土壤外源钴对大麦根伸长的毒害及其预测模型

选取我国11种不同性质的农田土壤，通过外源添加重金属钴（Co），研究其对大麦（Hordeum vulgare L.）根伸长的毒性阈值及土壤性质对Co毒性的影响。结果发现，Co对大麦根伸长10%抑制效应（EC₁₀）在11种土壤中的变化范围为37.1~3 914 mg·kg^-1土（105.5倍），50%抑制效应（EC₅₀）的变化范围为166.1~6 030 mg·kg^-1土（36.3倍）。建立土壤性质与毒性阈值的回归方程，结果表明土壤pH是影响土壤Co毒性阈值最重要的因子，作为单因子时分别可以解释77.6%、72%的EC₁₀和EC₅₀的变异（P≤0.001）。当在EC₁₀预测模型中引入土壤pH和土壤黏粒（Clay）双因子时，可以解释83.9%的EC₁₀的变异（P<0.001），EC₅₀预测模型中引入土壤pH和总碳（TC）双因子时，可以解释86.1%的EC₅₀的变异（P<0.001）。将我国土壤中得到的Co毒性阈值预测模型和欧洲北美10种土壤的预测模型进行比较验证，结果发现基于我国土壤得到的预测模型可以较为准确地预测欧洲北美土壤中Co的大麦根伸长毒性阈值，但基于欧洲北美土壤的预测模型不能准确预测我国土壤中Co的毒性阈值。研究表明，我国土壤性质对Co毒性有显著的影响，基于土壤性质建立的预测模型可为土壤中Co生态风险评价提供参考依据。     

枫杨幼苗对氟离子的吸收积累规律及毒性效应

【目的】探讨枫杨幼苗对氟污染的修复潜力。【方法】以枫杨当年实生幼苗为研究对象,采用溶液培养的方法,研究不同浓度、不同 pH氟离子胁迫下枫杨幼苗的根、茎、叶的氟含量、转移系数( Tf)、生物富集系数( BCF)的变化以及对枫杨幼苗的植物毒性效应。【结果】1)随着溶液氟离子浓度的升高,枫杨幼苗根、茎、叶的氟积累量逐渐升高,当溶液氟离子浓度为10 mmol·L －1时,枫杨幼苗根、茎、叶的氟积累量最高分别为1604.60,59.41,40.80 mg·kg －1。2)枫杨幼苗体内氟含量的分布存在2种情况：当培养液氟离子浓度为0.5～5 mmol·L －1时表现为根＞叶＞茎,在氟离子浓度为10 mmol·L －1时表现为根＞茎＞叶,转移系数( Tf)介于0.029～0.125之间,可能是过高的氟离子浓度使枫杨幼苗产生了严重的生理胁迫,影响了氟离子从茎向叶的运转。3)随着处理时间的增加,各处理组枫杨幼苗的相对标准蒸腾量均呈下降趋势,溶液氟离子浓度为5,10 mmol·L －1时,对枫杨幼苗蒸腾量变化的影响显著(P＜0.05),对植物的毒性效应很强。4)枫杨幼苗根、茎、叶氟积累量在酸性环境中最大,氟转移能力也最强,在中性环境中表现一般;植物在酸性、中性环境中受到的伤害较大,植物生命活力低,而在碱性条件下时,不仅对枫杨幼苗的伤害小,而且除氟效果较好、持续性强。5)为了达到最佳的处理效果,当废水中氟离子浓度≤2.5 mmol·L －1时,可以选择在酸性条件下利用枫杨来处理;当氟离子浓度为2.5～5 mmol·L －1时,可选择在碱性条件下处理废水。【结论】枫杨幼苗积累氟的能力很强,氟转移能力独特,具有很高的耐氟性,枫杨适合于水体氟污染严重区域的水体净化和植物修复。     

The phytotoxicity of natural tetramic acid derivatives

Natural tetramic acid derivatives have attracted a great deal of interest of chemists because of their structural features and the broad range of biological activities. This paper focuses on five naturally occurring tetramic acid derivatives reported to have phytotoxicity and discusses their common structural characteristics. Copyright © 2011 Society of Chemical Industry     

The Characterization of Heavy Metals in the Grapevine (Vitis vinifera) Cultivar Rkatsiteli and Wild Blackberry (Rubus fruticosus) from East Serbia by ICP-OES and BAFs

Inductively coupled plasma optical emission spectroscopy, in combination with calculation of various biological factors, was used in this study not only for a simple illustration of the present status of some essential and non-essential metals such as copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), arsenic (As), and cadmium (Cd) in the grapevine cultivar Rkatsiteli and wild blackberry from East Serbia but also for the estimation of plant bioaccumulation potentials. Great majority of detected metal concentrations were in normal ranges except in few cases: Zn concentrations were at the level of deficiency in almost all plant parts, and some Cu and As concentrations were at the levels that could be considered phytotoxic. Biological accumulation factors provided very informative data on metal accumulation and translocation in both plants and pointed to low accumulation rates of metals except in the case of Cu, Zn, and As in some wild blackberry tissues.     

A new plant-based bioassay for aquatic sediments

Background, Goal and Scope  To date, standardised bioassays for the assessment of the ecotoxicological potential in sediments and dredged material use test organisms like bacteria, algae and crustaceae. This paper presents the development and application of a novel sediment contact test (whole sediment) withMyriophyllum aquaticum, a representative of rooted aquatic macrophytes. The aim of the present study is to demonstrate the value of a sediment contact test with rooted macrophytes as a supplement to existing test batteries in order to improve the assessment of sediment toxicity. Methods  The newly developed sediment contact test withMyriophylhim aquaticum was applied to natural whole sediments. For performing the test, whorls ofMyriophyllum aquaticum were directly planted in the native sediment and incubated in the light at 24°C (cf. section results and discussion). The end points of the test were the number of the shoots and the fresh weight of the whole plants. The duckweed growth inhibition test withLemna minor according to ISO/DIS 20079 was performed in pore waters from sediment samples. The results of the sediment contact test withMyriophyllum aquaticum were compared with each other and with those of the aquatic duckweed test. Results and Discussion  A test protocol for the new plant-based sediment contact test using the aquatic plantMyriophyllum aquaticum as an indicator was developed. The best control sediment proved to be the OECD sediment (OECD 207). A test period of 10 days appeared to be sufficient for the test. The increase of biomass and the derived growth rate were found to be the most suitable evaluation parameters. The growth behaviour ofMyriophyllum aquaticum differed depending on the origin of sediments. Therefore, plant-affecting contamination, that is bound in sediments, was indicated. Conclusions  The novel sediment contact test withMyriophyllum aquaticum can indicate phytotoxic effects in sediments. Therefore, it allows a better assessment of the overall-toxicity in whole sediments. Recommendations and Outlook  The sediment contact test withMyriophyllum aquaticum is a valuable tool for the evaluation of the ecotoxicological risk potential of waters and sediments. It should become a complement to a standardised test battery generally used for the assessment of sediment toxicity.     

Response of Soil and Plant to Boron-Doped Aluminum Hydroxide

The aims of this work are to test whether boron (B) may alleviate soil acidification and aluminum (Al) phytotoxicity to rape (Brassica napus L.) in acidic soil. The Al hydroxide that reacted with borax was called ad-B-Al hydroxide. Point of zero charge (PZC) of Al hydroxide (pH 4.86) was greater than that of ad-B-Al hydroxide (pH 4.68). Compared with the control, ad-B-Al hydroxide raised the soil pH significantly by 0.10 pH units. Rape was planted in the control soil, the soil treated with Al hydroxide, and the soil treated with ad-B-Al hydroxide. It was found that the B content of the soil and rape seedlings grown on the soil treated with ad-B-Al hydroxide was greater than the others. Biomass production of rape seedlings grown in the soil treated with ad-B-Al hydroxide was significantly increased compared to that in the others. These demonstrated that ad-B-Al hydroxide can be an important source of B for plants and alleviate acidity of acidic soils because it can decrease exchangeable acid and Al toxicity in soil significantly.     

Organic Acid Effects on Nutrient Uptake by Rice

The purpose of this work was to evaluate the responses of 20 rice cultivars to the phytotoxic effects of acetic, propionic, and butyric acids produced in soils under anaerobic conditions. The study was conducted in a hydroponic system, with four levels (0, 3, 6, and 9 mM) of the three organic acids in the ratio of 6:3:1 in a factorial of complete randomized block design with three replications. The evaluated variables were phosphorus (P) and potassium (K) contents. The analysis of variance revealed a significant interaction, and the established regressions showed differences among the genotypes as evaluated for both variables. Four genotypes were classified as tolerant in relation to P content and three genotypes as tolerant in relation to K. The best performance was verified with japonica genotypes and the irrigation-based growing system.     

Excess trace metal effects on cotton: 4. Chromium and lithium in Yolo loam soil

Abstract

Two cultivars of cotton (Gossypium spp) were grown in Yolo loam soil in a glasshouse to determine phytotoxicity effects of Cr and Li and possible interactions with other metals. The Cr at 100 μg/g soil had no adverse effects on either cultivar studied. A Cr increase was not observed in either stems or leaves. Both cultivars tolerated 25 and 50 μg Li/g soil. The 50 μg Li/g soil resulted in leaves of Acala SJ‐2 with 432 μg Li/g leaves and 720 in Giza 45. The 100 μg Li/g soil resulted in 74% and 87% leaf yield reductions in Acala SJ‐2 and Giza 45 respectively. Leaf concentrations of Li respectively were 1950 and 1850 μg/g. Except at the highest level of Li, leaves had higher concentrations of Li than did roots. The Cr and Li resulted in some plant metal interactions.     

Physiological and biochemical effects of boron toxicity in mustard during the seedling stage

A study was conducted to determine the physiological and biochemical effects of boron in seedlings of mustard (Brassica juncea L. var Varuna). For this seeds were sown in petridishes with varying concentrations of boron (0, 0.33, 3.3, 33, 330 mM) in seed germinator. Seed germination and vigor index was found to be decreased and percentage phytotoxicity was increased in seeds with increase in the concentration of boron in germinating solution. There was accumulation of sugars and decreased starch concentration in cotyledons and embryonic axes of growing seedling with increasing boron stress. For the estimation of oxidative damage in cotyledons and embryonic axes of mustard seedlings, hydrogen peroxide (H₂O₂), thiobarbituric acid reactive substances (TBARS), phenols and activities of antioxidative enzymes- polyphenoloxydase (PPO), superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were determined. Boron toxicity caused accumulation of H₂O₂, TBARS and phenols and affected the antioxidative enzyme activity in growing seedling components.