花生种子特异启动子AHSSP1的克隆及功能分析

为丰富花生种子特异启动子资源,本研究利用PCR技术在花生基因组中克隆了种子贮藏蛋白基因PSC32的启动子AHSSP1,利用半定量RT-PCR检测了PSC32基因表达模式,借助NewPLACE在线分析了AHSSP1序列中存在的顺式作用元件,并构建了AHSSP1驱动GUS报告基因的表达载体,经农杆菌转化获得转基因拟南芥,经GUS组织化学染色鉴定了该启动子的功能。结果表明,PSC32基因957 bp长的启动子AHSSP1序列具备种子特异表达启动子特有的3个RY REPEAT元件。半定量RT-PCR分析发现,PSC32基因在花生成熟种子中表达,而在饱果成熟期根、茎、叶片、花、入土前的果针、成熟种子的果壳中均不表达。GUS组织化学染色发现,转基因拟南芥成熟种子以及萌发种子的子叶、下胚轴和胚根均能够被染上蓝色;长出真叶后,子叶和下胚轴仍能被染色,而根和真叶不能被染上蓝色;成年期转基因拟南芥的叶片也不能被染上蓝色。而野生型拟南芥整个生长时期均不能被染上蓝色。以上现象说明AHSSP1是一个种子特异启动子。本研究丰富了花生种子特异启动子的资源,对花生籽仁品质改良或以花生籽仁作为“生物反应器”的研究具有重要的应用价值。     

国内土壤环境污染防治进程及展望

综述以中国2005—2019年土壤污染防治进程的3个阶段为主线,总结土壤污染防治发展过程中管理模式、治理体系、管控要求、机构改革、立法支持等5个方面重要转变,分析国家和地方土壤环境保护标准、法律法规政策和主要土壤污染治理成效。针对国内土壤污染防治未来发展趋势,从完善土壤环境标准及管理制度、建设监测及预警大数据平台、加强土壤生态环境国际合作、持续推进土壤修复技术攻关和先行区经验推广等方面提出建议,以期为生态环境高水平保护和经济社会高质量发展提供参考。     

In Vitro Evaluation of the Effects of Selected Plants on the Growth of the Mycelial Form of Histoplasma capsulatum Variety farciminosum in Ethiopia

Epizootic lymphangitis is prevalent in equines in Ethiopia, causing remarkable economic and welfare impacts but often neglected. Lack of effective treatment contributed to its continued occurrence, and hence, search for an effective treatment should be considered a priority area to minimize its impacts. Previous ethnobotanical studies have reported that Curcuma longa, Phytolacca dodecandra, and Datura stramonium were used to treat cutaneous fungal infections and reduce their incidence. The treatment effects of these plants against epizootic lymphangitis should be studied. The in vitro growth inhibitory effects of methanol extracts of the root of C. longa, berry of P. dodecandra, and leaf of D. stramonium were evaluated. Histoplasma capsulatum var farciminosum was isolated from clinical cases of epizootic lymphangitis in carthorses in central Ethiopia. The nested polymerase chain reaction was used to confirm the identity of the isolates. Serial twofold dilutions of the extract of berries of P. dodecandra and leaves of D. stramonium were done in sterile water, whereas dilution of the extract of roots of C. longa was done in dimethylsulphoxide. The effects of the plants on the growth of Histoplasma capsulatum var farciminosum were assessed by agar dilution assay. Culture media with no antifungal agent and media containing ketoconazole served as negative and positive control, respectively. The methanol extract of C. longa showed inhibitory effects at concentrations ranging from 0.07 to 5 mg/mL. Similarly, the methanol extract of P. dodecandra showed growth inhibitory effects at concentrations ranging from 0.156 to 5 mg/mL. That is, the growth inhibitory concentration of C. longa was 0.07 mg/mL, whereas that of P. dodecandra was 0.156 mg/mL. In contrast, D. stramonium showed no inhibitory effect. This preliminary observation showed that methanol extracts of C. longa and P. dodecandra showed inhibitory effects on the growth of Histoplasma capsulatum var farciminosum requiring further repeated in vitro evaluation so as to generate adequate evidence, which would justify in vivo trials.     

六堡茶茶褐素体外降脂功效研究

考察六堡茶茶褐素体外结合胆酸盐能力、抑制胰脂肪酶活性及胆固醇酯酶活性能力、吸附胆固醇及油脂能力,从而评价其体外降脂活性。研究结果显示,六堡茶茶褐素对花生油的吸附量为0.73 g·g^-1,对胆固醇的吸附量在酸性条件下为122.42 mg·g^-1、中性条件下为13.68 mg·g^-1;在茶褐素结合胆酸盐的试验中,随着茶褐素浓度的增加,与胆酸盐结合能力也呈上升趋势;茶褐素对胰脂肪酶起激活作用,且随着浓度的增加呈持续上升趋势;对胆固醇酯酶活性抑制IC₅₀值为57.2 mg·mL^-1。六堡茶茶褐素降脂机制可能主要通过与胆酸盐结合、吸附胆固醇和脂肪来实现。     

湿法机械处理改善粘胶级竹溶解浆反应性能的研究

为提高溶解浆进行粘胶纤维产品生产的加工性能及减少二硫化碳的排放，采用PFI（papirindustriens forsknings institut）磨打浆和瓦利打浆机打浆这2种湿法机械处理，以改善竹溶解浆的反应性能。以预水解硫酸盐法竹溶解浆为原料，考察PFI磨打浆及瓦利打浆机打浆对溶解浆反应性能及纤维形态的影响，并对同等打浆度条件下的2种湿法机械处理的效果进行比较。PFI磨和瓦利打浆机分别在打浆度为60.5°SR（15 000 r）及36.4°SR（30 min）的优化工艺条件下，Fock反应性能从68.3%分别提高到73.2%和84.0%，粘胶过滤性能由“不通过”到粘胶过滤值分别为3 196.1 s和2 115.6 s。同时，上述2种处理方式均使纤维粗度和长度下降，细小纤维含量、比表面积和总孔隙量增加，且使聚合度损失小。同等打浆度条件下，基于瓦利打浆机对纤维更多的剪切行为，瓦利打浆机打浆对反应性能的提高效果更为显著。     

Optimizing aphid biocontrol with the predator Aphidoletes aphidimyza,based on biology and ecology

Aphidoletes aphidimyza is one of the most important predators used in the augmentative biological control of aphids, key pests of many crops worldwide. Adult females are very efficient in locating aphid infestations over a relatively long range, up to 45 m, and deposit eggs near or within aphid colonies. The predatory larvae are aphid generalists preying on several agriculturally important aphid species. The successful use of this biocontrol agent in agricultural systems depends on several biotic and abiotic factors. Among biotic factors, aphid species, plant structure, interspecific competition and intraguild predation may significantly impact the predator´s population dynamics. Key abiotic conditions include day lengths (above a critical threshold to prevent diapause), availability of mating sites in the crop, temperature (above 15 °C to enable egg laying), air relative humidity (above 70%) and availability of pupation sites. Although several successes have been reported in open field crops with naturally occurring or released populations, commercial releases are primarily used in protected crops. Optimized emergence boxes combining provisioning of food sources for the adults, integration with the technological advances that occurred in the greenhouse environment lately, insights into the nutritional ecology in open field crops and exploration of the genetic variability are proposed as future directions to improve adoption and efficacy of A. aphidimyza in crop protection. © 2018 Society of Chemical Industry     

Screening oat germplasm for better adaptation to cold stress in the Southern Great Plains of the United States

Oat (Avena sativa L.) is one of the most important forage crops in the Southern Great Plains of the United States. However, it is more sensitive to cold stress than other small grains. In this study, diverse oat germplasm was evaluated for winter survival across multiple years and locations in the region. Field screening started with an observation trial of 1,861 diverse genotypes in the 2012–2013 season and was followed by four seasons of replicated trials from 2013 to 2017. Selection of good winter survivors was started in 2014–2015 season. All trials were laid out in randomized complete blocks with replications of two in 2013–2014 and 2014–2015, four in 2015–2016, and three in 2016–2017. Winter survival was scored in a 1‐to‐9 scale. Data were analysed for each year and location separately. Additive main effects and multiplicative interaction (AMMI) analysis were carried out on combined data of 35 genotypes that were commonly grown in each year and location. Highly significant (p < 0.001) variations were observed among genotypes, environments and genotype‐by‐environment interaction (GEI). The first three interaction principal components (IPCs) were highly significant (p < 0.001), explaining 96% of GEI. Broad sense heritability ranged from 46% to 93%, while heritability for all environments combined was relatively low (24.6%). At the end of the two cycles (2014/2015‐to‐2016/2017) of selection, mean winter survival was improved by more than 38% per cycle compared with the base population mean. Genotypes CIav 4390, CIav 6909 and CIav 7618 showed significantly higher winter survival than the standard checks Okay and Dallas. Genotypes CIav 4390 showed 20% and 35% improvement over the standard checks Okay and Dallas, respectively. Winter survival improvement in oat will remain a difficult task because of high GEI and low heritability. The identified superior genotypes will be used as crossing parents to transfer cold tolerance genes to other elite lines.     

重组白细胞介素-2高效纯化方法建立

依次通过离子交换法、凝胶过滤法纯化重组白细胞介素-2(IL-2)粗品,利用SDS-PAGE电泳和hIL-2 Elisa kit检测纯化后重组IL-2的纯度和浓度。结果表明,纯化后的重组IL-2纯度和浓度高。本纯化方法简单、稳定、纯化效果好,可为重组IL-2的生产工艺提供技术支持和依据。