两种消浪树种幼苗光合特性对模拟潮汐水淹的响应

滨海滩涂消浪林是沿海防护林体系的重要组成部分,在消浪护岸、促淤保滩、防御来自海洋自然灾害等方面具有不可代替的作用。本研究以中亚热带两种木本消浪植物海滨木槿（Hibiscus hamabo）和蜡杨梅（Myrica cerifera）为研究对象,模拟海水水淹,系统研究了不同海水水淹程度下两木本植物光合特性的响应规律。结果发现,随着水淹胁迫的增加,海滨木槿最大净光合速率逐渐下降、光补偿点逐渐增加,表观量子效率在7、21天时先降低后增加,后期呈现逐渐降低的趋势,说明胁迫初期通过增加光合利用率来适应水淹胁迫,暗呼吸速率在7、21天逐渐增加,而在42、70天时W8（水淹8 h,水深45 cm）处理显著小于其它处理,说明W8处理已显著影响了该树种的光合特征;蜡杨梅最大净光合速率、表观量子效率表现为逐渐降低的趋势,而光补偿点和暗呼吸速率则逐渐增加,42天后W6（水淹6 h,水深35 cm）、W8处理各项指标显著小于其它处理。经多元方差分析发现,水淹21天内海滨木槿的光合指标要显著好于蜡杨梅,而在42天后则基本相同;海滨木槿在水淹胁迫6 h内可以生长,而蜡杨梅则只能在4 h内,这可为消浪林构建提供理论依据。     

Spatial/temporal variations in shrub thicket soil seed banks on an Atlantic Coast barrier island

Potential species replacement within low-diversity shrub thicket communities was investigated for a Virginia barrier island. Seed bank species composition was quantified in a glasshouse study using soil samples collected beneath closed Myrica cerifera thickets, as well as from thicket gaps. Samples were collected from productive and aging thickets, corresponding to differences in soil age. These data were compared to species presently occurring within the thickets and gaps. Seedbank species composition was not indicative of current community composition for either the intact thickets or the gaps. Seed banks resembled a more pioneer community. Thirteen families, 23 genera, and 25 species were identified from the seed bank beneath the M. cerifera thickets. Four species were woody. The within-gap seed bank included 19 families, 30 genera, and 34 species. Eight species were woody. The current community included 21 families, 33 genera, and 36 species beneath the intact thickets as well as within the thicket gaps. Eighteen species were woody. The species richness of gaps was more than three times that of intact thickets. For low-diversity shrub thickets, gaps enhance species richness.     

Biological Activities of Triterpenoids and Phenolic Compounds from Myrica cerifera Bark

Seven triterpenoids, 1  –  7 , two diarylheptanoids, 8 and 9 , four phenolic compounds, 10  –  13 , and three other compounds, 14  –  16 , were isolated from the hexane and MeOH extracts of the bark of Myrica cerifera L. (Myricaceae). Among these compounds, betulin ( 1 ), ursolic acid ( 3 ), and myricanol ( 8 ) exhibited cytotoxic activities against HL60 (leukemia), A549 (lung), and SK‐BR‐3 (breast) human cancer cell lines (IC₅₀ 3.1 – 24.2 μm ). Compound 8 induced apoptotic cell death in HL60 cells (IC₅₀ 5.3 μm ) upon evaluation of the apoptosis‐inducing activity by flow cytometric analysis and by Hoechst 33342 staining method. Western blot analysis on HL60 cells revealed that 8 activated caspases‐3, ‐8, and ‐9 suggesting that 8 induced apoptosis via both mitochondrial and death receptor pathways in HL60. Upon evaluation of the melanogenesis‐inhibitory activity in B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH), erythrodiol ( 7 ), 4‐hydroxy‐2‐methoxyphenyl β‐d ‐glucopyranoside ( 13 ), and butyl quinate ( 15 ) exhibited inhibitory effects (65.4 – 86.0% melanin content) with no, or almost no, toxicity to the cells (85.9 – 107.4% cell viability) at 100 μm concentration. In addition, 8 , myricanone ( 9 ), myricitrin ( 10 ), protocatechuic acid ( 11 ), and gallic acid ( 12 ) revealed potent DPPH radical‐scavenging activities (IC₅₀ 6.9 – 20.5 μm ).     

The capacity of Jamaican mine spoils, agricultural and forest soils to nodulate Myrica cerifera, Leucaena leucocephala and Casuarina cunninghamiana

Soils from seven sites on the island of Jamaica were assayed for the symbiotic diazotrophs Frankia and Rhizobium using serial dilutions. Most probable number and least squares regression methods were used to estimate each soil's capacity to nodulate native Myrica cerifera, exotic Leucaena leucocephala and exotic Casuarina cunninghamiana. The sample sites included a montane forest, a slash-and-burn agricultural site, reclaimed bauxite mining areas, abandoned sugar cane fields, and a garden plot. None of the host plants used in the bioassay were present on the sites sampled except for scattered L. leucocephala on one site. Frankia capable of nodulating M. cerifera, which is native to Jamaican highlands, occurred at all sites sampled. No C. cunninghamiana-infective Frankia was detected in soils sampled. Only soils from one site on the tropical coastal plain harbored rhizobia able to nodulate L. leucocephala (37 nodulation units cm^?3 of soil). A subset of nodulated M. cerifera and L. leucocephala reduced acetylene to ethylene indicating nitrogenase activity. The slash-and-burn agricultural site, which was situated at an elevation of 200 m and possessed both high natural fertility and high soil moisture-supplying capacity, had significantly greater Myrica infectious capacity (1 000 nodulation units cm^?3 of soil) than the other sites (7?207 nodulation units cm^?3 of soil). A planned, paired comparison revealed that a recently cultivated sugar cane field and a recently reclaimed bauxite mining site together had significantly less Myrica-infective Frankia (4 nodulation units cm^?3 of soil) than a corresponding pair of sites consisting of a sugar cane field abandoned for 25 years and a bauxite mining site reclaimed 20 years before sampling (118 nodulation units cm^?3 of soil). Results indicate that Myrica-infective Frankia is widespread in Jamaica, that the number of Myrica-infective Frankia units vary from site to site in accordance with soil type and soil history, that Jamaican sites sampled lack soil Frankia populations capable of nodulating a casuarina host, that rhizobial symbionts capable of nodulating L. leucocephala may be geographically restricted to lowlands in Jamaica, and that the occurrence of Frankia in these soils is independent of host plant presence.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

医疗机构合理用药评价模型的构建研究

目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。     

棉铃虫钙粘蛋白N端多肽多克隆抗体制备及对Bt抗性的初步检测

用重组表达的棉铃虫Helicoverpa armigera(Hübner)中肠钙粘蛋白N端多肽片段制备兔多克隆抗体,并利用其对Bt抗性进行鉴定。通过RT-PCR方法对棉铃虫中肠钙粘蛋白N端多肽的基因片段Cad285进行PCR扩增,将其克隆到pET-30a原核表达载体中,在大肠杆菌BL21(DE3)中经IPTG诱导表达,得到35ku的重组融和蛋白,融合表达的包涵体经过变性、Ni-NTA柱亲和纯化、复性等方法处理包涵体,获得可溶性纯化蛋白,用纯化后蛋白免疫新西兰兔制备多克隆抗体,ELISA检测其效价高于1∶16000;利用最终获得的多克隆抗体对室内纯合Bt抗/感品系的棉铃虫中肠钙粘蛋白进行Western blot分析,结果显示敏感和抗性品系之间有明显差异,表明其能够应用对Bt抗性进行初步检测。     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

青蒿素生物合成机理研究现状

本文总结了目前有关青蒿素生物合成机理方面的研究,主要包括青蒿素生物合成中生理因子的影响,青蒿素生物合成中间体及前体,青蒿素生物合成细胞定位等。指出了存在的一些问题及今后的研究发展前景。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.     

基于医疗服务绩效信息透明的质量促进效果研究综述

利用描述性综述的方法,总结近10年来医疗服务绩效信息透明对医疗质量促进效果,根据纳入排除标准检索Web of Knowledge、Pubmed等数据库,最终纳入31篇密切相关文献。结果表明,国外一般通过医疗报告卡或网站向公众公开医疗服务绩效信息,改善了医疗服务行为,但对病人选择服务提供者和临床结果的改善作用有限。我国应制定相关政策,推动医疗服务绩效信息向更广泛的使用者公开,引导病人利用医疗服务绩效信息选择医疗服务提供者。