未净化Z：ZCLA长爪沙鼠封闭群繁育及遗传稳定性分析

目的分析未净化Z：ZCLA长爪沙鼠封闭群繁育和生长指标,并利用直接测序法分析其遗传稳定性。方法随机选择40对Z：ZCLA长爪沙鼠,记录其繁殖胎次、产子数等指标,分析其仔鼠的生长发育情况。遗传稳定性分析选择Z：ZCLA长爪沙鼠非同胞、非亲代个体33只,提取肝脏基因组DNA,PCR扩增D-Loop序列,产物纯化后双向测序,测序结果与Z：ZCLA长爪沙鼠标准序列比对。结果 Z：ZCLA长爪沙鼠每胎产仔7只,胎间隔多在20～60 d间,雄性体重高于雌性。遗传稳定性分析检测发现33只Z：ZCLA长爪沙鼠序列与标准序列完全一致。结论 Z：ZCLA长爪沙鼠群体内未发现遗传多态性,说明该群体具有较好的遗传稳定性。     

大兴安岭南部山地苔藓植物区系多样性研究

于2009～2012年对大兴安岭南部山地6个自然保护区的苔藓植物进行了野外实地调查,对所采集的1 800余号标本进行室内分析鉴定,并计算分析其种类组成、区系地理成分、地区之间相似性系数和相异系数的欧氏距离比较,及其8种生境中苔藓植物多样性指数、丰富度指数、均匀度指数和优势度指数等,为保护区的管理和建设提供基础资料。结果表明:(1)大兴安岭南部山地6个自然保护区共有苔藓植物48科,134属,330种,其中苔类16科,21属,38种,1变种;藓类32科,113属,274种,14变种,2变型,1亚种。(2)首次发现中国新记录4种:长柄紫萼藓(Grimmia longirostris Hook.),毛尖连轴藓[Schistidium lancifolium(Kindb.)Blom.],平叶真藓(Bryumlaevifilum Syed.),凹叶毛灰藓[Homomallium adnatum(Hedw.)Broth.],首次发现本地区新记录12种。(3)以丛藓科为代表的旱生藓类在本区占有优势地位;区系地理成分以温带成分(60.79%)和东亚成分(16.19%)为主。(4)大兴安岭南部山地与兴安北部和燕山北部山地亲缘关系较近;生境条件的变化对苔藓植物多样性产生了一定的影响,湿润土生和石生生境为本区苔藓植物最丰富的生境,水生生境中苔藓植物分布最少。研究发现,大兴安岭南部山地苔藓植物区系是连接华北区、东北区、蒙新区和阴山地区的过渡性地带;与燕山北部和兴安北部相比,大兴安岭南部山地大面积苔藓植物地被层分布较少的主要原因是森林密度和湿度较低。因此,建立保护区对保护大兴安岭南部山地脆弱的森林、草原过渡生态系统,保护中国野生动植物类群及其他珍稀动植物的繁衍均具有十分重要的意义。     

四种独立通风笼具（IVC）的检测

目的比较4种独立通风笼具（individually ventilated cages,IVC）的环境参数。方法参考GB14925-2001的检测方法对分别来自4个厂家生产的4种不同的IVC进行环境检测。结果4种IVC在空气洁净度、落下菌、噪声和照度等4个指标检测数据较为一致;在梯度压差、换气次数、气流速度等3个指标存在较大的差别;而温湿度等指标取决于IVC所处的外部环境。结论目前缺乏国家标准对IVC环境指标进行限定,各厂家所生产的IVC存在差异,需要在此方面加强研究,以促进IVC的标准化,更好的服务于实验动物行业。     

Adaptive phenotypic plasticity of Pseudoroegneria spicata: response of stomatal density, leaf area and biomass to changes in water supply and increased temperature

Background and Aims

Changes in rainfall and temperature brought about through climate change may affect plant species distribution and community composition of grasslands. The primary objective of this study was to test how manipulation of water and temperature would influence the plasticity of stomatal density and leaf area of bluebunch wheatgrass, Pseudoroegneria spicata. It was hypothesized that: (1) an increased water supply will increase biomass and leaf area and decrease stomatal density, while a reduced water supply will cause the opposite effect; (2) an increase in temperature will reduce biomass and leaf area and increase stomatal density; and (3) the combinations of water and temperature treatments can be aligned along a stress gradient and that stomatal density will be highest at high stress.

Methods

The three water supply treatments were (1) ambient, (2) increased approx. 30 % more than ambient through weekly watering and (3) decreased approx. 30 % less than ambient by rain shades. The two temperature treatments were (1) ambient and (2) increased approx. 1–3 °C by using open-top chambers. At the end of the second experimental growing season, above-ground biomass was harvested, oven-dried and weighed, tillers from bluebunch wheatgrass plants sampled, and the abaxial stomatal density and leaf area of tillers were measured.

Key Results

The first hypothesis was partially supported – reducing water supply increased stomatal density, but increasing water supply reduced leaf area. The second hypothesis was rejected. Finally, the third hypothesis could not be fully supported – rather than a linear response there appears to be a parabolic stomatal density response to stress.

Conclusions

Overall, the abaxial stomatal density and leaf area of bluebunch wheatgrass were plastic in their response to water and temperature manipulations. Although bluebunch wheatgrass has the potential to adapt to changing climate, the grass is limited in its ability to respond to a combination of reduced water and increased temperature.Key words: Bluebunch wheatgrass, Pseudoroegneria spicata, biomass, climate change, grassland, open top chamber, rain shade, stomata     

Using microwave irradiation in Marchi's method for demonstrating degenerated myelin

Conventional methods for histological preparation of degenerated myelin are time-consuming and difficult. The purpose of our study was to shorten the time required for the procedure and to obtain better quality results for light microscopic demonstration of degenerated myelin in the central and peripheral nervous systems by using microwave irradiation. Rat brain and sciatic nerve were used for the study. The middle cerebral artery was occluded and the sciatic nerve was cut to produce myelin degeneration. Marchi's method was used for staining degenerated myelin. Fixation for light microscopy that would take two days using the conventional procedure was completed in 16.5-18.5 min using microwave irradiation. While staining of degenerated myelin requires 10 days for the conventional Marchi method, we decreased it to 7 h for brain tissue and 1 h for sciatic nerve by using the microwave oven. Moreover, a better quality preparation was achieved in the groups stained under microwave irradiation than those prepared by the conventional method.     

豆科黄结属模式及其相关种名的考证

长期以来,Ｔermopsis lanceolata R.Br.被误认为是黄华属的模式。根据有关文献考证和国际植物命名法规,作者为认Ｔ.;lanceoltata是一个不合法名,黄华属的合法模式应为Ｔhermopsis Lupinoides(L.)Link.分布于东北亚,花具互生花的黄华长期被误定为Ｔ。lupinoides(L.)Link,应更正为Ｔhermopsis fabacea(Pall)DC.。