紫茎泽兰的化学成分研究

为了解紫茎泽兰(Eupatorium adenophorum Spreng.)的化学成分,从其乙醇提取物中分离得到7 个化合物。通过波谱分析,分别鉴定为万寿菊苷(1)、7-O-(6-methoxykaempferol)-β-D-glucopranoside (2)、4'-甲基醚万寿菊苷(3)、3-O-(6-methoxykaempferol)-β-D-glucopranoside (4)、邻苯二甲酸二丁酯 (5)、邻苯二甲酸二(2-乙基)己酯 (6)、1,4-bis(2-benzoxazolyl)naphthalene (7)。其中化合物1~4 为首次从紫茎泽兰中分离得到。     

紫茎泽兰DNA的提取及AFLP反应体系的建立

以紫茎泽兰叶片为材料,用改进的CTAB法,在提取液中加入2%PVP40(V/V)、0.4%BME(V/V),提取到了高质量的基因组DNA,OD260/OD280在1.7~1.9之间,蛋白质、多酚类、多糖、RNA等去除较彻底,适于AFLP分析。通过对紫茎泽兰DNA提取、酶切连接、预扩增、选择性扩增等实验过程中各关键因素的比较研究,建立了一套优化的AFLP分子标记体系,得到了清晰的AFLP银染指纹图谱,实验结果重复性好。     

构建丝状真菌大片段基因组文库载体DNA的制备

载体DNA的制备是构建大片段基因组文库的关键步骤之一,高质量载体DNA受到酶切、脱磷等因素的影响,以载体pBHYG为材料,优化了限制性内切酶胁HindⅢ酶切和小牛肠碱性磷酸酶(CLAP)脱磷的作用条件,并在T4连接酶作用下自连,通过胶回收纯化制备了可用于进一步构建大片段基因组文库的线性载体DNA。     

紫茎泽兰微生物发酵生产木糖醇的工艺

木糖醇（ｘｙｌｉｔｏｌ）是一种天然五碳多元醇,存在于许多水果、蔬菜及蘑菇中,但含量均很低,其中以蘑菇（ＡｇａｒｉｃｕｓｃａｍｐｅｓｔｒｉｓＬ．ｅｘＦｒ．）含量较高,约为１００ｍｇ／ｋｇ（干重）;木糖醇也是一种常见的代谢中间体,存在于哺乳动物的碳水化合...     

紫茎泽兰化学成分的研究（Ⅰ）

从云南紫茎泽兰(Eupatorium aclenophorum Spreng)茎、叶中分出10个化合物,经波谱(IR,MS,~1H-NMR,~(13)C-NMR)分别鉴定为9-oxo-ageraphorone(Ⅰ),9β-hydroxy-ager-aphorone(Ⅱ),表木栓醇(epifriedelinol,Ⅲ),豆甾醇(stigmasterol,Ⅳ),正二十八烷酸(octa-cosanoic acid,V),β-胡萝卜甙(β-daucosterol,Ⅵ),邻羟基桂皮酸(O-hydroxy cinnamic acid,Ⅶ),阿魏酸(ferulic acid,Ⅷ),咖啡酸(caffeic acid,Ⅸ),2-异丙烯基-5-乙酰基-6-羟基苯骈呋喃的乙酰化物(2-isopropenyl-5-acetyl-6-hydroxybenzofuran acetate,Ⅹ)。化合物(Ⅲ～Ⅹ)均系首次从该植物中分离到。     

紫茎泽兰入侵前后抗虫物质含量差异及其对泽兰实蝇寄生的响应

【目的】紫茎泽兰是我国重要的入侵杂草,对我国生态环境和农、林、牧业造成重大危害。本研究通过比较紫茎泽兰原产地与入侵地种群地上部抗虫物质含量的差异及其对泽兰实蝇寄生的响应,为探明紫茎泽兰入侵种群持续扩张的化学生态机制提供依据。【方法】选取5个紫茎泽兰种群(3个中国云南种群:C1,C2,C3;2个墨西哥种群:M1,M2),比较原产地和入侵地种群地上部分碳氮比、单宁类(单宁酸、儿茶素、鞣花酸)和类黄酮物质(槲皮素、异槲皮素、山奈酚)含量差异,以及泽兰实蝇寄生前后这些抗虫物质的含量变化。【结果】入侵地种群地上部分碳氮比不同程度地低于原产地种群,茎秆部位差异最明显。紫茎泽兰入侵地种群的单宁类和类黄酮物质含量亦低于原产地种群,其中,芽尖部位单宁酸和儿茶素含量差异尤为明显,分别比原产地种群低26.4%和32.3%。泽兰实蝇寄生后,原产地和入侵地种群单宁类和类黄酮物质含量基本呈上升趋势,其中,M1种群寄生植株在虫瘿破膜前,儿茶素含量比未寄生植株升高了163.2%。【结论】紫茎泽兰入侵种群在抗虫特性方面产生了资源再分配的适应性变化,有利于其在新生境天敌缺乏条件下的持续扩张。虽然泽兰实蝇寄生会诱导紫茎泽兰原产地种群和入侵地种群抗虫物质的增加,但原产地种群增加的幅度更大,表明紫茎泽兰入侵后对专食性天敌胁迫的适应性明显下降。     

紫茎泽兰花的化学成分

从紫茎泽兰（ Ｅｕｐａｔｏｒｉｕｍ ａｄｅｎｏｐｈｏｒｕｍ ） 的花中分离得到１２ 个化合物, 其中紫茎泽兰内酯为一新的杜松烯类倍半萜内酯化合物, 其它为２ － 乙酰氧基－ ３ , ４ , ６ , １１ － 四去氢杜松烷－ ７ － 酮, ７ － 羰基泽兰酮, 克拉维醇, 丁香酚－ Ｏ－ β－ 吡喃葡萄糖甙, ５ , ４′－ 二羟基－ ３ ,６ － 二甲氧基－ ７ － Ｏ－ β－ 吡喃葡萄糖基黄酮, ５ , ４′－ 二羟基－ ６ ,７ － 二甲氧基－ ３ － Ｏ－ β－ 吡喃葡萄糖基黄酮,３ , ５ , ４′－ 三羟基－ ６ ,７ － 二甲氧基黄酮等化合物。     

紫茎泽兰醇提物的毒理学研究

为确保以紫茎泽兰提取物为主要原药的植物源农药的安全性,对紫茎泽兰醇提物进行了小鼠经口急性毒性试验、大白兔急性皮肤和眼刺激试验、小鼠骨髓嗜多染红细胞微核计数及小鼠精子畸形试验等急性毒性和遗传毒性试验。结果表明,受试物对两种性别的小鼠经口急性毒性试验,LD50大于5000mg／kg,对大白兔皮肤无刺激性;小鼠骨髓嗜多染红细胞微核试验及小鼠精子畸形试验结果均为阴牲,受试物未见遗传毒性。     

外来入侵植物紫茎泽兰不同组织RNA提取方法

从植物组织中提取高质量的RNA是进行cDNA文库构建等分子生物学研究的前提。在苯酚法的基础上,改进并得到了一种适合紫茎泽兰根、茎、叶总RNA快速提取的方法,消除了蛋白质、DNA、多糖等的污染。该方法提取的紫茎泽兰不同组织总RNA纯度高、完整性好,可用于RT-PCR、cDNA文库构建、Northern杂交等分子生物学实验,而且简单、经济、重复性好,适合于多种植物组织总RNA的提取。Northern杂交表明F3’H基因在紫茎泽兰的根、茎、叶等组织中广泛存在,但在叶中的表达量最高,在根中的表达量最低。     

Invasive mechanism and control strategy of Ageratina adenophora (Sprengel)

In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation, the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion, interaction and competition between inter- and intra-species and community resistance, thereby providing important references to researches on other invasive alien species.     

Two new carene-type monoterpenes from aerial parts of Ageratina adenophora

Two new carene-type monoterpenes, (1α,6α,7α)-8-hydroxy-2-carene-10-oic acid (1) and (1α,6α)-10-hydroxy-3-carene-2-one (2), were isolated from the aerial parts of Ageratina adenophora, together with a known monoterpene, (−)-isochaminic acid (3). The new structures were elucidated on the basis of extensive spectroscopic analysis, including MS, 1D and 2D NMR techniques. Compound 3 was isolated from A. adenophora for the first time. Compounds 2 and 3 were found to show anti-fungal activity against spore germination of Magnaporthe grisea with IC₅₀ values 0.623 and 0.503 mM, respectively.     

入侵物种飞机草和紫茎泽兰的核型研究

报道了菊科（Asteraceae）原泽兰属（Eupatorium）2种植物的核型,飞机草(Chromolaena odorata (L.) R. M. King &; H. Robinson）2n=60,核型公式为2n=60=32 m+28 sm,核型属于“2A”型,紫茎泽兰(Ageratina adenophora (Sprengel) R. King &; H. Robinson）2n=51,核型公式为2n=51=30 m+21 sm,核型属于“2B”型。飞机草的染色体数目变化较大,紫茎泽兰染色体数目较稳定。紫茎泽兰不能产生正常的花粉。飞机草有性生殖产生的种子发芽率低,紫茎泽兰无融合生殖产生的种子发芽率高,但2种植物入侵能力都很强,种子数量与2种植物的入侵性关系不大。     

On the present and potential distribution of Ageratina adenophora (Asteraceae) in South Africa

Invasive alien plants pose a threat to biodiversity worldwide, and the costs of control are ever-escalating. Early detection and prediction of areas potentially at risk is crucial to minimise ecological and socio-economic costs. Maxent was used to predict the area within which Ageratina adenophora can potentially naturalise and spread in South Africa. The model was set up with 1020 occurrence records (10 replicates, 70% of records for calibration:30% for validation), and four climatic predictor variables. Background data were selected using Köppen–Geiger (vegetation-based) climate classification zones. All model replicates performed better than random in both binomial tests of omission and ROC analysis. The model was statistically significant and its mean AUC was 94%. The modeled prevalence was 0.21 and the sensitivity was 0.99. The Eastern Cape, KwaZulu-Natal, Mpumalanga and Gauteng provinces have climatic conditions indicative of a high potential for invasion by A. adenophora, followed by parts of the Western Cape, North West and Limpopo provinces. The model predicted areas beyond the current distribution, suggesting that A. adenophora has potential for further spread, and that searches for it need to be made beyond its currently known distribution. On the other hand it appears not to have spread into some climatically suitable areas near its current occupancy sites, such as throughout the KwaZulu-Natal mist belt, suggesting that unknown biotic (including human) or abiotic factors are also limiting its naturalization and require further study to be identified.     

Effects of leachates of the invasive plant, Ageratina adenophora (Sprengel) on soil microbial community

The invasive plant Ageratina adenophora (Sprengel) changed soil microbial communities in the invaded area to facilitate its growth and inhibit native plants. However, little is known about the driving forces underlying the alteration of soil biota. Leachates from root and aerial part (stem and leaves) of A. adenophora were mixed into soil to imitate field invasion processes for evaluation of its impact on invasion of soil microbial community. The results indicated that soil microbial community was significantly changed when the soil taken from the newly-invaded area was treated with A. adenophora root and aerial part leachates for 3 and 5 weeks, respectively. The biota of newly invaded soil treated with concentration of 100 mg/mL A.adenophora leachates was much closer to that of heavily invaded soil, but was significantly different from that of control soil (newly invaded soil without treatment). A.adenophora leachates promoted growth of the seven dominant rhizosphere bacterial species in the invaded soil. The effect of A.adenophora leachates on soil biota and dominant rhizosphere bacteria was positively correlated with the concentration of leachates, however, the effect of root leachates was stronger than the aerial part leachates. It is assumed that A.adenophora change soil microbial community via nutritional and chemical communication, which helps it in better colonization of the invaded soil.     

Activity of Stress-related Antioxidative Enzymes in the Invasive Plant Crofton Weed （Eupatorium adenophorum）

Crofton weed is an invasive weed in southwestern China. The activities of several antioxidative enzymes involved in plant protection against oxidative stress were assayed to determine physiological aspects of the crofton weed that might render the plant vulnerable to environmental stress. Stresses imposed on crofton weed were heat （progressively increasing temperatures： 25 ℃, 30 ℃, 35 ℃, 38℃ and 42 ℃ at 24 h intervals）, cold （progressively decreasing temperatures： 25 ℃, 20 ℃, 15℃, 10 ℃ and 5℃ at 24h intervals）, and drought （without watering up to 4days）. The three stresses induced oxidative damage as evidenced by an increase in lipid peroxidation. The effect varied with the stress imposed and the length of exposure. The activity of superoxide dismutase （SOD） increased in response to all stresses but was not significantly different from the controls （P 〈 0.05） when exposed to cold stress. Catalase （CAT） activity decreased in response to heat and drought stress but increased when exposed to cold conditions. Guaiacol peroxidase （POD） and glutathione reductase （GR） activities increased in response to cold and drought but decreased in response to heat stress. The activity of ascorbata peroxidase （APX） responded differently to all three stresses. Monodehydroascorbate reductase （MDHAR） activity decreased in response to heat and drought, and slightly increased in response to the cold stress but was not significantly different from the controls （P 〈 0.05）. The activity of dehydroascorbata reductase （DHAR） increased in response to all three stresses. Taken together, the co-ordinate increase of the oxygen-detoxifying enzymes might be more effective to protect crofton weed from the accumulation of oxygen radicals at low temperatures rather than at high temperatures.     

白茅对紫茎泽兰的竞争效应

外来生物的入侵可导致环境退化、生物多样性降低和食物及水资源短缺,利用本地植物或优良牧草进行替代控制是治理入侵植物的有效途径之一。采用本地禾本科植物白茅与紫茎泽兰等比例混合种植,研究了其对紫茎泽兰的竞争效应。结果表明:白茅与紫茎泽兰之间呈现很强的竞争作用,可用作紫茎泽兰的替代控制植物;白茅地上部分相对竞争力比紫茎泽兰强,其幼苗萌发早于紫茎泽兰,株高和单株平均叶面积均显著高于紫茎泽兰;二者混合种植可显著抑制紫茎泽兰的植株生长和分蘖,混合种植区紫茎泽兰的株高、单株平均叶面积和叶绿素含量分别只有其单种的49%、72%和77%;而混合种植对白茅植株生长的影响不显著,并可促进其分蘖,混合种植区的白茅分蘖数达单种区的132%。白茅的相对产量显著高于紫茎泽兰的对应指标,竞争效应参数相对产量总和1.0;随着混合种植时间的延长,两者的竞争关系将愈加显著。     

Population genetics of Ageratina adenophora using inter-simple sequence repeat (ISSR) molecular markers in China

Abstract

Understanding distribution and diversity of invasive weeds is essential for the development of efficient control measures against it. In the present study, inter-simple sequence repeat (ISSR) markers were used to assess the biogeographic relationships among populations of the invasive Crofton weed (Ageratina adenophora (Spreng.)) during 2004–2006 in China. A total of 100 ISSR primers with di-, tri-, tetra- and penta-nucleotide repeats were screened, from which 20 polymorphic and informative primers were selected. Amplification of the 20 primers generated a total of 479 polymorphic bands among the 64 weed populations, and a high level of genetic diversity (H _E = 0.1541 ± 0.0193) was detected in A. adenophora. Neighbor-joining (NJ) cluster analysis based on genetic distances among populations grouped the populations according to their geographical origin, i.e. (1) populations of southwestern Guizhou, (2) populations of Liangshan city in Sichuan, (3) populations of western Guizhou, (4) Guangxi populations plus Chongqing populations, (5) populations of southern Yunnan, and (6) populations of Yangtze River Valleys in Sichuan plus populations of western Yunnan. A significant positive correlation between geographical and genetic distance was detected by the Mantel test (r = 0.183, p = 0.0012). Based on the divergence relationships revealed by ISSR markers, it was assumed that A. adenophora mainly dispersed through wind and water in China.