超声提取-分光光度法测定远志总皂苷的含量

目的:超声提取远志总皂苷,并用分光光度计进行总皂苷含量的测定.方法:超声提取远志总皂苷,以远志皂苷元为对照品,香草醛-冰醋酸-高氯酸为显色剂,采用分光光度法在585 nm处测定远志总皂甙含量.结果:对照品在28～63 μg范围内线性良好(r2=0.9984),平均回收率为100.45%,RSD=1.59%(n=5).超声提取和热回流提取的远志总皂苷含量分别为1.63%,1.50%.结论:超声提取法用时短,提取率高,能达到比传统回流法更理想的效果.分光光度法测定含量简便、快速、准确、可靠.     

细叶香茶菜中两个新的对映-贝壳杉烷二萜化合物

从云南中甸产细叶香茶菜(Isodon tenuifolia (W. W. Smith) Kudo)的地上部分分离得到6个化合物, 它们的结构通过波谱方法得到鉴定。其中化合物1和2为新的对映-贝壳杉烷二萜化合物, 即细叶香茶菜甲素(3β,6α,15β-trihydroxy-1α,7β-diacetoxy-11β,16β-epoxy-ent-kaurane) (1) 和细叶香茶菜乙素(1α,6α,11β-trihydroxy-3β,7β-diacetoxy-ent-kaur-16-en-15-one) (2)。     

Utilization of UPLC/Q‐TOF‐MS‐Based Metabolomics and AFLP‐Based Marker‐Assisted Selection to Facilitate/Assist Conventional Breeding of Polygala tenuifolia

As one of the most important traditional Chinese medicine, the quality of Polygala tenuifolia is difficult to control and a new method must be established to facilitate/assist the breeding of P. tenuifolia. In this study, UPLC/Q‐TOF‐MS‐based metabolomics analysis was performed to determine the chemical composition and screen metabolite biomarkers according to agronomic traits. A total of 29 compounds and 18 metabolite biomarkers were found. AFLP‐based marker‐assisted selection (MAS) was used to identify molecular marker bands and screen characteristic bands associated with specific agronomic traits. 184 bands and 76 characteristic AFLP bands were found. The correlation network between compounds and characteristic AFLP bands was built, so we may directly breed certain P. tenuifolia herbs with special agronomic traits (or characteristic AFLP bands), which exhibit specific pharmacological functions depending on the content of the active compounds. The proposed method of metabolomics coupled with MAS could facilitate/assist the breeding of P. tenuifolia.     

Glacial refugia and postglacial expansion of the alpine–prealpine plant species Polygala chamaebuxus

The shrubby milkwort (Polygala chamaebuxus L.) is widely distributed in the Alps, but occurs also in the lower mountain ranges of Central Europe such as the Franconian Jura or the Bohemian uplands. Populations in these regions may either originate from glacial survival or from postglacial recolonization. In this study, we analyzed 30 populations of P. chamaebuxus from the whole distribution range using AFLP (Amplified Fragment Length Polymorphism) analysis to identify glacial refugia and to illuminate the origin of P. chamaebuxus in the lower mountain ranges of Central Europe. Genetic variation and the number of rare fragments within populations were highest in populations from the central part of the distribution range, especially in the Southern Alps (from the Tessin Alps and the Prealps of Lugano to the Triglav Massiv) and in the middle part of the northern Alps. These regions may have served, in accordance with previous studies, as long‐term refugia for the glacial survival of the species. The geographic pattern of genetic variation, as revealed by analysis of molecular variance, Bayesian cluster analysis and a PopGraph genetic network was, however, only weak. Instead of postglacial recolonization from only few long‐term refugia, which would have resulted in deeper genetic splits within the data set, broad waves of postglacial expansion from several short‐term isolated populations in the center to the actual periphery of the distribution range seem to be the scenario explaining the observed pattern of genetic variation most likely. The populations from the lower mountain ranges in Central Europe were more closely related to the populations from the southwestern and northern than from the nearby eastern Alps. Although glacial survival in the Bohemian uplands cannot fully be excluded, P. chamaebuxus seems to have immigrated postglacially from the southwestern or central‐northern parts of the Alps into these regions during the expansion of the pine forests in the early Holocene.     

Allele frequencies, genetic relationships and heterozygosity in Poly gala vulgaris populations from contrasting habitats in southern Britain

Polygala vulgaris is a widespread perennial plant species of basic to neutral grassland throughout Britain. It is variable in flower colour and some vegetative characters in most populations. Gene flow is restricted in all populations since the plants are normally self-pollinating (up to 20% outcrossing, calculated from figures of heterozygosity) and seeds are normally dispersed only up to 2 m from the parent plant. Examination of several enzyme systems, using starch gel electrophoresis, showed that all enzyme loci appeared to have been duplicated, probably owing to the fact that P. vulgaris is a tctraploid in a genus which has primarily diploid members in Europe. Polymorphisms were found at both of the duplicated loci in four enzyme systems and at one locus in each of two further systems. Fifty-one populations from a diversity of habitats were sampled in southern Britain. In most populations from the typical habitat of lowland calcareous grassland, polymorphisms occurred at five or more loci, and the alleles were distributed throughout the populations. In all these sites there was a diversity of microhabitat and, in one area, marked differences in microhabitat distribution between different enzyme morphs. It is likely that differential selection is an important factor in the maintenance of the polymorphisms in all these areas. These populations were divided, genetically, into two main groups, those from the Gower peninsula, South Wales, and those from the English chalk. Within each group the populations were quite closely related genetically, though some large differences at particular loci occurred even between adjacent populations. Diffuse clumps of alleles occurred within all these populations, and it is likely that limited gene flow has affected the genetic structure of the populations, particularly since cycles of local extinction and recolonization are likely to be recurring. The genetic structure of each population, at the allozyme loci examined, is likely to be the consequence of a balance between differential selection and restricted gene flow. The number of heterozygotes was small, though higher than expected from an analysis of experimental progeny, suggesting a hcterozygotc advantage. Few strong multilocus associations were found despite the predominance of self-pollination. In the populations from sand dunes, roadsides, submontane grassland and water meadows there was, in general, much less polymorphism than in those from lowland calcareous grassland and some populations were entirely monomorphic; in most others there were large, entirely monomorphic groups of plants. Genetic distances between these populations were variable, even within one habitat and area, and they did not appear to show any particular relationship to each other. It is likely that the genetic structure of these populations, at the loci studied, has arisen largely through chance colonizations and genetic drift.     

富含11-廿碳烯酸的黄花倒水莲种子油

应用气相色谱和色谱-质谱方法分析鉴定了黄花倒水莲种子油的脂肪酸成分,其脂肪酸组成（％）为癸酸0．3,月挂酸0．3,肉豆蔻酸0．1,棕榈酸1．9,硬脂酸2．3,花生酸2．6,油酸3.8,11-廿碳烯酸88.5．一个未鉴定成分0．2．远志科植物中出现高含量的11-廿碳烯酸属首次报道。     

Four years host–parasitoid food web: testing sampling effort on trophic levels

Incomplete sampling is a major problem affecting data quality with respect to food webs. We described a host–parasitoid food web based on data from four years of sampling, evaluated the dataset robustness of the food web, and tested the hypothesis that different trophic levels require different sampling efforts. We sampled Senegalia tenuifolia fruits at eight sampling sites in three areas, during four years (2011–2014) in the Brazilian cerrado (savanna). We recorded 26 insect species in three trophic levels associated with S. tenuifolia. For species accumulation curves, all insect trophic levels, areas and years reached the asymptote, except for one area. The cumulative species richness in each trophic level suggested that the third level (primary parasitoid) should be sampled for a longer time than the second and fourth levels, supporting our hypothesis. In conclusion, the sampling effort employed was sufficient to assess most of the insect species richness, and provided a high-quality and well-represented host-parasitoid food web, even though trophic levels require different efforts.     

Investigation of Microbes in the Rhizosphere of Selected Grasses for Rhizoremediation of Hydrocarbon-Contaminated Soils

Hydrocarbon-degrading microorganisms (HDM) associated with the rhizosphere of Paspalum vaginatum and Zoysia tenuifolia grown in bioremediated soil were isolated under controlled laboratory conditions. The isolation process was conducted at 30°C and 45°C to isolate mesophilic and thermotolerant microorganisms, respectively, under aerobic conditions. The isolated HDMs were identified using 16S rRNA gene sequencing and fatty acid methyl ester (FAME) analysis. Although differences in the genera of the isolated HDMs occurred between the two grasses, Arthrobacter spp and Bacillus spp were isolated from the rhizosphere of both plants. The efficiency of the isolated microorganisms in degrading a mixture of hydrocarbon compounds (HC) was also assessed. Among the bacterial isolates, Pseudomonas boreopolis was found to be the most effective HC degrader, while the only fungal isolate, Fusarium solani, demonstrated higher degradation rates than most of the bacterial isolates. A mixture of all the microbial isolates demonstrated a high degradation percent of HC. The isolated microorganisms thus appear to work synergistically to degrade efficiently all the tested organic compounds.     

Chemical Composition and Antimicrobial Activity of Achillea tenuifolia Lam. Essential Oil at Different Phenological Stages from Khoy

Achillea species and in particular Achillea tenuifolia Lam . is generally used as a food flavor and traditional remedies, especially in the initial developmental stage for medical conditions in the Mediterranean part of Iran. In this report, we extracted the essential oil from the aerial parts of A. tenuifolia (collected from Khoy), at various developmental stages (i. e., vegetative, flowering and fruiting), characterized them and studied their antibacterial activities. Of 46, 51 and 38 components found in the vegetative, flowering, and fruiting stages, respectively, 35 were present in all three stages, including oxygenated terpenes such as carvacrol (30.85–34.11), germacrene C (16.21–17.87), spathulenol (7.26–8.96), β‐sesquiphellandrene (4.11–4.25), τ‐muurolol (2.27–3.25) and α‐cadinol (2.01–3.29). We witnessed that the composition of the essential oils varies with phenological stages and geographic regions. The essential oil demonstrated substantial antibacterial properties against both Gram‐positive and Gram‐negative bacteria, indicated by disk method, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays. Except Pseudomonas aeruginosa, the essential oils of various phenological stages showed higher antibacterial activity against tested bacteria, with Bacillus anthracis as the most sensitive strain. Moreover, although antibacterial characteristics of the essential oil from the vegetative and flowering stages were similar (p=0.91), they were significantly different from those of fruiting stage (p<0.005 in both MIC and MBC tests). This emphasizes the importance of the developmental stage of the plant in the biological properties of its essential oil and justifies the widespread application of this plant in the vegetative stage.     

The Worldwide Spread,Success, and Impact of Ragweed (Ambrosia spp.)

The Ambrosia species represent one of the most problematic groups of invasive weeds around the world. The ease with which they are introduced and spread in new countries, their generalist ecological requirements, and functional traits facilitate their invasion and subsequent naturalization in new areas. All of these aspects contribute to increasing their global social and economic impact, which is mostly related to pollen allergy. Here we analyze available scientific publications about Ambrosia artemisiifolia, A. psilostachya, A. tenuifolia, and A. trifida, with the aim of defining the current level of knowledge and summarizing important data that are currently scattered throughout the literature. Specifically, we analyzed the following: (1) their current global distribution and current stage of invasion; (2) traits and requirements promoting their introduction, reproductive success, and adaptation to climate and environment in the nonnative range; as well as (3) current knowledge about allergens and elements increasing their impact.