酚类化合物短期暴露对小麦和大麦苗期根伸长的影响

采用小麦和大麦为受试作物,以其在受试化合物污染的土壤中培育3 d后获得的根伸长的半数抑制浓度(IC50)评价了12种酚类化合物的毒性效应。结果表明,在所设浓度范围内,酚类对作物根伸长均存在剂量-效应关系。小麦对受试酚类的IC50范围为:12.92~231.76 mg·kg-1,其中邻苯二酚只在最高浓度500 mg·kg-1时对小麦的毒性效应显著。大麦对受试化合物的IC50范围为:7.15~478.31 mg·kg-1。小麦对3-甲基酚、双酚A、2-萘酚和壬基酚相对敏感,而其它8种化合物则是大麦相对更敏感。酚类化合物对小麦和大麦的毒性强度整体趋势一致。     

2个镉耐性差异箭舌豌豆品种中镉的化学形态及亚细胞分布

通过溶液培养实验,研究了镉胁迫下2个箭舌豌豆(Vicia sativa)品种(镉耐性品种L3,镉敏感品种ZM)中镉的积累、镉的亚细胞分布和化学形态以及非蛋白巯基化合物(NPTs)的响应。结果表明2个箭舌豌豆品种根较地上部积累更多的镉。镉在箭舌豌豆根、茎和叶中主要分布于可溶性组分,敏感品种ZM根中可溶性组分的镉含量和占总镉的比例显著高于耐性品种L3。细胞壁结合镉占总镉的比例在2个品种中均为叶>茎>根。镉在箭舌豌豆根和茎内主要以去离子水(d-H2O)提取态和1 mol·L-1氯化钠(Na Cl)提取态存在,ZM根中d-H2O提取态镉的含量和比例显著大于L3。箭舌豌豆叶中镉主要以2%醋酸(HAc)提取态存在。ZM叶中80%乙醇提取态镉的比例大于L3,0.6 mol·L-1盐酸(HCl)提取态镉和残渣态镉的比例小于L3。2个品种根和茎中NPTs的含量在镉胁迫下显著升高,ZM根中NPTs的含量显著大于L3。研究结果表明,箭舌豌豆镉解毒的主要机制包括限制镉由根部向地上部转运和液泡隔离。此外,根和茎中镉与有机酸结合和NPTs螯合,叶中镉以移动性低、毒性低的形态存在也是箭舌豌豆镉解毒的重要机制。ZM较L3根中更多镉以移动性高的形态存在,L3较ZM叶中更多镉以难移动的形态存在,是L3较ZM具有更高镉耐性的重要原因。     

Soil pH and Anion Abundance Affects on Copper Adsorption

Abstract

Copper (Cu) input to agricultural soils results from Cu containing pesticides and/or that in soil amendments, such as manure or sewage sludge. Soil and soil solution properties influence the adsorption and desorption of Cu by the soil, which in turn determines its plant availability and/or phytotoxicities. Effects of different anion enrichment in the equilibrium solution on Cu adsorption by different soils (pH range of 6.2–9.9) were investigated in this study over a range of Cu concentrations. With Cu concentrations in the range of 0–100 mg L^?1 in the equilibration solution, 95–99% of applied Cu was adsorbed by all three soils. The adsorption of Cu was similar regardless of using either 0.01 M CaCl₂ or Ca(NO₃)₂ as the equilibration solution. When the Cu concentration in the equilibration solution was further increased in the range of 500–2000 mg L^?1, the adsorption of Cu decreased from 60 to 24% of applied Cu in two soils with pH 6.2–7.9. In a high pH soil (pH = 9.9), the Cu adsorption decreased from 77 to 34%. Addition of incinerated sewage sludge (ISS) to a Palouse silt loam soil (pH = 6.2) increased the Cu adsorption as compared to that by unamended soil. This was, in part, due to an increase in the soil suspension pH with ISS amendment.     

Chitosan/glyphosate formulation as a potential,environmental friendly herbicide with prolonged activity

Although there are many reports on the dangers posed by glyphosate, this herbicide is still one of the most popular and widely used total weed killers. Therefore, great effort should be made to minimize exposure to this herbicide and limit its losses into the environment. The aim of this study was to prepare a new formulation consisted of various molecular weight chitosans with glyphosate and their evaluation toward active substance release, phytotoxicity, and preliminary herbicidal efficiency. The phytotoxicity study of the obtained chitosan/glyphosate formulations was determined based on the Organisation for Economic Co-operation and Development 208 guideline. Among all tested formulations evaluated for phytotoxicity, that containing the highest molecular weight of chitosan was found to be the least toxic, showing simultaneously the most effective herbicidal activity against selected weeds. The release rate of glyphosate from the obtained formulations was dependent on the molecular weight and viscosity of chitosan.     

不同堆肥方式对鸡粪与秸秆混合堆肥效果

以鸡粪和玉米秸秆为堆肥原材料，进行了露天堆肥和反应器堆肥对比实验。结果表明，反应器堆肥（堆体P2）较露天堆肥（堆体P1）升温快，堆体P2达到了《粪便无害化卫生标准（GB7959—87）》的要求，堆体P1未达到；在整个堆肥过程中，堆体P1的水分总损失量（26．5％）大于堆体P2的水分总损失量（20．6％）；堆体P1和P2的有机质降解主要发生在堆肥前期0～21d，分别完成了81．4％和84．5％的有机质降解量；堆体P1和P2的C／N比在堆肥过程中均呈下降趋势，最终C／N比分别为18．3和14．8；种子发芽指数GI_P1〈GI_P2，表明采用堆体P2的堆肥产品的植物毒性较堆体P1更小。各指标实测数据表明，反应器堆肥的堆肥产品的稳定性和腐熟程度较露天堆肥更好。     

自然光和UV辐照下二级出水DOM及毒性的变化

为了探明自然光和紫外光（UV）对二级处理出水中溶解性有机物（DOM）及其毒性效应的削减特性，研究了在自然光和UV两种不同光源的辐照条件下，二级处理出水中DOM的光谱特性、遗传毒性和植物毒性变化，阐明了毒性效应变化的成因.结果表明：相比于自然光照，UV辐照可以明显降低二级处理出水的UV₂₅₄，并达到21%矿化.自然光和UV均可降低二级处理出水中有色溶解性有机物（CDOM），但去除的组分有所差异.同时，自然光照与UV辐照均可降低二级处理出水的遗传毒性，其削减率分别达到92%和61%.遗传毒性的变化与CDOM荧光强度变化有显著相关性.UV辐照可降低二级处理出水的植物毒性，削减率达到81%，而自然光照对二级处理出水植物毒性的削减率仅为19%，削减效果较差.利用UPLC-MS检测二级出水中的除草剂，发现植物毒性削减的差异主要是由于自然光照下二级处理出水中的阿特拉津降解缓慢，表观降解速率常数为0.0033h^-1；但是UV辐照下二级处理出水中的阿特拉津可快速降解，其表观速率常数为0.2225h^-1.这为污水厂排放水毒性效应控制及生态安全保障提供了一定的依据.     

人工合成纳米TiO_2和MWCNTs对玉米生长及其抗氧化系统的影响

通过营养液培养试验,研究了纳米金红石相TiO2和多壁碳纳米管(multiwalled carbon nanotubes,MWCNTs)2种人工合成纳米材料悬浮液对玉米幼苗生物量、根系形态、抗氧化酶活性和脂质过氧化的影响.结果表明,在纳米材料悬浮液培养9d后,纳米金红石相TiO2对玉米生长有显著抑制作用(p0.05),50、100、200 mg/L浓度处理的植株根系干物质量分别比对照低40.31%、48.06%、62.02%;而MWCNTs对植物生长的抑制不明显.在2种纳米材料处理下,植物组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和过氧化物酶(POD)活性均显著升高(p0.05).纳米金红石相TiO2处理使玉米植株体内脂质过氧化产物MDA含量增多,而MWCNTs处理下MDA含量减少但无显著性变化.说明纳米金红石相TiO2的植物毒性比MWCNTs大,2种纳米材料都能引起植株产生氧化应激,仅纳米TiO2造成氧化损伤,这可能与2种纳米材料的化学组成和形状不同有关.     

Phytotoxicity of four herbicides on Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii

The physiological effects of 4 herbicides (butachlor, quinclorac, bensulfuron-methyl and atrazine) on 3 submerged macrophytes (Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii) were tested in laboratory conditions. The variables of the relative growth rate and the photosynthetic pigments content showed that all of the tested herbicides affected the growth of the plants obviously. The abnormal growth of the plants was observed in most treatment groups, even at the lowest concentration (0.0001 mg/L). Except for the C. demersum treated with quinclorac at 0.005 and 0.01 mg/L, the relative growth rates of the plants were inhibited significantly (p < 0.05). Statistical analysis of Chl-a content was carried out with both the t-test and one-way ANOVA to determine the difference between the treatment groups and control. The results showed that Chl-a contents of the plants in all treatment groups were affected by herbicides significantly, except for the C. demersum treated with bensulfuron-methyl at 0.0005 mg/L. The decrease content in Chl-a was positively correlated to the dosage of the herbicides in most treatment groups. It was suggested that herbicides in water body might potentially affect the growth of aquatic macrophytes. Since the Chl-a content of submerged macrophytes responded to the stress of herbicides sensitively and directly, it could be used as biomaker in environmental monitoring or in the ecological risk assessment of herbicide contamination.     

对比研究槽式堆肥处理不同畜禽粪便对植物毒性的影响

为揭示槽式堆肥过程中不同畜禽粪便堆肥理化性质的变化及其对植物毒性的影响,分别开展了以羊、牛、鸡、猪粪便与木屑为堆料、为期44 d的好氧槽式堆肥对比试验,采集了不同堆肥期的堆肥样品,测定了堆肥的pH、电导率（EC）、可溶性有机碳（DOC）、硝氮（NO₃^--N）、氨氮（NH₄⁺-N）、全氮（TN）、碳氮比（C/N）、全磷（TP）、全钾（TK）、铜（Cu）、锌（Zn）含量及水堇的相对生长指数（RGI）和种子发芽指数（GI）,并通过相关分析和线性回归拟合,分析了堆肥过程粪便对水堇种子植物毒性的影响机制.结果表明,槽式堆肥过程中,羊粪的高温期持续时间最长,牛粪其次,猪粪和鸡粪最短;堆肥结束时4种粪便均呈弱碱性.堆肥过程中猪粪和鸡粪的EC降低,其他粪便的EC变化幅度较小,各粪便的DOC、NH₄⁺-N含量降低,NO₃^--N、TP、TK、Cu和Zn含量增加,牛粪和鸡粪的C/N逐渐降低,而猪粪和羊粪的C/N呈先升后降的趋势,羊粪和猪粪的TN含量下降,鸡粪和牛粪的TN含量缓慢上升.堆肥过程中4种粪便对水堇种子的植物毒性均降低,且RGI和GI升幅由高到低为：牛粪 > 羊粪 > 鸡粪 > 猪粪.相关分析表明,堆肥过程中羊粪的TP、Cu、Zn,牛粪的Zn、TK、TP、NO₃^--N,鸡粪的NO₃^--N、TN、Cu,猪粪的NO₃^--N、TP、Zn、TK与RGI呈显著正相关（p<0.01）;而羊粪的Cu、TP、TK,牛粪的Zn、TK、TP,鸡粪的Cu、TN、NO₃^--N、TK,猪粪的TP、Zn、NO₃^--N与GI呈显著正相关（p<0.01）.由此表明,不同粪便堆肥的以上指标促进了植物的根伸长和种子发芽.但堆肥过程中羊粪的NH₄⁺-N、TN、DOC,牛粪的NH₄⁺-N、DOC、C/N、EC,鸡粪的C/N、EC、DOC,猪粪的NH₄⁺-N、DOC、EC与RGI呈显著负相关（p<0.01）;羊粪的NH₄⁺-N、TN、DOC,牛粪的NH₄⁺-N、DOC、C/N,鸡粪EC、DOC、C/N,猪粪的NH₄⁺-N、DOC、EC与GI呈显著负相关（p<0.01）.由此表明,不同粪便的以上指标显著抑制了植物的根伸长和种子发芽.多元回归分析说明,堆肥过程羊粪和牛粪的NH₄⁺-N,鸡粪的NO₃^--N、Cu、C/N和EC,猪粪的NO₃^--N和TK对水堇种子根伸长具有显著的影响,而羊粪的NH₄⁺-N和TK,牛粪的DOC、pH和EC,鸡粪Cu、TN和NO₃^--N,猪粪的TK对水堇种子发芽具有显著的影响.以上对比研究结果可为不同畜禽粪便槽式堆肥处理和土地利用提供重要的理论依据和决策支持.     

Evaluation of air pollution phytotoxicity downwind of a phosphate fertilizer factory in India

The effects of air pollution on plants downwind of a fertilizer factory at Udaipur, India, were studied using three woody perennials. Seedlings of these species including a shrub (Carissa carandas L.), a leguminous avenue tree (Cassia fistula L.) and a fruit tree (Psidium guajava L.) were grown in earthen pots at different study sites receiving varying levels of air pollution input. Changes in plant growth, morphological characteristics, photosynthetic pigment, ascorbic acid, N and S contents and in dry matter allocation were considered in relation to the status of ambient air quality. Observations with these parameters have indicated that the ambient air around the factory contained pollutants at phytotoxic levels. Plant height, basal diameter, conopy area, leaf area and chlorophyll, ascorbic acid and foliar-N concentrations decreased with increasing pollution load. However, foliar-S increased slightly at polluted sites. Air pollution load around the factory have also altered the biomass allocation. Root:shoot ratios increased in C. fistula and P. guajava at polluted sites. In contrast, for C. carandas the above ground parts, where foliage assumed predominance showed precedence over the root growth. This species responded characteristically to air pollution stress by allocating more of its photosynthate towards leaf production and shoot growth.