不同产地蒙古黄芪矿物元素比较研究

无机元素与药材的药效密切相关,其通过对次生代谢途径中各种酶活性的调节作用而影响中药中次生代谢产物的合成,是中药质量控制不可或缺的特征参数。为有效鉴别蒙古黄芪产地和品质差异,找出蒙古黄芪的特征元素及其与产地的关系。实验采用电感耦合等离子体发射光谱(ICP-OES)测定青海省不同产地蒙古黄芪无机元素的种类与含量,分别用S PSS 22.0和R包对数据进行聚类分析和主成分分析。测定了黄芪中的12种元素,主成分分析结果显示Ca,Fe,Li,P,K,Mg,Zn,AL,Na元素为蒙古黄芪的特征元素。聚类结果表明不同产地的蒙古黄芪样品中无机元素的种类和含量与产地有一定的关联性,当欧氏距离为8时,可聚为三大类,S12为一类,S1,S2,S4,S5,S6,S7,S10,S 11,S13,S16聚为一类,其余的产地聚为一类,结合ArcGIS样点分布图,可更为直观地看出产地与其品质的关系。此外,建立了蒙古黄芪中无机元素的分布特征图谱,不同产地蒙古黄芪无机元素特征图谱相似度均为0.996以上,因此可结合指纹图谱对不同产地的蒙古黄芪进行识别分析。从无机元素含量的主成分分析结果来看,产于S10(互助县东沟乡纳卡村)的黄芪质量最优,总因子得分值F最高,其次是S7和S8,可见,互助县整体蒙古黄芪的品质较好。结果表明蒙古黄芪具有丰富的矿物元素,其含量受产地影响,关注药材中元素的含量和种类,不仅是对药理成分的补充说明,更能从元素角度进一步揭示其品质优劣,研究结果为蒙古黄芪的资源开发利用及品质鉴定提供参考依据,为蒙古黄芪的质量安全控制提供保障。

6种干燥方法对麻花艽品质的影响

目的研究6种干燥方法对麻花艽品质的影响。方法测定干燥时间、折干率、外观色泽。采用自然晒干、自然阴干、杀青后阴干、100℃烘干、微波干燥、冷冻干燥6种干燥方法,HPLC法测定龙胆苦苷、马钱苷酸、6′⁃O⁃β⁃葡萄糖基龙胆苦苷、獐牙菜苦苷、獐牙菜苷含量,采用层次分析法进行综合评价。结果微波干燥、冷冻干燥、杀青后阴干下龙胆苦苷、5种成分总含量显著高于自然晒干、自然阴干、100℃烘干处理。结论考虑实际生产过程中耗时、耗能、设备要求,麻花艽最适合的干燥方法为杀青后阴干。

Aboveground biomass of the alpine shrub ecosystems in Three-River Source Region of the Tibetan Plateau

Though aboveground biomass(AGB) has an important contribution to the global carbon cycle,the information about storage and climatic effects of AGB is scare in Three-River Source Region(TRSR)shrub ecosystems. This study investigated AGB storage and its climatic controls in the TRSR alpine shrub ecosystems using data collected from 23 sites on the Tibetan Plateau from 2011 to 2013. We estimated the AGB storage(both shrub layer biomass and grass layer biomass) in the alpine shrubs as 37.49 Tg, with an average density of 1447.31 g m^(-2). Biomass was primarily accumulated in the shrub layer, which accounted for 92% of AGB, while the grass layer accounted for only 8%. AGB significantly increased with the mean annual temperature(P < 0.05). The effects of the mean annual precipitation on AGB were not significant. These results suggest that temperature,rather than precipitation, has significantly effects on of aboveground vegetation growth in the TRSR alpine shrub ecosystems. The actual and potential increase in AGB density was different due to global warming varies among different regions of the TRSR. We conclude that long-term monitoring of dynamic changes is necessary to improve the accuracy estimations of potential AGB carbon sequestration across the TRSR alpine shrub ecosystems.

Phylogenetic patterns of shrub communities along the longitudinal and latitudinal gradients on the northeastern Qinghai–Tibetan Plateau

Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mountain ecosystems.Shrubs comprise one of the main types of vegetation on the Qinghai–Tibetan Plateau,where they serve vital ecological functions.In this study,we used a community phylogenetic approach to examine the distribution patterns of shrub communities along the longitudinal and latitudinal gradients on the northeastern Qinghai–Tibetan Plateau.We observed significant latitudinal trends in both the phylogenetic diversity(PD)and net relatedness index(NRI)values of shrub communities,such that the former decreased and the latter increased with increasing latitude.However,no significant PD,NRI and nearest taxon index(NTI)distribution patterns were observed along a longitudinal gradient.A further analysis revealed that the combination of temperature-related and precipitation-related climate variables most strongly affected the PD,NRI and NTI values of shrub communities,indicating that the latitudinal patterns in the PD,NRI and NTI of a shrub community may be determined mainly by interactions with these climate factors.

坡位对高寒灌丛群落谱系多样性和谱系结构的影响

群落谱系信息是生物多样性研究的主要内容之一,坡位是影响群落物种组成的重要地形因素,因此,研究坡位与群落谱系多样性和谱系结构的关系对于提高我们对群落谱系多样性分布规律及群落构建机制的理解具有重要意义。本研究以青藏高原东北部(青海省)高寒灌丛为对象,分析了高寒灌丛群落中草本植物群落、木本植物群落以及灌丛群落整体的谱系多样性及群落谱系结构随坡位变化的规律及其影响因素。结果表明:草本植物群落和灌丛群落整体谱系多样性随坡位的下降均表现出单峰变化规律,在中部坡位谱系多样性最高,而灌丛木本植物群落的谱系多样性、灌丛群落(草本群落、木本群落及灌丛群落整体)的谱系结构无显著变化规律。将土壤理化因子(土壤全氮、全磷、pH和土壤含水量)与群落谱系多样性和谱系结构进行多元回归分析,发现土壤理化因子对群落谱系多样性的解释能力显著高于群落谱系结构,土壤含水量对草本植物群落和灌丛群落整体的谱系多样性影响极为显著。综上所述,坡位主要通过改变草本植物群落而不是木本植物群落物种组成来影响灌丛群落谱系多样性,而群落谱系结构受坡位影响较小。