三唑酮对离体黄瓜子叶过氧化物酶活性及蛋白质含量的影响

20mg/L三唑酮能显著地抑制离体黄瓜子叶叶绿素a、b、可溶性蛋白质和游离脯氨酸含量及叶绿素a/b的下降,表明三唑酮抑制子叶的衰老。与此同时,三唑酮能不同程度地抑制过氧化物酶（POD）活性升高和H2O2的累积。在黄瓜子叶衰老过程中,叶绿素及蛋白质含量均与POD、H2O2成显著的负相关,表明三唑酮可能通过POD－H2O2酶促系统来抑制叶绿素和可溶性蛋白质的降解。     

模拟酸雨对烤烟叶片光合特性和叶绿素荧光参数的影响

以烤烟为供试材料,采用土培盆栽的方法研究了不同pH值的模拟酸雨(pH5.6、pH4.5、pH4.0、pH3.5、pH3.0、pH2.5、pH2.0)对烤烟叶片叶绿素含量、气体交换和叶绿素荧光参数的影响.结果表明:pH≥3.5处理的轻度酸雨对烤烟Chl.a含量影响不大,但pH≤3.5处理烤烟叶片Chl.b和总叶绿素含量显著下降.pH≤2.5模拟酸雨使烤烟叶片净光合速率(Pn)、气孔导度(Ls)、胞间CO2浓度(Ci)、叶面饱和蒸气压力亏缺(VPD)显著降低,使烤烟叶片的气孔限制值(Ls)和潜在水分利用效率(WUEi)显著升高,模拟酸雨使pH2.0处理烤烟叶片的蒸腾速率(Tr)和pH2.5处理的瞬时水分利用效率(WUE)显著降低.pH≥3.5处理的光合有效量子产量(EQY)、光合电子传递速率(ETR)和光化学猝灭(qP)与对照差异不大,但pH≤3.0处理明显降低;烤烟叶片的非光化学猝灭呈先升高后降低趋势,pH≥3.5处理的非光化学猝灭(NPQ)明显高于pH≤3.0处理.     

氯酚类化合物对紫背浮萍生长及叶绿素含量的影响

以我国本土水生植物紫背浮萍为受试物种,利用其生长抑制和叶绿素含量的变化评价了3种氯酚类化合物的毒性效应.结果显示:2,4-二氯酚(2,4-DCP), 2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)对紫背浮萍的96h IC50值分别为12.73,8.49,1.12mg/L.根据化学物质对水生生物毒性分级标准,3种物质均为高毒.2,4-DCP,2,4,6-TCP和PCP对紫背浮萍基于叶绿素含量变化的最大可接受浓度(MATC)分别为2.24,1.58, 0.35mg/L,对应的急慢性毒性比(ACR)分别为5.68,5.37和3.20.     

Modelling the meteorological influence onthe yellowing of spring wheat leaves

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镉胁迫对小麦叶片细胞膜脂过氧化的影响

镉胁迫使植物体内活性氧自由基清除系统的功能降低,造成细胞内H₂O₂积累,抗坏血酸过氧化酶和谷胱甘肽还原酶活性下降,内源抗氧化剂抗坏血酸和谷胱甘肽含量减少,小麦叶片的组织自动氧化速率显著提高。细胞内丙二醛的积累表明,膜脂过氧化发生和膜系统受到损伤。推测小麦镉伤害过程中,活性氧自由基代谢失衡造成的膜脂过氧化起着重要作用。     

增强UV-B辐射对小麦叶片黄酮类化合物日变化的影响

通过温室盆栽试验,初步研究了UV-B辐射对灌浆期小麦叶片中黄酮类化合物含量日变化的影响.结果发现,UV-B胁迫条件下,黄酮类化合物含量明显上升,而胁迫解除后,其含量下降,与对照组间差异逐渐减小.合成黄酮类化合物的关键性酶--苯丙氨酸解氨酶活性的变化也表现出大致相同的趋势.同时,UV-B辐射对小麦叶片净光合速率没有影响,但使其夜闯呼吸速率显著加强 .这些结果表明,小麦在UV-B胁迫解除前后黄酮类化合物的持续波动可能是植物在UV-B辐射条件下光合能力未受影响而生物量明显下降的一个重要原因.     

UV-B辐射对小麦叶抗氧化系统的影响

研究了温室种植的小麦在０（ＣＫ）、８．８２ｋＪ／ｍ＾２（Ｔ１）和１２．６ｋＪ／ｍ＾２（Ｔ２）三种剂量的紫外线Ｂ（ＵＶ－Ｂ）辐射下抗氧化系统的变化及其原因。ＵＶ－Ｂ辐射诱导了Ｈ２Ｏ２的合成，还原型抗坏血酸和还原型谷胱甘肽含量的增加、过氧化氢酶、愈创木酚过氧化物酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性升高，而类胡萝卜素稍有所降低、超氧歧化酶（ＳＯＤ）活几乎不受ＵＶ－Ｂ辐射影响，分析表明，ＵＶ－Ｂ辐射     

NO参与铝诱导蚕豆保卫细胞死亡的调控

铝(Al)是地壳中含量最丰富的金属元素,是酸性土壤中导致植物生长抑制和作物产量下降的一个主要因素,但铝毒性作用机制尚不清楚.本文以蚕豆叶表皮为材料,研究铝胁迫对气孔保卫细胞活性的影响,探讨NO在铝诱导细胞死亡中的作用.结果表明,一定浓度的A1Cl3可诱导气孔保卫细胞活性降低,部分细胞死亡,且随着铝浓度的增高细胞死亡率增高.死细胞呈现核固缩、核崩解、凋亡小体等典型凋亡特征,且凋亡抑制剂Z-Asp-CH2-DCB能阻止AlCl3诱发的细胞死亡.用NO清除剂c-PTIO、NO合酶抑制剂L-NAME或硝酸还原酶抑制剂NaN3降低铝处理组胞内NO后,细胞死亡率显著降低,胞内ROS、Ca2+水平同期降低;NaN3还能降低铝处理组中具有程序性死亡特征的细胞比率.用ROS清除剂AsA清除铝处理组胞内ROS后,细胞死亡率显著降低,胞内Ca2+和NO水平亦显著降低;铝处理液中加入Ca2+通道抑制剂LaCl3后,细胞死亡率低于铝单独处理组,胞内ROS和NO水平无明显改变.研究结果表明,铝胁迫引起的胞内NO合成增加通过Ca2+信号途径介导了保卫细胞的程序性死亡.     

Elemental content of soil,sorghum and wheat on sludge-injected agricultural land

The objective of this research was to determine the uptake of heavy metals by plants grown on sludge-injected soil. The study took place at the sludge farm owned by the Manhattan, Kansas, sewage treatment plant, where sludge has been injected since 1976. Soil and two crops, sorghum (Sorghum bicolor L. Moench.) and winter wheat (Triticum aestivum L. em. Thell.), were sampled in 1980 after a total of 128 t ha^?1 of sludge (dry-weight basis) had been added to the soil (32 t ha^?1 year^?1). The control area, a farm next to the sludge farm, received only inorganic fertilizer. Four non-essential elements were analyzed (Cd, Cr, Ni, Pb), as well as nine essential elements (N, P, K, Ca, Mg, Cu, Fe, Mn, Zn).Soil in sludge-fertilized fields had more N, P, K, Mg, Fe, Cu, Mn, Zn, Cd, Cr and Ni than did soil from the control fields. In general, concentrations of essential elements in plants grown on sludge were similar to concentrations of essential elements in plants grown with inorganic fertilizer. Concentrations of non-essential elements were also similar, except for the following five exceptions, in which the sludge-treated plants had a higher concentration of the element than did the control plants: Cd in stems of sorghum; Cr in roots of wheat; Ni in roots and grain of wheat; and Pb in roots of wheat. Nickel in grain of wheat grown with sludge was within normal concentration ranges. Cadmium was at low levels in all plants, which indicated that, when sludge was layered below the surface of the soil, transfer of Cd from the soil to the plants was small. Sludge-injection appeared to be an effective method for fertilizing plants.     

苯并咪唑衍生物缓蚀机理的理论研究

目的对五种苯并咪唑衍生物缓蚀剂的缓蚀性能进行理论评价,并对其缓蚀机理进行理论研究。方法采用量子化学计算与分子动力学模拟相结合的方法。结果苯并咪唑、2-丙基苯并咪唑、2-戊基苯并咪唑、2-己基苯并咪唑的最高占据轨道(HOMO)和最低空轨道(LUMO)均分布在苯并咪唑环上,而2-对氯苄基苯并咪唑的最高占据轨道分布在苯并咪唑环上,最低空轨道分布在取代基上。分子的苯并咪唑环平行吸附在金属表面,取代基含有的烷基链会垂直于表面并指向溶液,对分子吸附的影响较小,而取代基含有的苯环则会发生平行吸附。在五种缓蚀剂分子中,苯并咪唑的能隙差(ΔE)为5.572 e V,在金属表面上的吸附能为364.19 k J/mol,缓蚀性能最弱;2-对氯苄基苯并咪唑的能隙差为5.157 e V,吸附能为700.19 k J/mol,缓蚀性能最强。结论苯并咪唑衍生物分子的取代基官能团会对缓蚀性能造成一定影响,缓蚀剂分子通过其前线轨道与Fe原子形成的配位键和反馈键稳定吸附在金属表面,吸附形态和前线轨道分布有关。     

Effects of SO2 on physiology,elemental content and injury development of winter wheat

The effects of sulfur dioxide on buffering capacity, chlorophyll content, stomatal conductance, mineral composition and leaf injury of winter wheat (Triticum aestivum, cv. Yecora Rojo) were studied. Plants were exposed to sulfur dioxide (0, 79, 183, and 393 μg m⁻³) in open-top chambers. Exposures were conducted in Riverside, California, during the coolest part of the year when the plants are believed to be more sensitive to sulfur dioxide than during the rest of the year. Physiological measurements, injury rating and collection of leaf material for chemical analysis were carried out after 22 days of exposure. The results of these measurements were compared with yield data from the final harvest which took place after 118 days of exposure. Elevated SO₂ concentrations caused decrease of buffering capacity, increase of total sulfur content and increase of injury of wheat leaves. These changes correlated significantly with reduction of total seed weight and weight of 100 wheat seeds at the final harvest. Stomatal conductance to water vapor, chlorophyll content and two leaf mineral concentrations (calcium, potassium) were not significantly affected by sulphur dioxide exposure. The results of this study indicated that buffering capacity, total sulfur content and injury of leaves could be used as early indicators of SO₂ stress in wheat and its subsequent yield losses.     

黄河三角洲土壤(潮土)石油类含量对小麦的影响研究

本文在分析黄河三角洲土壤石油类含量状况、通过盆栽试验研究小麦对当地土壤 (潮土 )石油类含量耐受度的基础上 ,建立物流模型 ,得出了在不受污油、落地油污染的地方土壤 (潮土 )石油类含量对小麦的不利影响在较长时间内将是微弱的基本结论。     

辽东湾海冰晶体结构及其内部叶绿素的初步研究

本文介绍了１９９６年冬季首次辽东湾生态环境调查中的海洋背景条件。扼要地阐述了辽东湾海冰一般概况，分析辽东湾冰样晶体结构、存储条件及其与冰内和冰下海水叶绿素之间的关系。辽东湾冰内叶绿素符合其它结冰海区的一般规律。根据辽东湾冰层底部实测盐度变化规律阐明海冰对冰下海水营养盐的贡献。最后对深入开展结冰海区生态环境调查工作的技术、侧重点和意义做了讨论。