Reduced Germination and Seedling Vigor of Weeds with Root Extracts of Maize and Soybean,and the Mechanism Defined as Allelopathic

Journal of Crop Science and Biotechnology - Due to the negative consequences of synthetic herbicides use and their reducing effectiveness due to development of resistant weeds, promotion of...     

极小种群植物“川柿”生物学特性及种子萌发方法研究

摘 要：【目的】为了保护和发展极小种群植物川柿，开展此研究。【方法】采用观测法，连续3年对其生物学特性研究；种子萌发方法：（1）后熟0、30、45、60天，剥离清洗播种；（2）后熟60天，以GA300、600、1000 mg/L溶液浸种1h；播种基质为河沙（保持一定湿度），放置室内，统计萌发时间和出苗率。【结果】（1）川柿花期4-5月，10月为果熟期，单果直径32.7±5.80mm，单果重23.0±5.30g；种子肾形、千粒重1070g；成年植株呈隔年开花、结果现象；（2）种子经“后熟+河沙播种”，可萌发，其中以后熟60天的出苗率较高，为65%；直接播种种子，出苗率5%；“后熟+GA溶液浸种+河沙播种”，出苗率均高于65%，其中以GA600mg/L浸泡1h处理，出苗率最高为83.3%。【结论】极小种群植物川柿为常绿叶乔木，有隔年开花、结果现象； “果后熟60天+GA600mg/L浸泡种子1h +室内河沙播种”可提高种子萌发率，为川柿种子繁殖提供参考。     

轮叶狐尾藻对水体重金属铅污染的耐性研究

以狐尾藻(Myriophyllum verticillatum)为试验材料,采用液体培养法,研究了不同浓度Pb尾矿液单一胁迫下对其幼苗生长及生理指标的影响,以期为今后在探讨狐尾藻对Pb耐性机理方面提供参考依据和实践指导。结果表明:随着Pb尾矿渗出液单位浓度的升高,狐尾藻幼苗的株高和根长以及干质量整体呈不断下降趋势,其中,在100%Pb尾矿液处理下地下部的干质量较对照下降显著(P0.05)。此时,地上部干质量较对照也呈下降趋势,但整体幅度不大,说明狐尾藻幼苗的生长整体受到明显抑制;随着Pb尾矿渗出液单位浓度的升高,幼苗中光合色素含量逐渐下降且整体均低于对照。在纯Pb尾矿液处理条件下,Chla、Chlb和Car的含量比对照下降了14.6%、29.6%和23.2%;所有处理中幼苗地下及地上部相对电导率与Pb尾矿液浓度成正比且均高于对照。各个处理的地上及地下部Pro含量随着Pb尾矿液浓度增高整体呈上升趋势。其地上和地下部的AsA含量和GSH含量变化呈低浓度上升,高浓度下降的趋势。在25%Pb胁迫处理下,幼苗中AsA含量在地上和地下部均达到最高,与对照相比差异明显(P0.05),较对照增加了93.5%和89.8%。而地上和地下部GSH含量较对照增加了35.7%、4.36%。数据表明,狐尾藻对Pb胁迫下的环境有一定的抗性,可被用于Pb污染环境的生态修复。     

Preparation and properties of solid polymer electrolyte based on imidazolium-based ionic liquids for structural capacitors

We prepared solid polymer electrolytes (SPEs) composed of poly(ethylene glycol) monomethyl ether acrylate (1A9OMe) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIm][OTF]) and 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide ([EMIm][TFSI]) as the ionic liquid. The SPEs formed by appropriately adding ionic liquids in the 1A9OMe prior to thermal cure. The ratio of 1A9OMe and ionic liquid was 1:9, 3:7, and 5:5, respectively. The characterization of solid polymer electrolytes were investigated using Fourier transform infrared spectroscopy in the attenuated total reflectance mode (FTIR-ATR), Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and glavanostatic charge-discharge test. The highest ionic conductivity of SPEs was found to be 4.90×10^?4 S/cm in a 1A9OMe/[EMIm][OTF] of 3:7. As IL contents were increased, the specific capacitance of supercapacitor was increased. The specific capacitance of supercapacitor for ionic liquid with large ion size was lower than that for ionic liquid with smaller ion size.     

Plant species identification using fecal DNAs from red-eared slider and Reeves’ pond turtle in agricultural canals for rural ecosystem conservation

Fecal DNA samples from the red-eared slider and Reeves’ pond turtle, suspected pests of lotus root paddies, were used to identify the plant species eaten by these turtles in order to develop a strategy for rural ecosystem conservation. The fecal samples were obtained from young and adult individuals (mostly female) of both species living in agricultural canals surrounding lotus root paddies in Tokushima Prefecture, Japan. The samples were screened for the presence or absence of DNA from nine plant species using PCR and plant species-specific primers for the rbcL gene of chloroplast DNA. In the red-eared slider, our analysis identified seven plant species in the fecal DNA samples of adults and three plant species in those of young individuals. In Reeves’ pond turtle, our analysis identified two plant species from adult fecal samples and one species from those of young individuals. Thus, adult red-eared sliders consume a greater range of plants than young red-eared sliders or Reeves’ pond turtles. Both turtle species, independently of age, consumed lotus plants and were likely to cause feeding damage to lotus roots. Considering the plant species detected in adult red-eared sliders and these plant habitats, we suggest that this adult turtle is likely to travel between the agricultural canals and the lotus root paddies. These findings will help the development of strategies for preventing damage to lotus roots by these turtles; furthermore, they indicate that fecal DNA analysis will be applicable to investigation of the feeding habits of other animal species.     

Vole abundance and reindeer carcasses determine breeding activity of Arctic foxes in low Arctic Yamal,Russia

Background

High latitude ecosystems are at present changing rapidly under the influence of climate warming, and specialized Arctic species at the southern margin of the Arctic may be particularly affected. The Arctic fox (Vulpes lagopus), a small mammalian predator endemic to northern tundra areas, is able to exploit different resources in the context of varying tundra ecosystems. Although generally widespread, it is critically endangered in subarctic Fennoscandia, where a fading out of the characteristic lemming cycles and competition with abundant red foxes have been identified as main threats. We studied an Arctic fox population at the Erkuta Tundra Monitoring site in low Arctic Yamal (Russia) during 10 years in order to determine which resources support the breeding activity in this population. In the study area, lemmings have been rare during the last 15 years and red foxes are nearly absent, creating an interesting contrast to the situation in Fennoscandia.

Results

Arctic fox was breeding in nine of the 10 years of the study. The number of active dens was on average 2.6 (range 0–6) per 100 km² and increased with small rodent abundance. It was also higher after winters with many reindeer carcasses, which occurred when mortality was unusually high due to icy pastures following rain-on-snow events. Average litter size was 5.2 (SD = 2.1). Scat dissection suggested that small rodents (mostly Microtus spp.) were the most important prey category. Prey remains observed at dens show that birds, notably waterfowl, were also an important resource in summer.

Conclusions

The Arctic fox in southern Yamal, which is part of a species-rich low Arctic food web, seems at present able to cope with a state shift of the small rodent community from high amplitude cyclicity with lemming dominated peaks, to a vole community with low amplitude fluctuations. The estimated breeding parameters characterized the population as intermediate between the lemming fox and the coastal fox ecotype. Only continued ecosystem-based monitoring will reveal their fate in a changing tundra ecosystem.

     

<Emphasis Type="Italic">Lupinus albus</Emphasis> Conglutin Gamma Modifies the Gene Expressions of Enzymes Involved in Glucose Hepatic Production <Emphasis Type="Italic">In Vivo</Emphasis>

Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders.     

Application of silver nanoparticles as an antibacterial mordant in wool natural dyeing: Synthesis,antibacterial activity,and color characteristics

Madder is a natural colorant which is commonly applied with metal salts as a mordant to improve its affinity to fibers and color fastness. Madder produces an insoluble complex or lake in the presence of metal ions on mordanted fabric. In this study, wool fabric was pretreated with AgNPs (silver nanoparticles) as a mordant, then dyed with madder. The wool fabric samples were examined by scanning electron microscopy (SEM) and their colorimetric characteristics were evaluated. The formation of spherical silver nanoparticle was confirmed using UV-Visible spectroscopy, SEM images, and elemental analysis. The average size of synthesized silver nanoparticles on the surface of wool fibers is around 73 nm. The dyed wool samples were pretreated with different concentration of Ag⁺ ions or AgNPs, which showed higher color strength value compared to untreated dyed wool fabric. This pretreatment also presented good antibacterial activity.     

氨唑草酮的水解、挥发及其在水-沉积物系统中的降解特性

为评价氨唑草酮的环境安全性,参照国家标准GB/T 31270-2014的要求,采用室内模拟法研究了氨唑草酮在不同温度和不同pH值缓冲溶液中的水解特性、在不同环境介质中的挥发特性,以及在2种水-沉积物系统中的降解特性。结果表明:氨唑草酮在25 ℃时,在pH值为4或7的缓冲液中水解半衰期均长于365 d,在pH值为9的缓冲液中水解半衰期为90.0 d,属于难水解至中等水解农药。在20~25 ℃、气体流速500 mL·min^-1的条件下,氨唑草酮在空气、水和土壤中的挥发率均小于1%,属于难挥发农药。氨唑草酮在湖泊(杭州西湖)水-沉积物系统和河流(京杭大运河)水-沉积物系统中的降解符合一级动力学方程,好氧降解半衰期分别为408 d和630 d,厌氧降解半衰期分别为248 d和990 d,在水-沉积物系统中属于难降解农药。