7种黔产淫羊藿可杂交性研究

对原产贵州的14个居群、共7个种的淫羊藿属植物进行配对杂交及其结实率统计分析研究。结果显示,该属所有的种类都可以杂交,不同的杂交组合的杂交结实率存在着明显的差异,结实率最低的为15.38%,最高可以达到92.94%;从结实率看,7个种可以明显分成两类:1类,就是E.myrianthum,和另外6个种的结实率均较低,绝大多数在30%以下,2类,包括剩余的6个淫羊藿种,两两之间的杂交结实率较高。研究结果对该属植物进一步的品种培育研究提供了一定参考,同时也为该属植物的系统进化研究提供了一定的资料。     

6个黔产淫羊藿属植物的过氧化物酶同工酶分析

对原产贵州的6个淫羊藿属植物进行了过氧化物酶同工酶比较分析。其结果表明,该属的过氧化物酶同工酶谱共有5条带,各个种之间的同工酶酶谱具有明显的差异。从POD酶谱上分析,E.acum inatum、E.wush-anense、E.chlorandrum、E.baiea li-guizhouense4个种之间的亲缘关系非常近;而E.sagittatum、E.letorrhizum2个种之间的亲缘关系非常远,与另外4个种之间的系统关系也较远。同时,推测认为该属在进化上是非常古老的一个类群。     

杂草繁殖方式的多样性及其对环境的适应

杂草是在人为和环境双重选择压力下演化而成的一类高度进化的植物类群,其繁殖方式多样,表现在种子产量、萌发、休眠、拟态、生命力、繁殖体传播方式等。作者以举例方式比较详细地论述了杂草多样的繁殖方式,并讨论其对人为干扰环境适应的意义。     

宜君县野生动植物和自然保护区建设现状及对策

分析了宜君县野生动植物和自然保护区建设的现状,归纳了存在的问题,提出了今后做好宜君县野生动植物和自然保护区建设工作的对策.     

野生地被植物光叉叶委陵菜的引种栽培

采用观测调查与引种栽培试验相结合的方法,对野生植物光叉叶委陵菜对光的适应性、繁殖方式、耐践踏性能、病虫害情况、保持水土性能、经济价值、景观配置进行了研究,结果表明,光叉叶委陵菜是北方干旱地区不可多得的园林地被植物,应在生产上推广应用.     

野生地被植物光叉叶委陵菜的引种栽培

采用观测调查与引种栽培试验相结合的方法,对野生植物光叉叶委陵菜对光的适应性、繁殖方式、耐践踏性能、病虫害情况、保持水土性能、经济价值、景观配置进行了研究,结果表明,光叉叶委陵菜是北方干旱地区不可多得的园林地被植物,应在生产上推广应用。     

垫状锦鸡儿的繁殖方式及其在适应干旱荒漠环境中的生态意义

研究内蒙古荒漠区锦鸡儿属优势种垫状锦鸡儿灌丛结构、分株特征、繁殖倾向和克隆生长特性.结果表明:在荒漠区,垫状锦鸡儿的营养繁殖占主导地位,有性繁殖为辅;其营养繁殖由枝条克隆产生无性系分株,克隆生长构型为密集型.较高的无性繁殖比例、密集型的克隆构型和发达的根系使垫状锦鸡儿能很好地适应荒漠区的干旱环境,并成为荒漠区的优势种.     

北美车前不同种群密度下的生理指标及其适应意义

测定了相近环境条件下,高密度和低密度种群的北美车前在不同生长时期的叶绿素α／b值、过氧化物酶(POD)活性、可溶性糖及脯氨酸(Pro)的含量。结果表明,各个生长时期的北美车前,高密度种群的叶绿素α／b值低于低密度种群,而POD活性、可溶性糖含量和叶片游离脯氨酸含量都高于低密度种群,并分析了4种生理指标的变化与种群对环境适应间的相关性。     

Upgrading and dephosphorization of Western Australian iron ore using reduction roasting by adding sodium carbonate

The technology of direct reduction by adding sodium carbonate (Na₂CO₃) and magnetic separation was developed to treat Western Australian high phosphorus iron ore. The iron ore and reduced product were investigated by optical microscopy and scanning electron microscopy. It is found that phosphorus exists within limonite in the form of solid solution, which cannot be removed through traditional ways. During reduction roasting, Na₂CO₃ reacts with gangue minerals (SiO₂ and Al₂O₃), forming aluminum silicate-containing phosphorus and damaging the ore structure, which promotes the separation between iron and phosphorus during magnetic separation. Meanwhile, Na₂CO₃ also improves the growth of iron grains, increasing the iron grade and iron recovery. The iron concentrate, assaying 94.12wt% Fe and 0.07wt% P at the iron recovery of 96.83% and the dephosphorization rate of 74.08%, is obtained under the optimum conditions. The final product (metal iron powder) after briquetting can be used as the burden for steelmaking by an electric arc furnace to replace scrap steel.     

贵州几种野生石斛的引种栽培和繁殖技术

近年来 ,在贵州不同地区采集了石斛 (D .nobileLindl)、密花石斛 (D .densifiorumLindl.ex.wall)、美花石斛(D .loddigesiiRolfe)和细叶石斛 (D .hancockiiRolfe)共 4种 ,并进行人工模拟野生环境室内、室外的栽培试验和无土栽培 ,同时探索出较好的栽培技术、繁殖技术和栽培管理措施 ,现已引种成功     

污染环境下具捕获及扩散的单种群持久性与灭绝性

研究了在污染环境中具有捕获及扩散的单种群在两斑块之间扩散后,种群的持久性和灭绝性问题.一个斑块是保护区,另一个斑块是污染区,在两个斑块内都进行捕获.通过对右端函数的分析,得到种群持久和灭绝的充分条件,并指出捕获及扩散对种群的影响.     

化学溶液法制备BiVO4纳米晶及其结构、形貌及光谱性质研究

采用安全、绿色、节能的化学溶液法合成了BiVO_4纳米晶.通过改变反应体系的pH值,来调控纳米晶生长的动力学因素,探索不同结构、形貌和尺寸的纳米晶的形成机制及光谱性质的变化规律.结果表明,在酸性条件,四方相BiVO_4为热稳定相.但在弱碱条件,由于热动力学,反应趋向于形成单斜相BiVO_4.在强碱条件,单斜相BiVO_4的特征衍射峰强度降低.在不同pH值条件下合成的BiVO_4纳米晶的晶粒尺寸均处于纳米量级.在化学合成过程中,体系的pH值对样品形貌的形成起着十分关键的作用.由于Bi~(3+)离子的水解作用,使其可以在不同的pH值条件下以不同的形式存在,导致在合成BiVO_4过程中具有不同的合成路径,进而使得在不同pH值条件下合成的BiVO_4样品具有不同的形貌特征.采用Raman光谱研究了不同BiVO_4纳米晶的局部结构,在326和363cm~(-1)的峰对应于VO_4~(3-)四面体的反对称和对称弯曲振动,在712和828cm~(-1)的峰对应于V-O的对称和反对称拉伸振动.不同BiVO_4纳米晶在紫外和可见光区均有明显吸收,而其吸收边界的急剧下降推断是由于半导体的带间跃迁造成的.不同晶相BiVO_4纳米晶的吸收带边有明显的不同,表明随着晶相的改变,样品内部电子结构发生了变化.在pH=3时合成的BiVO_4纳米晶的发光峰强度最低,表明该复合催化剂的电子空穴复合效率最低,暗示其光催化活性较高.     

Kinetic redistribution of native and misfolded RNAs by a DEAD-box chaperone

DExD/H-box proteins are ubiquitously involved in RNA-mediated processes and use ATP to accelerate conformational changes in RNA. However, their mechanisms of action, and what determines which RNA species are targeted, are not well understood. Here we show that the DExD/H-box protein CYT-19, a general RNA chaperone, mediates ATP-dependent unfolding of both the native conformation and a long-lived misfolded conformation of a group I catalytic RNA with efficiencies that depend on the stabilities of the RNA species but not on specific structural features. CYT-19 then allows the RNA to refold, changing the distribution from equilibrium to kinetic control. Because misfolding is favoured kinetically, conditions that allow unfolding of the native RNA yield large increases in the population of misfolded species. Our results suggest that DExD/H-box proteins act with sufficient breadth and efficiency to allow structured RNAs to populate a wider range of conformations than would be present at equilibrium. Thus, RNAs may face selective pressure to stabilize their active conformations relative to inactive ones to avoid significant redistribution by DExD/H-box proteins. Conversely, RNAs whose functions depend on forming multiple conformations may rely on DExD/H-box proteins to increase the populations of less stable conformations, thereby increasing their overall efficiencies.     

Rejuvenation of aged progenitor cells by exposure to a young systemic environment

The decline of tissue regenerative potential is a hallmark of ageing and may be due to age-related changes in tissue-specific stem cells. A decline in skeletal muscle stem cell (satellite cell) activity due to a loss of Notch signalling results in impaired regeneration of aged muscle. The decline in hepatic progenitor cell proliferation owing to the formation of a complex involving cEBP-alpha and the chromatin remodelling factor brahma (Brm) inhibits the regenerative capacity of aged liver. To examine the influence of systemic factors on aged progenitor cells from these tissues, we established parabiotic pairings (that is, a shared circulatory system) between young and old mice (heterochronic parabioses), exposing old mice to factors present in young serum. Notably, heterochronic parabiosis restored the activation of Notch signalling as well as the proliferation and regenerative capacity of aged satellite cells. The exposure of satellite cells from old mice to young serum enhanced the expression of the Notch ligand (Delta), increased Notch activation, and enhanced proliferation in vitro. Furthermore, heterochronic parabiosis increased aged hepatocyte proliferation and restored the cEBP-alpha complex to levels seen in young animals. These results suggest that the age-related decline of progenitor cell activity can be modulated by systemic factors that change with age.     

3种檵木属植物结构解剖及环境适应性评价

应用叶片离析法和石蜡切片技术,比较了3种(含变种)檵木属植物根茎叶的结构解剖特征。研究结果表明:檵木及其变种红花檵木的根茎叶结构表现出具有较强的耐旱或耐寒性特征,其叶上表皮具表皮毛,角质层较厚,栅栏组织发达,细胞排列紧凑,叶片紧实度大; 茎部和根部韧皮部、木质部发达; 而四药门花则表现出喜阴环境的特点,其叶上表皮无表皮毛,角质层较薄,叶片紧实度小(17.89%),栅栏组织和海绵组织比值小,细胞排列疏松,叶片疏松度大(48.93%),茎部具有发达的髓腔和较发达的木质部。隶属函数值分析结果显示,檵木属3个树种对环境适应性从强到弱依次为红花檵木>檵木>四药门花。     

3种蕨类植物对锰污染土壤的耐受性及生理响应

为筛选锰富集能力强的蕨类植物并分析其生理机理,以粉背蕨、蜈蚣草、井栏边草为材料,研究了不同浓度的锰胁迫对3种蕨类植物的生长、植物体内锰含量以及相关生理指标的影响.结果表明:3种蕨类植物的生长量、生物量随着锰胁迫浓度的提高总体呈现下降的趋势,降幅最大的是井栏边草,蜈蚣草次之,粉背蕨最低,其平均耐性指数分别为79.10%、85.35%、91.12%;3种蕨类植物的锰含量、转运系数(TF)、富集系数(BCF)随锰处理浓度的增加总体呈现先上升后下降的趋势,粉背蕨各指标最高值分别为6 598.31mg/kg,0.89和0.69,均高于其他两种植物,蜈蚣草次之,而井栏边草最低;随着锰胁迫浓度的增加,3种蕨类植物叶绿素含量总体呈现下降的趋势,丙二醛(MDA)含量持续上升,而超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性表现为先升后降的趋势.粉背蕨的叶绿素含量下降幅度和MDA上升幅度均最小,而3种抗氧化酶的增幅却最大.由此可见,高浓度锰处理下蕨类植物生长受抑可能是因为植物体的光合作用受损和氧化损伤,氧化酶活性的提高应是植物能耐锰和富集锰的重要生理原因之一;3种蕨类植物适合修复不同浓度的锰污染土壤,与其他两种植物相比,粉背蕨具有更强的锰耐受性和富集能力.