新型消毒剂过碳酸钠灭菌对烟草种子萌发和无菌苗生长的影响

为探索和评价新型消毒剂在植物表面灭菌中的应用方法,本研究比较过碳酸钠、次氯酸钠、升汞3种灭菌剂对烟草种子的表面灭菌效果,及对种子萌发和植株生长的影响。烟草种子分别用4.0%过碳酸钠水溶液（活性氧含量≥0.54%）处理20~40 min后直接接种于MS培养基中;33.3%次氯酸钠溶液（活性氯含量≥1.65 %）处理10 min或0.1%升汞水溶液灭菌4 min,无菌水清洗5次后接种于MS培养基中。3种方法灭菌效果相当,无污染,并且90 %的种子能萌发。过碳酸钠和次氯酸钠处理后种子萌发快、植株生长良好,且过碳酸钠灭菌组的植株生长略优;而升汞则延缓种子萌发并抑制植株生长。此外,因过碳酸钠灭菌后无需清洗,显示了其作为种子表面灭菌剂的极大优势。本研究建立了烟草种子表面灭菌的新方法,同时为其他植物的种子及外植体表面灭菌提供了参考,具有较大的实用价值。     

Co-uptake of atrazine and mercury by rice seedlings from water

The uptake of atrazine (ATR) by rice seedlings (Oryza sativa L.) from nutrient solution was investigated in the presence and absence of Hg²⁺ over a period of 96 h. Either ATR or Hg²⁺ was found phytotoxic to rice seedlings, as they inhibited the seedling growth. The seedlings showed about 50% biomass reduction when exposed to 1.0 mg/L Hg²⁺ alone in nutrient solution, and about 80% reduction when exposed to 12.0 mg/L ATR alone. Observed ATR and Hg²⁺ levels (in mg/kg) in seedlings are not related to biomass changes. When either ATR or Hg²⁺ was applied, the concentrations in seedlings increased largely in proportion to those in nutrient solution. The presence of Hg²⁺ at 0.1 and 1.0 mg/L in solution caused a small-to-moderate decline in ATR uptake by the seedlings, the effect being largely independent of the ATR concentration in nutrient solution (at 6.0 and 12.0 mg/L). The presence of ATR (at 6.0 and 12.0 mg/L) in the nutrient solution led to small-to-moderate irregular changes in the Hg²⁺ concentrations in rice seedlings. The overall results showed that there was no significant interdependence between the uptakes of ATR and Hg²⁺ by rice seedlings, which is in contrast to the enhanced ATR uptake noticed earlier with Pb²⁺ ion. Plant uptake of non-ionic organic compounds, such as ATR may be partly through water channels on the plasma membranes of plant cells.     

汞对大豆种子萌发中膜脂过氧化及体内保护系统的影响

ＨｇＣｌ２对大豆种子萌发过程中幼苗膜脂过氧化水平、细胞膜透性、保护酶（ＣＡＴ、ＳＯＤ、ＰＯＤ）活性、可溶性糖和可溶性蛋白质含量的影响进行了研究。结果表明，随着ＨｇＣｌ２浓度的升高，细胞膜脂质过氧化水平升高，细胞膜透性增大，ＣＡＴ活性降低，ＳＯＤ、ＰＯＤ活性升高，组织可溶性糖和可溶性蛋白质含量升高。     

汞对大豆种子萌发及酶活力的影响

用不同浓度ＨｇＣｌ２浸泡大豆种子，研究萌发过程的生理生化反应．结果表明，ＨｇＣｌ２能降低大豆种子活力，抑制幼苗生长和根系的发育，抑制幼苗呼吸作用及降低脂肪酸活力，但可提高大豆幼苗转氨酶及淀粉酶的活力．     

质量控制图在土壤样品砷、汞同测中的应用

[目的]保证检测结果的准确有效,实现实验室内部质量控制目标.[方法]运用原子荧光法对土壤样品中砷、汞进行了同时测定,根据实验结果绘制了质量控制图.[结果]通过对质量控制图的分析,发现检测过程失控.分析失控原因,对仪器环境条件进行了调整,检测结果受控.[结论]质量控制图在实验室内部质量控制活动中有很好的控制和预防作用.     

Influence of the pore structure of wood on moisture desorption at high relative humidities

Abstract

The influence of the porous structure on moisture desorption of two temperate and five tropical hardwoods was studied. Two experimental techniques were used to perform moisture desorption tests from full saturation at 25°C. The first one was the saturated salt solutions [between 33% and 90% relative humidity (RH)] and the second one was the pressure membrane method (above 96% RH). More emphasis was given to results obtained at high RH, given that sorption in that case is mainly governed by the capillary forces. The porous structure of these hardwoods was characterized by mercury intrusion porosimetry (MIP) and by quantitative anatomical analysis. The results showed that desorption of liquid water was very different among the hardwood species. The MIP technique appeared as an important tool to evaluate the fluid paths within wood, which permitted the prediction of water behavior in wood during drainage from full saturation at high RH. Quantitative anatomical results were very useful for explaining the first steps of drainage and mercury penetration in wood.     

汞对蚕豆根尖细胞的诱变效应

利用蚕豆根尖微核及染色体畸变技术研究了汞对植物遗传和变异的影响。试验设计了不同浓度的汞处理蚕豆根尖 ,分别统计其细胞有丝分裂情况及染色体行为。结果表明 :不同浓度汞处理对根尖细胞分裂、微核率及染色体畸变有不同程度的影响 :汞对细胞分裂影响表现为低浓度促进细胞分裂 ,高浓度抑制 ;对植物诱变性能表现为 ,较低浓度时对蚕豆根尖的毒害作用相对较弱 ,但随着浓度的增加诱变效应增强 ,毒性亦增强。     

热脱附处理技术对汞污染土壤的影响

研究温度和停留时间对含汞污染试样汞脱除率的影响，探讨不同形态汞在脱附处理过程中的浓度变化及转化规律。以青海、云南两地某氯碱生产废弃工厂汞污染土为试样，采用管式电阻炉对试样进行热脱附，使用连续浸提法提取分析7种形态汞。结果表明，从环境安全性、经济性考虑，采自青海、云南土样最佳的脱附温度和停留时间分别为 300 ℃和60 min、500 ℃和30 min。各形态汞在脱附过程中发生转化，处理后土壤中汞主要以残渣态或晶格态存在，环境风险小。     

锰改性猪粪炭对水稻吸收累积土壤中汞镉的影响

为了探明KMnO4改性猪粪炭对水稻吸收累积复合污染土壤中汞镉的阻控效果，通过盆栽试验研究添加不同量的锰改性猪粪炭（MZC）对水稻中汞镉累积分布特征、根际土壤有效态汞镉含量和土壤理化性质的影响，并探讨了MZC阻控水稻籽粒吸收累积汞镉的可能机制。结果表明：与空白对照相比，添加0.5%MZC使水稻籽粒的总汞、甲基汞和总镉含量分别降低了50.4%、58.4%和79.3%，同时降低了31.1%和39.9%根际土壤有效态汞和镉的含量，但增加了70.3%根际土壤总Mn含量；且添加0.5%的原始猪粪炭对水稻籽粒中总汞、甲基汞和镉含量的降幅显著小于锰改性猪粪炭的，表明经过KMnO4改性可以显著增强猪粪炭对土壤汞镉的钝化能力。水稻籽粒、茎叶中的汞镉含量和根际土壤有效态汞镉含量都随着MZC添加量的增加呈明显的降低趋势。统计分析显示水稻籽粒和茎叶中的汞镉含量与根际土壤中有效态汞、镉呈显著正相关性，而土壤中有效态汞镉含量与土壤的pH、CEC呈负相关。添加MZC使土壤pH、CEC升高，降低了根际土壤中汞、镉的生物有效性，从而减少了水稻地上部分对汞镉的吸收累积。因此，锰改性猪粪炭是一种具有应用潜力的能保障汞镉复合污染农田水稻安全生产的土壤修复剂。     

贵州务川汞矿区土壤丛枝菌根真菌多样性研究

对贵州务川汞矿区不同水平汞污染植物根际土壤丛枝菌根(Arbuscular Mycorrhizal,AM)真菌资源分布及多样性进行分析，结果发现：本研究选取的务川汞矿区3个样地土壤汞含量在94.1～268.0 mg/kg，远高于国家规定的土壤汞含量，汞污染极其严重。随着汞含量增加，AM真菌侵染率、孢子密度显著降低，AM真菌群落丰富度、多样性及均匀度均有所降低，但差异未达显著水平，而仍有部分对汞污染耐受性较强的AM真菌有较高的分布。另外，管柄囊霉属AM真菌在5个样品中均有较高丰度，球囊霉属AM真菌在火棘根际的相对丰度随着汞含量升高而升高，因此，火棘–管柄囊霉属AM真菌或火棘–球囊霉属AM真菌联合进行汞污染修复，有一定的应用价值。