粮食作物锌的吸收运转分配和改善子粒锌含量的理论与技术途径

基于前人取得的主要成果，系统分析了从土壤锌有效性到锌在子粒部位的积累主要过程及其控制点，从三方面：1）植株对锌的吸收过程；2）锌在地上部各营养器官间的运转分配过程；3）锌从营养器官向子粒部位的运转过程，总结并提出今后应利用作物锌高效性的种质资源特点，通过传统育种与生物技术方法选育出锌高效积累型品种和合理配套的栽培技术等农艺措施，提高作物子粒锌的含量。     

Beneficial effects of earthworms and arbuscular mycorrhizal fungi on establishment of leguminous trees on Pb/Zn mine tailings

Planting trees to stabilize metalliferous mine tailings is a widely used form of land reclamation although substantial soil amendment is invariably required, both to improve the physico-chemical status of the tailings and to ameliorate toxicity prior to planting. Here, we report a glasshouse study of the combined effects of burrowing earthworms (Pheretima guillelmi) and arbuscular mycorrhizal fungi (Glomus spp., AMF) on establishment of a naturally invasive, woody, nitrogen-fixing legume, Leucaena leucocephala, on topsoil-amended Pb/Zn mine tailings. AMF provided the most effective preliminary inoculant, improving N, P and K uptake, but earthworms had more influence improving N nutrition. In most cases, the combined effects of AMF and earthworms were additive and proved to be beneficial to plant growth, plant nutrition and for protection against uptake of toxic metals. AMF influenced metal uptake more than earthworms, but together they reduced mobility of Pb and Zn in soil by as much as 25%. Some minor but significant negative interactions were also evident; for example, earthworms enhanced soil microbial activity but inhibited the beneficial effects of AMF on N₂-fixation. We argue that increased attention to ecological interactions in soil could reduce costs and improve the efficacy of restoring a vegetation cover to land impacted by contaminated spoils.     

Comparison of Ni/Zn Accumulation Ability of Thlaspi japonicum from Three Different Areas in Hokkaido

Thlaspi japonicum is a Japanese Ni-hyperaccumulator plant growing in areas with serpentine soil containing a high level of Ni. In the present study, we investigated the ability of wild Thlaspi japonicum plants inhabiting non-ultramafic soil areas of Hokkaido to accumulate Ni/Zn. Wild T. japonicum plants growing on Rebun Island (Rebun-T) accumulated small amounts of Ni, while the plants cultivated on ultramafic rock soil accumulated large amounts of Ni, like T. japonicum growing on Mt. Yubari (Yubari-T), and this change was also observed for T. japonicum growing on Mt. Tengu (Tengu-T). All the T. japonicum plants transplanted on both ultramaflc soil or Andosol accumulated over 100 mg kg⁻¹ Zn, especially the Ni/Zn content of Tengu-T plants tended to be higher than that of the plants growing in the other two areas. In contrast, transplanting of Yubari-T plants from ultramafic soil with a high level of Ni to soil with a lower-Ni content decrease of the Ni concentration in the leaves. Wild Rebun-T plants showed a smaller biomass than the Yubari-T and Tengu-T plants, and some individuals of the Rebun-T population were smaller than those of the other populations, with tiny radical leaves. Zinc content of the small leaves was not significantly different from that in large leaves. These results suggested that T. japonicum plants are able to accumulate high Ni/Zn accumulation, regardless ecotype, habitat and leaf size.     

Effect of high rates of zinc on several crops grown on an irrigated plainfield sand

Abstract

A field experiment was conducted to determine whether Zn applied for pathogen control could accumulate to a level which would be toxic to snapbeans, cucumbers, or corn. Zinc sulfate (ZnSO₄) was applied at rates varying from 0 to 363 kg Zn/ha on a Flainfield loamy sand to approximate 3, 9, 27 and 81 years of fungicidal treatment.

Even at the high rate of Zn, yields of snapbeans, cucumbers, or corn generally were not reduced. As rates of applied Zn increased, there was a corresponding increase in the level of Zn in the leaf tissue of all crops grown. At the high Zn rate, snapbean and cucumber leaf tissue accumulated over 350 ppm Zn. Available soil Zn was extracted with 0.1N HCl, EDTA, or DTPA. Highly significant correlations were observed between the Zn removed by each extractant and plant tissue Zn, thus, indicating that the various extractants were equally effective in predicting Zn uptake.

Very little downward movement of Zn was observed. Two and one‐half years after application, the Zn had leached to a depth of only 30 cm in the soil profile at the higher Zn rates.

These data indicate that application of Zn‐containing fungicides and bactericides should not cause a Zn toxicity problem on the Plainfield sand in the foreseeable future.     

Effect of zinc levels on phosphorous and zinc content in sand‐cultured soybeans

Soybeans (Glvcine max L.) cv. “Clark”; were grown in the greenhouse in sand‐filled plastic pots sub‐irrigated with Hoagland No. 1 solution to determine the possible inhibitory effects of Zn on the uptake of P. Zinc rates used were 0.05 (control), 0.25, 0.5 and 2.5 ppm. Yields equalled the control at Zn levels of 0.25 and 0.5 ppm, but plants grown in solutions containing 2.5 ppm Zn were stunted severely. Foliar Zn and P levels differed very little among Zn treatments. Zinc levels were highest and P levels were lowest, however, in the roots and stems of soybeans grown in solutions of 2.5 ppm Zn. Zinc and P uptake was significantly inhibited in the leaves, stems and roots of plants grown at the highest Zn rate. The recycling of wastes containing high Zn content could adversely affect plant growth by a suspected antagonism with P.     

NYH-1型~(14)C核素高灵敏探测装置

本文描述了可测量低活度1 4 C核素的高灵敏探测装置。在FH 36 7探头的基础上进行了改装 ,更换了闪烁介质 ,增加了物质屏蔽和反符合屏蔽以及相应的电子线路。本装置对1 4 C的探测效率 ,植物干样为 6 93% ,土壤样为 3 2 % ,装置的本底计数为 2 35cpm     

Combined Effect of Zinc and Cadmium Levels on Root Antioxidative Responses in Three Different Zinc‐Efficient Wheat Genotypes

This work was undertaken to investigate the effect of zinc (Zn) nutrition on root antioxidative responses to cadmium (Cd) toxicity of three wheat genotypes differing in Zn efficiency. A hydroponic experiment was carried out in which two bread wheat genotypes (Triticum aestivum L. cvs. ‘Rushan’ and ‘Cross’) and one durum wheat genotype (Triticum durum L. cv. Durum) were exposed to three Zn²⁺ (10^?11.11, 10^?9.11 and 10^?8.81 μm ) and two Cd²⁺ (10^?11.21 and 10^?10.2 μm ) activity levels. ‘Durum’ showed the highest root sulfhydryl (‐SH) groups content and activity of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) and the lowest root membrane permeability among the studied wheat genotypes. In ‘Durum’, Zn nutrition increased root ‐SH groups concentration of seedlings in Cd‐free nutrient solution. In ‘Cross’, as Zn²⁺ activity increased from 10^?11.11 to 10^?9.11 μm , root ‐SH groups concentration was increased while decreased with increasing Zn²⁺ to 10^?8.81 μm . Cadmium increased root membrane permeability at both 10^?11.11 and 10^?9.11 μm Zn²⁺ levels. Activity of CAT and APX increased in roots of ‘Durum’ plants exposed to Cd at Zn²⁺ = 10^?9.11 μm and thereafter decreased with increasing Zn²⁺ activity. In contrast, CAT and APX activity in roots of ‘Cross’ and ‘Rushan’ genotypes exposed to Cd decreased by increasing Zn activity to 10^?9.11 μm and then increased at Zn²⁺ = 10^?8.81μm . The results showed an increase in activities of antioxidative enzymes in Cd‐treated plants, although this increase was dependent on the crop genotype and Zn levels in the media.     

1989—2010年广东沿海牡蛎体内锌的时空分布特征与污染水平分析

根据历史和调查资料,对1989—2010年广东沿海牡蛎体内锌(Zn)的时空分布特征和污染水平进行了分析与比较。结果表明,牡蛎体内Zn的浓度总平均值为211.5 mg/kg,从总体看其浓度出现频率呈对数正态分布。在时间上,牡蛎体内Zn总体平均浓度的分布呈阶段性变化,具体表现为1989—2007年Zn的浓度呈微弱降低的趋势,基本维持在197.0 mg/kg的水平;2007—2009年牡蛎体内Zn的浓度有明显升高的趋势,之后Zn的浓度有所降低。在空间上,粤东和粤西沿海牡蛎体内Zn浓度的变化均呈先降低后增加的趋势,且基本与广东沿海牡蛎体Zn平均浓度的变化趋势相同,而珠江口牡蛎体Zn的浓度水平相对较高并表现出趋于稳定的变化规律。单因子指数和非致癌性风险指数评价结果均表明,牡蛎体内Zn的总体不存在明显的污染,但从当前保护环境角度应当尽快设立我国水产品中Zn含量的限定标准。     

杨树吸收富集矿山流域污染土壤重金属的研究

为探究杨树修复矿山流域重金属污染土壤的性能,选取安徽省铜陵市某矿山流域,对其中8个采样点内人工林美洲黑杨（Populus deltoides W. Bar-tram ex Marshall）和立地土壤进行取样,测定了土壤和杨树不同部位Cd、Zn、Cu、Pb和As的含量。参考农用地土地管控标准(GB15618—2018)可知,所有采样点土壤中Cd和Pb的含量均超过农用地风险筛选值;矿山和流域下游土壤中Cd、Pb和As的含量超过农用地土壤风险管控值,Zn和Cu的含量超过农用地风险筛选值。杨树在重金属不同污染程度上的立地土壤中均生长良好,表现出较强的耐受性。从8个样点重金属的平均富集系数（BCF）和转运系数（TF）来看,杨树对Cd的富集转运能力最强,平均BCF达到5.5,平均TF达到1.83,不同部位中树叶富集转运能力相对最强而树枝和树干最弱;对于其他重金属,除树叶Zn的平均BCF达到1.63外,杨树不同部位Pb、As、Zn和Cu的平均BCF均小于1,其中Pb和As的平均BCF均小于0.01,表现出极差的富集能力;杨树对Pb的平均TF小于1,对As、Zn和Cu的平均TF均大于1,在低富集能力水平下表现出较好的转运能力。因此,杨树可作为以Cd-Zn为主的重金属污染土壤的修复树种。     

Influence of Dissolved Organic Carbon and Initial Moisture on Zinc Sorption by Two Arid Soils

Sorption of added zinc to irrigated soils in arid regions is an important process that may control the availability of zinc to growing plants . Two soil surface samples varying in clay , organic matter , and calcium carbonate content were selected from central and southwestern regions of Saudi Arabia and prepared in order to give different initial moisture contents ranging from air dried to 100 % of field capacity . The sorption experiment was conducted using Zn concentrations ranging from 5 to 25 mg L 1, prepared from ZnSO4 either in distilled water or in solutions containing 75 mg L 1 dissolved organic carbon (DOC). Results indicate that the amount of Zn sorbed in the presence of DOC was relatively high compared with the absence of DOC and Zn retention was strongly affected by the initial soil moisture content . Also , equilibrium Zn concentrations were quite low , while Zn retentions were high in all treatments . Data of Zn sorption were described by the Freundlich isotherm , and two linear portions were found in most cases . In the absence of DOC , retentions of added Zn were controlled by the available exchange sites and / or the precipitation of Zn as sparingly soluble forms. Zn ions in the presence of DOC were able to form soluble - Zn organic complexes that adsorb on the soil surfaces . The extent of such behavior was related to the variations in clay , organic matter , and calcium carbonate contents as well as the initial moisture of the soil . Results indicate that addition of DOC reduces the amount of extractable Zn from either soil Zn or the sorbed Zn by ammonium bicarbonate diethylenetriamine pentaacetic acid ( AB DTPA ). More than 80 % of the sorbed Zn was extracted by AB-DTPA , and the percentage of extracted / sorbed Zn decreased with the increase in sorbed Zn . The obtained results give evidence that initial moisture content and addition of DOC reduce the extractability of applied inorganic Zn by AB-DTPA extract in arid soils.