四川乌头和附子气候生态适宜性研究

本文在分析乌头和附子的生态要求及其主要分布产区的气候环境的基础上,根据模糊集合论(Fuzzy sets)分别建立乌头和附子5个生态气候要素的隶属函数模型,以50个市(县)气象台(站)为代表,综合评价了四川省乌头和附子产地气候条件的生态适宜性;根据综合评判结果,分别将四川划分为3个乌头不同适宜区和4个附子不同适宜区。     

有机氯农药在海河干流水体和菹草中的浓度分布

于2008年3月29日—5月25日对海河干流水体和菹草中的有机氯农药(OCPs)——六六六(HCHs)和滴滴涕(DDTs)的分布进行了采样调查. 结果表明,水体中ρ(HCHs)和ρ(DDTs)分别为3.95～20.15和6.88～35.23 ng/L,平均值为11.11和15.34 ng/L;菹草中w(HCHs)和w(DDTs)分别为2.17～7.82和1.40～22.80 ng/g,平均值分别为4.49和7.79 ng/g,菹草生长旺盛期的w(HCHs)和w(DDTs)最高,其变化主要受水体中ρ(HCHs)和ρ(DDTs)的影响;菹草生长旺盛期HCHs和DDTs的PCF值最高;菹草中HCHs的主要成分为γ-HCH,而水体中为β-HCH;DDT是水体和菹草中DDTs的主要成分,但菹草中DDT的相对含量明显低于水体,与水体相比,DDT在菹草中能进一步被降解,且以好氧降解为主.      

Abnormal Cranial Variation in the Sable (Martes zibellinaL.) and the State of Environment

An abnormal cranial variation in the sable (Martes zibellinaL.) from the extreme Russian Northeast was studied. In the populations formed as a result of reacclimation, the proportion of animals with morphological cranial anomalies proved to be significantly higher than in the parental populations (from which the animals for reintroduction were taken). Probable factors responsible for this effect are discussed.     

Phenes of Woody Plants: Identification,Scaling, and Use in Population Studies (An Example of Pinus sylvestrisL.)

The methods of identification and scaling of phenes of forest plants are described. The phene identification consists of five stages. Specific features of studies at each stage are shown using identification of the phenes of seed color, cone color, and seed scale structure in Scotch pine (Pinus sylvestrisL.) as examples. The method of phene scaling is based on the comparison of phene frequencies in a bog and in adjacent upland populations of pine. At the boundary between the bog and dry land, the frequencies of population-level phenes change, whereas those of superpopulation-level phenes remain unchanged.     

Bridging the gap between ecophysiological and genetic knowledge to assess the adaptive potential of European beech

In this study we aimed to combine knowledge of the ecophysiology and genetics of European beech to assess the potential of this species to adapt to environmental change. Therefore, we performed field and experimental studies on the genetic and ecophysiological functioning of beech. This information was integrated through a coupled genetic–ecophysiological model for individual trees that was parameterized with information derived from our own studies or from the literature. Using the model, we evaluated the adaptive response of beech stands in two ways: firstly, through sensitivity analyses (of initial genetic diversity, pollen dispersal distance, heritability of selected phenotypic traits, and forest management, representing disturbances) and secondly, through the evaluation of the responses of phenotypic traits and their genetic diversity to four management regimes applied to 10 study plots distributed over Western Europe. The model results indicate that the interval between recruitment events strongly affects the rate of adaptive response, because selection is most severe during the early stages of forest development. Forest management regimes largely determine recruitment intervals and thereby the potential for adaptive responses. Forest management regimes also determine the number of mother trees that contribute to the next generation and thereby the genetic variation that is maintained. Consequently, undisturbed forests maintain the largest amount of genetic variation, as recruitment intervals approach the longevity of trees and many mother trees contribute to the next generation. However, undisturbed forests have the slowest adaptive response, for the same reasons.Gene flow through pollen dispersal may compensate for the loss in genetic diversity brought about by selection. The sensitivity analysis showed that the total genetic diversity of a 2 ha stand is not affected by gene flow if the pollen distance distribution is varied from highly left-skewed to almost flat. However, a stand with a prevailing short-distance gene flow has a more pronounced spatial genetic structure than stands with equal short- and long-distance gene flows. The build-up of a spatial genetic structure is also strongly determined by the recruitment interval. Overall, the modelling results indicate that European beech has high adaptive potential to environmental change if recruitment intervals are short and many mother trees contribute to the next generation.The findings have two implications for modelling studies on the impacts of climate change on forests. Firstly: it cannot be taken for granted that parameter values remain constant over a time horizon of even a few generations – this is particularly important for threshold values subject to strong selection, like budburst, frost hardiness, drought tolerance, as used in species area models. Secondly: forest management should be taken into account in future assessments, as management affects the rate of adaptive response and thereby the response on trees and forests to environmental change, and because few forests are unmanaged. We conclude that a coupled ecophysiological and quantitative genetic tree model is a useful tool for such studies.     

干扰烟草GA 20-氧化酶siRNA植物表达载体的构建及矮化烟草的产生

根据烟草(Nicotiana tabacum)GA 20-氧化酶基因序列,设计2对分别含有特定酶切位点的特异引物,以烟草基因组DNA为模板,扩增目的基因(约250 bp)片段.将正、反向目的片段分别插入中间载体的内含子两侧.再经BamH I和Sac I双酶切回收约700 bp的目的片段,插入到双元载体质粒p2355中,成功构建了含GA 20-氧化酶基因片段的反向重复序列植物表达载体p23700,其转录产物能形成发夹RNA(hpRNA),产生小分子干扰RNA,干扰目的基因的表达.将p23700质粒导入根癌农杆菌EHA105中并转化烟草叶片细胞,经选择分化培养,获得表型矮化的转基因烟草.图4参14     

新发展阶段我国企业水信息披露评价研究

推动绿色发展,促进人与自然和谐共生是我国社会主义建设新时期的重点方向与方略。绿水青山就是金山银山,水信息披露作为治理企业水污染的首要环节、重要手段,在国内还未充分引起企业与有关部门的重视。本文通过构建中国上市公司水信息披露指标体系,弥补了我国多年来在水信息披露评价体系中的不足。基于该指标体系,结合三维度打分法、层次分析法和内容分析法,本研究人工搜集整理既往企业水信息并从披露整体情况、披露水平以及披露内容三个方面分析了我国上市企业水信息披露现状。结果表明,现阶段我国企业水信息披露还存在披露程度低、披露差异明显、披露内容可靠性不强等问题,其根源来自政府政策滞后、社会面监督不充分、企业战略缺失等因素。为此,本文从健全水信息披露框架、完善法律制度、落实法律监督、建立新闻发布制度、引导金融机构参与等方面为推动企业水信息披露提供建议。     

商陆和烟草对锰胁迫的抗氧化响应研究

研究植物的重金属累积能力对于植物修复和植物冶金意义重大.Mn超累积植物商陆(Phytolacca americana L.)的耐性/累积机制至今还不清楚,为了研究商陆在Mn胁迫下的抗氧化酶作用,将萌发6周的商陆和烟草幼苗分别放入1 mmol·L~(-1)或3 mmol·L~(-1)的1/2 Hoagland营养液处理4 d,实验表明商陆叶片光合速率降低幅度显著低于烟草,而烟草MDA含量和电解质渗漏量增加幅度大于商陆.如1 mmol·L~(-1) Mn处理4 d后,与对照相比,商陆和烟草的光合速率分别降低13.3%和75.5%;烟草MDA含量和电解质渗漏量分别增加347.3%和120.1%,而商陆的MDA含量和电解质渗漏量没有明显增加,表明Mn胁迫对超累积植物引起的氧化损伤明显低于非累积植物.随着Mn处理浓度的提高和时间的延长,2种植物叶片SOD和POD活性均迅速增加,其中商陆SOD活性的增加幅度大于烟草;另外,商陆CAT活性持续上升,而烟草CAT活性显著下降.如在1 mmol·L~(-1) Mn处理下,商陆SOD、POD和CAT活性分别提高161.1%、 111.3%和17.5%;烟草SOD和POD提高55.5%和206.0%,而CAT下降15.6%,表明商陆的抗氧化酶,特别是CAT,能够有效地清除Mn毒产生的自由基.这些结果说明抗氧化酶的抗氧化能力是重金属累积植物商陆的Mn耐性机制之一.     

基于多孔环形喷嘴的可燃爆粉尘分散特征的密度效应研究*

为了研究不同密度的可燃爆粉尘在内置多孔环形喷嘴的20 L爆炸特性测试装置中的分散特征,基于负载粒子流方法、耦合DPM动量平衡方程和时间平均 Navier Stokes控制方程组,实现3种不同密度的煤粉、铝粉和锆粉在20 L爆炸测试装置中粉尘分散全过程的数值模拟。研究结果表明:多孔环形喷嘴的分散较为均匀,但是约束管道末端存在局部粉尘残留区,致使爆炸仓内真实粉尘浓度远低于形式浓度;爆炸仓中心位置的最大湍动能随着粉尘密度的增加而减小,只有显著地变化粉尘密度才能展示区分度较高的浓度峰值和抵达浓度峰值的时间。     

小飞扬草(Euphorbia thymifolia L.)中镉的亚细胞分布及化学形态

采用差速离心法和逐步提取法,分析Cd超积累植物小飞扬草根、茎、叶中Cd的亚细胞分布和化学形态.培养液中Cd浓度5mg/L和10 mg/L条件下,在小飞扬草根、茎、叶中,细胞壁和细胞膜是Cd主要的结合场所,含量分别占总量的47.1％～49.0％、39.7％～41.4％、42.9％～56.2％,其次是胞液组分,含量分别占37.5％～41.4％、28.2％～40.7％、35.2％～46.8％,细胞器组分中Cd含量较少.Cd在小飞扬草根、茎、叶中均以氯化钠提取态为主,含量分别占70.5％～84.8％、72.4％～83.0％、50.0％～74.8％.根部各提取态含量依次为CNaCl＞CHAC＞CEtOH＞CHCl＞CW＞CR,茎、叶中各提取态含量依次为CNaCl＞CHCI＞CHAC＞CEtOH＞CW＞CR.在小飞扬草中,Cd与细胞壁和细胞膜中的果胶酸和蛋白质等物质结合固定,而进入细胞的Cd大部分与有机酸络合而隔离于液泡内,这可能是小飞扬草忍耐并超积累Cd的机制.