对巴东县野三关镇12个采样点进行调查,研究大蒜(Allium sativum L.)样品的土壤及其大蒜各部位的富硒性.结果 表明,12个采样点的土壤、蒜瓣、蒜薹、蒜叶的硒含量分别为0.083～2.676 mg/kg、0.054～0.589 mg/kg、0.038～0.257 mg/k g、0.033～0.152 mg/kg;不同土壤采样点,大蒜的蒜瓣、蒜薹、蒜叶硒含量均有差异;每个处理的蒜瓣对硒的富集性最强,大蒜各部位对硒的富集性强弱表现为蒜瓣＞蒜薹＞蒜叶.

喷施叶面硒肥是提高水稻籽粒硒含量的有效措施.通过对杂交水稻隆两优华占在孕穗期施用不同浓度的硒叶面肥,研究了施硒对水稻外观品质及籽粒硒、镉和砷含量的影响.结果 表明:①施硒能显著提高水稻的整精米率,降低垩白度,当施用量为23 g/hm2复合硒叶面肥+20 g/hm2亚硒酸钠时,整精米率达到最高值65.67％,垩白度达到最低值0.65％;②增施硒肥能增加水稻精米和糙米的硒含量,当施用量为23 g/hm2硒叶面肥+30 g/hm2亚硒酸钠时,水稻精米和糙米硒含量分别达到最大值为0.784 3 mg/kg和0.816 7 mg/kg,糙米积累硒的能力高于精米;③增施硒肥对水稻精米和糙米中镉和砷含量均没有显著影响,表明籽粒对硒与镉和砷的吸收没有协同作用.同一处理下糙米镉含量均高于精米镉含量,但差异不显著,糙米对重金属砷的累积效果均显著高于精米.

Composites containing silver halide nanoparticles have attracted great interest as potential antibacterial materials. Ag Cl nanoparticles were synthesized in W/O microemulsion using octylphenylpolyethylene glycol(OP) as the emulsifier and methyl methacrylate(MMA) as the oil phase. Ag Cl/PMMA complex latex was prepared via in situ microemulsion polymerization. Effects of surfactant(cOP) and salt(csalt) concentration on the formation and morphology of Ag Cl nanoparticles were studied by ultraviolet-visible spectrum and transmission electron microscopy(TEM). Furthermore, the antibacterial effect of Ag Cl/PMMA latex was evaluated against E. coli. The results show that the Ag Cl nanoparticles prepared were spherical with a mean diameter of about 5 nm. The increase of cOP and csalt promotes the formation of Ag Cl nanoparticles with smaller diameter in the W/O microemulsion, which provide the Ag Cl/PMMA latex good antibacterial activity. This simple and mild preparation method can be easily applied in an industrial scale process. Therefore, the Ag Cl/PMMA latex prepared is a novel antibacterial latex with great potentially applications.

Treated with 3 kinds of cultivation mediums:peat,moss and soil,adaptability of Thalia dealbata,Pontederia cordata,Iris sanguinea and Hydrocotyle verticillata were compared.The results showed that:both the above part's and root system's biomass values of Thalia dealbata,Pontederia cordata and Hydrocotyle verticillata which were cultivated with soil are better than those of the other two treatments.The root/shoot ratios of plants which were cultivated in peat or moss are higher than those cultivated in soil.The adaptability of Iris sanguinea presented no obvious difference under 3 different treatments.In the 3 treatments,the variation tendency of root's active absorbing area's percentage of 4 water-plants were similar,bascially fluctuating between 40%～50% without obvious differences.4 kinds of water-plants all had some adaptability cultivated whether in peat or moss mediums.

The influence of soil sorption of diuron on its toxicity to zebrafish embryos was investigated.Results showed that the sorption of diuron by soil occurred via a partition process,with a log Koc of 2.19.Diuron was moderately toxic to zebrafish embryos.From the observed hatching rates of embryos,the calculated EC50 value of diuron in soil-free solutions following a 72h exposure was 4.99 mg/L,along with a strong teratogenesis.Soil sorption effectively reduced the solution-phase concentrations of diuron in soil-water systems.Based on the total concentrations of diuron in soil-water systems,soil sorption increased the EC50 value of diuron to 7.53 mg/L.In comparison,the solution-phase concentration-based EC50 value of diuron was 4.75 mg/L,similar to the EC50 value obtained using soil-free solutions.It could be concluded that the soil sorption effectively reduced the toxicity of diuron to zebrafish embryos,and sorbed diuron virtually lost its toxicity.

This paper reviewed the advances in container seedling production with respect to the characteristics and selection of container medium,fertilization control and nutrient loss and various additives,etc.

总结近年来水生植物在杭州西湖风景区的应用现状,分析了目前水生植物应用和造景的主要存在问题,提出搭建园林建设管理、园林设计与水生植物生产者之间的交流平台,为今后水生植物园林应用的良性发展奠定基础.

采用溶液培养方法研究了不同供氮水平对菠菜生物量、硝酸盐和不同形态草酸含量的影响.结果表明,供氮水平由4 mmol/L增加到8 mmol/L,菠菜产量显著增加,继续提高氮水平对产量没有显著影响.叶片中的维生素C(Vc)含量随着供氮浓度从4 mmol/L提高到8 mmol/L而显著增加,再增加氮水平,叶片中的Vc含量明显下降;而菠菜叶柄Vc的含量则随供氮水平的提高显著下降.叶片硝酸盐含量随着氮浓度的提高而增加,当供氮水平由4mmol/L增加到8 mmol/L时,叶柄硝酸盐含量显著下降,而氮水平由8 mmol/L提高到20 mmol/L时,叶柄硝酸盐含量则随之升高.供氮浓度从4 mmol/L增加到8 mmol/L,叶片可溶态草酸含量略有下降,再提高供氮水平则明显上升,供氮水平低于12 mmol/L时,叶柄中的可溶态草酸和菠菜叶片和叶柄中的草酸总量则随着氮水平的提高而升高,高于12 mmol/L草酸含量反而降低.由此可见,菠菜在供氮浓度为8mmol/L(N2)时能够获得较高的产量和Vc含量,较低的硝酸盐和草酸含量,表明适宜的供氮水平下可获得高产优质的菠菜.