昆明地区珍稀濒危植物及其保护对策

对昆明地区分布的珍稀濒危植物的种类、分布、保护现状进行调查。结果显示:昆明地区有珍稀濒危植物42科54属55种,其中真菌有1科1属1种,蕨类植物有3科3属3种,裸子植物有5科7属7种,被子植物有33科43属44种。通过分析昆明地区珍稀濒危植物的种类、生活习性、地理分布特征、保护现状及其濒危原因,提出了相应的保护对策。     

人工湿地处理污染河水和湿地植物腐烂分解影响研究

以高原复合型人工湿地为研究对象,在水力负荷为0.067 m/d的条件下,监测湿地对CODCr、TN、TP、氨氮的去除率达到了66.3%、82.5%、43.2%、76%;采集了梭鱼草、美人蕉、芦苇、水葱、茭白、再力花6种挺水植物地上部分,测定了它们的TN、TP、有机质等营养物质含量和它们腐烂分解过程中TN、TP、COD等释放强度。结果表明:梭鱼草、美人蕉、茭白释放强度较强,再力花和芦苇释放强度较弱,在选择湿地植物时综合考虑植物吸收污染物能力情况下,可以优先考虑再力花、芦苇等植物。     

Can phosphate compounds be used to reduce the plant uptake of Pb and resist the Pb stress in Pb-contaminated soils？

The effects of di erent phosphate-amendments on lead (Pb) uptake, the activities of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in cauliflower (Brassica oleracea L.) in contaminated soils with 2500, or 5000 mg P2O5/kg soil of hydroxyapatite (HA), phosphate rock (PR), single-superphosphate (SSP) and the mix of HA/SSP (HASSP) were evaluated in pot experiments. Results showed that the Pb concentrations in shoots and roots decreased by 18.3%–51.6% and 16.8%–57.3% among the treatments respectively compared to the control samples. The e ciency order of these phosphate-amendments in reducing Pb uptake was as follows: HASSPt HA > SSP t PR.With the addition of SSP, HA and the mix of HA/SSP, the SOD activity in shoot was reduced markedly (P < 0.05) compared with that in the control group. For example, the SOD activities in shoot by the treatments of HASSP, SSP, and HA in 5000 mg P2O5/kg were found to be only 51.3%, 56.2%, and 56.7%, respectively. Similar e ects were also observed on the level of MDA in the shoots with a decrease in 24.5%–56.3%. The results verified the inference that phosphate compounds could be used to reduce the plant uptake of Pb and resist the Pb stress in the plant vegetated in Pb-contaminated soils.     

Bioaccumulation of heavy metals by Phragmites australis cultivated in synthesized substrates

Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution was used as nutrition supply, and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis. After 45-d treatment, the bioaccumulation degree in root followed the order: Al(OH)₃ > Al₂O₃ > Fe₃O₄ > MnO₂ > FeOOH. Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground parts.     

大米中的砷会抑制微量元素的吸收

<正>研究发现:谷类植物摄取了砷元素后会抑制本身微量元素(例如,硒)的含量水平.而硒对人体来说是一种非常重要的微量元素,因为硒能帮助人体去除有害金属砷.这个发现对以大米为主食的亚洲人来说无疑是一个坏消息.     

寄生噬菌体和细菌宿主的本土适应性

<正>"生物多样性"很大程度上取决于外来物种在本土环境中的适应和发展.通常来说,当生存环境发生改变时,寄生生物能为其宿主调节生存竞争压力.已有大量证据表明寄生虫和宿主的确具有本土适应性,但是我们对地球上最为丰富的微生物体——细菌和他们的寄生噬菌体却知之甚少.实际上,微生物多样性最终决定了生态系统的功能和环境的变化.最近一系列的科学研究引发了科学界对微生物多样性的另一话题:那就是生物因素和非生物因素对促进生物多样性的相对重要性.     

Gallic acid和SDS对黑麦草体内重金属亚细胞及形态分布的影响

通过盆栽试验,研究了投加螯合剂没食子酸gallic acid(5mmol·kg-1)与表面活性剂十二烷基磺酸钠SDS(1mmol·kg-1)对黑麦草(Lolium perenneL.)体内重金属亚细胞及形态分布的影响.结果表明,单独投加gallicacid增强了黑麦草对Cd、Pb的区室化作用及对Zn的细胞壁沉积作用;复合投加gallic acid和SDS增强了黑麦草对Cd的区室化作用和细胞壁沉积作用,以及对Zn的细胞壁沉积作用.单独投加gallic acid使黑麦草体内Cd、Zn总量分别增加了33.5%和6.0%,其中,惰性态Cd、Zn所占比例分别增加了6.2%、6.3%;复合投加gallic acid和SDS使黑麦草体内Cd总量增加了35.6%,Zn总量减少了1.1%,其中,惰性态Cd、Zn所占比例分别增加了7.2%、8.6%,增强了植物对Cd、Zn的螯合作用.各处理对Pb的亚细胞分布及形态无明显影响.     

科技潮流

荷兰发明家发明灌溉系统 令沙漠地区植物成活 最近荷兰发明家发明出一种新型自灌溉系统,可以令植物在世界各地的灌木地带、岩石地表、山区、沙漠或任何其它艰难的地区茁壮成长。这种自灌溉水箱Waterboxx由Groasis公司开发．可以捕捉雨水以及空气中的凝结水,为植物提供水源,这样,即使在世界上最干旱的地区,植物也能够成活。     

Heavy metal （Pb,Zn） uptake and chemical changes in rhizosphere soils of four wetland plants with different radial oxygen loss

Lead and Zn uptake and chemical changes in rhizosphere soils of four emergent-rooted wetland plants; Aneilema bracteatum, Cyperus alternifolius, Ludwigia hyssopifolia and Veronica serpyllifolia were investigated by two experiments: (1) rhizobag filled with “clean” or metal-contaminated soil for analysis of Pb and Zn in plants and rhizosphere soils; and (2) applied deoxygenated solution for analyzing their rates of radial oxygen loss (ROL). The results showed that the wetland plants with di erent ROL rates had significant e ects on the mobility and chemical forms of Pb and Zn in rhizosphere under flooded conditions. These e ects were varied with di erent metal elements and metal concentrations in the soils. Lead mobility in rhizosphere of the four plants both in the “clean” and contaminated soils was decreased, while Zn mobility was increased in the rhizosphere of the “clean” soil, but decreased in the contaminated soil. Among the four plants, V. serpyllifolia, with the highest ROL, formed the highest degree of Fe plaque on the root surface, immobilized more Zn in Fe plaque, and has the highest e ects on the changes of Zn form (EXC-Zn) in rhizosphere under both “clean” and contaminated soil conditions. These results suggested that ROL of wetland plants could play an important role in Fe plaque formation and mobility and chemical changes of metals in rhizosphere soil under flood conditions.     

土壤-植物系统中铬的环境行为及其毒性评价

由于铬及其化合物的使用和含铬废弃物的大量排放,空气、土壤、水和食品都不同程度地受到了铬污染.对于铬污染,尤其是与人体健康密切相关的土壤系统铬污染的研究,已成为国内外相关领域的热点.其中铬在土壤-植物系统中的迁移转化规律备受关注.本文详细介绍了铬的基础化学、土壤-植物系统中铬迁移转化的影响因素(土壤理化性质、铬的供给形态、浓度、植物种类等)以及该系统中铬的生态毒性,总结了通过综合分析土壤-植物系统中植物、土壤微生物、土壤动物的生态毒理数据来评估土壤-植物系统中铬生态风险的方法,并指出了这一领域研究工作的不足之处,对今后的研究重点进行了展望.