The allelopathy of Flaveria bidentis (L.) Kuntze, an invasive weed species

To identify the allelopathic effect of Flaveria bidentis (L.) Kuntze (F. bidenti) on other plants, the effects of different extracts from F. bidentis on the growth of several plants were studied by bioassay. Results showed that the water extracts inhibited the growth of corn (Zea mays L.), wheat (Triticum aestivum L.), cotton (Gassypium Hirsutum L.), soybean (Glycine hispida L.), peanut (Arachi shypogaea L.), rice (Oryza sativa L.), crabgrass (Digitaria sanguinalis L.) and rigweed (Amaranthus retroflexus L.), with the most reactive indexes found in root and stem of cotton at −0.85 and −0.88, respectively, at a concentration of 0.2 g·mL⁻¹. However, the water extracts accelerated the growth of rice. In addition, the reactive indexes of the extracts of petroleum ether chloroform, ethyl acetate, acet and alcohol were higher than that of the water extracts, and that of the acet extracts was the highest. The melting point of the refined acetone extract ranged from 192.5°C to 193.5°C, and its maximum absorbing wavelength was 220 nm. This extract was found to be herbicide-active and played an inhibitory role in the growth of crabgrass and rigweed at concentrations of 1000, 500, 100 and 50 mg·L⁻¹. __________ Translated from Journal of Agricultural University of Hebei, 2007, 30(6): 63–67 [译自 : 河北农业大学学报]     

入侵植物银花苋对3种蔬菜种子萌发的化感效应

为了解外来入侵植物银花苋(Gomphrena celosioides)的潜在生态危害,采用不同器官作供体对3种作物种子萌发和幼苗生长进行化感效应测试。结果表明:总体上,花、叶水提液低浓度处理对萝卜(Raphanus sativus)、芥菜(Brassica juncea)和菜心(B.parachinensis)种子的萌发率和根长生长有抑制作用,且随着浓度提高抑制程度加大,部分达极显著水平。低浓度的花、叶水提液对作物茎(芽)长生长有一定促进作用,但随着浓度提高促进作用降低,高浓度处理则出现显著抑制。比较综合效应指数,叶水提液比花水提液的化感作用强;叶水提液对3种作物的化感作用表现为芥菜>萝卜>菜心,而花水提液则为萝卜>芥菜>菜心。因此,作为外来入侵植物,银花苋因具较强的化感效应,需加强防治。     

Factors affecting the geographical distribution of invasive species in China

Frequent international trade has accelerated alien species invasion. However, data on the distribution of invasive species after their introduction and research on the factors that determine their geographical distribution are lacking. This study analyzed the distributional trends of invasive species in China and the drivers for such trends, by identifying the effect of international trade from a dynamic analysis of 13 main invasive insect pests in three time periods – before China’s reform and opening up in 1978, from 1979 to 2001, and after China’s accession to the World Trade Organization in 2001. The results showed that the abundance of invasive species gradually decreased from south to north and from southeast coast to inland. Guangdong (442 species) and Yunnan (404 species) provinces have the highest abundance of invasive species. Among the 13 key invasive insects investigated, 3, 10 and 13 occurred chronologically in the three periods, and invaded 7, 28 and 34 provinces, respectively. Alien pests are found to invade China through Xinjiang, the Bohai Rim and the southeast. Value of imports was a strong predictor of the number of invasive species in China, and followed by temperature heterogeneity, in explaining the richness pattern of invasive animal, plants and insects, but not that of microorganisms. This study provides a scientific basis for furthering international quarantine and effective invasive species control.     

The future of language

The world's language system is undergoing rapid change because of demographic trends, new technology, and international communication. These changes will affect both written and spoken communication. English may not be the dominant language of the future, and the need to be multilingual will be enhanced. Although many languages are going extinct, new ones are emerging in cities and extended social groups.     

The bridge of language

The elements of human culture, including literature and the sciences, grow out of a basis in social concern. As they develop, their inner structures begin to emerge and those practicing them make discoveries within those structures. When tensions arise with the concerns of society a divided loyalty arises. In the past, social concerns which resisted science or censored literature were usually wrong, but there are very intense concerns today, such as environmental pollution, which appear to be bringing us to a common meeting point.     

用优雅玩转设计——关于莫娜·哈吉

我喜欢设计,喜欢用心中对室内环境的构想为我的客户创造一个美好的家。我真的热爱这个行业,永远不会对此感到厌倦。当人们走进来,我希望他们觉得家是这个世界上唯一的归属。——莫娜·哈吉     

InvasionDB: A genome and gene database of invasive alien species

Invasive alien species(IAS) are species whose introduction to areas outside of their native range cause harm to economics, biodiversity, and the environment. Understanding the genetic basis of invasiveness is critical for preventing invasion by an alien species and managing IAS with eco-friendly control methods. In addition, uncovering the genomic features of IAS is essential for accurately predicting invasiveness. However, even though increasing efforts have been devoted to sequencing the genomes of IAS, there is still not an integrated genome database for the invasive biology community. Here, we first determined a list of invasive plants and animals by mining references and databases. Then, we retrieved the genomic and gene data of these IAS, and constructed a database, Invasion DB. Invasion DB encompasses 131 IAS genomes, 76 annotated IAS assemblies, and links these data to conventional functions such as searching for gene coding sequences and Pfam, KEGG, NR annotations, BLAST server, JBrowse, and downloads services. Next, we analyzed 19 invasivenessrelated gene families which confer invasiveness in insects. To study the roles of noncoding RNA in invasiveness, we also annotated 135 494 mi RNAs, 89 294 r RNAs, and 2 671 941 t RNAs from these IAS. In summary, Invasion DB is useful for studying the invasiveness at the genomic level, and thus helps to develop novel management strategies to control IAS.     

全球林业外来有害生物研究的文献计量分析

为了掌握林业外来有害生物研究的全球状况和前沿动态,客观反映相关国家在该领域的科学能力和科学影响,采用 ISI Web of Science引文数据库,以林业外来有害生物研究的主要主题术语作为检索词,对1998—2007年之间该库收录的相关文献进行了文献计量研究。结果表明:美国、澳大利亚、新西兰、加拿大和法国是该领域的5强国家;中国在发文量前20位国家中居于第8位;国际上发表高被引论文的前5位作者的文章被引次数超过100次,而中国作者发表的文章被引次数最高为16次;在林业入侵种研究方面发文最多的25个研究机构中,美国有20个,中国没有机构入选;中国从事该领域研究的主要机构是中国科学院、香港大学、中国农业科学院和中山大学,这些机构的研究走在前列,值得同行关注。      

广东省鼎湖山国家级自然保护区外来入侵植物调查

采用线路调查与样方调查相结合的方法．对鼎湖山国家级自然保护区不同功能区内的外来入侵植物进行了野外实地调查。结果表明,实验区、缓冲区和核心区都有外来入侵植物的分布。实验区样方内共发现53种植物。其中外来入侵植物计有14种。占植物总数的26．42％．外来入侵植物胜红蓟Ageratum conyzoides和小叶冷水花只fea microphylla的优势度综合值最大。在缓冲区样方内共调查到62种杂草,其中外采入侵植物14种．占植物总数的22．58％,外来入侵植物小叶冷水花、胜红蓟和三裂蟛蜞菊Wedelia trilobata的优势度综合值最大。在核心区的样方内共调查到了24种植物,外来入侵植物有3种,占植物总数的12．50％,入侵植物数量明显低于实验区和缓冲区,优势度综合值最大的外来入侵植物是草胡椒Peperomia pellucida和胜红蓟。同时对外来植物入侵途径和对保护区的生态影响也进行了分析。本调查结果将对自然保护区生物多样性的有效保护和外来入侵植物的管理提供科学依据。表3参18     

防控船舶压载水造成的生物入侵的管理问题

船舶压载水携带大量生物到地理隔绝水域可能引起严重的生态问题,成为引入海洋外来入侵生物的主要途径之一。2004年IMO通过了《控制和管理船舶压载水和沉积物国际公约》,制定了压载水管理的国际规则。尽管该公约尚未达到生效条件,美国、澳大利亚等国家已经开始通过国内立法单方面实施船舶压载水管理。我国现有涉及船舶压载水管理的立法主要限于防止污染和卫生防疫,尚未有从防止生物入侵的角度的专门或具体的法律规定,未能实施相应的管理。建议:(1)尽快完善船舶压载水管理立法;(2)先行要求入境船舶压载水深海置换;(3)加强港口和近岸水域本地生物本底调查;(4)加强压载水管理技术研究;(5)建立管理部门多方协调机制;(6)及早准备对本国船舶的压载水管理。     

我国外来生物入侵现状及防范对策

分析我国外来生物入侵所造成的危害,主要是对农林业、生态环境、生物多样性、人类健康和国家安全造成破坏和威胁;外来生物入侵的途径主要有生物自然扩散传播、人为引种传入、随国际贸易往来传入等;目前我国的防范工作主要有3个方面,即检验检疫部门在口岸一线检疫防控,农林部门引种审批与病虫害防治,环保部门生态环境治理等,各部门均取得了成效,但也存在薄弱环节和问题。在分析形势、现状和问题的基础上,提出5点对策建议:一是落实科学发展观,提高全社会对防范工作重要性的认识;二是制定和完善相关法规,保证防范工作均有法可依;三是理顺关系明确职责,建立多部门齐抓共管机制;四是强化口岸检疫措施,筑牢第一道防线;五是建立健全外来生物监控网络,保障防范工作及时有效。     

进境卡特兰种苗有害生物风险分析

依据国际植物检疫实施标准，对我国进境卡特兰可能携带的有害生物进行风险评估，确定了8种检疫性有害生物，5种潜在的非检疫性有害生物，并提出相应的风险管理措施。     

3种茄科入侵植物在我国的潜在地理分布及气候适生性分析

[目的]探究喀西茄(Solanum khasianum)、牛茄子(Solanum capsicoides)和曼陀罗(Datura stramonium)3种茄科入侵植物在我国的分布格局及其主要气候环境影响因子,为3种茄科入侵植物的监测、预警和防控提供科学依据.[方法]获取3种茄科入侵植物在我国的已知分布点,结合生物环境空间数据,利用最大熵模型(MaxEnt)预测其在我国的3 km×3 km分辨率适生性空间分布概率,并分析3种茄科入侵植物地理分布的空间重叠特征及影响其空间分布的主要气候环境因子.[结果]喀西茄、牛茄子和曼陀罗3种茄科入侵植物在我国的入侵分布区广泛,分别占国土面积的20.09%、25.69%和62.49%,但地理分布存在明显空间分异和局部空间重叠.其中,曼陀罗除青藏高原外各地区均有其适生区,而喀西茄和牛茄子主要分布于亚热带地区;喀西茄的适生区主要集中在西南云贵高原,是其入侵的重灾区,尤其是云南、广西、贵州及其周边的省份;牛茄子分布范围较喀西茄广,主要分布在热带和亚热带地区,适生性自南向北逐渐减弱.[结论]我国西南地区是喀西茄和牛茄子入侵的集中适生区和重灾区.3种茄科植物在云贵高原和横断山区均有气候适宜重叠区,是入侵茄科植物的未来重点防疫区.     

三种木质藤本植物光合特性比较研究

\t\t\t\t\t目的\t\t\t\t\t对25个茶树品种春、夏、秋季的光合性能进行评价。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t采用Li-6400光合系统测定不同茶树春、夏、秋季新梢叶片的光合参数并予以统计分析。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t因子分析提取的2个因子可以概括81.16%的光合参数信息,因子1主要受净光合速率(P_n)、气孔导度(G_s)、胞间CO₂浓度(C_i)及羧化率(CE)的影响,因子2主要受水分利用率(WUE)和蒸腾速率(T_r)的影响;春季,铁观音、菊花春的光合因子综合得分较高;夏季,浙农113和中茶302得分较高;秋季,浙农113和巴渝特早得分较高。系统聚类将所有材料分为2类,其中大部分茶树夏季的叶片为一类,具有较高的P_n和WUE;春、秋季的所有茶树叶片及黔湄502等6个茶树品种的夏季叶片为一类,具有较高的P_n、G_s、C_i和T_r,但WUE较低。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t制定栽培管理措施时应因时因品种制宜。\t\t\t\t     

银合欢叶片水提液对3种蔬菜种子萌发的化感效应

研究外来入侵植物银合欢(Leucaena leucocephala)叶片的化感作用,为揭示潜在的生态危害提供参考.配置不同浓度的银合欢叶水提液处理3种十字花科蔬菜种子,按生物测定方法及公式计算其化感指数和综合效应.结果显示,随着银合欢叶水提液浓度的增加,对芥菜(Brassicajuncea)、菜心(B.parachinensis)和白菜(B.pekinensis)种子萌发和根长生长的抑制作用增强,且抑制作用大小整体表现为芥菜＞菜心＞白菜;不同浓度叶水提液对不同受体植物幼苗茎长生长的影响情况较复杂.综合效应指数表明,银合欢叶对3种十字花科蔬菜作物种子萌发均有较明显的化感作用.结果提示,银合欢作为外来入侵植物,因具较强的化感效应,需加强防治.