活性X—3B红染料的生物富集因子及在作物体内的分配

有机染料已成为中国地表环境中重要的一大类有机污染物,采用水培和土壤两种微宇宙生态试验方法,对活性X－3B红染料的生物富集因子（BCF）及在作物体内的分配进行了研究,结果表明,在试验浓度范围内,该化合物BCF为252．1－409．4,根据这一数值和有关评判依据,可知一般生物体对该有机染料具有中等水平的富集能力,各试验作物地下部分对活性X－3B红染料的积累比地上部分至少超出10倍,尤其以根部作为食物的萝卡更为明显,从土壤－作物系统的完整性进行了比较和以地上籽实为粮食的作物来看,各作物及其不同部位对活性X－3B红染料的积累浓度大致为大豆（棕壤）＞小麦（褐土）＞水稻（水稻土）,根＞＞茎秆＞叶＞籽实（不含壳）;而从这些作物在其籽实中积累活性X－3B红染料来看,以累积量为最低的水稻籽实中的最大浓度也可达到23．33μg.kg^-1,可见,该有机染料对环境污染的生态风险不容忽视。     

Sex chromosome homologies between human and fish revealed by the chromosome painting method

Human sex chromosome-specific probes were hybridized to metaphase spreads of three fish species, Monopterus albus Zuiew, Danio rerio and Mastacembelus aculeatus Basilewsky, to reveal evolutionary conservation of sex chromosomal segments between distantly related species of vertebrates. The human X chromosomal paint disclosed 4, 8, and 6 conserved syntenic segments in the karyotypes of the three fish species respectively, which were scattered in several pairs of homologous chromosomes. But no conserved segment was identified in our experiments when the human Y chromosomal probes were used. The evolution of the X chromosome of vertebrates is discussed.     

乙草胺对东北黑土铅形态及生物有效性的影响

通过清洁黑土和污染黑土的形态分级分析和黑土铅对乙草胺的响应实验,对东北黑土铅形态及其乙草胺使用的生物有效性响应进行了研究．结果表明,清洁和污染黑土中的铅均主要以有机质-硫化物结合态铅和残渣态铅这2种生物有效性低的形态为主,而水溶态铅和可交换态铅这2种具生物学活性的铅含量则相对较低．与清洁黑土相比,污染黑土中具生物学活性的铅含量所占总铅含量的比例有所上升．随着农业活动中施入高剂量的乙草胺这一除草剂,黑土中具生物学活性的水溶态和可交换态铅的含量则大幅上升．据分析,其原因是铅在与乙草胺交互作用过程中来自有机质．硫化物结合态铅释放对有效态铅的贡献．     

土壤-植物系统污染生态学研究与展望

为了促进土壤-植物系统污染生态学这门新兴学科的进一步健康发展与学科建设并在今后国家层面上发挥越来越重要的作用,本文回顾了该领域一些具有开端意义的工作与早期研究,并对其学科定义与内涵的发展和基本原理与研究方法的进展给予了追踪,进而就该学科的主要任务和主体研究内容以及今后进一步发展进行了阐述与展望．     

磁处理土壤对油菜幼苗生理生化指标的影响

用室外盆栽方法,将土壤磁效应与生物磁效应相结合,研究磁处理土壤对油菜(Brassica napus)幼苗硝酸还原配活性、可溶性糖含量、根系活力以及生物量的影响．结果表明,200mT磁处理土壤可提高油菜幼苗硝酸还原配活性10．76％,300mT和100mT处理均使可溶性糖含量增加11．05％以上,根系活力增加26．40％．生物量增加,地上部鲜重以300mT处理最大,比对照增加13．28％,地下部的鲜重以200mT处理最大,比对照增加13．17％,根冠比降低10．00％,说明土壤健康质量得到了改善。     

中性环境中铝盐絮凝剂对典型作物的生态毒性效应

采用种子发芽和根伸长抑制的陆生生态毒理方法,在中性条件(pH=7.0)下对铝盐絮凝剂(AlCl₃)的生态毒性效应进行了研究.结果表明,AlCl₃溶液在pH=7.0时,与其酸性条件(pH=4.0)相比对萝卜、白菜和小麦等受试作物种子发芽和根伸长均表现出抑制作用,且发芽抑制率和根伸长抑制率与铝浓度均呈极显著相关(P＜0.01).尽管在酸性条件下AlCl₃对白菜和小麦根伸长抑制效应比相同浓度中性条件更为强烈,但对萝卜根伸长的抑制程度在相同铝浓度条件下则是pH=7.0时明显大于pH=4.0时,在低浓度时萝卜发芽抑制率也是中性条件明显高于酸性条件.同时,铝盐在中性条件下对萝卜、白菜的发芽和根伸长产生明显抑制效应的起始浓度低于酸性条件(＜2.0 mg·L^-1).     

Using Soil Available P and Activities of Soil Dehydrogenase and Phosphatase as Indicators for Biodegradation of Organophosphorus Pesticide Methamidophos and Glyphosate

The heavy use of organophosphorus pesticides in northeastern China strongly affects the ecological functions and the quality of the soil environment. In this work, a 30-day soil incubation experiment was conducted to evaluate the potential of using soil available P and the activities of soil dehydrogenase and acid phosphatase as indicators of the application of methamidophos and glyphosate. Two kinds of unpolluted soils, phaiozem and burozem, were selected as the test soils. The higher application rate of organophosphorus pesticide to the two soils caused more release of PO₄ ^3? which finally entered the soil available P pool, suggesting that soil available P is one of the effective chemical markers for biodegradation of organophosphorus pesticides. Methamidophos exhibited a significant inhibitory effect on the activity of soil dehydrogenase. The extent of enzyme inhibition was almost positively correlated with the insecticide concentration, and the enzyme activity was gradually restored after day 15. However, its effect on soil acid phosphatase activity (stimulation or inhibition) seemed to be indefinite, and varied with the application rate, soil type, and incubation time. In the case of glyphosate, soil acid phosphatase activity was depressed significantly and the depressing extent could be a function of herbicide concentration and incubation time, but soil dehydrogenase activity showed an irregular variation with the herbicide application rate and soil type. In general, dehydrogenase activity was a good biochemical indicator for the biodegradation of methamidophos, but for glyphosate biodegradation the indicator was acid phosphatase activity.     

A Comprehensive Assessment of the Effects of Transgenic Cry1Ac/Cry1Ab Rice Huahui 1 on Adult Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae)

Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae) is a widely distributed coleoptera predator in southern Asia in rice ecosystem, and adult M. discolor feed on both rice pollen and soft-bodied arthropods. Bitrophic bioassay and tritrophic bioassay were conducted to evaluate the potential impact of Cry1Ac/Cry1Ab-expressing rice Huahui 1 and its non-transgenic counterpart Minghui 63 on fitness parameters of adult M. discolor. The results showed that the survival, and fecundity of this beetle’ adults were not different when they fed on Bt rice or non-Bt rice pollen or Nilaparvata lugens (Stål) reared on Bt rice or non-Bt rice. Toxicity assessment to ensure M. discolor adults were not sensitive to Cry1Ab or Cry1Ac protein independent from the pollen background, M. discolor adults were fed with an artificial diet containing Cry1Ac, Cry1Ab or both protein approximately 10 times higher concentration than in Huahui 1 rice pollen. No difference was detected for any of the life-table parameters tested between Cry protein-containing and pure diet. Artificial diet containing E-64 (N-(trans-Epoxysuccinyl)-L-leucine 4-guanidinobutylamide) was included as a positive control. In contrast, the pre-oviposition and fecundity of M. discolor were significantly adversely affected by feeding on E-64-containing diet. In both bioassays, the uptakes of Cry protein by adult M. discolor were tested by ELISA measurements. These results indicated that adults of M. discolor are not affected by Cry1Ab- or Cry1Ac-expressing rice pollen and are not sensitive to Cry protein at concentrations exceeding the levels in rice pollen in Huahui1. This suggests that M. discolor adults would not be harmed by Cry1Ac/Cry1Ab rice if Bt rice Huahui 1 were commercialized.     

Impacts of methamidophos,copper, and their combinations on bacterial community structure and function in black soil

The potential ecotoxicologial risks of methamidophos, copper, and their combinations on microbial community of black soil ecosystem in the Northeast China were assessed in species richness and structures by using 16S rDNA-PCR-DGGE analysis approach, and functional characteristics at community levels by using BIOLOG^GN system analysis method as well as two conventional methods(DHA and SIR). All results of DGGE banding fingerprint patterns(amplified by bacterial specific 16S rDNAV₃ high variable region universal primer) indicated that the species richness of bacterial community in tested soil was significantly decreased to different extents by using different concentrations of single methamidophos, copper, especially some of their combinations had worse effects than their corresponding single factors. In addition, the structures of soil bacterial community had been disturbed under all stresses applied in this study because of the enrichment of some species and the disappearance of other species from the bacterial community. The effects of the single factors with lower concentrations on the community structure were weaker than those with higher concentrations. Moreover, the bacterial community structures under the combined stresses of methamidophos and copper were significantly different from those of control and their corresponding single factors. The change of DHA and carbon source substrate utilizing fingerprint patterns based on BIOLOG^GNsystem were two relatively sensitive directors corresponding to the stress presented in this study. Between methamodophos and copper, there happened the significant joint-toxic actions when they were used in combination on DHA and carbon source substrate utilizing fingerprint patterns of soil bacterial communities. The DHA of soil under the combined stresses was lower than that of the control and that under the single factors, and the BIOLOG^GN substrate utilizing patterns of soil treated by combinations were distinctively differentiated from the control and their corresponding single factors. From all of above, the methamidophos, copper, especially their combinations had the clearly potential ecotoxicological risks to influence the natural soil microbial ecological system by changing the structure, richness, and the functional characteristics of microbial community.     

Screen of Chinese Weed Species for Cadmium Tolerance and Accumulation Characteristics

The cadmium (Cd) tolerance and metal-accumulation characteristics of 29 species (18 families) of weed were studied by using outdoor pot-culture experiments. The results of this screening showed that Bidens pilosa and Kalimeris integrifolia (both Asteraceae) expressed some properties that are characteristic of Cd hyperaccumulators. In 10 mg/kg Cd-spiked soil, they accumulated a good deal of Cd in shoots (28 and 25 mg/kg DW, respectively) with high Cd enrichment factors (EFs; concentration in plant/soil). Cd accumulations in shoots were greater than those in roots (translocation factor (TF) >1, concentration in shoot/root) and the shoot biomasses did not decreased significantly compared to the unspiked control. The other weed species showed little accumulation of Cd, Pb, Cu, or Zn. In a concentration-gradient experiment, the Cd accumulation potentials of B. pilosa and K. integrifolia were examined further. Cd concentrations in leaves of B. pilosa growing in soils spiked with 25, 50, and 100 mg/kg Cd were up to 145, 160, and 192 mg/kg, respectively, and the Cd content in stems in the 100 mg/kg Cd-spiked soil was 115 mg/kg, all greater than the 100 mg/kg notional criterion for Cd hyperaccumulation. The Cd EFs and TFs were all greater than 1. The shoot biomasses did not decrease significantly compared to the controls. B. pilosa was thus shown to have some characteristics of a true Cd hyperaccumulator plant.