use of exogenous phytohormones can minimize such effects, we evaluated different doses and sources of Zn for the treatment of maize seeds with or without salicylic acid. The experiment took place in the laboratory, and two factorial experiments, 2 × 4 + 1, were performed in a randomized design. The seeds were treated with either ZnO or ZnSO₄ at doses of 0.5, 1, 2, and 3 g.kg^?1 seed with four replications, differing only by the addition of 4.14 mg L^?1 salicylic acid. Treating seeds with Zn and salicylic acid did not affect germination. ZnO led to a greater increase in dry mass in corn seedlings as compared with zinc sulfate, especially at higher doses (2 and 3 g kg^?1 seed). Seed treatment with sulfate reduces root and shoot length, and salicylic acid did not attenuate this toxic effect. Dry mass is not affected when oxide is used. Salicylic acid reduces the accumulation of zinc in the treatment of corn seeds, regardless of the source used.     

桃源县植烟土壤微量元素与烟叶常规化学成分相关性分析

为探究土壤微量元素与烟叶常规化学成分的关联程度,及为提高烟叶质量提供理论依据,运用描述统计、简单相关和典型相关统计分析方法,研究了湖南省桃源县烟区植烟土壤微量元素与烟叶常规化学成分的关系。结果表明,桃源县烟区土壤中铁、锰、锌、铜、硼和钼含量平均值均在适宜范围及以上水平;土壤有效铜含量与烟叶中钾含量呈极显著负相关;土壤有效硼含量与烟叶中还原糖、总糖、氯含量和糖碱比呈极显著正相关,与总氮、蛋白质含量和钾氯比呈极显著负相关;土壤有效钼含量与还原糖含量、总糖含量和糖碱比呈极显著负相关,与总氮和蛋白质含量呈极显著正相关;土壤微量元素含量对烟叶常规化学成分的影响为有效硼>有效钼>有效锰>有效锌>有效铁>有效铜。通过典型相关分析表明,随着桃源县土壤有效锰和有效硼含量的减少或者有效钼含量的增加,能够引起烤后烟叶烟碱、总氮、蛋白质含量和钾氯比的增加以及还原糖、总糖、氯含量和糖碱比的降低。     

Surface Liming and Zinc Availability in a Long‐Term Experiment under No‐Till System

No‐till (NT) system with crop rotation is one of the most effective strategies to improve agricultural sustainability in tropical and subtropical regions. To control soil acidity in NT, lime is broadcast on the surface without incorporation. The increase in soil pH due to surface liming may decrease zinc (Zn) availability and its uptake by crops. A field experiment was performed in Paraná State, Brazil, on a loamy, kaolinitic, thermic Typic Hapludox to evaluate Zn bioavailability in a NT system after surface liming and re‐liming. Dolomitic lime was surface applied on the main plots in July 1993 at the rates of 0, 2, 4, and 6 Mg ha^?1. In June 2000, the main plots were divided in two subplots to study of the effect of surface re‐liming at the rates of 0 and 3 Mg ha^?1. The cropping sequence was soybean [Glycine max (L.) Merrill] (2001–2 and 2002–3), wheat (Triticum aestivum L.) (2003), soybean (2003–4), corn (Zea mays L.) (2004–5), and soybean (2005–6). Soil samples were collected at the following depths: 0–0.05, 0.05–0.10, and 0.10–0.20 m, 10 years after surface liming and 3 years after surface re‐liming. Soil Zn levels were extracted by four extractants: (i) 0.005 mol L^?1 diethylenetriaminepentaacetic acid (DTPA) + 0.1 mol L^?1 triethanolamine (TEA) + 0.01 mol L^?1 calcium chloride (CaCl₂) solution at pH 7.3 (DTPA–TEA), (ii) 0.1 mol L^?1 hydrochloric acid (HCl) solution, (iii) Mehlich 1 solution, and (iv) Mehlich 3 solution. Zinc concentrations in leaves and grains of soybean, wheat, and corn were also determined. Soil pH (0.01 mol L^?1 CaCl₂ suspension) varied from 4.4 to 6.1, at the 0‐ to 0.05‐m depth, from 4.2 to 5.3 at the 0.05‐ to 0.10‐m depth, and from 4.2 to 4.8 at the 0.10‐ to 0.20‐m depth, after liming and re‐liming. Zinc concentrations evaluated by DTPA–TEA, 0.1 mol L^?1 HCl, Mehlich 1, and Mehlich 3 solutions were not changed as a result of lime rate application. Re‐liming increased Zn concentrations extracted by 0.1 mol L^?1 HCl at 0–0.05 m deep and by DTPA–TEA at 0.05–0.10 m deep. Surface‐applied lime promoted a decrease in Zn concentrations of the crops, mainly in grains, because of increased soil pH at the surface layers. Regardless of the liming treatments, levels of Zn were sufficient to soybean, wheat, and corn nutrition under NT.     

Biochar application to temperate soils: Effects on soil fertility and crop growth under greenhouse conditions

Biochar (BC) application as a soil amendment has aroused much interest and was found to considerably improve soil nutrient status and crop yields on poor, tropical soils. However, information on the effect of BC on temperate soils is still insufficient, with effects expected to differ from tropical soils. We investigated the effects of BC on soil nutrient dynamics, crop yield, and quality in a greenhouse pot experiment. We compared three agricultural soils (Planosol, Cambisol, Chernozem), and BCs of three different feedstocks (wheat straw [WS], mixed woodchips [WC], vineyard pruning [VP]) slowly pyrolyzed at 525°C, of which the latter was also pyrolyzed at 400°C. The BCs were applied at two rates (1% and 3%, which would correspond to 30 and 90 t ha^–1 in the field). Three crops, namely mustard (Sinapis alba L.), barley (Hordeum vulgare L.), and red clover (Trifolium pretense L.) were grown successively within one year. The investigated soil properties included pH, electrical conductivity (EC), cation‐exchange capacity (CEC), calcium‐acetate‐lactate (CAL)–extractable P (P_CAL) and K (K_CAL), C, N, and nitrogen‐supplying potential (NSP). The results show a pH increase in all soils. The CEC increased only on the Planosol. The C : N ratio increased at 3% application rate. Despite improving the soil nutrient status partly, yields of the first crop (mustard) and to a lesser extent of the second crop (barley) were significantly depressed through BC application (by up to 68%); the yield of clover as third crop was not affected. Only the BC from WS maintained yields in the range of the control and even increased barley yield by 6%. The initial yield reduction was accompanied by notable decreases (Cu, Fe, Mn, Zn) and increases (Mo) in micronutrient concentrations of plant tissues while nitrogen concentrations were hardly affected. The results of the pot experiment show that despite additional mineral fertilization, short‐term growth inhibition may occur when applying BC without further treatment to temperate soils.