岭南垛基果林湿地土壤碳组分特征

岭南垛基果林湿地是珠三角地区典型的湿地类型之一,其对土壤碳汇的贡献值得关注。为探讨果林种植类型对土壤有机碳的影响,对广州垛基果林湿地内种植黄皮(Clausenalansium)(HP),龙眼(Dimocarpuslongan)(LY)、杨桃(Averrhoa carambola)(YT),龙眼和黄皮间种(LH),杨桃、龙眼和黄皮间种(YLH)共5种种植类型下的表层(0～20 cm)土壤碳组分进行研究。结果表明,不同的植被类型对土壤的总有机碳(SOC)、可溶性有机碳(DOC)、微生物生物量碳(MBC)、易氧化有机碳(ROC)、惰性碳(NLC)含量都有影响,LY的SOC含量最高(22.6 g/kg),显著高于YLH (P<0.05),且NLC含量显著高于LH和YLH (P<0.05)。NLC含量与土壤养分呈正相关,与土壤容重呈负相关。YT的MBC含量显著高于LY、HP、LH (P<0.05),且MBC/SOC显著高于HP、LY(P<0.05)。YLH模式下,土壤DOC含量和DOC/SOC显著高于其他植被类型(P<0.05)。LH的ROC/SOC显著高于HP和L...     

基于转录组测序的宁夏枸杞不同品种果实活性成分合成差异表达基因分析

为探究不同品种宁夏枸杞果实活性成分生物合成相关基因的表达水平,筛选关键差异表达基因(differentially expressed genes,DEGs),揭示宁夏枸杞品种间活性成分含量差异的分子机制,本研究采用Illumina NovaSeq 6000高通量测序技术,对宁夏枸杞‘宁杞1号’和‘宁杞7号’青果期、转色期及成熟期果实进行转录组测序,比较2个品种果实不同发育期相关基因表达谱的变化。结果显示:转录组测序共获得811818178条clean reads,有121.76 Gb有效数据。‘宁杞1号’和‘宁杞7号’在青果期、转色期和成熟期差异表达基因分别有2827、2552和2311个;分别有2153、2050和1825个差异基因在基因本体论(gene ontology,GO)、京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)富集分析和同源蛋白簇(clusters of orthologous groups of proteins,KOG)分析等6个数据库中被成功注释。青果期、转色期和成熟期果实的差异表达基因,在GO数据库分别有1307、865和624个被富集到生物学过程、细胞组分及分子功能3个部分中;KEGG通路富集结果均集中在代谢途径、次生代谢物生物合成和植物-病原互作过程;在KOG数据库,3个发育期分别注释了1775、1751和1541个差异表达基因。对注释的基因进行PubMed数据库检索,在青果期、转色期和成熟期分别筛选到与枸杞活性成分合成相关的差异表达基因18、26和24个,这些基因主要参与类胡萝卜素、类黄酮、萜类、生物碱和维生素等代谢途径。选取7个差异表达基因进行RT-qPCR验证,结果与转录组测序数据表达趋势一致。本研究从转录水平为不同品种宁夏枸杞活性成分含量差异提供了初步证据,为进一步挖掘枸杞活性成分生物合成的关键基因及解析其表达调控机制提供了研究基础。     

白花蛇舌草的化学成分研究

为研究白花蛇舌草(Hedyotis diffusa)的化学成分,采用硅胶柱色谱、制备HPLC色谱等方法,从白花蛇舌草全草的70%乙醇提取物中分离得到9个化合物。根据理化性质及其波谱或光谱数据,结构分别鉴定为：豆甾醇(1)、β-谷甾醇(2)、rubiadin(3)、2,6-二羟基-1-甲氧基蒽醌(4)、β-谷甾醇-3-O-β-D-葡萄糖苷(5)、对香豆酸(6)、山奈酚(7)、槲皮素(8)和2-羟基-3-甲氧基-7-甲基蒽醌(9)。化合物4为新化合物;氯仿提取部位的Fr.4、Fr.4-2及Fr.4-4流分具有较强体外抗人子宫内膜癌Ishikawa细胞活性,其IC₅₀值分别为52.8、78.1和27.5μg/mL。     

Effect of Flowering Stages on the Content of Active Ingredients and Antioxidant Capability of Bletilla striata Flowers

Bletilla striata (Thunb.) Reichb.f. is a perennial herb with abundant active ingredients. Previous research mainly focused on its tubers, however, the study on flowers, especially the variation of active ingredient contents at different flowering stages, was rarely seen. This study analyzed the total phenols, flavonoids, polysaccharides, anthocyanins, and cyanidin-3-O-glucoside content of B. striata flowers which were in cultivated in Herb Garden of Zhejiang A&F University and collected in May, 2019, in order to investigate the changes in active ingredients and antioxidant capacity among different flowering stages (bud, initial, and full bloom). Changes in radical scavenging capability of DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), ABTS (2,2′-azinobis(3-ethylbenzthiazoline-6-sulphonate)), and hydroxy were analyzed. Significant differences in active ingredient content of flowers were detected among different flowering stages. The total phenolic content increased continuously during the entire flowering stage. The contents of total flavonoid, total polysaccharide, and cyanidin-3-O-glucoside reached peaks at the initial blooming stage and then fell as the flowering process continued. The antioxidant activity in initial stage was the highest than in any other flowering stages. Therefore, we conclude that the initial blooming stage is the best harvesting stage of B. striata flowers. This study provides a robust basis for the harvest and utilization of B. striata flowers in food, medical, and cosmetic industries.     

Chilling stress and oxygen metabolizing enzymes in Zea mays and Zea diploperennis*

Abstract. The activities of five active-oxygen scavenging enzymes were compared for cold-lability and three were compared for chilling induction in two Zea genotypes of contrasting susceptibility to photoinhibition during chilling. Activities of superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1), and glutathione reductase (GTR, EC 1.6.4.2) in leaf extracts from plants grown without chilling stress were assayed at 19°C and 5°C. Enzymes from the chilling-susceptible Z. Mays cv. LG11 had lower specific activities at 5°C than did enzymes from the chilling-tolerant Z. diploperennis, except for MDHAR where no significant differences were observed. The activities of SOD and APX from Z. diploperennis were double those of Z. mays at both assay temperatures. Monodehydroa-scrobate reductase and glutathione reductase activities in both species were reduced by 63–78% at a 5°C assay temperature. The dehydroascorbate reductase (DHAR) showed the greatest low-temperature lability losing 96% (Z. diploperennis) and 100% (Z. mays) of its activity at 5°C. To examine possible chilling-induced changes in levels of enzyme activity, plants of both Zea genotypes were transferred to growth chambers at 10°C at moderate light intensities. Glutathione reductase activity was found to increase within 24h in Z. diploperennis, but it decreased slightly in Z. mays. MDHAR activity decreased by 50% in Z. diploperennis but showed only a transient increase in activity in Z. mays.     

中药金樱子的研究应用概况

本文就国内外对中药金樱子的化学成分及其提取分离方法、药理学研究和临麻应用作了综述,为金樱子的综合开发提供依据。     

银木种内化学类型研究

毛细管气相色谱／质谱／计算机联用仪器分析结果表明,在四川省成都市一人工种植的银木（Ｃｉｎｎａｍｏｍｕｍｓｅｐｔｅｎｔｒｉｏｎａｌｅ）种群中,其枝叶精油主要化学组成在各植株间存在很大差异,发现精油存在１,８－桉叶油素,樟脑,异丁香酚甲醇和９－氧代橙花叔醇等四个化学类型．除异丁香酚甲醚类型外,其余类型均为第一次报道．综观樟属其它种的化学类型研究可见,化学类型在樟属植物中普遍存在种内多型性和种间共性．     

Prediction of the non-fertilizer N supply of mineral grassland soils

Different methods for estimating the non-fertilizer N supply (NFNS) of mineral grassland soils were compared. NFNS was defined as the N uptake on unfertilized plots. The potential mineralization rate (0–12 weeks), macroorganic matter and active microbial biomass (determined by the substrate-induced respiration method; SIR) were correlated positively with NFNS. The difference between the actual soil organic N or microbial N content (determined by the fumigation incubation method) and their contents under equilibrium conditions ( org. N and MB-N), however, gave the best estimations of NFNS. For field conditions the best estimation for NFNS was: NFNS (kg N ha^–1 yr^–1)=132.3+42.1× org. N (g kg^–1 soil; r=0.80). This method is based on the observation that, under old grassland swards, close relationships exist between soil texture and the amounts of soil organic N and microbial N. These relationships are assumed to represent equilibrium conditions as under old swards under constant management, the gain in soil organic N and microbial N equals the losses. Soils under young grassland and recently reclaimed soils contained less soil organic N and microbial N. In such soils the amounts of organic N and microbial N increase with time, which is reflected in a lower NFNS. The annual accumulation of organic and microbial N gradually becomes smaller until organic N, microbial N and NFNS reach equilibrium. The main advantage of the difference method in comparison with the other methods is its speed and simplicity.FAX no: +31 50337291     

IN VIVO MEASUREMENT OF ACTIVE OXYGEN PRODUCTION IN THE BROWN ALGA FUCUS EVANESCENS USING 2′,7′-DICHLOROHYDROFLUORESCEIN DIACETATE1

Intracellular production of active oxygen in the brown alga Fucus evanescens C. Ag. was studied by measuring the capacity for in vivo conversion of 2′,7′-dichlorohydrofluorescein diacetate (DCFH-DA) to the fluorescent dye 2′,7′-dichlorofluorescein (DCF), both in emersed and immersed seaweeds. Algae were incubated in seawater containing DCFH-DA under a range of conditions, and it was also possible to load algae with DCFH-DA and then follow subsequent DCF production in emersed tissue. DCF formation was linear for at least 2 h in both darkness and light, with the rate of formation increasing with the light level. DCF formation was temperature dependent. It also increased when algae were treated with H₂O₂ or methyl viologen (paraquat), which disrupts photosystem 1 electron transport and increases O^?₂ production. Exogenous catalase reduced in vivo DCF production, presumably by lowering cellular concentrations of H₂O₂. Hydrogen peroxide was released into the seawater by illuminated algae resulting in external dye conversion to DCF. However, this does not interfere with in vivo measurement of DCF by loaded, washed algae because DCF leakage appeared to be negligible. Internal DCF did not affect photosynthetic oxygen production relative to untreated controls. Overall, our data suggest that DCFH-DA is a potentially very useful probe for studying active oxygen metabolism in seaweeds subjected to environmental stresses.     

Synthesis of optically active diols using an efficient polymer bound cinchona alkaloid derivative

A new insoluble polymer containing a Cinchona alkaloid derivative has been synthesized and used as chiral ligand in the heterogeneous enantioselective dihydroxylation of olefins. It is shown that the enantioselectivity of the optically active diols obtained from both aliphatic and aromatic substrates is always comparable to that observed in the homogeneous phase under the same reaction conditions. A method for evaluating the enantiomeric excesses of the optically active products is also described. © 1995 Wiley-Liss, Inc.