固氮菌与氮配施对生菜及油菜产量和品质的影响

采用盆栽试验研究了固氮菌(M)与氮(N)配施对生菜、油菜产量和品质的影响.结果表明:施加固氮菌(M2)后,生菜、油菜的鲜重和干重较之不加固氮菌(M1)有显著增加趋势,生菜、油菜的Vc含量分别提高4.2%~18.6%、17.6%~35.0%,还原糖含量分别提高17.6%~35.0%、6.7%~41.3%,硝酸盐含量分别降低40.5%~57.2%、22.8%~40.8%.在所有处理中,处理M2N3的两种蔬菜产量最高,品质最好.研究可为固氮菌肥的合理有效施用、氮肥的优化配比及叶菜类蔬菜高产优质的生物调控提供理论依据.图1表3参13     

Characteristics of dispersions and water-soluble extracts of crude and refined oils and their toxicity to estuarine crustaceans and fish

The quantitative hydrocarbon composition and behavior in seawater of water-soluble fractions (WSF) and oil-in-water dispersions (OWD) of 4 oils was investigated. Two crude oils, South Louisiana crude and Kuwait crude, and two refined oils, No. 2 fuel oil and bunker C residual oil, were used in these investigations. The WSFs of the crude oils had higher total oil-hydrocarbon concentrations and were richer in light aliphatics and single-ring aromatics than were the WSFs of the refined oils. The WSFs of the refined oils contained significantly higher concentrations of naphthalenes than did those of the crudes. The hydrocarbon composition of the aqueous phase of OWDs closely resembled that of the parent oils. Gentle aeration of the OWDs resulted in a loss of 80 to 90% of the aqueous hydrocarbons in 24 h. Alkanes disappeared from the dispersions more rapidly than aromatics. The WSFs and OWDs of the refined oils were considerably more toxic to the 6 test species than were those of the crude oils. The test species can be ranked according to increasing sensitivity to oil as follows: Cyprinodon variegatus, Menidia beryllina, Fundulus similus, Penaeus aztecus postlarvae, Palaemonetes pugio and Mysidopsis almyra. The results of this investigation are discussed in relation to the potential impacts of oil spills on the marine and estuarine environments.     

恩诺沙星与Cu复合污染对白菜和西红柿根及芽伸长的抑制作用

抗生素恩诺沙星和重金属Cu是当今我国土壤中较常见的污染物。本研究考察了恩诺沙星与Cu复合污染对砖红壤中白菜和西红柿种子的根及芽伸长的影响,以评估恩诺沙星和Cu复合污染潜在的生态风险。结果表明,加入不同浓度的Cu时,土壤中的恩诺沙星浓度与2种作物的根伸长和芽伸长的抑制率均显著相关(P0.05);白菜的敏感性均大于西红柿;白菜和西红柿的根伸长对复合污染的生态毒性的敏感性均较芽伸长更高;与单一恩诺沙星胁迫相比,在恩诺沙星与Cu(100 mg·kg~(-1))或Cu(300 mg·kg~(-1))复合污染下,二者对白菜和西红柿的根及芽伸长抑制效应均表现为协同作用。试验结果在揭示恩诺沙星与Cu复合污染的生态毒性效应的同时,也为重金属和抗生素复合污染的生态风险评价提供科学依据。     

费氏中华根瘤菌ntrBC基因突变株的构建及其特性

从费氏中华根瘤菌(Sinorhizobium fredii)HN01基因文库的重组质粒pGXHN300上获得ntrB、ntrC基因完整序列.通过自杀质粒pK18mob同源单交换的方法,分别获得了HN01菌株的ntrB和ntrC基因的突变株GXHNB、GXHNC.功能检测证明GXHNB、GXHNC能以硝酸盐为唯一氮源进行正常生长,但不能以铵源作为唯一氮源进行正常生长.图4表2参15     

Plasmatic resistance and rate of respiration and photosynthesis of Zostera marina at different salinities and temperatures

Zostera marina L. was studied at the Izembek Lagoon, Alaska Peninsula. Two morphologically different forms, tidepool and subtidal, can be distinguished. Both show a high tolerance to different salinities and temperatures. The plasmatic resistance was found in a range of distilled H₂O up to 3.0 seawater (24 h) and between-6° and 34°C (12 h). Within these resistance limits, the photosynthesis, which has its maximum in normal (1.0) seawater, decreases nearly to zero not only in distilled H₂O but even in 2.0 seawater, and increases with the temperature in the tidepool form up to 35°C, but in the subtidal form up to 30°C only. At higher temperatures photosynthesis declines sharply in both forms. Respiration has its minimum in distilled H₂O and at 0°C and increases with increasing salinity and temperature.Dedicated to Prof. Dr. Dr. h. c. mult. K. Mothes, Halle, Germany (DDR) on the occasion of his 70th birthday.     

多效唑在番茄和土壤中的残留与降解动态研究

研究了多效唑（paclobutrazol）在番茄（Lycopersicon eseulentum）和土壤中的残留分析方法及残留动态。建立番茄和土壤样品中多效唑残留的固相萃取-高效液相色谱（SPE-HPLC）检测方法,样品用乙腈提取,再用φ（甲醇-二氯甲烷）=5∶95混合溶剂经LC-NH2固相萃取柱净化,以φ（乙腈-水）=55∶45作流动相,Shiseido C18色谱柱（4.6 mm×250 mm,5μm）于222 nm波长检测,外标法定量。在0.1~5.0 mg·L-1范围内,多效唑峰面积与其质量浓度之间呈良好线性关系,相关系数为0.9995。采用田间试验方法,在番茄幼苗期施用不同多效唑质量分数50、100、200、600 mg·kg-1,研究在不同处理时间1、6 h,1、2、3、7、14、21、30、45、60 d,多效唑在番茄以及土壤中的残留动态变化。添加质量分数水平为0.05、0.1、0.5 mg·kg-1时,多效唑在果实、植株和土壤中的添加回收率分别为92.45%~103.70%、94.52%~98.85%和94.30%~102.10%,变异系数分别为3.69%~5.00%、1.58%~4.53%和1.28%~3.35%。结果表明：多效唑在番茄植株和土壤中的降解规律均符合一级动力学方程C=Coe-kt。当施用质量分数为600 mg·kg-1时,其在番茄植株中的残留半衰期为1.66 d,在土壤中的半衰期为2.78 d;在植株中的降解速率大于在土壤中的降解速率。按照推荐使用的施用浓度,采收时多效唑在番茄和土壤中无残留,证明推荐施用浓度是合理的。     

Individual and combined effect of mercury and manganese on phenol and proline content in leaf and stem of mungbean seedlings

Mungbean (Vigna radiata L. Wilczelk cv. Pusa Baisakhi seedlings were raised in individual (0, 1, 10, 100 and 1000 ppm) and combined solutions (1 : 1, 10: 1, 1: 0 ppm Hg : Mn) of mercury and manganese for 6 days. Phenol and proline were found to accumulate in leaves in response to treatment with heavy metals. The magnitude of accumulation correlated with concentration of metals. However, a reverse trend was noticed in stem for phenol. Accumulation of phenol in response to heavy metal treatment was organ specific and occurred at higher rate in plant parts, which faced the stress mostly. However, accumulation of proline helped the plant to survive stress situation. In combined solutions, amelioration of mercurial toxicity by manganese was recorded.     

方位及冠层对厚朴果实和种子形态变异的影响

为从方位及冠层的角度探讨光照对厚朴(Magnolia officinalis)果实和种子形态变异的影响,分别从植株的不同方位和冠层采集果实、种子,并测定其形态指标。结果表明,方位对厚朴果实和种子的形态变异影响显著,不同方位厚朴果实和种子的表型性状表现为南方位和东方位优于西方位,南、东和西3个方位均优于北方位;冠层对厚朴果实和种子的形态变异影响显著,不同冠层果实和种子性状表现为中冠层优于上冠层,上冠层优于下冠层;方位和冠层对厚朴果实和种子多项形态指标的协同作用不显著。与果实相比,种子的表型性状更稳定。     

河岸缓冲带对氮磷的截留转化及其生态恢复研究进展

河岸缓冲带是河岸生态系统的重要组成部分,对农业非点源污染物起到有效的截留转化作用。对河岸缓冲带的定义、生态结构特性和功能,河岸缓冲带对氮和磷的截留转化作用以及河岸缓冲带的生态修复现状进行了综合评述。结果表明：草地和森林类型河岸缓冲带均能有效地控制氮和磷向水体中迁移;河岸缓冲带的宽度、水文特征、土壤性质、季节变化以及人为活动等是影响其截留效率的因素;加强退化河岸缓冲带的恢复重建工程,可以保证河岸生态系统的健康。针对目前研究中的不足,提出今后的研究方向,认为应进行长期的大尺度的野外实践研究,并从生态学的角度出发,建立合理的河岸缓冲带健康指标,为退化河岸缓冲带恢复重建提供科学依据。     

Enzyme activities of fish skeletal muscle and brain as influenced by depth of occurrence and habits of feeding and locomotion

Activities of lactate dehydrogenase (LDH), pyruvate kinase (PK), malate dehydrogenase (MDH) and citrate synthase (CS) were measured in the white skeletal muscle of marine fishes having different depths of occurrence and different feeding and locomotory strategies. There were significant depth-related differences in the two glycolytic enzymes, LDH and PK. LDH activity was most variable, and differed by 3 orders of magnitude between the most active shallow-living species and certain deep-sea fishes likely to have only minimal capacities for active locomotion. Superimposed on the depth-related patterns was a high degree of interspecific variation (up to 20-fold) in enzymic activity among species from any given range of depth of occurrence. Variation of both LDH and PK activities, noted for shallow- and deep-living fishes, seems to be largely accounted for by differences in feeding habits and locomotory performance. Active pelagic swimmers have much higher activities of LDH and PK than, for example, deep-living sit-and-wait predators. Benthopelagic fishes like rattails and the sablefish have the highest activities found among deep-living fishes, suggesting that these species engage in relatively active food-searching behavior compared to most other deep-sea fishes. The activity of CS, an enzyme of the citric acid cycle and an indicator of aerobic metabolism, varied little among species. Thus, the large interspecific variation in glycolytic potential (LDH and PK) among species is not associated with a similar variation in aerobic metabolism of white muscle. The much higher and more variable activity of MDH relative to CS suggests that, in addition to its function in the citric acid cycle, MDH may play an important role in redox balance in fish white muscle. In a comparison of white muscle composition between the shallow- and deep-living species, water content did not differ significantly, but protein content was significantly higher in shallow- than in deep-living fishes (211 and 130 mg g^-1 wet wt of muscle, respectively). The differences in muscle protein content are small relative to the differences between shallow- and deep-living species in LDH, PK and MDH activities. Thus, depthrelated differences in muscle enzymic activity are caused by factors other than enzyme dilution. Enzyme activities (LDH, PK and CS) in brain tissue were relatively constant among species regardless of depth of occurrence or feeding and locomotory habits. Habitat and lifestyle do not seem to influence the demands for overall metabolic function in brain. The utility of muscle enzymic activity data for making predictions about the ecological characteristics of difficult-to-observe, deep-living, fishes is discussed.     

污泥和盐渍土混配介质的性质及对5种野生植物生长的影响

将污泥与滨海盐渍土按照不同比例(污泥质量分数分别为0、20%、40%、60%、80%和100%)混配,开展三叶鬼针草(Bidens pilosa)、稗(Echinochloa crusgalli)、荆芥(Schizonepeta tenuifolia)、金叶马兰(Kalimeris indica)和蒲公英(Taraxacum mongolicm)5种野生植物的盆栽试验,研究污泥混配介质的理化性质,污泥比例对植物成活率、叶绿素含量和干质量的影响,以及植物体内各种重金属的累积浓度,探索污泥在滨海区盐渍土中的最佳施用比例,并对野生植物资源进行评价。结果表明,污泥改良滨海盐渍土是可行的,污泥质量分数为20%～60%时,混配介质的理化指标符合CJ/T 340—2011《绿化种植土壤》,Cd、Cu、Zn、Cr、Pb和Ni含量符合GB 15618—95《土壤环境质量标准》中的二级标准,并以60%污泥+40%滨海盐渍土的质量配比效果最佳,该混配介质中植物存活率达100%;三叶鬼针草、稗子、荆芥、金叶马兰和蒲公英是上海市滨海地区优良的植被恢复先锋植物。     

Metals and organic components of sewage and sludges

Sewage and sludge samples were collected from rural areas of Vellore district. The metals like Cu, Zn, Cd, Pb, Fe, Ca and Mg were determined by Inductively coupled plasma atomic emission spectrophotometry (ICP-AES). For this determination HCl - HNO3 and 4N HNO3 extracts were used. The total organic carbon (TOC), chemical oxygen demand (COD) and organic matter (OM) have also been determined to evaluate the presence of organic and metallic contents in sewage and sludge environment.     

三苯基锡和五氯酚胁迫斑马鱼生理生化的影响

以斑马鱼(Brachy danio rerio)作为受试生物,分析不同暴露浓度、不同暴露时间三苯基锡(TPT)、五氯酚(PCP)对斑马鱼生理生化指标的影响,在0,1.05,2.09,4.18,6.27,8.36μg·L-1的TPT和0,5.01,10.02,20.04,40.08,80.16μg·L-1的PCP暴露下,...     

酸性硫酸盐土的景观诊断及时空分布与演替模式

酸性硫酸盐土的发育与分布存在着较大的时空变异,表现为空问分布的不连续性、发育时间的间断性、环境影响的级联性以及开发利用的风险性,因此往往给实际利用带来较大的困难。本文对酸性硫酸盐士的形成与发育特点、野外景观生态诊断以及酸性硫酸盐土的时空分布与演替模式等方面进行探讨,旨在使人们正确地认识酸性硫酸盐土,以便更有效地利用这类土地资源。     

重金属胁迫下外生菌根真菌Boletus edulis重金属积累分配与生长微环境变化

在离体培养条件下，对外生菌根真菌Boletus edulis菌丝铜镉积累分配与生长微环境变化进行研究。结果表明，铜镉胁迫下菌落直径具有相似的增长模式。与对照相比，低浓度的铜镉处理均促进了菌丝的生长，而高浓度则产生抑制作用。Boletus edulis具有很强的铜镉吸收积累能力，显示出较好的重金属耐受性。菌丝体是重金属在离体培养体系中积累的主要场所，最高处理浓度时，菌丝体内的铜镉浓度分别达到对照的26．6和28倍，而菌丝分泌物的作用相对较小。菌丝体对生物体必需元素铜和非必需元素镉具有不同的积累模式，并可根揩重金属的种类，有效地调节生长微环境，以降低重金属对菌丝体的生物有效性。这可能是外生菌根真菌的一种重金属抗性机理。     

有机无机肥配施比例对蔬菜产量和品质及土壤重金属含量的影响

关于蔬菜施有机肥和它与无机肥的合理配施比例,对蔬菜的产量和品质有重要影响,对土壤有机质和重金属含量也有影响。为控制施禽畜粪类有机肥对蔬菜的负面影响,探讨蔬菜的合理施用量和有机/无机肥配施比例,在不同质地的土壤上进行田间试验。结果表明,(1)施过量禽畜粪类有机肥对试验蔬菜产量和品质都会产生不良影响,小白菜(Brassica chinensis)和茄子(Eggplant)施禽畜粪超过22500kg/hm2、马铃薯(Solanum tuberosum L.)超过24000kg/hm2时,其产量不再增加,成活率下降,维生素C含量下降,多个试验均表现出有机肥用量增加而小白菜硝酸盐随之增加的典型特征;同时不论土壤的质地轻重,蔬菜重金属Pb有随禽畜粪用量增加而提高的趋势;在质地较轻的土壤上,蔬菜重金属Cd、As有随禽畜粪用量增加而提高的趋势;小白菜施禽畜粪肥超过7500kg/hm2、茄子和冬种马铃薯施禽畜粪肥超过75000kg/hm2,收获后土壤重金属含量高于对照和施无机肥的总Cr和As。(2)蔬菜单独施用有机肥的合适施用量,小白菜在较粘重的土壤上可施到22500kg/hm2,但有机肥与无机肥配合施用时有机肥用量可减量;茄子合适施用量应在22500kg/hm2左右;冬种马铃薯合适施用量应在24000kg/hm2左右。(3)蔬菜的有机/无机肥合理配比,小白菜、茄子、和冬种马铃薯施肥的有机氮与无机氮之比均为0.25∶1至0.5∶1时其产量和品质水平较佳。     

锑和砷对固氮菌的毒性效应及其机制研究

锑作为一种具有毒性和致癌性的类金属,其不合理的开发造成了严重的生态环境污染,尤其是土壤中高浓度锑和砷污染导致了环境中多种营养元素的缺乏。其中,氮素的缺乏严重阻碍了环境的恢复。然而,固氮微生物不仅能为氮素匮乏环境提供稳定的氮素来源,而且其固氮潜能可以作为监测土壤金属污染的敏感指标。为此,该文通过乙炔还原法(ARA)微宇宙培养试验手段,研究了不同价态锑和砷(三价及五价)在不同质量浓度(100、200、500、1 000、2 500、5 000 mg·L^-1)水平下对棕色固氮菌固氮潜能的影响,同时进一步探究了土壤固氮菌群落固氮潜能对土壤中主要锑和砷价态[Sb(Ⅴ)和As(Ⅴ)]的响应机制。结果表明,锑和砷浓度与棕色固氮菌和土壤固氮微生物的固氮潜能均呈显著负相关,验证了以固氮微生物固氮潜能作为生物指示物的可行性。此外,Sb(Ⅴ)对土壤固氮微生物的毒性显著小于As(Ⅴ)。三价锑和砷污染对固氮菌固氮潜能的毒性高于五价[As(Ⅲ)>Sb(Ⅲ)>As(Ⅴ)>Sb(Ⅴ)],这可能是由于Sb(Ⅲ)和As(Ⅲ)对细胞的致裂性强于Sb(Ⅴ)和As(Ⅴ)。相较于Sb(Ⅴ)和As(Ⅴ)对于棕色固氮菌固氮潜能的抑制作用,其对土壤固氮菌群落的固氮潜能的影响相对较弱。这一差异可能是由于土壤复杂的理化性质以及微生物群落和功能多样性而导致的。     

Regional investigations of soil and overburden analysis and plant uptake of metals

Regional studies on the bioavailability of metals at native and disturbed sites were conducted over the past seven years by the USGS. The work was concentrated in the Fort Union, Powder River, and Green River coal resource regions where measures of extractable metals in soils were found to have limited use in predicting metal levels in plants.Correlations between Cu, Fe, and Zn in plants and extractable (DTPA, EDTA, and oxalate) or total levels in native A- and C-horizons of soil were occasionally significant. A simple linear model is generally not adequate, however, in estimating element uptake by plants. Prediction capabilities were improved when a number of soil chemical and physical parameters were included as independent variables in a stepwise linear multiple regression analysis; however, never more than 54% of the total variability in the data was explained by the equations for these metals. Soil pH was the most important variable relating soil chemistry to plant chemistry. This relation was always positive and apparently a response to soil levels of metal carbonates and not Fe and Mn oxides. Studies that compared the metal uptake by rehabilitation species to extractable (DTPA) metal levels in mice soils produced similar results.     

海泡石和磷酸盐对镉铅污染稻田土壤的钝化修复效应与机理研究

采用盆栽实验,研究了海泡石、酸改性海泡石以及二者与磷酸盐联合使用对镉铅复合污染稻田土壤的钝化修复效果,并通过培养实验和重金属形态分析探讨了不同钝化剂处理的作用机理。结果表明：添加海泡石可以显著提高污染土壤pH值,而磷酸盐和改性海泡石则对土壤pH值无显著影响。钝化处理能显著降低土壤TCLP提取态Cd、Pb的质量分数,最大降低率分别可达23.3%和47.2%,钝化剂复配处理对土壤TCLP提取态重金属的抑制效果优于单一处理。施用海泡石和磷酸盐,通过提高土壤pH值、物理化学吸附以及生成矿物沉淀等作用,可以促进污染土壤中的Cd、Pb由活性高的交换态向活性低的残渣态转化,从而显著降低Cd、Pb的生物有效性和迁移能力。添加钝化剂可以显著提高水稻各部位的产量,稻谷和稻草的最大增产率分别为34.3%和26.6%;钝化剂复配处理对水稻的增产作用明显优于单一处理。施用钝化剂可以显著降低水稻各部位的Cd、Pb质量分数,最大可使精米的Cd、Pb质量分数分别降低35.8%和40.9%,钝化剂复配处理对水稻吸收Cd、Pb的抑制作用明显优于单一处理,海泡石和磷酸盐复配处理中精米的Cd、Pb质量分数符合国家食品卫生标准要求。综合分析不同钝化处理的增产作用、降低作物Cd、Pb吸收以及土壤Cd、Pb可迁移性的作用可知,海泡石与磷酸盐复配处理对稻田土壤Cd、Pb复合污染的钝化修复效果最佳。     

产油脂微藻的分离鉴定及培养条件优化

为促进自养高产油微藻的工业化应用,从青海多种生境中分离到34株产油微藻,以筛选获得产油脂最高的青3-2-2株为出发株,18S rRNA分析表明其与栅列藻属(Scenedesmus sp.)同源性达到99%以上,确定该株属于栅列藻属.研究氮源、培养时间、培养温度、初始pH值等培养条件对微藻生物量及油脂含量的影响,优化培养条件为:硝酸钠为氮源,以10%(V/V)接种量接种于普通SE培养基,培养温度为25℃,初始pH 7.0,培养周期为20 d,可以获得较高的油脂产率,比优化前的产率增加了近70%.