沙枣（Elaeagnus angustifolia L.）的胚和胚乳发育

本文报道了沙枣受精前后,胚囊的结构和胚珠、胚囊中组织化学变化,以及胚和胚乳的发育,胚乳母细胞早于受精卵发育。为核型胚乳,胚乳发育早期,胚囊中富含蛋白质,胚胎发育为紫苑型,当多细胞原胚吋,胚乳开始形成细胞壁,胚细胞中含少量淀粉粒和可溶性蛋白质,这时候,胚柄极为发达,心形胚时,胚乳巳全部形成细胞壁,但局限于胚囊边缘,鱼雷形胚时,胚柄开始退化。以后,随着子叶的发育和生长,胚乳渐被吸入,接近成胚期,胚已为发达的子叶所取代,沙枣为无胚乳种子,成胚的子叶发达,于基部外方具一舌状物。     

Trixis angustifolia hexanic extract displays synergistic antibacterial activity against M. tuberculosis

A phytochemical and antibacterial study of Trixis angustifolia, a species endemic to Mexico, was performed allowing the isolation of six flavones. The minimal inhibitory concentration (MIC) of the hexanic extract, against Mycobacterium tuberculosis H37Rv was 25 μg/mL. The hexanic extract caused a significant inhibition of intracellular mycobacterial growth at 12.5 μg/mL. The biodirected assay of hexane extract enabled the detection of an active fraction (AF) against M. tuberculosis (MIC = 12.5 μg/mL), and a major flavone 1 (pebrellin) with no antimycobacterial activity (MIC > 200 μg/mL). A subsequent combination antimicrobial assay showed a synergistic antimycobacterial effect of AF in combination with pebrellin; the results of the synergistic activity suggest that the antimycobacterial activity found in T. angustifolia is due to the combined action of diverse metabolites present in the plant.     

Adulteration of Essential Oils: A Multitask Issue for Quality Control. Three Case Studies: Lavandula angustifolia Mill., Citrus limon (L.) Osbeck and Melaleuca alternifolia (Maiden & Betche) Cheel

The quality control of essential oils (EO) principally aims at revealing the presence of adulterations and at quantifying compounds that are limited by law by evaluating EO chemical compositions, usually in terms of the normalised relative abundance of selected markers, for comparison to reference values reported in pharmacopoeias and/or international norms. Common adulterations of EO consist of the addition of cheaper EO or synthetic materials. This adulteration can be detected by calculating the percent normalised areas of selected markers or the enantiomeric composition of chiral components. The dilution of the EO with vegetable oils is another type of adulteration. This adulteration is quite devious, as it modifies neither the qualitative composition of the resulting EO nor the marker’s normalised percentage abundance, which is no longer diagnostic, and an absolute quantitative analysis is required. This study aims at verifying the application of the two above approaches (i.e., normalised relative abundance and absolute quantitation) to detect EO adulterations, with examples involving selected commercial EO (lavender, bergamot and tea tree) adulterated with synthetic components, EO of different origin and lower economical values and heavy vegetable oils. The results show that absolute quantitation is necessary to highlight adulteration with heavy vegetable oils, providing that a reference quantitative profile is available.     

滹沱河湿地狭叶香蒲群落生物量研究

研究了山西滹沱河湿地狭叶香蒲群落的结构和生物量,结果表明狭叶香蒲群落的总生物量为７０７６ｋｇ／ｈｍ＾２,其中地上部分（叶、茎等）为２５８９．８ｋｇ／ｈｍ＾２,地下部分（根）为４４８６．２ｋｇ／ｈｍ＾２。建群种狭叶香蒲的生物量为５５１３．５ｋｇ／ｈｍ＾２,其中地上部分（叶、茎等）为１７２５．６ｋｇ／ｈｍ＾２,地下部分（根）为３８０５．９ｋｇ／ｈｍ＾２,占群落总生物量的７７．９２％。优势种披针苔草和狼     

三江平原小叶章湿地土壤的CO2通量

采用密闭箱动态测量法对三江平原小叶章典型湿地土壤CO2通量进行了研究.结果表明,小叶章湿地土壤CO2通量有明显的季节变化和日变化,并且呈现出一定的规律性.7～10月,土壤CO2通量呈现出季节变化的单峰模式.在1d的观测期间,土壤CO2通量从早晨开始增大,到午后达到极大值,后逐渐降低到第2天凌晨达极小值,然后又开始增加.研究同时表明小叶章湿地土壤CO2通量的主要影响因素为地温(相关系数为0.7699).而因湿地环境土壤水分充足,土壤含水量对土壤CO2通量的影响不明显,当土壤水分不成为限制因素时,土壤CO2通量与土壤温度呈正相关.根据测量结果,小叶章湿地土壤CO2通量在整个测量期间的变化范围为0.208～1.265g/(m2*h),平均水平为0.619g/(m2*h).     

抗逆性灌木树种--银莓的引种及抗性评价

银莓Elaeagnus commutataBernh(silverberry)是加拿大和北美大部分地区的乡土灌木树种,具有抗风沙、抗干旱、耐瘠薄、耐盐碱、耐寒等多项优良特性.从银莓的种子处理、苗木培育、田间抗逆性试验、组织培养及营养成分分析等几方面入手,对银莓在吉林省西部引种试验的研究现状及初步结果进行了报道.研究结果表明:银莓可在吉林省安全过冬,具有较强的抗逆性,可以作为吉林省西部荒漠化治理和生态工程建设的一种较为理想的引进灌木树种.     

红缘天牛对沙枣花中8种化合物的EAG及行为反应

为了研究沙枣花对红缘天牛的引诱效果,采用GC-MS技术分析出沙枣花挥发物含有47种化合物.选取相对分子质量在100~300之间的8种化合物,分别采用单一组分和多组分混合配方对红缘天牛进行EAG和嗅觉行为实验.结果表明:(1)在单一组分不同浓度的EAG实验中,红缘天牛对肉桂酸乙酯的反应最为强烈,且当质量分数为1.00%时红缘天牛的EAG相对反应值最大,除肉桂酸甲酯和愈创木酚反应不明显外,其他化合物均在质量分数为1.00%时EAG反应活性最高;(2)嗅觉行为反应中,红缘天牛对单一组分的8种化合物相对选择率均在质量分数1.00%时最高;(3)邻苯二甲酸二甲酯、肉桂酸乙酯、癸酸酯、芳樟醇、肉豆蔻酸异丙酯和4,4-亚甲基(2,6-叔丁基苯酚)这6种化合物配制成21种混合物,其中配方P、Q在EAG和嗅觉行为反应中效果均较好,这说明邻苯二甲酸二甲酯、肉豆蔻酸异丙酯、肉桂酸乙酯、癸酸酯、芳樟醇这5种化合物在一定的配比情况下对红缘天牛有较好的引诱活性.     

沙枣（Elaeagnus angustifolia L．）在黄河三角洲盐碱地的应用前景

黄河三角洲是我国三大三角洲之一,总面积达5．4×105 hm2,其中盐碱地面积达70％以上,并且仍在以每年1．3×105 hm2的速度增加．黄河三角洲地区土地盐碱化程度高,夏季降雨集中,春秋季较干旱,这些不利的环境因素导致该地区生态环境比较脆弱,绿化造林难度大,植被覆盖面积小,当地的景观生态系统比较单一．因此,筛选优质抗盐碱树种并建立一套完整的绿化栽培体系,以提高黄河三角洲地区的绿化面积是现在所面临的严峻问题．沙枣由于抗旱耐盐碱成为改良黄河三角洲地区的绿化树种,本文综述了沙枣作为黄河三角洲地区盐碱地绿化树种的应用前景．     

狭叶獐牙菜化学成分研究

目的:研究狭叶獐牙菜的主要化学成分。方法:采用硅胶柱层析分离纯化化合物,依据理化性质和现代波谱技术进行结构鉴定。结果 :从氯仿部位分离鉴定了4个单体化合物,分别为:齐墩果酸(1)、乌苏酸(2)、羽扇豆醇(3)、3β-羟基-11α,12α-环氧齐敦果-28,13β-内酯(4)。结论:除化合物(1)外,化合物(2)、(3)、(4)为首次从该药用植物中分离得到。