镁、锰、活性炭和石灰及其交互作用对小麦镉吸收的影响

采用盆栽试验,研究了在镉污染土壤上施用石灰、硫酸镁、硫酸锰和活性炭不同用量以及交互作用对小麦生长和吸收重金属镉的影响.研究结果表明,在试验条件下施用适量的硫酸镁、硫酸锰或与石灰配合能明显提高小麦籽粒产量,单施石灰或与活性炭配合施用降低了小麦籽粒产量;与对照(CK)相比,所有处理秸秆产量均下降.施用硫酸镁能显著降低小麦籽粒和秸秆中Cd浓度,且随用量的增加两增大.低量硫酸锰能有效降低小麦籽粒和秸秆中Cd浓度,高量反而增加小麦对Cd的吸收.石灰、活性炭单独施用或配合施用都能明显减少小麦对Cd的吸收,但籽/杆中Cd比却随石灰用量的增加呈明显的上升趋势.叶面喷施硫酸镁对降低小麦吸收镉的效果与土施相当,但叶面喷施硫酸锰却比土施硫酸锰显著降低了小麦籽粒中的镉浓度与吸收量.硫酸镁与硫酸锰,或石灰、硫酸镁和硫酸锰3种物质配合施用,对小麦籽粒镉浓度和吸收量的降低表现出明显的正交互作用,对抑制小麦体内镉从秸秆向籽粒的转移具有显著效果.     

小麦叶面喷施微肥对籽粒中矿物元素的影响分析

在人体和动植物的生长发育过程中,铁(Fe)、锌(Zn)、硒(Se)3种微量元素起着重要的作用。为了提高小麦籽粒中Fe、Zn、Se元素的含量及进一步分析叶面喷施Fe、Zn、Se肥及其组合对籽粒中Fe、Zn、Se以及其他矿物元素含量的影响,并寻求生产上最适宜的叶面喷施组合,采用不同浓度的硫酸亚铁(Fe肥)、硫酸锌(Zn肥)和亚硒酸钠(Se肥)及其组合对小麦品种北京0045(BJ0045)进行叶面喷施处理。结果表明,叶面喷施Fe、Zn、Se肥均能显著提高BJ0045籽粒中Fe、Zn、Se元素的含量;Fe与Se能够相互促进吸收,Zn能够促进Se与Fe的吸收,Se对Zn有抑制作用;不同的叶面喷施组合处理中,Fe/Zn/Se三者混合肥的使用能显著提高籽粒中Fe、Zn、Se元素的含量,同时发现不同的叶面喷施组合的施用对籽粒中Ca、Mg、Cu、Mn、P矿物元素的吸收也有不同的影响。     

叶面肥对玉米籽粒中矿物元素的影响分析

Fe、Zn、Se等矿物元素在动植物以及人体的生长和发育过程中具有重要作用,为了提高玉米籽粒中Fe、Zn、Se的含量,对叶面喷施Fe、Zn、Se肥及其不同组合,探讨其对玉米成熟籽粒中的Fe、Zn、Se以及其它矿物元素含量的影响。使用不同浓度的硫酸亚铁(Fe肥)、硫酸锌(Zn肥)和亚硒酸钠(Se肥)及其不同组合对京科糯2010(JK2010)进行了叶面喷施处理。叶面喷施不同浓度的Fe肥、Zn肥和Se肥均能显著提高JK2010籽粒中Fe、Zn、Se元素的含量;Fe与Zn能够相互促进吸收,Se能够促进Zn的吸收,Fe与Zn对Se的积累有抑制作用;叶面喷施Fe、Zn、Se肥及其组合对玉米籽粒中Ca元素的积累有促进作用;不同的Fe、Zn、Se肥组合方式对籽粒中Cu的积累有不同的影响;总体上看叶面喷施Fe、Zn、Se肥及其组合对玉米籽粒中Mn、Mg、P等元素的积累影响不大。不同的叶面喷施组合处理中,Fe肥、Zn肥和Se肥三者配合使用能极显著的提高籽粒中Fe、Zn、Se元素的含量,为Fe、Zn、Se肥的生产应用提供新的策略,同时也发现Fe、Zn、Se肥的使用对籽粒中几种不同的矿物元素有不同的影响。     

叶面喷施水溶性壳聚糖和硅肥对两种冬油菜镉吸收的影响

为探究硅肥(Si)和水溶性壳聚糖(WSC)对油菜镉(Cd)含量的影响，在河南省济源市某运行中的典型冶炼厂周边中低度Cd污染农田设置田间试验，选用2种规模化种植的冬油菜甘蓝型秦油1号(QY-1)和白菜型三月黄(SYH)为供试植物，研究叶面喷施Si和WSC对2种供试冬油菜生物量、不同部位Cd含量、生物富集系数的影响。结果表明，与对照相比，叶面喷施2种肥均能降低2种油菜籽粒和豆荚对Cd的吸收。叶面喷施Si和WSC后，QY-1籽粒中Cd含量分别下降8.80%～44.01%和15.01%～37.77%;SYH籽粒中Cd含量分别下降20.94%～32.42%和14.33%～28.65%。2种油菜籽粒和豆荚均在喷施2次Si肥的处理下，Cd含量达到最低，喷施一次WSC的处理次之。经叶面肥处理后，与SYH相比，QY-1的生物量更高，Cd富集能力更低，因此，QY-1更适合应用于轻中度Cd污染土壤的安全生产。综上所述，在我国典型冶炼厂周边中低度Cd污染农田采用低富集冬油菜品种结合喷施叶面肥可以初步实现污染土壤的安全利用。     

CO2浓度升高对不同品种水稻镉吸收和根形态的影响

为了探讨CO2浓度升高下不同水稻品种荣优398 (RY)和粤杂889(YZ)吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明:低Cd处理(5、10、20 μmol·L-1)显著增加水稻生物量;当Cd浓度高于50 μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5～200 μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一.     

籽粒低锌与高锌含量基因型水稻锌营养特性的比较

采用溶液培养和放射性同位素技术,比较籽粒低锌含量基因型水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）湘早籼１７与籽粒高锌含量基因型水稻Ｖ５６根系形态及有关生理特性的差异,发现Ｖ５６的根系比湘早籼１７大（根较长,根体积较大,生物量较高）、根冠比值较高及根系吸收锌的Ｋｍ值较低,因而对锌的吸收量较大。这些特性可作为筛选籽粒高锌含量基因型水稻的指标。     

硅素对水稻幼苗镉积累及抗胁迫应答的调节效应

施硅(Si)可以显著缓解镉(Cd)胁迫对水稻生长发育的毒害效应。本研究通过水培分根试验,研究了Si对水稻幼苗Cd积累及胁迫应答的调节效应。结果表明: Cd胁迫下水稻幼苗的生物量显著降低,加Si可以显著缓解Cd对水稻幼苗生长的抑制效应。水稻幼苗对Cd的吸收、转运和积累明显受到Si的影响,单侧根系Cd胁迫下加Si(Si-Cd+Si,Si-Cd)使根系对Cd的滞留系数达83.3%～83.6%,限制了Cd从根向地上部转移。单侧根系Cd胁迫下非胁迫侧加Si(Si-Cd)处理的植株对Cd的吸收和累积明显增加,尤其是根中Cd的积累量较单侧根系Cd胁迫下无Si(CK-Cd)处理增加了48.2%;而单侧根系Cd胁迫下双侧加Si(Si-Cd+Si)处理则显著降低了根和地上部对Cd的吸收,较CK-Cd处理分别降低了36.7%和54.9%。双侧Cd胁迫下单侧加Si(Cd-Cd+Si)则使根和地上部对Cd的吸收量显著减少,较双侧根Cd胁迫(Cd-Cd)处理分别降低了57.8%和46.5%。Cd胁迫下水稻幼苗根中含较高浓度的Si,加Si则使Cd胁迫下根和地上部积累更多的Si。加Si也影响了水稻幼苗对其他金属元素如钙(Ca)、镁(Mg)、锰(Mn)的吸收,Cd-Cd+Si处理显著增加了根系和地上部的Ca、Mg浓度,但Mn浓度的变化则因Cd胁迫程度而表现不同。加Si对Cd胁迫下根系超氧化物歧化酶(SOD)和过氧化物酶(POD)活性有一定的影响,尤其是Si-Cd处理的胁迫侧POD和非胁迫侧SOD活性显著上升,有利于清除Cd胁迫产生的氧自由基。总之,Si对Cd胁迫下水稻幼苗生长、Cd和Si等的吸收及根系的抗氧化反应有一定的调节效应,植株体内较高的Si浓度有利于增强植株对Cd的耐受性。     

Cd、Zn、Pb及其相互作用对烟草、小麦的影响

烟草对Cd、Zn、Pb是一种敏感性作物,Cd、Zn、Pb对烟草的影响比对小安、水稻都大。 Cd、Zn、Pb在烟草各器官中的累积随土壤Cd、Zn、Pb浓度的增高而增大。 Cd、Zn、Pb在烟草各器官中含量的次序为:茎叶>根>籽粒。它们在根中受阻,而较易转移到茎叶和籽粒中。 烟草对Pb的吸收比对Zn和Cd明显地低。Pb仍然是一种低吸收性元素。 土壤Zn增加,减低了烟草对Cd的吸收,而土壤Pb的增加,则促进了烟草对Cd的吸收。     

养分供应量对玫瑰香葡萄矿质元素和水分吸收的影响

为了研究葡萄各生长发育阶段的肥水需求规律,该试验以4年生‘玫瑰香’葡萄为材料,设置改良Hoagland营养液0.5倍、1.0倍、1.5倍3个浓度处理,探讨不同养分供应量对‘玫瑰香’葡萄矿质元素和水分吸收规律的影响。结果表明:(1)‘玫瑰香’葡萄对矿质元素的吸收量随着新梢的生长而快速增加,且均呈先升后降的趋势,各元素吸收量的最大值均出现在果实膨大期至转色期,整个生长期Ca是葡萄吸收量最大的元素,分别约为P、Mg、K和N的1.38倍、4.55倍、1.24倍和1.13倍,其次是N和K,Mg和P的吸收量较小,N、P、K、Ca、Mg的吸收比例为1.1∶0.9∶1∶1.25∶0.26,而微量元素以Fe和B的吸收量较大。(2)各元素吸收量随处理浓度的增加而提高,表现为0.5倍浓度1.0倍浓度1.5倍浓度,且1.0倍浓度处理的果实品质最佳。(3)在适宜营养液浓度下(1.0倍浓度处理),单株葡萄对各种元素的年吸收量分别为N 44.294g、P 34.58g、K 37.743g、Ca 47.728g、Mg 10.801g、Fe 210mg、Mn 46.11mg、B 79.13mg、Zn 23.56mg、Cu 17.104mg和水631.5L。研究认为,生产中‘玫瑰香’葡萄在营养生长期以施氮肥、钙肥为主,配合施用适量镁肥,而在生殖生长期宜增施钾肥,并适量补充施用微量元素,从而达到提高水肥利用率和果实品质的目的。     

氮锌配施对小麦锌转运、分配与累积的影响

通过田间试验,研究不同氮锌肥运筹方式对小麦植株不同器官中锌的转运、分配与累积的影响。结果表明: 不同处理植株器官中锌浓度和锌累积量的差异达显著水平。与N₃(120 kg·hm^-2)相比,N₁(240 kg·hm^-2)和N₂(180 kg·hm^-2)的籽粒锌浓度分别提高22.0%和8.9%;与未施锌(CK)相比,ZnS(土施锌肥)、ZnF(喷施锌肥)和ZnS+ZnF(土施结合喷施锌肥)处理的籽粒锌浓度分别提高15.4%、60.5%和72.8%,籽粒锌累积量分别提高21.3%、82.5%和102.4%。籽粒中锌主要来自花后吸收锌的再分配,在ZnF和ZnS+ZnF处理中的累积贡献率分别为89.9%和100.0%,锌肥回收率分别较ZnS提高4.8和1.1倍,锌肥利用率分别提高7.9和2.2倍。当前生产条件下,当施氮量<240 kg·hm^-2时,小麦不同器官锌浓度和锌累积量均随施氮量的增加而提高,喷施锌肥可显著提高籽粒中的锌浓度和锌累积量。因而,生产中可通过维持高产施氮方案并结合生育后期喷施锌肥的措施来提高籽粒中的锌浓度和锌累积量,从而提高小麦籽粒锌营养品质。     

Effect of exchangeable sodium percentage and presubmergence on yield and nutrition of rice under field conditions

Summary The effects of exchangeable sodium percentage (ESP) levels of 82, 72, 65 and 35 and 0, 15 and 30 days of presubmergence (submergence prior to the transplanting of rice) on yield and chemical composition of rice and availability of Fe, Mn, Zn and P in soil were studied factorially in a field experiment. Presubmergence increased rice yields at all ESP levels, the effect being more pronounced at high ESP's. Increasing ESP decreased yields and the contents of Ca, Mg, K, Fe, Mn, Zn and Cu but increased that of P and Na in the crop. Presubmergence enhanced absorption of all the above elements by the crop except P, K, Mg, Zn and Cu in the grain and decreased Na in grain and straw. Growing of rice under submerged conditions also facilitated the improvement of these soils. Effects of submergence and ESP on the availability of Fe, Mn, Zn and P in soil and their role in the nutrition of rice are discussed. The results suggest that 15 to 30 days presubmergence improved rice yields on a calcareous sodic soil of the Indo-Gangetic alluvial plain.     

A Dual Role of Se on Cd Toxicity: Evidences from the Uptake of Cd and Some Essential Elements and the Growth Responses in Paddy Rice

This study was carried out to investigate the effects of selenium (Se) on the uptake and translocation of cadmium (Cd) and essential elements in paddy rice (Oryza sativa L., Shuangyou 998). Selenium could alleviate/aggravate Cd toxicity in paddy rice, which depended on the dosages of Se and/or Cd. When Cd treatment level was as low as 35.6 μM, ≤12.7 μM Se could inhibit the uptake of Cd in paddy rice and increase the biomass of paddy rice; however, with Cd levels reaching 89–178 μM, the addition of Se resulted in increases in Cd uptake and exacerbated the growth of paddy rice. Cd always inhibited the uptake of Se. Cd alone suppressed the uptake of Ca, Mg, Mn, Cu, and Zn; however, Se reversed the decreases in the concentrations of the said elements, suggesting an element regulation mechanism to relieve Cd toxicity. Without Cd in the solution, low doses of Se increased the biomasses of shoots and roots at the expense of the more or less decreases in the concentrations of Ca, Mg, K, Fe, Mn, Cu, and shoot Zn, indicating an antagonistic effect of Se on these cations. The presence of Cd could also reverse these decreases especially at the highest treatment levels for both Se and Cd, also suggesting an element regulation mechanism responsible for the detoxification of high dosages of Se. Consequently, when Se is used to alleviate Cd toxicity, attention must be paid to the Cd pollution extent and doses of Se supplement.     

Effects of Soil Properties on the Transfer of Cadmium from Soil to Wheat in the Yangtze River Delta Region, China—a Typical Industry–Agriculture Transition Area

In order to identify the effects of soil properties on the transfer of Cd from soil to wheat under actual field conditions, 126 pairs of topsoil and wheat samples were collected from the Yangtze River delta region, China. Relevant parameters (Cd, Ca, Mg, Fe, Mn, Zn, N, P, K, S, pH, total organic carbon, and speciation of soil Cd) in soil and wheat tissues were analyzed, and the results were treated by statistical methods. Soil samples (19.8%) and 14.3% of the wheat grain samples exceeded the relevant maximum permissible Cd concentrations in China for agricultural soil and wheat grain, respectively. The major speciations of Cd in soil were exchangeable, bound to carbonates and fulvic and humic acid fraction, and they were readily affected by soil pH, total Ca, Mg, S and P, DTPA-Fe, Ex-Ca, and Ex-Mg. Cadmium showed a strong correlation with Fe, S, and P present in the grain and the soil, whereas there was no significant correlation in the straw or root. Generally, soil pH, Ca, Mg, Mn, P, and slowly available K restricted Cd transfer from soil to wheat, whereas soil S, N, Zn, DTPA-Fe, and total organic carbon enhance Cd uptake by wheat.     

Evaluation of Organic and Inorganic Amendments on Maize Growth and Uptake of Cd and Zn from Contaminated Paddy Soils

Pot and field experiments were conducted to investigate the effects of soil amendments (cow manure, rice straw, zeolite, dicalcium phosphate) on the growth and metal uptake (Cd, Zn) of maize (Zea mays) grown in Cd/Zn contaminated soil. The addition of cow manure and rice straw significantly increased the dry biomass, shoot and root length, and grain yield of maize when compared with the control. In pot study, cow manure, rice straw, and dicalcium phosphate all proved effective in reducing Cd and Zn concentrations in shoots and roots. Cd and Zn concentrations in the grains of maize grown in field study plots with cow manure and dicalcium phosphate amendments to highly contaminated soil (Cd 36.5 mg kg^?1 and Zn 1520.8 mg kg^?1) conformed to acceptable standards for animal feed. Additionally both cow manure and dicalcium phosphate amendments resulted in the significant decrease of Cd and Zn concentrations in shoots of maize.     

不同有机肥对土壤镉锌生物有效性的影响

在南方典型稻田设置连续4年施用猪粪、鸡粪、稻草的定位试验,监测施用不同有机肥条件下土壤及水稻植株镉(Cd)、锌(Zn)含量的变化,研究有机肥对土壤Cd、Zn活性及其交互作用的影响.结果表明: 施用有机肥(猪粪、鸡粪、稻草)对土壤全Cd、有效态Cd含量及Cd活性皆无显著影响,但有增加土壤Cd全量的趋势,且显著增加土壤全Zn、有效态Zn含量及Zn活性.施用猪粪、鸡粪、稻草皆可降低稻米Cd含量,降Cd效果为猪粪>鸡粪>稻草,猪粪处理水稻稻米、茎、叶Cd含量分别比对照下降37.5%、44.0%、36.4%;鸡粪处理水稻米、茎、叶Cd含量分别比对照下降22.5%、33.8%、22.7%;而稻草处理水稻米Cd含量比对照下降7.5%,但茎、叶Cd含量比对照分别增加8.2%、22.7%;施用猪粪、鸡粪降低稻米Cd含量主要是降低了水稻植株对土壤Cd的富集,而施用稻草则主要是降低了水稻茎Cd向稻米的转运.施用有机肥还增加了水稻茎Zn含量,施用猪粪、鸡粪、稻草的水稻茎Zn含量比单施化肥分别增加53.4%、41.2%、13.9%,但对水稻稻米、叶Zn含量无显著影响.Zn、Cd在土壤、植株茎中皆表现出显著的拮抗作用,土壤及水稻茎Zn含量的增加显著抑制了水稻米、茎、叶对Cd的吸收积累,且随土壤有效态Zn/Cd含量比值的增加,Zn、Cd竞争土壤吸附不是抑制水稻吸收积累Cd的主控因子,而Zn、Cd竞争吸收才是影响水稻吸收积累Cd的主控因子.     

Cadmium effects on mineral nutrition of the Cd-hyperaccumulator Pfaffia glomerata

A plant’s ability to survive in a stressful environment is correlated with its nutritional status, which can be affected by cadmium (Cd) uptake. The present study evaluated the influence of Cd on the concentrations and distributions of nutrients in the roots and shoots of the Cd-hyperaccumulator Pfaffia glomerata (Sprengel) Pedersen. Plantlets were cultivated in nutrient solutions containing increasing Cd concentrations during 20 days under greenhouse conditions, and the concentrations of Cd and essential macro- (N, P, K, Ca, Mg and S) and micro- (Zn, Fe, Mn, Cu) elements in the roots and shoots were subsequently determined. Cd did not affect the plant biomass production. Cd accumulation was found to be higher in roots than in shoots, and influenced the distribution of macro and micro elements in those plants. Despite the high phytotoxicity of this element, our results indicated the existence of Cd-tolerance mechanisms in both nutrient uptake and distribution processes that enabled these plants to survive in Cd-contaminated sites.     

Contribution of mineral nutrients from source to sink organs in rice under different nitrogen fertilization

The pot experiment with three treatments of nitrogen (N) topdressing was performed with the japonica rice cultivar viz. Huaidao 5. Remobilization of nine mineral nutrients including N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) was measured from the source organs including bracts, leaf, and sheath to sink rice grain. Experimental results showed considerable contribution of bracts to grain for N, Mg, and Zn, with the averages contributions of 5.96, 12.56, and 12.34%, respectively, indicating a positive role of rice bracts in N, Mg, and Zn remobilization during grain filling. By contrast, minor contribution of bracts to grain P, K, and Cu was revealed, with the contribution rate being 0.99, 3.90, and 3.05%, respectively. Further, a net increase in Ca and Fe concentrations of bracts was detected, implying that bracts function as a sink of these mineral nutrients. In addition, grains produced at a moderate level of N topdressing had higher Fe and similar Zn concentration in comparison with those at high N level, suggesting the possibility of N management for maintaining Fe and Zn level under high yielding conditions.     

Ca在水稻籽粒中的富集及其与其它7种元素的关系

通过环境扫描电镜结合X射线电子探针显微分析技术,对21种不同基因型的水稻籽粒颖壳内、外表面以及颖果表面、糊粉层、近糊粉层和米中部的Ca含量进行测定。结果表明,Ca元素在水稻籽粒不同部位的含量有明显差异,颖壳内外表面和颖果表面Ca含量较高,近糊粉层和颖果中部含量较低,在颖果中Ca主要富集在糊粉层中;而且不同基因型水稻籽粒同一部位或不同部位Ca的积累量也有较大差异,这可能是由遗传差异引起的。糊粉层中的Ca含量影响着颖壳外表面、颖果表面、近糊粉层和米中部的Ca含量。另外,籽粒不同部位Ca含量与P、Mg、K、Si、Al、Cd含量之间存在显著或极显著的非线性关系,与Pb含量之间不存在显著的非线性关系。说明Ca在水稻籽粒中富集的同时也影响着P、Mg、K、Si、M、Cd等元素的富集。