UV-B辐射对大豆和黄瓜幼苗某些生理特性的影响

在植物生长室中,ＵＶ－ Ｂ辐射明显降低黄瓜幼苗的根系活力,抑制程度随辐射时间的延长而增强．黄瓜和大豆幼苗的叶绿素和可溶性蛋白含量减少与ＵＶＢ辐射时间长短呈正相关,但是类胡萝卜素减少幅度不大．ＵＶＢ对Ｃｈｌｂ 的破坏较Ｃｈｌａ 严重,导致Ｃｈｌａｂ 比值增大．ＵＶＢ虽增加大豆幼苗的ＳＯＤ活性,但降低大豆幼苗的ＮＲ活性及其对温度变化的敏感性．分析认为,Ｃｈｌａｂ 比值和ＳＯＤ 活性升高,有助于植物对ＵＶＢ的适应     

污染稻、麦籽实中Cd、Cu、Pb的分布及其存在形态初探

采用组织化学及溶剂提取法研究了污染水稻、小麦籽实中Cd、Cu、Pb的分布及存在形态．结果表明,3种金属元素在水稻、小麦籽实各形态结构中的浓度具有明显不均一性,胚中浓度显著高于胚乳,颖壳,皮层中浓度也较高;糙米、麦粒中的Cd、Cu、Pb在去离子水、0.1mol EDTA、1％醋酸、2.5％　NaCl、0.2％NaOH、70％乙醇中的溶出比例有显著差异;综合2项试验结果可以看出Cd、Cu、Pb在籽实中主要与谷物成分结合形成配合物,其优势形态是蛋白质结合态．     

水溶性有机物对土壤中菲的生态毒性影响

采用生物培养和物理化学试验,研究了水溶性有机物(DOM)对土壤中phe生态毒性的影响.结果表明,本研究所用DOM均具有表面活性;小麦根phe毒害的敏感区间为0～200mg/kg,200mg/kg是土壤中phe的50%小麦根伸长抑制率浓度.DOM的存在会降低phe的生态毒性,但是降低程度与其疏水性馏分含量和表面活性有关,且phe生态毒性的降低程度随DOM浓度的增大而增大.本研究的结果说明DOM能减轻土壤中phe的生态毒性.     

镉胁迫对苎麻(Boehmeria nivea)根系及叶片抗氧化系统的影响

镉(Cd)是非必需和毒性最强的重金属元素之一,不合理的开发利用可导致土壤受到Cd的严重污染,严重危及土壤环境或水环境。以苎麻为材料,采用模拟镉(Cd)污染盆栽培养法,选择21 d和49 d等2个不同胁迫期,测定不同浓度Cd2+胁迫下苎麻根系与叶片中渗透调节物质含量、超氧化物岐化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量及根系活力的变化。结果表明,高浓度胁迫49 d后,苎麻根系中的渗透调节物质含量明显高于叶片含量,且极显著高于对照,并在240 mg·L~(-1)Cd处理下出现最高值;胁迫49 d时,根系与叶片的渗透调节物质含量与Cd2+浓度极显著正相关。在2个不同胁迫周期,苎麻根系的SOD与POD活性均明显高于叶片;在胁迫21 d时,根系的CAT活性低于叶片,而胁迫49 d后,则明显高于叶片;胁迫21 d时,苎麻根系与叶片的抗氧化酶活性均较胁迫49 d要高;胁迫49 d时,根系POD活性与Cd2+浓度呈极显著正相关,表明根系POD酶在抗氧化酶中占主导地位。不同胁迫时长下苎麻根系或叶片的MDA含量变化趋势不明显,但根系或叶片受胁迫21 d后的MDA含量随Cd2+浓度增加的波动相对受胁迫49 d后的更明显,表明植物早期生理功能出现暂时性的修复。2个不同胁迫周期内,不同浓度镉胁迫下苎麻的根系活力均比对照组下降。研究显示,苎麻根系与叶片对镉胁迫的应答机制不同,且在不同胁迫时间下的响应机理差异较大,根系表现出更强的耐受能力。     

小麦根系菲与磷吸收及转运的相互作用

作物根系对多环芳烃(PAHs)与磷吸收及转运之间的相互作用研究对农产品的安全生产和PAHs污染环境植物修复的强化具有重要意义。为此,本文以菲为PAHs的代表,采用水培试验研究了不同磷、菲水平下小麦根系菲、磷吸收及其转运的效果,旨在揭示植物根系吸收PAHs与磷素的相互作用。结果表明,在0~1 200μmol·L~(-1)磷浓度范围内,小麦根系、茎叶菲含量在低磷浓度(10μmol·L~(-1))时最高,分别为36.87 mg·kg~(-1)和2.07 mg·kg~(-1);磷含量总体呈现随磷处理浓度的升高而增大的趋势;成对数据t-检验显示无论加菲与否,根系、茎叶磷含量无显著性差异(P0.05)。磷可促进菲从根部向地上部转运,而菲对磷转运没有显著性影响。在低磷浓度下(10μmol·L~(-1)),随着菲浓度的升高,小麦根系、茎叶菲含量呈现显著升高趋势(P0.05)。磷、菲共存处理介质pH升高幅度大于单一处理。     

菌根真菌侵染对植物生物量累积的影响

为了从生态系统尺度探讨菌根资源与植物生物量累积的关系,调查了鼎湖山不同成熟度的三个森林群落主要优势树种的菌根侵染情况.综合分析各森林群落优势树种的个体数、生物量和菌根侵染率发现：1）菌根侵染率与径向生长速率相关,植物生长迅速的阶段菌根侵染率更高.中径级（胸径15-30 cm）的马尾松（Pinus massoniana）和锥（Castanopsis chinensis）的侵染率比小径级（胸径1-15 cm）个体的侵染率高,而大径级个体（胸径30 cm 以上）的侵染率略低于中径级个体的侵染率.木荷（Schima superba）则表现出侵染率随着胸径增大而增高的趋势.2）树种在群落内的侵染率越高,其对群落生物量的贡献率越大.如马尾松在马尾松林和混交林的侵染率分别为（77.30±18.02）%和（40.50±14.42）%,其对马尾松林群落生物量的贡献率达到87.43%,是对混交林生物量贡献率（17.51%）的5 倍.混交林和阔叶林的共有优势树种锥的侵染率和生物量贡献率也有存在相同规律.3）根系碳储量占群落总碳储量比例较高的群落其优势树种平均侵染率相对较高.马尾松林、混交林和季风常绿阔叶林中,根系碳储量占群落总碳储量的比例分别为55%、54%、42%,群落优势树种平均侵染率分别为（66.73±10.55）%、（46.97±27.28）%、（54.22±25.45）%,马尾松林的根系碳储量和平均侵染率均高于混交林和季风常绿阔叶林.以上结果表明,菌根真菌侵染对于植物个体生长速率以及群落水平的生物量累积具有-定的促进作用.     

磷在农田溪流中的动态变化

磷是水体富营养化的限制因子,河流系统是农业非点源污染物的主要运移通道,污染物在河流中的持留控制着污染物向受纳水体的输出.本次研究对象是巢湖流域一个长约1.8 km的农田源头溪流六岔河,河流由4个渠道型、1个水塘型和3个河口型断面构成,长度分别为1.3 km、0.15 km和0.36 km.在河流上设置9个监测点研究总磷、磷酸盐和悬浮物在六岔河中的持留空间特征,评价人为严重干扰下的农田溪流在农业非点源污染物运移中的生态功能.结果表明:总磷、磷酸盐、悬浮物在溪流中的持留和释放受溪流的渠道型、水塘型和河口型断面控制,水塘型和河口型断面是污染物持留的主要区域,总磷、磷酸盐和悬浮物在水塘型、河口型断面内的持留量分别占溪流持留量的58%、77%和58%;污染物在降雨-径流过程中的持留是溪流持留的主要部分,总磷、磷酸盐和悬浮物的持留分别占溪流持留量的96%、98%和93%;渠道型断面是溪流最主要的内在污染源,总磷、磷酸盐和悬浮物的释放分别占溪流释放量的93%、99%和94%;养分和悬浮物在渠道型断面中具有不同的持留特性,而位于水塘前的渠道型断面在基流和降雨-径流过程中均能有效地持留污染物.     

Evaluation of potential toxic effects of occupational inhalation exposure to licorice root dust

Licorice, a plant indigenous to southern Europe, the Middle East, and northern China, exhibits several pharmacological properties, including estrogenic, anti-tumoral, anti-inflammatory, anti-allergenic, and anti-tussive activities. Prolonged use of licorice is known to produce headaches, hypertension, cardiac arrhythmias, edema, lethargy, dyspnea, sodium retention and loss of potassium in humans. However, to date, the potential adverse health effects due to occupational inhalation exposure of licorice root dust remains unknown. This study was, therefore, undertaken to address this issue. In this cross-sectional study, individuals (30 workers) occupationally exposed to licorice root dust at a licorice producing plant in Shiraz, Iran were recruited. Similarly, 30 healthy male unexposed employees at a telecommunications industry, with identical demographic and socioeconomic status, without any past or current exposure to licorice dust or habitual ingestion of this compound, served as the referent group. Systolic and diastolic blood pressures were measured. Further, individuals underwent electrocardiography, clinical examination and blood chemistry tests. To assess the extent to which subjects were exposed to licorice root dust, atmospheric concentrations of this compound were also measured in the plant. There were no differences in age, weight, height and duration of exposure to licorice dust or length of employment between exposed and referent groups. Atmospheric measurement of licorice dust showed that concentration exceeded the permissible limit of 5 mg m^?3. Systolic and diastolic blood pressures of exposed subjects were significantly higher than those of the referent group. Similarly, blood analysis revealed that serum concentrations of potassium and platelet counts were significantly lower in exposed subjects than in referent individuals. Questionnaire data demonstrated that symptoms such as headaches, lethargy, and vertigo were more common in exposed subjects. No abnormal changes were noted in the electrocardiographs of exposed or referent subjects. Our findings provide evidence that inhalation exposure to high concentrations of licorice dust is associated with an increased prevalence of headache, lethargy, and vertigo, as well as hypertension and hypokalemia. None of these changes resulted in increased morbidity and mortality in exposed workers.     

Relationships Between Copper Species and Forms,Hydrographic and Biomass Parameters in the Taiwan Erhjin Chi Coastal Area

The first incident of green oysters (Crassostrea gigas) was reported in Taiwan in the Charting coastal area in January, 1986 and mortality was reported three months later. the cause of the greened oysters was identified as copper pollution. the copper content of the green oysters was extremely high - 2100 ppm, 2225 ppm, and 4400 ppm dry weight, in January, 1986, February 1987, and January 1989, respectively. in this paper we summarize the seasonal and regional distributions of copper species (complexed by inorganic and organic ligands, labile and non-labile, polar and non-polar) and forms (dissolved and particulate) and the hydrographic and biomass parameters (mainly particulate organic carbon, chloropyll -α, adenosine triphosphate and primary production) in sea water in the Erhjin Chi coastal area. in general, high concentrations of particulate material (0.24 to 724 ppb) and non-labile organic copper (0.03 to 21.5 ppb) were observed. Low values of polar organic copper (<0.02 to 16.5 ppb) indicated that non-polar organic complexes (0.3 to 20.4 ppb) from man-made organic pollutants were the major complexes in the area studied. On the basis of this data, the cause of greening and mortality in oysters is evaluated in relation to the bioavailable copper (sum of particulate and labile copper) and copper assimilative capacity (detoxicant). Finally, the correlations between the species and forms of copper, hydrographic and biomass parameters are also discussed.     

氯丹和灭蚁灵污染场地土壤对陆生生物的毒性效应

为向污染土壤的监测、生态毒理诊断及修复提供方法和数据,以氯丹、灭蚁灵污染场地土壤为供试土壤,测定了氯丹、灭蚁灵复合污染对蚯蚓的急性毒性效应以及对小麦、小白菜、玉米和水稻4种植物种子发芽率和根伸长抑制率的影响.结果表明,蚯蚓对本场地污染响应十分敏感,处理d 3高浓度组开始出现死亡,此后死亡率随污染物浓度增大而上升,d 14部分高浓度组死亡率达到100%;同一浓度下,氯丹和灭蚁灵对4种植物种子根伸长抑制率均显著大于对种子发芽的抑制率,植物的根生长比种子发芽对有机污染物的毒性更为敏感.4种植物种子对污染场地土壤的敏感性为小麦>小白菜>水稻>玉米.氯丹和灭蚁灵对蚯蚓的毒性要大于对这几种植物的毒性,蚯蚓对氯丹和灭蚁灵的响应更加敏感.因此,蚯蚓作为指示生物,其急性毒性试验可作为氯丹和灭蚁灵污染场地的诊断指标,诊断周期以14 d为宜.