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1.
《广西农业生物科学》2011,30(1):102-102
Bt Research (ISSN 1925-1939) is a new launched, open access and peer-reviewed journal that disseminates significant creative reviews and opinions or  相似文献   

2.
Molecular Pathogens (ISSN 1925-1998) is an open access, peer reviewedjournal, and publishes and disseminates outstanding original achievements thatsignificantly advance the understanding of molecular pathogens.  相似文献   

3.
《广西农业生物科学》2011,30(1):116-116
Molecular Entomology (ME, ISSN 1925-198X) is an international open access and peer reviewed journal, publishing original research papers within the broadest bounds of molecular entomology.  相似文献   

4.
GMO Biosafety Research (ISSN 1925-1955) is a new launched, open access and peer-reviewed journal that dedicates to publish the release of genetically modified organisms (GMOs), GMO safety,  相似文献   

5.
Soils were collected from 2-year (2-y) and 3-year (3-y) old red-pine seedling plots in two tree nurseries, Hayward in the north and Wilson in the southwestern part of Wisconsin State respectively, and equilibrated with 0.01 M Ca(NO3)2 for soil solution Zn and Mn (solu-Zn and Mn), and with 0.01 M Ca(NO3)2+0.005 M EDTA for soil adsorbed Zn and Mn (ad-Zn and Mn). Buffering capacity of soil Zn and Mn (b-Zn and Mn) was obtained from the ratio of ad-Zn and Mn to the solu-Zn and Mn. The concerned traces in pine seedling needles (ndls), stems(sts) and roots (rts) were simultaneously measured.  相似文献   

6.
A rhizobox experiment was conducted to compare iron (Fe) oxidation and changes of pH, redox potential (Eh) and fractions of zinc (Zn) and lead (Pb) in rhizosphere and non-rhizosphere soils of four emergent-rooted wetland plants (Echinodorus macrophyllus, Eleocharis geniculata, Hydrocotyle vulgaris and Veronica serpyllifolia) with different radial oxygen loss (ROL) from roots. The results indicated that all these wetland plants decreased pH and concentration of Fe(Ⅱ) but increased the Eh in the rhizosphere soils. Pb and Zn were transformed from unstable fractions to more stable fractions in the rhizosphere soils, so decreasing their potential metal mobility factors (MF). Among the four plants, E. macrophyllus, with the highest ROL and root biomass, possessed the greatest ability in formation of Fe plaque and in the reduction of heavy metal MFs in the rhizosphere soil. Wetland plants, with higher ROLs and root biomass, may thus be effective in decreasing potential long-term heavy metal bioavailabilities.  相似文献   

7.
巴基斯坦白沙瓦市铅和镉在不同路旁土壤及植物中的污染   总被引:1,自引:0,他引:1  
S. KHAN  M. A. KHAN  S. REHMAN 《土壤圈》2011,21(3):351-357
Soil and plant samples were collected from roadside sites (along with primary, secondary and tertiary roads) and reference site to investigate the contamination of soils and old common plant species with lead (Pb) and cadmium (Cd) in Peshawar City, Pakistan. All the data were analyzed using ANOVA analysis that showed a significant (P ≤ 0.01) variation in Pb and Cd concentrations in the roadside soils and plants as compared to the reference site. The mean concentrations of Pb and Cd were 53.9 and 6.0 mg kg-1 in soils and 49.1 and 10.9 mg kg-1 in plants, respectively. Significant variation (P ≤ 0.01) in concentrations of Pb and Cd in soil and plant samples along with primary, secondary and tertiary roads might be due to different traffic densities. The highest value (9.4) of metal accumulation index (MAI) was observed for Eucalyptus camaldulensis. In selected plant species, the Pb and Cd accumulation was found in the order of E. camaldulensis > Ficus elastica > Dalbergia sissoo > Alstonia scholaris. The roadside soils and plants were highly contaminated with Pb and Cd as compared to the reference site.  相似文献   

8.
A rhizobox experiment was conducted to compare iron (Fe) oxidation and changes of pH, redox potential (Eh) and fractions of zinc (Zn) and lead (Pb) in rhizosphere and non-rhizosphere soils of four emergent-rooted wetland plants (Echinodorus macrophyllus, Eleocharis geniculata, Hydrocotyle vulgaris and Veronica serpyllifolia) with different radial oxygen loss (ROL) from roots. The results indicated that all these wetland plants decreased pH and concentration of Fe(Ⅱ) but increased the Eh in the rhizosphere soils. Pb and Zn were transformed from unstable fractions to more stable fractions in the rhizosphere soils, so decreasing their potential metal mobility factors (MF). Among the four plants, E. macrophyllus, with the highest ROL and root biomass, possessed the greatest ability in formation of Fe plaque and in the reduction of heavy metal MFs in the rhizosphere soil. Wetland plants, with higher ROLs and root biomass, may thus be effective in decreasing potential long-term heavy metal bioavailabilities.  相似文献   

9.
百喜草覆盖和敷盖对中国南方红壤坡地径流和产沙的影响   总被引:3,自引:0,他引:3  
Rainfall,runoff (surface runoff,interflow and groundwater runoff) and soil loss from 5 m × 15 m plots were recorded for 5 years (2001-2005) in an experiment with three treatments (cover,mulch and bare ground) on sloping red soil in southern China.Surface runoff and erosion from the Bahia grass (Paspalum notatum Flugge) cover plot (A) and mulch plot (B) during the 5 years were low,despite the occurrence of potentially erosive rains.In contrast,the bare plot (C) had both the highest surface runoff coefficient and the highest sediment yield.There were significant differences in interflow and surface runoff and no significant difference in groundwater runoff among plots.The runoff coefficients and duration of interflow and groundwater runoff were in the order plot B > plot A > plot C.Effects of Bahia grass cover were excellent,indicating that the use of Bahia grass cover can be a simple and feasible practice for soil and water conservation on sloping red soil in the region.  相似文献   

10.
A hydroponics experiment was conducted to evaluate the role of potassium (K) and silicon (Si) in mitigating the deleterious effects of NaCl on sugarcane genotypes differing in salt tolerance. Two salt-sensitive (CPF 243 and SPF 213) and two salt-tolerant (HSF 240 and CP 77-400) sugarcane genotypes were grown for six weeks in ? strength Johnson’s nutrient solution. The nutrient solution was salinized by two NaCl levels (0 and 100 mmol L-1 NaCl) and supplied with two levels of K (0 and 3 mmol L-1) and Si (0 and 2 mmol L-1). Applied NaCl enhanced Na+ concentration in plant tissues and significantly (P ≤ 0.05) reduced shoot and root dry matter in four sugarcane genotypes. However, the magnitude of reduction was much greater in salt-sensitive genotypes than salt-tolerant genotypes. The salts interfered with the absorption of K+ and Ca2+ and significantly (P ≤ 0.05) decreased their uptake in sugarcane genotypes. Addition of K and Si either alone or in combination significantly (P ≤ 0.05) inhibited the uptake and transport of Na+ from roots to shoots and improved dry matter yields under NaCl conditions. Potassium uptake, K+/Na+ ratios, and Ca2+ and Si uptake were also significantly (P ≤ 0.05) increased by the addition of K and/or Si to the root medium. In this study, K and Si-enhanced salt tolerance in sugarcane genotypes was ascribed to decreased Na+ concentration and increased K+ with a resultant improvement in K+/Na+ ratio, which is a good indicator to assess plant tolerance to salt stress. However, further verification of these results is warranted under field conditions.  相似文献   

11.
针对持久性有机污染物在水生生物体内易于积累的特性,利用气相色谱与质谱联用技术(GC-MS),检测了白洋淀8种鱼类体内多氯联苯(PCBs)含量,并分析了同系物组成特征。根据白洋淀鱼类检测到同系物情况,计算毒性当量(TEQ)并进行评价。白洋淀8种鱼类体内PCBs平均含量范围是55.85~1 485.74 ng.g-1脂肪重,从高到低的顺序依次为黄颡〉黄鳝〉乌鳢〉泥鳅〉鲤鱼〉鳙鱼〉鲫鱼〉鲇鱼。在8种鱼类PCB同系物组成中,四氯联苯和五氯联苯是主要的同系物,其相对百分含量为52.0%~84.3%。这种组成模式反映了白洋淀地区有多氯联苯工业品的使用历史。8种鱼类体内PCBs的毒性当量(TEQ)范围是0.09~1 412.87 pg TEQ.g-1脂肪重,其大小顺序依次为鳙鱼〉鲫鱼〉鲇鱼〉黄颡〉黄鳝〉鲤鱼〉乌鳢〉泥鳅。结果表明,白洋淀淀区部分鱼类已经受到PCBs一定程度的污染,应引起重视。  相似文献   

12.
为更好地揭示养殖系统的磷收支和污染程度,以上海郊区3口团头鲂(Megalobrama amblycephala)混养鱼塘即池塘A、B、C以及水源D为研究对象,定期测定养殖期间水体中总磷(TP)、活性磷酸盐(PO4-P)以及沉积物中总磷的含量,并探究沉积物中不同形态磷,包括交换态磷(Ex-P)、铝结合磷(Al-P)、铁结合磷(Fe-P)、闭蓄态磷(Oc-P)、原生碎屑磷(De-P)、钙结合磷(Ca-P)和有机磷(Or-P)的分布变化特征。试验发现,该养殖场水源水TP(0.17±0.06)mg·L-1及PO4-P(0.11±0.06)mg·L-1含量一直维持在稳定的较低水平,养殖生产导致池塘A、B、C水中TP大大增加,已超过地表水Ⅲ类标准和淡水养殖池塘排放标准(Ⅱ类)。养殖池塘及水源沉积物中TP浓度分别是(0.69±0.04)、(0.70±0.07)、(0.68±0.09)、(0.79±0.13)mg·g-1,池塘表层沉积物中TP含量变化不大,而水源沉积物TP变化波动性明显。池塘表层沉积物中磷主要由Fe-P(18.03±6.01)%、Oc-P(22.82±5.34)%、Ca-P(27.48±8.15)%和Or-P(20.29±6.60)%组成,Ex-P(3.07±1.06)%、Al-P(7.62±3.11)%,尤其是De-P(0.69±0.35)%  相似文献   

13.
三峡库区有限顺坡耕作坡耕地表土颗粒分形特征   总被引:2,自引:0,他引:2  
在三峡库区忠县境内选择水平沟模式、埂坎模式、地埂植物篱模式以及无措施的4种典型坡耕地采集了48个表土(0 ~ 20 cm)样本,利用分形维数研究不同模式有限顺坡耕作坡耕地的表土颗粒组成、分形特征及相互关系.结果表明:4种模式坡耕地土壤颗粒黏粒体积分数均较低(均值8.03%~11.47%),粉粒较高(均值62.39%~83.24%).无措施、水平沟模式、埂坎模式坡耕地的砂粒体积分数为22.95% ~29.58%,而地埂植物篱模式坡耕地的砂粒均值仅5.29%.4种模式坡耕地表土的粒径体积分形维数分别为无措施2.579 ~ 2.708、水平沟模式2.603~2.706、埂坎模式2.581 ~2.701、地埂植物篱模式2.610~2.827.粒径分形维数均值表现为地埂植物篱模式(2.737)>水平沟模式(2.674)>埂坎模式(2.659)>无措施坡耕地(2.654).4种模式坡耕地表土的粒径分形维数与黏粒(<0.002 mm)体积分数呈显著的线性正相关关系,与砂粒(>0.05 mm)体积分数呈显著的线性负相关关系;但与粉粒(0.002 ~0.05 mm)体积分数线性关系差异较大.其中,无措施、水平沟模式、埂坎模式呈显著的线性正相关关系,而地埂植物篱模式二者相关性不显著.  相似文献   

14.
以黑曲霉(Aspergillus niger)为实验菌株,探讨不同pH值、重金属离子初始浓度、孢子液接种量和重金属离子共存对菌体生长量和富集能力的影响。结果表明:Cu(Ⅱ)和Zn(Ⅱ)对黑曲霉的最低抑菌浓度分别为250、700mg·L-1;菌株最佳生长和富集条件为pH5.0、孢子液体积1mL,黑曲霉对Cu(Ⅱ)和Zn(Ⅱ)的富集分别在4d和5d达到平衡。在重金属共存系统中,Cu(Ⅱ)/Zn(Ⅱ)浓度越高,黑曲霉对Cu(Ⅱ)/Zn(Ⅱ)富集能力越强;Cu(Ⅱ)和Zn(Ⅱ)的富集量分别在其浓度为150、250mg·L-1时达到最大(8.89、22.80mg·g-1)。采用扫描和透射电镜观察富集前后菌体表面形态和内部结构变化,表明菌体生长受重金属毒害作用可能破坏菌丝表面结构,A.niger富集Cu(Ⅱ)和Zn(Ⅱ)由表面吸附和胞内富集两部分组成,Zn(Ⅱ)作用下菌丝的完整性较好,菌株对Zn(Ⅱ)具有较强的抗性和适应能力。  相似文献   

15.
为了解镉胁迫下外源NO对地被植物生理响应的调控机制,采用盆栽试验研究了外源NO(SNP)对镉胁迫下长春花幼苗生长、活性氧代谢、质膜ATP酶活性及光合特性的影响。结果表明,外施100μmol·L^-1SNP能缓解25mg·kg一镉胁迫对长春花幼苗生长的抑制,增加叶长、叶宽、株高、基径和生物量。与镉胁迫相比,施用SNP能够降低叶片和根系中丙二醛(MDA)、过氧化氢(H2O2)含量和过氧根离子自由基(O2^-·)产生速率,提高过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性及还原型谷胱甘肽(GSH)含量。SNP能显著缓解镉胁迫对叶绿素a(Chla)、叶绿素b(Chlb)和总叶绿素的抑制,提高叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和气孔限制值(Ls),降低胞间CO2浓度(G)和瞬时光能利用效率(LUE)。同时,外源NO能诱导叶片和根系中质膜H+-ATPase和Ca2+-ATPase活性提升到正常水平(对照)。但外施100μmol·L-1 NO分解产物NaNOx或SNP相似物Na3Fe(CN)6对镉胁迫则无明显缓解作用。因此,外源NO可通过提高活性氧清除能力,增加叶绿素含量,增强质膜ATP酶活性,从而提高叶肉细胞光合能力,加强离子跨膜运输和信号转导,缓解镉胁迫对细胞质膜的损伤。  相似文献   

16.
冬前积温对河南省小麦冬前生长发育的影响   总被引:4,自引:0,他引:4  
为了给播期调整和提高自然资源利用率提供科学依据,在大田试验条件下,以3个半冬性和3个弱春性小麦品种为供试材料,对冬前积温为350~900℃.d范围内的小麦冬前生长发育进行了分析。结果得出:①播种-出苗的天数和所需积温随着冬前积温的降低而增加,冬前积温每降低100℃.d,播种-出苗天数约增加0.7d,所需积温约增加3.7℃.d(半冬性)或2.5℃.d(弱春性);②冬前积温与冬前主茎叶龄和冬前每叶积温均呈显著正相关(P0.01),冬前积温每降低100℃.d,冬前主茎叶龄约减少0.9片(半冬性)或1.0片(弱春性),每叶积温减少5.0℃.d左右;③随冬前积温的降低,幼穗分化进入单棱期和二棱期的时间推迟,单棱期持续天数增加而二棱期持续天数减少,冬前积温每降低100℃.d,单棱期平均增加10.0d(半冬性)或12.9d(弱春性),二棱期平均减少15.5d(半冬性)或17.4d(弱春性)。结论为,符合冬前壮苗叶龄指标的适宜冬前积温为550~750℃.d(半冬性)和450~600℃.d(弱春性),保证小麦以二棱期安全越冬的适宜冬前积温为650~800℃.d(半冬性)和550~700℃.d(弱春性),从叶龄指标和安全越冬两方面考虑,河南省小麦适宜冬前积温范围为650~750℃.d(半冬性)和550~600℃.d(弱春性)。  相似文献   

17.
采用开顶式气室(OTC),对水稻“3694繁”(Oryza sativa L.3694 Fan)进行田间原位臭氧(O3)熏气实验,研究了不同O3浓度熏气处理下水稻光合色素、气体交换参数以及产量的响应。实验设置分4个水平:过滤大气组(CF,10 nL.L^-1)、自然大气组(NF,40nL.L^-1)和两个不同浓度的O3处理组(O1:100 nL.L^-1;O2:150 nL.L^-1)。结果表明:(1)与CF组相比,两个不同浓度的O3处理均导致水稻叶片光合色素含量大幅度下降,加速水稻的衰老过程;(2)在实验进程中,O3处理导致水稻叶片气体交换参数发生显著变化,饱和CO2浓度的净光合速率(Psa)t、气孔导度(Gs)、水分利用效率(WUE)、气孔限制值(Ls)和羧化效率(CE)均呈现下降趋势,表明O3浓度的升高使水稻光合作用对CO2的利用效率降低,水稻在灌浆期对O3最为敏感;(3)O3处理使水稻产量损失明显,当AOT40值达到2.32μL.L^-1h时,就能导致水稻产量10%的减产。  相似文献   

18.
以重金属Cr(Ⅵ)为目标污染物,在两种实验条件下(实验柱Ⅰ为模拟污染水样,实验柱Ⅱ为实际污染水样)考察了壳聚糖稳定纳米铁对Cr(Ⅵ)的去除能力。实验柱Ⅰ和实验柱Ⅱ分别在第160PV和127PV时发生了击穿效应。与实验柱Ⅰ相比,实验柱Ⅱ中壳聚糖稳定纳米铁对Cr(VI)的去除能力降低了25%。SEM表征显示,实验柱Ⅱ中壳聚糖稳定纳米铁的表面形成了许多葡萄状晶体,它们的存在导致实验柱Ⅱ中纳米铁的去除能力明显低于实验柱Ⅰ。XPS表征显示,由于Ca和Mg的氢氧化物替代了部分铁氢氧化物,导致实验柱Ⅱ中壳聚糖稳定纳米铁表面Fe原子的相对含量低于实验柱Ⅰ。Cr元素高分辨率XPS能谱分析显示,在实验柱Ⅰ的条件下CKVI)被还原得更充分,而且在两种实验条件下都有部分Cr(VI)被吸附在纳米铁表面最终没有被零价铁所还原。  相似文献   

19.
本研究针对北京郊区汇源与正谷有机蔬菜基地,通过对不同蔬菜生产基地取样分析,研究有机和常规蔬菜生产条件下土壤养分平衡特征,分析有机生产蔬菜和土壤的15N特征。结果表明,(1)有机蔬菜生产与常规生产对比,由于施肥数量不同,汇源有机蔬菜基地土壤N、P及K盈余量(分别为356~472kg·hm-2、298kg·hm-2和200~226kg·hm-2)高于当地常规生产,而正谷有机蔬菜生产土壤N、P及K养分盈余量(分别为-164~190kg·hm-2、107.9~435.5kg·hm-2和-164.5~-136.8kg·hm-2)低于当地常规生产;(2)汇源有机蔬菜生产模式中,土壤N素养分有逐季累积的趋势,有机肥的N、P和K养分存在着不平衡性,这可能是造成0~20cm土层磷素大量累积的重要原因;(3)蔬菜类别不同,δ15N值不同,一般为叶菜类最高(10.49‰),果菜类次之(10.07‰),根菜类δ15N值最低(5.62‰);(4)植物不同部位δ15N值也有差异。针对圆椒的分析表明,圆椒叶δ15N(12.44‰)〉圆椒果实δ15N(9.35‰);(5)土壤δ15N与土壤全N之间有一定的相关性,回归方程为δ15N土壤=13.098N土壤+3.7624,R2=0.938,而植物δ15N与土壤δ15N之间、植物δ15N与土壤全氮相关性较差。长期施用有机肥,使得土壤中15N更多来自有机肥,进而表现为蔬菜δ15N升高,高量有机肥可以短期内增加叶菜类植物δ15N值。  相似文献   

20.
通过盆栽试验,研究了超富集植物李氏禾根系对Cr(Ⅵ)的吸收特征。结果表明,解偶联剂2,4-二硝基苯酚(DNP),ATP酶抑制剂(Na3VO4)和低温(2℃)处理均显著地抑制了李氏禾根对Cr(Ⅵ)的吸收(P〈0.05).其中,低温处理的抑制作用最明显,李氏禾根中铬的浓度较对照降低69.8%,说明李氏禾根对Cr(Ⅵ)的吸收是需要能量的主动过程。此外,李氏禾根系对Cr(Ⅵ)的吸收符合Michaelis-Menten方程,其米氏常数(k)为91.08μmol·L-1。在5mmol·L^-1SO4^2-处理下,该米氏常数是对照的1.27倍;而在SO4^2-缺失的条件下,李氏禾根对Cr(Ⅵ)吸收的米氏常数较对照减少了24.3%。这种拮抗关系表明李氏禾根对Cr(Ⅵ)的吸收可能与硫酸根吸收体系有关。  相似文献   

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