Soil water characteristics in mountain poplar stand and its benefits to soil and water conservation in loess hilly region

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丛枝菌对转Bt基因棉根际土壤营养物质及酶活性的影响

转Bt基因抗虫棉已在全球范围内广泛种植,然而Bt棉根际分泌物是否会影响土壤理化性质及土壤功能尚缺乏深入研究。通过盆栽实验方法,设计不同的棉花品种与是否接种丛枝菌总共4个处理,以此研究Bt棉和接种丛枝菌根真菌对植物根际土壤营养物质含量以及土壤酶活性的影响。结果显示:丛枝菌可以使non-Bt棉和Bt棉根际土壤营养物质中的土壤有机质和土壤总氮含量显著增加,但是对根际土壤全磷却鲜有影响。转基因对于不同品种棉花根际土壤酶,丛枝菌均能有效增强其活性。由此表明,丛枝菌对Bt棉和non-Br棉根际土壤环境均具有改善作用。     

中型景观尺度下斑块类型和地理特征影响杨树人工林干部病害的发生——以河南省清丰县为例

景观病理学在开展病原扩散、病害发生及其严重程度方面以其全新的视角,为森林病害的区域控制提供了新的研究技术及理论支持。首次利用景观病理学原理和方法对河南省清丰县一个中型景观下杨树人工林干部病害发生特征开展了研究,目的是解析在大尺度下斑块类型和地理特征对杨树人工林病害发生的影响。在100 km2的调查区域,以种植方式和林分类型划分斑块类型,分析显示发病株率在不同斑块间差异显著：农田间作斑块的林木发病株率显著低于孤立斑块、纯林斑块、混交林等斑块的发病株率;但发病株率在孤立斑块、纯林斑块及混交林等斑块间无显著差异。抚育管理措施对预防和减轻杨树人工林干部病害的发生起到关键左右：精细管理林分（有修枝、施肥和锄草）的林木发病株率（p=0.001）和发病指数（p〈0.001）均显著低于粗放管理林分（无修枝、无施肥和锄草等）。人类活动,如无序修剪和放牧很可能是造成村落附近林分发病率显著高于其他地点林分的主要原因。采用logistic回归,以品种编号、树龄、树高、林分密度、林分郁闭度、林分类型、斑块类型、地理特征,等为自变量建立病害发生预测模型。方程拟合达到极显著水平（Wald=71.248,p〈0.001）。方程总的预测正确率为68.2%,发病的预测正确率为79.8%。     

祁连山北坡自然恢复杨桦林地植物功能型组成及其影响因素

依据生活型(乔木、藤本、灌木、半灌木、多年生禾草、多年生杂类草和一二年生草本)和水分生态型(旱生、旱中生、中生和湿生)将祁连山北坡次生杨桦林28个调查样地中的81个物种划分为18种植物功能型(Plant functiontypes,PFTs),并通过典范对应分析(CCA)方法研究植物功能型与环境因子间的关系.结果表明:自然恢复杨桦林地植物功能型主要集中在中生多年生杂类草(PFTs16)、湿生多年生杂类草(PFTs23)、旱中生多年生杂类草(PFTs9)和中生灌木(PFTs18)4个植物功能型上;乔、灌、草三层冠层特征和中生植物的大量出现,反映了群落植物生活型趋于复杂化和结构化,生态型逐渐向中生化方向演替的特点;土壤容重、有机碳和全氮含量主要影响植物的生活型分异特征,土壤含水量和林冠郁闭度是植物的水分生态型分异的主要环境因子,而坡位、坡度控制着群落植物总体分布格局的形成.图1表3参31     

Science and the Consequences of Mistruct: Lessons from Recent GM Controversies

In 2001, it was announced thattransgenic DNA had introgressed intotraditional strains of maize in Mexico. Acontroversy erupted and raged throughout 2001and 2002. This episode represents an acutebreakdown in scientific discourse. Given thestakes in the genetically modified organismdebate, a breakdown in scientific discourse isalarming. The following inquiry looks into thecauses of this breakdown. Ultimately, it willbe argued that the underlying problem is thecurrent institutional structure of science,particularly in the United States. If thediagnosis is correct, then the proper course oftreatment is to pursue a program ofinstitutional reconstruction.     

A Quantitative Safety Assessment Model For Transgenic Protein Products Produced In Agricultural Crops

Transgenic plants are now being used to develop pharmaceutical and industrial products in addition to their use in crop improvement. Using confinement requirements, these transgenic plants are grown and processed under conditions that prevent intermixing with commodity crops. Regulatory agencies in the United States have provided guidance of zero tolerance of these new industrial crops with commodity crops. While this is a worthy goal, it is theoretically unattainable. In spite of the best containment practices, there is a potential risk using any system of production due to unforeseen incidences including natural disasters or exposure to workers. The precautionary principle has been used for numerous regulated articles in addressing the potential risks of new products and technology based on a risk assessment in similar situations. We present here a risk assessment model that could be used as a start to develop an accepted model for the industry. The model is based on current risk models used for other regulated articles, but adapted for these types of products. This could be used to determine action levels in the event of an unintended exposure or to ensure that detection or confinement methods are adequate to avoid risks. As an example, aprotinin, a therapeutic protein now being produced in maize, was evaluated for potential risk to humans using this model.     

多年连续种植转基因Bt汕优63稻田水体和土壤中Cry1Ab/c蛋白残留调查

以湖北武汉、随州、武穴和孝感以及山东德州5个多年转基因水稻种植区为试验地,在水稻生育期采集转cry1 Ab/c基因水稻Bt汕优63(Bt-SY63)和对照非转基因汕优63(SY63)稻田水体和土壤,使用酶联免疫吸附测定(ELISA)方法对稻田水体和土壤Cry1 Ab/c蛋白残留量进行动态监测.结果显示,与SY63稻田相比,连续种植2～4 a后,不同生育期Bt-SY63稻田水体Cry1Ab/c蛋白残留量大多与同一生育期SY63样品间差异未达显著水平(P＞0.05),最高残留量为0.373 ng· mL-1.与水体Cry1Ab/c蛋白残留情况相似,不同生育期Bt-SY63稻田土壤Cry 1Ab/c蛋白残留量大都低于试剂盒检测限(0.25 ng·g-1),仅随州苗期、德州拔节期和开花期样品有微量残留,鲜土残留量分别为0.261、0.540和0.361 ng·g-1,并分别与SY63样品间差异显著(P＜0.05).另外,多年连续种植Bt-SY63水稻后,2、3和4a种植年限的Bt-SY63稻田水体和土壤中Cry1Ab/c蛋白残留量之间大都没有显著差异(P＞0.05).认为连续种植2、3和4a的Bt-SY63水稻稻田水体和土壤仅存在微量Cry1Ab/c蛋白残留,不会造成Cry1Ab/c蛋白在稻田水体和土壤中的累积.     

An integrative analysis of miRNA and mRNA expression in the brains of Alzheimer's disease transgenic mice after real-world PM2.5 exposure

Fine particulatematter (PM2.5) is associated with increased risks of Alzheimer’s disease (AD),yet the toxicologicalmechanisms of PM2.5 promoting AD remain unclear. In this study,wildtype and APP/PS1 transgenic mice (AD mice) were exposed to either filtered air (FA) or PM2.5 for eight weeks with a real-world exposure system in Taiyuan, China (mean PM2.5 concentration in the cage was 61 μg/m3). We found that PM2.5 exposure could remarkably aggravate AD mice’s ethological and brain ultrastructural damage, along with the elevation of the pro-inflammatory cytokines (IL-6 and TNF-α), Aβ-42 and AChE levels and the decline of ChAT levels in the brains. Based on high-throughput sequencing results, some differentially expressed (DE) mRNAs and DE miRNAs in the brains of AD mice after PM2.5 exposure were screened.Using RT-qPCR, seven DEmiRNAs (mmu-miR-193b-5p, 122b-5p, 466h-3p, 10b-5p, 1895, 384–5p, and 6412) and six genes (Pcdhgb8, Unc13b, Robo3, Prph, Pter, and Tbata) were evidenced the and verified. Two miRNA-target gene pairs (miR-125b-Pcdhgb8 pair and miR-466h-3p-IL-17Rα/TGF-βR2/Aβ-42/AChE pairs) were demonstrated that they were more related to PM2.5-induced brain injury. Results of Gene Ontology (GO) pathways and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways predicted that synaptic and postsynaptic regulation, axon guidance, Wnt, MAPK, and mTOR pathways might be the possible regulatory mechanisms associated with pathological response. These revealed that PM2.5- elevated pro-inflammatory cytokine levels and PM2.5-altered neurotransmitter levels in AD mice could be the important causes of brain damage and proposed the promising miRNA andmRNA biomarkers and potentialmiRNA-mRNA interaction networks of PM2.5-promoted AD.     

转基因生物风险评估和管理的国家能力建设的探讨

转基因生物风险评估和管理的国家能力建设的内容,包括机构、机制、专家知识、环境监测以及信息收集和交流等。风险评估和管理的能力建设必须根据本国生物技术研究和应用水平、资金、信息以及人员数量和素质来确定其优先领域、行动和项目。目前,中国转基因生物风险评估和管理的国家能力建设工作亟待开展的有:成立国家生物安全委员会;建立转基因生物风险评估和管理的制度以及公众参与的机制;提高技术人员和管理者在生态学、遗传学和风险评估方法学等方面的专家技能;制定转基因生物的环境监测规划;建立有关转基因生物的环境监测网络和基地;新建一批生物安全数据库和信息库     

杨树刺槐混交林沙地土壤的水分—物理性质

研究了刺槐与杨树混交林后沙地土壤水分－物理性质变化的状况，结果表明，刺槐与杨树混交后，土壤水分－物理性质得到了改善，表现在土壤最大持水量增加，毛管持水量、田间持水量得以提高，土壤有效持水量也有了较大幅度的提高，刺槐与杨树混交后土壤总孔隙度、非毛管孔隙度、毛管孔隙度得到提高，并由此而改善了混交林土壤的渗透性能，表4参7