Spatial pattern of soil carbon and nutrient storage at the alpine tundra ecosystem of Changbai Mountain,China

气候变化对土壤碳和养分的影响越来越受到生态学家的关注,尤其是对高山冻原生态系统的影响。本研究目的是长白山高山冻原系统土壤碳和养分的空间异质性。结果表明:不同土层深度的土壤碳在Meadow alpine tundra vegetation (MA)中显著地高于其他植被类型(p<0.05);在每一植被类型中,表层(010 cm)碳含量显著地高于1020 cm的土层;土壤氮的分布格局是氮素在表层和1020 cm土层变化规律相似;不同土层深度的土壤磷在Lithic alpine tundra vegetation (LA) 中显著地低于其他植被类型(p<0.05);土壤钾浓度在Felsenmeer alpine tundra vegetation (FA) 和LA中显著地高于其他植被类型,但在每一植被类型中土壤钾浓度随土壤深度没有明显的变化;不同深度土壤硫在MA中显著地高度其他植被类型;对每一植被类型而言,C: N, C: P, C: K 和C: S随土壤深度增加而降低。除了在SA的表层外,表层的土壤C: N高于1020 cm的土层。在长白山高山冻原系统中,随植被类型的变化,土壤碳和养分储量有着显著的空间异质性。参29表3图1。     

The biochemical control of the cell cycle by growth regulators in higher plants

The cell cycle is an important research field in cell biology and it is genetically and developmentally regulated in animals and plants. The aim of this study was to review knowledge about the biochemical regulation of the cell cycle by plant growth regulators through molecular checkpoints that regulate the transition from G0-G1-S-phase and G2-M in higher plants.Recent research has shown that zeatin treatment led to the up-regulation of CycD3 in Arabidopsis. Benzyladenine treatment can also shorten the duration of S-phase through recruitment of latent origins of DNA replication. Kinetin is involved in the phosphoregulation of the G2-M checkpoint; the major cyclin-dependent kinase (Cdk) at this checkpoint has recently shown to be dephosphorylated as a result of cytokinin treatment, an effect that can also be mimicked by the fission yeast Cdc25 phosphatase. Gibberellic acid (GA) treatment induces internode elongation in deepwater rice, this response is mediated by a GA-induced up-regulation of a cyclin-Cdk at the G2-M checkpoint. Recent evidence has also linked abscisic acid to a cyclin-dependent kinase inhibitor. A new D-type cyclin, recently discovered in Arabidopsis may have a key role in this process. A brief review on plant growth regulator-cell cycle interfacing during development and a cytokinin-induced continuum of cell cycle activation through the up-regulation of a plant D-type cyclin at the G1 checkpoint and the phosphoregulation of the Cdk at the G2/M checkpoint had been concluded. This review could be valuable to research on cell and developmental biology in plants.     

真菌致泡桐材组分变化研究

用FTIR、ESCA等波谱分析方法，对真菌侵蚀的泡桐材进行了分析，结果表明：真菌侵蚀后，泡桐材的木质素含量相对比例增加、半纤维素含量降低、纤维素含量变化不明显。     

板栗新品系幼树发枝结果习性观测及修剪试验

经对24个板栗新品系幼树的发枝结果习性进行观测,结果表明,新品系平均结果枝占当年萌发枝的50%以上,且连续结果性能好,达到国家板栗丰产选种标准.对24个板栗新品系幼树1年生健壮枝作轻剪、中剪、重剪和不剪(缓放)4种修剪方法的试验,结果表明,轻剪能显著促进幼树发枝和座果,中剪和缓放次之,重剪结实差,发枝少而壮.     

工能基因组学:T-DNA介导的基因诱捕和植物基因鉴定(英文)

拟南芥菜、水稻、蕃茄、土豆、玉米、小麦和大豆的全基因组测序为植物细胞和发育生 物学研究提供了许多有用的信息。基因组学的中心任务是利用这些信息去探索蛋白质的功能 和鉴定与发育有关的重要基因。尽管依赖于毁坏基因和产生可识别的突变表型的经典遗传学 方法仍然是极为成功的基因鉴定方法，借助于报告基因结构，随机插入植物基因组的T-DNA 介导的基因诱捕正发展成为植物细胞和发育生物学研究的极强有力的技术。本文描述了基因 诱捕、启动子诱捕和增强子诱捕在植物生物学中的应用，并且希望这些基因鉴定方法有助于 植物分子生物学家和生物技术工作者的研究。     

赤腹松鼠及其危害防治的研究

赤腹松鼠(Callosciurus erythraeus)是一种以植食为主的树栖啮齿动物，广泛分布于亚洲东南部。随着国内人工造林面积的大幅度增加，生态环境的不断改变，赤腹松鼠对人工林的危害日益严重，已成为森林鼠害的主要害鼠之一。本文从生物学、危害、防治3个方面综述了国内外自20世纪80年代以来有关赤腹松鼠研究进展和防治状况。     

毛白杨无性系木材基本密度遗传变异研究(英文)

对河北、河南、山东、甘肃的４块毛白杨无性系测定林中约１００个无性系进行了木材基本密度的测定，对木材基本密度在地点和无性系间的遗传变异进行了研究．结果表明：毛白杨无性系的木材基本密度平均值为０．４３６３ｇ／ｃｍ３，木材基本密度在地点和无性系间均存在极显著差异．木材基本密度的无性系重复力为０．８２～０．９１，属于受遗传控制较强的材性性状．对生长和材性的相关研究表明，木材基本密度与生长性状（包括胸径、树高和材积）一般存在显著的负相关，但不同地点上表现为不同的正或负的相关关系     

运用航空描图技术对森林病虫害进行监测

本文介绍了航空描图技术在监测森林病虫害上的应用，具体阐明了飞行作业计划、飞行前准备、空中描图技术以及ＧＩＳ数据处理     

Cellular mechanisms underlying Hyperin-induced relaxation of rat basilar artery

Background and aim

Hyperin, a flavonol compound extracted from the Chinese herb Abelmoschus manihot L. Medic, is reported to exert protective actions in cerebral ischemic injury. The specific aim of the present study was to study the relaxation of Hyperin in rat isolated basilar artery and identify the underlying cellular mechanisms.

Methods

Rat isolated basilar artery segments were cannulated and perfused while being superfused with PSS solution. Vessel images were recorded by video microscopy and diameters measured. Membrane potential was recorded using glass microelectrodes to evaluate the basilar artery smooth muscle cell hyperpolarization.

Results

Perfusion of Hyperin (1 ~ 100 μM) elicited a concentration-dependent relaxation of basilar artery segments preconstricted with 0.1 μM U46619. The response was significantly inhibited by the removal of the endothelium. Hyperin also elicited marked and concentration-dependent hyperpolarization of smooth muscle cells. 30 μM nitro-L-arginine (an inhibitor of nitric oxide synthase) and indomethacin (an inhibitor of cyclooxygenase), partially inhibited Hyperin-induced relaxation and hyperpolarization leaving an attenuated, but significant, endothelium-dependent relaxation and hyperpolarization. This remaining effect was almost completely blocked by 1 mM tetraethylammonium (an inhibitor of Ca²⁺-activated K⁺ channels), or by 100 μM DL-propargylglycine, an inhibitor of cystathionine-γ-lyase (a synthase of the endogenous H₂S).

Conclusion

These findings show that Hyperin produces significant hyperpolarization in rat basilar artery smooth muscle cells and relaxation through both endothelium-dependent and endothelium-independent mechanisms. The underlying mechanisms appeared to be multi-factorial involving nitric oxide, prostacyclin, and endothelium-derived hyperpolarizing factor (EDHF). Our data further suggest that endogenous H₂S is a component of the EDHF-mediated hyperpolarization and relaxation to Hyperin.     

Plant antifreeze proteins and their expression regulatory mechanism

Low temperature is one of the major limiting environmental factors which constitutes the growth, development,productivity and distribution of plants. Over the past several years, the proteins and genes associated with freezing resistance of plants have been widely studied. The recent progress of domestic and foreign research on plant antifreeze proteins and the identification and characterization of plant antifreeze protein genes, especially on expression regulatory mechanism of plant antifreeze proteins are reviewed in this paper. Finally, some unsolved problems and the trend of research in physiological functions and gene expression regulatory mechanism of plant antifreeze proteins are discussed.