WorldWideScience

Sample records for allelopathy

  1. Phenolics and Plant Allelopathy

    OpenAIRE

    De-An Jiang; Cun-De Pan; Xiao Ruan; Qiang Wang; Zhao-Hui Li

    2010-01-01

    Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical ...

  2. Phenolics and Plant Allelopathy

    Directory of Open Access Journals (Sweden)

    De-An Jiang

    2010-12-01

    Full Text Available Phenolic compounds arise from the shikimic and acetic acid (polyketide metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.

  3. Current Research Status of Allelopathy

    Directory of Open Access Journals (Sweden)

    AHMAD JUNAEDI

    2006-06-01

    Full Text Available The term of allelopathy refers to chemical interactions (inhibitory or stimulatory between plants, between plants and microorganisms, and between microorganisms. The wealth of information on the processes, procedures, and practices of allelopathy has contributed to understanding this field of science. Recently, researches of allelopathy have been conducted in laboratory, greenhouse, and field with multifaceted standpoint in some concerning area: (i allelochemicals identifications and screening test; (ii ecological and physiological aspects of allelopathy; (iii genetic studies and the possibilities of using plant breeding or genetic manipulation to enhance allelopathic varieties; (iv the use of allelopathic potential in the biological control, including as natural pesticide, of weeds and plant diseases as eco-friendly approach for sustainable agriculture scheme.

  4. Allelopathy of plants in space

    Science.gov (United States)

    Tomita-Yokotani, K.; Baba, K.; Fujii, Y.; Hashimoto, H.; Nakamura, T.; Yamashita, M.

    Allelopathy is a chemical way of interaction among many organisms living together on the earth, and forming ecological systems as the member of the biosphere. Biosynthesis of allelochemicals, their release, transport and sensing mechanism at the recipient organisms, which is associated with allelopathy, are under the influence of gravity in many aspects. Such gravitational action on the allelopathy could be ranged from perturbation on biochemical networks in the cells to macroscopic transportation phenomena around the organisms. If gravity is an environmental factor that governs those processes, allelopathy at the absence of gravity on space craft, or under the different magnitude of gravity on the outer planets might differ from allelopathy on the ground. Another important factor in allelopathy in space application is physical closure of living environment, and lack of natural process to decompose allelopathic chemicals or the sink among material circulation in the biosphere. Many organisms and ecological system may behave differently in spacecrafts or on outer planets, based on the modified inter-organisms and -species interactions associated with alleopahty. In order to examine allelopathy under exotic gravity and closed environment, we imposed pseudo-microgravity and physical closure on a plant-plant allelopathy system. Two plant species were co-cultured in a closed vessel, and gravity vector was randomized by the 3D-clinorotation. Velvet bean (Mucuna pruriens L.) is known to induce strong allelopathic action on many plant species. Velvet bean and lettuce was chosen as the pair. Growth of lettuce seedlings, co-cultured with velvet bean, was analyzed under the 3D-clinorotation, and compared it with growth of the ground control group. The degree of allelopathic suppression on the lettuce root growth was less on the 3D-clinorotation. L-DOPA (L-3,4-dihydroxy-phennylalanine), released from root is the major substance responsible to the allelopathy of velvet bean

  5. Genetic analysis of rice allelopathy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A double haploid population derived from anther culture of ZYQ8/JX17, a typical indica and japonica hybrid, was used in this study. The inhibited effect of water-soluble extract of 123 DH pure lines leaves on the lettuce roots growth was investigated, and the QTLs analysis of rice allelopathy was carried out. Totally, four QTLs related to rice allelopathy were detected, and they were on chromosomes 3, 9, 10 and 12, respectively. The LOD scores were 3.40, 2.68. 2.75 and 3.08, respectively. Among them, additive effects of the QTLs on chromosomes 3 and 10 were 1.65 and 1.43, on chromosomes 9 and 12 were ?1.44 and ?1.58, respectively. Allelopathy characteristics of another three common rice varieties were also studied.

  6. Research advances in allelopathy of Quercus L.

    Institute of Scientific and Technical Information of China (English)

    Li Guang-de; Jia Li-ming; Li Xiao-wen

    2007-01-01

    The term allelopathy refers to biochemical interaction between all types of plants including microorganisms through production of chemical compounds that escape into the environment and exist widely in Quercus L. The development of investigations into types of allelochemicals,their compounding and spreading pathways,as well as expression of allelopathy in Quercus L. are reviewed in this paper:We have closely and systematically emphasized the functional mechanisms of allelopathy in forest plants for our next research project on allelopathy in Quercus L.

  7. Allelopathy problems at Nardus stricta

    Directory of Open Access Journals (Sweden)

    Viorica TARAU

    1967-08-01

    Full Text Available Um einige Fragen des Allelopathie Problemes bei Nardus stricta Grunland zu erklaren, haben die Verfasser der vorliegenden Arbeit die Wirkung einiger Bodenlosungen, die dem Boden unter der gut umgrenzten Vegetation der Maulwurfshugel einer Nardus strictae collinum - Assoziation entnommen wurden, auf die Keimung der Samen von Trifolium pretense, Lotus corniculatus, Lolium perene und Phleum pratense verfolgt. Eine starker hemmende Wirkung auf die Keimung aller untersuchten Arten hatten die Losungen aus dem Boden unter Festuca rubra + Agrostis tenuis, Festuca rubra + Polytrichum juniperinum. Nardus stricta hat die Keimung von Trifolium pretense stark gehemmt, wahrend Holcus lanatus die Keimung samtlicher studierten Arten stimuliert hat.

  8. An Aromatic Adventure with Allelopathy: Using Garlic to Study Allelopathy in the Classroom

    Science.gov (United States)

    Shimabukuro, Mary A.; Haberman, Vickie

    2006-01-01

    In this paper, the authors explore the potential of garlic ("Allium sativum L.") to illustrate the concept of allelopathy and demonstrate the biological activity of plant volatiles. This article describes several classroom experiments involving garlic that can be used as a method of introducing students of various ages to the following important…

  9. Allelopathy, seed germination, weed control and bioassay methods

    OpenAIRE

    Dias, L.S.; Pereira, I.P.; A. S. Dias

    2016-01-01

    Even before its formal establishment as a scientific discipline, allelopathy has been intertwined with agriculture and the potential of allelopathy for weed control has been a permanent matter of interest. Therefore we investigate the importance of seeds and of permanent soil seed banks as a means for propagation of weed species as well as strategies for long-term weed control. Depleting seed banks is critical and encouraging weed seed germination prior to sowing crops is one of the most prom...

  10. Allelopathy in crop/weed interactions--an update.

    Science.gov (United States)

    Belz, Regina G

    2007-04-01

    Since varietal differences in allelopathy of crops against weeds were discovered in the 1970s, much research has documented the potential that allelopathic crops offer for integrated weed management with substantially reduced herbicide rates. Research groups worldwide have identified several crop species possessing potent allelopathic interference mediated by root exudation of allelochemicals. Rice, wheat, barley and sorghum have attracted most attention. Past research focused on germplasm screening for elite allelopathic cultivars and the identification of the allelochemicals involved. Based on this, traditional breeding efforts were initiated in rice and wheat to breed agronomically acceptable, weed-suppressive cultivars with improved allelopathic interference. Promising suppressive crosses are under investigation. Molecular approaches have elucidated the genetics of allelopathy by QTL mapping which associated the trait in rice and wheat with several chromosomes and suggested the involvement of several allelochemicals. Potentially important compounds that are constitutively secreted from roots have been identified in all crop species under investigation. Biosynthesis and exudation of these metabolites follow a distinct temporal pattern and can be induced by biotic and abiotic factors. The current state of knowledge suggests that allelopathy involves fluctuating mixtures of allelochemicals and their metabolites as regulated by genotype and developmental stage of the producing plant, environment, cultivation and signalling effects, as well as the chemical or microbial turnover of compounds in the rhizosphere. Functional genomics is being applied to identify genes involved in biosynthesis of several identified allelochemicals, providing the potential to improve allelopathy by molecular breeding. The dynamics of crop allelopathy, inducible processes and plant signalling is gaining growing attention; however, future research should also consider allelochemical release

  11. Weeds Cause Losses in Field Crops through Allelopathy

    OpenAIRE

    Tasawer ABBAS; Tahira TABASSUM

    2016-01-01

    A large number of weeds are known to be associated with crops and causing economic losses. Weeds interfere with crops through competition and allelopathy. They produce secondary metabolites known as allelochemicals, which belong to numerous chemical classes such as phenolics, alkaloids, fatty acids, indoles, terpens etc. However, phenolics are the predominant class of allelochemicals. The allelochemicals release from weed plants takes place through leaf leachates, decomposition of plant resid...

  12. Allelopathy: Current Status of Research and the Future of the Discipline: A Commentary

    Science.gov (United States)

    The study of allelopathy as a discipline has a long and varied history. Since Hans Molisch coined the term before World War II, allelopathy research has grown from a trickle of papers before 1970 to a burgeoning subdiscipline of chemical ecology represented by hundreds of papers each year. Yet, al...

  13. Toxin-allelopathy among phytoplankton species prevents competitive exclusion

    OpenAIRE

    Roy, Shovonlal; Chattopadhyay, Joydev

    2006-01-01

    Toxic or allelopathic compounds liberated by toxin-producing phytoplankton (TPP) acts as a strong mediator in plankton dynamics. On an analysis of a set of phytoplankton biomass-data that have been collected by our group in the North-West part of the Bay of Bengal, and by analysis of a three-component mathematical model under a constant as well as a stochastic environment, we explore the role of toxin-allelopathy in determining the dynamic behaviour of the competing-phytoplankton species. The...

  14. Models for the directed evolution of bacterial allelopathy: bacteriophage lysins

    Directory of Open Access Journals (Sweden)

    James J. Bull

    2015-04-01

    Full Text Available Microbes produce a variety of compounds that are used to kill or suppress other species. Traditional antibiotics have their origins in these natural products, as do many types of compounds being pursued today in the quest for new antibacterial drugs. When a potential toxin can be encoded by and exported from a species that is not harmed, the opportunity exists to use directed evolution to improve the toxin’s ability to kill other species—allelopathy. In contrast to the typical application of directed evolution, this case requires the co-culture of at least two species or strains, a host that is unharmed by the toxin plus the intended target of the toxin. We develop mathematical and computational models of this directed evolution process. Two contexts are considered, one with the toxin encoded on a plasmid and the other with the toxin encoded in a phage. The plasmid system appears to be more promising than the phage system. Crucial to both designs is the ability to co-culture two species/strains (host and target such that the host is greatly outgrown by the target species except when the target species is killed. The results suggest that, if these initial conditions can be satisfied, directed evolution is feasible for the plasmid-based system. Screening with a plasmid-based system may also enable rapid improvement of a toxin.

  15. [Allelopathy of decomposing pepper stalk on pepper growth].

    Science.gov (United States)

    Hou, Yongxia; Zhou, Baoli; Wu, Xiaoling; Fu, Yawen; Wang, Yueying

    2006-04-01

    With decomposing pepper stalk as test material, this paper studied its allelopathy on the growth of pepper plants. The results showed that after 60 days of decomposition, the decomposed pepper stalk could decrease the plant height, stem diameter, dry weights of above-and underground biomass, leaf area, and chlorophyll content of pepper plants by 0.0374 - 0.0646, 0.0020 - 0.0097, 0.0050 - 0.0355 and 0.0916 - 0.3584, 0.0016 - 0.0251, and 0.0043 - 0.0242 respectively. These inhibitory effects were enhanced after 120 days of decomposition, but the difference with CK was not significant. The root vigor and its SOD, POD and CAT activities of pepper plants were decreased, while the MDA content and relative conductivity were increased with the increasing concentration of decomposed pepper stalk and with the prolong of treating time. The allelopathic effects of decomposed pepper stalk on the physiological indices of pepper root activity ranged from 0.0163 to 0.6507, which was significantly higher than that of plant growth index.

  16. Weeds Cause Losses in Field Crops through Allelopathy

    Directory of Open Access Journals (Sweden)

    Tasawer ABBAS

    2016-03-01

    Full Text Available A large number of weeds are known to be associated with crops and causing economic losses. Weeds interfere with crops through competition and allelopathy. They produce secondary metabolites known as allelochemicals, which belong to numerous chemical classes such as phenolics, alkaloids, fatty acids, indoles, terpens etc. However, phenolics are the predominant class of allelochemicals. The allelochemicals release from weed plants takes place through leaf leachates, decomposition of plant residues, volatilization and root exudates. Weeds leave huge quantities of their residues in field and affect the associated, as well as succeeding crops, in various cropping systems. Liberation of allelochemicals from weeds affects the germination, stand establishment, growth, yield and physiology of crop plants. They cause substantial reduction in germination and growth of the crop plants by altering various physiological processes such as enzyme activity, protein synthesis, photosynthesis, respiration, cell division and enlargement, which ultimately leads to a significant reduction in crop yield. In crux, allelopathic weeds represent a potential threat for crop plants and cause economic losses.

  17. [Allelopathy effects of ferulic acid and coumarin on Microcystis aeruginosa].

    Science.gov (United States)

    Guo, Ya-Li; Fu, Hai-Yan; Huang, Guo-He; Gao, Pan-Feng; Chai, Tian; Yan, Bin; Liao, Huan

    2013-04-01

    The inhibitory effects and allelopathy mechanism of ferulic acid and coumarin on Microcystis aeruginosa were investigated by measuring the D680 value, the content of chlorophyll-a, the electrical conductivity (EC) and superoxide anion radical O*- value. Ferulic acid and coumarin had allelopathic effects on the growth of M. aeruginosa and promoted the physiological metabolism at low concentrations while inhibited the metabolism at high concentrations. Obvious inhibitory effects were observed when the concentration of ferulic acid or coumarin was over 100 mg x L(-1). The average inhibitory rates reached 80.3% and 58.0% after six days when the concentration of ferulic acid or coumarin was 200 mg x L(-1). The content of chlorophyll-a was decreased while the EC value and O2*- concentration were promoted by higher concentrations of ferulic acid or coumarin, suggesting that the growth of algae was inhibited probably by the damage of cell membrane, increase in the content of O2*- and decrease in the content of chlorophyll-a. In addition, seed germination test elucidated that Ferulic acid was safer than Coumarin.

  18. Interaction between the macrophyte Stratiotes aloides and filamentous algae: does it indicate allelopathy?

    NARCIS (Netherlands)

    Mulderij, G.; Mau, B.; De Senerpont Domis, L.N.; Smolders, A.J.P.; Van Donk, E.

    2009-01-01

    The aquatic macrophyte Stratiotes aloides Linnaeus, which has recently received attention in studies on allelopathy, has been shown to suppress phytoplankton growth. In the Netherlands, S. aloides often co-occurs with floating filamentous algae. However, filamentous algae are generally absent in clo

  19. Pattern formation for a model of plankton allelopathy with cross-diffusion

    DEFF Research Database (Denmark)

    Tian, C.R.; Zhang, Lai; Lin, Z.G.

    2011-01-01

    In this paper, we develop a theoretical framework for investigating spatial patterns on plankton allelopathy with cross-diffusion. We show that under some conditions the cross-diffusion is able to induce the Turing instability, which is further confirmed by the numerical simulations. Moreover...

  20. Algal-bloom control by allelopathy of aquatic macrophytes——A review

    Institute of Scientific and Technical Information of China (English)

    Hongying HU; Yu HONG

    2008-01-01

    Algal-bloom control is an important issue for water environment protection as it induces several nega-tive impacts on the lives of aquatic organisms, aquacul-ture, landscaping, and human health. The development of an environment-friendly, cost-effective, and convenient alternative for controlling algal bloom has gained much concern. Using the allelopathy of aquatic macrophytes as a novel and safe method for algal-bloom control is a promising alternative. This paper reviews the develop-ment and potential application about allelopathy of aquatic plants on algae, including the allelopathic research history, the potential research problems, the research methodology, and the reported aquatic macro-phytes and their inhibitory allelochemicals. Potential modes of inhibition action of allelochemicals on algae, possible ways for application, and future development directions of research on algal-bloom control by aquatic macrophytes were also presented.

  1. Analysis on Dynamic Heterosis for Allelopathy in Rice Under Different Environment Conditions

    Institute of Scientific and Technical Information of China (English)

    LIN Wen-xiong; DONG Zhang-hang; CHEN Xiang-xu; HE Hua-qin; SHEN Li-hua; GUO Yu-chun; LIANG Yi-yuan; CHEN Fang-yu; LIANG Kang-jing

    2003-01-01

    In this study, 5 parental rice varieties with different allelopathic potentials were employed indiallel cross [P(P+ 1)/2] to get a set of genetic materials including parental lines and two generations of F1 s.The dynamic heterosis for allelopathy in rice under different environmental conditions, was analyzed by usingadditive-dominant developmental genetic model. The results indicated that heterosis in both F1 and F2 showedinhibitory effects on shoot and root length of receiver plant (Lactuca sativa L. ). Heterosis over mid-parentbased on population mean(HMP) in F2 was lower than that in differental environmental conditions, showing1/2 HMP in F1. The heterosis in rice allelopathy was much higher under the field environmental conditionswith lower temperature and weaker sunlight than that under favorable environment, implying that the allel-opthic potential could be increased by stress environment. This finding interpreted the genetic reason thatplant could produce more allelochemicals under unfavorable environment.

  2. Separation of allelopathy from resource competition using rice/barnyardgrass mixed-cultures.

    Directory of Open Access Journals (Sweden)

    Hai Bin He

    Full Text Available Plant-plant interference is the combined effect of allelopathy, resource competition, and many other factors. Separating allelopathy from resource competition is almost impossible in natural systems but it is important to evaluate the relative contribution of each of the two mechanisms on plant interference. Research on allelopathy in natural and cultivated plant communities has been hindered in the absence of a reliable method that can separate allelopathic effect from resource competition. In this paper, the interactions between allelopathic rice accession PI312777, non-allelopathic rice accession Lemont and barnyardgrass were explored respectively by using a target (rice-neighbor (barnyardgrass mixed-culture in hydroponic system. The relative competitive intensity (RCI, the relative neighbor effect (RNE and the competitive ratio (CR were used to quantify the intensity of competition between each of the two different potentially allelopathic rice accessions and barnyardgrass. Use of hydroponic culture system enabled us to exclude any uncontrolled factors that might operate in the soil and we were able to separate allelopathy from resource competition between each rice accession and barnyardgrass. The RCI and RNE values showed that the plant-plant interaction was positive (facilitation for PI312777 but that was negative (competition for Lemont and barnyardgrass in rice/barnyardgrass mixed-cultures. The CR values showed that one PI312777 plant was more competitive than 2 barnyardgrass plants. The allelopathic effects of PI312777 were much more intense than the resource competition in rice/barnyardgrass mixed cultures. The reverse was true for Lemont. These results demonstrate that the allelopathic effect of PI312777 was predominant in rice/barnyardgrass mixed-cultures. The most significant result of our study is the discovery of an experimental design, target-neighbor mixed-culture in combination with competition indices, can successfully

  3. Status Quo and Future Development Trend of Rice Allelopathy Researches%水稻化感作用研究现状及未来发展方向

    Institute of Scientific and Technical Information of China (English)

    黄新玲; 张振海

    2015-01-01

    以国内外水稻化感作用的研究现状为基础,从化感物质的作用原理、优势化感品系的筛选和评价以及化感物质的获取等多角度对水稻化感的作用进行阐述,同时对水稻化感作用未来发展方向提出有关建议。%According to the characteristics of rice allelopathy, people have carried out a large number of relevant tests and probes. This paper summarized the status quo of rice allelopathy researches and analyses. Rice allelopathy activities were elaborated from such perspectives as the allelopathy mechanisms of allelopathy exodates, the screening and evaluation of advantageous allelopathy strains as well as the acquisition of allelopathy exudates. Finally, the future development trends of rice allelopathy activities were explored.

  4. Research Advance on Allelopathy of Panax notoginseng%三七化感作用研究进展

    Institute of Scientific and Technical Information of China (English)

    李瑞博; 寻路路; 赵宏光; 崔秀明

    2012-01-01

    Allelopathy is one effective way to solve the continuous cropping obstacles ofpanax notoginseng. The development and progress of studies on the allelopathy ofpanax notoginseng in recent years and the allelopathy effect are reviewed from aspects of collecting and extracting methods,allelochemicals types currently known to exist and allelopathic extracts effects on panax notoginseng. The research progresses of allelopathy in panax notoginseng and the existing problems are discussed which will provide theoretical reference value for researchers working on allelopathy of panax notoginseng.%化感作用研究是解决三七连作障碍问题的有效途径之一.文章综述了近年来在三七化感方面的研究成果,从化感物质的收集提取方法到目前已知存在的化感物质种类、化感提取物对三七存在的化感效应.探讨了三七化感研究的发展现状及存在的不足,为进一步开展三七化感研究提供参考.

  5. Allelopathy and Its Ecological Significance%植物化感作用及其生态学意义

    Institute of Scientific and Technical Information of China (English)

    席蓉; 郝建锋

    2011-01-01

    The paper introduces the concept of plant allelopathy,reviews the varieties, release path, mechanism and influencing factors of allelochemicals, summarizes the application of allelopathy in agriculture and forestry ecosystem, and at last predicts the development prospect of allelopathy.%介绍了植物化感作用的概念,综述了化感物质的种类和释放途径,分析了化感物质的作用机理及影响化感物质作用的因素,总结了植物化感作用在农林业、森林生态系统中的应用,并对化感作用的发展前景进行了展望.

  6. Research Progress on Watermelon Allelopathy%西瓜化感作用研究进展

    Institute of Scientific and Technical Information of China (English)

    张小红; 赵依杰

    2013-01-01

    西瓜连作引起化感物质积累,导致产量下降,研究西瓜化感作用对揭示西瓜连作障碍机理、克服西瓜连作障碍具有重要的意义。本文对西瓜化感作用的研究进展进行了综述,包括西瓜化感现象的研究现状、化感物质及其释放途径、化感物质的作用特点、以及化感作用在西瓜生产实践中的应用,并提出西瓜化感作用未来的研究方向,旨在为制定增强西瓜抗逆性能和提高西瓜产量、品质的科学途径提供一定理论参考。%The continuous cropping of watermelon〔Citrullus lanatus(Thunb.)Matsum. et Nakai〕leads to the accumulation of allelochemicals,and causes the decrease of yield.It is of important significance to reveal the obstacle mechanism of allelopathic on watermelon continuous cropping,and overcome this obstacle.The paper reviewed the research progress on watermelon alle-lopathy,including the current research status on watermelon allelopathy,the allelochemicals and their releasing way,and the function characteristics of allelochemicals,and allelopathy application in pro-duction.The paper also prospected the future research directions on watermelon allelopathy,aiming at providing theoratical references for developing a scientific way to enhance watermelon resistance,and improving the yield and quality of watermelon.

  7. Dynamic Behaviors of a General Discrete Nonautonomous System of Plankton Allelopathy with Delays

    Directory of Open Access Journals (Sweden)

    Yaoping Chen

    2008-01-01

    Full Text Available We study the dynamic behaviors of a general discrete nonautonomous system of plankton allelopathy with delays. We first show that under some suitable assumption, the system is permanent. Next, by constructing a suitable Lyapunov functional, we obtain a set of sufficient conditions which guarantee the global attractivity of the two species. After that, by constructing an extinction-type Lyapunov functional, we show that under some suitable assumptions, one species will be driven to extinction. Finally, two examples together with their numerical simulations show the feasibility of the main results.

  8. A Study of Allelopathy of Some Shade Trees to Coffea arabicaL. Seedlings

    Directory of Open Access Journals (Sweden)

    Adi Prawoto

    2006-05-01

    Full Text Available Because of social economic judgment, many coffee planters nowadays grow Cassia spectabilisand in the certain regions used Cinnamomum burmani, Macadamia integrifolia, Tectona grandisand Cassia siameaas shade trees or intercrops. Before being used in large scale, allelopathy study is appropriate to be done because this effect is much more difficult to be overcome than competiton as growing factor. Research on allelopathy of those species had been conducted in glasshouse of Indonesian Coffee and Cocoa Research Institute using Salisbury & Ross method. Leachate of Cassia spectabilis Cinnamomum burmani, Macadamia integrifolia, Tectona grandisand Cassia siamea, pure media (without plant and control (well water were used as treatments. Planting material of Cinnamomum burmani, Macadamia integrifolia, Tectona grandisand Cassia siameawere as seedlings of one year old, whereas C. spectabiliswas 3 months old. Those materials were planted in polybags 20 cm x 30 cm and replicated five times. The media was a mixture of top soil, manure and sand 1 : 1 : 1 (v/v. After those species were maintained for one months and Arabica seedlings for three month old, watering of coffee seedlings then using leachate from shade trees media. Every two days, each seedling was applied with 200 ml. Control was applied with well water. Pure media was used to study the effect of nutrient supply contained in the leachate. The experiment was stopped at seven month old of the coffee seedlings. The result showed that C. spectabilisreleased chemicals which showed allelopathic effect to Arabica coffee, their growth was inhibited 10% to control. The growth decreament from Cassia siameaand D. zibethinustreatment mainly caused by lower mineral content in the leachate and indicated by weak allelopathic. On the other hand M. integrifoliaand C. burmanidid not show allelopathic to Arabica coffee. Thus, based on allelopathy aspect, it can be included that C. spectabilisand C. siamea were not

  9. Research Progress of Plant Allelopathy%植物化感作用研究进展

    Institute of Scientific and Technical Information of China (English)

    姚伶; 何开跃; 郭丽君; 郑纪伟

    2012-01-01

    Allelopathy universally exist in nature, involving botany, chemistry, ecology, physiology, microbiology and so on, which has significance on promoting agriculture sustainable development and eco-environment protection. At presenl there are many researches about plant allelopathy and most of the focus are harmful aspects. The species of allelochemical, action mode, mechanism, release ways and collection methods were reviewed, so as to provide reference value for the production practice.%化感作用普遍存在于自然界中,涉及植物学、化学、生态学、生理学和微生物学等学科,对促进农业可持续发展和生态环境保护有着十分重要的意义.目前,有关植物化感作用的研究报道较多,且大多偏重于植物化感作用的有害方面.该研究综述了化感物质的种类、作用方式、作用机制和化感物质的释放途径以及收集方法,以期为生产实践提供参考价值.

  10. The Impact of Competition and Allelopathy on the Trade-Off between Plant Defense and Growth in Two Contrasting Tree Species.

    Science.gov (United States)

    Fernandez, Catherine; Monnier, Yogan; Santonja, Mathieu; Gallet, Christiane; Weston, Leslie A; Prévosto, Bernard; Saunier, Amélie; Baldy, Virginie; Bousquet-Mélou, Anne

    2016-01-01

    In contrast to plant-animal interactions, the conceptual framework regarding the impact of secondary metabolites in mediating plant-plant interference is currently less well defined. Here, we address hypotheses about the role of chemically-mediated plant-plant interference (i.e., allelopathy) as a driver of Mediterranean forest dynamics. Growth and defense abilities of a pioneer (Pinus halepensis) and a late-successional (Quercus pubescens) Mediterranean forest species were evaluated under three different plant interference conditions: (i) allelopathy simulated by application of aqueous needle extracts of Pinus, (ii) resource competition created by the physical presence of a neighboring species (Pinus or Quercus), and (iii) a combination of both allelopathy and competition. After 24 months of experimentation in simulated field conditions, Quercus was more affected by plant interference treatments than was Pinus, and a hierarchical response to biotic interference (allelopathy < competition < allelopathy + competition) was observed in terms of relative impact on growth and plant defense. Both species modulated their respective metabolic profiles according to plant interference treatment and thus their inherent chemical defense status, resulting in a physiological trade-off between plant growth and production of defense metabolites. For Quercus, an increase in secondary metabolite production and a decrease in plant growth were observed in all treatments. In contrast, this trade-off in Pinus was only observed in competition and allelopathy + competition treatments. Although Pinus and Quercus expressed differential responses when subjected to a single interference condition, either allelopathy or competition, species responses were similar or positively correlated when strong interference conditions (allelopathy + competition) were imposed. PMID:27200062

  11. The Impact of Competition and Allelopathy on the Trade-Off between Plant Defense and Growth in Two Contrasting Tree Species

    Science.gov (United States)

    Fernandez, Catherine; Monnier, Yogan; Santonja, Mathieu; Gallet, Christiane; Weston, Leslie A.; Prévosto, Bernard; Saunier, Amélie; Baldy, Virginie; Bousquet-Mélou, Anne

    2016-01-01

    In contrast to plant-animal interactions, the conceptual framework regarding the impact of secondary metabolites in mediating plant-plant interference is currently less well defined. Here, we address hypotheses about the role of chemically-mediated plant-plant interference (i.e., allelopathy) as a driver of Mediterranean forest dynamics. Growth and defense abilities of a pioneer (Pinus halepensis) and a late-successional (Quercus pubescens) Mediterranean forest species were evaluated under three different plant interference conditions: (i) allelopathy simulated by application of aqueous needle extracts of Pinus, (ii) resource competition created by the physical presence of a neighboring species (Pinus or Quercus), and (iii) a combination of both allelopathy and competition. After 24 months of experimentation in simulated field conditions, Quercus was more affected by plant interference treatments than was Pinus, and a hierarchical response to biotic interference (allelopathy < competition < allelopathy + competition) was observed in terms of relative impact on growth and plant defense. Both species modulated their respective metabolic profiles according to plant interference treatment and thus their inherent chemical defense status, resulting in a physiological trade-off between plant growth and production of defense metabolites. For Quercus, an increase in secondary metabolite production and a decrease in plant growth were observed in all treatments. In contrast, this trade-off in Pinus was only observed in competition and allelopathy + competition treatments. Although Pinus and Quercus expressed differential responses when subjected to a single interference condition, either allelopathy or competition, species responses were similar or positively correlated when strong interference conditions (allelopathy + competition) were imposed. PMID:27200062

  12. 东北百里香化感作用%Allelopathy of Thymus mandschuricus

    Institute of Scientific and Technical Information of China (English)

    王玲; 马喜娟; 张秀珍

    2012-01-01

    An experiment was conducted to study the allelopathy of Thymus mandschurricus Ronn. on Jive receptor plants, namely Pinus sylvestris var. mongolica, Larix gmelini, Betula platyphylla, Tagetes erecla and Petunia hybrid by the method of biological test. Results showed that stem-leaf and root extracts of T. mandschuricus had some inhibitory effects on seed germination of B. platyphylla and P. hyhrida, and the inhibitory effects weakened with decreasing extract concentration. Lower concentration of extract had a stimulative effect on seed germination of P. sylvestris var. mongolica to a certain degree. Stem-leaf and root extracts of T. mandschuricus had no harmful effect on the seedling growth of T. erecla and P. hybrida. Extract with a volume ratio of 1 : 1 had certain inhibitory effect on seeding growth of P. sylvestris var. mongolica and L gmelini. The allelopathy effect of stem-leaf extract was stronger than that of root extract. Root length of the receptor plants received a stronger allelopathy effect than seedling height.%通过生物测定法研究了东北百里香茎叶和根水浸液对樟子松、兴安落叶松、白桦、万寿菊、矮牵牛的种子萌发及幼苗生长的化感作用.结果表明,东北百里香茎叶和根水浸液对白桦、矮牵牛的种子萌发有一定抑制作用,抑制效应随水浸液母液与水的体积比降低而减弱;母液与水的体积比低的水浸液对樟子松的种子萌发有一定促进作用.东北百里香茎叶和根水浸液对万寿菊和矮牵牛幼苗生长无明显不良影响,V(母液)∶V(水)=1∶1的水浸液对樟子松、兴安落叶松的幼苗生长有一定抑制作用.东北百里香茎叶水浸液对受体植物的化感作用强于根水浸液.受体植物幼苗的根长受到的化感作用强于苗高.

  13. Taraxacum officinale pollen depresses seed set of montane wildflowers through pollen allelopathy

    Directory of Open Access Journals (Sweden)

    Deirdre Loughnan

    2014-08-01

    Full Text Available Plant species that share pollinators can suffer from interspecific pollen deposition. Male reproductive success is inevitably reduced by the loss of pollen to flowers of another species. Female reproductive success can be affected by reduced stigmatic area or, more strongly, through allelopathic effects by which the admixture of some foreign pollen reduces seed or fruit set. We tested for allelopathic effects of Taraxacum officinale (Asteracaeae pollen on the seed set of montane wildflowers Erythronium grandiflorum (Liliaceae and Erysimum capitatum (Brassicaceae, by hand-pollinating plants with pollen mixtures. Taraxacum is a common invasive species, which produces allelopathic chemicals in its root and vegetative tissue, making it a likely candidate for pollen allelopathy. Flowers of both species produced fewer well-developed seeds when pollinated with pollen mixtures containing Taraxacum pollen. The pollen-allelopathic potential of weedy dandelion may add to its ability to disrupt communities that it invades.

  14. The stationary distribution and ergodicity of a stochastic phytoplankton allelopathy model under regime switching

    Science.gov (United States)

    Zhao, Yu; Yuan, Sanling; Zhang, Tonghua

    2016-08-01

    The effect of toxin-producing phytoplankton and environmental stochasticity are interesting problems in marine plankton ecology. In this paper, we develop and analyze a stochastic phytoplankton allelopathy model, which takes both white and colored noises into account. We first prove the existence of the global positive solution of the model. And then by using the stochastic Lyapunov functions, we investigate the positive recurrence and ergodic property of the model, which implies the existence of a stationary distribution of the solution. Moreover, we obtain the mean and variance of the stationary distribution. Our results show that both the two kinds of environmental noises and toxic substances have great impacts on the evolution of the phytoplankton populations. Finally, numerical simulations are carried out to illustrate our theoretical results.

  15. Allelopathy of rice: effect of rice mulching on the growth of avena sativa

    International Nuclear Information System (INIS)

    Implementation of suitable weed management practice is a critical step in crop production technology to reduce the competition for water, nutrients, space and light between the economically important crops and weeds. Mechanical, chemical or biological agents are being used by the farmer community to cope with the weed problem but these methods are specific in nature, expensive and detrimental to ecosystem. Allelopathy is a cost-effective and environment friendly approach replacing the previous techniques. Therefore, keeping in view the role of rice mulching in weed management, the present study was designed to manipulate the allelopathic traits of rice for the control of Avena sativa in a field trial during which it was grown in non-mulch and rice mulch regimes of different concentrations. (author)

  16. Research Advances in Soybean Allelopathy%大豆化感作用研究进展

    Institute of Scientific and Technical Information of China (English)

    孔菲

    2013-01-01

    Soybean is an important agricultural crop, and soybean continuous cropping barrier has been an important research topic. The research progress of the existing soybean allelopathy was reviewed in this paper. Soybean allelopathic phenomenon, mechanism of action and several applications in agricultural production was summarized in order to improve the quality and yield of soybeans.%简单概述大豆感化作用的表现方式、作用效果及作用对象,综合论述大豆化感作用机制的国内外研究进展,探讨其在农业生产种植模式和生物防治方面的应用情况,以期为大豆产量及品质提高提供理论参考。

  17. Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil

    Science.gov (United States)

    Juliano Gualtieri, Sonia Cristina; Rodrigues-Filho, Edson; Macías, Francisco Antonio

    2016-01-01

    The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant’s dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of

  18. 林木种间的化感作用%Effects of Allelopathy Among Tree Species

    Institute of Scientific and Technical Information of China (English)

    林文欢; 詹潮安; 陈红跃

    2011-01-01

    Effects of allelopathy among plants are a common phenomenon in natural world.Allelopathic effects play important roles on crop cultivation,weed control,pest control and plantation building.Collocation of tree species is a key factor in mixed plantation building.Effects of allelopathy among tree species play a crucial role in selection of tree species.The paper reviewed the research advances on allelopathic effects among the common tree species in mixed plantation in terms of collection and extraction of allelochemicals,authentication of allelochemicals and expressions of allelopathic effects.The research on the allelopathic effects among the tree species was aimed at providing scientific basis for tree species composition of plantation and giving service support to non-commercial forest.%植物化感作用是自然界普遍存在的一种现象,在农作物耕作、杂草控制、病虫害防治以及林木营造等方面发挥着重要作用。树种搭配是成功营造人工混交林的关键,林木种间的化感作用在混交树种的选择上起着重要作用。文中从化感物质的收集与提取、化感物质的鉴定以及化感作用的表达等方面,对人工混交林常见树种间化感作用的研究情况和成果进行综述,以期为混交林选择树种组合提供科学依据,为生态公益林建设服务。

  19. Prymnesium parvum revisited: relationship between allelopathy, ichthyotoxicity, and chemical profiles in 5 strains.

    Science.gov (United States)

    Blossom, Hannah E; Rasmussen, Silas A; Andersen, Nikolaj G; Larsen, Thomas O; Nielsen, Kristian F; Hansen, Per J

    2014-12-01

    Bioassay-guided discovery of ichthyotoxic algal compounds using in vivo fish assays is labor intensive, costly, and highly regulated. Since the mode of action of most known algal-mediated fish-killing toxins is damage to the cell membranes in the gills, various types of cell-based bioassays are often used for bioassay guided purification of new ichthyotoxins. Here we tested the hypothesis that allelopathy is related to ichthyotoxicity and thus that a microalgal bioassay can be used as a proxy for ichthyotoxicity by comparing the toxicity of five strains of Prymnesium parvum toward rainbow trout (Oncorhynchus mykiss, 10 g) and the microalga Teleaulax acuta. No relationship between median effective concentrations (EC50s) on fish and median lethal concentrations (LC50s) on algae was observed in the 5 strains showing that a microalgal bioassay cannot be used as a proxy for ichthyotoxicity. Fish were more sensitive to P. parvum with EC50s ranging from 6×10(3) to 40×10(3) cells ml(-1), compared to the test alga where LC50s ranged from 30×10(3) to nearly non-toxic at 500×10(3) cells ml(-1). In addition, the cellular concentrations of two recently suggested ichthyotoxins produced by P. parvum, the "golden algae toxins", GAT 512 and a novel GAT 510, did not show any relationship to either ichthyotoxicity or allelopathy, and are not the biologically relevant toxins, but are simply lipids found in algal chloroplasts. Finally, we demonstrate that the recently suggested ichthyotoxin, oleamide, could not be detected in any of the five P. parvum strains above the limit of detection, nor was it found in a (13)C-labeled strain. Instead we document that oleamide can easily be extracted from plastic materials, which may have been the source of oleamide reported previously. PMID:25456230

  20. Allelopathy of Bracken Fern (Pteridium arachnoideum): New Evidence from Green Fronds, Litter, and Soil.

    Science.gov (United States)

    de Jesus Jatoba, Luciana; Varela, Rosa Maria; Molinillo, José Maria Gonzalez; Ud Din, Zia; Juliano Gualtieri, Sonia Cristina; Rodrigues-Filho, Edson; Macías, Francisco Antonio

    2016-01-01

    The neotropical bracken fern Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) is described as an aggressive pioneer plant species. It invades abandoned or newly burned areas and represents a management challenge at these invaded sites. Native to the Atlantic Forest and Cerrado (Tropical Savanna) Brazilian biomes, P. arachnoideum has nevertheless become very problematic in these conservation hotspots. Despite some reports suggesting a possible role of allelopathy in this plant's dominance, until now there has been little evidence of isolated and individually identified compounds with phytotoxic activities present in its tissues or in the surrounding environment. Thus, the aim of this study was to investigate the allelopathic potential of P. arachnoideum by isolating and identifying any secondary metabolites with phytotoxic activity in its tissues, litter, and soil. Bioguided phytochemical investigation led to the isolation and identification of the proanthocyanidin selligueain A as the major secondary compound in the green fronds and litter of this fern. It is produced by P. arachnoideum in its green fronds, remains unaltered during the senescence process, and is the major secondary compound present in litter. Selligueain A showed phytotoxic activity against the selected target species sesame (Sesamum indicum) early development. In particular, the compound inhibited root and stem growth, and root metaxylem cell size but did not affect chlorophyll content. This compound can be considered as an allelochemical because it is present in the soil under P. arachnoideum patches as one of the major compounds in the soil solution. This is the first report of the presence of selligueain A in any member of the Dennstaedtiaceae family and the first time an isolated and identified allelochemical produced by members of the Pteridium species complex has been described. This evidence of selligueain A as a putative allelochemical of P. arachnoideum reinforces the role of

  1. Review of Studies on Allelopathy in Plants%植物化感作用研究动态

    Institute of Scientific and Technical Information of China (English)

    王春晴; 刘强; 李蕾

    2011-01-01

    In recent years, studies on allelopathy in plants were very active both at home and abroad. But most of the studies lack the in-depth study of the allelopathy mechanism. Hie species, release ways, influencing factors, function mechanism and mitigation methods of allel-ochemicals were reviewed based on the domestic and international researches.%近年来,国内外对植物化感作用的研究十分活跃.但是很多研究缺乏对化感作用机制的深入研究.结合国内外研究的现况,就化感物质的种类、作用途径、影响化感物质产生和释放的因素、化感物质的作用机理以及化感作用的缓解办法进行了综述.

  2. 国内植物化感作用研究概况%Briefly Research on Allelopathy in China

    Institute of Scientific and Technical Information of China (English)

    和丽忠; 陈锦玉; 董宝生; 李世萍

    2001-01-01

    @@ 1前言 植物在其生长发育过程中,通过排出体外的代谢产物(化学物质)而对另一种植物包括微生物产生促进或抑制作用,这种现象称为植物化感作用(简称化感作用)(Allelopathy).

  3. Phenolic acid substances and Allelopathy mechanisms%酚酸物质及其化感作用

    Institute of Scientific and Technical Information of China (English)

    吴凤芝; 赵凤艳; 马凤鸣

    2001-01-01

    阐述了化感作用(Allelopathy)的涵义,具有化感化用的酚酸物质的来源,酚酸物质化感作用的可能机制,并从连作障碍的角度分析了酚酸物质在连作障碍中的自毒作用,提出了减轻化感物质毒害的措施.

  4. The Impact of Competition and Allelopathy on the Trade-Off between Plant Defense and Growth in Two Contrasting Tree Species.

    Science.gov (United States)

    Fernandez, Catherine; Monnier, Yogan; Santonja, Mathieu; Gallet, Christiane; Weston, Leslie A; Prévosto, Bernard; Saunier, Amélie; Baldy, Virginie; Bousquet-Mélou, Anne

    2016-01-01

    In contrast to plant-animal interactions, the conceptual framework regarding the impact of secondary metabolites in mediating plant-plant interference is currently less well defined. Here, we address hypotheses about the role of chemically-mediated plant-plant interference (i.e., allelopathy) as a driver of Mediterranean forest dynamics. Growth and defense abilities of a pioneer (Pinus halepensis) and a late-successional (Quercus pubescens) Mediterranean forest species were evaluated under three different plant interference conditions: (i) allelopathy simulated by application of aqueous needle extracts of Pinus, (ii) resource competition created by the physical presence of a neighboring species (Pinus or Quercus), and (iii) a combination of both allelopathy and competition. After 24 months of experimentation in simulated field conditions, Quercus was more affected by plant interference treatments than was Pinus, and a hierarchical response to biotic interference (allelopathy competition competition) was observed in terms of relative impact on growth and plant defense. Both species modulated their respective metabolic profiles according to plant interference treatment and thus their inherent chemical defense status, resulting in a physiological trade-off between plant growth and production of defense metabolites. For Quercus, an increase in secondary metabolite production and a decrease in plant growth were observed in all treatments. In contrast, this trade-off in Pinus was only observed in competition and allelopathy + competition treatments. Although Pinus and Quercus expressed differential responses when subjected to a single interference condition, either allelopathy or competition, species responses were similar or positively correlated when strong interference conditions (allelopathy + competition) were imposed.

  5. 苔藓植物化感作用研究综述%Review on the Study of Allelopathy Effects of Bryophytes

    Institute of Scientific and Technical Information of China (English)

    刘俊华; 王书平; 马海玲

    2014-01-01

    化感作用是自然界广泛存在的一种物种克生现象,对各生态系统类型具有重要影响。苔藓植物广泛分布于陆地生态系统中,已有的苔藓化感作用研究主要为化感作用的生物测定,整体上尚处起步阶段。该文简要阐述了苔藓植物化感研究的基础,介绍了近年来取得的主要进展,并重点就苔藓植物化感作用研究中存在的问题和今后的发展进行了探讨。%Allelopathy refers to the chemical inhibition of one species by another species,with releasing the inhibitory chemicals into the environment where it affects the development and growth of neighboring plants,and the plant allelopathy has an important influence on all ecosystems. Bryophytes are widespread in terrestrial ecosystems,but the researches on plant allelopathy are just beginning,which rest on the bioas-say of allelopathy. This paper introduced the feasibility of bryophytes allelopathy research ,elucidated the progress of research on the bryophytes allelopathy in the past decades,discussed the existing problems and direction in the field of bryophytes allelopathy.

  6. Prymnesium parvum revisited: Relationship between allelopathy, ichthyotoxicity, and chemical profiles in 5 strains

    Energy Technology Data Exchange (ETDEWEB)

    Blossom, Hannah E., E-mail: hblossom@bio.ku.dk [Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør (Denmark); Rasmussen, Silas A. [Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs Lyngby (Denmark); Andersen, Nikolaj G. [Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør (Denmark); Larsen, Thomas O.; Nielsen, Kristian F. [Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs Lyngby (Denmark); Hansen, Per J. [Marine Biological Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør (Denmark)

    2014-12-15

    Highlights: • Five strains of P. parvum were tested for toxicity towards rainbow trout and microalgae. • Toxicity towards microalgae was not correlated to toxicity towards fish. • A microalgal bioassay cannot be used as a reliable proxy for ichthyotoxicity. • Concentrations of GATs were low and not correlated to effects on fish or on algae. • P. parvum does not produce oleamide based on {sup 13}C labeling and extraction in glass. - Abstract: Bioassay-guided discovery of ichthyotoxic algal compounds using in vivo fish assays is labor intensive, costly, and highly regulated. Since the mode of action of most known algal-mediated fish-killing toxins is damage to the cell membranes in the gills, various types of cell-based bioassays are often used for bioassay guided purification of new ichthyotoxins. Here we tested the hypothesis that allelopathy is related to ichthyotoxicity and thus that a microalgal bioassay can be used as a proxy for ichthyotoxicity by comparing the toxicity of five strains of Prymnesium parvum toward rainbow trout (Oncorhynchus mykiss, 10 g) and the microalga Teleaulax acuta. No relationship between median effective concentrations (EC{sub 50}s) on fish and median lethal concentrations (LC{sub 50}s) on algae was observed in the 5 strains showing that a microalgal bioassay cannot be used as a proxy for ichthyotoxicity. Fish were more sensitive to P. parvum with EC{sub 50}s ranging from 6 × 10{sup 3} to 40 × 10{sup 3} cells ml{sup −1}, compared to the test alga where LC{sub 50}s ranged from 30 × 10{sup 3} to nearly non-toxic at 500 × 10{sup 3} cells ml{sup −1}. In addition, the cellular concentrations of two recently suggested ichthyotoxins produced by P. parvum, the “golden algae toxins”, GAT 512 and a novel GAT 510, did not show any relationship to either ichthyotoxicity or allelopathy, and are not the biologically relevant toxins, but are simply lipids found in algal chloroplasts. Finally, we demonstrate that the recently

  7. Prymnesium parvum revisited: Relationship between allelopathy, ichthyotoxicity, and chemical profiles in 5 strains

    International Nuclear Information System (INIS)

    Highlights: • Five strains of P. parvum were tested for toxicity towards rainbow trout and microalgae. • Toxicity towards microalgae was not correlated to toxicity towards fish. • A microalgal bioassay cannot be used as a reliable proxy for ichthyotoxicity. • Concentrations of GATs were low and not correlated to effects on fish or on algae. • P. parvum does not produce oleamide based on 13C labeling and extraction in glass. - Abstract: Bioassay-guided discovery of ichthyotoxic algal compounds using in vivo fish assays is labor intensive, costly, and highly regulated. Since the mode of action of most known algal-mediated fish-killing toxins is damage to the cell membranes in the gills, various types of cell-based bioassays are often used for bioassay guided purification of new ichthyotoxins. Here we tested the hypothesis that allelopathy is related to ichthyotoxicity and thus that a microalgal bioassay can be used as a proxy for ichthyotoxicity by comparing the toxicity of five strains of Prymnesium parvum toward rainbow trout (Oncorhynchus mykiss, 10 g) and the microalga Teleaulax acuta. No relationship between median effective concentrations (EC50s) on fish and median lethal concentrations (LC50s) on algae was observed in the 5 strains showing that a microalgal bioassay cannot be used as a proxy for ichthyotoxicity. Fish were more sensitive to P. parvum with EC50s ranging from 6 × 103 to 40 × 103 cells ml−1, compared to the test alga where LC50s ranged from 30 × 103 to nearly non-toxic at 500 × 103 cells ml−1. In addition, the cellular concentrations of two recently suggested ichthyotoxins produced by P. parvum, the “golden algae toxins”, GAT 512 and a novel GAT 510, did not show any relationship to either ichthyotoxicity or allelopathy, and are not the biologically relevant toxins, but are simply lipids found in algal chloroplasts. Finally, we demonstrate that the recently suggested ichthyotoxin, oleamide, could not be detected in any of the

  8. Allelopathy and Its Applications in Weed Control%化感作用及其在杂草防除中的应用

    Institute of Scientific and Technical Information of China (English)

    石旭旭; 王红春; 高婷; 娄远来

    2013-01-01

    Allelopathy is widely present in the plant kingdom and has great potential for weed control.We mainly discussed the determination of allelopathy,the release pathways of allelochemicals,the mechanism of action of allelopathic compounds,and the application and potential of allelopathy for weed control.%化感作用在植物界中广泛存在,在杂草防除方面潜力巨大.重点对化感作用的判定、化感物质的释放途径、化感作用的作用机制及其在杂草防除中的应用进行了讨论,并对化感作用在杂草防除中的应用方式和应用潜力进行了探讨.

  9. Allelopathy in a leguminous mangrove plant, Derris indica: protoplast co-culture bioassay and rotenone effect.

    Science.gov (United States)

    Inoue, Aya; Mori, Daisuke; Minagawa, Reiko; Fujii, Yoshiharu; Sasamoto, Hamako

    2015-05-01

    To investigate allelopathic activity of a leguminous mangrove plant, Derris indica, the 'Protoplasts Co-culture Method' for bioassay of allelopathy was developed using suspension culture. A suspension culture was induced from immature seed and sub-cultured in Murashige and Skoog's (MS) basal medium containing 10 μM each of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA). The protoplasts were isolated using the separate wells method with 2% each of Cellulase RS, Driselase 20 and Macerozyme R10 in 0.4 M mannitol solution. Protoplast cultures of D. indica revealed that high concentrations of cytokinins, BA and thidiazuron, were effective for cell divisions. The co-cultures of D. indica protoplasts with recipient lettuce protoplasts using 96 multi-well culture plates were performed in MS basal medium containing 0.4 M mannitol solution and 1 μM 2,4-D and 0.1 μM BA. The protoplast density of D. indica used in co-culturing varied from 6 x 10(3) - 10(5) / mL. Very strong inhibitory allelopathic effects of D. indica protoplasts on lettuce protoplast growth were found. A similar strong inhibitory allelopathic activity of dried young leaves on lettuce seedling growth was also observed by using the sandwich method. Rotenone, which is a component of Derris root, dissolved in DMSO, was highly inhibitory on the growth of lettuce protoplasts in culture and this could be one of the causes of the strong allelopathic activity of D. indica.

  10. Seaweed-coral interactions: variance in seaweed allelopathy, coral susceptibility, and potential effects on coral resilience.

    Directory of Open Access Journals (Sweden)

    Roberta M Bonaldo

    Full Text Available Tropical reefs are in global decline with seaweeds commonly replacing corals. Negative associations between macroalgae and corals are well documented, but the mechanisms involved, the dynamics of the interactions, and variance in effects of different macroalgal-coral pairings are poorly investigated. We assessed the frequency, magnitude, and dynamics of macroalgal-coral competition involving allelopathic and non-allelopathic macroalgae on three, spatially grouped pairs of no-take Marine Protected Areas (MPAs and non-MPAs in Fiji. In non-MPAs, biomass of herbivorous fishes was 70-80% lower, macroalgal cover 4-9 fold higher, macroalgal-coral contacts 5-15 fold more frequent and 23-67 fold more extensive (measured as % of colony margin contacted by macroalgae, and coral cover 51-68% lower than in MPAs. Coral contacts with allelopathic macroalgae occurred less frequently than expected by chance across all sites, while contact with non-allelopathic macroalgae tended to occur more frequently than expected. Transplants of allelopathic macroalgae (Chlorodesmis fastigiata and Galaxaura filamentosa against coral edges inflicted damage to Acropora aspera and Pocillopora damicornis more rapidly and extensively than to Porites cylindrica and Porites lobata, which appeared more resistant to these macroalgae. Montipora digitata experienced intermediate damage. Extent of damage from macroalgal contact was independent of coral colony size for each of the 10 macroalgal-coral pairings we established. When natural contacts with Galaxaura filamentosa were removed in the field, recovery was rapid for Porites lobata, but Pocillopora damicornis did not recover and damage continued to expand. As macroalgae increase on overfished tropical reefs, allelopathy could produce feedbacks that suppress coral resilience, prevent coral recovery, and promote the stability of algal beds in habitats previously available to corals.

  11. Research Progress on Garlic Allelopathy and Its Utilization%大蒜化感作用及其利用研究进展

    Institute of Scientific and Technical Information of China (English)

    丁海燕; 程智慧

    2014-01-01

    近年来关于大蒜化感作用的研究日益增多,它在农业生产中的利用潜力逐渐被人们发现。本文主要从大蒜化感现象的发现、化感作用机理、化感物质鉴定、化感作用利用以及化感作用研究方法等方面进行讨论,对大蒜化感作用研究存在的问题和发展方向进行综合评述。%In recent years,studies on Garlic(Allium sativum L.)allelopathic effect are increasing day by day. Its utilization in agricultural production has gradually been found out. This paper mainly focuses on the discussion about discovery of garlic allelopathy phenomena,allelopathy mechanism,identification of allelochemicals,allelopathy utilization,research methods,etc. The paper also conducts comprehensive review on existing problems and development direction of garlic allelopathy research.

  12. Study on Status of Allelopathy in Forestry%化感作用在林业中的研究现状

    Institute of Scientific and Technical Information of China (English)

    马艳丽

    2012-01-01

    The allelochemicals sources, types and collection methods were introduced in this paper. Allelopathic impact on tree growth and forest allelopathy manifestations of the two aspects described allelopathic effects of trees were studied. Then summarized the potential applications of allelopathy in forestry. Finally, the problems of allelopathy in forestry Research was point out. And the future research direction of allelopathy in forestry was prospected.%综合介绍了化感物质的来源、种类及收集方法,并分别从化感对林木生长的影响和林木化感作用表现形式两大方面阐述了林木的化感效应。接着对化感作用在林业上的应用潜力进行了归纳。最后指出目前林业研究化感作用所存在的问题,并对今后林业中化感作用的研究方向进行展望。

  13. Allelopathy of Decomposing Liquids from Tobacco Roots on Lettuce Seeds%烟草根系腐解液对莴苣的化感作用

    Institute of Scientific and Technical Information of China (English)

    牛丽娜; 周冀衡; 柳均

    2011-01-01

    The allelopathy of decomposing liquids from roots of tobacco K326 on lettuce seeds was studied.results demonstrated that the decomposing liquids from tobacco roots had strong allelopathy on seed germination and seedling growth of lettuce; the inhibitory strength of integrated allelopathy of different components mainly expressed as acid soluble components>neutral components>alkaline soluble components>decomposing stock solution, while the promoting strength of allelopathy showed opposite.Therefore, it is suggested that attention should be paid to deal with tobacco withered roots after harvest during tobacco production.%以莴苣种子作为受体材料,研究了烟草K326根系腐解液的化感作用.结果表明:烟草根系腐解液对莴苣种子萌发和幼苗生长具有较强的化感作用,不同组分的综合化感抑制强度主要表现为酸溶性组分>中性>碱溶性组分>腐解原液,而化感促进强度则与之相反.因此,在烟草农业生产中,应重视对烟叶采收后烟根等残体物的处理.

  14. Advances in studies on allelopathy of medicinal plants in China%我国药用植物化感作用研究进展

    Institute of Scientific and Technical Information of China (English)

    张爱华; 郜玉钢; 许永华; 雷锋杰; 张连学

    2011-01-01

    This review introduced the importance and significance of allelopathy in medicinal plant, analyzed the reasons for allelopathy in medicinal plant, described the types of allelochemicals, reviewed the research methods and clarified the mechanism of allelopathy, and investigated the main problems about allelopathic reaearches on medicinal plants. Based on those, the paper points out the problems in the current study on allelopathy of the medicinal plants.%介绍化感作用在药用植物研究中的重要性及意义,分析了药用植物产生化感作用的原因,综述药用植物中存在的化感物质种类及其化感作用研究方法,同时阐述了其化感作用产生的机制,并对药用植物化感作用研究中存在的主要问题进行了深入剖析,在此基础上指出药用植物化感作用研究需要加强的方向.

  15. Allelopathy of Pseudomonas fluorescens: A preliminary study%荧光假单胞杆菌化感作用的初步研究

    Institute of Scientific and Technical Information of China (English)

    慕小倩; 杨超; 王硕

    2005-01-01

    The study on the allelopathy of Pseudomonas fluorescens showed that 200 times dilution of its cultured solution could restrain the growth of all test crops, 400 times dilution showed a weak restraining effect on most crops,while 600 times dilution had some stimulating effect. The effects differed with crop varieties.

  16. 淡水生态系统中的他感作用研究进展%Development of Research of Allelopathy in Freshwater Ecosystem

    Institute of Scientific and Technical Information of China (English)

    金秋; 金则新; 奚立民

    2012-01-01

    综述了目前淡水生物间他感作用的相关报导,给出了他感作用来源生物、他感物质和他感作用结果.并对淡水生物所产生的他感物质的种类及其作用模式,包括抑制酶活性、抑制光合作用等以及影响淡水生物间他感作用的因子,包括营养盐、非营养因子和微生物作了叙述和分析.阐述了淡水生物间他感作用的应用前景和目前研究所存在的问题,并对本研究领域未来的发展提出了展望.%This article reviewed the relevant reports on allelopathy in freshwater organisms up to the present,and gave the donor organisms of allelopathy, allelochemicals and the results of allelopathy. The categories and active modes of al-lelochemicals including inhibition of activity of enzyme,inhibition of photosynthesis etc.,and factors which can influence the effectiveness of the allelopathy of freshwater organisms including nutrients, non-nutrient factors and microorganisms were specified and analyzed. The application perspectives of allelopathy in freshwater organisms and problems lied in the relevant research works were expatiated. The future development prospect of this research fields was brought forward.

  17. Allelopathy in saline agricultural land: Vegetation successional changes and patch dynamics.

    Science.gov (United States)

    Mahmood, K; Malik, K A; Sheikh, K H; Lodhi, M A

    1989-02-01

    allelopathy may be a factor in determining growth and distribution of plants in saline or sodic soils.

  18. Study on Allelopathy of Narcissus pseudonarcissus%几种荷兰水仙的化感作用初探

    Institute of Scientific and Technical Information of China (English)

    刘小磊; 马晓红; 史益敏

    2011-01-01

    Four narcissus varieties, Delibes, Dutch Master, Mount Hood, Pinza were used to study allelopathy. The results showed that the allelopathy responses of four narcissus varieties are in the following order :Delibes>Dutch Master>Mount Hood>Pinza. The water extract from Delibes bulb could affect root and shoot elongation of Chinese cabbage, radish, lettuce, tall fescue and ryegrass. Besides, it reduces the chlorophyll content in tall fescue and ryegrass. Alcohol, acetone and methanol were tested as the solvent and their extracts could inhibit development of radish seeds, in which alcohol extract has the most obvious effect, followed by methanol extract and acetone extract.%对“德拉勃”、“荷兰船长”、“头巾”、“滨莎”4个荷兰水仙品种进行了化感作用研究.结果表明荷兰水仙具有化感作用,化感作用强度顺序为:德拉勃>荷兰船长>头巾>滨莎,鳞茎片水提液对白菜、萝卜、生菜、高羊茅、黑麦草种子胚根和胚芽生长均有抑制作用,对发芽期的高羊茅和黑麦草的叶绿素合成产生抑制作用.以乙醇、丙酮、甲醇作为提取剂,鳞茎片乙醇提取液的化感抑制作用最强,甲醇次之,丙酮最弱.

  19. 植物化感作用在控制水华藻类中的应用%Application of Plant Allelopathy in Controlling of Algal Bloom

    Institute of Scientific and Technical Information of China (English)

    邹华; 邓继选; 朱银

    2012-01-01

    伴随着水环境污染,水体中藻类疯长形成的“水华”、“赤潮”现象日益严重.各种化学、物理、生物方法被用于抑制藻类的生长,但这些方法都存在不易控制、成本高、易破坏生态等问题.利用植物化感作用抑制藻类生长具有生态安全和灵敏高效等优点,对湖泊富营养化的生态控制具有非常重要的意义.作者介绍了植物化感抑藻的研究进展,归纳了化感作用的种类和化感物质的化学成分,并讨论了植物化感抑藻的作用机制、抑藻机理,最后对植物化感作用在抑藻方面的研究前景进行了展望.%With the serious water pollution, the "algal bloom", "red tide" formed by the overpopulation of algal is getting worse. At present, different methods including chemical, physical, biological were used to inhibit the growth of algae in polluted water. However, the characteristics of these methods are difficult controlling, high cost, and damaging the ecology. In order to develop a low cost and ecologically safe method to inhibit the growth of algae, plant allelopathy is introduced. In this review, the research progress of algal -inhibition with plant allelopathy was introduced, the types of plant allelopathy and the chemical composition of allelo-chemicals were summarized , the mechanisms and perspective of plant allelopathy were discussed.

  20. The Allelopathy of Eucalyptus on Several Crops and Weeds%桉树对几种农作物和杂草的化感作用研究

    Institute of Scientific and Technical Information of China (English)

    田雪晨; 陈贤兴

    2014-01-01

    通过培养皿法和盆栽法对巨桉(Eucalyptus grandis Hill ex Maiden)、邓恩桉(Eucalyptus dunnii Maiden)的浸出溶液的化感作用进行了研究。研究结果表明,其对玉米(Zea mays)、小麦(Triticum aestivum),萝卜(Raphanus sativus)、绿豆(Vigna radiata)四种农作物的发芽指数和发芽率都有不同程度的抑制作用,但对幼苗生长的抑制作用不太明显;同时,还对土壤种子库中的杂草种子萌发有明显的抑制作用。这说明化感作用是这两种桉树的林下很少有其他植物,容易造成水土流失的原因之一。%The wuthors analyzed the allelopathy of the leaching liquor of Eucalyptus grandis Hill ex Maiden and Eucalyptus dunnii Maiden by the culture dish method and pot-culture method. According to the research,it is found that the Allelopathy restrict in a certain degree the pullulation index and pullulation rate of Zea mays, Triticum aestivum,Raphanus sativus and Vigna radiata,while the restriction effect doesn’t evident for the growing of young seeding. Meanwhile,the allelopathy keeps down the sprouting why of weed seeds in soil seed bank. So the allelopathy is one of the reasons that there are few other plants living under these two eucalyptus where mudslide happens frequently.

  1. The Impact of Competition and Allelopathy on the Trade-Off between Plant Defense and Growth in Two Contrasting Tree Species

    OpenAIRE

    Fernandez, Catherine; Monnier, Yogan; Santonja, Mathieu; Gallet, Christiane; Weston, Leslie A; Prévosto, Bernard; Saunier, Amélie; Baldy, Virginie; Bousquet-Mélou, Anne

    2016-01-01

    In contrast to plant-animal interactions, the conceptual framework regarding the impact of secondary metabolites in mediating plant-plant interference is currently less well defined. Here, we address hypotheses about the role of chemically-mediated plant-plant interference (i.e., allelopathy) as a driver of Mediterranean forest dynamics. Growth and defense abilities of a pioneer (Pinus halepensis) and a late-successional (Quercus pubescens) Mediterranean forest species were evaluated under th...

  2. The impact of competition and allelopathy on the trade-off between plant defense and growth in two contrasting tree species

    OpenAIRE

    Catherine eFERNANDEZ; Yogan eMONNIER; Mathieu eSANTONJA; Christiane eGALLET; Weston, Leslie A; Bernard ePREVOSTO; Amelie eSAUNIER; Virginie eBALDY; Anne eBOUSQUET-MELOU

    2016-01-01

    In contrast to plant-animal interactions, the conceptual framework regarding the impact of secondary metabolites in mediating plant-plant interference is currently less well defined. Here, we address hypotheses about the role of chemically-mediated plant-plant interference (i.e. allelopathy) as a driver of Mediterranean forest dynamics. Growth and defense abilities of a pioneer (Pinus halepensis) and a late-successional (Quercus pubescens) Mediterranean forest species were evaluated under thr...

  3. Sources and modes of action of invasive knotweed allelopathy: the effects of leaf litter and trained soil on the germination and growth of native plants

    Directory of Open Access Journals (Sweden)

    Madalin Parepa

    2012-05-01

    Full Text Available Invasive knotweeds, native to Eastern Asia, are among the most dominant plant invaders of European and North American temperate ecosystems. Recent studies indicate that one cause of this dominance might be allelopathy, but the possible sources and modes of action of this allelopathy are insufficiently understood. Here, we asked whether the invasive knotweed Fallopia × bohemica can exert allelopathic effects on native plants also through its leaf litter, or through persistent soil contaminants, and whether these affect the germination or growth of native plants. In a germination experiment with nine native species neither litter leachate, an aqueous extract of knotweed leaves added to the soil, nor trained soil with a history of Fallopia pre-cultivation suppressed the germination or early growth of natives. A mesocosm study with experimental native communities showed that the presence of F. × bohemica, although not a dominant in these communities, caused significant shifts of life-history strategy in two dominant natives, and that similar effects could be elicited through litter leachates or trained soil alone. However, there were hardly any effects on the biomass of natives. Our study indicates that knotweed allelopathy acts on the growth rather than germination of natives, and that soil contamination through persistent allelochemicals may not be a significant problem in habitat restoration. It also shows that allelopathic effects can sometimes be subtle changes in life-history and allocation patterns of the affected species.

  4. 植物化感作用在血吸虫病防治中的应用%Research and Application of Plant Allelopathy for Schstosomiasis Control

    Institute of Scientific and Technical Information of China (English)

    孙启祥; 彭镇华; 杨永峰

    2011-01-01

    This paper presents a complete description of the chemical components and the effects of plant allelopathy, as well as the criteria of plant selection for snail control. Research progresses in allelopathy for schslosomiasis control were briefly introduced, and its applied techniques were discussed in detail. This study will make positive contribution to the application of allelopathy in schstosomiasis control.%对抑螺植物的化感物质、化感作用、抑螺植物的标准进行了系统的阐述,对植物化感作用在血吸虫病防治中的研究情况进行了简要介绍,并重点对抑螺植物化感作用在血吸虫病防治上的应用技术进行了研讨,研究结果对植物化感作用在血吸虫病防治中的应用将具有积极的指导和推动作用.

  5. Review of Allelopathy of Eichhornia Crassipes in Lake Environment%浅析湖泊环境中凤尾莲的化感作用

    Institute of Scientific and Technical Information of China (English)

    孔燕

    2014-01-01

    Lake environmental protection and its related research have always been the focus of natural environment protection.The research on Eichhornia crassipes is a hotspot of eutrophication.Allelopathy of Eichhornia crassipes is significant to the ecological restore of the eutrophic lakes.The studies on allelopathy of Eichhornia crassipes was reviewed as well as its effects on other hydrophyte.The existing problems were pointed out.Future research on al-lelopathy of Eichhornia crassipes was suggested.%综述了凤尾莲抑藻化感作用及其对其他植物的影响,凤尾莲化感物质及其作用机理,其他植物对凤尾莲的化感作用。认为在下一步的工作中,应着重对凤尾莲化感作用涉及到的生理、生化和生态机制开展研究。

  6. 淡水水生植物化感控藻的研究进展%Research on Algalcontrol Ability of Allelopathy by Freshwater Macrophytes

    Institute of Scientific and Technical Information of China (English)

    胡建立; 周迟骏; 祈小丹; 周丽丽

    2012-01-01

    Algalcontrol ability of allelopathically is considered as one of the mechanisms that contribute to the stabilization of clear-water status in shallow lakes. The phylogeny of allelopathy on acquatic macrophytes was reviewed. The macrophyte species with anti-algal abilities were systematically summarized. The characteristics of anti-algal allelochemicals and the mechanism of the allelopathic of the allelopathic effect on algae were discussed. Subsequently, the algalcontrol mechanisms of allelopathy were explored, and the effects of environmental factors on phyto-allelopathic algae control were also demonstrated. Finally,application prospect of allelopathy in repair of aquatic ecological was prospected.%化感控藻是浅水湖泊保持清洁状态的机制之一.介绍了淡水高等水生植物化感作用的研究现状;总结了具有抑藻活性的水生植物种类;讨论了化感物质及其特性;对化感作用的抑藻机理进行了探索;阐述了环境因素对水生植物化感抑藻作用的影响;并且展望了化感作用在修复水生生态中的应用前景.

  7. Different Allelopathy of Eupatorium catarium Veldkamp in Hainan and Guangdong Regions%海南和广东不同地区假臭草化感作用的比较研究

    Institute of Scientific and Technical Information of China (English)

    刘振迪; 李光义; 李勤奋; 刘强

    2012-01-01

    利用生物检测法研究海南和广东几个不同地区假臭草(Eupatorium catarium Veldkamp)的化感作用,研究结果表明,不同地区的假臭草水提液对受试种子的萌发和幼苗生长的化感作用差异明显;海南地区的假臭草化感作用强于广东地区的假臭草的化感作用;广东不同地区假臭草化感作用由强到弱顺序为鹤山,阳江,徐闻;海南不同地区假臭草化感作用由强到弱顺序为琼中,琼海,儋州,三亚,海口.推测各地区假臭草化感作用差异可能是假臭草生境不同所致.%Use of biological test methods to determine the plant allelopathy differences of Eupatorium catarium Veldkamp from several different areas in Hainan and Guangdong regions, the results of the study showed that, the water extraction liquid of E. Catarium from different regions showed significant differences in allelopathy in germination of seeds and seedling growth; and E. Catarium in Hainan areas had stronger allelopathy than in Guangdong areas. In Guangdong, allelopathy of E. Catarium from different areas could be ordered as Heshan>Yangjiang>Xuwen. In Hainan, allelopathy of E. Catarium from different areas could be ordered as Qiongzhong>Qionghai>Danzhou>Sanya>Haikou. The different allelopathy of E. Catarium with different areas maight be as the result of the different habitats.

  8. 陆生植物化感作用的抑藻研究进展%Advance research on the allelopathy of terrestrial plants in inhibition of algae

    Institute of Scientific and Technical Information of China (English)

    倪利晓; 陈世金; 任高翔; 郝向阳

    2011-01-01

    Currently, it is a hot issue in environmental field to control algal bloom effectively and to treat the eutrophic water body. The allelochemical is the secondary metabolites what are produced by plants, bacteria, viruses and fungi. The allelopathy of aquatic autotrophs has drawn the most attention because it is believed to be high effective, low toxic and eco-friendly approach to control algal blooms. However, only a little research has been carried on the algicidal activity of the terrestrial plants. This paper made a systematic discussion on the evolution of the concept of the allelopathy, many kinds of biological inhibitions on algae and the mechanism of allelochemicals, ect. And it summarizes the research progress of the allelopathy of terrestrial plants in inhibition of algae by domestic and foreign scholars in recent years. The paper considered that the advantages of terrrstrial plants which were compared with aquatic ones embodied some aspects such as obvious allelopathy effect, rich allelopathy and noise immunity in aquatic biological environment, ect. And it also made a prospect for the research direction of the terrestrial plants in algal inhibition. The terrestrial plants and especially the compositae have a broad prospects in inhibition of algae. Finally, there are still some questions in several aspects such as a deep exploration and improvement of the allelopathy's extraction and identification, the research of the mechanism of allelochemicals, ecological safety and so on should be solved.%有效控制水华,治理富营养化水体是目前环境领域的研究热点和前沿.所谓化感物质,就是由植物、细菌、病毒和真菌所产生的二次代谢产物.利用水生植物的化感作用或化感物质抑制水体中藻类的爆发被认为是一种高效、低毒、环境亲合性好的方法而备受关注.然而,对于陆生植物应用于抑制藻类生长的研究却较少.文章在对化感作用的概念的演化、各种生物对

  9. 海洋微藻之间的化感作用研究进展%RESEARCH ADVANCES IN ALLELOPATHY OF MARINE MICROALGAES

    Institute of Scientific and Technical Information of China (English)

    禚鹏基; 赵卫红

    2007-01-01

    @@ 化感作用(Allelopathy),又称他感作用或相生相克,这一术语是由Molish (1937)最早提出的,用来指植物间的有益和有害的相互作用.Rice(1984)曾把它定义为:"一种植物,包括微生物,通过产生化学物质并排至环境中而对另一种植物或微生物产生直接和间接的有害效应."

  10. 药用植物化感作用的研究概况%Research on the Allelopathy of Medicinal Plants

    Institute of Scientific and Technical Information of China (English)

    张剑; 罗光明; 杨雅琴; 左月明; 熊诗华; 王蒙; 黄弦; 蔡财军

    2012-01-01

    对目前药用植物化感作用的基本概念及相关基础研究、化感自毒作用和综合应用等方面进行归纳和总结,并对其在药用植物中的进一步研究进行了探讨.%The basic concept,related studies,autotoxicity and integrated application of medicinal plants allelopathy were introduced,and its application in the study of medicinal plants was discussed.

  11. Research advance on influencing factors of plant allelopathy%植物化感作用影响因素研究进展

    Institute of Scientific and Technical Information of China (English)

    拱健婷; 张子龙

    2015-01-01

    化感现象广泛存在于植物界,植物之间的化感作用对生态系统有着不可忽视的影响。综合近年的文献,试图对影响植物化感作用的重要因素进行总结,旨在为探究植物化感作用机制、合理利用化感作用提供一定的理论参考。当前研究表明:1)遗传因素(供体种间差异、供体种内品种间差异、受体植物)影响植物的化感作用;2)植物生长阶段、不同营养器官化感物质的种类含量有差异,化感作用受此因素影响;3)环境条件,如生境、光照、温度、水分、土壤结构、营养条件等在不同程度上影响植物化感物质的产生、释放及其效应;4)动物侵害导致植物化感物质合成、释放能力增强,以抵御外界干扰环境,微生物参与化感物质的降解过程,从而影响其最终去向。最后对植物化感作用的研究进行了展望。%Allelopathy universally exists in the world, it would have a negligible impact among plants in the ecosystem. The current studies showed that plant allelopathy was genetic affected by the factors such as donor species difference, donor intraspecific differ-ences between species, receptors plant. Allelopathy was also affected by those like species of plant growth stage and the content of different vegetative organs of allelochemicals. Environmental conditions, such as habitat, illumination, temperature, moisture, soil structure and nutrient conditions affected the level, release and effect of plant allelochemicals in different extent. Animal invasion could cause the plant to synthesize and release the allelochemicals for enhancing ability to resist external interference. The microbial activities could control the pathway of the allelochemicals degradation. Also, the prospect of allelopathy research were discussed at last.

  12. 化感作用与资源竞争对假臭草入侵的影响%Effect of Allelopathy and Resource Competition on Eupatorium catarium Invasion

    Institute of Scientific and Technical Information of China (English)

    李光义; 刘强; 李勤奋

    2012-01-01

    Allelopathy and resource competition is widely existed in all plants for interspecific interaction and it is also the important weapon for plants successful invasion. The successful invasion of Eupatorium catarium resulted in resource competition and allelapathic inhibiting of other plants growth. As the starting point of the plant allelopathy and resource competition,this study regarded Eupatorium catarium as the donor,Styiosanthes guianensis cv. Reyan No. 2 as the receptor to build a symbiotic community for research of allelopathy and resource competition via an allelopathic - competitive separation method. The result showed that the active role of aboveground resources competition in Eupatorium catarium invasion was more than 20% , while the effect of the aboveground allelopathy,underground allelopathy and underground competition on Eupatorium catarium invasion was not obvious. Aboveground competition seems to be successful to promote Eupatorium catarium invasion. Aboveground allelopathy, underground allelopathy and underground competition might be available to play a role during the later period of invasion.%化感作用和资源竞争是植物之间普遍存在的一种种间相互作用,也是入侵植物成功入侵的重要“武器”.假臭草的成功入侵除了与其他植物争夺资源外,还通过化感作用抑制其他植物的生长.本研究以假臭草为供体,热研2号柱花草为受体,以植物的化感作用和资源竞争为切入点,应用化感-竞争分离法构建共生群落研究化感作用和资源竞争.结果表明,地上竞争对假臭草入侵的促进作用达到20%以上,而地上化感作用、地下化感和地下竞争对假臭草入侵的影响不明显.地上竞争促进假臭草成功入侵,地上化感作用、地下化感作用和地下竞争可能在入侵后期才发挥作用.

  13. 瑞香狼毒化感作用研究%Study on Allelopathy of Stellera chamaejasme

    Institute of Scientific and Technical Information of China (English)

    韩国君; 夏继桥

    2012-01-01

    The extracting solution from Stellera chamaejasme L. Was used to study its effects on seed germination and seedling growth of five plants, Chenopodium album L., Portulaca oleracea L., Leonurus heterophyllus Sweet., Amaranthus hypochondriacus L. And Celosia cristata L.. The results revealed the existance of allelopathy of 5. Chamaejasme L., which had different levels of affection on seed germination when using distinctive extracting solvents such as distilled water, ethanol and acetone. All the three kinds of extracting solution from S. Chamaejasme L. Had significant inhibition effect on the seedling growth of L. Heterophyllus Sweet. There was obvious inhibitive influence on the fresh weight of shoot roots, plumules and seedlings of Chenopodium album L., L. Heterophyllus Sweet and Celosia cristata L., except the slight increase on the radicle growth of Portulaca oleracea L. And seedling growth of Amaranthus hypochondriacus L. By the extracting solvent of distilled water.%研究了瑞香狼毒(Stellera chamaejasme L.)提取液对藜(Chenopodium album L.)、马齿苋(Portulaca oleracea L.)、益母草(Leonurus heterophyllus Sweet.)、籽粒苋(Amaranthus hypochondriacus L.)、鸡冠花(Celosia cristata L.)等5种植物种子萌发和幼苗生长的影响.结果表明,瑞香狼毒化感作用是存在的,并且瑞香狼毒的水、乙醇、丙酮提取液对种子萌发的影响不同.3种瑞香狼毒提取液对益母草幼苗生长的影响强度一直最大,除瑞香狼毒水提取液对马齿苋幼根生长和籽粒苋幼苗生长略有促进外,其他溶剂提取液对其他几种植物苗根、幼芽和幼苗鲜重均有明显抑制作用.

  14. Allelopathy effect of rice straw on the germination and growth of Echinochloa crus-galli (L.) P. Beauv

    Science.gov (United States)

    Anuar, Fitryana Dewi Khairul; Ismail B., S.; Ahmad, Wan Juliana Wan

    2015-09-01

    to be conducted to determine the mode of action of the allelochemicals involved in rice allelopathy.

  15. Alelopatia e homeopatia no manejo da tiririca (Cyperus rotundus Allelopathy and homeopathy in the management of nutsedge (Cyperus rotundus

    Directory of Open Access Journals (Sweden)

    H.R.O. Silveira

    2010-01-01

    weed of difficult control, causing reduction of stand and yield of a wide variety of commercial crops. Due to its aggressiveness, reproduction capacity, high dispersion and rusticity, its control is difficult and costly. The aim of this work was to evaluate alternative methods of nutsedge control based on allelopathy and homeopathy. In the management with allelopathy, aqueous extracts of jack bean (Canavalia ensiformes, black velvet bean (Stizolobium aterrimum, rosemary pepper (Lippia sidoides and lemon grass (Cymbopogon citratus were tested. With homeopathy, the Hahnemannian centesimal scale was used, testing the 3CH, 6CH, 9CH and 12CH dynamizations. Both experiments were conducted in transparent Gerboxes containing washed coarse sand, 1 to 3 mm thick grains, and 10 healthy nutsedge tubers, distributed evenly within the container. After the application of the treatments, the containers were placed in a BOD germination chamber at 25 oC with a 12 hour photoperiod, where they remained for 15 days until the final evaluation. The extract presenting the best nutsedge management was rosemary pepper, which reduced plantlet emergence percentage and vigor, with the extract of this species causing a length reduction in the nutsedge plant higher than that of 2.5 kg ha-1 a.i. of atrazine, the herbicide used for comparison. The homeopathy treatment did not present a significant difference, not exhibiting the expected effect with its nutsedge control dynamizations. The lemon grass, black velvet bean and jack bean extracts did not present allelopathic effects. However the rosemary pepper extract was found to be promising as a nutsedge alternative management, with further studies being necessary to elucidate the chemical principles involved and its true action in the metabolism of the plant.

  16. 植物化感作用在蔬菜作物上的表现及其应用%Manifestation and Application of Allelopathy in Vegetable Crops

    Institute of Scientific and Technical Information of China (English)

    李大伟; 贾庆利; 巩振辉

    2004-01-01

    植物化感作用(Allelopathy)是化学生态学研究的一个重要方面。1937年德国科学家Molish首次提出此词,它是指各种植物(包括微生物)之间存在的一种化学相互作用,包括促进和抑制两个方面。植物主要是通过茎叶挥发、淋溶、根系分泌以及植物残体的腐解等途径向环境中释放化感物质,来影响周围植物(微生物)的生长和发育。化

  17. Research and mechanism on plant allelopathy inhibition marine red tide: A reviw%植物化感作用抑制海洋赤潮的研究与机理

    Institute of Scientific and Technical Information of China (English)

    边归国

    2013-01-01

    A fully introduce the terrestrial,freshwater aquatic,large algae and so on various plant allelopathy inhibit 19 species of marine red tide algae method,allelochemicals and inhibition mechanism.Preliminary analysis of the large algae and micro algae mutual inhibition,and plant allelopathy inhibition Marine red tide algae technology was discussed.%较全面地介绍了陆生、淡水水生、大型海藻等各种植物化感作用抑制19种海洋赤潮藻类的方法、化感物质和抑制机理,初步分析了大型海藻和微藻之间的相互抑制作用,并对植物化感作用抑制海洋赤潮藻类技术进行展望.

  18. Aquatic plant allelopathy emergency disposal of red tide and freshwater algal blooms%水生植物化感作用应急处置海洋赤潮和淡水水华

    Institute of Scientific and Technical Information of China (English)

    边归国

    2012-01-01

    In recent years, Allelopathy is becoming the new technology to control algae outbreaks. According to the research results at home and abroad, focus on the aquatic plant allelopathy, allelopathic algal material, algae emergency response methods, the red tide and algal blooms in freshwater emergency response and mechanism are reviewed, and the future development are to be Looking.%近年来,植物化感作用逐渐成为控制藻类暴发的一种新技术。根据国内外的研究成果,着重从水生植物化感作用、化感抑藻物质、应急处置藻类方法、海洋赤潮和淡水水华的应急处置及机理进行评述,并对该技术今后的发展予以展望。

  19. Research Advance on Allelopathy of Plant in Grassland Ecosystem%植物化感作用在草地生态系统中的研究进展

    Institute of Scientific and Technical Information of China (English)

    张玉娟; 唐士明; 邵新庆; 黄顶; 王堃

    2012-01-01

    植物的化感作用(allelopathy)是植物化学生态学研究的热点之一.在生态系统中化感植物通过淋溶、挥发、残体分解和根系分泌等过程,释放出化学物质,引起植物种间或种内的相互作用,产生有害或有利的影响.化感作用影响着群落的植物组成及分布格局、群落的演替、种子的保存和萌发以及氮循环等.主要对草地植物的化感物质种类、化感物质作用特点、释放途径、影响化感物质产生的因素以及化感物质提取方法进行了归纳和总结.同时,提出了草地植物化感研究存在的科学问题和应用前景.%Allelopathy of plant becomes one of hot topics in the field of plant chemical ecosystem. Chemical substances are released in environment via some processes, such as leaching, volatilization, residue decomposition and root exudation, producing interactions between plant species or in one species, which are positive or negative on surrounding plants and microorganisms. Allelopathy actions affect the community composition, distribution pattern, succession, the preservation and germination of seeds and the process of nitrogen circulation. The study mainly focused on the types, function characteristics, release ways, extract methods of allelochemical as well as the influence factors of production. It also proposed some scientific problems and application prospect in study on allelopathy of grassland plant.

  20. Dynamical Behaviors of Two Phytoplankton Species with Allelopathy on a Single Resource%单资源中带有化感作用的两种浮游植物的动力学行为

    Institute of Scientific and Technical Information of China (English)

    张利利; 裴永珍; 李长国

    2011-01-01

    讨论了带有化感作用机制的两种浮游植物的营养竞争模型,获得系统平衡点的存在性和稳定性条件.%A nutrient competition model between the two populations of phytoplankton species is established with allelopathy mechanism.Some conditions are proposed to guarantee the existence,and stability of equilibrium point.

  1. 化感作用对土壤酶影响的研究进展%The Status on the Research of Allelopathy under the Influence of Soil Enzyme

    Institute of Scientific and Technical Information of China (English)

    方斯文; 张爱华; 贾明慧; 雷锋杰; 张连学

    2012-01-01

    Soil enzyme was the important part in soil ecosystem, studies on soil enzymes contribute to deepen our understanding of soil ecosystem degradation mechanism and material circulation and energy flow. Allelopathy has the important influence on soil micro ecology environment. This article reviewed the influence of allelochemicals on soil enzyme activity in recent years, and prospected the application of soil enzymology in allelopathy. In order to find more effective soil improvement program, it was raised from the perspective of allelopathy of soil enzyme activity.%土壤酶是土壤生态系统中的重要组成部分,土壤酶的研究有助于加深理解土壤生态系统的退化机理及其物质循环和能量流动.化感作用对土壤微生态环境有着重要影响.因此总结了近几年化感物质对土壤酶活性影响的主要研究成果,对土壤酶学在化感作用中的应用进行展望,提出从化感作用的角度研究土壤酶活性,从而找出更有效的土壤改良方案.

  2. 紫茎泽兰和一年蓬浸提液化感作用的对比研究%Allelopathy of Water-extracted Solution of Eupatorium adenophorum and Erigeron annuus on the Sprouting of Radish Seeds

    Institute of Scientific and Technical Information of China (English)

    谭永钦; 胡兵; 熊程; 李丽; 王永模

    2011-01-01

    The allelopathy of Eupatorium adenophorum was studied by cultivating radish seeds in the water extraction of Eupatorium adenophorum root, stem and leaves,and compared with that of Erigeron annuus. Results showed that the extraction of Eupatorium adenophorum from every partion had inhibitory effect on sprouting of radish seeds; and the order of allelopathy was leafe >root >stem. At the concentration of 0.40 g/mL,the allelopathy of extration from Eupatorium adenophorum was stronger than that of Erigeron annuus and control, which meant that Eupatorium adenophorum had stronger allelopathy. It was suggested that allelopathy meda Eupatorium adenophorum more competitive than the local weeds, thus played an important role in its invasion and spreading.%采用根、茎和叶浸提液培养萝卜种子的方法研究了紫茎泽兰的化感作用,同时与本地杂草一年蓬的化感作用进行了比较.试验结果表明,紫茎泽兰各部位的浸提液对萝卜种子的萌发普遍具有抑制作用,化感强弱顺序为:叶>根>茎;在0.40g/mL的浓度下,紫茎泽兰根、茎、叶浸提液对萝卜种子胚根和胚芽的抑制作用均显著大于同浓度的一年蓬浸提液和空白对照组,表明紫茎泽兰比一年蓬具有更强的化感作用.紫茎泽兰化感作用在传播入侵过程中起着重要的作用,在与本地杂草竞争时具有优势.

  3. 栗与美国板栗化感作用的比较%Allelopathy comparison between Castanea mollissima and C.dentata

    Institute of Scientific and Technical Information of China (English)

    李晓娟; 王强; 倪穗; 阮晓; 王永红; 张焕; 王高峰

    2013-01-01

    以种子发芽率和发芽势为种子萌发参数,以胚根、胚芽长度和鲜重变化为幼苗生长参数,研究了栗(Castanea mollissima)叶水提取物对双子叶植物莴苣(Lactuca sativa)、萝卜(Raphanus sativus)、黄瓜(Cucumis sativus),和单子叶植物洋葱(Alliumcepa)、水稻(Oryza sativa)、小麦(Triticum aestivum)的化感作用;比较了美国板栗(Castanea dentata)与栗叶水提取物及经X-5大孔树脂分离获得的11个洗脱组分间的化感作用强弱;利用液相色谱-质谱联用技术结合标准物质的反证实验,解析了美国板栗与栗化感作用最强分离组分的物质结构.研究结果表明,栗叶化感效应强于美国板栗;美国板栗与栗化感作用最强分离组分中(5:5洗脱组分)存在绿原酸、对羟基苯甲酸、原儿茶酸和没食子酸等物质.在利用栗基因恢复美国板栗种群时,有必要考虑美国板栗与栗植物化学生态特性的差异.%Aims Castanea mollissima and C. dentata are typical chestnut species in Asia and North America, respectively. They play important roles in the ecology and economy in their existing forest ecosystems. Chestnut blight has caused catastrophic losses of C. dentata populations since 1904. It is especially important to understand the differences in chemical ecology characteristics between C. dentata and C. mollissima when scientists try to make use of blight resistance of C. dentata to help the recovery of C. mollissima populations in North America. The objective of this research is to compare the allelopathy effect of C. dentata and C. mollissima by leaf water extract bioassay method. Methods Using germination rate and vigor as seed germination parameters and radicle, plumule elongation and fresh weight change of seedling as seedling growth parameters, we studied the effect of water extract of C. mollissima leaves on dicotyledons lettuce, radish and cucumber and monocotyledons onion, rice and wheat. We compared the allelopathic

  4. Effect of seasonal variation in Sálvia allelopathy potential / Efeito da variação sazonal no potencial alelopático de Sálvia

    Directory of Open Access Journals (Sweden)

    Claudia Tatiana Araujo da Cruz-Silva

    2009-07-01

    Full Text Available The biosynthesis and the accumulation of the chemical composites that have allelopathy characteristics in Salvia officinalis L. (Lamiaceae are resulting from the secondary plant metabolism. The present work had as objective to analyze the allelopathic effects of aqueous extracts of fresh leaves of Sálvia collected during the seasons, obtained by decoction, static infusion and grinding, on the germination and development of seedlings of lettuce (Lactuca sativa L.. The experiment had 20 treatments (concentrations 0; 7.5; 15; 22.5 and 30%. The results had been submitted to the Tukey test, to the level at 5% probability. The appraised variables, germination percentage, the germination speed index (GSI, the growth of shoot and roots and abnormality formation of seedlings did not present a pattern of allelopathy in the different seasons, indicating a possible alteration in the plant metabolism in function of the seasonal variation in the plant ambient.A biossíntese e o acúmulo dos compostos químicos que conferem a característica alelopática em Salvia officinalis L. (Lamiaceae são resultantes do metabolismo secundário do vegetal. O presente trabalho teve como objetivo analisar os efeitos alelopáticos de extratos aquosos de folhas frescas de Sálvia coletadas durante as estações do ano, obtidos por decocção, maceração estática, infusão e trituração sobre a germinação e o desenvolvimento de plântulas de alface (Lactuca sativa L., totalizando 20 tratamentos nas concentrações 0; 7,5; 15; 22,5 e 30%. Os resultados obtidos foram submetidos ao teste de Tukey, ao nível de 5% de probabilidade. As variáveis avaliadas, porcentagem de germinação, índice de velocidade de germinação (IVG, crescimento da parte aérea e das raízes e formação de plântulas anormais não apresentaram um padrão de resposta alelopática nas diferentes estações do ano, indicando possível alteração no metabolismo vegetal em função da varia

  5. Allelopathy of Wedelia trilobata on Mungbean%三裂叶蟛蜞菊对绿豆的化感作用

    Institute of Scientific and Technical Information of China (English)

    陈秋平

    2014-01-01

    研究了三裂叶蟛蜞菊各器官水提液对绿豆种子萌发及其幼苗生长的影响。结果表明,各器官水提液浸种能显著降低绿豆种子发芽率,且发芽率随水提液浓度增大而降低;各器官水提液能显著抑制绿豆幼苗的生长,5d后绿豆平均根长随水提液浓度增大而变短;对绿豆种子萌发的化感作用从强到弱依次为茎>叶>全株>根。%The allelopathy of the water extract of organs of Wedelia trilobata L.on mungbean was studied .The results showed that the aqueous extracts of organs could significantly reduced the seed germination percentage and growth of mungbean .The seed germination percentage and average root length after 5 days decreased with the aqueous extracts con-centration increased .The aqueous extracts from different parts of W.trilobata.The effects order on the germination of mungbean were stem >leaf>whole plant>root.

  6. 牛尾蒿水浸液对几种植物种子萌发的化感作用%Allelopathy of Artemisia roxburghiana extract to plant seeds germination

    Institute of Scientific and Technical Information of China (English)

    李彦刚; 陈静; 张付斗

    2012-01-01

      Allelopathy is common in higher plants. Appling allelopathy to control farmland weeds is a new research trend. Artemisia species has been commonly used as medicinal plants in traditional Chinese medicine in China for a long time. To explore the application of Artemisia plants in weed control, the water extract of Artemisia roxburghiana Bess. was used to study the allelopathic effects on the germination of lettuce, amaranth, radish, ryegrass, and wild oat seed. The results show that it obviously inhibited the germination of seeds. Allelopathy of Artemisia roxburghiana Bess. has a significant different effects on dicotyledonous and monocotyledonous plants.%  植物化感作用在高等植物中普遍存在,而应用植物化感作用防除农田杂草是目前较为新颖的研究方向。蒿属植物早就是我国中医中常用的药用植物,为探究蒿属植物在农田生态除草方面的应用,选择资源较为丰富的牛尾蒿为研究对象,通过用牛尾蒿水浸提液对莴笋、小米菜、萝卜、黑麦草、野燕麦等植物种子发芽率的试验,表明牛尾蒿对这几种植物有明显的化感作用,并且对双子叶植物和单子叶植物的化感作用有明显的差异

  7. Allelopathy effects of Panax notoginseng root exudates on wheat under different nitrogen levels%不同氮素水平下三七根系分泌物对小麦的化感作用

    Institute of Scientific and Technical Information of China (English)

    拱健婷; 张子龙; 王雄飞

    2014-01-01

    In ordre to explore the allelopathy effect of Panax notoginseng root exudates under different nitrogen levels, the present study using Panax notoginseng seedlings and wheat plants as donor and receptor plants , respectively, was carried out.The results showed that Panax notoginseng root exudates exhibited inhibitory effect on wheat (M3 =-0.04).Compared with seedling growth, seed germination was more likely to be inhibited by the allelopathy effect of Panax notoginseng root exudates.With increased N level, the inhibitory effect on germination index increased in the order of excess N >normal N >deficient N.The shoot growth of wheat seedling was enhanced by allelopathy effect of Panax notoginseng root exudates, while the root growth was inhibited.Besides, it was noticed that the allelopathy effect of Panax notoginseng root exudates on wheat was related to the nitrogen level in solution.%为探讨三七在不同氮素水平下根系分泌物的化感作用,以三七种苗为供体植物,小麦为受体植物进行生物测定。结果表明,三七根系分泌物对小麦表现出化感抑制作用(敏感指数M3=-0.04)。从发育时期来看,小麦种子萌发阶段较幼苗生长阶段更易受化感抑制作用影响,且其发芽指数受抑程度随氮素水平的升高而逐渐增强,即过氮>正常>缺氮;在小麦幼苗生长阶段,三七根系分泌物对其地上部化感作用以促进为主,对根部生长则以抑制作用为主;且三七根系分泌物对小麦的化感作用与培养液氮素水平有关。

  8. 一类浮游生物植化相克时滞系统的概周期解的存在性%Existence of Almost Periodic Solution for a Delayed System of Plankton Allelopathy

    Institute of Scientific and Technical Information of China (English)

    胡猛; 王健

    2013-01-01

    By means of the properties of almost periodic system and Lyapunov-Razumikhin technique, the sufficient conditions are obtained for the existence of almost periodic solution for a delayed almost periodic system of plankton allelopathy.%研究了一类浮游生物植化相克时滞概周期系统,运用概周期系统的性质与Lyapunov-Razuminkhin技巧,给出了其存在严格正概周期解的充分条件.

  9. 化感作用在水土保持生物措施治理中的应用研究%Review on Allelopathy in the Application of Biological Measures of Soil and Water Conservation Management

    Institute of Scientific and Technical Information of China (English)

    陆茜; 张金池

    2013-01-01

    植物的化感作用是植被以小分子有机物为媒介调控种间和种内关系的机制,近年在水土保持生物措施中得到研究和应用。综述国内外化感作用在水土保持生物措施中的研究进展和应用潜力,重点评述化感作用在林地连栽障碍问题中的重要性和解决路径以及化感作用在优化植被结构中的应用;提出基于化感品种和化感物质数据库无缝对接基础数据库形成林草措施方案专家系统的设想。化感作用的研究方法和实验设计上需要充分模拟或结合实际生境,综合其它重要生态因子,使研究结果更可信和具有解释力。%Plant allelopathy is a sort of regulation mechanism for interspecific and intraspecific relations of vegetations with small molecule organic media ,which increasingly took place in the researches and applications of biological measures for soil and water conservation .The research developments and applicated potentials of plant allelopathy on biological measures in the soil and water conservation were reviewed ,underlining the vital role allelopathy plays in soil degradations ,its resolution and ,the optimizations of structure of vegetations .An en-vision about grass measures expert system was developed based on allelopathic species and allelochemicals da -tabases as well as their seamless connections to some basic databases .Plant allelopathy can not be separated as single significant factor from complex ecological processes .Research methods and experimental designs should be simulated or combine with natural habitats sufficiently and consolidate other important ecological factors to make the results more credible and explanatory .

  10. Study on Allelopathy of Root Extract from Grafted Watermelon%嫁接西瓜根系浸提液化感作用研究

    Institute of Scientific and Technical Information of China (English)

    陈淑芳; 吴芳芳

    2011-01-01

    Watermelon itself as receptor, the allelopathy of root water extract from grafted watermelon was studied by bioassay methods. The result showed that compared with the control, watermelon seed germination exhibited allelopathic promotion in 0.01 g/ml,0.02 g/ml and 0.04 g/ml root extract treatments,seed germination exhibited allelopathic inhibition in 0. 08 g/ml root extract treatment,in which the allelopathic potential of 0. 01 g/ml and 0.02 g/ml root extract treatment was better. In terms of watermelon seedling growth,root length or plant height improved and plant dry weight increased in 0. 01 g/ml and 0. 02 g/ml root extract treatments, which played allelopathic promotion on seedling growth. In 0.04 g/ml and 0.08 g/ml root extract treatments, watermelon seedling growth was inhibited, and the allelopathic potential of 0. 08 g/ml root extract treatment was the best. The change of MDA content explained that plant was injury by high concentration extract treatment and growth was inhibited. As a whole, allelopathy of root water extract from grafted watermelon was stimulatory in lower concentration and inhibitory in higher concentration.%以西瓜自身为受体,采用生物测定的方法,研究嫁接西瓜根系水浸液的化感作用.结果表明,与对照相比,0.01、0.02、0.04 g/ml浸提液处理对种子萌发有化感促进作用,0.08 g/ml浸提液处理表现为化感抑制作用,0.01 g/ml和0.02g/ml处理化感强度较大.从西瓜幼苗生长状况来看,0.01 g/ml和0.02 g/ml根系浸提液处理促进根系生长或植株苗的生长,苗干重增加,对西瓜幼苗生长起化感促进作用,0.04 g/ml和0.08 g/ml浸提液处理对西瓜幼苗生长起抑制作用,0.08 g/ml浸提液处理化感强度最大.幼苗体内MDA含量的变化,表明在较高浓度浸提液处理下,植株受到伤害,进而生长受抑.嫁接西瓜根系浸提液的化感作用整体表现为低促高抑.

  11. Allelopathy Effect of Ginger Rhizome Extract on Watermelon and Bitter Gourd%生姜浸提液对西瓜和苦瓜的化感作用

    Institute of Scientific and Technical Information of China (English)

    赖佳; 张莉; 李焕秀; 唐懿

    2014-01-01

    以不同浓度的生姜根茎浸提液为供体,以早佳8424西瓜和大白苦瓜为受体,采用培养皿滤纸法,初步研究了不同浓度生姜根茎浸提液对西瓜和苦瓜的化感作用。试验结果表明,当生姜根茎浸提液在2.5~20 g/L的浓度范围内,对西瓜和苦瓜的种子萌发和幼苗生长均具有促进作用,在低浓度时促进作用较为明显,随着浓度的升高促进作用减弱。当生姜浸提液浓度为2.5 g/L时,西瓜幼苗生长最好;浸提液浓度为5~10 g/L时,苦瓜幼苗生长最好。%We studied the allelopathy effect of ginger rhizome extract with different concentrations on seed germination and seedling growth of watermelon cultivar Zaojia 8424 and bitter gourd cultivar Dabikugua by using the culture plate and filter paper culture bioassay method. The results showed that 2.5-20 g/L ginger rhizome extract promoted the seed germination and seedling growth of watermelon and bitter gourd, and at lower concentration, the promoting effect of ginger rhizome extract was greater than that of the higher concentration, in addition, the promoting effect weakened gradually as the concentration increased. 2.5 g/L was the most beneficial concentration for watermelon seedling growth, while 5-10 g/L was the most advantageous concentration for bitter gourd seedling growth.

  12. 陆生植物对藻类化感抑制作用的研究进展%Research progress in the inhibition effect of terrestrial plant on algae allelopathy

    Institute of Scientific and Technical Information of China (English)

    江中央; 郭沛涌

    2011-01-01

    如何有效抑制藻类的生长、防治水华发生是目前水环境领域研究的热点和前沿问题之一.利用植物的化感作用抑藻作为一种新型的生物除藻技术而备受关注.阐述了陆生植物对水华微藻生长的抑制作用研究成果,论述了其对藻类生长的抑制作用方式、抑藻化感物质及种类,以及抑藻化感作用机理,并对植物化感抑藻前景进行了展望.%How to inhibit the growth of algae and to effectively control the existence of water bloom is a hot and front-line issue in water environmental field. The novel biological algae removing technology by making use of allelopathic effect of plants to inhibit the algae has received much concern. The research achievements of the inhibition effect of terrestrial plant on the growth of water bloom micro-algae are expounded. The modes of inhibition effect on algae growth,the substances and species of algae inhibiting allelopathy and the mechanism of algae inhibiting allelopathy are discussed. The foreground of plant allelopathic effect on algae inhibition is predicted.

  13. 紫茉莉种子水浸液对西瓜和枸杞的化感作用研究%Allelopathy of Water Extracts from Seeds of Mirabilis jalapa L. on Watermelon and Chinese Wolfbeery

    Institute of Scientific and Technical Information of China (English)

    张益民; 薛泽

    2012-01-01

    Allelopathy of water extracts from seeds of Mirabilis jalapa L. on watermelon and Chinese wolfberry were examined for the objective of providing the reference for the theoretical study of allelopathy. By using the techniques of laboratory bioassay, the effects of water extracts from seeds of Mirabilis jalapa L. on seeds germination and seedlings growth of watermelon and Chinese wolfberry were studied. The results showed; Treated with different concentrations water extracts from seeds of Mirabilis jalapa L. on seeds germination and seedlings growth of watermelon could be inhibited, and on germination of seed, height , fresh weigh and fresh weight of root of Chinese wolfberry could be promoted, the inhibition or facilitation increased with increased concentrations of the water extracts.%采用室内生物测定法,研究了紫茉莉种子水浸液对西瓜、枸杞种子萌发和幼苗生长的影响,以期为植物化感作用的理论研究提供参考.结果表明,不同浓度紫茉莉种子水浸液对西瓜种子萌发和幼苗生长表现为化感抑制作用,而对枸杞种子萌发,幼苗苗高、鲜重、根鲜重表现为化感促进作用,且表现为浓度效应.

  14. A review of belowground interspecific interactions and allelopathy in silvopasture systems%林草复合系统地下部分种间互作关系与化感作用研究进展

    Institute of Scientific and Technical Information of China (English)

    秦树高; 吴斌; 张宇清

    2011-01-01

    Silvopasture (forest-pasture complex), a sustainable land-use/management strategy, has been widely practised and increasingly researched worldwide against a background of global population explosion, exorbitant resource consumption and deterioration of eco-environments. In silvopasture systems, interspecific interaction relationships is one of the most important research foci. It directly relates to the results of this land-use/management strategy and research has progressively shown that the belowground interspecific interactions, and allelopathy play a more important role than aboveground interspecific interactions in system stability. This paper reviews and summarizes existing research on belowground interspecific interactions and allelopathy in silvopasture systems, and offers some suggestions for design and management of systems, for optimizing system structures and resource utility patterns, thereby reducing interspecific negative effects, and resulting in maximal comprehensive harvesting benefits. It is suggested that future research on belowground interspecific interactions and allelopathy, in silvopasture systems, focus on: the association among allelopathy, belowground and aboveground interspecific interactions, the water & nutrition coupling utilization effect of woody plants and herbage, the separate mechanisms of woody and herbaceous roots centralized layers, finding and collating appropriate hydraulic life trees in systems, the response of belowground interspecific interaction between woody plants and herbage to global climate change, researching allelopathy for optimization of systems species structure and in ecological management of silvopasture systems.%林草复合系统作为一种具有可持续发展特点的土地利用方式,已在全球范围内得到了广泛的应用和研究,其经营的成败通常是由各生物组分之间的相互作用关系所决定.目前,林草复合系统的经营者比较重视对系统地上部分种间互

  15. Current research on plant allelopathy and its application in agricultural production%植物化感作用的研究现状及其在农业生产中的应用

    Institute of Scientific and Technical Information of China (English)

    杨田甜; 杜海荣; 陈刚; 邓鹏; 甄伟伟

    2012-01-01

    Allelopathy is commonly defined as the direct or indirect effects (stimulative or inhibitory) by one plant or another through production of chemical compounds that escape into environment, this phenomenon exists extensively in the agro-ecosystem, together with the plants' competition on light, water, nutrients and space, constitutes the interaction between different plants. In agricultural production, plant allelopathy influences the monoculture, crop rotation, crop cover, and takes an important role in getting rid of the obstacles of continuous cropping, regulating crops growth and preventing the pests and weeds and so on. In recent years, plant allelopathy was paid more attention by researchers all around the world. The categories, ways of releasing allelochemicals, and the research background, latest development, as well as the prospects of plant allelopathy applied in agricultural production were reviewed in this paper based on many references collected. Then the potential values in development of new varieties were also proposed. The further research in this field will be mainly focused on the cultivation of new allelopathic varieties which can avoid pests and suppress weeds as well as the application of plant-based pesticides. Furthermore, allelochemicals can be used as herbicides and the possibility of artificial synthesis will be investigated so that the pollution of chemical herbicides can be reduced. In the end, the existing problems and direction in the study on plants allelopathy were advanced.%植物化感作用体现了植物个体及群体之间生化相克相生的关系,它广泛地存在于农业生态系统之中,与植物对光、水分、养分和空间的竞争一起构成植物间以及与其他生物间的相瓦作用.文章在综合介绍植物化感作用研究背景、化感物质的种类、释放方式以及作用形式的基础上,系统地综述了近年来国内外有关植物化感现象的最新研究进展,并对植物化感作

  16. Allelopathy Comparison of Eupatorium adenophroum and Artemisia scoparia Rhizosphere Soil on Rape Seed%紫茎泽兰和黄蒿根际土壤对油菜化感作用的比较研究

    Institute of Scientific and Technical Information of China (English)

    谭永钦; 李丽; 胡兵; 熊程; 王永模

    2011-01-01

    紫茎泽兰(Eupatorium adenophroum)是一种典型的恶性入侵杂草,在入侵地可造成严重的生态破坏.前人研究发现紫茎泽兰根际分泌物对周围植物生长存在化感作用,并认为化感作用是其入侵扩张的主要原因之一.为了确认化感作用在紫茎泽兰入侵中的重要性,本研究首次将紫茎泽兰和本地杂草黄蒿(Artemisia scoparia)的根际土壤对油菜(Brassica napus)的化感作用进行了比较研究.结果表明,两种植物根际土壤对油菜种子萌发均有较强抑制作用,黄蒿根际土壤发芽抑制率(46.7%)极显著高于紫茎泽兰土壤(20.0%)(P<0.01);试验第4天测定结果显示,紫茎泽兰和黄蒿对油菜根长和芽长的抑制作用极显著(P<0.01),而紫茎泽兰和黄蒿的根长抑制作用差异不显著(P>0.05).以上结果说明紫茎泽兰和黄蒿均存在化感作用,仅用化感作用不足以解释紫茎泽兰入侵扩张力强的原因.%Eupatoriwn adenophroum is a notorious invasive weed, which leads to serious economic and biodiversity loss in invasion areas. Previous studies found that the exudation around the rhizosphere of E. Adenophroum can strongly inhibit the growth of neighboring plants, which is called allelopathy. Allelopathy is considered as one of the important reasons of strong expansion and invasion of this weed. To confirm the importance of allelopathy, we compared the allelopathy of rhizosphere exudation of E. Adenophroum with that of Artemisia scoparia on rape seed Brassica napus for the first time. The results showed that both E. Adenophroum and A. Scoparia significantly inhibited sprout of B. Napus, and inhibition rate of A. Scoparia (46. 7% ) is significantly higher than that of E. Adenophroum (20. 0% ) ( P 0. 05 ). Results above may indicate allelopathy is not an important reason for the strong invasion and expanding ability of E. Adenophroum.

  17. Research on the Allelopathy of Camellia sinensis in Yibin on the Seed Germination of Two Kinds of Crops%宜宾茶对2种农作物种子萌发的化感作用研究

    Institute of Scientific and Technical Information of China (English)

    邓骛远

    2012-01-01

    [ Objective] The aim was to research the allelopathy of tea plant (Camellia sinensis(L. )O. Kuntze) in Yibin on the seed germination of two kinds of crops. [Method] The bioassay method was used to study the allelopathy of tea plant on the seed germination of maize {Zea mays L. ) and fava bean(Vicia faba Linn. ). [Result] The allelopathy has a close relation to the species of acceptor plant, supporter organs and extract concentration. The general trend of the synthesis effect is as follows: maize > fava bean, leaf > root > stem. Within the range of extract concentration in this experiment, the allelopathy effect of aqueous extract of root, stem and leaf at the concentration of 0. 100 g/ml is the strongest. The root, stem and leaf of tea plant inhibit maize seed germination; but for fava bean, only the stem promotes its seed germination, the root and leaf inhibit it. The index of allelopathic effect of germination speed is greater than the rate of final germination, it indicates that the allelopathy of tea plant mainly extend or shorten the germinating period of maize or fava bean. [Conclusion] The soil near the tea garden is not conducive to growing maize and faba bean.%[目的]研究宜宾茶树(Camellia sinensis L.)对2种农作物种子萌发的化感作用.[方法]采用生物测定法研究宜宾茶树根、茎、叶水浸提液对玉米( Zea mays L.)和蚕豆(Vicia faba Linn.)种子萌发的化感作用.[结果]茶树的化感作用和受体植物种类、供体植物器官以及浸提液浓度有关.化感效应总趋势为玉米>蚕豆,叶>根>茎.在实验设计的浸提液浓度范围内,0.100 g/ml的根、茎、叶浸提液对2种种子萌发的化感作用最强.茶树根、茎、叶对玉米种子萌发均表现为化感抑制作用;对蚕豆而言,仅茶树茎对其种子的萌发表现为促进作用,而根、叶为化感抑制作用.对种子发芽速率的化感效应敏感指数远大于最终发芽率的敏感指数,表明茶树的化感作

  18. Allelopathy of winter cover straws on the initial maize growthAlelopatia de palhadas de coberturas de inverno sobre o crescimento inicial de milho

    Directory of Open Access Journals (Sweden)

    Jaqueline Senen

    2011-07-01

    Full Text Available In agricultural crops is common planting the main crop on the remains of straw harvesting the crop earlier due to no-tillage system. The straw remaining in the soil can exert positive or negative influence on the main crop through the release of organic compounds that carry allelopathy on plants of the subsequent growing. This experiment consisted of mixing and blending of different types of turnip (Brassica rapa L., oats (Avena sativa L., crambe (Crambe abyssinica Hochst. Ex RE Fries, Safflower (Carthamus tinctorius L. and rapeseed (Brassica napus L . var in soil and placed in plastic trays where they planted the seeds of maize. The experimental design was completely randomized design with six treatments and three repetições. As ratings were: emergence, rate of emergence, shoot length, root length, root dry weight, dry weight of shoots. The cover crops canola and safflower showed a positive effect, as crambe, turnips and oats had a negative effect on initial growth of maize seedlings, are not suitable for cover crop to maize sowing.Nas lavouras agrícolas é comum o cultivo da cultura principal sobre os restos de palha da colheita do cultivo anterior em decorrência do sistema de plantio direto. A palhada remanescente no solo pode exercer influência positiva ou negativa sobre a cultura principal pela liberação de compostos orgânicos que exercem alelopatia sobre as plantas da cultura subsequente. Este experimento constou da mistura e homogeneização das palhas de nabo (Brassica rapa L., aveia (Avena sativa L., crambe (Crambe abyssinica Hochst. ex R. E. Fries, cartamo (Carthamus tinctorius L. e canola (Brassica napus L.var no solo, que foi colocado em bandejas plásticas onde semeou-se o milho. O delineamento experimental foi inteiramente casualizados com seis tratamentos e três repetições. As características analizadas foram: emergência, índice de velocidade de emergência, comprimento de parte aérea, comprimento de raiz, massa

  19. Effect of Cinnamomum longepaniculatum allelopathy on the mitosis of Vicia faba root tip cells%宜宾油樟的化感作用对蚕豆根尖细胞有丝分裂的影响

    Institute of Scientific and Technical Information of China (English)

    邓骛远; 罗通; 郑田喜

    2011-01-01

    利用油樟水浸提液作用蚕豆根尖研究了油樟化感作用对蚕豆根尖细胞有丝分裂的影响.结果表明:油樟对蚕豆根尖细胞有丝分裂的化感作用和浸提液浓度、作用时间有密切关系.在实验设计的范围内,随油樟水浸提液浓度的加大,蚕豆根尖细胞有丝分裂指数显著减小,而细胞微核率显著提高;油樟浸提液作用48 h时,对蚕豆根尖细胞有丝分裂的化感作用最强;油樟水浸提液诱导蚕豆根尖细胞产生染色体断片和滞后染色体等多种畸变染色体,并使有丝分裂各时期的分裂相减少.说明油樟化感物质抑制了细胞的有丝分裂,促进微核的产生,从而影响蚕豆根尖的生长和细胞的遗传稳定性.%The effect of Youzhang [Cinnamomum longepaniculatum (Gamble), N.Chan]allelopathy on the mitosis of Vicia faba root tip cells was studied with Youzhang water extracts acting Vicia faba root tips.The result shows the allelopathy has a close relation to the extract concentration and treating time.Within designed range of the experiment, the mitosis index of Vicia faba root tip cells decreases obviously, and the micronucleus frequency rises remarkably along with the increase of Youzhang extract concentrations.When acting time comes to 48 hours, the allelopathy of Youzhang extracts on the mitosis of Vicia faba root tip cells is the strongest.Youzhang water extracts induce a variety of aberrant chromosomes, such as chromosome fregments and delaying chromosomes, and inhibit mitosis different phases.It is implied that Youzhang's allelopthy matter inhibits cell mitosis, and promotes micronucleus generation of cells, and finally affects the growth of Vicia faba root tips and the genetic stability of cells.

  20. IDENTIFITION AND STUDY ON ALLELOPATHY OF SOYBEAN ROOT EXUDATES%大豆根分泌物的鉴定及其化感作用的初步研究

    Institute of Scientific and Technical Information of China (English)

    韩丽梅; 李国权

    2000-01-01

    采用GC-MS分析法,鉴定了由水培试验方法获得的2周、8周大豆根分泌物的二氯甲烷提取物,并对其化感作用进行了初步研究。结果表明:能被二氯甲烷提取出来的根分泌物有有机酸类、醇类、酯类、酮类、醛类、酚类、苯类、烃类等有机化合物,其中包含一些资料报道过的化感物质。与对照比较,2周、8周大豆根分泌物对大豆种子萌发、8周根分泌物对胚根生长未表现出显著抑制作用,但2周根分泌物对胚根生长却表现出极显著的化感抑制作用。上述结果表明,大豆根分泌物中存在化感物质,2周与8周大豆根分泌物的种类和数量有所不同。本文还探讨了大豆根分泌物的化感作用及大豆根分泌物与大豆连作障碍的关系等问题。%Compounds extracted with dichloromethane from soybean rootexudates for two weeks, eight weeks in water-culture were identified and allelopathy were studied by GC-MS analysis. The results showed that: The soybean root exudates extracted with dichloromethane included organic acide, alcohol, ester, acetone, aldehyde, phenol, pheyl, hydrocarbon and so on. Many of which were reported as allelochemicale. Contrast with control, the influence of the soybean root exudates for two weeks, eight weeks on the germination of soybean seeds, for eight weeks on radicle growth did not show significant allelopathy inhibition. But the allelopathy of the soybean root exudates for two weeks on soybean radicle growth showed significant inhibition. The results showed that the allelochemicals exist in the soybean root exudates. The varieties and quantities of soypean root exudates for two weeks are different with those for eight weeks. In addition, the alleleopathy of soybean root exudates and the relationship between soybean root exudates and barrier on soybean continuous and alternate cropping were discussed.

  1. 大蒜根系分泌物化感作用及化感物质的比较%Comparative analysis of allelopathy and allelochemicals of the root exudates in garlic

    Institute of Scientific and Technical Information of China (English)

    周艳丽; 程智慧

    2012-01-01

    【目的】利用生物测定和GC-MS分析方法,研究大蒜根系分泌物的化感作用及化感物质。【方法】采用琼脂培和砂培2种栽培方式收集大蒜根系分泌物,分别采用乙醚、乙酸乙酯、三氯甲烷和正丁醇4种有机溶剂进行萃取分离,对各有机溶剂萃取液进行萝卜种子发芽试验,确定出强化感作用组分,并对其成分进行GC-MS分析。【结果】各有机溶剂萃取液的化感作用强弱顺序依次为:乙酸乙酯萃取液〉三氯甲烷萃取液〉正丁醇和乙醚萃取液,初步确定大蒜根系分泌物中的化感物质为2,6-二异丙基苯酚、2,6-二叔丁基对甲酚和二烯丙基二硫醚。【结论】2种栽培方式收集的大蒜根系分泌物的乙酸乙酯组分中的成分相似,但在含量上差异较大,表现为砂培〉琼脂培。%【Objective】 The allelopathy and major allelochemicals in root exudates of garlic were studied by bioassay and GC-MS methods.【Method】 The root exudates of garlic were collected from agar culture and sand culture in this experiment,and were extracted by ethyl ether,ethyl acetate,chloroform and n-butanol.【Result】 The results showed that allelopathy of ethyl acetate component was the strongest,followed by chloroform component,the allelopathy of ethyl ether component and n-butanol component.The component of ethyl acetate was analyzed by GC-MS,and the main allelochemicals were identified as 2,6-bis(1-methylethyl)-phenol,butylated hydroxytoluene and diallyl disulphide.【Conclusion】 The allelochemicals were similar in ethyl acetate fraction of two cultivation forms,but the quantity was different,and the varieties and quantities of allelochemicals in sand culture were higher than agar culture.

  2. Positive Periodic Solutions of Two-Specics Impulsive Systems with Time Delays in Plankton Allelopathy%具时滞和脉冲的植化相克系统周期正解

    Institute of Scientific and Technical Information of China (English)

    汪东树; 王全义

    2012-01-01

    考虑一类具时滞和脉冲的两种群周期浮游生物植化相克系统,利用一些分析技巧和重合度理论,并巧妙构造一个同伦变换,得到该系统存在周期正解新结果,推广并改进了相关结果.%In this paper, two-species nonautonomous impulsive systems that arise in plankton allelopathy with time delays and periodic environmental factors are considered. By means of coincidence degree theory and some analysis techniques, we obtain some new results on the existence of positive periodic solutions to the system. Our results generalize and improve the related results.

  3. 入侵植物马缨丹对4种农作物的化感作用%Allelopathy of Invasive Plant Lantana camara on four Receiver Plants

    Institute of Scientific and Technical Information of China (English)

    卢向荣; 谭忠奇; 林益明; 柴纬明; 周海超

    2013-01-01

    Lantana camara , Verbenaceae family, is one of the invasive alien plants. Previous study about the allelopathy of L. camara mainly focused on exudates from stem and leaf,however,few study analysed the allelopathy of root exudates. At present,with the increasing of L. camara invasion expands scales,the plant has been expanded into farmland gradually. The aims of this study is to determine the allelopathy of different concentrations of water extracts from L. camara leaf and root on the germination and seedling growth of Vigna radiata ,Brassica campestris , Triticum aestivum and Oryza sativa. Different parts and concentrations of water extracts from L. camara had different allelopathic effects on four receiver plants. Except the lowest concentration (2 mg/mL) had slight facilitation effects,other higher concentrations (20,50,100,200 mg/mL)showed significant inhibition effects and the inhibition increased with concentrations. The sensitivity of water extracts from L. camara was different among four tested species,B. campestris was sensitive to allelopathy of L. camara,while O. sativa was not. This study gave theoretical support for improving the competitiveness of crops aroud L. camara,and also provide a scientific foundation for control of current invasions and prevention of future invasions.%马缨丹(Lantana camara)是马鞭草科中一种入侵性极强的外来植物,为了明确马缨丹对入侵地农作物的化感作用,研究了不同浓度马缨丹叶片及根系水浸液对绿豆(Vigna radiata)、油菜(Brassica campestris)、小麦(Triticum aestivum)和水稻(Oryza sativa)种子萌发和幼苗生长的影响.结果表明,马缨丹不同部位及不同浓度水浸液对4种农作物化感效应不同,马缨丹水浸液对4种农作物的种子萌发及幼苗生长具有低质量浓度(2 mg/mL)轻微促进、中高质量浓度(20,50,100和200 mg/mL)较强烈的抑制作用,且随着水浸液浓度的升高其抑制效应不断增强.不同作物对马缨丹

  4. 不同品系小麦根系分泌物对黄瓜化感作用的初步研究%Primary Studies about Root Exudates from Different Wheat Cultivars on Cucumber Allelopathy

    Institute of Scientific and Technical Information of China (English)

    马亚飞; 杨平; 吴凤芝

    2011-01-01

    以黑龙江省40个小麦品系为供体,以黄瓜品种津优1号为受体,采用培养皿滤纸生物测试法,初步研究了不同品系小麦根系分泌物对黄瓜幼苗的化感作用.结果表明:不同品系小麦根系分泌物对黄瓜种子发芽率、幼苗根长、胚轴长及幼苗鲜质量的影响存在差异.由综合效应(SE)可以看出,龙辐04-0348对黄瓜幼苗的化感促进作用最强,龙辐17化感抑制作用最强,综合化感效应分别为-15.37%和7.76%.%Taking 40 wheat cultivars in Heilongjiang Province as donor and 'Jinyou No.l' cucumber ( Cucumis sativus L. ) as accepter, allelopathy of root exudates from different wheat cultivars on cucumber seedlings were investigated in petri dish experiment. Results showed that different wheat cultivars had different allelopathy on cucumber germination rate, radicle length, radicle and shoot fresh weight. Judging from synthesize effect (SE) value, 'Longfu 04-0348' had the most significant stimulatory effect, and ‘Longfu 17' had the most significant inhibitory effect, their SE values were -15.37 % and 7.76 %,respectively.

  5. 陆生植物化感作用抑制藻类生长的研究进展%Review on Inhibition of Terrestrial Plant Allelopathy of Algae Growth

    Institute of Scientific and Technical Information of China (English)

    边归国

    2012-01-01

    Research of the plant allelopathy inhibition of algae growth is focused on aquatic plants, yet there are few researches on terrestrial plant. Terrestrial plants have the features of widely distributed, large biomass, easy cultivation, easy harvesting and easy processing. Many herbaceous and woody plants are rich in allelochemicals, which have prospect in the algae blooms inhibition and emergency response of the blooms. According to domestic and abroad research reports about terrestrial plant inhibition of algae growth, with sorting of herbaceous and woody, as well as classification of different plants, 15 families and 26Kinds of land plants allelopathy were evaluated.%目前关于植物化感抑制藻类生长的研究主要集中于水生植物,陆生植物对藻类化感作用的研究相对较少.陆生植物具有分布广泛、生物量大、便于培植、容易收割、加工方便等特点,许多草本植物和木本植物体内含有丰富的化感物质,在抑制水中藻类生长和应急处置水华等方面具有良好的应用前景.根据国内外近年来对陆生植物关于抑制藻类生长的研究报道,按草本和木本分类,并以植物的科划分,较全面地评述了15科26种陆生植物化感作用的研究进展.

  6. Allelopathy in pigweed (a review)

    OpenAIRE

    Pedro Luis da Costa Aguiar Alves; Leonardo Bianco de Carvalho; Marcelo Claro Souza; Paulo Roberto Fidelis Giancotti

    2011-01-01

    Amaranthus spp. are plants with proven allelopathic potential. The release of allelochemicals from Amaranthus spp. in the environment can influence seed germination, photosynthesis rate, reduce growth and, consequently, the productivity of various plant species. Among the species with allelopathic potential are Amaranthus blitoides, Amaranthus gracilis, Amaranthus hybridus, Amaranthus palmeri, Amaranthus retroflexus, Amaranthus spinosus and Amaranthus viridis, with A. retroflexus being the mo...

  7. 红花酢浆草提取液对3种草花种子萌发的影响%Allelopathy Effects of Oxalis corymbosa on Seed Germination of Three Herbaceous Flowers

    Institute of Scientific and Technical Information of China (English)

    章玉平; 彭燕燕

    2011-01-01

    In order to study the allelopathy effect on seed germination and seedling growth of the aqueous extracts from leaves and leafstalks of Oxalis corymbosa, probing the invasive mechanism of alien species, the aqueous extracts of O. Corymbosa were used as the test material in this paper. Its purpose was to study the influence of the aqueous extracts of 0. Corymbosa to Tagetes patula, Calendula officinalis and Celosia cristata three herbaceous flowers seed germination and seedling growth. The concentration of the aqueous extracts from leaves and leafstalks of 0. Corymbosa was 0 (CK), 0.625%, 1.25%, 2.5%. The results showed that sensitivity to the aqueous leaf extract of O. Corymbosa differed among the three species. Concentration at 0.625% of the O. Corymbosa aqueous extracts from leaves and leafstalks promoted the germination and seedling growth of Tagetes patula, however, concentration at 1.25%, 2.5% inhibited the germination and seedling growth of Tagetes patula. Concentration at 0.625%, 1.25%, 2.5% of the O. Corymbosa aqueous extracts from leaves and leafstalks inhibited the germination and seedling growth of Calendula officinalis and Celosia cristata, but the inhibition of concentration gradient was not remarkable. The test showed the allelopathy of O. Corymbosa to Tagetes patula was stronger, the allelopathy to Calendula officinalis and Celosia cristata was weaker.%为研究红花酢浆草叶片和叶柄水提取液对3种草花种子萌发的影响,探明外来物种入侵的机制,以红花酢浆草叶片和叶柄的不同浓度水提取液为材料,研究不同浓度(0.625%、1.25%、2.5%)的水提取液浸种对金盏菊、羽状鸡冠花、孔雀草种子萌发的影响.结果表明:不同草花种子对红花酢浆草水提取液的敏感程度不同.0.625%的红花酢浆草水提取液对金盏菊种子萌发具有促进作用,1.25%、2.5%的水提取液对其具有抑制作用.0.625%、1.25%和2.5%的红花酢浆草水提取液对孔雀

  8. Isolation and Identification of Marinobacter adhaerens HY-3 and Its Allelopathy on Skeletonema costatum%海洋细菌Marinobacter adhaerens HY-3分离鉴定及对中肋骨条藻的化感作用

    Institute of Scientific and Technical Information of China (English)

    王洪斌; 陈文慧; 李信书; 李士虎; 阎斌伦

    2013-01-01

    The allelopathy between bacteria and algae is a very complicated physical and ecological phenomenon. A marine bacterium was isolated from the water of a shrimp and crab mix-culturing pond. By 16S rRNA analysis, it was identified as Marinobacter adhaerens HY-3. Skeletonema costatum, a common dominant species of red-tide microorganism in China, was chosen as the other research object. The allelopathic effect of Marinobacter adhaerens HY- 3 on S. costatum was studied. Using the growth mass of Skeletonema costatum and the content of chlorophyll a as the parameters, the effects of HY- 3 on the growth and photosynthesis of Skeletonema costatum were studied after co-cultivation and addition of extracellular metabolites of HY-3. The results showed that the growth of S. costatum was inhibited when the concentration of the strain HY-3 was above 10 , and the growth mass of the 10 , 10 and 108 HY-3 group was 70% , 23% and 22% of the control group respectively on the 10th day, with the content of chlorophyll being 88% , 62% and 60% of the control group, respectively. Therefore, the suppression increased with increasing concentration of HY- 3. However, addition of extracellular metabolites of HY-3 had no effect on the growth of S. costatum. Conclusions; M. adhaerens HY-3 had certain allelopathy on S. costatum and affected its growth and photosynthesis. Moreover, interaction between M. adhaerens HY-3 and S. costatum was achieved by their direct contact and the extracellular metabolites did not contain allelopathy factors.%菌藻化感作用是一种极其复杂的生理、生态学现象.从虾蟹混养池分离得到1株海洋细菌,经16S rRNA序列比对确定为Marinobacter adhaerens HY-3,选择我国常见赤潮优势种中肋骨条藻(Skeletonema costatum)作为对象,研究海洋细菌与其种间化感效应,利用共培养和添加细菌胞外代谢物,以S.costatum生长量及叶绿素a含量为参数,研究细菌对S.costatum生长及光合作用的

  9. Alelopatia de duas espécies de braquiária em sementes de três espécies de estilosantes Allelopathy of two brachiaria species in seeds of three species of stylosanthes

    Directory of Open Access Journals (Sweden)

    Adriana Paula D'Agostini Contreiras Rodrigues

    2012-10-01

    Full Text Available A alelopatia é muito comum em gramíneas como a Brachiaria brizantha e B. decumbens, podendo representar um problema em pastagens consorciadas com Stylosanthes, já que, nessa situação, a perpetuação da leguminosa depende da ressemeadura natural. Apesar da grande quantidade de sementes de estilosantes produzidas anualmente, nessas pastagens consorciadas, observa-se, em campo, pequena quantidade de plantas jovens, o que pode ser atribuído a um possível efeito alelopático da gramínea. Considerando a importância da alelopatia no consórcio de braquiárias com estilosantes, testou-se o potencial alelopático de extratos de Brachiaria brizantha e B. decumbens na germinação de sementes de três espécies de estilosantes. Verificou-se que há efeito alelopático negativo de B. brizantha e B. decumbens na germinação de sementes de Stylosanthes guianensis e somente de B. decumbens na germinação de S. capitata; há efeito alelopático positivo de B. brizantha nas sementes de S. macrocephala; não há efeito alelopático de B. brizantha na germinação de sementes de S. capitata e nem de B. decumbens em S. macrocephala.The allelopathy is very common in grasses such as Brachiaria brizantha and Brachiaria decumbens, could represent a problem in pastures consortium with Stylosantes since, in this situation, the perpetuation of the legume dependent natural reseed. In spite of the great amount of estilosantes seed produced annually in those pastures consortium, it is observed in field, small amount of young plants, which can be attributed to a possible allelopathic effect of the grass. Considering the importance of allelopathy in the consortium of Brachiaria with estilosantes, we tested the allelopathic potential of extracts of B. brizantha and B. decumbens on seed germination of three estilosantes species. It was found that there allelopathic negative effect of B. brizantha and B. decumbens on seed germination of Stylosanthes guianensis and

  10. Allelopathy of Water Extracts from Seeds of Althaes rosea on Watermelon and Chinese Wolfbeery%蜀葵种子水浸液对西瓜和枸杞的化感作用

    Institute of Scientific and Technical Information of China (English)

    张益民; 薛泽

    2012-01-01

    Allelopathy of water extracts from seeds of Althaea rosea on watermelon and Chinese wolfberry were examined, with the objective of providing the reference for the theoretical study of allelopathy. By using the techniques of laboratory bioassay, the effects of water extracts from seeds of Althaea rosea on seeds germination and seedlings growth of watermelon and Chinese wolfberry were studied. The results showed that treated with different concentrations water extracts from seeds of Althaea rosea on seeds germination and seedlings growth of watermelon could be inhibited, and on height, fresh weigh of Chinese wolfberry could be promoted; when the concentration of water extracts was 0.005 g/mL, 0.010 g/mL, the water extracts from seeds of Althaea rosea exhibited significant promotion effects on seeds germination and seedlings growth of Chinese wolfberry, and when the concentration of water extracts was 0.020 g/mL, the water extracts from seeds of Althaea rosea exhibited significant inhibition effects on germination of seed, length of main root and fresh weight of root of Chinese wolfberry.%研究蜀葵种子水浸液对西瓜和枸杞的化感作用,为植物化感作用的理论研究提供参考.采用生物测定法,用不同浓度的蜀葵种子水浸液处理西瓜、枸杞的种子和幼苗,研究其化感作用.结果表明:(1)不同浓度的蜀葵种子水浸液对西瓜种子萌发和幼苗生长均有不同程度的抑制作用,对枸杞幼苗的苗高、鲜重有促进作用;(2)当蜀葵种子水浸液浓度为0.005 g/mL、0.010 g/mL时对枸杞种子萌发和幼苗生长表现为化感促进作用,浓度为0.020 g/mL时对枸杞种子的发芽率、幼苗根长、根鲜重表现为化感抑制作用.综上,蜀葵种子水浸液可抑制西瓜种子的萌发和幼苗的生长,对枸杞幼苗的苗高、鲜重的增加有促进作用.

  11. 麦冬水提液对莴苣等3种植物化感作用的初步研究%Preliminary Study on the Allelopathy of Ophiopogon japonicus Extracts on Lactuca sativa and 2 Other Plants

    Institute of Scientific and Technical Information of China (English)

    徐莹梅; 田胜尼

    2011-01-01

    In this paper the experiments were carried out to study the allelopathy of Ophiopogon japonicus extracts on Lactuca sativa,Cucumis sativus and Raphanus sativus.The results showed that the water extracts of underground and aboveground parts of Ophiopogon japonicus had significant inhibiting effects on the seed germination rate of Cucumis sativus and Raphanus sativus,but no obvious inhibiting effects on that of Lactuca sativa.The extracts also had inhibiting effects on the growth of the main roots of the tested plants,while accelerating the stem growth of Cucumis sativus.%通过麦冬水提液对莴苣、黄瓜、萝卜3种不同植物的化感作用试验研究,结果表明:麦冬地下和地上部分水提液对供试种子黄瓜、萝卜的萌发表现显著的抑制作用,但对莴苣的抑制作用不明显;麦冬水提液对供试植物主根的生长产生抑制作用,而对黄瓜茎的生长表现促进作用。

  12. Preliminary Isolation and Identification of Allelopathy from the Rhizosphere Soil of Panax notoginseng(Buck)F.H.Chen%三七根际土壤化感物质的初步分离鉴定

    Institute of Scientific and Technical Information of China (English)

    周家明; 张文斌; 杨建忠; 崔秀明; 曾鸿超; 朱琳

    2012-01-01

    Objective To extract and isolate allelopathy from the rhizosphere soil of Panax notoginseng (Buck) F. H. Chen. Methods Modern technology of extraction and separation were used, and the extracts were acid, neutral, alkaline. Results 306 samples were analysed by TLC. Conclusion 7 kinds compound such as Beta-sitosterol, Ferulate, Rhl, Rh4, daucosterol, Rgl, and Rl were identified from the extract of the rhizosphere soil of Panax notoginseng (Buck) F. H. Chen.%目的对不同地点的四批次连作三七障碍土壤分析.方法 用现代技术工艺进行提取分离,提取液分为酸性、中性、碱性组分.结果 用硅胶薄层板(TLC)点样分析样品306个.结论经分析鉴定,提取液中含有7个化合物,分别为(1)β—谷甾醇、(2)阿魏酸、(3)Rh1、(4)Rh4、(5)胡萝卜苷、(6)Rg1、(7)R1.

  13. Allelopathy and Chemical Components of Extract from Green Peel of Juglans mandshurica Maxim.%核桃楸外果皮提取物的化感作用及成分分析

    Institute of Scientific and Technical Information of China (English)

    孙墨珑; 宋湛谦; 方桂珍

    2008-01-01

    采用常规提取法浸提核桃楸外果皮的化感作用成分.研究结果表明,核桃楸外果皮乙醇提取物和乙酸乙酯萃取相对3种受体植物青菜、萝卜和紫花苜蓿具有化感作用(抑制萌发和抑制生长作用).化感作用随提取物浓度增大而增大.采用GC-MS分析核桃楸外果皮乙醇提取物中乙酸乙酯萃取相的化学组成和相对含量.分析结果表明,核桃楸外果皮乙醇提取物中乙酸乙酯萃取相的主要化学成分为5-羟基-1,4-萘醌(胡桃醌),GC含量31.20%;正十六酸,GC含量9.99%;7-甲氧基-1-四氢萘酮,GC含量7.99%;1,5-萘二酚,GC含量7.15%;2,6-二甲氧基苯酚,GC含量4.36%;4-丁氧基苯醛;GC含量3.23%;5-羟甲基-2-呋喃醛,GC含量2.96%;二聚1,3-二羟基丙酮,GC含量2.94%;丙三醇,GC含量2.77%;1(3H)-异苯并呋喃酮,GC含量2.57%.%The extract from green peel of Juglans mandshurica Maxim.was extracted by common method for studying its allelopathy and analyzing the chemical components.Results showed that the alcohol extract and the ethyl acetate part of alcohol extract(separated with ethyl acetate from alcohol extract)exhibit allelopathy(inhibiting seed germination and seedling growth)on Brasica chinesis,Raphanus sativus and Medicago sativa.Their effects were extract-concentration dependent,increasing with the increase of extract concentration.The chemical components in the ethyl acetate part of alcohol extract from green peel of J.mandshurica were analyzed by GC-MS.Results showed that the main chemical components and their GC contents in the ethyl acetate part of alcohol extract were:5-hydroxy-1,4-naphthalenedione(juglone)31.20%,n-hexadecanoic acid 9.99%,7-methoxy-1-tetralone 7.99%,1,5-naphthalenediol 7.15%,2,6-dimethoxy-phenol 4.36%,4-butoxy benzaldehyde 3.23%,5-(hydroxymethyl)-2-furancarboxaldehyde 2.96%,1,3-dihydroxyacetone dimmer2.94%,glycerin 2.775,1(3H)-isobenzofuranone 2.57%.Twenty-four compounds in the ethyl acetate part of alcohol extract have been

  14. The effect of allelopathy on the competition and succession between Skeletonema costatum and Prorocentrum donghaiense%化感作用对中肋骨条藻与东海原甲藻竞争演替的影响

    Institute of Scientific and Technical Information of China (English)

    王江涛; 李慧; 曹婧; 张议文

    2012-01-01

    为了检验化感作用对赤潮藻类生长和竞争的影响,对中肋骨条藻滤液进行了培养实验,结果显示中肋骨条藻滤液对其自身的生长呈现出化感抑制现象,而且抑制作用在磷限制条件下尤为显著.自化感作用的程度与藻的生长阶段有关,指数期滤液对中肋骨条藻的抑制作用比衰亡期滤液略强.不同滤液添加比例实验进一步验证了中肋骨条藻自化感作用的存在.降解实验表明在某些机制的作用下,化感物质会随时间而发生降解.在所有的滤液培养实验中,中肋骨条藻对东海原甲藻的生长没有明显影响,这可能是由于东海原甲藻对滤液中的化学物质有较强的耐受能力.中肋骨条藻滤液的共培养实验结果显示,中肋骨条藻与东海原甲藻表现出演替现象,东海原甲藻最终获得竞争优势.实验结果表明化感作用可能会影响中肋骨条藻和东海原甲藻的竞争演替.%Culture filtrates of Skeletonema costatum were tested to verify the effects of allelopathy on the growth of algae. S. Costatum growth was inhibited, especially in P limiting cultures. The filtrates of S. Costatum in exponential phase exhibited significantly inhibitory effect on the growth of its own compared with the controls, which was stronger than that of declining phase filtrates, hence, allelopathic effect was connected with the growth phase of algae. The filtrates with different ratios showed different inhibitory degrees to S. Costatum itself, and the ratio was higher the inhibition was stronger. In degradation experiments, the dramatic decrease of inhibitory effect on S. Costatum was observed. A possible explanation for this might be that allelopathic compounds in S. Costatum cultures could be degraded. In addition, during all filtrate experiments, the growth of P. Donghaiense was not affected, which might because of the tolerance of P. Donghaiense to these allelochemicals in S. Costatum filtrates. Furthermore

  15. Studies on the Allelopathy and GAP Management of Andrographis paniculata (Burm.f.) Nees%穿心莲化感作用与GAP栽培规范的研究

    Institute of Scientific and Technical Information of China (English)

    曾令杰; 刘意; 褚晨亮; 何洋

    2011-01-01

    目的 研究穿心莲的化感作用,为GAP栽培管理提供依据.方法 以表面皿培养法试验穿心莲根际土壤浸提液及穿心莲内酯对照品溶液对穿心莲种子及三叶鬼针草种子萌发的抑制作用:以HPLC法对穿心莲根际土壤浸提液进行了分析鉴定.结果 穿心莲根际土壤浸提液及穿心莲内酯对照品溶液均能显著抑制三叶鬼针草和穿心莲种子的萌发,其抑制作用随着浓度的增大而增强;结果表明,穿心莲内酯是其根际土壤浸提液中的一主要成分.结论 穿心莲在其生长过程中释放了化感物质进入了其根际土壤,对穿心莲和其他植物产生化感作用,穿心莲内酯为其中的主要化感物质之一.%Objective To investigate allelopathy of Andrographis paniculata (Burm.f.) Nees for its GAP management.Methods With watch glass culture, the inhibitory effects of andrographlide and the rhizosphere extract of Andrographis paniculata on seed germination of the herb itself and Bidens pilosa were conducted, and with HPLC method, the main constituents of the rhizosphere extract were analysed.Results The results showed that both of andrographlide and the rhizosphere extract had significant inhibitory effects on the germinations of Bidens pilosa seeds and itself; the effects strengthened with increasing of their concentrations.Andrographlide is one kind of main constituents in the rhizosphere extract indicated by HPLC analysis.Conclusion In the growth period, Andrographis paniculata release some alleochemicals into the soil, and andrographlide is one of the main allelochemical.

  16. 韭菜水提液对3种蔬菜种子的化感作用%Allelopathy Efects of Water Extract from Allium tuberosum on Vegetable Seeds

    Institute of Scientific and Technical Information of China (English)

    江贵波; 陈少雄; 江晓玲; 杨银娇; 聂耀龙; 蔡玉玲

    2014-01-01

    为解决生产实践中的连作障碍问题,以韭菜(Allium tuberosum Rottler.ex Spreng.)为供体,以其地上部分的水提液为化感物质,分别以白菜(Brassica chinensis L.)、油菜(Brassica campestris L.)和萝卜(Raphanus sativus L.)种子为受体,采用培养皿滤纸法进行化感试验,测定韭菜的茎叶水提液对油菜、白菜和萝卜幼苗的根长、苗高和鲜重的影响。结果表明:韭菜的地上部分的水提液对油菜、白菜和萝卜种子的萌发及其幼苗生长有明显的化感作用,且不同浓度水提液对蔬菜幼苗生长的影响存在差异,浓度为0.50 g/mL时抑制作用最强。%In order to solve the problem of continuous cropping barrier in production practice,taking Allium tuberosum as the donor,water extract of its aerial parts as allelochemicals and Brassica chinensis , Brassica campestris and Raphanus sativus seeds as the receptor,the effects of water extract of A.tuberosum on root length, seedling height and fresh weight of B.chinensis,B.campestris and R.sativus were studied by filter paper method with culture dish.Results:aerial part water extract had significant allelopathy on seed germination and seedling growth.Difference was observed among different concentrations of water extract (0.10 g/mL,0.25 g/mL,0.50 g/mL).0.5 g/mL had the strongest inhibition effect.Root length of rape seedling of 0.10 g/mL,0.25 g/mL and 0.50 g/mL treatments was reduced by 98.3%,100.0% and 100.0% respectively compared with the control.And that of B.chinensis seedling was reduced by 97.1%,100.0% and 100.0% respectively,and R.sativus was reduced by 72.5%,91.2% and 98.7% separately.

  17. Allelopathy of Aqueous Extract From Tomato Plants on Lettuce and Celegy Cabbage%番茄植株水浸提液对生菜和大白菜化感作用的研究

    Institute of Scientific and Technical Information of China (English)

    莫云容; 赵凯; 邓明华

    2015-01-01

    The study of allelopathy on tomato plants was made through measuring seedling growth of lettuce and celegy cabbage which were watered with the aqueous extract of tomato plants. The results lead to the following conclusions:① Tomato plants aqueous extract with lower concentration(0. 02 g/ml) re-strained length of seedling root and weight of celegy cabbage,while it prompted those of lettuce.②Toma-to plants aqueous extract with higher concentration ( 0 . 08 g/ml ) inhibited significantly both lettuce's length of seedling root as well as the weight of root and those of celegy cabbage;and the effects could be enhanced with the increase of the concentration.③Tomato plants aqueous extract in this concentration of 0. 04 g/ml,on one hand,which advanced seedling length of lettuces and root weight,root length and seed-ling length of celegy cabbages;on the other hand,which inhibited seedling length and root length of cele-gy cabbage.Tomato plant aqueous extract inhibited the ratio of seedling( root length)/( shoot length) of lettuce,while this turned to be helpful for Chinese cabbage. 5figs. ,1tab. ,11refs.%以生菜和大白菜两种蔬菜作物为受体,通过测定番茄植株水浸提液对两种蔬菜作物幼苗生长的影响,对番茄化感物质的作用进行了研究.结果表明:①低浓度(0.02 g/ml)的番茄水浸提液抑制大白菜幼苗的根长和根重;而促进生菜的根长和根重②高浓度(0.08 g/ml)的番茄水浸提液对生菜和大白菜幼苗根长、根重和苗长均表现为抑制作用.随着浓度的加大,抑制作用增强;③0.04 g/ml的番茄水浸提液对生菜幼苗苗长和大白菜的根重、根长/苗长有明显的促进作用,而对大白菜幼苗苗长、根长有抑制作用;榆番茄水浸提液对生菜幼苗根长/苗长比均表现为抑制作用、而对白菜的却表现为促进作用.图5,表1,参11.

  18. 葫芦瓜叶水浸液对蔬菜种子的化感作用%Allelopathy Effects of Water Extract from Leaves of Lagenaria siceraria var. hispida on Vegetable Seeds

    Institute of Scientific and Technical Information of China (English)

    张耀辉; 张丽华; 周娜娜; 陈忠荫; 吕能标

    2012-01-01

    以黄瓜、萝卜和番茄种子为受体材料,采用室内培养皿生物测定方法研究葫芦瓜叶水浸液的化感作用影响,为解决生产实践中的连作障碍问题提供科学依据。结果表明:10 g/L、50 g/L、90 g/L葫芦瓜叶水浸液对黄瓜、萝卜种子萌发率均具有一定的抑制作用,受体材料发芽率均比对照低;对番茄种子萌发率表现为低浓度促进、高浓度抑制;对黄瓜幼苗株高和鲜重都表现抑制作用,对萝卜和番茄幼苗株高和鲜重则表现为,在浓度90 g/L时为抑制作用,在浓度为10 g/L、50 g/L时为促进作用;对黄瓜和萝卜幼苗的根长都表现抑制作用,对番茄幼苗的根长在浓度为10 g/L时表现促进作用,在浓度为50 g/L、90 g/L时表现抑制作用。因此,在蔬菜栽培制度中,葫芦瓜可与番茄和萝卜进行合理的轮作与间套作,但不适宜与黄瓜进行轮作或间套作。%The allelopathy of water extract from the leaves of Lagenaria siceraria var.hispida on the seed germination of cucumber,radish and tomato were investigated by adopting indoor petri dish bioassay in order to provide the scientific basis of continuous cropping barrier solution in production practice.It is found that the water extract at the concentrations of 10,50 and 90 g/L had significant inhibiting effects on the seed germination rates of cucumber and radish.The germination rates of cucumber and radish were lower in the treatments with 10,50 and 90 g water extract/L than in the control with distilled water.The seed germination rate of tomato was increased at lower concentrations,and decreased at higher concentration.The plant height and the fresh weight of cucumber were inhibited at all the concentrations.The plant height and the fresh weight of radish and tomato were inhibited at 90 g/L,and stimulated at 10 g/L and 50 g/L.The water extract had significant inhibiting effects at all the concentrations on the roots of cucumber and radish.The roots of

  19. Chemical constituents and allelopathy of Tithonia diversifolia volatile oil%肿柄菊挥发油的化学成分分析及其化感作用

    Institute of Scientific and Technical Information of China (English)

    李晓霞; 沈奕德; 范志伟; 黄乔乔; 程汉亭; 刘丽珍

    2013-01-01

    采用水蒸气蒸馏法提取肿柄菊地上部分的挥发油,利用 GC-MS 技术对肿柄菊地上部分的挥发油进行分析,以假臭草、巴西含羞草、含羞草、蝶豆和鬼针草5种肿柄菊伴生植物为供试植物,用半密闭容器法对肿柄菊挥发油的化感效应进行生物测定.GC-MS分析结果显示,从肿柄菊挥发油中鉴定出50个化合物,占总出峰面积的94.79%,肿柄菊挥发油中主要含有α-蒎烯(63.81%)、柠檬烯(7.07%)、β-石竹烯(4.85%)、双环大香烯(2.95%)、香桧烯(2.78%)、斯巴醇(2.70%)等萜类和醇类化合物,占挥发油总量的94.15%,其中萜类化合物含量占总挥发油的86.01%.生测结果显示,肿柄菊挥发油对5种受试植物的种子萌发和幼苗生长均产生抑制作用,其中对巴西含羞草的抑制作用最为显著,而对含羞草和蝶豆影响较小.说明肿柄菊挥发油在其入侵扩散中发挥一定的化感作用.%Volatile oil was obtained from above ground part of Tithonia diversifolia by steam distillation method,and the main chemical components in the volatile oil were identified by gas chromatography-mass.Allelopathy of volatile oil from T.diversifolia on seed germination and seedling growth of 5 co-occuring plant species,Eupatorium catari-um,Mimosa diplotrich,Mimosa pudica,Clitoria ternatea,Bidens pilosa was studied in a semi-closed container.50 compounds were identified,accounting to 94.79% of the total detected constituents.The main components wereα-Pi-nene(63.81%),Limonene(7.07%),β-Caryophyllene(4.85%),Bicyclogermacrene(2.95%),Sabinene(2.78%),and Spathulenol(2.702%),which accounted for 94.15%of the total amount of the essential oil samples.Terpenes accoun-ted for 86.01% of the total.The bioassay test results demonstrated that volatile oil of T.diversifolia could inhibit the seed germination and growth of all tested plant.The inhibitory effects on Mimosa diplotricha was the largest

  20. Allelopathy in some spontaneous and cultivated species

    OpenAIRE

    A. S. Dias; Dias, L. S.

    1984-01-01

    Cucumber growth was inhibited by volatile and water soluble compounds occurring in leaves of Cistus salvifolius, Foeniculum vulgare, Myrtus communis and Rosmarinus officinalis but germination was never affected. R. officinalis shows some evidence of being the strongest inhibitor with both water soluble and volatile components while F. vulgare seems to contain more volatile-compounds. It is suggested that water soluble compounds are more inhibitory than volatiles and can play an important role...

  1. Allelopathy of the Secondary Separation Fraction of the Acetone Extract of the Root Material of Parsley on Fusarium Oxysporium f.sp.cucumeris%西芹根物质丙酮浸提液二次层析物对黄瓜枯萎病菌的化感作用

    Institute of Scientific and Technical Information of China (English)

    李蕾; 云兴福; 陈磊

    2012-01-01

    利用柱层析法及生长速率法研究了西芹根物质丙酮浸提液二次层析物对黄瓜枯萎病菌的化感作用.将西芹鲜根丙酮浸提液经一次层析后得到的最佳抑制流分进行二次分离,并对所得流分分别进行化感作用实验,得出流分1、2、4、5、6、7、9对黄瓜枯萎病菌的生长具有化感抑制作用,其中流分1和流分2的抑制效果最强,抑制率分别为79.31%和79.13%,与ck差异极显著(P<0.01);流分3、8、10对黄瓜枯萎病菌的生长具有化感促进作用.而将西芹根际土壤丙酮浸提液进行同样处理后,得出流分1、2、3、4、6、7、9、10对黄瓜枯萎病菌的生长具有化感抑制作用,其中流分1和流分3的抑制效果最强,抑制率分别为80.44%和81.28%,与对照ck差异极显著(P<0.01);流分5和流分8对黄瓜枯萎病菌的生长具有化感促进作用.随着时间的增加这种化感抑制或促进作用逐渐减弱.%Allelopathy of the secondary separation fraction of the acetone extract of the root and the rhizosperic soil of parsley on Fusarium oxysprium f. sp. cucumeriswas studied by column chro-matography and growth rate method. The best one of the first separation fraction of the acetone extract of the root of parsley was secondary separated and then the allelopathy of getting fraction was respectively tested. Fractions of No. 1, No. 2, No. 4, No. 5, No. 6, No. 7, and No. 9 inhibited the growth of Fusarium oxysporium f. sp. cucumeris, and the inhibitory rates of No. 1 and No. 2 were 79. 31 % and 79. 13% respectively,showing a stronger inhibitory effect than others and were highly significant different with ck(P<0. 01). Fractions of No. 3, No. 8, No. 10 promoted the growth of Fusarium oxysporium f. sp. cucumeris. Allelopathy of the rhizosperic soil of parsley was tested in the same way. The secondary separation fractions of No. 1, No. 2, No. 3, No. 4, No. 6, No. 7, No. 9, No. 10 inhibited the growth of Fusarium oxysporium

  2. Relationships among weed suppression effect, allelopathy and agronomic characteristics of Oryza longistaminata and related descendants%长雄野生稻及其后代抑草效果与化感潜力和农艺性状的关系

    Institute of Scientific and Technical Information of China (English)

    徐高峰; 申时才; 张付斗; 张玉华

    2014-01-01

    数等因素相关,在根际距离0~3 cm时,化感作用在苗龄30 d的强化感潜力水稻材料的抑草效应中起主要作用。%Rice allelopathy has been a new environmentally-safe way in paddy weed management that has met the needs of sustainable agriculture. This study explored the linkages among field weed suppression effects, allelopathy and agronomic characteristics of Oryza longistaminata and its related descendants. It critically exploited and utilized the important aspect of allelopathic genes of wild resources of rice germplasm. In the paper, wild rice (O. longistaminata) with allelopathic potential and‘RD23’ (O. sativa cultivar) without allelopathic potential and their F1 (RD23 × O. longistaminata) and F2 descendants were used in indoor assay and pot cultivation experiment in greenhouse to determine the effect of allelopathy and agronomic characters on weed suppression effects to barnyard grass. The results showed that weed suppression effects of strong allelopathic potential rice were significantly higher than those of rice with weak allelopathic and non-allelopathic potential at a rhizosphere distance of 0-3 cm under pot culture conditions. However, strong allelopathic potential rice not always had higher weed inhibition effects with increasing rhizosphere distance. When rhizosphere distance was greater than 3 cm, rice with strong tillering ability, fast growth and long upright stems had stronger weed inhibition effects under pot culture conditions irrespective of the allelopathic potential of the tested rice materials. Density control effect of rice seedlings aged 60 days was lower than those aged 30 days at rhizosphere distance of 0-3 cm. However, biomass control effect and plant height inhibition rate were greater for seedlings aged 60 days. With increase of rhizosphere distance, not significant difference was noted between seedling with two ages, except density control effect at rhizoshpere distance of 3-6 cm. Correlation analysis

  3. Allelopathy of Conyza canadensis on Seed Germination and Seedling Growth of Three Types of Weed%小飞蓬对三种杂草种子萌发和幼苗生长的化感作用

    Institute of Scientific and Technical Information of China (English)

    高源; 朱朝华; 李雪枫; 雷照鸣; 余树华

    2012-01-01

    and fresh weight compared with the control. When the concentration of ethyl acetate reached 2.0 mg/mL, the respond indexes of allelopathy (/?/) of the root length of E. Crusgalli and B. Pilosa were both -1.00; while the RI of the stem length was -0.97 and -0.78 respectively. The average germination rate of two seeds was 3.3% and 2.2% respectively. The butanol extract could inhibit the seed germination and seedling growth of three weeds, but its inhibition was weaker than the ethyl acetate extract. High concentration of the aqueous extract could effectively promote seedling growth of three weeds. It could be concluded that herbicidal active substances from C. Canadensis were probably existing in extracts of ethyl acetate.

  4. Allelopathy of the invasive plant Alternanthera philoxeroides to radish and lettuce%入侵植物空心莲子草对生菜和萝卜的化感效应

    Institute of Scientific and Technical Information of China (English)

    张志忠; 石秋香; 孙志浩; 蓝茂锋

    2013-01-01

    Alternanthera philoxeroides is a worldwide weed. After invasion of A. philoxeroides,the local ecosystem can be irreversibly damaged and agricultural production seriously affected. Allelopathy is an effective chemical weapon in the invasion process of exotic weeds. With radish {Raphanus salivas) and lettuce (Lactuca sativa) as receptor materials, the allelopathic effect of plant aqueous extract of A. philoxeroides was studied u-sing a Petri dish bioassay. In this process, plant protective enzyme activity was also measured to clarify the allelopathic mechanism. Seed germination rates of lettuce and radish showed significant allelopathic inhibition which gradually increased with an increase of the A. philoxeroides plant aqueous extract concentration. This inhibition in lettuce was significantly greater than in radish. A. philoxeroides plant aqueous extracts caused a general inhibition of the radish and lettuce seedlings growth. Inhibition on radicle growth was significantly greater than on the hypocotyl. At low concentrations (0. 01 g/mL), A. philoxeroides plant aqueous extracts promoted growth of hypocotyls but as the concentration increased, this promotion gradually diminished. Radish and lettuce hypocotyl growth were significantly inhibited at a concentration of 0. 04 g/mL. The degree of inhibition of radicle length and fresh weight gradually increased with increasing concentrations. The radicle growth of radish and lettuce seedlings was almost inhibited at a concentration of 0. 04 g/mL. The degree of inhibition of plant fresh weight in lettuce was more serious than in radish. Changes in protective enzyme activity were more complex. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities increased at low concentrations but as the concentration increased, SOD activity gradually decreased, while POD and CAT activities initially decreased and then increased. Malondialdehyde (MDA) content of radish and lettuce seedlings increased with increased

  5. Allelopathy of aqueous extract from Caragana intermedia root on seven kinds of shrubs and herbs and its chemical component analysis%中间锦鸡儿根水浸提液对7种灌草的化感作用及其化学成分分析

    Institute of Scientific and Technical Information of China (English)

    陈林; 杨新国; 宋乃平; 翟德苹; 赵伟; 刘学东

    2016-01-01

    为了揭示中间锦鸡儿( Caragana intermedia)在人工复合系统以及植被演替中的作用,研究了中间锦鸡儿根水浸提液对荒漠草原7种常见植物(苦豆子、沙打旺、草木樨、披碱草、苏丹草、柠条锦鸡儿和小叶锦鸡儿)的种子萌发和幼苗生长的影响。结果表明:一定质量浓度中间锦鸡儿根水浸提液处理对苦豆子、草木樨、苏丹草、柠条锦鸡儿和小叶锦鸡儿的种子萌发和幼苗生长有抑制作用,而对沙打旺和披碱草起到促进作用;此外,中间锦鸡儿根水浸提液在同一质量浓度处理下对苦豆子、苏丹草和小叶锦鸡儿的种子萌发具有抑制作用,而对其幼苗生长起到一定程度的促进作用。采用气相色谱质谱联用技术分析中间锦鸡儿根水浸提液,共鉴定出21种主要化合物,包括醇、酮、醚、酯、萜类、有机酸、卤代烷以及含氮化合物等8类物质。%Summary Allelopathy played an important role in interspecific relationships of plants . Effects of aqueous extract from Caragana intermedia root on seed germination and seedling growth of plant species in desert steppe were investigated , to reveal the function of C . intermedia in artificial compound system and vegetation succession . Seven common species were selected , including Sophora alopecuroides , Astragalus adsurgens , Melilotus of ficinalis , Elymus dahuricus , Sorghum sudanense , Caragana korshinskii and Caragana microphylla . Laboratory bioassays were conducted , and gas chromatography‐mass spectrometry (GC‐MS) was used to analyze the compounds in the aqueous extract from C . intermedia root . The results showed that allelopathic effects were observed for aqueous extract from C . intermedia root , but showed distinct influences on different species . Seed germination and seedling grow th of five species ( S . alopecuroides , M . of f icinalis , S . sudanense , C . korshinskii and C . microphylla) were

  6. Quantitative Trait Loci Analysis of Allelopathy in Rice

    DEFF Research Database (Denmark)

    Jensen, L B; Courtois, B; Olofsdotter, M

    2008-01-01

    the population phenotype was normally distributed. Two quantitative trait loci (QTLs) were located on chromosomes 4 and 7, explaining 20% of the phenotypic variation. A second relay seeding experiment was set up, this time including charcoal in the perlite. This screening showed that the allelopathic rice...

  7. Allelopathy of plant species of pharmaceutical importance to cultivated species

    OpenAIRE

    Álisson Sobrinho Maranho; Ary Vieira de Paiva

    2012-01-01

    This study aimed to identify possible allelopathic effects of leaf aqueous extracts of Baccharis dracunculifolia DC., Pilocarpus pennatifolius Lem., Cyperus rotundus L., Morus rubra L., Casearia sylvestris Sw., and Plectranthus barbatus Andr. on the germination and initial growth of Lactuca sativa L., Brassica oleracea L. cv. capitata, B. oleracea L. cv. italica, B. pekinenses L., B. campestris L., Lycopersicum esculentum Miller, and Eruca sativa L. To obtain the aqueous extracts, leaves prev...

  8. Allelopathy as a new strategy for sustainable ecosystems development.

    Science.gov (United States)

    Macias, Francisco A; Marin, David; Oliveros-Bastidas, Alberto; Varela, Rosa M; Simonet, Ana M; Carrera, Ceferino; Molinillo, Jose M

    2003-06-01

    Natural products involved in plant-plant and plant-microorganism ecological interaction (Allelochemicals) are an important potential source for alternative agrochemicals and pharmaceuticals, in order to solve the many problems derived from inadequate culture practices and abuse of synthetic herbicides. Isolation, structural determination, bioassay techniques and applicability for these compounds in crop protection and pharmaceutical research are discussed, and future trends on Allelochemicals applications are examined. The new strategies for sustainable ecosystems controlled by allelochemicals offer a particular interest for the development of human bases in space, since these products can stimulate or inhibit plant germination and growth, and permit to develop crops with low residue amounts in water, facilitating wastewater treatment and recycling. PMID:12897457

  9. Allelopathy of plant species of pharmaceutical importance to cultivated species

    Directory of Open Access Journals (Sweden)

    Álisson Sobrinho Maranho

    2012-11-01

    Full Text Available This study aimed to identify possible allelopathic effects of leaf aqueous extracts of Baccharis dracunculifolia DC., Pilocarpus pennatifolius Lem., Cyperus rotundus L., Morus rubra L., Casearia sylvestris Sw., and Plectranthus barbatus Andr. on the germination and initial growth of Lactuca sativa L., Brassica oleracea L. cv. capitata, B. oleracea L. cv. italica, B. pekinenses L., B. campestris L., Lycopersicum esculentum Miller, and Eruca sativa L. To obtain the aqueous extracts, leaves previously dried at a 1g.10mL-1 concentration were used, diluted in six solutions (10, 30, 50, 70, 90, and 100% and compared to control, distilled water, with five replications of 10 seeds for all vegetable species. The aqueous extracts of all species showed allelopathic potential for germination of seeds, the germination speed index, and the initial growth of shoots and roots of vegetable crops. The aqueous extracts of C. rotundus and P. barbatus promoted lower and higher allelopathic effects, respectively, and the vegetal structure mostly affected by the extracts was the primary root. The results indicate the existence of allelopathic potential in the species tested, so there’s a need for adopting care procedures when cultivating vegetables with them.

  10. Allelopathy as a potential strategy to improve microalgae cultivation

    OpenAIRE

    Bacellar Mendes, Leonardo Brantes; Vermelho, Alane Beatriz

    2013-01-01

    One of the main obstacles for continuous productivity in microalgae cultivation is the presence of biological contaminants capable of eliminating large numbers of cells in a matter of days or even hours. However, a number of strategies are being used to combat and prevent contamination in microalgae cultivation. These strategies include the use of extreme conditions in the culture media such as high salinity and high pH to create an unfavorable environment for the competitive organisms or pre...

  11. Allelopathy by extracts of Caatinga species on melon seeds

    OpenAIRE

    Andreya Kalyana de Oliveira; Maria de Fatima Barbosa Coelho; Salvador Barros Torres; Francisco Ésio Porto Diógenes

    2016-01-01

    The melon crop is of great socioeconomic importance in Brazil and some species from the Caatinga biome show allelopathic effects on other species. The aim of this study was to assess leaf and seed extracts of cumaru (Amburana cearensis (Allemao) A.C. Sm.), the jujube tree (Zizyphus joazeiro Mart.), Jucá (Caesalpinia ferrea Mart. Ex. Tul. Var. Ferrea) and mulungu (Erythrina velutina Willd.) on the emergence of melon seeds (Cucumis melo L.). Leaves and seeds were used to produce extracts for ea...

  12. Allelopathy by extracts of Caatinga species on melon seeds

    Directory of Open Access Journals (Sweden)

    Andreya Kalyana de Oliveira

    2016-04-01

    Full Text Available The melon crop is of great socioeconomic importance in Brazil and some species from the Caatinga biome show allelopathic effects on other species. The aim of this study was to assess leaf and seed extracts of cumaru (Amburana cearensis (Allemao A.C. Sm., the jujube tree (Zizyphus joazeiro Mart., Jucá (Caesalpinia ferrea Mart. Ex. Tul. Var. Ferrea and mulungu (Erythrina velutina Willd. on the emergence of melon seeds (Cucumis melo L.. Leaves and seeds were used to produce extracts for each species at concentrations of a 1%, b 0.5% c 0.25%, d 0.125% and e 0% (control. The experiment was conducted with each extract type and its respective concentrations in a completely randomized design, with four replicates, each of 20 seeds. The percentage emergence and rate index, percentage of abnormal seedlings, seedling dry matter and seedling shoot and root length were assessed. Seed extracts of A. cearensis prevented melon germination, whereas the other extracts had no effect on this variable. Leaf extracts of A. cearensis and leaf and seed extracts of Z. joazeiro, C. ferrea and E. velutina resulted in abnormal melon seedlings. The percentage of abnormal melon seedlings exceeded 30% when treated with C. ferrea seed extract at the highest concentration. Most extracts did not affect seedling dry matter, but E. velutina leaf and seed extract increased the dry matter accumulation of melon seedlings and Z. joazeiro seed extract decreased dry matter accumulation at a concentration of 0.25%. The highest concentrations of mulungu and jucá leaf extracts promoted the shoot growth of melon seedlings. The extract from E. velutina seeds negatively affected root length compared to the control, similar to the effect of C. ferrea and E. velutina leaf extracts at the highest concentrations. Extracts of different organs of Caatinga plants can affect the emergence and characteristics related to seedling growth, depending on the concentration. Most extracts did not affect germination or the emergence rate index, but affected seedling growth.

  13. Allelopathy Effect of Root Diffusate of Crops in Different Rotation Systems on Germination and Growth of Soybean Seed%不同轮作系统中作物根渗出物对大豆种子萌发的化感作用

    Institute of Scientific and Technical Information of China (English)

    李春杰; 赵丹; 司兆胜; 潘凤娟; 许艳丽

    2013-01-01

    为明确不同作物根渗出物对大豆种子的化感作用,用滤纸法研究了6种轮作系统中5种作物根渗出物对大豆种子发芽及芽生长的影响.结果表明:大豆种子在大豆连作(S…SS) 12年区土壤中种植后,在其根渗出物中大豆种子的发芽率为63.3%,与玉米-大豆-玉米(CSC)轮作区相比(发芽率96.7%),对大豆种子萌发有明显的抑制作用.在小麦-大豆-小 麦(WSW)、大豆-小 麦-玉米(SWC)和玉米-大豆-玉米(CSC)轮作区种植甜菜后,与相应轮作系统中种植其它作物相比,大豆种子在甜菜根渗出物中的发芽率和发芽势几乎最低,且在所有供试轮作系统中种植甜菜后均不利于下茬大豆种子发芽后的芽生长;而在所有轮作系统中种植亚麻后,其根渗出物更好地促进了下茬大豆种子发芽,且芽长势良好.玉米除了在小麦-大豆-小 麦(WSW)轮作区外,在其它轮作系统中种植后对大豆种子发芽影响不大.在玉米-大豆-玉米(CSC)、大豆-小麦-大豆(SWS)和裸地(Nudation)中小麦根渗出物利于大豆种子发芽和芽生长.总之,同一作物在不同轮作系统中种植或不同作物在同一轮作系统种植后,作物的根渗出物对大豆种子发芽和芽生长的影响有显著差异.%In order to clarify the allelopathy effect of root diffusate of different crops on soybean seeds, the effect of root diffu-sates of crop in different rotation systems on germination and sprout growth of soybean seed were tested by the filter paper method. The germination rate of soybean seed was 63. 3% in the root diffusates of soybean planted in soybean continuous cropping for 12 years(S…SS) , which indicated germination percentage of soybean seed inhibited by the soybean root diffusates of continuous cropping system in comparison with Corn-Soybean-Corn( CSC) rotation system with 96. 7% germination. Germination rate and germinability of soybean seed were almost the lowest in the root diffusate

  14. Karlodinium veneficum in India: Effect of fixatives on morphology and allelopathy in relation to Skeletonema costatum

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, R.K.; Chitari, R.R.; Anil, A.C.

    such as allelopathic chemicals, some toxic algae can also negatively influence co-occurring phytoplankton 14 . Such production of toxins or release of organic compounds is considered a part of the defence mechanisms or competition strategies among phytoplankton 15...

  15. Allelopathy in two species of Chenopodium -inhibition of germination and seedling growth of certain weeds

    Directory of Open Access Journals (Sweden)

    Subhash C. Datta

    2014-02-01

    Full Text Available The activity of washed leaf and inflorescence material of Chenopodium ambrosioides and C. murale, decaying leaves and inflorescences, and field soils collected beneath Chenopodium plants were examined in terms of the inhibition of seed germination and seedling growth of five weeds, viz. Abutilon indicum, Cassia sophera var. purpurea, C. tora, Evolvulus numularius and Tephrosia hamiltonii. The allelopathic pattern varied in each of the two test species and this depended on the type of test matter. However, the germination as well as the root and hypocotyl growth of A. indicum and E. nummularius were more hampered by phytotoxins or inhibitors from Chenopodium than were the other weeds. Since the leaf and inflorescence of Chenopodium formed the source of inhibitors, the respective plant-parts from the two species were chemically analysed and the presence of three terpenes (p-cymene, ascaridole and aritazone from C. ambrosioides and an organic acid (oxalic acid from C. murale were implicated in the allelopathic effect.

  16. Contribution of a phytotoxic compound to the allelopathy of Ginkgo biloba.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Takeshita, Sayaka

    2013-11-01

    Ginkgo (Ginkgo biloba L.) has not changed over 121 million years. There may be unknown special strategy for the survival. Gingko litter inhibited the growth of weed species ryegrass (Lolium multiflorum L.). The inhibition was greater with the litter of the close position than that of the far position from the gingko tree. A phytotoxic substance, 2-hydroxy-6-(10-hydroxypentadec-11-enyl)benzoic acid (HHPEBA) was isolated in the litter. HHPEBA concentration was greater in the litter of the close position than that of the far position from the tree. HHPEBA inhibited the ryegrass growth at concentrations greater than 3 μM. HHPEBA was estimated to be able to cause 47-62% of the observed growth inhibition of ryegrass by the gingko litter. Therefore, HHPEBA may contribute to the inhibitory effect caused by ginkgo litter and may provide a competitive advantage for gingko to survive through the growth inhibition of the neighboring plants.

  17. Leucaena allelopathy on weeds and soybean seed germination / Alelopatia de Leucena sobre soja e plantas invasoras

    Directory of Open Access Journals (Sweden)

    Raquel Leszczynski

    2009-07-01

    Full Text Available With the advance of agriculture, there was consequent rising in environment degradation. Therefore, It is interesting the use of plants which have in their chemical composition substances capable of helping in the control of weeds to minimize the use of pesticides. Hence, the objective of this paper was to evaluate solutions of leucena extract on weeds that are frequent on soybean crop. The treatments were leucena extracts at 0, 20, 40, 60, 80 and 100% at room temperature water and water heated to 80°C. The extracts were obtained by crushing 200g of leucena leaves and mixing them with one liter of distilled water with the help of a blender. Seeds were kept in B.O.D. at a temperature of 25°C, with a photoperiod of 12 hours of light. Evaluations were done on a daily basis, from the first to the last day of the experiment, varying according to the species. Results show a negative interference of the extracts, both hot and cold, in the root length of Ipomoea grandifolia, in the percentage of germination and in the root length of Arrowleaf sida and Hair beggarticks. There was no negative interference in the analyzed parameters for soybean seeds. Thus, the results indicate allelopatic potential of Leucaena leuucocephala as an alternative for the management of weeds without interfering on the development of the soybean crop.Com o desenvolvimento da agricultura surgiram os conseqüentes aumentos na degradação ambiental. Assim, estuda-se a utilização de plantas que possuam em sua composição química substâncias capazes de auxiliar no controle de plantas invasoras, amenizando o uso de agrotóxicos. Desta forma, o objetivo do trabalho foi avaliar soluções de extratos de leucena sobre plantas invasoras que freqüentemente ocorrem na cultura da soja. Foram utilizados como tratamentos os seguintes extratos de leucena nas proporções de: 0, 20, 40, 60, 80 e 100% com água à temperatura ambiente e com água aquecida à 80°C. Os extratos foram obtidos triturando-se 200 g de folhas de leucena em um litro de água destilada, com auxílio de um liquidificador. As sementes foram mantidas em B.O.D. à temperatura de 25°C, com fotoperíodo de 12 horas de luz. As avaliações foram diárias, do primeiro ao último dia de experimento, este variando conforme a espécie. Os resultados demonstraram interferência negativa dos extratos, tanto quente quanto frio, no comprimento de raiz de corda de viola, na porcentagem de germinação e no comprimento de raiz de guanxuma e picão-preto. Não foram constatadas interferências negativas nos parâmetros analisados para as sementes de soja. Sendo assim, os resultados obtidos indicam potencial alelopático da espécie Leucaena leuucocephala como alternativa de manejo de plantas invasoras sem interferir no desenvolvimento da cultura da soja.

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

    Institute of Scientific and Technical Information of China (English)

    Jiao XU; Wenehao XU; Yajun YANG; Bu TAO; Jinlin ZHANG

    2008-01-01

    To identify the allelopathic effect of Flaveria bidentis (L.) Kuntze (F, bMenti) on other plants, the effects of different extracts from F. bidentis on the growth of sev-eral 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 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℃ to 193.5℃, 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

  19. Involvement of allelopathy in the formation of monospecific colonies of ferns.

    Science.gov (United States)

    Kato-Noguchi, Hisashi

    2015-05-01

    Some fern species often dominate plant communities by forming large monospecific colonies. However, the potential mechanism for this domination of the ferns remains obscure. Many plants secrete a wide range of compounds into the rhizosphere and change the chemical and physical properties of the rhizosphere soil. Through the secretion of compounds, such as allelopathic substances, plants inhibit the germination and growth of neighboring plants to compete more effectively for the resources. Ferns contain a variety of secondary metabolites and some of those compounds are released from the ferns into the rhizosphere soil, either as exudates from living ferns or by decomposition of fern residues in sufficient quantities to affect the germination and growth of neighboring plants as allelopathic substances. Therefore, allelopathic chemical interaction of the ferns with neighboring plants may play an important role in the formation of the monospecific colonies of the ferns.

  20. Multiple periodic solutions for a discrete time model of plankton allelopathy

    OpenAIRE

    Zhang Jianbao; Fang Hui

    2006-01-01

    We study a discrete time model of the growth of two species of plankton with competitive and allelopathic effects on each other N1(k+1) = N1(k)exp{r1(k)-a11(k)N1(k)-a12(k)N2(k)-b1(k)N1(k)N2(k)}, N2(k+1) = N2(k)exp{r2(k)-a21(k)N2(k)-b2(k)N1(k)N1(k)N2(k)}. A set of sufficient conditions is obtained for the existence of multiple positive periodic solutions for this model. The approach is based on Mawhin's continuation theorem of coincidence degree theory as well as some a priori estimates. Some...

  1. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; van Nes, E.H.; Van Donk, E.

    2007-01-01

    Abstract Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still controversi

  2. Macrophyte-phytoplankton interactions: the relative importance of allelopathy versus other factors

    NARCIS (Netherlands)

    Mulderij, G.; Nes, van E.H.; Donk, van E.

    2007-01-01

    Submerged aquatic macrophytes are important in shallow aquatic ecosystems because they stabilize the macrophyte-dominated state by increasing water transparency in various ways. One of these is the excretion of allelopathic substances inhibitory to phytoplankton, but it is still controversial whethe

  3. Impact of submerged macrophytes including charophytes on phyto- and zooplankton communities: allelopathy versus other mechanisms

    NARCIS (Netherlands)

    Van Donk, E.; Van de Bund, W.J.

    2002-01-01

    Submerged macrophytes are crucial for the stabilization of the clear water state in shallow, mesotrophic and eutrophic lakes. Especially, charophytes often play an important role because they are typically rapid colonizers and because charophyte meadows are believed to have a particularly strong pos

  4. Biologically active secondary metabolites of barley. I. Developing techniques and assessing allelopathy in barley.

    Science.gov (United States)

    Liu, D L; Lovett, J V

    1993-10-01

    Allelopathic effects of barley (Hordeum vulgare L.) on white mustard (Sinapis alba L.) were assessed using modified bioassays that reduced other environmental influences. In a Petri dish bioassay, germination of white mustard was delayed and the radicle lengths were significantly inhibited at a density of 0.5 barley seed/cm(2). In a 'siphoning' bioassay apparatus, when the two species were sown together, radicle elongation of white mustard was not inhibited one day after sowing but became increasingly inhibited as bioassay time increased. Barley allelochemicals were released from the roots in a hydroponic system for at least 70 days after commencement of barley germination. Solutions removed from the hydroponic system of growing barley delayed germination and inhibited growth of white mustard. The allelopathic activity of barley was further confirmed at a density of 0.3 barley seed/cm(2) in a modified stairstep apparatus. PMID:24248571

  5. Importance of Allelopathy as Peudo-Mixotrophy for the Dynamics and Diversity of Phytoplankton

    OpenAIRE

    Shovonlal, Roy

    2015-01-01

    Understanding the dynamics and diversity of marine phytoplankton is essential for predicting oceanic primary production, oxygen generation and carbon sequestration. Several top-down and bottom-up factors lead to complex phytoplankton dynamics. Complexities further arise from inter-species interactions within phytoplankton communities. Consequently, some of the basic questions on phytoplankton diversity, identified long ago, still puzzle the ecologists: for example, what regulates the diver...

  6. Alelopatia de cultivos de cobertura vegetal sobre plantas infestantes = Allelopathy of cover crop on weed plants

    Directory of Open Access Journals (Sweden)

    Luciene Kazue Tokura

    2006-07-01

    Full Text Available O presente trabalho avaliou o potencial alelopático de cultivos de cobertura vegetal de trigo, aveia preta, milheto, nabo forrageiro e colza sobre o desenvolvimento de plantas infestantes e verificou qual das coberturas vegetais exerce maior controle sobre as mesmas. Os cultivos de cobertura vegetal foram implantados sob preparo convencional (uma aração e uma gradagem no Núcleo Experimental de Engenharia Agrícola (NEEA, da Universidade Estadual do Oeste do Paraná (Unioeste, Cascavel, Estado do Paraná. Mensalmente, realizou-se o acompanhamento e identificação das plantas infestantes emersas nas áreas de cobertura vegetal no período de agosto de 2000 a agosto de 2001. Os resultados obtidos permitiram concluir que das espécies encontradas, o capim marmelada foi o que apresentou maior potencial alelopático e a erva-de-santa-maria o menor. As coberturasvegetais que apresentaram melhor controle do total de plantas infestantes presentes na área experimental, incluindo àquelas com reconhecido potencial alelopático, foram aveia preta, colza, nabo forrageiro e milheto.This work evaluated the cover crop allelopathic potential of wheat, black oat, pearl millet, turnip and rape on the development of weed plants. It also verified which cover crop has larger control on the weed plants. The cover crop was implanted under conventional tillage (one disk plowing plus one disk harrowing in the Experimental Nucleus of Agricultural Engineering (NEEA, of the State University of the West of Paraná (Unioeste, Cascavel, Paraná State. Monthly (from August 2000 to August 2001, weed plants identification in the cover crop area was made. Results showed that from the found species, the alexander grass was the one that presented larger allelopathic potential, and, the mexican-tea was the one that presented smaller control. The vegetable coverings that presented larger control of the total of weed plants in the experimental area, including those with recognized allelopathic potential, was black oat, rape, turnip and pearl millet.

  7. DISCUSS SEVERAL RESEARCHED PROBLEMS OF ALLELOPATHY IN SOYBEAN CONTINUOUS CROPPING BARRIER%论大豆连作障碍中有关化感作用(Allelopathy)研究的若干问题

    Institute of Scientific and Technical Information of China (English)

    阎飞; 韩丽梅; 杨振明

    2000-01-01

    本文着重地探讨了大豆连作障碍中有关化感作用研究应注意的若干问题,具体内容如下:(1)化感物质的提取源、提取剂及其收集方法的选取;(2)生物检测的参数、受体植物及其生长的环境基质的选用;(3)数据统计分析方法的选定等。以便为研究大豆连作障碍机理提供科学的方法。%Several problems as follow on allelopathic are mainly approached so as to supplyresearch methods on barrier mechanism of soybean continuous cropping (1) Selecting ex-traction sources, extracts and collection methods of allelochemicals; (2)Choose para-me-ters of bioassay, species of test plant and their growth ground substance; (3)Establish datastatistical analysis

  8. Research on allelopathy of limpograss%扁穗牛鞭草的他感作用研究

    Institute of Scientific and Technical Information of China (English)

    兰兴平

    2005-01-01

    扁穗牛鞭草是我国南方重要的饲草来源,但在与豆科牧草混播时却难以成功,因为它具有较强的竞争能力和对其他植物的排斥作用.本研究通过牛鞭草根、茎、叶浸出液对豆科牧草种子发芽率和发芽势的影响,以寻找能与扁穗牛鞭草混播的草种,以提高牧草的产量和质量.试验结果表明,牛鞭草的根浸出液对所有试验豆科牧草种子(川引拉丁诺白三叶、Dory红三叶、Cherokee红三叶、巫溪红三叶、箭三叶)均有抑制作用,而茎、叶浸出液对豆科牧草种子的抑制作用不明显.

  9. Prymnesium parvum revisited: relationship between allelopathy, ichthyotoxicity, and chemical profiles in 5 strains

    DEFF Research Database (Denmark)

    Blossom, Hannah E.; Rasmussen, Silas Anselm; Andersen, Nikolaj Gedsted;

    2014-01-01

    Bioassay-guided discovery of ichthyotoxic algal compounds using in vivo fish assays is labor intensive,costly, and highly regulated. Since the mode of action of most known algal-mediated fish-killing toxinsis damage to the cell membranes in the gills, various types of cell-based bioassays are often...... (Oncorhynchusmykiss, 10 g) and the microalga Teleaulax acuta. No relationship between median effective concentrations(EC50s) on fish and median lethal concentrations (LC50s) on algae was observed in the 5 strains showingthat a microalgal bioassay cannot be used as a proxy for ichthyotoxicity. Fish were more sensitive...... to P.parvum with EC50s ranging from 6 × 103to 40 × 103cells ml−1, compared to the test alga where LC50sranged from 30 × 103to nearly non-toxic at 500 × 103cells ml−1. In addition, the cellular concentrationsof two recently suggested ichthyotoxins produced by P. parvum, the “golden algae toxins”, GAT...

  10. 木薯、野花生的他感作用%Allelopathy of Manihot utilissima and Arachis pintoi

    Institute of Scientific and Technical Information of China (English)

    朱朝华; 骆焱平; 许敏; 颜桂军

    2006-01-01

    用木薯(Manihot utilissima Crantz.)茎叶的汁液及根系土壤分别处理南瓜(Cucurbita moschata Duch.)、玉米(Zea mays L)、豇豆(Vigna sinensis)、花生(Arachis hypogaea)、热研2号柱花草(Stylosanthes guiaensis cv.Reyan No.2)、热研8号坚尼草(Panicum maximum cv.Reyan No.8);用野花生(Arachis pintoi)茎叶汁液及根系土壤分别处理胜红蓟(Ageratum conyzoides L)、小飞蓬[Comnyza canadensis(L.)Cronq.]、粘人草(Bidens pilosa L.),测定其对种子萌发和生长的影响.结果表明:木薯茎叶的汁液对南瓜、玉米、豇豆、花生、热研2号柱花草、热研8号坚尼草的种子萌发和生长均有影响;木薯根系土壤对南瓜、玉米、豇豆、花生的种子萌发影响均不明显,对南瓜、玉米、豇豆、花生的露白种子生长均有影响.野花生茎叶的汁液对胜红蓟的种子萌发有影响,对胜红蓟、小飞蓬和粘人草的生长均有影响;野花生根系土壤对胜红蓟和小飞蓬的种子萌发影响均不明显,对胜红蓟、小飞蓬和粘人草的生长均有影响.

  11. Allelopathy in the tropical alga Lobophora variegata (Phaeophyceae): mechanistic basis for a phase shift on mesophotic coral reefs?

    Science.gov (United States)

    Slattery, Marc; Lesser, Michael P

    2014-06-01

    Macroalgal phase shifts on Caribbean reefs have been reported with increasing frequency, and recent reports of these changes on mesophotic coral reefs have raised questions regarding the mechanistic processes behind algal population expansions to deeper depths. The brown alga Lobophora variegata is a dominant species on many shallow and deep coral reefs of the Caribbean and Pacific, and it increased in percent cover (>50%) up to 61 m on Bahamian reefs following the invasion of the lionfish Pterois volitans. We examined the physiological and ecological constraints contributing to the spread of Lobophora on Bahamian reefs across a mesophotic depth gradient from 30 to 61 m, pre- and post-lionfish invasion. Results indicate that there were no physiological limitations to the depth distribution of Lobophora within this range prior to the lionfish invasion. Herbivory by acanthurids and scarids in algal recruitment plots at mesophotic depths was higher prior to the lionfish invasion, and Lobophora chemical defenses were ineffective against an omnivorous fish species. In contrast, Lobophora exhibited significant allelopathic activity against the coral Montastraea cavernosa and the sponge Agelas clathrodes in laboratory assays. These data indicate that when lionfish predation on herbivorous fish released Lobophora from grazing pressure at depth, Lobophora expanded its benthic cover to a depth of 61 m, where it replaced the dominant coral and sponge species. Our results suggest that this chemically defended alga may out-compete these species in situ, and that mesophotic reefs may be further impacted in the near future as Lobophora continues to expand to its compensation point. PMID:26988322

  12. Allelopathy of aqueous leaf extracts from the invasive alien tree Pittosporum undulatum on germination and growth of barnyard grass

    Directory of Open Access Journals (Sweden)

    Fernando Bertol Carpanezzi

    2014-09-01

    Full Text Available Barnyard grass (Echinochloa crusgalli (L. P. Beauv. is a herbicide-resistant weed that brings negative impacts to rice crops and threatens floodplains biodiversity worldwide. This study aimed to investigate allelopathic influences of extracts from Pittosporum undulatum Vent. (cheesewood leaves on barnyard grass. Leachates in concentrations of 20%, 15%, 10%, 5% and 2.5% (w/v, aqueous extracts from powdered leached and non-leached leaves (10%, 7,5%, 5%, 2.5% and 1.25% for both, coumarin solution at 0.6 mM and original Roundup ® in concentration according to the label information were prepared. Petri-dishes germination bioassays, with counting at each 12 hours, allowed to determinate both germinability and germination rate; polyethylene glycol (PEG 6000 solutions were prepared to evaluate osmotic effects. In growth tests, seedlings were exposed for seven days, when root and shoot lengths were measured. Germination was sensitive to extracts from powdered leaves. In regard to growth, roots showed dose-dependent length reduction and necrosis. Inhibitory effects from different aqueous extracts suggest action of both internal and external leaf allelochemicals, raising the possibility of Pittosporum undulatum use for barnyard grass control.

  13. 黄花草木樨对杂草的化感作用研究%The Allelopathy of Yellow Sweet Clover on Weeds

    Institute of Scientific and Technical Information of China (English)

    邬彩霞; 刘苏娇; 赵国琦; 徐俊

    2015-01-01

    为探讨黄花草木樨(Melilotus officinalis)水浸提液对田间常见杂草的化感抑制作用以及利用黄花草木樨化感作用进行生物除草的可行性,采用生物检测法研究黄花草木樨水浸提液对藜(Chenopodium album)、臭草(Meli-ca scabrosa)、籽粒苋(Amaranthush ypochondriacus)、稗草(Echinochloa crus-galli)、萹蓄(Pol ygonum aviculare)、山苦荬(Ixeris chinensis)、车前草(Plantago asiatica)等7种杂草种子萌发和幼苗生长的化感效应;同时测定黄花草木樨干草粉对田间杂草生物量的抑制效应.结果表明:黄花草木樨茎叶水浸提液处理能显著抑制籽粒苋、山苦荬、藜、稗草及车前草的种子萌发(P<0.05);能显著抑制藜、籽粒苋、稗草、山苦荬、车前草的幼苗生长(P<0.05);黄花草木樨干草粉能有效降低田间杂草生物量,且对田间杂草的抑制效应随施用量的增加而增强,在施用量达90g·m-2时,对田间杂草数量和干重的抑制均达到显著水平(P<0.05).因此,黄花草木樨的抑草能力具有选择性,对不同种杂草的作用方式和作用强度存在差异;黄花草木樨干草粉的施用量在90g·m-2及以上时,能显著降低田间杂草的数量及重量.

  14. Alelopatia de extratos aquosos de canela-sassafrás (Ocotea odorifera (Vell. Rohwer Allelopathy of Brazilian sassafras (Ocotea odorifera (Vell. Rohwer aqueous extracts

    Directory of Open Access Journals (Sweden)

    Flávia Maria da Silva Carmo

    2007-09-01

    Full Text Available Estudos de alelopatia investigam os efeitos positivos e negativos que metabólitos secundários de plantas, microrganismos ou fungos exercem sobre o desenvolvimento de indivíduos vizinhos. Nesse trabalho foram investigados os efeitos de extratos aquosos de folhas, cascas de tronco e cascas de raízes de canela-sassafrás (Ocotea odorifera (Vell. Rowher sobre a germinabilidade das sementes, desenvolvimento do sistema radicular e da parte aérea, teor de clorofila da parte aérea e respiração das células radiculares de plântulas de sorgo (Sorghum bicolor L. Moench cv. Embrapa BR 303. Os extratos foram preparados adicionando o material vegetal seco e moído oriundo de cada órgão à água destilada e deionizada na proporção 1:10 (p/v. Após agitação constante por 24 h, as soluções foram decantadas e filtradas através de papel de filtro sob vácuo, constituindo os extratos testados. Os extratos aquosos de cascas de tronco e de raízes causaram inibição do desenvolvimento do sistema radicular das plântulas de sorgo e a sua parte aérea teve o crescimento estimulado pelo extrato de cascas de raízes. Os extratos de folhas e de cascas de tronco induziram aumento da biomassa fresca do sistema radicular e diminuição significativa do teor de clorofila. Todos os extratos causaram efeitos negativos sobre a respiração radicular das plântulas de sorgo. Concluiu-se que metabólitos secundários da canela-sassafrás causaram alterações metabólicas e morfológicas nas plantas de sorgo e que, portanto, a presença de canela-sassafrás no ambiente pode desencadear efeitos similares sobre outras espécies vegetais na sua vizinhança.Allelopathic studies investigate the positive and negative effects of secondary metabolites of plants, microorganisms and fungi on the development of neighboring individuals. In this work, the allelopathic effects of aqueous extracts of leaves, bark and root bark of Brazilian sassafras (Ocotea odorifera (Vell. Rowher on seed germination, root and shoot growth, chlorophyll content and respiratory activity of the root cells of sorghum seedlings (Sorghum bicolor (L Moench cv. Embrapa BR 303 were analyzed. The extracts were prepared by adding dried, powdered plant material to distilled non-ionized water at 1:10 (w/v. After continuous agitation for 24 h, these solutions were decanted and vacuum-filtered through filter paper, thus constituting the tested extracts. Bark and root bark aqueous extracts caused root growth inhibition in sorghum seedlings while shoot growth was stimulated by the root bark extract. Leaf and bark extracts induced an increase in wet root biomass and a decrease in chlorophyll content. All extracts caused negative effects on sorghum seedling root cell respiration. We concluded that secondary metabolites from Brazilian sassafras caused metabolic and morphological alterations in the sorghum seedlings and the presence of these plants in the environment can cause similar effects on other neighboring plant species.

  15. Preliminary Study on the Allelopathy of Piper nigrum L.%胡椒化感作用及其机理研究

    Institute of Scientific and Technical Information of China (English)

    占胜利; 朱朝华; 王兰英; 戴进用; 邓昌盛

    2009-01-01

    [目的]为建立合理的植物间套作机制、杂草的生物防治及研制新型植物源除草剂提供科学依据.[方法]通过测定胡椒叶水浸液对绿豆、萝卜、柱花草和刺苋种子萌发和幼苗生长的影响,对胡椒的化感作用及其机理进行研究.[结果]胡椒叶水浸液对萝卜、柱花草和刺苋的种子萌发表现出不同程度的抑制作用,且随着水浸液浓度的增加,抑制效应增大,达到0.05 g/ml时,抑制作用最强;对不同受体植物幼苗生长的影响表现为低浓度促进,高浓度抑制的双重效应.萝卜体内的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性随着水浸液浓度的增加呈先升高后降低的趋势,丙二醛(MDA)含量增大.[结论]该研究为胡椒化感作用的开发和利用提供了科学的理论依据.

  16. 五倍子对铜绿微囊藻的化感作用%Allelopathy of Galla chinensis on Microcystic aeruginosa

    Institute of Scientific and Technical Information of China (English)

    聂江力; 裴毅

    2014-01-01

    以五倍子水提液和五倍子主要成分没食子酸水溶液为试材,将其配制成不同浓度后,分别对铜绿微囊藻(Microc ystic aeruginosa)连续处理168 h,测定其对藻液中叶绿素a含量的影响.结果表明:随着五倍子和没食子酸浓度的增加和处理时间的延长,藻液中叶绿素a含量均显著降低,具有明显量-效关系和时间-效应关系;五倍子水提液能显著抑制铜绿微囊藻的生长,五倍子的主要成分没食子酸可能是其主要化感物质.

  17. Alelopatia de Joanesia princeps Vell. e Casearia sylvestris Sw. sobre espécies cultivadas Allelopathy of Joanesia princeps Vell. and Casearia sylvestris Sw. on the cultivated species

    Directory of Open Access Journals (Sweden)

    Rafael Aguiar Capobiango

    2009-12-01

    Full Text Available Metabólitos secundários produzidos em algumas plantas podem provocar alterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. O objetivo do trabalho foi avaliar o efeito alelopático de extratos aquosos de folhas de Joanesia princeps e Casearia sylvestris na germinação e no desenvolvimento inicial de plântulas de Brassica oleracea cv. capitata, Lactuca sativa cv. grand rapids e Lycopersicum esculentum. Foram testadas seis concentrações de cada extrato (10, 30, 50, 70, 90 e 100% além do controle água destilada. Os extratos aquosos de J. princeps e C. sylvestris reduziram e, ou inibiram significativamente o percentual de geminação das sementes, o crescimento inicial da parte aérea e do sistema radicular de todas as espécies cultivadas e causaram severas anormalidades nas plântulas. Os resultados indicam a existência de potencial alelopático de J. princeps e C. sylvestris.Secondary metabolites produced in some plant species can provoke development changes in other plants or even in other organisms. The objective of this work was to identify the possible allelopathic effects of the aqueous extracts of Joanesia princeps and Casearia sylvestris leaves in the germination and initial growth of Brassica oleracea cv. capitata, Lactuca sativa cv. grand rapids and Lycopersicum esculentum seedlings. Six concentrations of each extract (10, 30, 50, 70, 90 and 100% were tested besides distilled water control. The aqueous extracts of J. princeps and C. sylvestris significantly reduced the seed germination percentage, initial growth of the aerial section and root system of all cultivated species in which they caused severe seedlings damage. The results indicate existence of allelopathic potential in J. princeps and C. sylvestris.

  18. Effects of Soil Characteristics, Allelopathy and Frugivory on Establishment of the Invasive Plant Carpobrotus edulis and a Co-Occuring Native, Malcolmia littorea

    OpenAIRE

    Novoa, Ana; González, Luís; Moravcová, Lenka; Pyšek, Petr

    2012-01-01

    Background The species Carpobrotus edulis, native to South Africa, is one of the major plant invaders of Mediterranean coastal ecosystems around the world. Invasion by C. edulis exerts a great impact on coastal habitats. The low number of native species in invaded communities points to the possible existence of mechanisms suppressing their germination. In this study we assessed whether soil factors, endozoochory, competition and allelopathic effects of the invader affect its own early establi...

  19. Effects of soil characteristics, allelopathy and frugivory on establishment of the invasive plant Carpobrotus edulis and a co-occurring native, Malcolmia littorea.

    Directory of Open Access Journals (Sweden)

    Ana Novoa

    Full Text Available BACKGROUND: The species Carpobrotus edulis, native to South Africa, is one of the major plant invaders of Mediterranean coastal ecosystems around the world. Invasion by C. edulis exerts a great impact on coastal habitats. The low number of native species in invaded communities points to the possible existence of mechanisms suppressing their germination. In this study we assessed whether soil factors, endozoochory, competition and allelopathic effects of the invader affect its own early establishment and that of the native species Malcolmia littorea. We used laboratory solutions representing different chemical composition and moisture of the soil, herbivore feeding assays to simulate seed scarification and rainwater solutions to account for the effect of differently aged C. edulis litter. PRINCIPAL FINDINGS: We show that unlike that of the native species, germination and early growth of C. edulis was not constrained by low moisture. The establishment of C. edulis, in terms of germination and early growth, was increased by scarification of seeds following passage through the European rabbit intestines; the rabbits therefore may have potential implications for plant establishment. There was no competition between C. edulis and M. littorea. The litter of the invasive C. edulis, which remains on the soil surface for several years, releases allelopathic substances that suppress the native plant germination process and early root growth. CONCLUSIONS: The invasive species exhibits features that likely make it a better colonizer of sand dunes than the co-occurring native species. Allelopathic effects, ability to establish in drier microsites and efficient scarification by rabbits are among the mechanisms allowing C. edulis to invade. The results help to explain the failure of removal projects that have been carried out in order to restore dunes invaded by C. edulis, and the long-lasting effects of C. edulis litter need to be taken into account in future restoration projects.

  20. 多裂骆驼蓬对食荚豌豆的化感作用研究%Allelopathy of Peganum multisectum Maxim Bobr on edible podded pea

    Institute of Scientific and Technical Information of China (English)

    刘建新; 赵国林

    2007-01-01

    试验研究了多裂骆驼蓬醇提取物浸种对食荚豌豆种子萌发、幼苗生长及生理生化性状的影响.结果表明,多裂骆驼蓬醇提取物浸种显著抑制食荚豌豆种子的萌发和幼苗生长,萌发率、发芽指数和与萌发有关的淀粉酶活性降低,株高、根体积、根系和地上部干重减小,根茎比下降;多裂骆驼蓬醇提取物浸种处理的幼苗根系活力和叶片硝酸还原酶活性、叶绿素和可溶性蛋白质含量下降;超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性降低,丙二醛(MDA)含量和过氧化物酶(POD)活性升高,根系过氧化物同工酶表达受抑.

  1. Allelopathy in agroforestry systems: the effects of leaf extracts ofCupressus lusitanica and threeEucalyptus spp. on four Ethiopian crops

    DEFF Research Database (Denmark)

    Lisanework N.; Michelsen, Anders

    1993-01-01

    The potential allelopathic effect ofCupressus lusitanica, Eucalyptus globulus, E. camaldulensis andE. saligna on seed germination, radicle and seedling growth was investigated with four crops:Cicer arietinum (chickpea),Zea mays (maize),Pisum sativum (pea) andEragrostis tef (teff). Aqueous leaf ex...

  2. Alelopatia em extratos de frutos de juazeiro (Ziziphus joazeiro Mart. - Rhamnaceae Allelopathy caused by fruit extract of juazeiro (Ziziphus joazeiro Mart. - Rhamnaceae

    Directory of Open Access Journals (Sweden)

    Andreya Kalyana de Oliveira

    2009-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o potencial alelopático do extrato de frutos de juazeiro (Ziziphus joazeiro Mart. sobre as sementes de alface (Lactuca sativa. O experimento foi conduzido em delineamento inteiramente casualizado com 4 repetições e cinco tratamentos (0%, 25%, 50%, 75% e 100% de concentração do extrato bruto. O extrato bruto foi obtido após a extração manual da polpa do fruto e agitação com água em liquidificador utilizando-se 50g de polpa para 500ml de água, e o mesmo foi feito com a casca do fruto. Os resultados mostraram efeito do extrato dependendo da concentração. As maiores concentrações do extrato (100%, 75% e 50% da polpa dos frutos Z. joazeiro apresentaram efeito alelopático desfavorável sobre a germinação de alface, reduzindo-a em 100%, 98,75% e 82,5% respectivamente. O extrato das cascas dos frutos nas concentrações de 75% e 100% reduziu a germinação da alface em 28,75% e 78,75%.This study aimed to identify the allelopathic activity of extracts obtained from Ziziphus joazeiro fruits on the germination of Lactuca sativa L. A randomized design was used with four replications and five treatments (0%, 25%, 50%, 75% and 100% concentration of the crude extract. The crude extract was obtained after manual extration of the fruit pulp and agitation with water in a blender using 50g of pulp in 500ml of water. The same was done with the fruit rind. The results showed the effect of the extract depending on concentration. The greatest extract concentrations (100%, 75% and 50% of Z. joazeiro fruit pulp had an unfavorable allelopathic effect on lettuce germination, having reduced it by 100%, 98.75% and 82.5% respectively. The extract of the fruits rinds in concentrations of 75% and 100% reduced lettuce germination by 28.75% and 78.75%.

  3. A less saline Baltic Sea promotes cyanobacterial growth, hampers intracellular microcystin production, and leads to strain-specific differences in allelopathy.

    Directory of Open Access Journals (Sweden)

    Andreas Brutemark

    Full Text Available Salinity is one of the main factors that explain the distribution of species in the Baltic Sea. Increased precipitation and consequent increase in freshwater inflow is predicted to decrease salinity in some areas of the Baltic Sea. Clearly such changes may have profound effects on the organisms living there. Here we investigate the response of the commonly occurring cyanobacterium Dolichospermum spp. to three salinities, 0, 3 and 6. For the three strains tested we recorded growth, intracellular toxicity (microcystin and allelopathic properties. We show that Dolichospermum can grow in all the three salinities tested with highest growth rates in the lowest salinity. All strains showed allelopathic potential and it differed significantly between strains and salinities, but was highest in the intermediate salinity and lowest in freshwater. Intracellular toxin concentration was highest in salinity 6. In addition, based on monitoring data from the northern Baltic Proper and the Gulf of Finland, we show that salinity has decreased, while Dolichospermum spp. biomass has increased between 1979 and 2013. Thus, based on our experimental findings it is evident that salinity plays a large role in Dolichospermum growth, allelopathic properties and toxicity. In combination with our long-term data analyses, we conclude that decreasing salinity is likely to result in a more favourable environment for Dolichospermum spp. in some areas of the Baltic Sea.

  4. The mutual allelopathy of Vallisneria spiralis Linn. And Microcystis aeruginosa%苦草与铜绿微囊藻的相互化感作用

    Institute of Scientific and Technical Information of China (English)

    陈卫民; 张清敏; 戴树桂

    2009-01-01

    在排除细菌作用和营养竞争的实验室条件下,对苦草和铜绿微囊藻进行混合培养和分开培养,探讨了苦草和铜绿微囊藻的相互化感作用.结果表明,苦草的存在对铜绿微囊藻的生长有明显的抑制;铜绿微囊藻对苦草生长的抑制,必须与藻对苦草的遮光作用相结合才能完成.藻的丙二醛(MDA)积累和藻叶绿素a含量降低表明,苦草释放的化感物质可能造成了铜绿微囊藻细胞内活性氧的增多,影响了正常的光合作用,导致藻细胞死亡.铜绿微囊藻则是通过减弱光照和减少苦草叶绿素a含量,导致苦草生物量减少.

  5. Allelopathy of decomposed maize straw products on three soil-born diseases of wheat and the analysis by GC-MS

    Institute of Scientific and Technical Information of China (English)

    QI Yong-zhi; ZHEN Wen-chao; LI Hai-yan

    2015-01-01

    In northern China, the soil-born diseases of wheat have been getting more and more serious under a new farming system that returns maize straw to the ifeld. In order to investigate the alelopathy of the decomposed maize straw products on three soil-born diseases of wheat, culture dish and pot experiments were conducted and the compounds in the products were identiifed by gas chromatography-mass spectrometry (GC-MS). Culture dish experiments showed that the mycelial growth, sclerotia formation amount and total weight ofRhizoctonia cerealiswere promoted at concentrations of 0.03, 0.06 and 0.12 g mL–1 and inhibited at concentration of 0.48 g mL–1 of the decomposed products. No signiifcant effects were found of the product concentrations on average weight of the sclerotia. Mycelial growth ofGaeumannomyces graminis was promoted at almost al concentrations except the highest one. Mycelial growth and spore germination ofBipolaris sorokiniana were signiifcantly inhibited by al concentrations of the decomposed products, with enhanced inhibition effects along with the increased concentrations. The length, number and dry weight of roots together with the root superoxide dismutase activity were promoted by the lowest concentration (0.03 g mL–1), with a synthetic effect index of 0.012, and inhibited by other concentrations. The ion leakage of roots was increased and the root peroxidase activity of roots was lowered by al the treatments. Pot experiments revealed that occurrence of the sharp eyespot was reduced by 0.03 and 0.06 g mL–1 of decomposed products after irrigation. However, the incidence rates and disease indexes were signiifcantly increased by 0.12, 0.24 and 0.48 g mL–1 of decomposed products. The results indicated that incidence rates and disease indexes of the take-al were signiifcantly promoted after being irrigated with the decomposed products, while occurrences of the common rot didn’t change, signiifcantly. GC-MS results showed that the compounds of the decomposed products included organic acids, esters, hydrocarbons, amides and aldehydes, with the proportions 25.26, 24.01, 17.22, 14.39 and 7.73%, respectively. Further analysis investigated that the alelochemicals identiifed in straw decomposed products contained p-hydroxybenzoic acid (9.21%), dibutyl phthalate (6.94%), 3-phenyl-2-acrylic (5.06%), 4-hydroxy-3,5-dimethoxybenzoic acid (2.26%), hexanoic acid (1.73%), 8-octadecenoic acid (1.06%), 3-(4-hydroxy-3-methoxy-phenyl)-2-propenoic acid (1.04%), 4-hydroxy-3-methoxy-benzoic acid (0.94%) and salicylic acid (0.94%).

  6. 人工群落中苗期紫茎泽兰的化感作用和对光环境的适应%Allelopathy and light acclimation characteristic for Ageratina adenophora seedlings grown in man-made communities

    Institute of Scientific and Technical Information of China (English)

    王俊峰; 冯玉龙

    2006-01-01

    在有、无活性炭的条件下分别构建紫茎泽兰(Ageratina adenophora)与4种受体植物--飞机草(Chromolaena odorata)、鬼针草(Bidens pilosa)、胜红蓟(Ageratum conyzoides)和兰花菊三七(Gynura sp.)混种的人工群落,研究了群落中紫茎泽兰的化感作用和对群落光环境的适应,探讨了化感作用和光适应特性与其入侵性的关系.结果表明,活性炭处理对4种受体植物的生长、生理特性影响不显著,说明苗期紫茎泽兰化感作用不明显,推测入侵初期化感作用不是紫茎泽兰排挤本地种的主要原因.4种受体植物可以通过化感作用对紫茎泽兰产生某些影响,但群落的光环境对其影响更大.紫茎泽兰能很好地适应群落中不同的光环境.苗期紫茎泽兰处于群落下层,叶片受光指数低,此时它能长期忍耐并缓慢生长;随着叶片受光指数的升高,其最大净光合速率、超氧化物歧化酶活性、叶绿素a/b比、总生物量、总叶面积、地茎、叶片数和分支数升高,比叶面积和比茎长降低,这有利于它维持叶片能量平衡并导致对邻近植物的严重遮荫.紫茎泽兰强的光适应能力、强光下对其它物种的遮荫效应与其入侵性密切相关.

  7. 小麦秸秆水浸提液对五种植物化感作用的研究%Allelopathy of wheat straw aqueous extract on five kinds of plants

    Institute of Scientific and Technical Information of China (English)

    郑曦; 杨茜茜; 李小花

    2016-01-01

    该文研究了不同浓度的小麦秸秆水浸提液对徐州地区2种玉米(郑单958和农大108)和3种常见玉米田间杂草(马唐、稗草和反枝苋)种子萌发和幼苗生长的影响。结果表明:当小麦秸秆浸提液浓度分别大于75、50和25 g•L-1时,马唐、稗草和反枝苋种子的萌发受到显著的抑制;当小麦秸秆浸提液浓度分别大于50和37.5 g•L-1时,玉米郑单958和农大108种子的萌发受到显著的抑制;但当小麦秸秆浸提液浓度大于37.5 g•L-1时,马唐、稗草和反枝苋幼苗根和芽的生长均受到明显的抑制;当小麦秸秆浸提液浓度小于75 g•L-1时,玉米郑单958和农大108幼苗根与芽的生长受到明显的促进,且郑单958幼苗叶片中叶绿素的含量以及郑单958的POD酶活性均得到提高。该研究结果表明较高浓度的小麦秸秆浸提液(50 g•L-1)会抑制杂草的生长,有利于玉米郑单958的生长,为小麦秸秆还田和玉米田杂草的生态防治提供了理论基础。%An experiment was carried out to explore effects of wheat straw aqueous extract on the seed germination and seedling growth of two kinds of maize ( Zhengdan 958 and Nongda 108) , large crabgrass ( Digitaria sanguinalis) , barn-yard grass (Echinochloa crusgalli) and redroot amaranth (Amaranthus retroflexus). The results showed that when the concentration of wheat straw aqueous extract was respective over 75, 50 and 37.5 g•L-1 , the seed germination rates of large crabgrass, barnyard grass and redroot amaranth were inhabited, while the concentration was over 50 and 37.5 g•L-1 , the seed germination rates of Zhengdan 958 and Nongda 108 were inhabited;but the root and shoot length of large crabgrass, barnyard grass and redroot amaranth decreased obviously when the extract concentration was over 37. 5 g•L-1;while the concentration of wheat straw aqueous extract was under 75 g•L-1 , the root and shoot length of these two kinds of maize were improved obviously, meanwhile the content of chlorophyll and the POD enzyme activity of maize ZD958 were enhanced, and the higher concentration of wheat straw aqueous extract (50 g•L-1) had an adverse impact on weeds growth, but it was good for the growth of maize Zhengdan 958.

  8. Allelopathy Effect of Wheat Root Aqueous Extracts on Different Vigna angularis Varieties%小麦根系水提液对不同基因型红小豆的化感效应

    Institute of Scientific and Technical Information of China (English)

    秦成; 裴红宾; 连慧达

    2014-01-01

    Objective] This study aimed to investigate the al elopathy effect on the seed germination and seedling growth of different adzuki bean (Vigna angularis) vari-eties in wheat root aqueous extracts. [Method] Culture dish method and pot experi-ment were carried out with the seeds and the seedling of 10 adzuki bean varieties, respectively, and seed germination rate and various indexes of the seedlings were measured. [Result] ① 30 g/L wheat root aqueous extracts very significantly im-proved the germination rate and sprouting index of B1789, Baihong 3, Baohong 947. ② The genotype differences of adzuki bean seedling was presented by the morphological index in wheat root aqueous extracts treatment; among al the mor-phological indexes, Baohong 947, Jinhong 3 presented a positive al elopathic effect, and their plant height, root length and leaf area were extremely significantly in-creased, while the fresh weights of both above-ground and underground parts were increased obviously, compared with the control. ③ According to the synthetical al-lelopathic indices, wheat root aqueous extracts had different degrees of promoting effects on the six adzuki bean varieties: Baohong 947>Baihong 6>B1789>Zunhua-hong>Jihong>Jinhong 3>Baohong 8824-17>Baihong 3. ④ Treated by wheat root aqueous extract, the SOD activity, POD activity, MDA content, TTC activity and chlorophyl content in the seedlings of adzuki beans of different genotypes changed by a smal er range in al elopathic promotion varieties than in al elopathic inhibition varieties. [Conclusion] The results proved that Baohong 947 is the best summer-planting variety after wheat.%[目的]研究小麦根系水提液对不同基因型红小豆种子萌发和幼苗生长的影响。[方法]以10个红小豆品种为试验材料,用培养皿测定种子萌发并采用盆栽培养幼苗,取样测定各项指标。[结果]①30 g/L小麦根系水提液处理极显著的提高了 B1789、白红3号、保红947的发芽率和发芽指数。②小麦根系水提液使红小豆幼苗的形态指标呈现不同的基因型差异,在测定的形态指标中,保红947、晋红3号呈现出积极的化感效应,与对照相比,极显著的促进了株高、根长的生长,叶面积增大、增加了地上部鲜重和地下部鲜重。③从化感效应综合指数来看,与对照相比,6个红小豆品种在小麦根系水提液下存在不同程度的促进作用,从高到低依次为:保红947>遵化红>B1789>冀红>晋红3号>保红8824-17>白红3号。④小麦根系水提液处理下,各基因型红小豆幼苗的 SOD活性、POD活性、MDA含量、TTC活力、叶绿素含量均呈现相似的规律:化感促进品种的变化幅度小,而化感抑制品种变化幅度大。[结论]保红947为小麦最佳的接茬品种。

  9. 外源酚酸对盆栽大豆苗期生长发育影响研究%Effects of Exogenous Phenolic Acids on Allelo-pathy of Potted Soybean Seedlings

    Institute of Scientific and Technical Information of China (English)

    陈龙; 张美玲; 辛明月; 李建东

    2015-01-01

    In this study, several general y reported exogenous phenolic acids were selected as regents for potting experiments, aiming at revealing the effects of differ-ent concentrations of exogenous phenolic acids on the growth and development of soybean seedlings. The growth and development indicators of soybean seedlings treated with five different concentrations of exogenous phenolic acids, such as plant height, leaf area, root nodule number and root-shoot ratio, were determined and compared. According to the experimental results, three exogenous phenolic acids with different concentrations exhibited slight effects on plant height of potted soy-bean seedlings. The leaf area of potted soybean seedlings treated with 1.0 g/kg benzoic acid and cinnamic acid varied extremely significantly compared with the control. Root nodule number of potted soybean seedlings treated with 1.0 g/kg ben-zoic acid and vanil ic acid increased remarkably, but 1.0 g/kg cinnamic acid had lit-tle effects on root nodule number. When the concentration of phenolic acids was 1.0 g/kg, three phenolic acids exhibited the maximum effects on root-shoot ratio of potted soybean seedlings. Overal , low concentrations of exogenous phenolic acids exhibited no significant effects on the growth and development of potted soybean seedlings; high concentrations of exogenous phenolic acids inhibited the growth and development of potted soybean shoots, increased root nodule number and improved root-shoot ratio.%以普遍报道的几种外源酚酸为试剂,通过盆栽实验,旨在探讨不同浓度外源酚酸对苗期大豆生长发育的影响。通过设置5种不同浓度外源酚酸的盆栽试验,测定不同浓度外源酚酸对盆栽大豆苗期生长发育指标影响。结果表明不同浓度3种外源酚酸对苗期大豆株高的影响总体较小。1.09 g/kg苯甲酸处理和肉桂处理的苗期大豆叶面积与对照差异达到极显著水平。1.09 g/kg苯甲酸处理和香草酸处理均显著增加了盆栽大豆根瘤数,肉桂酸影响较小。1.09 g/kg不同浓度3种酚酸对盆栽大豆根冠比影响最大。总体上,低浓度外源酚酸对盆栽大豆生长发育影响效果不显著;高浓度外源酚酸抑制了盆栽大豆地上部分生长发育,增加了盆栽大豆根瘤数和提高了盆栽大豆根冠比。

  10. Allelopathy of Parthenium hysterophorus L.Flowers on Abutilon theophrasti Medic.and Echinochloa crusgalli (L.) Beauv%银胶菊花对苘麻和稗的化感作用

    Institute of Scientific and Technical Information of China (English)

    陈业兵; 邓立刚; 李增梅; 董崭; 刘伟堂

    2014-01-01

    通过室内培养皿法,研究了银胶菊花水浸提液及其乙酸乙酯相、正丁醇相、剩余水相不同极性组分对苘麻和稗种子萌发及幼苗生长的影响。定性测定结果表明,在50 g/L浓度处理下,水浸提液完全抑制苘麻和稗种子萌发,对苘麻和稗根长、芽长、鲜重抑制率分别为82.6%、89.1%、84.3%和91.7%、55.8%、39.1%;正丁醇相抑制苘麻种子萌发和幼苗生长最强,乙酸乙酯相抑制稗种子萌发和幼苗生长最强。定量测定结果表明,在1g/L浓度处理下,乙酸乙酯相生物活性最高,苘麻和稗种子萌发率分别为13.3%和33.3%,对苘麻和稗根长、芽长、鲜重的抑制率分别为63.1%、80.0%、58.3%和51.3%、26.7%、23.3%。%The allelopathic effect of a Parthenium yh sterophorus L.flower aqueous extract and its ethyl acetate,n-buta-nol,and residual water fractions on seed germination and seedling growth of Abutilon theophrasti Medic.and Echinochloa crusgalli ( L.) Beauv.were studied by petri dish bioassays.Seeds of A.theophrasti and E.crusgalli failed to germinate in an aqueous extract of 50 g/L;the inhibition rate of root growth,shoot growth and fresh weight were 82.6%,89.1%and 84.3%for A.theophrasti,respectively and 91.7%,55.8%and 39.1% for E.crusgalli,respectively.With the butanol extract (50 g/L) the inhibition of root growth,shoot growth and fresh weight were 63.1%,80.0% and 58.3% for A. theophrasti,respectively,and 51.3%,26.7%and 23.3%for E.crusgalli,respectively.The germination rate of A.theo-phrasti and E.crusgalli were 13.3%and 33.3%,respectively.

  11. 大叶芥菜对牛膝菊的化感作用潜力%Allelopathy of Brassica juncea var.foliosa L.H. Bailey on Galinsoga parviflora Cav

    Institute of Scientific and Technical Information of China (English)

    朱峰; 何永福; 叶照春

    2015-01-01

    以牛膝菊为受体,研究大叶芥菜水浸提液对牛膝菊的化感作用。结果显示,浓度分别为0.25000、0.12500、0.06250、0.03125 g/mL 的大叶芥菜水浸提液对牛膝菊种子的萌发抑制效应以0.25000 g/mL 最高,平均抑制率为56.03%;低浓度(0.03125 g/mL)处理对牛膝菊种子萌发基本上没有抑制作用。此外研究发现,大叶芥菜水浸提液对牛膝菊胚根、胚芽的萌发和鲜质量积累都有明显的抑制作用,对鲜质量平均抑制率分别为75.75%、35.82%、17.48%、18.81%;对牛膝菊种子萌发、胚根、胚芽、鲜质量的化感综合效应分别为60.36%、30.45%、14.23%、16.50%。结果表明,大叶芥菜对牛膝菊有很强的化感潜力,能为牛膝菊的绿色防控提供理论依据。%Galinsoga parviflora Cav.was used as a receptor to evaluate the allelopathic effects of water extracts of Brassica juncea var.foliosa L.H.Bailey.Of the concentrations tested (31.2,62.5,125 and 250 mg/mL),the highest one, 250 mg/mL was the most inhibitory (56%) of G.parviflora seed germination whereas the lowest concentration (31.2 mg/mL)did not affect germination.The water extracts of B.juncea var.foliosa inhibited growth of radicle and seedling,the inhibition rates were 76%,36%,17%,19%,respectively;the overall allelopathic effect on the seed germi-nation,growth of radicle and seedling,and fresh weight of G.parviflora were 60%,30%,14%,16%,respectively.In conclusion,B.juncea var.foliosa has strong allelopathic effects on G.parviflora,a property that can serve as the basis for the green control of this weed.

  12. Alelopatia de extratos voláteis na germinação de sementes e no comprimento da raiz de alface Allelopathy of plant volatile extracts on seed germination and radicle length of lettuce

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Sampaio Alves

    2004-11-01

    Full Text Available O objetivo deste trabalho foi identificar possíveis efeitos alelopáticos de extratos voláteis de óleos essenciais na germinação e no comprimento da raiz de plântulas de alface. Foram utilizadas cinco concentrações de cada óleo (0,0, 0,001, 0,01, 0,1 e 1,0%, v/v, em delineamento inteiramente casualizado, com quatro repetições de 25 sementes de alface. Os extratos voláteis de óleos essenciais de canela, alecrim-pimenta, capim-citronela e alfavaca-cravo evidenciaram potencialidades alelopáticas na germinação e comprimento das raízes de plântulas de alface, efeitos que variaram de acordo com a concentração do óleo. O extrato volátil de óleo de jaborandi estimula o crescimento da radícula e não provoca inibição da germinação de sementes de alface, caracterizando-se como de efeito alelopático benéfico.The objective of this work was to identify allelopathic effects of volatile extracts of essential oils on germination and radicle length of lettuce seedlings. Five concentrations were utilized for each oil (0.0, 0.001, 0.01, 0.1 and 1.0%, v/v arranged into a completely randomized design with four replicates of 25 seeds. The volatile extracts of essential oils of cinnamon, alecrim-pimenta, capim-citronela and alfavaca-cravo revealed allelopathic potentialities on lettuce seed germination and radicle growth, effect which varied according to the oil concentration. The volatile extract of Jaborandi essential oil stimulates radicle growth and does not inhibit lettuce seeds germination, which is characterized as a beneficial allelopathic effect.

  13. 广藿香根系分泌物的化感自毒作用研究%Study on the Allelopathy and the Autotoxicity of Patchouli Root Exudates

    Institute of Scientific and Technical Information of China (English)

    李玲梅; 李明

    2011-01-01

    以组培苗为材料,应用组织培养技术分析广藿香根系分泌物对萝卜、广金钱草和广藿香组培苗生长的影响.结果表明,广藿香根系分泌物抑制广藿香组培苗和广金钱草的生长;低浓度能促进萝卜生长,高浓度抑制其生长.根系分泌物对广藿香的不利影响随浓度的增加而增大,表明根系分泌物可能是导致广藿香连作障碍的主要原因之一.%The effect of root exudates on the growth of radish, Desmodium styracifoliurn and patchouli tissue culture were analyzed using tissue culture method. Results showed that root exudates of patchouli inhibited the growth of the patchouli tissue culture and Desmodium styracifoliurn;The low concentration of root exudates promoted the growth of the radish, the high concentration of root exudates inhibited the growth of the radish. The greater concentration of root exudates in the medium,the more adverse effect it had on the plants.It is concluded that root exudates of patchouli was one of the important factors inducing continuous cropping obstacle in patchouli.

  14. Alelopatia de Baccharis dracunculifolia DC. sobre a germinação e desenvolvimento de espécies cultivadas = Allelopathy of Baccharis dracunculifolia DC. on the germination and development of cultivated species

    Directory of Open Access Journals (Sweden)

    Grasielle Soares Gusman

    2008-04-01

    Full Text Available Metabótitos secundários produzidos em algumas plantas podem provocaralterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. O objetivo deste trabalho foi identificar possíveis efeitos alelopáticos de extratos aquosos de folhas de Baccharis dracunculifolia na germinação e no crescimento de plântulas de Brassica campestris, B. oleracea cv. Capitata, Citrullus lanatus, Eruca sativa, Lactuca sativa cv. Branca Boston, L. sativa cv. Grand Rapids, L. sativa cv. Simpson, Lycopersicum esculentum, Raphanussativus e Zea mays L. Para a obtenção do extrato aquoso, foram utilizadas folhas previamente secas na concentração de 1 g 10 mL-1 (p/v e utilizadas sete concentrações deste extrato aquoso (100, 90, 70, 50, 30, 10 e 0%, em delineamento inteiramente casualizado, com cinco repetições de dez sementes das espécies cultivadas. Os extratos aquosos de B. dracunculifolia evidenciaram potencialidades alelopáticas sobre a germinação das sementes e no crescimento da parte aérea e do sistema radicular de todas espécies testadas, sendo que a redução na germinação e no crescimento inicial elevaram-se com o aumento das concentrações dos extratos aquosos utilizados. Os resultados indicam a existência de potencial alelopático de B. dracunculifolia.Secondary metabolites produced in some plant species can cause developmental changes in other plants or even in other organisms. Theobjective of this work was to identify the possible allelopathic effects of the aqueous extracts of Baccharis dracunculifolia leaves in the germination and growth of seedlings of Brassica campestris, B. oleracea cv. Capitata, Citrullus lanatus, Eruca sativa, Lactuca sativa cv. Branca Boston, L. sativa cv. Grand Rapids, L. sativa cv. Simpson, Lycopersicum esculentum, Raphanus sativus and Zea mays. The aqueous extracts were made out of dried leaves at 1g 10mL-1 (p/vconcentration and by using seven of those aqueous extract concentrations (100, 90, 70, 50, 30, 10 and 0%, arranged into a completely randomized design, with five repetitions of ten seeds of each cultivated species. The aqueous extracts of B. dracunculifolia revealed allelopathic potential in the germination of seeds and in the growth of the aerial part of the root system in all tested species, while the reduction in germination and initial growthintensified with the increase in the concentrations of the aqueous extracts used. The results indicate the existence of allelopathic potential in B. dracunculifolia.

  15. 不同发育期反枝苋对黄瓜根缘细胞的化感作用%The allelopathy of different development stages of Amaranthus retroflexus L.on root border cells of cucumber

    Institute of Scientific and Technical Information of China (English)

    刘爽; 马丹炜

    2009-01-01

    以黄瓜为实验材料,采用悬空气培养法研究了不同发育期反枝苋水浸提液对根缘细胞的化感效应.结果表明:在反枝苋水浸提液作用下,黄瓜根果胶甲基酯酶(PME)活性升高,但随着水浸提液浓度的升高,这种促进效应逐渐降低;而黄瓜根缘细胞存活率随着水浸提液浓度的升高而下降.相同发育期反枝苋不同部位的化感作用差异不显著,不同发育时期反枝苋化感作用差异较为明显,其化感作用以幼苗期最强,现蕾期次之,成熟期最弱.推测化感作用是反枝苋发育初期取得竞争优势,迅速占领生态位的原因之一.

  16. Estudo fitoquímico de folhas de Solanum lycocarpum A. St.-Hil (Solanaceae e sua aplicação na alelopatia Phytochemistry of Solanum lycocarpum A.St.-Hil (Solanaceae leaves and their application in allelopathy

    Directory of Open Access Journals (Sweden)

    Sarah Christina Caldas Oliveira

    2012-09-01

    Full Text Available Solanum lycocarpum A.St.-Hil (Solanaceae é um arbusto típico da região central do Brasil (Cerrado. A atividade alelopática do extrato aquoso de folhas e frutos dessa espécie já foi verificada em estudos anteriores. O objetivo desse trabalho foi avaliar a atividade alelopática de diferentes extratos de S. lycocarpum na germinação e crescimento de quatro espécies-alvo. As folhas foram coletadas, secas e trituradas e submetidas a dois métodos distintos de extração: 1- líquido-líquido (acetato de etila e diclorometano do extrato aquoso das folhas e 2- com solventes em polaridade crescente (hexano, diclorometano, acetato de etila, acetona, metanol e água diretamente das folhas. Cada extração foi realizada com equipamento de ultrassom durante uma hora, filtrado e evaporado. Desses extratos, soluções de 800, 400 e 200 ppm foram preparadas, e água e Logran® foram usados como controle positivo e negativo, respectivamente. Cada solução, bem como os controles, foi dissolvida em DMSO para os bioensaios. As espécies alvo usadas foram: alface, agrião, tomate e cebola. Cada placa era composta de 20 sementes e foi adicionado 1 mL de solução teste com 4 repetições. As placas foram incubadas a 25 ºC no escuro. Posteriormente, as plântulas tiveram suas partes aéreas e raízes medidas e a porcentagem de germinação e inibição calculada para cada extrato. Tomate foi a espécie que mostrou maior sensibilidade para todos os extratos, seguido de agrião, cebola e alface. Os extratos que tiveram maior atividade foram o acetato de etila, acetona e as extrações líquido-líquido, indicando as frações que devem conter os princípios ativos da folha dessa espécie.Solanum lycocarpum A.St.-Hil (Solanaceae is a typical shrub in the Cerrado of central Brazil. The allelopathic activity of aqueous extracts of the leaves and fruits of this species has already been proven in previous studies. The goal of this work was to verify the allelopathic activity of different leaf extracts of S. lycocarpum on the germination and growth of four target species. The leaves were collected, dried, triturated and submitted to two distinct methods of extraction: 1- liquid-liquid (ethyl acetate and dichloromethane from the aqueous extract and 2- with solvents of increasing polarities (hexane, dichloromethane, ethyl acetate, acetone, methanol and water directly from the leaves. Each extraction was made with ultrasound equipment for one hour, filtered and evaporated. From these extracts, solutions of 800, 400 and 200 ppm were prepared, and water and Logran® were used as positive and negative controls, respectively. Each solution, as well as the controls, was dissolved in DMSO for the bioassays. The target species used were lettuce, watercress, tomato and onion. To each plate, 20 seeds were added and 1 mL of the tested solutions (with 4 repetitions. The plates were incubated at 25 ºC without light, and the shoots and roots of the seedlings were then measured and the percentage of germination and the inhibition of each extract were calculated. Tomato was the most sensitive to the extracts, followed by watercress, onion and lettuce. The extracts with stronger activity were AcOEt, acetone and the liquid-liquid extraction, indicating the fractions that may contain the active principles of the leaves in this species.

  17. Allelopathy Effects of Straw and Green Manure on Lettuce Seed%秸秆及绿肥浸提液对莴苣种子的化感作用

    Institute of Scientific and Technical Information of China (English)

    魏云霞; 鲁剑巍; 李小坤; 薛欣欣; 王素萍

    2013-01-01

    采用室内培养试验,通过测定稻草、油菜秸秆、紫云英及紫云英+油菜浸提液对莴苣种子发芽及幼苗生长的影响,研究秸秆及绿肥浸提液对莴苣种子的化感作用.结果表明:各秸秆及绿肥浸提液处理均会延迟莴苣种子的发芽速度,且高浓度抑制种子萌发;各浸提液处理对莴苣幼苗苗高表现为低促高抑,而对根长表现为抑制;莴苣幼苗鲜质量及于质量均随各浸提液浓度的增加先增加后降低,其中稻草、油菜秸秆、紫云英及紫云英+油菜浸提液对幼苗鲜质量的最大促进作用分别为27.33%、27.52%、1.28%、19.24%;不同浓度下,稻草、紫云英浸提液对莴苣的化感综合效应为抑制,油菜秸秆及紫云英+油菜为低促高抑;紫云英与油菜混合可作为改善紫云英、油菜单独使用效果的有效途径.%An experiment was conducted by indoor culture to study the allelopathic effects of straw and green manure on lettuce (Lactuca satiua L. ) germination and seedling growth. Results showed that straw and green manure extracts treatments could delay the progress of germination, even inhibit the germination rate at high concentration. In this study, low concentration of all extract treatments intensified the inhibit for seedling height, while for the root length they only expressed as normal inhibit. The fresh weight and dry weight reduced of lettuce seedlings increased as the concentration of extract treatments increased, then decreased afterwards. The extracts of rice straw, rape stalk, Chinese milk vetch and Chinese milk vetch mixed with rape stalk at different concentrations increased the seedling fresh weight by 27.33%, 27.52%, 1.28%, 19.24%, respectively. Under different concentrations, extracts of rice straw and Chinese milk vetch showed inhibit allelopathic effect on lettuce, while that of rape stalk and Chinese milk vetch mixed with rape stalk showed promotion allelopathic effect at low concentration. The mixture of Chinese milk vetch and rape stalk maybe an effective way to improve the effectiveness of Chinese milk vetch or rape stalk used alone.

  18. QTL Information Table: 417 [Q-TARO

    Lifescience Database Archive (English)

    Full Text Available Others Others allelopathy RFLP C)Interval RIL Zhong 156 Gumei 2 RZ395 RZ264 pha Xu,... Z., He, Y., Cui, S., Zhao, M., Zhang, X., and Li, D. (2003). Genes mapping on rice allelopathy against barnyardgrass. Ying Yong Sheng Tai Xue Bao 14, 2258-2260. ...

  19. Mechanism and active variety of allelochemicals

    Science.gov (United States)

    Peng, S.-L.; Wen, J.; Guo, Q.-F.

    2004-01-01

    This article summarizes allelochemicals' active variety, its potential causes and function mechanisms. Allelochemicals' activity varies with temperature, photoperiod, water and soils during natural processes, with its initial concentration, compound structure and mixed degree during functional processes, with plant accessions, tissues and maturity within-species, and with research techniques and operation processes. The prospective developmental aspects of allelopathy studies in the future are discussed. Future research should focus on: (1) to identify and purify allelochemicals more effectively, especially for agriculture, (2) the functions of allelopathy at the molecular structure level, (3) using allelopathy to explain plant species interactions, (4) allelopathy as a driving force of succession, and (5) the significance of allelopathy in the evolutionary processes.

  20. 杂草科学管理——理论基础与实施途径%Scientific Management of Weed:Theory and Implementation

    Institute of Scientific and Technical Information of China (English)

    涂修亮; 陈英明

    2002-01-01

    Scientific management of weeds is theoretically based on ecology.The implementation methods inclade:Intensifying the weed biology and ecology research, especially those of the heavy weeds;Intensifying the research of developing competition between the crop and the weed;Utilizing a allelopathy the gene engineering and breeding against the weeds;Utilizing allelopathy between the crop and the weed, and utilizing biological and agricultural measurements to control the weeds.

  1. Allelopathic interactions between the brown algal genus Lobophora (Dictyotales, Phaeophyceae) and scleractinian corals

    OpenAIRE

    Vieira, C; Thomas, O. P.; Culioli, G.; Genta-Jouve, G.; Houlbreque, F.; Gaubert, J.; De Clerck, O.; Payri, C.E.

    2016-01-01

    Allelopathy has been recently suggested as a mechanism by which macroalgae may outcompete corals in damaged reefs. Members of the brown algal genus Lobophora are commonly observed in close contact with scleractinian corals and have been considered responsible for negative effects of macroalgae to scleractinian corals. Recent field assays have suggested the potential role of chemical mediators in this interaction. We performed in situ bioassays testing the allelopathy of crude extracts and iso...

  2. Allelopathic interactions between the brown algal genus Lobophora (Dictyotales, Phaeophyceae) and scleractinian corals

    OpenAIRE

    Christophe Vieira; Thomas, Olivier P.; Gérald Culioli; Grégory Genta-Jouve; Fanny Houlbreque; Julie Gaubert; Olivier De Clerck; Payri, Claude E

    2016-01-01

    International audience Allelopathy has been recently suggested as a mechanism by which macroalgae may outcompete corals in damaged reefs. Members of the brown algal genus Lobophora are commonly observed in close contact with scleractinian corals and have been considered responsible for negative effects of macroalgae to scleractinian corals. Recent field assays have suggested the potential role of chemical mediators in this interaction. We performed in situ bioassays testing the allelopathy...

  3. 河西灌区3种主要农田杂草间的化感拮抗作用对小麦苗期生长发育的影响%The Susceptible Effect of the Allelopathy among Three Main Farmland Weeds in West Irrigated Area of Gansu on Growth and Development of Wheat

    Institute of Scientific and Technical Information of China (English)

    叶春雷; 崔文娟; 罗俊杰; 欧巧明

    2013-01-01

    The effects of antagonism among three kinds of weed (Artemisia annua,Datura stramonium,and Amaranthus retroflexus) on growth of wheat seedlings were studied.The results showed that:with the treatment times of weed extracts to wheat from one to three,the cumulative effect of the antagonism effect of weeds extracts on wheat growth was significantly inhibited.When the concentration of water extract of Artemisia annua was 0.3g/mL,the antagonism between Datura stramonium extract and Amaranthus retroflexus extract were strong,showing that effect promote wheat growth;When the concentration of Datura stramonium extract 0.1 ~ 0.3g/mL,the antagonistic effect between Artemisia annua extract and Amaranthus retroflexus extract was weak,showing weak effects on wheat growth promotion;When the concentration of Amaranthus retroflexus 0.5g/mL the antagonism between Artemisia annua extract and Datura stramonium was weak,the performance of growth-promoting role for wheat is weak.%比较研究了3种麦田杂草黄花蒿(Artemisia annuaL.)、曼陀罗(Datura stramonium L.)和反枝苋(Amaranthus retroflexusL.)彼此间的 拮抗作用对小麦幼苗生长的影响,结果表明:随杂草浸提液对小麦处理1次到3次的过程,杂草浸提液间的拮抗作用对小麦生长抑制作用累积效应明显;当黄花蒿浸提液浓度为0.3g/mL时,曼陀罗浸提液与反枝苋浸提液之间存在较强的拮抗作用,表现为对小麦生长促进作用明显;当曼陀罗浸提液浓度为0.1~0.3g/mL时,黄花蒿浸提液与反枝苋浸提液之间存在较弱的拮抗作用,表现为对小麦生长促进作用较弱;当反枝苋浸提液浓度为0.5g/mL时,黄花蒿与曼陀罗之间存在较弱的拮抗作用,表现为对小麦生长促进作用较弱.

  4. Effects of allelopathy of Ulva pertusa Kjellm on growth and antioxidant enzymatic activies of Heterosigma akashiwo (Hada) Hada%孔石莼克生作用对赤潮异弯藻生长和抗氧化系统活性的影响

    Institute of Scientific and Technical Information of China (English)

    蔡恒江; 李博; 孙禾琳

    2010-01-01

    通过实验生态学和生物化学的方法,研究了孔石莼(Ulva pertusa Kjellman)克生作用对赤潮异弯藻[Heterosigma akashiwo(nada)Hada]生长及其叶绿素a(Chl-a)含量、可溶性蛋白含量、丙二醛(MDA)含量、总抗氧化能力(T-AOC)、过氧化氢酶(CAT)活力、超氧化物歧化酶(SOD)活力和谷胱甘肽过氧化酶(GPX)活力的影响.结果表明:孔石莼的克生作用会明显抑制赤潮异弯藻的生长,且赤潮异弯藻抗氧化系统活性对其有明显的响应.克生作用会使T-AOC和SOD活力呈现降低的趋势;MDA含量和CAT活力呈现升高的趋势;GPX活力呈现先升高而后下降趋势;Chl-a含量和可溶性蛋白含量并无明显变化.推测孔石莼克生作用诱导赤潮异弯藻产生活性氧自由基,是藻体受损伤的主要原因.

  5. ESTUDIO DE PREFORMULACIÓN PARA EL DESARROLLO DE UN GEL A BASE DE POLÍMEROS CON CAPACIDAD MUCOADHESIVA PARA ENSAYOS DE ALELOPATÍA EN INVERTEBRADOS MARINOS. Preformulation study for the development of a polymer-based gel with mucoadhesive propierties for its use in allelopathy assays in marine invertebrates

    Directory of Open Access Journals (Sweden)

    Jenny Patricia Andrade

    Full Text Available La investigación se desarrolló con el fin de implementar una metodología que permitiera la realización de ensayos de interacciones alelopáticas entre corales y esponjas, minimizando la interacción física provocada por el uso de dispositivos que producen roce y efecto abrasivo sobre los pólipos del coral. Se llevó a cabo un estudio de preformulación utilizando polímeros con características mucoadhesivas sobre mucus que recubre los pólipos de coral, con el fin de obtener un gel, incorporando en las formulaciones un extracto de la esponja Cliona delitrix. Se caracterizaron propiedades como extensibilidad y adherencia, así como la capacidad bioadhesiva de las formulaciones propuestas, considerando su comportamiento reológico. Estas mostraron una buena estabilidad física frente a las condiciones del medio marino tanto in vitro como in situ. De igual manera, se diseñó un dispositivo que facilitó la aplicación del gel sobre la superficie de los corales por parte de los buzos en el arrecife coralino. Finalmente se estudió el comportamiento de liberación al medio acuoso simulado del gel con el extracto de la esponja objeto de estudioThis study was carried out with the purpose of implementing a methodology to assess allelopathic interactions assays between corals and reef sponges reducing the physical interaction caused by the use of devices that involve abrasion and harm over the coral polyps. Was carried out a preformulation study using polymers with mucoadhesive on the mucus that cover the coral polyps, with the purpose of develop a gel, incorporating an extract from Cliona Delitrix into the formulations. Obtained formulations were characterized by properties such as extensibility, adherence and mucoadhesive capacity. These formulations showed great physical stability under prevalent marine conditions both in vitro and in situ. In the same way was designed a device that let the smearing of the gel over the coral surfaces carried out for the divers in the coral reefs. Finally, was studied the releasing behavior of the gel with the sponge´s extract into the sea water conditions

  6. 大型海藻内共生真菌次生代谢产物中抑制水华蓝藻物质的分离与活性%Identification of Compounds with Allelopathy on Bloom Microalgae from the Secondary Metabolites of Endophytic Fungi Isolated from Marine Macroalgae and the Algicidal Activities

    Institute of Scientific and Technical Information of China (English)

    左进城; 苗凤萍; 王爱云; 胡德昌

    2014-01-01

    为获得能明显抑制水华蓝藻的化感物质,本研究从28株大型海藻内共生真菌中筛选出了4株菌株,其粗提物能显著抑制水华鱼腥藻(Anabaena flos-aquae)和铜绿微囊藻(Microcystis aeruginosa)的生长.对这4株真菌扩大培养后,检测了从其次生代谢产物中分离出的32种单体化合物的抑藻活性.其中,化合物sterigmatocystin、(2'E,4'E,6'E)-6-(1'-carboxyocta-2',4',6'-triene)-11,12-epoxy-9,11-dihydroxydrim-7-ene、6,8-di-O-methylnidurufin和aversin对水华鱼腥藻的抑制率显著大于50%(P<0.05),24 h半数有效浓度(EC50,24h)分别为6.865、4.302、1.824、2.319 μg/mL;化合物sterigmatocystin、indol-3-carboxaldehyde和(2'E,4'E,6'E)-6-(1'-carboxyocta-2',4',6'-triene)-11,12-epoxy-9,11-dihydroxydrim-7-ene对铜绿微囊藻的抑制率显著大于50%(P<0.05),EC50,24h分别为4.167、5.374、8.386 μg/mL.

  7. Estudo fitoquímico e avaliação alelopática de Memora peregrina - "ciganinha" - Bignoniaceae, uma espécie invasora de pastagens em Mato Grosso do Sul Phytochemical study and evaluation of allelopathy in Memora peregrina, 'ciganinha', Bignoniaceae, an invading species in pastures in Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Rafaela Ferreira Grassi

    2005-03-01

    Full Text Available Memora peregrina (local name: 'ciganinha' - Bignoniaceae is a weed that often invades pastures in the Brazilian state of Mato Grosso do Sul. From its leaves and subterranean parts, the following compounds were isolated: allantoin (20.7 w/w in subterranean parts, the iridoid 6beta-hydroxyipolamiide, hyperin, 3'-O-methylhyperin, 4-hydroxy-N-methylproline, beta-sitosterol, alpha-amirin and beta-amirin, and lupeol. Allantoin exhibited an activity of inducing germination in seeds of Lactuca sativa used as a biological model, and the iridoid showed moderate activity in the larval development of Anagasta kuehniella. These results, associated with this plant's behavior, are suggestive of the occurrence of adaptive and competitive strategies in relation to other plant species.

  8. 向日葵水提液对马齿苋种子萌发及幼苗生长的化感作用%Allelopathy Effect of Sunflower Water Extracts on Germination and Growth of Portulaca oleracea L.Seeds

    Institute of Scientific and Technical Information of China (English)

    胡云; 刁锐琦; 胡涛

    2014-01-01

    [目的]探索向日葵不同部位水提液对马齿苋种子萌发及幼苗生长的化感作用.[方法]以发芽势、发芽率、芽长、根长和化感效应指数等作为测量指标,研究了向日葵不同部位的水提取液对马齿苋种子萌发及幼苗生长的化感作用.[结果]向日葵不同部位对马齿苋种子萌发及幼苗生长存在化感作用,且化感作用为抑制作用,其大小依次为茎、花、叶、根;不同部位水提液对马齿苋的抑制作用随着浓度的增大而增大.[结论]为农业综合防治及生产提供了理论依据.

  9. Alelopatia de Baccharis dracunculifolia DC. sobre a germinação e desenvolvimento de espécies cultivadas - DOI: 10.4025/actascibiolsci.v30i2.3592 Allelopathy of Baccharis dracunculifolia DC. on the germination and development of cultivated species - DOI: 10.4025/actascibiolsci.v30i3.3592

    Directory of Open Access Journals (Sweden)

    Alexandre Horácio Couto Bittencourt

    2008-05-01

    Full Text Available Metabótitos secundários produzidos em algumas plantas podem provocar alterações no desenvolvimento de outras plantas ou até mesmo de outros organismos. O objetivo deste trabalho foi identificar possíveis efeitos alelopáticos de extratos aquosos de folhas de Baccharis dracunculifolia na germinação e no crescimento de plântulas de Brassica campestris, B. oleracea cv. Capitata, Citrullus lanatus, Eruca sativa, Lactuca sativa cv. Branca Boston, L. sativa cv. Grand Rapids, L. sativa cv. Simpson, Lycopersicum esculentum, Raphanus sativus e Zea mays L. Para a obtenção do extrato aquoso, foram utilizadas folhas previamente secas na concentração de 1 g 10 mL-1 (p/v e utilizadas sete concentrações deste extrato aquoso (100, 90, 70, 50, 30, 10 e 0%, em delineamento inteiramente casualizado, com cinco repetições de dez sementes das espécies cultivadas. Os extratos aquosos de B. dracunculifolia evidenciaram potencialidades alelopáticas sobre a germinação das sementes e no crescimento da parte aérea e do sistema radicular de todas espécies testadas, sendo que a redução na germinação e no crescimento inicial elevaram-se com o aumento das concentrações dos extratos aquosos utilizados. Os resultados indicam a existência de potencial alelopático de B. dracunculifolia.Secondary metabolites produced in some plant species can provoke development changes in other plants or even in other organisms. The objective of this work was to identify the possible allelopathic effects of the aqueous extracts of Baccharis dracunculifolia leaves in the germination and growth of Brassica campestris, B. oleracea cv. Capitata, Citrullus lanatus, Eruca sativa, Lactuca sativa cv. Branca Boston, L. sativa cv. Grand Rapids, L. sativa cv. Simpson, Lycopersicum esculentum, Raphanus sativus and Zea mays seedlings. The aqueous extracts were made out of dried leaves at a 1g 10 mL-1 (p/v concentration and by using seven of those aqueous extract concentrations (100, 90, 70, 50, 30, 10 and 0%, arranged into a completely randomized design, with five repetitions of ten seeds of each cultivated species. The aqueous extracts of B. dracunculifolia revealed allelopathic potentialities on the germination of the seeds and in the growth of the aerial part of the root system in all tested species and the reduction in the germination and in the initial growth increased with the increase of the concentrations of the used aqueous extracts. The results indicate the existence of allelopathic potential in B. dracunculifolia.

  10. 玉米秸秆腐解液中酚酸的检测及对小麦土传病原菌的化感作用%Determination of Phenolic Acids in Decomposing Products of Maize Straw and their Allelopathy on Pathogens of Wheat Soil-borne Disease

    Institute of Scientific and Technical Information of China (English)

    梁春启; 甄文超; 张承胤; 尹宝重

    2009-01-01

    在不同时期提取玉米秸秆腐解液,利用高效液相色谱检测其中酚酸类物质及其含量,并测定检测到的不同酚酸类物质对小麦土传病原菌孢子萌发和茵丝生长的影响率.结果表明,在玉米秸秆腐解液中共检测到5种酚酸类物质.不同时期提取的腐解液中酚酸类物质的种类和含量有所不同,其中在同期腐解液中邻苯二甲酸和苯甲酸含量明显高于其它3种酚酸:5种酚酸类物质对3种病原茵的茵丝生长及对禾顶囊壳小麦变种(Gaeumannomyces graminis var.tritici)和平脐蠕孢茵(Bipolaris sorokiniana(Sacc.)Shoem.)的孢子萌发具有不同程度的促进或抑制作用,且随着浓度的增高而作用趋势增强.

  11. Potenciação alelopática de extratos vegetais na germinação e no crescimento inicial de picão-preto e alface Allelopathy of plant extracts on germination and initial growth of beggartick (Bidens pilosa L.) and lettuce (Lactuca sativa L.)

    OpenAIRE

    Magda Cristiani Ferreira; José Roberto Pinto de Souza; Terezinha de Jesus Faria

    2007-01-01

    O picão-preto (Bidens pilosa L.) é uma planta daninha muito agressiva, que está presente em quase todo Brasil. O principal método de controle é o químico, porém apresenta elevado impacto ambiental, risco de intoxicação humana e possibilidade de causar fitotoxicidade as culturas. O objetivo do trabalho foi avaliar o efeito alelopático de extratos etanólicos de Eucalyptus citriodora Hook. e Pinus elliottii L. na germinação e no crescimento inicial de picão-preto e alface (Lactuca sativa L.). Fo...

  12. Variação sazonal na alelopatia de extratos aquosos de Coleus barbatus (A. Benth. sobre a germinação e o desenvolvimento de Lactuca sativa L. Seasonal variation in the allelopathy of aqueous extracts from Coleus barbatus (A. Benth. on the germination and development of Lactuca sativa L.

    Directory of Open Access Journals (Sweden)

    L.L. Pelegrini

    2012-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito alelopático de extratos de Coleus barbatus sobre a germinação e desenvolvimento de plântulas de alface. Os experimentos foram conduzidos em laboratório, em diferentes concentrações de extratos obtidos de folhas de falso-boldo (0; 7,5; 15; 22,5; 30%, coletadas nas quatro estações do ano, obtidos por trituração, maceração, infusão e decocção. As sementes de alface foram distribuídas sobre placas de petri umidecidas com 10 mL de solução. Os resultados mostraram que os extratos de folhas afetaram a germinabilidade de sementes de alface apenas na concentração de 30% do extrato preparado por decocção de folhas coletadas no inverno. O índice de velocidade de germinação apresentou redução significativa nos extratos triturados preparados no outono e inverno; na maceração de folhas coletadas no verão e outono e no extrato de decocção preparado no inverno. Os extratos estimularam o crescimento da parte aérea das plântulas de alface, ao passo que, o comprimento das raízes foi afetado pelos extratos, ora inibindo, ora estimulando o crescimento das mesmas. Os extratos de folhas de falso-boldo coletadas nas quatro estações do ano apresentaram efeito alelopático sobre a germinação e o desenvolvimento da alface, sendo que estes variaram em função da sazonalidade da coleta, da forma de obtenção dos extratos e das concentrações testadas.The aim of this study was to evaluate the allelopathic effects of extracts from Coleus barbatus on germination and seedling growth of lettuce. The experiments were conducted in the laboratory using different concentrations (0, 7.5, 15, 22.5, 30% of aqueous extracts from "falso-boldo" leaves harvested in all four seasons; extracts were obtained by grinding, maceration, infusion and decoction. Seeds were distributed on Petri dishes moistened with 10 mL solution. Results showed that the leaf extracts affected the germination of lettuce seeds only at the concentration of 30% extract prepared by decoction of leaves harvested in the winter. Germination speed index showed significant reduction for ground extracts prepared in the fall and winter, as well as for macerated leaves harvested in the summer and fall and for extracts prepared through decoction in the winter. The extracts stimulated the growth of shoots of lettuce seedlings, whereas root length was affected by the extracts, which either stimulated or inhibited its growth. Extracts of "falso-boldo" leaves harvested in all four seasons had allelopathic effect on germination and development of lettuce, and the latter varied depending on the harvest season, the form of preparing the extracts and the tested concentrations.

  13. Potenciação alelopática de extratos vegetais na germinação e no crescimento inicial de picão-preto e alface Allelopathy of plant extracts on germination and initial growth of beggartick (Bidens pilosa L. and lettuce (Lactuca sativa L.

    Directory of Open Access Journals (Sweden)

    Magda Cristiani Ferreira

    2007-08-01

    Full Text Available O picão-preto (Bidens pilosa L. é uma planta daninha muito agressiva, que está presente em quase todo Brasil. O principal método de controle é o químico, porém apresenta elevado impacto ambiental, risco de intoxicação humana e possibilidade de causar fitotoxicidade as culturas. O objetivo do trabalho foi avaliar o efeito alelopático de extratos etanólicos de Eucalyptus citriodora Hook. e Pinus elliottii L. na germinação e no crescimento inicial de picão-preto e alface (Lactuca sativa L.. Foram testadas quatro concentrações de cada extrato (0,25; 0,50; 1,0 e 2,0 % além do controle (0,0 % água destilada com Tween 20 a 0,08 %. O delineamento experimental foi o inteiramente casualizado, com quatro repetições em condições de laboratório. O extrato de P. elliottii não causou efeito alelopático sobre o picão-preto e o alface. O extrato de E. citriodora reduziu significativamente o índice de velocidade de germinação (IVG do picão-preto em todas as concentrações testadas quando comparadas com o controle (0,0%, porém para a alface o IVG foi significativo apenas na concentração de 2,0 %. Para o comprimento da raiz não foi possível observar diferença significativa entre os tratamentos para os dois extratos testados tanto para o alface como para o picão preto.Bidens pilosa L. is an aggressive weed found all over Brazil. The main control method for this species is chemical treatment however, causes strong environmental impact, and it has great human contamination risks, and may cause phytotoxity to crops. The objective of this study was to evaluate the effect of ethanolic extracts of Eucalyptus citriodora Hook. and Pinus elliottii L. on seed germination and initial growth of B. pilosa and lettuce (Lactuca sativa L.. Five concentrations of each extract (0.0; 0.25; 0.50; 1.0; 2.0% were tested in laboratory conditions using a randomized complete block design with four replicates. P. elliottii extract had no effect on B. pilosa and lettuce. However, E. citriodora extract, significantly reduced germination index (GI of B. pilosa, in all tested concentrations, when compared with the control composed by distilled water. Lettuce GI was affected only by 2,0% concentration of ethanolic extract. Extracts of both P. elliottii and E. citriodora had no significant effect on the root length parameter of both B. pilosa and lettuce.

  14. Phyto chemical study and evaluation of allelopathy in Memora peregrina, 'ciganinha', Bignoniaceae, an invading species in pastures in Mato Grosso do Sul, Brazil; Estudo fitoquimico e avaliacao alelopatica de Memora peregrina - 'ciganinha' - Bignoniaceae, uma especie invasora de pastagens em Mato Grosso do Sul

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, Rafaela Ferreira [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Quimica; Resende, Ubirazilda Maria [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Biologia; Silva, Walciane da; Macedo, Maria Ligia Rodrigues [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Ciencias Naturais; Butera, Ana Paola; Tulli, Elayne de Oliveira; Saffran, Francis Paes; Siqueira, Joao Maximo de [Mato Grosso do Sul Univ., Campo Grande, MS (Brazil). Dept. de Farmacia-Bioquamica]. E-mail: jmaximo@nin.ufms.br

    2005-04-01

    Memora peregrina (local name: 'ciganinha' - Bignoniaceae) is a weed that often invades pastures in the Brazilian state of Mato Grosso do Sul. From its leaves and subterranean parts, the following compounds were isolated: allantoin (20.7 w/w in subterranean parts), the iridoid 6{beta}-hydroxyipolamiide, hyperin, 3'-O-methylhyperin, 4-hydroxy-N-methylproline, {beta}-sitosterol, {alpha}-amirin and {beta}-amirin, and lupeol. Allantoin exhibited an activity of inducing germination in seeds of Lactuca sativa used as a biological model, and the iridoid showed moderate activity in the larval development of Anagasta kuehniella. These results, associated with this plant's behavior, are suggestive of the occurrence of adaptive and competitive strategies in relation to other plant species. (author)

  15. 草莓根系分泌物和腐解物中氨基酸的检测及其化感作用研究%Study on determination and allelopathy of amino acids in strawberry root exudates and decomposing products

    Institute of Scientific and Technical Information of China (English)

    甄文超; 王晓燕; 曹克强; 靳增军

    2004-01-01

    运用ACCQ.Tag法测定了草莓根系分泌物和腐解物中8种氨基酸的含量,并研究了不同氨基酸对草莓根病病原菌的化感作用.结果表明:根系分泌物和腐解物水提液中氨基酸含量高于醇提液,检测出的6种氨基酸中,丝氨酸、苏氨酸、脯氨酸和精氨酸对Fusarium oxysporum 和 Rhizoctonia solani的菌丝生长有明显的促进作用.苏氨酸、脯氨酸和精氨酸对F.oxysporum有明显促进作用,天冬氨酸和谷氨酸对3种病原菌菌丝生长均有明显的抑制作用;谷氨酸、天冬氨酸、丝氨酸、脯氨酸和精氨酸对Verticillium dahliae孢子萌发有明显促进作用,而苏氨酸对其孢子萌发有抑制作用.天冬氨酸和苏氨酸对F.oxysporwm的孢子萌发有明显抑制作用,谷氨酸对F.oxysporum孢子萌发无明显作用,其余3种能明显促进F.oxysporum孢子萌发.

  16. LC-MS based Metabolomics Analysis to Identify Potential Allelochemicals in Wedelia trilobata

    Directory of Open Access Journals (Sweden)

    Kamalrul Azlan Azizan

    2016-05-01

    Full Text Available Wedelia trilobata is a noxious invasive weed that has been widely cultivated as a decorative and groundcover plant. The plant has been reported to contain diverse bioactive compounds with a broad spectrum of biological activities including allelochemicals. Allelochemicals contribute to allelopathy interactions that suppress the growth and development of nearby plants. Several studies have reported the allelopathic potential of W. trilobata and its negative effects to crop plants. However, relatively little is known about the allelochemicals’ composition and how allelochemicals contribute to the allelopathic behavior of this plant. In order to prove allelopathy, the identification of the causative allelochemicals is required. The identification of potential allelochemicals that serve as biomarkers could be useful for assessing allelopathy interactions. In this study, a liquid chromatography (LC based metabolomics approach was applied to find biomarkers with allelopathic effects from W. trilobata. Ethanol and water were used to extract metabolites from the leaves of W. trilobata and analyzed using liquid chromatography coupled with quadrupole high-resolution time of flight mass spectrometry (LC-QTOF-MS. Using multivariate statistical analysis (MVA, we identified eight Rt-m/z pairs as candidate marker compounds for assessing allelopathy interactions of W. trilobata. The results highlight the application of metabolomics for understanding of the role of allelochemicals in allelopathy interactions of W. trilobata .

  17. Research Progress on Weed-controlling by Using Allelochemicals%利用化感物质防除杂草研究进展

    Institute of Scientific and Technical Information of China (English)

    赵强; 董晓宁; 井伟龙; 赵海福

    2012-01-01

    该文阐述了化感作用的作用机理,国内外植物化感抑草的研究现状,进而指出了植物化感作用在抑制杂草方面的优越性及存在的问题,同时对其未来的发展进行了展望.%By elaborating the mechanism of action of allelopathy and the research status of weed-controlling of allelopathy at home and abroad,further pointing out superiority and existing problems of allelopathy in the management of weeds,at the same time looking into the future.

  18. Ecological Effects of Allelopathic Plants

    DEFF Research Database (Denmark)

    Kruse, M.; Strandberg, M.; Strandberg, B.

    with the environment through spread of GM-plants or transgenes outside agricultural areas. The last chapter discuss GM-allelopathic plants in relation to the ecological risk assessment. Preface: This report is based on a literature review on allelopathy from an ecological impact point of view carried out in 1999...... on allelopathy in these crops. It discusses the ecological effects of allelopathic plants in natural ecosystems and factors of importance for the effects of these plants are pointed out. Finally the report presents suggestions for an ecological risk assessment of crops with an enhanced release of allelochemicals...

  19. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the mai

  20. Impact of kenaf (Hibiscus cannabinus L.) leaf, bark, and core extracts on germination of five plant species

    Science.gov (United States)

    The chemical interaction between plants, which is referred to as allelopathy, may result in the inhibition of plant growth and development. The objective of this research was to determine the impact of kenaf (Hibiscus cannabinus L.) plant extracts on the germination and post-germination development ...

  1. EPCOT, NASA and plant pathogens in space.

    Science.gov (United States)

    White, R

    1996-01-01

    Cooperative work between NASA and Walt Disney World's EPCOT Land Pavilion is described. Joint efforts include research about allelopathy in multi-species plant cropping in CELSS, LEDs as light sources in hydroponic systems, and the growth of plant pathogens in space.

  2. Is (-)-Catechin a "Novel Weapon" of Spotted Knapweed (Centaurea stoebe)?

    Science.gov (United States)

    The “novel weapons” hypothesis states that some invasive weed species owe part of their success as invaders to allelopathy mediated by allelochemicals that are new to the native species. Presumably, no resistance has evolved among the native species to this new allelochemical (i.e. the novel weapon...

  3. Methanol production from eucalyptus wood chips. Attachment VI. Florida's eucalyptus energy farm: the natural system interface

    Energy Technology Data Exchange (ETDEWEB)

    Fishkind, H.H.

    1982-05-01

    A review of pertinent literature covered the following: eucalypt background, the candidate species, biomass plantation considerations, effects of site production, leachate and allelopathy, and some exotic flora considerations. The comparative eucalypt field survey covers mined land stands, unmined south Florida stands, and Glade County eucalypt stands. The problem of eucalypt naturalization is discussed.

  4. Growth inhibition and colony formation in the cyanobacterium Microcystis aeruginosa induced by the cyanobacterium Cylindrospermopsis raciborskii

    NARCIS (Netherlands)

    Mello, M.M.; Soares, M.C.S.; Roland, F.; Lürling, M.F.L.L.W.

    2012-01-01

    In a tropical reservoir, the cyanobacteria Microcystis aeruginosa and Cylindrospermopsis raciborskii are the dominant species, with changes in dominance throughout the year. Since allelopathy has been suggested as a factor that could promote or stabilize harmful algal blooms, we investigated potenti

  5. 不同烤烟品种对莴苣的化感作用研究%Allelopathic Effect of Different Tobacco Varieties to Lettuce

    Institute of Scientific and Technical Information of China (English)

    耿锐梅; 罗成刚; 熊萍; 杨宏伟; 曹长代; 董世峰; 陈秀斋; 温亮; 李连玉

    2012-01-01

    The allelopathic potential of the root, stem and leaf of different flue-cured tobacco varieties were determined by sandwich method. The results showed that the allelopathy of different flue-cured tobacco had significant differences, its potential was leaf > stem > root, root length of lettuce > bud length, and allelopathy showed enhanced trend with the increase of consumption. The varieties ZhongyanlOO and K326 showed strong allelopathy, NCI02 and newly developed lines CF220 took the second place, and the NC89 and Yunyan87 showed weak allelopathy.%采用“三明治”生物测定方法,测定了不同烤烟品种根、茎和叶的化感潜力.结果表明,不同烤烟品种化感作用差异显著,化感作用强弱依次为叶>茎>根,对莴苣根长的化感作用强于芽长,且随着用量的增加化感作用呈现增强趋势;其中,中烟100和K326的化感作用较强,NC102和新育成推广品种(系)CF220次之,NC89和云烟87较弱.

  6. Chemical warfare in freshwater

    NARCIS (Netherlands)

    Mulderij, Gabi

    2006-01-01

    Aquatic macrophytes can excrete chemical substances into their enviroment and these compounds may inhibit the growth of phytoplankton. This process is defined as allelopathy: one organism has effects on another via the excretion of a (mixture of) chemical substance(s). With laboratory and field expe

  7. Searching for allelopathic effects of submerged macrophytes on phytoplankton-state of the art and open questions

    NARCIS (Netherlands)

    Gross, E.M.; Hilt (nee Körner), S.; Lombardo, P.; Mulderij, G.

    2007-01-01

    Allelopathy, here defined as biochemical interactions between aquatic primary producers, has always been intriguing as a process explaining the dominance of certain plant or algal species over others. Negative chemical interference has been invoked as one of the steering mechanisms behind mutual dom

  8. Kenaf (Hibiscus cannabinus L.) impact on post-germination seedling growth

    Science.gov (United States)

    The chemical interaction between plants, which is referred to as allelopathy, may result in the inhibition of plant growth and development. The objective of this research was to determine the impact of kenaf (Hibiscus cannabinus L.) plant extracts on the post-germination growth of five plant species...

  9. Physiological conjunction of allelochemicals and desert plants.

    Directory of Open Access Journals (Sweden)

    Avital Yosef Friedjung

    Full Text Available Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  10. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae

    OpenAIRE

    Shearer, TL; Rasher, DB; Snell, TW; Hay, ME

    2012-01-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survi...

  11. Emerging Insights on Brazilian Pepper Tree (Schinus terebinthifolius) Invasion: The Potential Role of Soil Microorganisms

    OpenAIRE

    Dawkins, Karim; Esiobu, Nwadiuto

    2016-01-01

    Invasive plant species constitute a major ecological and economic problem worldwide, often distorting trophic levels and ecosystem balance. Numerous studies implicate factors ranging from environmental plasticity, competition for nutrient and space, and allelopathy in the success of invasive species in general. The Brazilian Pepper tree (BP) was introduced to the United States in the 1800s and has since become a category one invasive plant in Florida. It has aggressively spread to about 3000 ...

  12. Emerging insights on Brazilian Pepper tree (Schinus terebinthifolius) invasion : the potential role of soil microorganisms

    OpenAIRE

    Karim eDawkins; Nwadiuto eEsiobu

    2016-01-01

    Invasive plant species constitute a major ecological and economic problem worldwide, often distorting trophic levels and ecosystem balance. Numerous studies implicate factors ranging from environmental plasticity, competition for nutrient and space, and allelopathy in the success of invasive species in general. The Brazilian Pepper tree (BP) was introduced to the United States in the 1800s and has since become a category one invasive plant in Florida. It has aggressively spread to about 3000 ...

  13. Harmful and beneficial aspects of Parthenium hysterophorus: an update

    OpenAIRE

    Patel, Seema

    2011-01-01

    Parthenium hysterophorus is a noxious weed in America, Asia, Africa and Australia. This weed is considered to be a cause of allergic respiratory problems, contact dermatitis, mutagenicity in human and livestock. Crop production is drastically reduced owing to its allelopathy. Also aggressive dominance of this weed threatens biodiversity. Eradication of P. hysterophorus by burning, chemical herbicides, eucalyptus oil and biological control by leaf-feeding beetle, stem-galling moth, stem-boring...

  14. Identification and Phytotoxicity Assessment of Phenolic Compounds in Chrysanthemoides monilifera subsp. monilifera (Boneseed.

    Directory of Open Access Journals (Sweden)

    Md Abdullah Yousuf Al Harun

    Full Text Available Chrysanthemoides monilifera subsp. monilifera (boneseed, a weed of national significance in Australia, threatens indigenous species and crop production through allelopathy. We aimed to identify phenolic compounds produced by boneseed and to assess their phytotoxicity on native species. Phenolic compounds in water and methanol extracts, and in decomposed litter-mediated soil leachate were identified using HPLC, and phytotoxicity of identified phenolics was assessed (repeatedly through a standard germination bioassay on native Isotoma axillaris. The impact of boneseed litter on native Xerochrysum bracteatum was evaluated using field soil in a greenhouse. Collectively, we found the highest quantity of phenolic compounds in boneseed litter followed by leaf, root and stem. Quantity varied with extraction media. The rank of phenolics concentration in boneseed was in the order of ferulic acid > phloridzin > catechin > p-coumaric acid and they inhibited germination of I. axillaris with the rank of ferulic acid > catechin > phloridzin > p-coumaric acid. Synergistic effects were more severe compared to individual phenolics. The litter-mediated soil leachate (collected after15 days exhibited strong phytotoxicity to I. axillaris despite the level of phenolic compounds in the decomposed leachate being decreased significantly compared with their initial level. This suggests the presence of other unidentified allelochemicals that individually or synergistically contributed to the phytotoxicity. Further, the dose response phytotoxic impacts exhibited by the boneseed litter-mediated soil to native X. bracteatum in a more naturalistic greenhouse experiment might ensure the potential allelopathy of other chemical compounds in the boneseed invasion. The reduction of leaf relative water content and chlorophyll level in X. bracteatum suggest possible mechanisms underpinning plant growth inhibition caused by boneseed litter allelopathy. The presence of a substantial

  15. Influence of barley straw and submerged macrophytes on fishpond wastewater quality

    OpenAIRE

    Ghobrial, M.G.; Okbah, M.A.; Gharib, S.M.; A. M. Soliman

    2007-01-01

    Barley straw has received, recently, considerable attention as an algicide, which could be used to control algal growth in fishponds. It is regarded as cost-effective, user friendly and environmentally sounds. On the other hand, the submerged wetland macrophytes are crucial for the stabilization of clear water state in shallow lakes, by their active production of anti-algal compounds (allelochemicals) through allelopathy. Microcosm experiments using barley straw and the submerged macrophytes:...

  16. Allelopathy—A Tool to Improve the Weed Competitive Ability of Wheat with Herbicide-Resistant Black-Grass (Alopecurus myosuroides Huds.)

    OpenAIRE

    Nils-Ove Bertholdsson

    2012-01-01

    Controlling black-grass in winter wheat production in northern Europe is an increasing problem because of more frequent winter crops and development of herbicide resistance in weeds. Alternative weed management strategies are needed, e.g., use of more competitive cultivars. Factors that increase cultivar competitiveness include early vigor and straw length, but also allelopathy. Therefore, the allelopathic properties of wheat cultivars included in the Swedish national list or in the release p...

  17. EFFECT OF Medicago varia Martin.cv.CaoYuan No.3 ON GERMINATION AND GROWTH OF THREE KINDS OF RECEPTOR PLANTSp%草原3号杂花苜蓿不同发芽方式对几种牧草萌发生长的影响

    Institute of Scientific and Technical Information of China (English)

    包赛很那; 海棠

    2011-01-01

    Study allelopathy of receiver plant Bromus ciliatus L. , Psathyrostachys juncea and Agropyron mongolicum Keng with Medi-cago varia Martin, cv. CaoYuanNo. 3. In direct seeding and germination conditions. The results show that, Medicago varia Martin, cv. CaoYuan No. 3 the existence of three kinds of forage allelopathy in different conditions. The order of allelopathy of 3 pasture is that Psathyrostachys juncea > Bromus ciliatus L. > Agropyron mongolicum Keng in a living condition, The order of allelopathy of 3 pasture is that Bromus ciliatus L. > Psathyrostachys juncea > Agropyron mongolicum Keng in a germination condition. Prairie 3 Varia have some differences in Germination and growth period after emergence of three allelopathic effects of pasture..%用草原3号杂花苜蓿(Medicago varia Martin.cv.CaoYuanNo.3)在直播和催芽条件下对受体牧草缘毛雀麦(Bromus ciliatus L.)、新麦草(Psathyrostachys juncea)、蒙古冰草(Agropyron mongolicum Keng.)的化感效应进行研究,结果表明,草原3号杂花苜蓿不同发芽条件下对3种牧草存在化感效应.直播条件下对3种牧草的化感效应大小顺序为新麦草>缘毛雀麦>蒙古冰草,催芽条件下对3种牧草的化感效应大小顺序为缘毛雀麦>新麦草>蒙古冰草;草原3号杂花苜蓿发芽期和发芽后生长期对3种牧草的化感效应有一定差异.

  18. LC-MS based Metabolomics Analysis to Identify Potential Allelochemicals in Wedelia trilobata

    OpenAIRE

    Kamalrul Azlan Azizan; Sarah Ibrahim; Nurul Haizun Abdul Ghani; Mohammad Firdaus Nawawi

    2016-01-01

    Wedelia trilobata is a noxious invasive weed that has been widely cultivated as a decorative and groundcover plant. The plant has been reported to contain diverse bioactive compounds with a broad spectrum of biological activities including allelochemicals. Allelochemicals contribute to allelopathy interactions that suppress the growth and development of nearby plants. Several studies have reported the allelopathic potential of W. trilobata and its negative effects to crop plants. However, rel...

  19. [Plant hydroponics and its application prospect in medicinal plants study].

    Science.gov (United States)

    Zeng, Yan; Guo, Lan-Ping; Huang, Lu-Qi; Sun, Yu-Zhang

    2007-03-01

    This article introduced the theorem and method of hydroponics. Some examples of studies in agriculture and forestry were presented, the effects of elements, environmental stress and hormones on physiology of medicinal plants by using hydroponics were analyzed. It also introduced the feasibility and advantage of hydroponics in intermediate propagation and allelopathy of medicinal plant. And finally it made the conclusion that the way of hydroponics would be widely used in medicinal plant study.

  20. Effects of Eichhornia crassipes Growth on Aquatic Plants in Dianchi Lake

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianch...

  1. 植物间化感作用机理研究进展%Advances in Research on the Allelopathic of Plants

    Institute of Scientific and Technical Information of China (English)

    成钢; 张丹; 王伟亮; 朱伟玲; 琚淑明

    2015-01-01

    为了系统认识化感物质对植物作用的机理,从植物生长发育、生理生化代谢、基因表达3个方面对国内外植物化感作用的研究成果进行了综述。%Allelopathy can be widely found in the species.It is the main way of plants affect other plants and themselves.Also it is the important research direction to study the relationship between species.It help us learn more about the composition of the commu-nity and the process of succession.As the media of allelopathy ,allelochemical can play a role in itself and other plants.In order to understand the system of plant allelochemicals on the mechanism of action of plant rational allocation ,the correct choice of mixed species to create a healthy plant community systems provide a theoretical basis ,this article from allelochemicals on plant mineral ele-ment absorption , morphology ,physiology and biochemistry ,gene expression four on domestic and international aspects of plant allel-opathy studies were reviewed.

  2. Allelopathic interactions between the brown algal genus Lobophora (Dictyotales, Phaeophyceae) and scleractinian corals.

    Science.gov (United States)

    Vieira, Christophe; Thomas, Olivier P; Culioli, Gérald; Genta-Jouve, Grégory; Houlbreque, Fanny; Gaubert, Julie; De Clerck, Olivier; Payri, Claude E

    2016-01-01

    Allelopathy has been recently suggested as a mechanism by which macroalgae may outcompete corals in damaged reefs. Members of the brown algal genus Lobophora are commonly observed in close contact with scleractinian corals and have been considered responsible for negative effects of macroalgae to scleractinian corals. Recent field assays have suggested the potential role of chemical mediators in this interaction. We performed in situ bioassays testing the allelopathy of crude extracts and isolated compounds of several Lobophora species, naturally associated or not with corals, against four corals in New Caledonia. Our results showed that, regardless of their natural association with corals, organic extracts from species of the genus Lobophora are intrinsically capable of bleaching some coral species upon direct contact. Additionally, three new C21 polyunsaturated alcohols named lobophorenols A-C (1-3) were isolated and identified. Significant allelopathic effects against Acropora muricata were identified for these compounds. In situ observations in New Caledonia, however, indicated that while allelopathic interactions are likely to occur at the macroalgal-coral interface, Lobophora spp. rarely bleached their coral hosts. These findings are important toward our understanding of the importance of allelopathy versus other processes such as herbivory in the interaction between macroalgae and corals in reef ecosystems. PMID:26728003

  3. Mechanism and Active Variety of Allelochemicals%植物化感物质活性变化及其作用机理研究进展

    Institute of Scientific and Technical Information of China (English)

    彭少麟; 文军; 郭勤峰

    2004-01-01

    本文综述了化感物质活性的变化、变化的原因及其功能机理.化感物质活性在自然过程中,由于温度、光周期、水和土壤等的不同而变化,在功能过程中随其初始浓度、化合物结构和混合程度不同而变化,在植物体内由于组织器官和成熟程度不同而变化,而研究技术和操作过程也影响化感物质的活性.文章还讨论了未来化感作用研究的发展方向.未来化感作用研究将集焦于如下五方面:(1)更有效地在实践中,特别是在农业生产过程中鉴定和提纯化感物质;(2)化感作用在分子结构水平的功能定位;(3)应用化感作用解释植物种间相互作用;(4)化感作用在植被演替过程中的驱动力作用;(5)化感作用在进化过程中的意义.%This article summarizes allelochemicals' active variety, its potential causes and function mechanisms. Allelochemicals' activity varies with temperature, photoperiod, water and soils during natural processes, with its initial concentration, compound structure and mixed degree during functional processes,with plant accessions, tissues and maturity within-species, and with research techniques and operation processes. The prospective developmental aspects of allelopathy studies in the future are discussed.Future research should focus on: (1) to identify and purify allelochemicals more effectively, especially for agriculture, (2) the functions of allelopathy at the molecular structure level, (3) using allelopathy to explain plant species interactions, (4) allelopathy as a driving force of succession, and (5) the significance of allelopathy in the evolutionary processes.

  4. Weed-Suppressing Effect and Mechanism of Allelopathic Rice Accessions

    Institute of Scientific and Technical Information of China (English)

    HUFei; KONGChui-hua; XUXiao-hua; ZHANGChao-xian; CHENXiong-hui

    2004-01-01

    Two allelopathic rice accessions, PI312777 and Allelopathy i, significantly suppressed the growth of associated weeds in the field. Moreover, their weed-suppressing effects were correlated with the cultivation patterns. The weed-suppressing effects of throwing and transplanting were more effective than that of direct seeding. Furthermore, the amounts of allelochemicals (resorcinols, flavones and hydroxamic acids) produced and released from two allelopathic rice accessions were much higher than that from a nonallelopathic rice variety Hua-Jing-Xian i, and reached the maximum concentration at the 6th leaf stage. Differences in the weed-suppressing effects of rice accessions appear to result from the accessions producing and releasing different amounts of allelochemicals in the field. Further research confirmed that in PI312777 plants, allelochemicals were synthesized by the above-ground parts, and then secreted through the root tissues. Root tissues of PI312777 plants never produced the allelochemicals. Root exudates from PI312777 could significantly inhibit the growth of E. crus-galli surrounding rice plants in water culture. However, when activated carbon was added to the culture solution, which could absorb allelochemicals from root exudates, the growth of E. crus-galli was no longer significantly inhibited. Weed-suppressing effects of rice accessions depended on allelopathy, cultivation patterns and other factors in rice fields, while allelopathy was one of important factors. Interestingly, the amounts of allelochemicals produced and released from allelopathic rice plants may be induced by the presence of E. crus-galli.This suggests that there is a possible chemical recognition between rice and E. crus-galli.

  5. Chemical ecology of marine plankton.

    Science.gov (United States)

    Schwartz, Emily R; Poulin, Remington X; Mojib, Nazia; Kubanek, Julia

    2016-07-28

    Covering: January 2013 to online publication December 2014This review summarizes recent research in the chemical ecology of marine pelagic ecosystems, and aims to provide a comprehensive overview of advances in the field in the time period covered. In order to highlight the role of chemical cues and toxins in plankton ecology this review has been organized by ecological interaction types starting with intraspecific interactions, then interspecific interactions (including facilitation and mutualism, host-parasite, allelopathy, and predator-prey), and finally community and ecosystem-wide interactions. PMID:27090772

  6. Review of plant metabolism and secondary metabolites function%植物次生代谢作用及其产物概述

    Institute of Scientific and Technical Information of China (English)

    刘立新; 梁鸣早

    2009-01-01

    @@ 1937年,德国科学家H.Molish提出植物相生相克的化感作用(Allelopathy)的概念之后,引起全球科学家的关注,其中植物生理学、植物生物化学、化学生态学、植物保护学等领域的科学家从不同角度对其进行研究,得出大致相似但又各有侧重的结论[1-15].

  7. Allelopathic effects of extracts from Solidago canadensis L.against seed germination and seedling growth of some plants

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous and ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepared and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry (Morus alba); morning glory (Pharbitis nil), wheat (Triticum aestivum) and rape (Brassica campestris). Reduction and/or growth in germination and growth of the target plant species in the presence of both aqueous and ethanolic extracts at different concentrations indicated that the responses were species-specific and concentration-dependent. Generally, ethanolic extracts (especially from leaves) imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.001 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulberry. It is suggested that the aqueous and ethanolic extracts of all the three parts ofS. canadensis have significant allelopathic effects. Although both inhibition and stimulation occurred in the germination and growth of the target species, extracts with higher concentrations definitely inhibit seed germination and seedling growth of all target plants. We suggest that allelopathy plays a more important role than other mechanisms do in the out-competition of S. canadensis over other plants, and make it invasive in new habitats.

  8. Evidence for an allelopathic interaction between rye and wild oats.

    Science.gov (United States)

    Macías, Francisco A; Oliveros-Bastidas, Alberto; Marín, David; Chinchilla, Nuria; Castellano, Diego; Molinillo, José M G

    2014-10-01

    Allelopathy is a biological phenomenon in which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. Allelopathy has been the subject of a great deal of research in chemical ecology since the 1930s. The characterization of the factors that influence this phenomenon has barely been explored, mainly due to the complexity of this area. The main aim of the research carried out to date has been to shed light on the importance of these interactions in agroecosystems, especially in relation to the interactions between crops and weeds. Herein we report the characterization of a complete allelochemical pathway involving benzoxazinones, which are known to participate in allelopathic plant defense interactions of several plants of high agronomic interest. The production of the defense chemicals by a donor plant (crop), the route and transformations of the chemicals released into the environment, and the uptake and phytotoxic effects on a target plant (weed) were all monitored. The results of this study, which is the first of its kind, allowed a complete dynamic characterization of the allelopathic phenomenon for benzoxazinones.

  9. Research on the Alleloiathy of Tithonia diversifolia on the Phaseolus radiate and Orvza sativa Seed%肿柄菊对绿豆和水稻种子的化感作用

    Institute of Scientific and Technical Information of China (English)

    杨海艳; 罗中泽; 李桂花; 徐成东

    2011-01-01

    [目的]研究不同浓度的肿柄菊叶、茎和花序水浸提液对绿豆和水稻种子萌发的化感作用.[方法]分别用蒸馏水对肿柄菊叶、茎和花序进行活性物质浸提,并稀释为3.0%、1.O%和0.5%3个浓度,采用培养皿滤纸法进行种子萌发和幼苗生长试验,研究不同浓度不同部位肿柄菊对绿豆和水稻种子萌发的化感作用.[结果]肿柄菊叶、茎、花序水浸提液均对绿豆和水稻种子萌发和幼苗生长产生一定的抑制作用,并且随着肿柄菊不同部位的水浸提液浓度的增加,其化感效应不断增强;肿柄菊不同部位水浸提液在相同浓度下对绿豆和水稻种子的化感效应强度顺序大体呈现为:叶>花序>茎.[结论]肿柄菊植株不同部位及浓度的水浸提液均对绿豆和水稻种子产生化感效应,这也可能是肿柄菊入侵的重要机制.%[ Objective ] The allelopathy of the different concentrations of the extracts from Tithonia diversifolia leaf, stem and inflorescence on the germination of Phaseolus radiate and Oryza sativa was studied. [ Method] The active material in the Tithonia diversifolia leaf, stem and capitula were extracted with distilled water, then were diluted to the concentration of 3.0 %, 1.0 % and 0.5% and finally the experiment in the seed germination rate and seedling growth of Phaseolus radiate and Oryza sativa under the treatment of those concentrations was conducted in order to research the allelopathy of the different treatments to them. [ Result] The results showed that the aqueous extracts from leaf, stem and inflorescence of Tithonia diversifolia had considerable inhibitory effect on seed germination rate and seedling growth of Phaseolus radiate and Oryza sativa and the allelopathy was gradually was intensified with the concentration-increasing of those active materials. The order of the allelopathy intensity of the active material from different parts at same concentration was leaf > capitula

  10. Effects of Chinese onion's root exudates on cucumber seedlings growth and rhizosphere soil microorganisms%分蘖洋葱根系分泌物对黄瓜幼苗生长及根际土壤微生物的影响

    Institute of Scientific and Technical Information of China (English)

    杨阳; 刘守伟; 潘凯; 吴凤芝

    2013-01-01

    以不同化感潜力分蘖洋葱为供体,黄瓜为受体,研究了分蘖洋葱根系分泌物对黄瓜幼苗生长、根际土壤微生物数量及细菌群落结构的影响.结果表明:不同化感潜力分蘖洋葱根系分泌物对黄瓜幼苗生长均具有促进作用,且随着浓度的升高,促进作用增强,相同浓度下,化感潜力强、弱供体之间差异不显著;不同化感潜力分蘖洋葱根系分泌物均增加了黄瓜根际土壤细菌和放线菌数量,降低了真菌和尖镰孢菌数量,化感潜力强的品种(L-06)效果更显著;不同化感潜力分蘖洋葱根系分泌物均能提高黄瓜根际土壤细菌群落丰富度,差异条带的序列片段经比对推测为3大细菌类群:Actinobacteria(放线菌纲)、Proteobacteria(变形菌纲)和Anaerolineaceae(厌氧绳菌纲),其中厌氧绳菌只出现在化感潜力强(L-06)的处理中.化感潜力强(L-06)、浓度高(10 mL·株-1)的分蘖洋葱根系分泌物更有利于黄瓜根际土壤细菌群落丰富度的提高.%Taking the Chinese onion cultivars with different allelopathy potentials as the donor and cucumber as the accepter, this paper studied the effects of Chinese onion' s root exudates on the seedlings growth of cucumber and the culturable microbial number and bacterial community structure in the seedlings rhizosphere soil. The root exudates of the Chinese onion cultivars could promote the growth of cucumber seedlings, and the stimulatory effect increased with the increasing concentration of the root exudates. However, at the same concentrations of root exudates, the stimulatory effect had no significant differences between the Chinese onion cultivars with strong and weak allelopathy potential. The root exudates of the Chinese onion cultivars increased the individual numbers of bacteria and actinomyces but decreased those of fungi and Fusarium in rhizosphere soil, being more significant for the Chinese onion cultivar with high allelopathy potential (L-06

  11. 新千年的挑战:第三届世界植物化感作用大会综述

    Institute of Scientific and Technical Information of China (English)

    孔垂华

    2003-01-01

    @@ 1 引言 近30年来,化学生态学已逐步建立了独立的学科体系,并愈来愈受到重视和不断取得进展.1975年国际化学生态学会(International Society of Chemical Ecology, ISCE)成立,并正式出版会刊Journal of Chemical Ecology.国际化学生态学会关注的4个主要研究领域是:1)种内信息素(pheromone); 2)化学通讯(chemical communication);3)种间化学传导和化感物质 (Allelochemical);4)植物化感作用 (Allelopathy).因此,植物化感作用一直是化学生态学研究的主重要内容之一.1994年,世界从事植物化感作用研究的科学家成立了独立的国际植物化感作用学会(International Allelopathy Society, IAS), 出版会刊Allelopathy Journal, 并决定每三年在各大洲举行一次世界植物化感作用大会.1996年在欧洲西班牙召开了第一次大会,1999年在北美洲加拿大召开了第二次大会,第三届世界植物化感作用大会于2002年8月26~30日在亚洲日本科学城筑波举行,作者在国家自然科学基金和第三次世界植物化感作用大会组委会的资助下,应邀出席了大会.现将会议情况作一综述,并就国际植物化感作用研究中的问题和对策表明作者的看法和认识.

  12. Plants Release Precursors of Histone Deacetylase Inhibitors to Suppress Growth of Competitors.

    Science.gov (United States)

    Venturelli, Sascha; Belz, Regina G; Kämper, Andreas; Berger, Alexander; von Horn, Kyra; Wegner, André; Böcker, Alexander; Zabulon, Gérald; Langenecker, Tobias; Kohlbacher, Oliver; Barneche, Fredy; Weigel, Detlef; Lauer, Ulrich M; Bitzer, Michael; Becker, Claude

    2015-11-01

    To secure their access to water, light, and nutrients, many plant species have developed allelopathic strategies to suppress competitors. To this end, they release into the rhizosphere phytotoxic substances that inhibit the germination and growth of neighbors. Despite the importance of allelopathy in shaping natural plant communities and for agricultural production, the underlying molecular mechanisms are largely unknown. Here, we report that allelochemicals derived from the common class of cyclic hydroxamic acid root exudates directly affect the chromatin-modifying machinery in Arabidopsis thaliana. These allelochemicals inhibit histone deacetylases both in vitro and in vivo and exert their activity through locus-specific alterations of histone acetylation and associated gene expression. Our multilevel analysis collectively shows how plant-plant interactions interfere with a fundamental cellular process, histone acetylation, by targeting an evolutionarily highly conserved class of enzymes.

  13. The influence of extracellular compounds produced by selected Baltic cyanobacteria, diatoms and dinoflagellates on growth of green algae Chlorella vulgaris

    Science.gov (United States)

    Żak, Adam; Kosakowska, Alicja

    2015-12-01

    Secondary metabolites produced by bacteria, fungi, algae and plants could affect the growth and development of biological and agricultural systems. This natural process that occurs worldwide is known as allelopathy. The main goal of this work was to investigate the influence of metabolites obtained from phytoplankton monocultures on the growth of green algae Chlorella vulgaris. We selected 6 species occurring in the Baltic Sea from 3 different taxonomic groups: cyanobacteria (Aphanizomenon flos-aquae; Planktothrix agardhii), diatoms (Thalassiosira pseudonana; Chaetoceros wighamii) and dinoflagellates (Alexandrium ostenfeldii; Prorocentrum minimum). In this study we have demonstrated that some of selected organisms caused allelopathic effects against microalgae. Both the negative and positive effects of collected cell-free filtrates on C. vulgaris growth, chlorophyll a concentration and fluorescence parameters (OJIP, QY, NPQ) have been observed. No evidence has been found for the impact on morphology and viability of C. vulgaris cells.

  14. The Response of Arabidopsis to Co-cultivation with Clover

    DEFF Research Database (Denmark)

    Pedersen, Hans; Kudsk, Per; Fiehn, Oliver;

    2013-01-01

    Allelopathy contributes to interspecific interference in plants beyond competition for nutrients and sunlight and is of interest in agriculture due to its potential use in weed suppression. In order to study allelopathic effects in a model system, Arabidopsis thaliana and Trifolium repens were co-cultivated...... on nutrient medium in sterile containers for two weeks and then harvested, extracted and analyzed by GC-TOF-MS. 163 metabolites were identified using the automated database BinBase. Comparing metabolite peak areas in co-cultivated and control seedlings revealed an altered metabolic profile for both species...... in terms of several metabolite groups including amino acids, phenolics, carbohydrates and lipids. 87 A. thaliana and 53 T. repens metabolites were significantly affected. In A. thaliana 34 metabolites increased relative to the control upon co-cultivation while 54 decreased; in T. repens 20 increased while...

  15. 化感物质的提取、分离及鉴定方法的研究

    Institute of Scientific and Technical Information of China (English)

    陈绍莉; 周宝利

    2010-01-01

    @@ 化感作用属于化学生态学的研究范畴,是一门新兴学科.化感作用的英文为"Allelopathy",源于希腊语"Allelon(相互)"和"Pathos(损害、妨碍)".1937年Molish首先将其定义为:某种植物(包括微生物)生成的化学物质对其他植物产生某种作用的现象.随着科学研究的迅速发展,对化感作用的认识也在不断深入和全面.

  16. Allelochemicals Identification in the Root and the Rhizosperic Soil of Parsley%西芹鲜根及根际区物化感物质成分鉴定

    Institute of Scientific and Technical Information of China (English)

    陈磊; 云兴福

    2012-01-01

    In order to investigate the allelochemicals in the root and the rhizosperic soil of parsley,the column chromatography and GC-MS were used to study the best allelopathy fraction of different extracts in the root and the rhizosperic soil of parsley after secondary separation. The results showed the main allelochemicals of the best allelopathy fraction of the ethanol extract in the root and the rhizosperic soil of parsley after secondary separation were 4-Dimethylamino-2-methyl-l-phenyl-butan-2-ol,8-Octadecenoic acid, methyl ester, Hexadecanoic acid, methyl ester, Octadecadienoic acid,methyl ester;the main allelochemicals of the best allelopathy fraction of the acetone extract in the root and the rhizosperic soil of parsley after secondary separation were 2-Propenoic acid, pentadecyl ester; the main allelochemicals of the best allelopathy fraction of the aqueous extract in the root and the rhizosperic soil of parsley after secondary separation were 1-Hexadecanamine, N,N-dimethyl-,Pentadecanoic acid, 14-methyl-,methyl ester,Cyclotrisiloxane, hexamethyl-, 9-Octadecenoic acid, methyl ester, ( E)-, Methyl ricinoleate, Heptadecanoic acid, 16-methyl-, methyl ester.%为探讨西芹鲜根及根际区物化感物质成分,利用柱层析法及GC-MS对西芹鲜根及根际区物不同浸提液二次层析后化感效应最佳流分进行分离鉴定.结果表明,西芹鲜根与根际区物乙醇浸提液二次层析后化感效应最佳流分的主要化感成分均为4-二甲氨基-2-甲基-1-苯基-丁-2-醇、8-十八烯酸甲酯、棕榈酸甲酯、十八烷二烯酸甲酯;西芹鲜根与根际区物丙酮浸提液二次层析后化感效应最佳流分的主要化感成分为2-丙烯酸十五烷基酯;西芹鲜根与根际区物水浸提液二次层析后化感效应最佳流分的主要化感成分为十六烷基二甲基叔胺、14-甲基十五烷酸甲酯、六甲基环三硅氧烷、(E)-9-十八烯酸甲酯、蓖麻油酸甲酯、16-甲基十七烷酸甲酯.

  17. A solid phase extraction based non-disruptive sampling technique to investigate the surface chemistry of macroalgae.

    Science.gov (United States)

    Cirri, Emilio; Grosser, Katharina; Pohnert, Georg

    2016-01-01

    The surface chemistry of aquatic organisms determines their biotic interactions. Metabolites in the spatially limited laminar boundary layer mediate processes, such as antifouling, allelopathy and chemical defense against herbivores. However, very few methods are available for the investigation of such surface metabolites. An approach is described in which surfaces are extracted by means of C18 solid phase material. By powdering wet algal surfaces with this material, organic compounds are adsorbed and can be easily recovered for subsequent liquid chromatography/mass spectrometry (LC/MS) and gas chromatography/mass spectrometry (GC/MS) investigations. The method is robust, picks up metabolites of a broad polarity range and is easy to handle. It is more universal compared to established solvent dipping protocols and it does not cause damage to the test organisms. A protocol is introduced for the macroalgae Fucus vesiculosus, Caulerpa taxifolia and Gracilaria vermiculophylla, but it can be easily transferred to other aquatic organisms. PMID:26795737

  18. 不同生境中桂花叶的化感潜力研究%Compare the Allelopathic Potential of Osmanthus fragrans in Different Habitats

    Institute of Scientific and Technical Information of China (English)

    李富荣; 何桂银; 周巧劲; 阿锡英; 梁士楚

    2013-01-01

    To compare the allelopathy of Osmanthus fragrans in four different habitats,the allelopathic potential of aqueous extracts of the fresh and fallen leaves of O. fragrans to radish was studied by using indoor Petri dish bioassay method. The results showed that aqueous extracts from both the fresh and fallen leaves in the four habitats all had allelopathic effects. However,the differences of allelopathic potential existed under different situations. In the same habitat, the allelopathy inhibition of fresh leaves was usually stronger than that of fallen leaves,which may be relative to the contents and kinds of different allelochemicals. Except the fallen leaves in Qixing Park and Guilin Landscape Botanical Garden,the aqueous extracts of the other leaves significantly inhibited the seed germination of radish. In more cases, the allelopathy inhibition of the aqueous extracts of O. fragrans leaves on root growth was stronger than that on the stem length of radish seedlings. The allelopathy inhibition was beneficial to improve O. fragrans grow better in the competition with other plants. This study provided some theory basis to guide the widely cultivation and rationally arrangement of O. fragrans.%以萝卜种子为受体,采用培养皿法比较研究4种生境中桂花新鲜叶和凋落叶的化感潜力.结果表明:各生境中桂花叶片都具有一定的化感潜力,但不同情况下其化感效应有所差别.同一生境中,桂花新鲜叶比凋落叶浸提液的化感抑制作用要强,这可能与其化感物质的含量或种类有关.从植物浸提液对萝卜种子萌发率影响的结果来看,除七星公园和园林植物园桂花凋落叶对种子萌发抑制作用不明显外,其他情况下的浸提液都出现了明显的抑制效应.另外,除园林植物园桂花叶片浸提液以外,其他情况下的桂花叶片对萝卜根长的抑制效应都比对苗高的要强.桂花的化感抑制效应对其在与其他植物的竞争中获得更多资

  19. Bioactivity effect of two macrophyte extracts on growth performance of two bloom-forming cyanophytes

    Directory of Open Access Journals (Sweden)

    M.G. Ghobrial

    2015-01-01

    Full Text Available Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial (positive allelopathy or detrimental (negative allelopathy effects on the target organisms. The current research aims at using selected brackish water adapted submerged aquatic macrophytes allelopathy to combat bloom-forming cyanophytes, in laboratory bioassay experiments. Dry matters of macrophytes were extracted in solvents and the initial cyanophytes inoculum, derived from unialgal culture media, was used. Therefore, aqueous extracts with 50% and 100% acetone and ethanol solvents of two freshwater macrophytes; Potamogeton pectinatus and Ceratophyllum demersum were used to test their growth performance exhibited on two bloom-forming cyanophytes, Microcystis aeruginosa and Oscillatoria tenuis. The results revealed insignificant difference between the overall total average growth performance at treatment with 50% and 100% Ceratophyllum acetone extracts expressed by optical density (OD as well as chlorophyll a (chl a. Results showed, also, stimulation of M. aeruginosa growth. The highest growth increase in 100 μl/100 ml treatment with 50% acetone extract had a percentage rate (R of 94.66. On the contrary, treatment with ethanol extract recorded the highest inhibitory effect, thus in 1.5 μl/100 ml treatment with 50% Ceratophyllum ethanol extract R recorded −87.54, sustaining LC50 value of 1.12 μl/100 ml. The highest stimulating effect in 105 μl/100 ml treatment with 50% Ceratophyllum acetone extracts against O. tenuis was; R, 169.4. The highest inhibition in 1500 μl/100 ml treatment with 50% Ceratophyllum ethanol extracts against O. tenuis was; R −74.32, with LC50 0.830 μl/100 ml. While, the highest inhibition by 50% and 100% Potamogeton acetone or ethanol extracts against M. aeruginosa was

  20. Study of Allelopathic Interaction of Wheat (Triticum Aestivum L. and Rye (Secale Cereal L. Using Equal-Compartment-Agar Method

    Directory of Open Access Journals (Sweden)

    M. Fariba

    2009-10-01

    Full Text Available There are many methods for weed management one of them is using allelopathy in weedmanagement programs. Equal-compartment-agar method was used for studying allelopathic interaction ofwheat and rye. In order to studying of sowing time (delayed sowing, synchronic sowing on allelopathicinteraction of wheat cultivars (Shiraz, Roshan, Tabasi, Niknejad and rye (Secale cereale on primary growthof rye and wheat, an experiment was done as factorial arrangement in a completely randomized design with4 replications. According to the results, the inhibitory effect of w heat on rye was more than in synchronicsowing, compared to delayed sowing. Roshan had the highest allelopathic potential on rye, compared to otherwheat cultivars. On the other hands, Roshan cultivar showed the highest sensitivity in the presence of rye. Rootlength showed the most sensitivity to released allelochemicals from wheat cultivars, because root has the mostcontact with allelochemicals.

  1. Potential of Root Exudates from Wetland Plants and Their Potential Role for Denitrification and Allelopathic Interactions

    DEFF Research Database (Denmark)

    Zhai, Xu

    Root exudates from wetland plants have both positive and negative interactions among microbe, plants and ecosystems. Wetland species releasing organic carbon into the rhizosphere for providing energy to denitrifying bacteria fuel denitrification for removal nitrogen in subsurface flow constructed...... wetlands. Furthermore, environmental factors such as temperature and light-regime affect the photosynthetic carbon fixation, which continuously influence the compositions and quantity of root exudates released into rhizosphere. Conversely, root exudates from invasive species might contain some phytotoxic...... chemicals to suppress the growth of native species. Phragmites australis is recognized as the most invasive species in wetland ecosystems in North America, and allelopathy has been reported to be involved in the invasion success of the introduced exotic P. australis. The composition of the root exudates may...

  2. Level of catechin, myricetin, quercetin and isoquercitrin in buckwheat (Fagopyrum esculentum Moench), changes of their levels during vegetation and their effect on the growth of selected weeds.

    Science.gov (United States)

    Kalinova, Jana; Vrchotova, Nadezda

    2009-04-01

    Buckwheat is well-known as a crop rich in flavonoids, however, attention has usually only been paid to the main flavonoid rutin as an important natural antioxidant or as a possible allelopathic compound. Therefore, some of the other constituents found within individual plant parts of buckwheat (isoquercitrin, quercetin, catechin, and myricetin), as well as changes of their level during the growing season, were determined by HPLC analysis. The effects of these compounds on plant growth were proved on seven plant species. In buckwheat, isoquercitrin represented the largest component of the selected compounds. The strongest inhibitive effects on the growth of those selected plants were produced by catechin. Quercetin and isoquercitrin had weak inhibitive effects. Myricetin did not show any influence on plant growth. Hence we suppose that myricetin, isoquercetin and quercetin do not have important function in allelopathy of buckwheat. Buckwheat as row material for functional foods could be a significant source of another antioxidant, isoquercitrin.

  3. Effect of dissolved organic carbon quality on microbial decomposition and nitrification rates in stream sediments

    Science.gov (United States)

    Strauss, E.A.; Lamberti, G.A.

    2002-01-01

    1. Microbial decomposition of dissolved organic carbon (DOC) contributes to overall stream metabolism and can influence many processes in the nitrogen cycle, including nitrification. Little is known, however, about the relative decomposition rates of different DOC sources and their subsequent effect on nitrification. 2. In this study, labile fraction and overall microbial decomposition of DOC were measured for leaf leachates from 18 temperate forest tree species. Between 61 and 82% (mean, 75%) of the DOC was metabolized in 24 days. Significant differences among leachates were found for labile fraction rates (P bacteria, which then out-competed nitrifying bacteria for NH4+. White pine leachate probably increased heterotrophic metabolism and directly inhibited nitrification by allelopathy.

  4. Cogongrass (Imperata cylindrica invasions in the US: Mechanisms, impacts, and threats to biodiversity

    Directory of Open Access Journals (Sweden)

    James A. Estrada

    2015-01-01

    Full Text Available Invasions of non-native species can suppress biodiversity and alter ecosystem functions, but for many of the most widespread invasive species the mechanisms underlying their invasive success and effects on native species are poorly understood. Here we evaluated the peer-reviewed literature on causes and impacts of invasion by cogongrass (Imperata cylindrica, one of the most problematic invasive plant species in the southeast US. We assess what is known about why cogongrass is particularly invasive and how it affects native communities and ecosystems, review patterns in research methods employed, and provide a roadmap for future research on cogongrass. Although many studies have focused on the basic biology and management of cogongrass, we found surprisingly few (30 studies that have directly tested mechanisms or impacts of cogongrass invasions. The most commonly tested mechanisms, disturbance and allelopathy, were evaluated 4 and 12 times, respectively, and studies on invasion impacts were limited to five studies total: native plant diversity (2 studies, nitrogen cycling (2, decomposition (1, and fine fuel loads (1. Excluding laboratory studies on allelopathy, 75% (6/8 of impact studies used observational methods, raising questions about cause and effect. Given the paucity of studies on the ecology of cogongrass invasions, and the need to protect conservation areas from invasions, we urge that research efforts focus on: (1 environmental correlates of distribution and performance, (2 the role of propagule pressure in invasion success, (3 enemy release and post-introduction evolution as mechanisms of invasion, and (4 experimental tests of community and ecosystem impacts of invasions.

  5. Allelopathic activity of some grass species on Phleum pratense seed germination subject to their density

    Directory of Open Access Journals (Sweden)

    Halina Lipińska

    2012-12-01

    Full Text Available Efficient utilization of allelopathy in the agricultural practice requires searching for some species and developmental stages when the allelopathic substances are generated in bioactive concentrations. That also requires the knowledge of allelopathy mechanisms and primarily its separation from the other aspects of plant activity, mainly from competition for environmental resources. This task, however, has remained vital in the studies on plant interference, being extremely difficult to perform under field conditions. Therefore, the studies were conducted in the laboratory. To determine the activity of an allelopathic agent of the selected grass species, the density dependent phytotoxicity model was employed. The model is based on the fact that an increase of acceptor plants density evokes a decrease of their response to the allelopathic compounds, whereas the negative effects of the competition become more intense. A higher rate of acceptor plants growth accompanying their density increase in the given object does not agree with the competition rules and thus, it may imply an allelopathic background of the observed changes. In the presented studies, the allelopathic properties of grasses - donors were evaluated by studying the effect of two densities of the emerging seeds and two- and four weeks aged seedlings of F. arundinacea, L. multiflorum, L. perenne and P. pratensis. The tested species - acceptor Ph. pratensis was sown in the density of 10 and 20 seeds in a pan. The results revealed that the germination of acceptor seeds was differentiated depending on their density in the pan, and on the species, density and the age of the donor. Inhibition of Ph. pratense seed germination in objects with a lover density may prove allelopathic effects of the studied donor grasses.

  6. Vermicomposting transforms allelopathic parthenium into a benign organic fertilizer.

    Science.gov (United States)

    Hussain, Naseer; Abbasi, Tasneem; Abbasi, S A

    2016-09-15

    Vermicompost, which had been derived solely by the action of the epigeic earthworm Eisenia fetida on parthenium (Parthenium hysterophorus), was tested for its impact on the germination and early growth of green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). Seedlings were germinated and grown in soil amended with 0 (control), 0.75, 1.5, 2, 4, 8, 20 and 40% (by weight) parthenium vermicompost. Even though parthenium is known to possess strong negative allelopathy, as also plant/animal toxicity in other forms, its vermicompost (VC) manifested none of these attributes. Rather the VC enhanced germination success, introduced plant-friendly physical features in the container media, increased biomass carbon, and was seen to promote early growth as reflected in several morphological and biochemical characteristics in plants which had received parthenium VC in comparison to those which had not. All these effects were statistically significant. Fourier Transform Infrared (FTIR) Spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the negative allelopathic impact of parthenium were largely destroyed in the course of vermicomposting. FTIR spectra also indicated that lignin content of parthenium was reduced during its vermicomposting. The findings open up the possibility that several other invasives known for their negative allelopathy and toxicity may also produce vermicompost which may be plant-friendly and soil-friendly. It also makes it appear possible that the huge quantities of phytomass that is generated annually by parthenium can be gainfully utilized in producing organic fertilizer via vermicomposting, thereby providing a means of exercising some control over parthenium's rampant growth and invasion. PMID:27233043

  7. 核桃根系提取物对3种植物种子萌发和幼苗生长的化感作用%Allelopathic effects of root extracts from walnut on seed germination and seedling growth of three plant types

    Institute of Scientific and Technical Information of China (English)

    晏婷; 翟梅枝; 王元; 郝飞

    2012-01-01

    以核桃根系提取物对小麦(Triticum aestivums L.)、白菜(Brassica campestris L.)和绿豆(Phaseolus radiatus L.)3种受体种子萌发和幼苗生长的化感综合效应(synthesis effect,SE)为指标,确定核桃根系提取物最佳提取溶剂,并考察95%乙醇提取物不同萃取相的化感作用.结果表明:核桃根系95%乙醇提取物对3种受体的抑制作用最强(SE=-0.559);供试质量浓度为40mg/mL时,95%乙醇提取物不同萃取相对3种植物受体根长的抑制作用大于对苗高的抑制作用,其中乙酸乙酯萃取相的化感综合效应最强(SE=-0.571),对小麦、白菜根长和苗高的抑制率均达到60%以上,白菜种子最敏感.不同质量浓度乙酸乙酯萃取物对3种受体的化感作用强度不同,随萃取物质量浓度增加,小麦根长、苗高和相对含水量与对照相比均显著降低;白菜和绿豆的各指标表现出在低质量浓度时促进生长而高质量浓度时抑制生长的作用效果.%To determine the best extraction solvent of walnut roots, the allelopathic activities of root extracts from walnut were tested against wheat, cabbage and mung bean by the indicator of synthesis effect (SE) on seed germination and seedling growth. The allelopathy of different extraction phases from 95% ethanol extracts was also studied. The result showed that:95% ethanol extracts of walnut roots had the strongest inhibition on the seed germination and seedling growth of three acceptors (SE=—0. 559). When the tested mass concentration was 40 mg/mL,the inhibited effect of different extracts from 95% ethanol extracts on root length of three acceptors was greater than it on seedling height,with the most significant integrated allelopathy of ethyl acetate extracts (SE= —0. 571). The inhibition rate of root length and seedling height of wheat and cabbage was above 60 %; cabbage is more sensitive than wheat and mung bean. Different mass concentration treatments of ethyl acetate extracts

  8. Research Progress on Allelopathic Effects of Terrestrial Plants for Inhibitting Harmful Algae%陆生植物化感作用抑制有害藻应用研究进展

    Institute of Scientific and Technical Information of China (English)

    王聪; 张饮江; 李岩; 文晓峰; 董悦; 刘晓培; 马海峰

    2012-01-01

    The inhibitory allelopathy of plants on algae aroused extensive concern because of its high efficiency and selective character of inhibitting harmful algae,as well as harmless to the environment.lt is expected to be a valuable and safe ' alternative for algal bloom control with the intensive study .The progress of the inhibition on the harmful algae by allelopathy was introduced, the evaluation methodology of allelopathic effect were analyzed from aspects of algae cell density, chlorophyll content, growth and metabolism and ultrastmcture, antioxidant enzyme activities. The inhibition of water boom algae and red tide algae by terrestrial plants were mainly described, Some herbaceous plants such as crops and medicinal herb as well as some ligneous plants such as common trees were included in these terrestrial plants.The antialgal compounds in these terrestrial plants were explored and analyzed,which provide theoretical guidence for developing new algistat. The potential value of inhibiting filamentous algae by allelochemicals was further discussed, which achieved diversity of algal-inhibiting objects.The problem of allelopathy by terrestrial plants were pionted out and the prospect of allelopathic algae control was put forward.%植物化感物质由于对藻类抑制的高效性和选择作用性,以及对环境无污染等特点而备受关注,有望成为具有应用价值的安全性生物抑藻技术.文章探究了利用植物化感作用抑制有害藻类生长的进展,从藻细胞密度、叶绿素含量、超微结构及生长代谢、抗氧化酶活性等方面分析了化感抑藻作用效果的评价方法,重点阐述了陆生植物对水华藻、赤潮藻主要藻种的抑制作用,包括草本植物中一些农作物和药用植物以及木本植物中的常见树木,同时对这些陆生植物中所含抑藻物质开展了探索与分析,为开发新的抑藻制剂提供理论指导,深入讨论了陆生植物化感物质抑

  9. 芦笋不同组织水浸提液对辣椒的化感效应%Allelopathic Effect of Water Extracts from Different Parts of Asparagus officinalis L.on Hot Pepper

    Institute of Scientific and Technical Information of China (English)

    严泽生; 徐冬梅; 贺忠群

    2011-01-01

    [目的]测定芦笋不同组织浸提液对辣椒的化感效应.[方法]以辣椒为侵体,通过测定芦笋不同部分水浸提液对辣椒种子萌芽和幼苗生长的影响,研究芦笋对辣椒的化感效应.[结果]芦笋地上部和地下部组织水浸提液对辣椒种子发芽率、发芽指数均表现出抑制作用;高浓度芦笋地上部和地下部组织水浸提液对辣椒幼苗的生长及叶绿素含量均具有抑制作用,而低浓度浸提液具有促进作用.芦笋不同组织部位水浸提液的化感作用强弱不同,地上部分水浸提液化感作用明显强于地下部分.[结论]该研究为选择芦笋的间作作物及其秸杆的再利用提供了依据.%[ Objective ] To discuss the allelopathic effect of water extracts from different parts of Allelopathy of Asparagus officinalis L. On hot pepper. [Method] Using hot pepper as the receptor, effect of water extracts from different parts of Asparagus officinalis L. On seed germination and seedling growth were determined, investigating the allelopathy of Asparagus officinalis L. To hot pepper. [ Result ] Water extracts of aboveground and underground parts of Asparagus officinalis L. Showed inhibitory effect on germination rate and germination index of hot pepper. High concentration water extracts all showed inhibitory effect on seedling growth and content of chlorophyll,while low concentration ones presented facilitating effect on them. In addition, ailelopathic effect of water extracts from above ground of Asparagus officinalis L. Was stronger than that from under ground. [ Conclusion] This work is of considerable value for selection of interculture of Asparagus officinalis L. And reuse of straw of it.

  10. 赤潮异弯藻对孔石莼生长及其某些生理特性的影响%Effects of Heterosigma akashiwo (Hada) Hada on the growth and physiological characteristics of Ulva pertusa Kjellm

    Institute of Scientific and Technical Information of China (English)

    蔡恒江; 李博; 刘长发

    2012-01-01

    通过实验生态学和生物化学的方法,研究了赤潮异弯藻[ Heterosigma akashiwo (Hada) Hada]对孔石莼(Ulva pertusa Kjellman)生长及其叶绿素a(Chl-a)含量、丙二醛(MDA)含量、总抗氧化能力(T-AOC)、过氧化氢酶(CAT)活力、超氧化物歧化酶(SOD)活力和谷胱甘肽过氧化酶(GPX)活力的影响.结果表明:孔石莼的克生作用会明显抑制赤潮异弯藻的生长,同时赤潮异弯藻也会抑制孔石莼的生长,且孔石莼生理生化特性对其有明显的响应.赤潮异弯藻会使孔石莼CAT活力和MDA含量呈现升高的趋势;GPX活力呈现下降的趋势;T-AOC和T-SOD活力呈现先下降后升高趋势;Chl-a含量并无明显变化.推测赤潮异弯藻克生作用诱导孔石莼产生活性氧自由基,是藻体受损伤的主要原因.%The effects of Heterosigma akashiwo ( Hada) Hada on the growth,physiological characteristics including Chl-a content,MDA content,T-AOC,CAT activity,SOD activity and GPX activity of Ulva pertusa Kjellman were studied by experimental ecology and biochemical methods.The results demonstrated that U.pertusa could inhibit the growth of H.akashiwo,and H.akashiwo could inhibit the growth of U.pertusa simultaneously.The effects of U.perlusa on physiological characteristics were obvious.The MDA content and,CAT activity showed increasing trend,but GPX activity showed decreasing trend while T-AOC and T-SOD showed decreasing trend from 3d to 6d and increasing trend from 9d to 12d under allelopathy from H.akashiwo.The change of Chl-a content was not obvious.Superfluous reactive oxygen species produced by allelopathy from H.akashiwo was main reasons for the damage of U.pertusa.

  11. Effect of water extracts of larch on growth of Manchurian walnut seedlings%落叶松水浸液对胡桃楸幼苗生长的影响

    Institute of Scientific and Technical Information of China (English)

    杨立学

    2005-01-01

    A study was conducted to detect the effect of water extracts from different parts such as root, bark, branch and leaf, of adult larch, Larix gmelini, trees on growth of Manchurian walnut, Juglans mandshurica, seedlings and the allelopathy between the two tree species. Four concentrations (100 g·kg-1, 50 g·kg-1, 25 g·kg-1 and 12.5 g·kg-1) were prepared for each kind of extracts. Result showed that the water extracts with low and moderate concentrations accelerated the growth of collar diameter and increased biomass and root/shoot ratio of walnut seedlings. The water extracts from branches and barks with low and moderate concentrations accelerated the height growth of the seedlings, while those from leaves and roots slightly decreased the height growth of seedlings. The fact that application of water extracts of larch improved the growth of Manchurian walnut attributes possibly to the allelopathy between the two tree species.%利用落叶松根、皮、枝、叶等不同部位的水浸液处理胡桃楸的幼苗,研究了不同浓度(100 g·kg-1, 50 g·kg-1, 25 g·kg-1 and 12.5 g·kg-1)的水浸液对胡桃楸生长的影响及落叶松与胡桃楸之间的化感作用.结果表明低、中浓度落叶松水浸液促进胡桃楸幼苗地径、生物量生长和根冠比的提高.低、中浓度落叶松枝、皮水浸液促进胡桃楸幼苗株高生长,落叶松叶、根水浸液使胡桃楸幼苗株高生长略受抑制.施加落叶松水浸液对胡桃楸幼苗生长所起的促进作用可能与树种间的化学相互作用有关.图4参20.

  12. Emerging Insights on Brazilian Pepper Tree (Schinus terebinthifolius) Invasion: The Potential Role of Soil Microorganisms.

    Science.gov (United States)

    Dawkins, Karim; Esiobu, Nwadiuto

    2016-01-01

    Invasive plant species constitute a major ecological and economic problem worldwide, often distorting trophic levels and ecosystem balance. Numerous studies implicate factors ranging from environmental plasticity, competition for nutrient and space, and allelopathy in the success of invasive species in general. The Brazilian Pepper tree (BP) was introduced to the United States in the 1800s and has since become a category one invasive plant in Florida. It has aggressively spread to about 3000 km(2) of terrestrial surface, fueled in part by the prevalence of the hybrid genotypes and environmental perturbations. It displays some of the well-established invasive mechanisms but there is a serious dearth of knowledge on the plant-microbe-soil interactions and whether the rhizobiome plays any roles in the displacement of native flora and the range expansion of BP. Several control measures, including chemical, mechanical, and biological antagonism have been used with limited success while restoration of natives in soils from which BP was removed has proved problematic partly due to a poorly understood phenomenon described as the "BP legacy effect." Emerging evidence suggests that allelopathy, selective recruitment of beneficial soil microbes, disruption of microbial community structure and alteration of nutrient cycling, exhibited by many other invasive plant species may also be involved in the case of BP. This brief review discusses the well-established BP invasion mechanisms and highlights the current understanding of the molecular, below-ground processes. It also points out the gaps in studies on the potential role of microbial interactions in the success of BP invasion. These hitherto poorly studied mechanisms could further explain the aggressive spread of BP and could potentially contribute significantly to effective control measures and enable appropriate strategies for restoring native plants. The review advocates for the use of cutting-edge techniques in advancing

  13. Emerging insights on Brazilian Pepper tree (Schinus terebinthifolius invasion : the potential role of soil microorganisms

    Directory of Open Access Journals (Sweden)

    Karim eDawkins

    2016-05-01

    Full Text Available Invasive plant species constitute a major ecological and economic problem worldwide, often distorting trophic levels and ecosystem balance. Numerous studies implicate factors ranging from environmental plasticity, competition for nutrient and space, and allelopathy in the success of invasive species in general. The Brazilian Pepper tree (BP was introduced to the United States in the 1800s and has since become a category one invasive plant in Florida. It has aggressively spread to about 3000 km2 of terrestrial surface, fueled in part by the prevalence of the hybrid genotypes and environmental perturbations. It displays some of the well-established invasive mechanisms but there is a serious dearth of knowledge on the plant-microbe-soil interactions and whether the rhizobiome plays any roles in the displacement of native flora and the range expansion of BP. Several control measures, including chemical, mechanical and biological antagonism have been used with limited success while restoration of natives in soils from which BP was removed has proved problematic partly due to a poorly understood phenomenon described as the BP legacy effect. Emerging evidence suggests that allelopathy, selective recruitment of beneficial soil microbes, disruption of microbial community structure and alteration of nutrient cycling, exhibited by many other invasive plant species may also be involved in the case of BP. This brief review discusses the well-established BP invasion mechanisms and highlights the current understanding of the molecular, below-ground processes. It also points out the gaps in studies on the potential role of microbial interactions in the success of BP invasion. These hitherto poorly studied mechanisms could further explain the aggressive spread of BP and could potentially contribute significantly to effective control measures and enable appropriate strategies for restoring native plants. The review advocates for the use of cutting-edge techniques

  14. Efeito alelopático e toxicidade frente à Artemia salina Leach dos extatos do fruto de Euterpe edulis Martius Allelopathic effects and toxicity against Artemia salina Leach of extracts of the fruit of Euterpe edulis Martius

    Directory of Open Access Journals (Sweden)

    Cristina Peitz de Lima

    2011-06-01

    Full Text Available Alelopatia é um processo envolvendo metabólitos secundários produzidos por plantas que infl uenciam o crescimento e desenvolvimento de sistemas agrícolas. Devido à toxicidade dos herbicidas sintéticos para o meio ambiente e para a saúde humana tem-se aumentado o interesse na exploração da alelopatia como uma alternativa para o controle de plantas daninhas. O presente trabalho avaliou efeito dos extratos dos frutos de Euterpe edulis Martius sobre o desenvolvimento de cipselas e plântulas de Lactuca sativa Linné, foram determinados o índice de velocidade de germinação, o crescimento da radícula e do hipocótilo. Para a avaliação da toxicidade dos extratos foi realizado o ensaio de toxicidade frente ao microcrustáceo Artemia salina Leach determinando-se a CL50 e percentual de mortalidade. A fração remanescente demonstrou efeito alelopático, pois todas as concentrações alteraram os valores do índice de velocidade de germinação e as concentrações de 0,2 e 0,4 mg inibiram tanto o crescimento da radícula quanto o crescimento do hipocótilo. No ensaio de toxicidade todos os extratos apresentaram CL50 superior a 1000 ppm e 0% de mortalidade das artemias, indicando a não toxicidade dos extratos.Allelopathy is a process involving secondary metabolites produced by plants that influence growth and development of agricultural systems. Because of the toxicity of synthetic herbicides to the environment and human health, there has been increased interest in exploiting allelopathy as an alternative for weed control. This study evaluated the eff ect of extracts of Euterpe edulis Martius fruits on the development of cypselae and seedlings of Lactuca sativa Linné; the germination speed index, radicle and hypocotyl growth were determined. To evaluate the toxicity of the extracts the toxicity test against Artemia salina Leach was used, where the LC50 and mortality rate were determined. Th e remaining fraction showed allelopathic effect

  15. Ingredients for protist coexistence: competition, endosymbiosis and a pinch of biochemical interactions.

    Science.gov (United States)

    Müller, Johann P; Hauzy, Céline; Hulot, Florence D

    2012-01-01

    1. The interaction between mutualism, facilitation or interference and exploitation competition is of major interest as it may govern species coexistence. However, the interplay of these mechanisms has received little attention. This issue dates back to Gause, who experimentally explored competition using protists as a model [Gause, G.F. (1935) Vérifications expérimentales de la théorie mathématique de la lutte pour la vie. Actualités Scientifiques et Industrielles, 277]. He showed the coexistence of Paramecium caudatum with a potentially allelopathic species, Paramecium bursaria. 2. Paramecium bursaria hosts the green algae Chlorella vulgaris. Therefore, P. bursaria may benefit from carbohydrates synthesised by the algae. Studying endosymbiosis with P. bursaria is possible as it can be freed of its endosymbiont. In addition, C. vulgaris is known to produce allelochemicals, and P. bursaria may benefit also from allelopathic compounds. 3. We designed an experiment to separate the effects of resource exploitation, endosymbiosis and allelopathy and to assess their relative importance for the coexistence of P. bursaria with a competitor that exploits the same resource, bacteria. The experiment was repeated with two competitors, Colpidium striatum or Tetrahymena pyriformis. 4. Results show that the presence of the endosymbiont enables the coexistence of competitors, while its loss leads to competitive exclusion. These results are in agreement with predictions based on resource equilibrium density of monocultures (R*) supporting the idea that P. bursaria's endosymbiont is a resource provider for its host. When P. bursaria and T. pyriformis coexist, the density of the latter shows large variation that match the effects of culture medium of P. bursaria. Our experiment suggests these effects are because of biochemicals produced in P. bursaria culture. 5. Our results expose the hidden diversity of mechanisms that underlie competitive interactions. They thus support

  16. Allelopathic Sensitivity of Five Economic Species to Aqueous Leaf Extract of Eucalyptus urophylla × E.grandis with Different Ages%5种经济植物对幼龄尾巨桉叶片提取液的化感敏感性

    Institute of Scientific and Technical Information of China (English)

    王小雪; 刘芸; 邵呈龙; 唐小荐; 黄小辉; 吴艳冰; 唐吉芳; 何炳辉

    2011-01-01

    近几年,随着重庆"森林工程"全面启动,重庆西部主要区县充分利用当地有利自然条件,大规模发展速生桉树人工用材林.种植桉树需5年以上才能产生经济效益,因此,开展幼龄林林下种植成为以短养长、提高桉农收益的有效途径.但很多研究发现:桉树不仅具有较强的水、肥竞争力,而且作为一种外来树种,化感作用为其在新生境的生长和繁殖提供了"Novel weapon"(Bais et al.,2003;Hierro et al.,2003;吴锦容等,2005).%In order to guide scientifically planting on forest floor in eucalyptus plantations, screen suitable plants, and understand allelopathic effects of eucalyptus trees with different young ages (1 a, 2 a and 3 a) on the understory species and growth germination rate and seedling growth of five species widely planted in the local region were measured after treatments with different concentration of aqueous leaf extract of Eucalyptus urophylla × E. Grandis treatments with different concentration. The results showed that the leaf extract reduced seed germination rate and inhibited seedling growth of all five species, and had a stronger inhibiting effect on radical than hypocotyl growth. The species tested in this study had different sensitivity to the leaf extract. The inhibition rate of Lolium perenne, Sorghum sudanense, Phaseolus aureus, Phaseolus vulgaris and Glycine max was 56. 85% , 54. 58% , 33. 48% , 20. 81% , 16. 01% , respectively, among which Giycine max and Phaseolus vulgaris were the most insensitive to the leaf extract. The allelopathy of the leaf extract was concentration dependent, increasing with increase of the concentration, and low concentration (0.01 g · mL-1 ) had no significant influence on the species. Furthermore, the allelopathy aqueous leaf extract of E. Urophylla × E. Grandis to the five species had no significant difference with increase of their ages.

  17. Photosynthetic electron-transfer reactions in the gametophyte of Pteris multifida reveal the presence of allelopathic interference from the invasive plant species Bidens pilosa.

    Science.gov (United States)

    Zhang, Kai-Mei; Shen, Yu; Zhou, Xiao-Qi; Fang, Yan-Ming; Liu, Ying; Ma, Lena Q

    2016-05-01

    To date, the response of the fern gametophyte to its environment has received considerable attention. However, studies on the influence of plant invasion on the fern gametophyte are fewer. Allelopathy has been hypothesized to play an important role in biological invasion. Hence, it is necessary to study the allelopathy of invasive plant species to the fern gametophyte and elucidate the mechanisms by which invasive plants cause phytotoxicity. As one of the main invasive plants in China, Bidens pilosa exhibits allelopathic effects on the gametophytic growth of Pteris multifida. The root exudate plays an important role among various allelochemical delivery mechanisms in B. pilosa. The effect invasive plant species has on photosynthesis in native species is poorly understood. To elucidate this effect, the changes in photosynthesis in the gametophytes of P. multifida are analyzed to examine the mechanisms of the root exudates of B. pilosa. Meanwhile, a non-invasive plant, Coreopsis basalis, was also applied to investigate the effects on fluorescence and pigments in P. multifida gametophytes. We found that gametophytes exposed to both B. pilosa and C. basalis had decreased fluorescence parameters in comparison with the control, except for non-photochemical quenching. Furthermore, it was found that these parameters were markedly affected from day 2 to day 10 in the presence of both exudates at a concentration of 25% or above. B. pilosa exudate had a negative dose-dependent effect on chlorophyll a, chlorophyll b, carotenoid, and the total chlorophyll in the gametophyte. The inhibitory effects increased with increasing exudate concentrations of both species, exhibiting the greatest inhibition at day 10. In conclusion, B. pilosa irreversibly affected the photosynthesis of P. multifida on both PS I and PS II. Root exudates caused the primary damage with respect to the decrease of the acceptors and donors of photon and electron in photosynthetic units and the production and

  18. Atividade alelopática da leucena sobre espécies de plantas daninhas Allelopathic activity of leucaena on weed species

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    Nádja de Moura Pires

    2001-03-01

    Full Text Available Alelopatia é o efeito direto ou indireto de uma planta sobre outra, por meio da produção de compostos químicos liberados no ambiente. Os metabólitos secundários ou produtos naturais envolvidos em alelopatia são denominados aleloquímicos e estão presentes nos tecidos de diferentes partes das plantas. O objetivo deste trabalho foi determinar o potencial alelopático da leucena (Leucaena leucocephala (Lam. de Wit. sobre as plantas daninhas Desmodium purpureum (desmódio, Bidens pilosa (picão-preto e Amaranthus hybridus (caruru. Os bioensaios foram conduzidos em laboratório e em casa de vegetação com extratos aquosos da parte aérea da leucena nas concentrações de 100, 50, 25, 12,5 % (v v-1. O extrato apresentou maior efeito quando aplicado em papel filtro. O potencial alelopático da leucena variou com a espécie de planta daninha, sendo o picão-preto e o caruru as espécies mais sensíveis ao extrato em ambos os bioensaios. A mimosina foi quantificada por HPLC em concentrações diretamente correlacionadas à concentração do extrato, indicando ser este aleloquímico o provável responsável pelo efeito sobre a germinação e o desenvolvimento das plantas daninhas.Allelopathy is the direct or indirect effect of one plant on another through substances liberated into the environment, and occurs widely in natural plant communities. The secondary metabolites or natural products involved in allelopathy are called allelochemicals and can be produced in different parts of the plants. The purpose of this study was to determine the allelopathic potential of the aerial part of Leucaena leucocephala on the weeds Desmodium purpureum, Bidens pilosa and Amaranthus hybridus. Bioassays were carried out in laboratory and in greenhouse with aqueous extracts of the aerial part of leucaena in concentrations of 100, 50, 25, 12.5 % (v v-1. The aqueous extract showed major effect over the weeds when applied to filter paper. The allelopathic potential of

  19. Fate of allelochemicals in the soil Destino de aleloquímicos no solo

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    Ribas Antonio Vidal

    1997-06-01

    Full Text Available Allelochemicals are compounds released by one plant or plant residues that may have a negative or positive effect on other plant. The importance of allelopathy was extensively explored during the past three decades, with the work concentrating in the extraction and identification of the chemicals, and demonstration of activity in petry dish experiments. These compounds interact in the soil environment similarly as herbicides and are subject to processes of degradation such as microbial degradation, oxidation, and photolysis, and processes of removal or transfer, such as volatilization and adsorption. The objective of this review was to access the fate of allelochemicals in the soil environment to help to find strategies to increase its activity. The activity of allelochemical is limited in time (because of slow release from the donor material and in space (because of the interaction with the environment. Demonstration of allelopathy should include the fate of the proposed chemical in the soil environment, presenting studies of degradation and removal processes.Aleloquímicos são compostos liberados por plantas ou seus resíduos e que podem ter efeito negativo ou positivo em outra planta. A importância da alelopatia foi estudada intensamente nas últimas três décadas, sendo que a maioria dos trabalhos abordou a extração e identificação dos compostos e, demonstração de seus efeitos em experimentos realizados em placas de petri. Estes químicos interagem no ambiente assim como os herbicidas e estão sujeitos aos processos de degradação por decomposição microbiana, fotólise e oxidação e, processos de remoção ou transferência como volatilização e adsorção. O objetivo desta revisão de literatura foi estudar o destino de aleloquímicos no ambiente para auxiliar na definição de estratégias para aumentar sua atividade. A atividade dos aleloquímicos é limitada pelo tempo (devido a liberação lenta do material doador e pelo

  20. ATIVIDADE ALELOPÁTICA DE EXTRATOS DE PLANTAS DE COBERTURA SOBRE SOJA, PEPINO E ALFACE

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    JOSELI VIVIANE DITZEL NUNES

    2014-01-01

    Full Text Available Allelopathy can be defined as any effect , direct or indirect, beneficial or harmful, a plant on the other, through the release of chemical compounds into the environment. Thus, this study aimed at evaluat- ing, in the laboratory, allelopathic effects of aqueous extracts from cover crops as canola (Brassica napus L. var, crambe (Crambe abyssinica Hochst, sunn hemp (Crotalaria juncea, linseed (Linum usitatissimum L. and forage turnip (Raphanus sativus L. at 0, 12.5, 25, 50 and 100% concentrations. The plants used in aqueous extracts were collected during their flowering period of each studied species. Germination tests were performed on seeds gerbox, fresh and dry seedlings biomass, root and shoots seedlings length. The experimental design was completely randomized (CRD in factorial (5x5 with four replicates per treatment. According to these results, it can be concluded that the tested extracts showed allelopathic effect on seedlings of lettuce, cucumber and soybean on almost all parameters, but for soybean germination and dry mass percentage, this effect was not significant. The sunn hemp extract, despite concentration, contributed the most to increased germination and seedling growth. However, linseed extract showed opposite effect for these parameters in 100% concentrations.

  1. Bioscreening of Oxypeucedanin, a Known Furanocoumarin

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    Seyed Mehdi Razavi

    Full Text Available Objective(sAs an important class of natural products, coumarins exhibit many biological activities and the diversity of their bioactivity is so huge that the pharmacological promiscuity has been applied on their case. Oxypeucedanine also named as prangolarin is a linear furanocoumarin with an oxygenated prenylated substitution at C-5 of the nucleus. To our knowledge, there are few reports on pharmacological and biological activities of this compound. In the present work, we focused on some bioactive aspects of it.Materials and MethodsIn the present work, the compound was purified from Prangos uloptera using TLC and its phytotoxic, antibacterial, antifungal, antioxidant and cytotoxic effects were evaluated by Lettuce assay, disc diffusion method, mycelia radial growth, DPPH and MTT assays, respectively.Results Our results revealed that oxypeucedanin exhibit considerable phytotoxic activity and might play an allelopathic role for plants. The compound indicated high cytotoxic activity with IC50 value of 314 µg/ml. No antipathogenic and antioxidant activity were found for oxypeucedanin in this study. ConclusionWe conclude that oxypeucedanin (found in some vegetables can be considered as an antiproliferative agent. Keywords: Allelopathy, Antiproliferative agent, Cytotoxic activity, Oxypeucedanin, Phytotoxic activity, Prangos uloptera

  2. Programmed Cell Death in Unicellular Phytoplankton.

    Science.gov (United States)

    Bidle, Kay D

    2016-07-11

    Unicellular, planktonic, prokaryotic and eukaryotic photoautotrophs (phytoplankton) have an ancient evolutionary history on Earth during which time they have played key roles in the regulation of marine food webs, biogeochemical cycles, and Earth's climate. Since they represent the basis of aquatic ecosystems, the manner in which phytoplankton die critically determines the flow and fate of photosynthetically fixed organic matter (and associated elements), ultimately constraining nutrient flow. Programmed cell death (PCD) and associated pathway genes, which are triggered by a variety of abiotic (nutrient, light, osmotic) and biotic (virus infection, allelopathy) environmental stresses, have an integral grip on cell fate, and have shaped the ecological success and evolutionary trajectory of diverse phytoplankton lineages. A combination of physiological, biochemical, and genetic techniques in model algal systems has demonstrated a conserved molecular and mechanistic framework of stress surveillance, signaling, and death activation pathways, involving collective and coordinated participation of organelles, redox enzymes, metabolites, and caspase-like proteases. This mechanistic understanding has provided insight into the integration of sensing and transduction of stress signals into cellular responses, and the mechanistic interfaces between PCD, cell stress and virus infection pathways. It has also provided insight into the evolution of PCD in unicellular photoautotrophs, the impact of PCD on the fate of natural phytoplankton assemblages and its role in aquatic biogeochemical cycles. PMID:27404255

  3. The Effect of Dissolved Polyunsaturated Aldehydes on Microzooplankton Growth Rates in the Chesapeake Bay and Atlantic Coastal Waters

    Directory of Open Access Journals (Sweden)

    Peter J. Lavrentyev

    2015-05-01

    Full Text Available Allelopathy is wide spread among marine phytoplankton, including diatoms, which can produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA. Most studies on diatom-produced PUA have been dedicated to their inhibitory effects on reproduction and development of marine invertebrates. However, little information exists on their impact on key herbivores in the ocean, microzooplankton. This study examined the effects of dissolved 2E,4E-octadienal and 2E,4E-heptadienal on the growth rates of natural ciliate and dinoflagellate populations in the Chesapeake Bay and the coastal Atlantic waters. The overall effect of PUA on microzooplankton growth was negative, especially at the higher concentrations, but there were pronounced differences in response among common planktonic species. For example, the growth of Codonella sp., Leegaardiella sol, Prorodon sp., and Gyrodinium spirale was impaired at 2 nM, whereas Strombidium conicum, Cyclotrichium gigas, and Gymnodinium sp. were not affected even at 20 nM. These results indicate that PUA can induce changes in microzooplankton dynamics and species composition.

  4. Momilactone sensitive proteins in Arabidopsis thaliana.

    Science.gov (United States)

    Kato-Noguchi, Hisashi; Kitajima, Shinya

    2015-05-01

    The labdane-related diterpenoid, momilactone B has potent growth inhibitory activity and was demonstrated to play a particularly critical role in the allelopathy of rice (Oryza sativa L.). However, there is limited information available about the mode of action of momilactone B on the growth inhibition. The present research describes the effects of momilactone B on protein expression in the early development of Arabidopsis thaliana seedling, which was determined by two-dimensional electrophoresis and MALDI-TOFMS. Momilactone B inhibited the accumulation of subtilisin-like serine protease, amyrin synthase LUP2, β-glucosidase and malate synthase at 1 h after the momilactone application. Those proteins are involved in the metabolic turnover and the production of intermediates needed for cell structures resulting in plant growth and development. Momilactone B also inhibited the breakdown of cruciferin 2, which is essential for seed germination and seedling growth to construct cell structures. Momilactone B induced the accumulation of translationally controlled tumor protein, glutathione S-transferase and 1-cysteine peroxiredoxin 1. These proteins are involved in stress responses and increased stress tolerance. In addition, glutathione S-transferase has the activity of herbicide detoxification and 1-cysteine peroxiredoxin 1 has inhibitory activity for seed germination under unfavorable conditions. The present research suggests that momilactone B may inhibit the seedling growth by the inhibition of the metabolic turnover and the production of intermediates for cell structures. In addition, momilactone induced proteins associated with plant defense responses. PMID:26058145

  5. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon.

    Science.gov (United States)

    Chai, Min; Zhu, Xiaopei; Cui, Hongxia; Jiang, Chuangdao; Zhang, Jinzheng; Shi, Lei

    2015-01-01

    As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape) causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as 'trap crops' for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids 'Sorbonne', Lilium LA (Longiflorum hybrids x Asiatic hybrids) hybrids 'Ceb Dazzle', and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum) 'L. formolongo') to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced "suicidal germination" of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil. PMID:26565398

  6. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon.

    Directory of Open Access Journals (Sweden)

    Min Chai

    Full Text Available As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as 'trap crops' for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids 'Sorbonne', Lilium LA (Longiflorum hybrids x Asiatic hybrids hybrids 'Ceb Dazzle', and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum 'L. formolongo' to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced "suicidal germination" of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil.

  7. Phytotoxic effects of Calotropis procera (Ait. R. Br. extract on three weed plants

    Directory of Open Access Journals (Sweden)

    Gulzar, A.

    2014-11-01

    Full Text Available A study was conducted to determine the potential and nature of allelopathic interference of Calotropis procera on seed germination and seedling growth of three weed species (Ageratum conyzoides L., Cannabis sativa L. and Trifolium repens L. Aqueous extracts of Calotropis procera at 0.5, 1.0, 2.0 and 4.0% concentrations were applied to determine their effect on seed germination and seedling growth of test plants under laboratory conditions. The aqueous extracts had retardary effect on seed germination, root length and shoot length. Germination percentage, root length and shoot length of weed species decreased progressively when treated with increasing extract concentration (0.5, 1, 2 and 4%. The pH values did not increase at all extract concentrations. Therefore, the change in pH values in this experiment is not responsible for the inhibition of test species growth.The phenolic content analysed show more pronounced increase in its contents at 4% concentrations. The study concludes that C. procera releases phenolics into the extract and these are probably involved in the growth inhibitory effect, which causes allelopathy operative in the community dominated by C. procera and provide an advantage to the weed.

  8. [Inhibitory effect of Gracilaria lemaneformis (Bory) Weber Bosse on the co-cultured Scrippsiella trochoidea (Stein) Loeblich III under controlled laboratory conditions].

    Science.gov (United States)

    Zhang, Shan-dong; Song, Xiu-xian; Cao, Xi-hua; Yu, Zhi-ming

    2008-08-01

    The inhibitory effects of Grcilaria lemaneiformis on the co-cultured Scrippsiella trochoidea were determined under controlled laboratory conditions, and the possible mechanism was studied. Results showed that: (1) in the separating S. trochoiea-G. lemaneormis co-culture system when the initial cell density of C. lemaneaonis was set at 0.5 g x L(-1), the growth of S. trochoidea was obviously inhibited and its maximum cell density and exponential phase were decreased compared with the control; however, the inhibitory effect was not as strong as that in the direct cell-cell contact co-culture. Result showed that allelopathy basing on the direct cell contact was the most possible reason leading to the observed result; (2) when the initial cell density of G. lemaneiformis was set at 0.2 g'L-' in the direct cell-cell contact co-culture, the intracellular nitrate concentration of S. trochoidea in monoculture system was 1.5 times of that in co-culture. It seemed that G. lemaneiformis could competitively absorb the environmental nitrate and ultimately led to the decrease of the stock of intracellular nitrate of S. trochoidea.

  9. Allelopathic interactions between the opportunistic species Ulva prolifera and the native macroalga Gracilaria lichvoides.

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    Dong Xu

    Full Text Available Allelopathy, one type of direct plant competition, can be a potent mechanism through which plant communities are structured. The aim of this study was to determine whether allelopathic interactions occur between the opportunistic green tide-forming species Ulva prolifera and the native macroalga Gracilaria lichvoides, both of which were collected from the coastline of East China sea. In laboratory experiments, the presence of G. lichvoides at 1.25 g wet weight L(-1 significantly inhibited growth and photosynthesis of U. prolifera at concentrations of 1.25, 2.50, and 3.75 g wet weight L(-1 (p0.05. Culture medium experiments further confirmed that some allelochemicals may be released by both of the tested macroalgae, and these could account for the observed physiological inhibition of growth and photosynthesis. Moreover, the native macroalgae G. lichvoides was a stronger competitor than the opportunistic species U. prolifera. Collectively, the results of the present study represent a significant advance in exploring ecological questions about the effects of green tide blooms on the macroalgal community.

  10. Allelopathic interactions between the opportunistic species Ulva prolifera and the native macroalga Gracilaria lichvoides.

    Science.gov (United States)

    Xu, Dong; Gao, Zhengquan; Zhang, Xiaowen; Fan, Xiao; Wang, Yitao; Li, Demao; Wang, Wei; Zhuang, Zhimeng; Ye, Naihao

    2012-01-01

    Allelopathy, one type of direct plant competition, can be a potent mechanism through which plant communities are structured. The aim of this study was to determine whether allelopathic interactions occur between the opportunistic green tide-forming species Ulva prolifera and the native macroalga Gracilaria lichvoides, both of which were collected from the coastline of East China sea. In laboratory experiments, the presence of G. lichvoides at 1.25 g wet weight L(-1) significantly inhibited growth and photosynthesis of U. prolifera at concentrations of 1.25, 2.50, and 3.75 g wet weight L(-1) (p0.05). Culture medium experiments further confirmed that some allelochemicals may be released by both of the tested macroalgae, and these could account for the observed physiological inhibition of growth and photosynthesis. Moreover, the native macroalgae G. lichvoides was a stronger competitor than the opportunistic species U. prolifera. Collectively, the results of the present study represent a significant advance in exploring ecological questions about the effects of green tide blooms on the macroalgal community.

  11. [Effects of Ulva pertusa and Gracilaria lemaneiformis on growth of Heterosigma akashiwo (Raphidophyceae) in co-culture].

    Science.gov (United States)

    Wang, You; Yu, Zhi-ming; Song, Xiu-xian; Zhang, Shan-dong

    2006-02-01

    We studied the effects of fresh tissue and culture medium filtrate of two species of macroalgae, Ulva pertusa (Chlorophyta) and Gracilaria lemaneiformis (Rhodophyta) on growth of Heterosigma akashiwo (Raphidophyceae) in co-culture. Both U. pertusa and G. lemaneiformis, and especially their fresh tissues, significantly impede the growth of H. akashiwo. Carbonate limitations and the presence of environment bacteria are not necessary for the negative effects of macroalgal on H. akashiwo. The simultaneous nutrient assays show that nitrate and phosphate are almost exhausted in the G. lemaneiformis co-culture system, but remain at acceptable levels in the U. pertusa system, when all cells of H. akashiwo are completely dead. When f/2 medium is supplied daily to G. lemaneiformis culture, the growth of H. akashiwo is greatly inhibited but not completely terminated. Furthermore, different amounts of fresh seaweed tissue, and culture medium filtrate prepared from different macroalgal concentrations are analyzed to determine their effects on the growth of H. akashiwo. The results show a positive correlation between the initial macroalgal concentration and the negative effects they exert on the co-cultured microalgae. Results suggest that the allelopathic effects of U. pertusa may be essential for negative effects on H. akashiwo; however, the combined roles of allelopathy and nutrient competition may be responsible for the negative effect of G. lemaneiformis the release of allelochemicals by U. pertusa.

  12. Effects of climate warming on plant autotoxicity in forest evolution: a case simulation analysis for Picea schrenkiana regeneration.

    Science.gov (United States)

    Ruan, Xiao; Pan, Cun-De; Liu, Run; Li, Zhao-Hui; Li, Shu-Ling; Jiang, De-An; Zhang, Jing-Chi; Wang, Geoff; Zhao, Yin-Xian; Wang, Qiang

    2016-08-01

    In order to explore how plant autotoxicity changes with climate warming, the autotoxicity of P. schrenkiana needles' water extract, organic extract fractions, and key allelochemical DHAP was systemically investigated at the temperature rising 2 and 4°C based on the data-monitored soil temperature during the last decade in the stage of Schrenk spruce regeneration (seed germination and seedling growth). The results showed that the criterion day and night temperatures were 12°C and 4°C for seed germination, and 14°C and 6°C for seedling growth, respectively. In the presence of water extract, the temperature rise of 2°C significantly inhibited the germination vigor and rate of P. Schrenkiana seed, and a temperature rise of 4°C significantly increased the inhibition to the seedling growth (P germination and growth even at low concentration of 0.1 mg/mL, and the inhibition effect was enhanced as temperature increased. The temperature rise significantly enhanced the promotion effect of DHAP, while the inhibition effect of temperature rise became less important with increasing concentration of DHAP. This investigation revealed that autotoxicity of P. schrenkiana was affected by the climate warming. As expected, it provided an insight into the mechanism and effectiveness of allelopathy in bridging the causal relationship between forest evolution and climate warming. PMID:27547360

  13. Sesquiterpenoids Lactones: Benefits to Plants and People

    Directory of Open Access Journals (Sweden)

    Carol Wagstaff

    2013-06-01

    Full Text Available Sesquiterpenoids, and specifically sesquiterpene lactones from Asteraceae, may play a highly significant role in human health, both as part of a balanced diet and as pharmaceutical agents, due to their potential for the treatment of cardiovascular disease and cancer. This review highlights the role of sesquiterpene lactones endogenously in the plants that produce them, and explores mechanisms by which they interact in animal and human consumers of these plants. Several mechanisms are proposed for the reduction of inflammation and tumorigenesis at potentially achievable levels in humans. Plants can be classified by their specific array of produced sesquiterpene lactones, showing high levels of translational control. Studies of folk medicines implicate sesquiterpene lactones as the active ingredient in many treatments for other ailments such as diarrhea, burns, influenza, and neurodegradation. In addition to the anti-inflammatory response, sesquiterpene lactones have been found to sensitize tumor cells to conventional drug treatments. This review explores the varied ecological roles of sesquiterpenes in the plant producer, depending upon the plant and the compound. These include allelopathy with other plants, insects, and microbes, thereby causing behavioural or developmental modification to these secondary organisms to the benefit of the sesquiterpenoid producer. Some sesquiterpenoid lactones are antimicrobial, disrupting the cell wall of fungi and invasive bacteria, whereas others protect the plant from environmental stresses that would otherwise cause oxidative damage. Many of the compounds are effective due to their bitter flavor, which has obvious implications for human consumers. The implications of sesquiterpenoid lactone qualities for future crop production are discussed.

  14. Chemically-mediated interactions between macroalgae Dictyota spp. and multiple life-history stages of the coral Porites astreoides

    Science.gov (United States)

    Paul, Valerie J.; Kuffner, Ilsa B.; Walters, Linda J.; Ritson-Williams, Raphael; Beach, Kevin S.; Becerro, Mikel A.

    2011-01-01

    Competition between corals and macroalgae is often assumed to occur on reefs, especially those that have undergone shifts from coral to algal dominance; however, data examining these competitive interactions, especially during the early life-history stages of corals, are scarce. We conducted a series of field and outdoor seawater-table experiments to test the hypothesis that allelopathy (chemical inhibition) mediates interactions between 2 common brown macroalgae, Dictyota pulchella and D. pinnatifida, and the coral Porites astreoides at different life-history stages of the coral. D. pinnatifida significantly reduced larval survival and larval recruitment. The extracts of both D. pinnatifida and D. pulchella significantly reduced larval survival, and the extract of D. pulchella also negatively influenced larval recruitment. There was no measurable effect of the crude extracts from Dictyota spp. on the photophysiology of adult corals. Our results provide evidence that these Dictyota species chemically compete with P. astreoides by negatively affecting larval settlement and recruitment as well as the survival of larvae and new recruits. Macroalgae may perpetuate their dominance on degraded reefs by chemically inhibiting the process of coral recruitment.

  15. Chemically mediated interactions between macroalgae Dictyota spp. and multiple life-history stages of the coral Porites astreoides

    Science.gov (United States)

    Paul, V.J.; Kuffner, I.B.; Walters, L.J.; Ritson-Williams, R.; Beach, K.S.; Becerro, M.A.

    2011-01-01

    Competition between corals and macroalgae is often assumed to occur on reefs, especially those that have undergone shifts from coral to algal dominance; however, data examining these competitive interactions, especially during the early life-history stages of corals, are scarce. We conducted a series of field and outdoor seawater-table experiments to test the hypothesis that allelopathy (chemical inhibition) mediates interactions between 2 common brown macroalgae, Dictyota pulchella and D. pinnatifida, and the coral Porites astreoides at different life-history stages of the coral. D. pinnatifida significantly reduced larval survival and larval recruitment. The extracts of both D. pinnatifida and D. pulchella significantly reduced larval survival, and the extract of D. pulchella also negatively influenced larval recruitment. There was no measurable effect of the crude extracts from Dictyota spp. on the photophysiology of adult corals. Our results provide evidence that these Dictyota species chemically compete with P. astreoides by negatively affecting larval settlement and recruitment as well as the survival of larvae and new recruits. Macroalgae may perpetuate their dominance on degraded reefs by chemically inhibiting the process of coral recruitment. ?? 2011 Inter-Research.

  16. Biosynthesis and molecular actions of specialized 1,4-naphthoquinone natural products produced by horticultural plants

    Science.gov (United States)

    Widhalm, Joshua R; Rhodes, David

    2016-01-01

    The 1,4-naphthoquinones (1,4-NQs) are a diverse group of natural products found in every kingdom of life. Plants, including many horticultural species, collectively synthesize hundreds of specialized 1,4-NQs with ecological roles in plant–plant (allelopathy), plant–insect and plant–microbe interactions. Numerous horticultural plants producing 1,4-NQs have also served as sources of traditional medicines for hundreds of years. As a result, horticultural species have been at the forefront of many basic studies conducted to understand the metabolism and function of specialized plant 1,4-NQs. Several 1,4-NQ natural products derived from horticultural plants have also emerged as promising scaffolds for developing new drugs. In this review, the current understanding of the core metabolic pathways leading to plant 1,4-NQs is provided with additional emphasis on downstream natural products originating from horticultural species. An overview on the biochemical mechanisms of action, both from an ecological and pharmacological perspective, of 1,4-NQs derived from horticultural plants is also provided. In addition, future directions for improving basic knowledge about plant 1,4-NQ metabolism are discussed. PMID:27688890

  17. Allelopathic effects of essential oil from Eucalyptus grandis × E.urophylla on pathogenic fungi and pest insects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This study on the allelopathic effects and chemical components of the essential oil from Eucalyptus grandis × E.urophylla shows that the leaf oil emulsion of E.grandis × E.urophylla can inhibit the proliferation of pathogenic fungi Fusarium oxysporum,Pyriculerie grisea,Glorosprium musa rum and Phytophthora capsici.Pupation and feeding of the pest insects Spodopteralitura Fabricius and Helicoverpa armigera Hubner are shown to be affected with restraining effects which increase with the increasing levels of oil concentration.A GC/MS analysis of the leaf oil indicated that the main components,with a relative content of≥3%,were alloocimene (43.22%),α-pinene (13.63%),γ-terpinene (5.49%),(E)-3,7-dimethyl-2,6-octadien-1-ol (3.58%),β-fenchyl alcohol (4.58%),and 2-amino-3,5-dicyano-6-(4-methoxyphenoxy)-pyridine (3.67%).Terpenes played an important role in the inhibitory effects of E.grandis × E.urophylla essential oil on pathogenic fungi and pest insects.Poor biodiversity of eucalyptus plantations is a function of allelopathy.

  18. Vermicomposting eliminates the toxicity of Lantana (Lantana camara) and turns it into a plant friendly organic fertilizer.

    Science.gov (United States)

    Hussain, N; Abbasi, Tasneem; Abbasi, S A

    2015-11-15

    In evidently the first study of its kind, vermicompost derived solely from a weed known to possess plant and animal toxicity was used to assess its impact on the germination and early growth of several plant species. No pre-composting or supplementation of animal manure was done to generate the vermicompost in order to ensure that the impact is clearly attributable to the weed. Whereas the weed used in this study, Lantana (Lantana camara), is known to possess strong negative allelopathy, besides plant/animal toxicity in other forms, its vermicompost was seen to be a good organic fertilizer as it increased germination success and encouraged growth of all the three botanical species explored by the authors - green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). In terms of several physical, chemical and biochemical attributes that were studied, the vermicompost appeared plant-friendly, giving best results in general when employed at concentrations of 1.5% in soil (w/w). Fourier transform infrared spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the allelopathic impact of Lantana were largely destroyed in the course of vermicomposting. There is also an indication that lignin content of Lantana was reduced during its vermicomposting. The findings open up the possibility that the billions of tons of phytomass that is generated annually by Lantana and other invasives can be gainfully utilized in generating organic fertilizer via vermicomposting. PMID:26073377

  19. Allelopathic influence of Phytolacca dioica L. germination and early growth of Lycopersicum esculentum and Bidens pilosa

    Directory of Open Access Journals (Sweden)

    Junior Borella

    2009-09-01

    Full Text Available Allelopathy refers to the ability that a plant has to interfere in the metabolism of another by means of chemical compounds released into the environment. The objective of this study was to determine the allelopathic effect of aqueous extracts of leaves of Phytolacca dioica L. on the germination and early growth of tomato plants and Bidens pilosa. Extracts were prepared at concentrations of 1%, 2%, 4% and 8%. We measured the pH and osmotic potential of the extracts and carried out a phytochemical analysis of the leaves. In our experiments we used four replicates of 25 seeds distributed in Petri dishes with two sheets of germitest paper dampened with 5mL extract. We evaluated the percentage of germination (PG, speed of germination (VG, speed of germination index (IVG, and length (root and shoot and mass (fresh and dry of seedlings of tomato and Bidens pilosa. The pH and osmotic potential were found to be within acceptable standards and the phytochemical analysis of the leaves showed the presence of flavonoids. PG, VG and IVG were affected in more concentrated treatments (4 and 8%, and the length and mass of seedlings of tomato and Bidens pilosa were affected in all treatments. Treatments at an 8% concentration completely inhibited the germination process of the plants.

  20. Interspecific variation in the allelopathic potential of the family Myrtaceae

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    Maristela Imatomi

    2013-03-01

    Full Text Available Allelopathy is a type of biotic interference wherein a plant releases bioactive metabolites into an environment, thereby affecting the adjacent biota. Stressful environments stimulate the production of these metabolites. The present study tests the novel weapons hypothesis, which postulates that species belonging to the same genus and from the same environment have similar allelopathic effects. The aim of this study was to assess the allelopathic effects that the aqueous leaf extracts of 15 species belonging to five genera of the Myrtaceae family have on the seed germination and initial seedling growth of lettuce (Lactuca sativa L., tomato (Solanum lycopersicum L. and onion (Allium cepa L.. Germination rates, average germination times, informational entropy of germination and allelopathic effects, as quantified with a response index, were calculated. A taxonomic distance matrix based on Gower dissimilarity and a Euclidean distance matrix were constructed. The results revealed that all extracts from donor species significantly increased average germination time or reduced the germination rate of eudicotyledonous plant species. The only extracts that showed no effect on monocotyledonous seeds were those of Campomanesia pubescens O. Berg and Psidium cinereum Mart. We conclude that eudicotyledonous and monocotyledonous plants were both significantly affected by the presence of all extracts tested. Our results make it clear that each species behaves distinctly in relation to allelopathic activity, with no apparent grouping by genus or subtribe. Therefore, the hypothesis was rejected, because plants from the same environment and with taxonomic proximity do not necessarily display similar production of secondary metabolites.

  1. Allelopathic interference of aqueous extracts of chinaberry on the germination and initial growth of tomato

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    Lindamir Hernandez Pastorini

    2012-09-01

    Full Text Available Allelopathy effects vegetative development and is caused by chemical substances produced and released by surrounding plants. The objective of this work was to investigate the allelopathic activity of aqueous extracts of fresh and dried leaves and fruits of chinaberry (Melia azedarach L. – Meliaceae on the germination and initial growth of tomato. The extracts were prepared at concentrations of 1, 2 and 4% and analyzed for their pH and osmotic potential. The experiment consisted of four replications of 25 tomato seeds that were distributed in Petri dishes containing two sheets of germitest paper. Each plate received 2mL of an extract. The seeds were evaluated for percentage of germination (PG, germination rate (VG and germination speed index (IVG. The initial growth was assessed based on the length of the radicle, hypocotyl and leaf, and fresh and dry weight. All concentrations of the extracts exhibited inhibitory activity on germination and radicle growth, and the inhibitory effect increased as the concentration of the extract increased. Extracts from dried leaves had the greatest effects. The osmotic potential and pH of the extracts did not vary significantly compared to the control, indicating that the allelopathic effect was due to the allelochemicals in the extracts.

  2. Seedling mortality from litterfall increases with decreasing latitude.

    Science.gov (United States)

    Gillman, Len N

    2016-02-01

    Global patterns in ecology need to be identified and interpreted if macroecological processes are to be fully understood. Facilitating effects on seedlings such as that of nurse plants and competitive effects such as allelopathy have been well recognized but the importance of plants acting as killers through physical damage by the litterfall they produce has received relatively little attention. Here I examine latitudinal patterns of physical disturbance to seedlings (microdisturbance) due to litterfall and discuss the macroecological implications in light of current research. Analyses of results from published studies show that both the risk of litterfall disturbance, as measured using artificial model seedlings, and the proportion of seedling mortalities due to litterfall decrease significantly with increasing latitude. Patterns of microdisturbance appear to be driven by the dynamic interaction between macro-litterfall, safe sites with protective overhead vegetation, topography, and animal activity. However, we are informed on this subject by few studies. There is evidence, again from a limited number of studies, for considerable spatial heterogeneity in microdisturbance intensity and for seedling resilience to litterfall damage to differ substantially among species. Therefore, differential survival among microsites may produce regeneration niche diversity. However, more focused studies are required across a range of forest types and latitudes before these results can be generalized. Therefore, there is fertile ground for researchers to use comparable multifactorial methods to investigate the implications of microdisturbance at macro-ecological scales. PMID:27145626

  3. Release from belowground enemies and shifts in root traits as interrelated drivers of alien plant invasion success: a hypothesis.

    Science.gov (United States)

    Dawson, Wayne

    2015-10-01

    Our understanding of the interrelated mechanisms driving plant invasions, such as the interplay between enemy release and resource-acquisition traits, is biased by an aboveground perspective. To address this bias, I hypothesize that plant release from belowground enemies (especially fungal pathogens) will give invasive plant species a fitness advantage in the alien range, via shifts in root traits (e.g., increased specific root length and branching intensity) that increase resource uptake and competitive ability compared to native species in the alien range, and compared to plants of the invader in its native range. Such root-trait changes could be ecological or evolutionary in nature. I explain how shifts in root traits could occur as a consequence of enemy release and contribute to invasion success of alien plants, and how they could be interrelated with other potential belowground drivers of invasion success (allelopathy, mutualist enhancement). Finally, I outline the approaches that could be taken to test whether belowground enemy release results in increased competitive ability and nutrient uptake by invasive alien plants, via changes in root traits in the alien range.

  4. Effets allélopathiques des Brassicacées via leurs actions sur les agents pathogènes telluriques et les mycorhizes : analyse bibliographique. Partie 1

    Directory of Open Access Journals (Sweden)

    Reau Raymond

    2005-05-01

    Full Text Available Brassicas contain glucosinolates (GSL which decomposition is able to reduce the growth of populations of soil-borne fungi, bacterias or nematodes. These biocid effects on soil-borne microorganisms make a form of allelopathy phenomenon. The allelopathic properties depends on the GLS composition of the Brassicas: Indian mustard and in a lower extend Oilseed rape could have the most powerfull action, White mustard would have a weaker action. These properties also depends on crop residues: green manure with quick decomposition would result with a higher action than crop residues after grain harvest. The main mechanisms are known. In vitro, isothiocyanates obtained from the GSL decomposition inhibit all the phases of the cycle of Aphanomyces eutiches, the fungus responsible for root rot of peas. The mycelian growth of Gaeumannomyces graminis tritici, the fungus responsible for the wheat take all is inhibited by some isothyocyanates at low concentration. Furthermore, several studies give the evidence that the incorporation of Brassicas residues into the soil does inhibit the growth of both soil-borne pathogens. At last, the presence of roots of Brassicas inhibits the germination of the mycorhizes known to improve the mineral nutrition of its host plant. This phenomenon could explain the depressive effect of oilseed rape on the nutrition of a subsequent maize. This knowledge of Brassicas effects into cropping systems offers issues for a better management of precedent effects of Brassicas; these effects being positive (integrated cop protection or negative (management of subsequent crop nutrition after Brassicas.

  5. Effets allélopathiques des Brassicacées via leurs actions sur les agents pathogènes telluriques et les mycorhizes : analyse bibliographique. Partie II

    Directory of Open Access Journals (Sweden)

    Reau Raymond

    2005-07-01

    Full Text Available Brassicas contain glucosinolates (GSL which decomposition is able to reduce the growth of populations of soil-borne fungi, bacterias or nematodes. These biocid effects on soil-borne microorganisms make a form of allelopathy phenomenon. The allelopathic properties depends on the GLS composition of the Brassicas: Indian mustard and in a lower extend Oilseed rape culd have the most powerfull action, White mustard would have a weaker action. These properties also depends on crop residues: green manure with quick decomposition would result with a higher action than crop residues after grain harvest.The main mechanisms are known. In vitro, isothiocyanates obtained from the GSL decomposition inhibit all the phases of the cycle of Aphanomyces eutiches, the fungus responsible for root rot of peas. The mycelian growth of Gaeumannomyces graminis tritici, the fungus responsible for the wheat take all is inhibited by some isothyocyanates at low concentration. Furthermore, several studies give the evidence that the incorporation of Brassicas residues into the soil does inhibit the growth of both soil-borne pathogens. At last, the presence of roots of Brassicas inhibits the germination of the mycorhizes known to improve the mineral nutrition of its host plant. This phenomenon could explain the depressive effect of oilseed rape on the nutrition of a subsequent maize.This knowledge of Brassicas effects into cropping systems offers issues for a better management of precedent effects of Brassicas; these effects being positive (integrated cop protection or negative (management of subsequent crop nutrition after Brassicas.

  6. Allelopathic Effects of Invasive Woody Plant Species in Hungary

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    CSISZÁR, Ágnes

    2009-01-01

    Full Text Available Allelopathy may play an important role in the invasion success of adventive plant species.The aim of this study was to determine the allelopathic potential of invasive woody plant species occurringin Hungary. Juglone index of fourteen invasive woody plant species in Hungary was determined by themethod of Szabó (1997, comparing the effects of juglone and substance extracted of plant species withunknown allelopathic potential on the germination rate, shoot length and rooth length of white mustard(Sinapis alba L. used as receiver species. Results have proven a more or less expressed allelopathicpotential in case of all species. The juglone index at higher concentration extracts (5 g dry plant materialextracted with 100 ml distilled water of almost every studied species approaches to 1 or is above 1, thismeans the effect of the extracts is similar to juglone or surpasses it. In terms of juglone index, theallelopathic potential of false indigo (Amorpha fruticosa L., tree-of-heaven (Ailanthus altissima (Mill.Swingle and hackberry (Celtis occidentalis L. were the highest. Besides these species the treatment withthe extracts of black walnut (Juglans nigra L., black cherry (Prunus serotina Ehrh. and green ash(Fraxinus pennsylvanica MARSH. var. subintegerrima (Vahl Fern. reduced extremely significantly thegermination rate, shoot and root length, compared to the control.

  7. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

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    Wei Yang

    Full Text Available Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA-dependent pathway from an early stage upstream of NDR1 and EDS1.

  8. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

    Science.gov (United States)

    Yang, Wei; Xu, Xiaonan; Li, Yang; Wang, Yingzi; Li, Ming; Wang, Yong; Ding, Xinhua; Chu, Zhaohui

    2016-01-01

    Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA)-dependent pathway from an early stage upstream of NDR1 and EDS1.

  9. ALELOPATIA DO NIM NOS ASPECTOS FISIOLÓGICOS DA GERMINAÇÃO DE SEMENTES DE MARACUJÁ EM DISTINTOS PERÍODOS DE ARMAZENAMENTO

    Directory of Open Access Journals (Sweden)

    Naedja Nara de Araujo Neves

    2008-01-01

    Full Text Available The passion fruit tree (Passiflora edulis Sims f. flavicarpa Deg. is a fruitful tree whose the propagation usually is made for seeds. With the objective to study the possible effects allelopathy of neem in the physiologic aspects in germination of seeds of passion fruit in the different periods of storage. Was carried at UFERSA. For the acquisition of powder of neem, it was used plants located in institution. In the obtaining of seeds of passion fruits, it was used in natura fruits bought in the local supermarket; this seeds were extracted of fruits for fermentation. It was placed 50g of seeds of passion fruits together with each measure of powder of leaves of neem (0; 0,25; 0,50; 0,75; 1,0 g of powder of leaves of neem / 50 g of seeds of passion fruits. It was utilized the randomized design in esquire of portions subdivides, where the portions was composed of five dosages of powder of leaves neem.

  10. Allelopathic Effects of Aqueous Extract of Leaf Stem and Root of Sorghum bicolor on Seed Germination and Seedling Growth of Vigna radiata L.

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    Amir MOOSAVI

    2011-05-01

    Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants� growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.

  11. Isolation and Identification of Potential Allelochemicals from Aerial Parts of Avena fatua L. and Their Allelopathic Effect on Wheat.

    Science.gov (United States)

    Liu, Xingang; Tian, Fajun; Tian, Yingying; Wu, Yanbing; Dong, Fengshou; Xu, Jun; Zheng, Yongquan

    2016-05-11

    Five compounds (syringic acid, tricin, acacetin, syringoside, and diosmetin) were isolated from the aerial parts of wild oats (Avena fatua L.) using chromatography columns of silica gel and Sephadex LH-20. Their chemical structures were identified by means of electrospray ionization and high-resolution mass spectrometry as well as (1)H and (13)C nuclear magnetic resonance spectroscopic analyses. Bioassays showed that the five compounds had significant allelopathic effects on the germination and seedling growth of wheat (Triticum aestivum L.). The five compounds inhibited fresh wheat as well as the shoot and root growth of wheat by approximately 50% at a concentration of 100 mg/kg, except for tricin and syringoside for shoot growth. The results of activity testing indicated that the aerial parts of wild oats had strong allelopathic potential and could cause different degrees of influence on surrounding plants. Moreover, these compounds could be key allelochemicals in wild-oat-infested wheat fields and interfere with wheat growth via allelopathy. PMID:27079356

  12. Is growing buckwheat allelopathic?

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    Wirth, Judith

    2016-02-01

    Full Text Available The growth repressive effect of common buckwheat (Fagopyrum esculentum on redroot pigweed (Amaranthus retroflexus was studied by separating resource competition from root interactions between the two plant species in a pot trial in the phytotron. In order to verify this result in situ field trials were performed. A strong repression of redroot pigweed growth by buckwheat could be observed independently of shading. However, soil both from the field and phytotron trials in which buckwheat had been growing didn’t have an effect on redroot pigweed and lettuce (Lactuca sativa growth. Assuming that allelopathic compounds are present in the soil solution supplementary experiments were conducted. Lettuce root length was measured after exposing seeds to different “buckwheat soil” extracts. Moreover, buckwheat and lettuce developed at the same time next to each other in petri dishes. In none of the experiments an influence on lettuce and redroot pigweed development could be observed. We conclude that there are either no allelopathic molecules in the soil solution (not soluble in water or that they are rapidly degraded. The observed growth inhibiting effect seems to be due to a long term and constant exposure of small quantities of allelopathic molecules. However, it is also possible that growth repression of redroot pigweed by buckwheat is not due to allelopathy.

  13. Allelopathic interactions between Prorocentrum micans and Skeletonema costatum or Karenia mikimotoi in laboratory cultures

    Science.gov (United States)

    Ji, Xiaoqing; Han, Xiaotian; Zheng, Li; Yang, Baijuan; Yu, Zhiming; Zou, Jingzhong

    2011-07-01

    Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. micans and high densities of S. costatum inoculated into the same medium, the growth of P. micans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical(s). Last, a mathematical model was used to simulate growth and interactions between P. micans and S. costatum and between P. micans and K. mikimotoi in bi-algal cultures.

  14. Caffeine fostering of mycoparasitic fungi against phytopathogens.

    Science.gov (United States)

    Sugiyama, Akifumi; Sano, Cecile M; Yazaki, Kazufumi; Sano, Hiroshi

    2016-01-01

    Caffeine (1,3,7-trimethixanthine) is a typical purine alkaloid produced in more than 80 plant species. Its biological role is considered to strengthen plant's defense capabilities, directly as a toxicant to biotic attackers (allelopathy) and indirectly as an activator of defense system (priming). Caffeine is actively secreted into rhizosphere through primary root, and possibly affects the structure of microbe community nearby. The fungal community in coffee plant rhizosphere is enriched with particular species, including Trichoderma family, a mycoparasite that attacks and kills phytopathogens by coiling and destroying their hyphae. In the present study, the caffeine response of 8 filamentous fungi, 4 mycoparasitic Trichoderma, and 4 prey phytopathogens, was examined. Results showed that allelopathic effect of caffeine on fungal growth and development was differential, being stronger on pathogens than on Trichoderma species. Upon confronting, the prey immediately ceased the growth, whereas the predator continued to grow, indicating active mycoparasitism to have occurred. Caffeine enhanced mycoparasitism up to 1.7-fold. Caffeine thus functions in a double-track manner against fungal pathogens: first by direct suppression of growth and development, and second by assisting their natural enemy. These observations suggest that caffeine is a powerful weapon in the arms race between plants and pathogens by fostering enemy's enemy, and we propose the idea of "caffeine fostering" as the third role of caffeine. PMID:26529400

  15. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

    Science.gov (United States)

    Yang, Wei; Xu, Xiaonan; Li, Yang; Wang, Yingzi; Li, Ming; Wang, Yong; Ding, Xinhua; Chu, Zhaohui

    2016-01-01

    Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA)-dependent pathway from an early stage upstream of NDR1 and EDS1. PMID:26751786

  16. Investigating a Potential Auxin-Related Mode of Hormetic/Inhibitory Action of the Phytotoxin Parthenin.

    Science.gov (United States)

    Belz, Regina G

    2016-01-01

    Parthenin is a metabolite of Parthenium hysterophorus and is believed to contribute to the weed's invasiveness via allelopathy. Despite the potential of parthenin to suppress competitors, low doses stimulate plant growth. This biphasic action was hypothesized to be auxin-like and, therefore, an auxin-related mode of parthenin action was investigated using two approaches: joint action experiments with Lactuca sativa, and dose-response experiments with auxin/antiauxin-resistant Arabidopsis thaliana genotypes. The joint action approach comprised binary mixtures of subinhibitory doses of the auxin 3-indoleacetic acid (IAA) mixed with parthenin or one of three reference compounds [indole-3-butyric acid (IBA), 2,3,5-triiodobenzoic acid (TIBA), 2-(p-chlorophenoxy)-2-methylpropionic acid (PCIB)]. The reference compounds significantly interacted with IAA at all doses, but parthenin interacted only at low doses indicating that parthenin hormesis may be auxin-related, in contrast to its inhibitory action. The genetic approach investigated the response of four auxin/antiauxin-resistant mutants and a wildtype to parthenin or two reference compounds (IAA, PCIB). The responses of mutant plants to the reference compounds confirmed previous reports, but differed from the responses observed for parthenin. Parthenin stimulated and inhibited all mutants independent of resistance. This provided no indication for an auxin-related action of parthenin. Therefore, the hypothesis of an auxin-related inhibitory action of parthenin was rejected in two independent experimental approaches, while the hypothesis of an auxin-related stimulatory effect could not be rejected. PMID:26686984

  17. Screening Green Manure Cover Crops for their Allelopathic Effects on Some Important Weeds Found in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Runzika, M.

    2013-08-01

    Full Text Available Weed control is a serious problem in smallholder conservation agriculture farming areas in Zimbabwe. Green Manure Cover Crops (GMCCs, which improve soil fertility and reduce weeds through allelopathy, are likely to reduce the cost of weed control in these areas. A laboratory study was conducted at the University of Zimbabwe to investigate the effect of extracts of eleven GMCCs on the germination percentage, radicle and plumule length of Bidens pilosa, Eleusine indica and Pennisatum glaucum (pearl millet. A green house experiment was also done to determine the allelopathic potential of these GMCC extracts applied as soil incorporated residues on the emergence and dry matter production of E. indica, B. pilosa and Acanthospermum hispidum. GMCC extracts significantly reduced germination, radicle and plumule length of Pennisatum glaucum (P < 0.05 except for Crotalaria grahamiana and Raphanus sativas which had no effect on germination of Pearl millet. The emergence and dry matter of B. pilosa, E. indica and A. hispidum were significantly reduced by these legumes (P < 0.05 with the exception of common vetch (Vicia sativa which stimulated the emergence of A. hispidum. Most of the legumes that were used in this study have allelopathic effects on B. pilosa, E. indica and A. hispidum.

  18. Significance of investigating allelopathic interactions of marine organisms in the discovery and development of cytotoxic compounds.

    Science.gov (United States)

    Singh, Anshika; Thakur, Narsinh L

    2016-01-01

    Marine sessile organisms often inhabit rocky substrata, which are crowded by other sessile organisms. They acquire living space via growth interactions and/or by allelopathy. They are known to secrete toxic compounds having multiple roles. These compounds have been explored for their possible applications in cancer chemotherapy, because of their ability to kill rapidly dividing cells of competitor organisms. As compared to the therapeutic applications of these compounds, their possible ecological role in competition for space has received little attention. To select the potential candidate organisms for the isolation of lead cytotoxic molecules, it is important to understand their chemical ecology with special emphasis on their allelopathic interactions with their competitors. Knowledge of the ecological role of allelopathic compounds will contribute significantly to an understanding of their natural variability and help us to plan effective and sustainable wild harvests to obtain novel cytotoxic chemicals. This review highlights the significance of studying allelopathic interactions of marine invertebrates in the discovery of cytotoxic compounds, by selecting sponge as a model organism. PMID:26362501

  19. Continuous-release beads of natural allelochemicals for the long-term control of cyanobacterial growth: Preparation, release dynamics and inhibitory effects.

    Science.gov (United States)

    Huang, Haomin; Xiao, Xi; Lin, Fang; Grossart, Hans-Peter; Nie, Zeyu; Sun, Lijuan; Xu, Chen; Shi, Jiyan

    2016-05-15

    The effects of allelochemicals on cyanobacterial blooms have been observed for more than 20 years; however, the use of these compounds, usually involving a "direct-added" mode, has clear disadvantages, such as a short activity period or temporarily excessive localized concentration. Here, a simulated-allelopathy mode to facilitate the application of allelochemicals was proposed and tested on Microcystis aeruginosa. The continuous-release beads of 5,4'-dihydroxyflavone (DHF) were constitutive of a polymer matrix and showed a high drug-loading rate (47.18%) and encapsulation efficiency (67.65%) with a theoretical release time of approximately 120 d. Cyanobacterial growth tests showed that the DHF beads had long-term inhibition effects (>30 d), whereas those of "direct-added" DHF to cells lasted a maximum of 10 d. The beads also continuously affected the superoxide dismutase, catalase, and lipid peroxidation of M. aeruginosa. The inhibitory effects of DHF beads on cyanobacterial growth increased as initial cell densities of M. aeruginosa decreased, suggesting that the beads inhibit cyanobacterial activity more effectively in the early bloom phase. Consequently, the anti-cyanobacterial beads represent a novel application mode of allelochemicals with long-term inhibitory effects on cyanobacterial growth. Our study demonstrates that the successful application of allelochemicals offers great potential to control harmful cyanobacterial blooms, especially at the initial stage of development. PMID:26986500

  20. Zebrafish Embryo Toxicity Microscale Model for Ichthyotoxicity Evaluation of Marine Natural Products.

    Science.gov (United States)

    Bai, Hong; Kong, Wen-Wen; Shao, Chang-Lun; Li, Yun; Liu, Yun-Zhang; Liu, Min; Guan, Fei-Fei; Wang, Chang-Yun

    2016-04-01

    Marine organisms often protect themselves against their predators by chemical defensive strategy. The second metabolites isolated from marine organisms and their symbiotic microbes have been proven to play a vital role in marine chemical ecology, such as ichthyotoxicity, allelopathy, and antifouling. It is well known that the microscale models for marine chemoecology assessment are urgently needed for trace quantity of marine natural products. Zebrafish model has been widely used as a microscale model in the fields of environment ecological evaluation and drug safety evaluation, but seldom reported for marine chemoecology assessment. In this work, zebrafish embryo toxicity microscale model was established for ichthyotoxicity evaluation of marine natural products by using 24-well microplate based on zebrafish embryo. Ichthyotoxicity was evaluated by observation of multiple toxicological endpoints, including coagulation egg, death, abnormal heartbeat, no spontaneous movement, delayed hatch, and malformation of the different organs during zebrafish embryogenesis periods at 24, 48, and 72 h post-fertilization (hpf). 3,4-Dichloroaniline was used as the positive control for method validation. Subsequently, the established model was applied to test the ichthyotoxic activity of the compounds isolated from corals and their symbiotic microbes and to isolate the bioactive secondary metabolites from the gorgonian Subergorgia mollis under bioassay guidance. It was suggested that zebrafish embryo toxicity microscale model is suitable for bioassay-guided isolation and preliminary bioactivity screening of marine natural products. PMID:26838966

  1. Interspecific competition and allelopathic interaction between Karenia mikimotoi and Dunaliella salina in laboratory culture

    Science.gov (United States)

    He, Dong; Liu, Jiao; Hao, Qiang; Ran, Lihua; Zhou, Bin; Tang, Xuexi

    2016-03-01

    Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on diff erent temperature (15°C, 20°C, and 25°C) and lighting (40, 80, and 160 μmol/(m2·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-tocell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. mikimotoi were markedly influenced by both temperature ( P =0.013) and irradiance ( P =0.003), resulting in diff erent growth characteristics of D. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.

  2. Molecular and structural changes induced by essential oils treatments in Vicia faba roots detected by genotoxicity testing.

    Science.gov (United States)

    Sturchio, Elena; Boccia, Priscilla; Zanellato, Miriam; Meconi, Claudia; Donnarumma, Lucia; Mercurio, Giuseppe; Mecozzi, Mauro

    2016-01-01

    Over the last few years, there has been an increased interest in exploiting allelopathy in organic agriculture. The aim of this investigation was to examine the effects of essential oil mixtures in order to establish their allelopathic use in agriculture. Two mixtures of essential oils consisting respectively of tea tree oil (TTO) and clove plus rosemary (C + R) oils were tested. Phytotoxicity and genotoxicity tests on the root meristems of Vicia faba minor were performed. A phytotoxic influence was particularly relevant for C + R mixture, while genotoxicity tests revealed significant results with both C + R oil mixture and TTO. Phenotypic analysis on Vicia faba minor primary roots following C + R oil mixture treatment resulted in callose production, an early symptom attributed to lipid peroxidation. The approach described in this study, based on genotoxicity bioassays, might identify specific DNA damage induced by essential oil treatments. These tests may represent a powerful method to evaluate potential adverse effects of different mixtures of essential oils that might be useful in alternative agriculture. Future studies are focusing on the positive synergism of more complex mixtures of essential oils in order to reduce concentrations of potentially toxic components while at the same time maintaining efficacy in antimicrobial and antifungal management. PMID:26914511

  3. Isolation and Identification of Potential Allelochemicals from Aerial Parts of Avena fatua L. and Their Allelopathic Effect on Wheat.

    Science.gov (United States)

    Liu, Xingang; Tian, Fajun; Tian, Yingying; Wu, Yanbing; Dong, Fengshou; Xu, Jun; Zheng, Yongquan

    2016-05-11

    Five compounds (syringic acid, tricin, acacetin, syringoside, and diosmetin) were isolated from the aerial parts of wild oats (Avena fatua L.) using chromatography columns of silica gel and Sephadex LH-20. Their chemical structures were identified by means of electrospray ionization and high-resolution mass spectrometry as well as (1)H and (13)C nuclear magnetic resonance spectroscopic analyses. Bioassays showed that the five compounds had significant allelopathic effects on the germination and seedling growth of wheat (Triticum aestivum L.). The five compounds inhibited fresh wheat as well as the shoot and root growth of wheat by approximately 50% at a concentration of 100 mg/kg, except for tricin and syringoside for shoot growth. The results of activity testing indicated that the aerial parts of wild oats had strong allelopathic potential and could cause different degrees of influence on surrounding plants. Moreover, these compounds could be key allelochemicals in wild-oat-infested wheat fields and interfere with wheat growth via allelopathy.

  4. A Mixed-Culture Biofilm Model with Cross-Diffusion.

    Science.gov (United States)

    Rahman, Kazi A; Sudarsan, Rangarajan; Eberl, Hermann J

    2015-11-01

    We propose a deterministic continuum model for mixed-culture biofilms. A crucial aspect is that movement of one species is affected by the presence of the other. This leads to a degenerate cross-diffusion system that generalizes an earlier single-species biofilm model. Two derivations of this new model are given. One, like cellular automata biofilm models, starts from a discrete in space lattice differential equation where the spatial interaction is described by microscopic rules. The other one starts from the same continuous mass balances that are the basis of other deterministic biofilm models, but it gives up a simplifying assumption of these models that has recently been criticized as being too restrictive in terms of ecological structure. We show that both model derivations lead to the same PDE model, if corresponding closure assumptions are introduced. To investigate the role of cross-diffusion, we conduct numerical simulations of three biofilm systems: competition, allelopathy and a mixed system formed by an aerobic and an anaerobic species. In all cases, we find that accounting for cross-diffusion affects local distribution of biomass, but it does not affect overall lumped quantities such as the total amount of biomass in the system.

  5. Interactions between Ipomoea aquatica and Microbial Populations

    Institute of Scientific and Technical Information of China (English)

    Kan; Yuanqing; Sun; Ling; Zhang; Ying

    2014-01-01

    [Objective]This paper was to research the water purification mechanism of Ipomoea aquatica and its correlation with algae and rotifer. [Methods]Taking I. aquatica as the test material,Chlorella vulgaris,Scenedesmus obliquus,Microcystis aeroginosa and rotifer Adineta vaga with different densities were added to the hydroponics nutrients solutions of I. aquatica by the hydroponic ecological simulation method. The growth characteristics of I. aquatica,changes of microbial populations and the consumption status of nutrients in the nutritional solution were determined. And the interactions between the plant and the microbial populations were researched. [Results]When I. aquatica seedlings grew to a certain stage,growth of principal root stopped; while the lateral roots emerged greatly; and the nutrition absorption efficiency enhanced. As the inoculation concentration of C. vulgaris increased,root length of I. aquatica increased relatively great due to the competition for nutrients. The competition and allelopathy of M. aeroginosa and S. obliquus restricted the development of root system of I. aquatica. The grazing pressure of Chlorella vulgaris had little effects on M. aeroginosa,but restricted the rapid growth of S. obliquus. [Conclusions]This research provided data support for the application of fish-shrimp-vegetable aquaculture system.

  6. Transformation of toxic and allelopathic lantana into a benign organic fertilizer through vermicomposting

    Science.gov (United States)

    Hussain, Naseer; Abbasi, Tasneem; Abbasi, S. A.

    2016-06-01

    In a first study of its kind, the composition of vermicompost derived solely from the toxic and allelopathic weed lantana has been investigated using UV-visible and Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) and differential scanning calorimetry (DSC), gas chromatography-mass spectometry (GC-MS), and scanning electron microscopy (SEM). The studies reveal that a sharp reduction in humification index, substantial mineralization of organic matter and degradation of complex aromatics such as lignin and polyphenols into simpler carbohydrates and lipids occur in the course of vermicomposting. GC-MS analysis shows significant fragmentation, bio-oxidation and molecular rearrangements of chemical compounds in vermicompost in comparison to those in lantana. SEM micrographs of vermicompost reflect strong disaggregation of material compared to the much better formed lantana matrices. The phenols and sesquiterpene lactones which are specifically responsible for the toxicity and allelopathy of lantana are seen to get significantly degraded in the course of vermicomposting - turning it into a plant-friendly organic fertilizer. The study leads to the possibility that the millions of tons of phytomass that is generated annually by lantana can be gainfully utilized in producing organic fertilizer via vermicomposting.

  7. Allelopathic potential of oil seed crops in production of crops: a review.

    Science.gov (United States)

    Shah, Adnan Noor; Iqbal, Javaid; Ullah, Abid; Yang, Guozheng; Yousaf, Muhammad; Fahad, Shah; Tanveer, Mohsin; Hassan, Waseem; Tung, Shahbaz Atta; Wang, Leishan; Khan, Aziz; Wu, Yingying

    2016-08-01

    Agricultural production enhancement has been realized by more consumption of fossil energy such as fertilizer and agrochemicals. However, the production provides the present human with sufficient and diversified commodities, but at the same time, deprives in some extent the resources from the future human as well. In the other hand, it is known that synthetic herbicides face worldwide threats to human's health and environment as well. Therefore, it is a great challenge for agricultural sustainable development. The current review has been focussed on various oilseed crop species which launch efficient allelopathic intervention, either with weeds or other crops. Crop allelopathic properties can make one species more persistent to a native species. Therefore, these crops are potentially harmful to both naturalized as well as agricultural settings. On the other side, allelopathic crops provide strong potential for the development of cultivars that are more highly weed suppressive in managed settings. It is possible to utilize companion plants that have no deleterious effect on neighbor crops and can be included in intercropping system, thus, a mean of contributing to agricultural sustainable development. In mixed culture, replacement method, wherein differing densities of a neighbor species are planted, has been used to study phytotoxic/competitive effects. So, to use alternative ways for weed suppression has become very crucial. Allelochemicals have the ability to create eco-friendly products for weed management, which is beneficial for agricultural sustainable development. Our present study assessed the potential of four oilseed crops for allelopathy on other crops and associated weeds. PMID:27263104

  8. Study on Competition Characteristics of a Land Cover Crop Arachis pintoito Growth of Cocoa

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2006-12-01

    Full Text Available The existence of ground cover crop, such as Arachis pintoiin cocoa farm may enhance physical, chemistry and biological fertility of soil. Nevertheless, the presence of those cover crops potentially increase the competition with main crop in various means. The primary objective of this study was to investigate kinds of competition raised when cocoa plants cultivated with ground cover crop of A. pintoi. This study consisted of three experiments. The first experiment aimed to study possible allelopatic competition using root exudates solution of A. Pintoi as well as Leucaena leucocephalaand Adenanthera microsperma as check for being used for watering cocoa plants. The second experiment aimed to study the competition between A. pintoiand cocoa plants in field condition with 1 cover crop fully overlay ground surrounding cocoa basal trunk, 2 no cover crop overlay ground surrounding cocoa basal trunk in a distance of 40 cm in diameter, and 3 no cover crop as check. Third experiment aimed to study the competition between A. pintoiand cocoa plants in limited growth medium (pot, using 10 cm stolon shoots each 4, 2 and 0 shoots per pot. Results showed that A. Pintoidid not produce alleopatic exudates to restrict cocoa growth. Population of A. Pintoi had negative effect on cocoa plant growth in the field by reducing fresh trunk weight and dry root weight, even greater negative effect found in cocoa plant grown in limited growth medium by also reducing dry leaf and trunk weight and leaf area. Key words: Theobroma cacao, Arachis pintoi, allelopathy, competition, denantheramicrosperma, Leucaena leucocephala

  9. 供水及丁香酚对间作小麦蚕豆生长速率及籽粒产量的影响%Effect of Eugenol and Water Application on Crop Growth Rate and Grain Yield of Wheat Fava Bean Intercropping Systems

    Institute of Scientific and Technical Information of China (English)

    朱静; 柴强; 赵财; 刘辉娟; 周海燕

    2012-01-01

    In order to provide theoretical basis for the manual control regulation of intercropping system that existed allelochemicals, pot experiment was carried out to research the effect of eugenol on crop growth rate and grain yield of wheat faba/bean intercropping system at water application of 75%, 60% and 45% field capacity. The results showed that eugenol could inhibite the crop growth rate (CGR)of fava bean in the seedling-beginning flower and pod setting-mature period of faba bean, except sole faba bean with 75% water supply level and the intercropped faba bean with 60% water supply level, increased water supply can alleviate the inhitory action of eugenol on the sole faba bean, but the inhitory action of eugenol on the intercropped fava bean exacerbate, intercropping planting pattern can alleviate the inhitory action; eugenol could inhibite the wheat CGR after seedling period, increasing water supply can not alleviate the inhitory action of eugenol, intercropping planting pattern can alleviate the inhitory action of eugenol on the wheat CGR at the stage of flowering to maturity. Compared to weighted average sole grain yield, intercropped grain yield was increased by 24.92%~52.74% under the same water supply. Other treatments showed mat allelopathy has inhibitory effect on the grain yield of two crops except 45%water supply level. Intercropping planting pattern can alleviate the allelopathy of eugeno on the wheat, fava bean grain yield.%为了寻求人工调控存在化感物质间作群体的理论依据,通过盆栽试验,探讨不同供水水平下(田问持水量的75%、60%和45%),小麦根系分泌物丁香酚对单作和间作蚕豆、小麦生长速率(Crop Growth Rate,CGR)及籽粒产量的影响.结果表明:在蚕豆苗期-始花期、结荚-成熟期2个生育阶段,丁香酚对蚕豆生长速率整体表现为抑制作用,但结荚-成熟期75%供水水平下的单作、60%供水水平下的问作除外,增加供水缓解了单作蚕豆的

  10. Efeito de cascas de café e de arroz dispostas nas camadas do solo sobre a germinação e o crescimento inicial do caruru-de-mancha Allelopathic effect of coffee and rice husks arranged in soil layers on the germination and initial growth of Amaranthus viridis

    Directory of Open Access Journals (Sweden)

    J.C.F. Santos

    2001-08-01

    Full Text Available Estudos dos efeitos dos resíduos de plantas pela utilização de coberturas mortas no controle das plantas daninhas têm apresentado dificuldade de determinar a diferenciação entre alelopatia e competição. Atualmente, muitas pesquisas têm se referido a critérios que propõem evidência à alelopatia. Este trabalho em casa de vegetação visou determinar os efeitos alelopáticos proporcionados pelas cascas de café e de arroz sobre o caruru-de-mancha, por meio das disposições desses resíduos nas camadas do solo. O delineamento experimental foi o de blocos casualizados, com os tratamentos em quatro repetições e organizados num esquema fatorial (3x3, sendo cascas de café e de arroz e vermiculita expandida como um fator e suas disposições, com resíduos depositados no topo, incorporados na superfície e incorporados no fundo, como segundo fator. Como testemunha foi usado um tratamento adicional sem cobertura. De modo geral, resíduos de cascas proporcionaram inibição da germinação e estímulo ao crescimento do caruru-de-mancha. A casca de arroz proporcionou menor índice de velocidade de emergência e germinação de sementes do que a casca de café. A casca de café depositada no topo proporcionou maior crescimento e maior peso da matéria seca do caruru-de-mancha, seguido pela mesma casca incorporada na superfície do solo.Studies of plant residue effects involving mulches to control weeds in perennial crops are difficult to carry out due to the need to differentiate between allelopathy and competition. Many researches, nowadays, refer to criteria proving allelopathy. This work was established under greenhouse conditions to determine the allelopathic effects of coffee and rice husks on Amaranthus viridis through their arrangements in soil layers. The experimental design was a randomized block with four replications, arranged in a 3 x 3 factorial scheme, with coffee and rice husks and expanded vermiculite being one factor and

  11. Preliminary study on Allelpathy Effects of Mirabilis himalaca (Edgew.) Heim. seeds%喜马拉雅紫茉莉种子化感作用初探

    Institute of Scientific and Technical Information of China (English)

    辛福梅; 臧建成; 兰小中

    2012-01-01

      研究喜马拉雅紫茉莉种子水浸提液对绿豆、小麦种子萌发和幼苗生长的影响,分别用浓度为0.0125、0.025、0.05、0.1 g/ml的喜马拉雅紫茉莉种子水浸提液处理绿豆、小麦种子,测定其种子萌发及幼苗生长状况.结果表明,不同浓度的喜马拉雅紫茉莉种子水浸提液对绿豆和小麦种子萌发和幼苗生长均存在不同程度的抑制作用.其中,对绿豆发芽率的平均化感效应(RI)为-4.45,发芽势的为-7.23;对小麦发芽率的平均RI值为-8.05,发芽势的为-9.12;对绿豆苗高的平均RI值为-49.9,根长的为-71,根数的为-50;对小麦苗高的平均RI值为-34.7,根长的为-49.1,根数的为-52.7.可见,喜马拉雅紫茉莉种子水浸提液对不同作物的化感作用不同,对同一作物的不同发育时期化感作用也不同,对幼苗期的影响显著大于种子萌发期.%  This trial studied the impact of the seed germination and seeding growth of green beans and wheat on Aqueous Extracts of Mirabilis himalaca (Edgew.) seeds. With a concentration of 0.0125, 0.025, 0.05, 0.1g/Ml of aqueous extract dealed with mung bean and wheat seeds, seed germination and seedling growth conditions were determined. The results show that different concentrations of aqueous extracts of Mirabilis himalaca (Edgew.) Heim. seeds have different effect of restraining the seed germination and seedling growth of mung bean and wheat. Mung bean germination rate average RI value is-4.45, germination potential -7.23; wheat germina-tion rate average RI value is-8.05, germination potential-9.12;mung bean seedling height average RI value is -49.9, root length, -71, root number-50;average RI value is-34.7 wheat seedling height, root length to-49.1,root number-52.7. So, the allelopathy ef-fects of Mirabilis himalaca (Edgew.) seeds to different crop were different. The allelopathy effects of different developmental stages of the same crop are also different, the effects in the

  12. Research on Al elopathy between Different Kinds of Vegetables%不同蔬菜种类间化感作用研究

    Institute of Scientific and Technical Information of China (English)

    杨雨华; 宗建伟

    2014-01-01

    Allelopathy of water extracts of cucumber, pepper, tomato and Chinese cabbage was studied by pot plant. The results show that water extracts of cucumber, pepper, tomato and Chinese cabbage have autointoxication and water extract of cucumber restrains pepper and tomato seed germination and seedling growth as well as inhibits Chinese cabbage seedling root elongation; Water extract of pepper restrains cucumber seed germination and its root growth. With the treatment of pepper water immersion, tomato and Chinese cabbage seed germination and seedling growth are restrained. Water extract of tomato promotes the seedling growth of cucumber and Chinese cabbage, but restrains their root growth. After tomato water immersion treatment, seed germination rate, height of seedling, root length and fresh weight of pepper are lower compared with original ones. Water extract of Chinese cabbage restrains seed germination and seedling growth of cucumber, tomato and pepper. It is known by subordinate function value that the order of the allelopathy of various vegetables from strong to weak is Chinese cabbage> cucumber> pepper > tomato separately.%通过盆栽方式,研究了黄瓜、辣椒、番茄和白菜水浸液的化感作用。结果表明:黄瓜、辣椒、番茄和白菜水浸液均有自毒作用;黄瓜水浸液抑制辣椒、番茄的种子萌发和幼苗生长,抑制白菜幼苗根系的伸长;辣椒水浸液对黄瓜种子萌发和根系生长产生抑制作用,经辣椒水浸液处理过的番茄、白菜种子萌发和幼苗生长均受到抑制;番茄水浸液促进了黄瓜、白菜幼苗生长,却对2者根系生长表现出抑制作用,经番茄水浸液处理后的辣椒种子发芽率、苗高、根长和鲜重与对照相比,均有所降低;白菜水浸液抑制了黄瓜、辣椒、番茄3种作物的种子萌发和幼苗的生长。通过隶属函数值可知,不同蔬菜作物的化感作用从强到弱的顺序为:白菜>黄瓜>辣椒>番茄。

  13. 干旱胁迫与外源激素PDJ对不同基因型小麦化感潜力的诱导调控%Inducible regulation of allelopathic potential in different wheat genetypes under drought and prohydrojasmon (PDJ) treatment

    Institute of Scientific and Technical Information of China (English)

    支金虎; 马永清; 左胜鹏

    2009-01-01

    盆载条件下对4个不同基因型小麦品种于播种前以外源激素PDJ(10 mg·L~(-1))浸种处理和返青期始干旱胁迫,测定其光合特性、水分利用和化感抗草差异.结果表明:水分胁迫(田间持水量的45%)和PDJ处理均能增强几种供试小麦的化感抗草诱导效应,两者均通过降低杂草生物量从而抑制杂草生长.水分胁迫和PDJ处理均能增强"兰考95-25"、"小偃6号"拔节期的叶片光合速率,降低气孔限制值和提高水分利用率;"豫麦66"PDJ处理下可增强光合作用而降低水分利用率,但干旱胁迫下则相反;"兰考217"经PDJ处理光合速率和水分利用率均降低.典范对应分析发现供试小麦受到干旱胁迫和外源激素PDJ处理后会引起植物形态和光合生理的变化,从而影响其化感抗草特性.小麦整体化感潜势与以杂草生物量(杂草鲜重/盆)表示的抗草指标显著相关,而小麦的整体抗草特性主要与其水分利用率、光合速率和蒸腾速率显著正相关,与植物地上生物量、株高、节间距离和气孔导度显著负相关.%In a pot experiment, growth adaptation of four winter wheat (Triticum aestivum L.) accessions was investigated following seed pretreatment by soaking with prohydrojasmon (a kind of exogenous hormone at 10 mg · L~(-1)) before sowing. The seeds were subjected to artificial soil water regulation at 75% and 45% field capacity at the start of greening. Also in the experiment, the photosynthesis level, water use, variation of weed-controlling effect of allelopathy of wheat under acclimatized soil water and PDJ treatment was conducted. Soil drought and PDJ were used to stimulate the overall allelopathic inhibition and weed-resistance of wheat in the pot trial. The study shows that physiological response of "Lankao 95-25" and "Xiaoyan 6" to water shortage and PDJ is significant due to enhanced leaf net photosynthetic rate, water use efficiency and stoma capacity. Under PDJ

  14. Vermicomposting eliminates the toxicity of Lantana (Lantana camara) and turns it into a plant friendly organic fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, N.; Abbasi, Tasneem; Abbasi, S.A., E-mail: prof.s.a.abbasi@gmail.com

    2015-11-15

    Highlights: • It is shown for the first time that Lantana can lose its toxicity when vermicomposted. • The Lantana vermicompost is shown to be a good organic fertilizer. • FTIR studies identified Lantana’s toxic constituents destroyed by vermicomposting. • The findings have far-reaching implications in the gainful use of harmful weeds. - Abstract: In evidently the first study of its kind, vermicompost derived solely from a weed known to possess plant and animal toxicity was used to assess its impact on the germination and early growth of several plant species. No pre-composting or supplementation of animal manure was done to generate the vermicompost in order to ensure that the impact is clearly attributable to the weed. Whereas the weed used in this study, Lantana (Lantana camara), is known to possess strong negative allelopathy, besides plant/animal toxicity in other forms, its vermicompost was seen to be a good organic fertilizer as it increased germination success and encouraged growth of all the three botanical species explored by the authors – green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). In terms of several physical, chemical and biochemical attributes that were studied, the vermicompost appeared plant-friendly, giving best results in general when employed at concentrations of 1.5% in soil (w/w). Fourier transform infrared spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the allelopathic impact of Lantana were largely destroyed in the course of vermicomposting. There is also an indication that lignin content of Lantana was reduced during its vermicomposting. The findings open up the possibility that the billions of tons of phytomass that is generated annually by Lantana and other invasives can be gainfully utilized in generating organic fertilizer via vermicomposting.

  15. Effect of Different Concentrations of Garland Chrysanthemum Organ Water Extract on Seed Germination Characteristics of Watermelon%不同浓度茼蒿器官水浸提液对西瓜种子发芽特性的影响

    Institute of Scientific and Technical Information of China (English)

    范淑英; 肖旭峰; 熊春晖; 倪晓春; 吴才君

    2011-01-01

    采用0.001、0.01、0.1 g·mL-1的干茼蒿根、茎叶、花水浸提液处理西瓜种子,测定其发芽势、发芽率及胚根鲜质量,研究茼蒿水浸提液对西瓜种子的化感抑制率.结果表明:不同浓度茼蒿器官(根、茎叶、花)水浸提液对西瓜种子萌发有较强的抑制作用,随处理浓度升高,抑制作用越强,发芽势、发芽率、胚根鲜质量均低于对照,因此,茼蒿水浸提液浓度在0.001~0.1 g·mL-1对西瓜种子萌发存在明显的化感作用.%In order to study the effects of different concentrations of garland chrysanthemum organ water extract on seed germination characteristics of watermelon ( Citrullus lanatus ), 0.001, 0.01 and 0.1 g · mL-1 organ water extracts from garland chrysanthemum root, stem and leaf, flower were used to treat watermelon seeds and to test seed germination characteristics.The results showed that different concentrations of garland chrysanthemum root, stem and leaf, flower water extracts could inhibit seed germination of watermelon.The inhibitory effect increased along with the concentration rise.The germinability, germination percentage, radicle quality were all lower than the control.Therefore, 0.001-0.1 g · mL-1 garland chrysanthemum organ water extracts has distinct allelopathy effect on watermelon germination.

  16. Activity of Hydroxamic Acids from Secale cereale Against the Plant-Parasitic Nematodes Meloidogyne incognita and Xiphinema americanum.

    Science.gov (United States)

    Zasada, I A; Meyer, S L F; Halbrendt, J M; Rice, C

    2005-10-01

    ABSTRACT Cyclic hydroxamic acids are secondary metabolites found in the family Poaceae and have been implicated in the allelopathy of rye (Secale cereale). The toxicity of these compounds against plant-parasitic nematodes is unknown. DIBOA (2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one), DIMBOA (2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one), and their degradation products BOA (benzoxazolin-2(3H)-one) and MBOA (6-methoxy-benzoxazolin-2(3H)-one) were screened in vitro against Meloidogyne incognita second-stage juveniles (J2) and eggs and mixed-stages of Xiphinema americanum. Xiphinema americanum was more sensitive to DIBOA and DIMBOA than M. incognita J2, with a maximum apparent mortality of 96 and 92% compared to 73 and 72% at 90 mug/ml. Eggs of M. incognita were less sensitive to the hydroxamic acids than J2; only DIBOA resulted in a 50% reduction in egg hatch, with a lethal concentration (LC(50)) of 74 mug/ml compared to 21 mug/ml for J2. When M. incognita J2 were exposed to DIBOA for 48 h and the compound was removed and replaced with water, the LC(50) value increased from 21.0 to 40.7 mug/ml. MBOA was not toxic to X. americanum or M. incognita eggs, but was toxic to M. incognita J2, with LC(50) values of 44 and 20 mug/ml before and after the compound was removed and replaced with water. BOA was the least toxic hydroxamic acid tested; it did not reduce M. incognita egg hatch after 1 week of exposure or increase X. americanum mortality after 24 h of exposure. While in vitro studies provide a valuable starting point in determining the toxicity of the chemical component of rye, the relevance of the data to soil remains to be determined.

  17. Resource competition in plant invasions: emerging patterns and research needs

    Directory of Open Access Journals (Sweden)

    Margherita eGioria

    2014-09-01

    Full Text Available Invasions by alien plants provide a unique opportunity to examine competitive interactions among plants. While resource competition has long been regarded as a major mechanism responsible for successful invasions, given a well-known capacity for many invaders to become dominant and reduce plant diversity in the invaded communities, few studies have measured resource competition directly or have assessed its importance relatively to that of other mechanisms, at different stages of an invasion process. Here, we review evidence comparing the competitive ability of invasive species vs. that of co-occurring native plants, along a range of environmental gradients, showing that many invasive species have a superior competitive ability over native species, while invasive congeners are not necessarily competitively superior over native congeners, nor alien dominants are better competitors than native dominants. We discuss how the outcomes of competition depend on a number of factors, such as the heterogeneous distribution of resources, the stage of the invasion process, as well as phenotypic plasticity and evolutionary adaptation, which may result in increased or decreased competitive ability in both invasive and native species. Competitive advantages of invasive species over natives are often transient and only important at the early stages of an invasion process. It remains unclear how important resource competition is relative to other mechanisms (competition avoidance via phenological differences, niche differentiation in space associated with phylogenetic distance, recruitment and dispersal limitation, indirect competition, and allelopathy. We then identify the conceptual and methodological issues characterizing competition studies in plant invasions, and we discuss future research needs, including examinations of resource competition dynamics and of the impact of global environmental changes on competitive interactions between invasive and native

  18. Vermicomposting eliminates the toxicity of Lantana (Lantana camara) and turns it into a plant friendly organic fertilizer

    International Nuclear Information System (INIS)

    Highlights: • It is shown for the first time that Lantana can lose its toxicity when vermicomposted. • The Lantana vermicompost is shown to be a good organic fertilizer. • FTIR studies identified Lantana’s toxic constituents destroyed by vermicomposting. • The findings have far-reaching implications in the gainful use of harmful weeds. - Abstract: In evidently the first study of its kind, vermicompost derived solely from a weed known to possess plant and animal toxicity was used to assess its impact on the germination and early growth of several plant species. No pre-composting or supplementation of animal manure was done to generate the vermicompost in order to ensure that the impact is clearly attributable to the weed. Whereas the weed used in this study, Lantana (Lantana camara), is known to possess strong negative allelopathy, besides plant/animal toxicity in other forms, its vermicompost was seen to be a good organic fertilizer as it increased germination success and encouraged growth of all the three botanical species explored by the authors – green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). In terms of several physical, chemical and biochemical attributes that were studied, the vermicompost appeared plant-friendly, giving best results in general when employed at concentrations of 1.5% in soil (w/w). Fourier transform infrared spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the allelopathic impact of Lantana were largely destroyed in the course of vermicomposting. There is also an indication that lignin content of Lantana was reduced during its vermicomposting. The findings open up the possibility that the billions of tons of phytomass that is generated annually by Lantana and other invasives can be gainfully utilized in generating organic fertilizer via vermicomposting

  19. Effects of climate warming on plant autotoxicity in forest evolution: a case simulation analysis for Picea schrenkiana regeneration.

    Science.gov (United States)

    Ruan, Xiao; Pan, Cun-De; Liu, Run; Li, Zhao-Hui; Li, Shu-Ling; Jiang, De-An; Zhang, Jing-Chi; Wang, Geoff; Zhao, Yin-Xian; Wang, Qiang

    2016-08-01

    In order to explore how plant autotoxicity changes with climate warming, the autotoxicity of P. schrenkiana needles' water extract, organic extract fractions, and key allelochemical DHAP was systemically investigated at the temperature rising 2 and 4°C based on the data-monitored soil temperature during the last decade in the stage of Schrenk spruce regeneration (seed germination and seedling growth). The results showed that the criterion day and night temperatures were 12°C and 4°C for seed germination, and 14°C and 6°C for seedling growth, respectively. In the presence of water extract, the temperature rise of 2°C significantly inhibited the germination vigor and rate of P. Schrenkiana seed, and a temperature rise of 4°C significantly increased the inhibition to the seedling growth (P < 0.05). Among the three organic fractions, the low-polar fraction showed to be more phytotoxic than the other two fractions, causing significant inhibitory effects on the seed germination and growth even at low concentration of 0.1 mg/mL, and the inhibition effect was enhanced as temperature increased. The temperature rise significantly enhanced the promotion effect of DHAP, while the inhibition effect of temperature rise became less important with increasing concentration of DHAP. This investigation revealed that autotoxicity of P. schrenkiana was affected by the climate warming. As expected, it provided an insight into the mechanism and effectiveness of allelopathy in bridging the causal relationship between forest evolution and climate warming.

  20. Phytomedical investigation of Najas minor All. in the view of the chemical constituents.

    Science.gov (United States)

    Topuzovic, Marina D; Radojevic, Ivana D; Dekic, Milan S; Radulovic, Niko S; Vasic, Sava M; Comic, Ljiljana R; Licina, Braho Z

    2015-01-01

    Plants are an abundant natural source of effective antibiotic compounds. Phytomedical investigations of certain plants haven't still been conducted. One of them is Najas minor (N. minor), an aquatic plant with confirmed allelopathy. Research conducted in this study showed the influence of water and ethyl acetate extracts of N. minor on microorganisms, in the view of chemical profiling of volatile constituents and the concentrations of total phenols, flavonoids and tannins. Antimicrobial activity was defined by determining minimum inhibitory and minimum microbicidal concentrations using microdilution method. Influence on bacterial biofilm formation was performed by tissue culture plate method. The total phenolics, flavonoids and condensed tannins were determined by Folin-Ciocalteu, aluminum chloride and butanol-HCl colorimetric methods. Chemical profiling of volatile constituents was investigated by GC and GC-MS. Water extract didn't have antimicrobial activity below 5000 µg/mL. Ethyl acetate extract has shown strong antimicrobial activity on G+ bacteria - Staphylococcus aureus PMFKGB12 and Bacillus subtilis (MIC antibiofilm activity was obtained on Escherichia coli ATCC25922 (BIC50 at 719 µg/mL). Water extract had higher yield. Ethyl acetate extract had a significantly greater amount of total phenolics, flavonoids and tannins. As major constituent hexahydrofarnesyl acetone was identified. The ethyl acetate extract effected only G+ bacteria, but the biofilm formation of G-bacteria was suppressed. There was a connection between those in vivo and in vitro effects against pathogenic bacterial biofilm formation. All of this points to a so far unexplored potential of N. minor. PMID:26535038

  1. Arbuscular mycorrhizal fungi facilitate the invasion of Solidago canadensis L. in southeastern China

    Science.gov (United States)

    Yang, Ruyi; Zhou, Gang; Zan, Shuting; Guo, Fuyu; Su, Nannan; Li, Jing

    2014-11-01

    The significance of arbuscular mycorrhizal fungi (AMF) in the process of plant invasion is still poorly understood. We hypothesize that invasive plants would change local AMF community structure in a way that would benefit themselves but confer less advantages to native plants, thus influencing the extent of plant interactions. An AMF spore community composed of five morphospecies of Glomus with equal density (initial AMF spore community, I-AMF) was constructed to test this hypothesis. The results showed that the invasive species, Solidago canadensis, significantly increased the relative abundance of G. geosperum and G. etunicatum (altered AMF spore community, A-AMF) compared to G. mosseae, which was a dominant morphospecies in the monoculture of native Kummerowia striata. The shift in AMF spore community composition driven by S. canadensis generated functional variation between I-AMF and A-AMF communities. For example, I-AMF increased biomass and nutrient uptake of K. striata in both monocultures and mixtures of K. striata and S. canadensis compared to A-AMF. In contrast, A-AMF significantly enhanced root nitrogen (N) acquisition of S. canadensis grown in mixture. Moreover, mycorrhizal-mediated 15N uptake provided direct evidence that I-AMF and A-AMF differed in their affinities with native and invading species. The non-significant effect of A-AMF on K. striata did not result from allelopathy as root exudates of S. canadensis exhibited positive effects on seed germination and biomass of K. striata under naturally occurring concentrations. When considered together, we found that A-AMF facilitated the invasion of S. canadensis through decreasing competitiveness of the native plant K. striata. The results supported our hypothesis and can be used to improve our understanding of an ecosystem-based perspective towards exotic plant invasion.

  2. Complex effects of fertilization on plant and herbivore performance in the presence of a plant competitor and activated carbon.

    Directory of Open Access Journals (Sweden)

    Nafiseh Mahdavi-Arab

    Full Text Available Plant-herbivore interactions are influenced by host plant quality which in turn is affected by plant growth conditions. Competition is the major biotic and nutrient availability a major abiotic component of a plant's growth environment. Yet, surprisingly few studies have investigated impacts of competition and nutrient availability on herbivore performance and reciprocal herbivore effects on plants. We studied growth of the specialist aphid, Macrosiphoniella tanacetaria, and its host plant tansy, Tanacetum vulgare, under experimental addition of inorganic and organic fertilizer crossed with competition by goldenrod, Solidago canadensis. Because of evidence that competition by goldenrod is mediated by allelopathic compounds, we also added a treatment with activated carbon. Results showed that fertilization increased, and competition with goldenrod decreased, plant biomass, but this was likely mediated by resource competition. There was no evidence from the activated carbon treatment that allelopathy played a role which instead had a fertilizing effect. Aphid performance increased with higher plant biomass and depended on plant growth conditions, with fertilization and AC increasing, and plant competition decreasing aphid numbers. Feedbacks of aphids on plant performance interacted with plant growth conditions in complex ways depending on the relative magnitude of the effects on plant biomass and aphid numbers. In the basic fertilization treatment, tansy plants profited from increased nutrient availability by accumulating more biomass than they lost due to an increased number of aphids under fertilization. When adding additional fertilizer, aphid numbers increased so high that tansy plants suffered and showed reduced biomass compared with controls without aphids. Thus, the ecological cost of an infestation with aphids depends on the balance of effects of growth conditions on plant and herbivore performance. These results emphasize the importance

  3. Complex effects of fertilization on plant and herbivore performance in the presence of a plant competitor and activated carbon.

    Science.gov (United States)

    Mahdavi-Arab, Nafiseh; Meyer, Sebastian T; Mehrparvar, Mohsen; Weisser, Wolfgang W

    2014-01-01

    Plant-herbivore interactions are influenced by host plant quality which in turn is affected by plant growth conditions. Competition is the major biotic and nutrient availability a major abiotic component of a plant's growth environment. Yet, surprisingly few studies have investigated impacts of competition and nutrient availability on herbivore performance and reciprocal herbivore effects on plants. We studied growth of the specialist aphid, Macrosiphoniella tanacetaria, and its host plant tansy, Tanacetum vulgare, under experimental addition of inorganic and organic fertilizer crossed with competition by goldenrod, Solidago canadensis. Because of evidence that competition by goldenrod is mediated by allelopathic compounds, we also added a treatment with activated carbon. Results showed that fertilization increased, and competition with goldenrod decreased, plant biomass, but this was likely mediated by resource competition. There was no evidence from the activated carbon treatment that allelopathy played a role which instead had a fertilizing effect. Aphid performance increased with higher plant biomass and depended on plant growth conditions, with fertilization and AC increasing, and plant competition decreasing aphid numbers. Feedbacks of aphids on plant performance interacted with plant growth conditions in complex ways depending on the relative magnitude of the effects on plant biomass and aphid numbers. In the basic fertilization treatment, tansy plants profited from increased nutrient availability by accumulating more biomass than they lost due to an increased number of aphids under fertilization. When adding additional fertilizer, aphid numbers increased so high that tansy plants suffered and showed reduced biomass compared with controls without aphids. Thus, the ecological cost of an infestation with aphids depends on the balance of effects of growth conditions on plant and herbivore performance. These results emphasize the importance to investigate both

  4. Establishment and persistence of common ragweed (Ambrosia artemisiifolia L.) in disturbed soil as a function of an urban-rural macro-enviornment.

    Energy Technology Data Exchange (ETDEWEB)

    Lewis H. Ziska, Kate George, David A. Frenz

    2007-01-01

    No data are available on whether rising carbon dioxide concentration [CO2] or increased air temperature can alter the establishment and persistence of common ragweed (Ambrosia artemisiifolia L.) within a plant community following soil disturbance. To determine ragweed longevity, we exposed disturbed soil with a common seed bank population to an in situ temperature and [CO2] gradient along an urban-rural transect beginning in early 2002. No other consistent differences in meteorological variables (e.g. wind speed, humidity, PAR, tropospheric ozone) as a function of urbanization were documented over the course of the study (2002-2005). Above-ground measurements of biomass over this period demonstrated that ragweed along the transect responded to urban induced increases in [CO2]/temperature with peak biomass being observed at this location by the end of 2003. However, by the Fall of 2004, and continuing through 2005, urban ragweed populations had dwindled to a few plants. The temporal decline in ragweed populations was not associated with increased disease, herbivory or auto-allelopathy, but was part of a demographic reduction in the total number of annual plant species observed for the urban location. In a separate experiment, we showed that such a demographic shift is consistent with CO2/temperature induced increases in biomass and litter accumulation, with a subsequent reduction in germination / survival of annual plant species. Overall, these data indicate that [CO2]/temperature differences associated with urbanization may increase initial ragweed productivity and pollen production, but suggest that long-term, multi-year persistence of ragweed in the urban macro-environment may be dependent on other factors.

  5. Changes in gametophyte physiology of Pteris multifida induced by the leaf leachate treatment of the invasive Bidens pilosa.

    Science.gov (United States)

    Zhang, Kai-Mei; Shen, Yu; Fang, Yan-Ming; Liu, Ying

    2016-02-01

    In recent years, the response of fern gametophytes to environment has raised much attention. However, studies on the influence of plant invasion to fern gametophytes are scarce. Allelopathy plays an important role in biological invasion. Hence, it is necessary to study the allelopathic effects of invasive plants on fern gametophytes and elucidate the mechanisms by which invasive plants cause phytotoxicity. As one of the main invasive plants in China, Bidens pilosa exhibits allelopathic effects on spermatophyte growth. Field investigation shows that many ferns are threatened by the invasion of B. pilosa. The distribution of Pteris multifida overlaps with that of B. pilosa in China. To examine the potential involvement of allelopathic mechanisms of B. pilosa leaves, changes in the physiology in P. multifida gametophytes are analyzed. We found that cell membrane and antioxidant enzyme activities as well as photosynthesis pigment contents of the gametophytes were affected by B. pilosa leachates. Gametophytes of P. multifida exposed to B. pilosa had increased damages to cell membranes, expressed in thiobarbituric acid reacting substance (TBARS) concentrations, malondialdehyde (MDA), electrolyte leakage (membrane permeability), and degree of injury. Enzyme activities, assessed by superoxide dismutase (SOD) and catalase (CAT) as well as guaiacol peroxidase (GPX) enhanced with the increase in leachate concentration after 2-day exposure. Meanwhile, lower chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car), and the total chlorophyll were measured as leachate concentrations increased. At day 10, leaf leachates of B. pilosa exhibited the greatest inhibition. These results suggest that the observed inhibitory or stimulatory effects on the physiology studied can have an adverse effect on P. multifida and that allelopathic interference seems to have involved in this process. PMID:26490937

  6. Allelopathic potential and ecotoxicity evaluation of gallic and nonanoic acids to prevent cyanobacterial growth in lentic systems: A preliminary mesocosm study.

    Science.gov (United States)

    Techer, Didier; Fontaine, Pascal; Personne, Aline; Viot, Sandrine; Thomas, Marielle

    2016-03-15

    as small freshwater ponds may help to design innovative allelopathy-based aquatic ecotechnologies. PMID:26780141

  7. 黄瓜枯萎病生物防治策略研究进展%Research Progress in Biological Control Strategies for Fusarium Wilt of Cucumber

    Institute of Scientific and Technical Information of China (English)

    蒲子婧; 张艳菊; 刘东; 代丽婷; 王文博

    2011-01-01

    黄瓜枯萎病是黄瓜栽培过程中经常发生的一种土传性病害,给农业生产造成了严重损失.近年来,利用生物方法防治黄瓜枯萎病取得了较大进展,并呈现多样化的发展趋势,已成为防治该病害的重要且有效手段.本文从利用拮抗微生物和植物化感作用两方面对国内外黄瓜枯萎病生物防治的主要手段进行了总结,概述了各种生防因子的作用机制及主要研究成果,并提出应综合考虑当地实际情况,利用植物化感作用及生防作用物自身特点,因地制宜地制定黄瓜枯萎病生物防治策略.%Fusarium wilt is a common disease in cucumber ( Cucumis sativus L. ) culture, which has brought severe loss to agriculture production. In recent years, great progress has been made in controlling this disease by biological control method and a diversified development trend is presented. Bio-control has become an important and effective mean against fusarium wilt in cucumber. This study summarizes the bio-control method for cucumber fusarium wilt both in China and abroad from two aspects of utilizing antagonistic microorganisms and plant allelopathy. It also briefly introduces the functional mechanism of various bio-control factors and the main research achievements, and puts forward suggestions of taking comprehensive consideration according to local condition and developing bio-control strategy to tackle with cucumber fusarium wilt.

  8. Gene expression patterns of the coral Acropora millepora in response to contact with macroalgae

    Science.gov (United States)

    Shearer, T. L.; Rasher, D. B.; Snell, T. W.; Hay, M. E.

    2012-12-01

    Contact with macroalgae often causes coral mortality, but the roles of abrasion versus shading versus allelopathy in these interactions are rarely clear, and effects on gene expression are unknown. Identification of gene expression changes within corals in response to contact with macroalgae can provide insight into the mode of action of allelochemicals, as well as reveal transcriptional strategies of the coral that mitigate damage from this competitive interaction, enabling the coral to survive. Gene expression responses of the coral Acropora millepora after long-term (20 days) direct contact with macroalgae ( Chlorodesmis fastigiata, Dictyota bartayresiana, Galaxaura filamentosa, and Turbinaria conoides) and short-term (1 and 24 h) exposure to C. fastigiata thalli and their hydrophobic extract were assessed. After 20 days of exposure, T. conoides thalli elicited no significant change in visual bleaching or zooxanthellae PSII quantum yield within A. millepora nubbins, but stimulated the greatest alteration in gene expression of all treatments. Chlorodesmis fastigiata, D. bartayresiana, and G. filamentosa caused significant visual bleaching of coral nubbins and reduced the PSII quantum yield of associated zooxanthellae after 20 days, but elicited fewer changes in gene expression relative to T. conoides at day 20. To evaluate initial molecular processes leading to reduction of zooxanthella PSII quantum yield, visual bleaching, and coral death, short-term exposures to C. fastigiata thalli and hydrophobic extracts were conducted; these interactions revealed protein degradation and significant changes in catalytic and metabolic activity within 24 h of contact. These molecular responses are consistent with the hypothesis that allelopathic interactions lead to alteration of signal transduction and an imbalance between reactive oxidant species production and antioxidant capabilities within the coral holobiont. This oxidative imbalance results in rapid protein degradation

  9. Measurement of monoterpene hydrocarbon levels in vapor phase surrounding single-leaf pinyon (Pinus monophylla Torr. & Frem.: Pinaceae) understory litter.

    Science.gov (United States)

    Wilt, F M; Miller, G C; Everett, R L

    1993-07-01

    A headspace air-sampling experiment was performed in the laboratory to determine the identity and concentrations of monoterpene hydrocarbons that could be attained in the vapor phase surrounding single-leaf pinyon pine (Pinus monophylla Torr. & Frem.) understory litter using controlled air collection conditions at a simulated field temperature of 37.8°C. The total monoterpene hydrocarbon content in 21 sequential samples of air collected from a sealed glass carboy packed with 1.44 kg of single-leaf pinyon litter equivalent to a bulk density of 0.15 g/cm(3) averaged 3.56 ± 1.04 mg/liter. The monoterpenesα-pinene and camphene were present in the vapor phase at the highest concentrations, averaging 2.40±0.64 and 0.68±0.22 mg/ liter, respectively. Myrcene,β-pinene, 3-carene,β-phellandrene, andγ-terpinene were all present at average concentrations below 0.30 mg/liter. The first two traps of the sequential air samples yielded the highest concentrations for the monoterpene hydrocarbons; however, the average total levels were relatively stable throughout the remaining 19 traps. Therefore, the data indicate that these hydrocarbons volatilize from the source pinyon litter and maintain an equilibrium in the vapor phase. Although this analysis was conducted using an artificial system, combined with results from our previous studies, mounting evidence indicates that monoterpene hydrocarbons present in the vapor phase of the single-leaf pinyon understory may be toxic to a variety of native plant species and thus further implicates allelopathy as a significant contributor to the observed patterning of associated vegetation in these forests. PMID:24249172

  10. 核桃叶腐解液对小麦幼苗生理指标的影响%Effect of Decomposition Liquids from the Leaves of Juglans regia on Physiological Indexes of Seedlings of Wheat

    Institute of Scientific and Technical Information of China (English)

    马世荣; 王东; 张博

    2013-01-01

      In order to explore the allelopathy effect of decomposition liquids from the leaves of Juglans regia on wheat ,the effects of the decomposition liquids on germination rate ,amylase activity ,Pro content ,α‐NA content and MDA content of seedlings of four wheat varieties (lines)were studied .The results showed that the decom‐position liquids from the leaves of Juglans regia could significantly reduce or decrease the germination rate , amylase activity and α‐NA content ,significantly increase the Pro and MDA content ,and its effects increased with the increasing of extract concentration .The results also showed that four wheat varieties (lines)seeds had different tolerability .%  为揭示核桃叶腐解液对小麦的化感效应,选用4个小麦品种(系)的种子为受体,研究了不同浓度核桃叶腐解液对小麦种子萌发率、幼苗淀粉酶活力、脯氨酸含量、α‐NA含量和MDA含量的影响。结果表明:核桃叶腐解液可显著降低4个小麦品种(系)种子的萌发率、淀粉酶活性和a‐NA含量,显著提高Pro含量和MDA含量,且这些变化均具有明显的浓度依赖性。结果还表明4个小麦品种(系)对核桃叶腐解液表现出不同程度的耐受性。

  11. 植物体中萜类物质化感作用的研究进展%Advances of research on allelopathic potencial of terpenoids in plants

    Institute of Scientific and Technical Information of China (English)

    张秋菊; 张爱华; 孙晶波; 张连学

    2012-01-01

    Terpenoids widely exist in higher plants as volatile oil, especially in Compositae family. They have the largest variety of plant secondary metabolization products and are classified into monoterpene, diterpene, sesquiterpene, triterpene and polyterpene according to their structures. Terpenoids are one of the main types of allelochemicals, of which monoterpene and sesquiterpene have stronger bioactivities. The synthesized terpenids are mainly released from plants into soil through volatilization or root exudation and disturb the growth and development of neighboring plants and selfish. Currently, the allelopathy on terpenoids had received increased attention in plant ecology field in China and abroad. This paper made a systematic discussion on the distribution of trpenoids, accumulation characteristic, releasing pathways in plants and its impact factors, etc. And it analyzed the allelopathic mechanism of trpenoids and summarized the research progress in this area in recent years. The paper considered that the trpenoids played a special role on allelopathic activity and exhibited a stronger inhibitory even though the concentration was lower. The complicated allelopathy of terpenoids may be due to their wide varieties. Moreover, many factors all influenced the releasing of terpenoids. Finally, the paper pointed out some key problems in current researches and also made a prospect for the research trends in the future on the allelopathy of terpenoids. It is suggested that further study should be focused on the collecting method of terpenoid allelochemicals and the influences of transformed medium such as soil or air on allelopathic activity. In addition, it is effective and feasible to study allelopathic mechanism of terpenoids through the solution of discipline-crossing.%萜类物质主要以挥发油的形式广泛存在于高等植物中,尤以菊科植物含量丰富.萜类是天然物质中种类最多的一类,按结构可分为单萜、双萜、倍半萜、三

  12. 土荆芥挥发油对豌豆根边缘细胞的诱导和胁迫作用%Induced and stress effects of volatile oil from Chenopodium ambrosioide L. on root border cells of pea

    Institute of Scientific and Technical Information of China (English)

    何兵; 汪利沙; 王亚男; 张红; 李群; 马丹炜

    2013-01-01

      为探讨化感胁迫对根边缘细胞的诱导效应,实验采用悬空气培养法培养豌豆(Pisum sativum L.)露白种子,在保留根边缘细胞和去除根边缘细胞状态下,选取相对根长、根边缘细胞数量及死亡率、果胶甲基酯酶(PME)等指标研究了豌豆根边缘细胞对不同剂量土荆芥挥发油化感作用的响应。结果表明:1)与对照相比,随着挥发油处理剂量增加,根的伸长被显著抑制(P<0.05)。2)每个处理时间内,随着土荆芥挥发油剂量增加,根边缘细胞数量整体表现出先增加后减少的趋势,在低剂量2μL处理中达极大值。3)土荆芥挥发油诱导豌豆根边缘细胞死亡,随着处理时间的延长和处理剂量的增加,这种毒害效应程度加剧,除去边缘细胞实验组中10μL挥发油处理24 h时,根边缘细胞死亡率达到100%。在较低剂量挥发油作用下,保留根边缘细胞组的根边缘细胞死亡率高于去除根边缘细胞组,而在高剂量挥发油处理情况则相反。4)在同一处理时间,随挥发油剂量增加,各处理组PME活性持续升高,去处边缘细胞组处理24 h后不同剂量处理皆显著高于对照,而根边缘细胞数量总体表现先增加后减少。综合以上结果,保留根边缘细胞的根尖根边缘细胞的数量减少量较少,说明根边缘细胞能缓解土荆芥挥发油的化感胁迫;去除根边缘细胞组的PME活性升高较多,表明土荆芥化感胁迫诱导了根边缘细胞的产生。%The aim of this study was to investigate the inductive effect of root border cells (RBCs) of pea (Pisum sativum L.) under allelopathy related stress. Aeroponic method was used to cultivate the germinated pea seeds. Two types of samples were prepared, normal seed (control) and ones without root border cell (experimental group). Physiological indices, including relative root length, the number and mortality of RBCs, as well

  13. Molecular Identification of the Fungi in the Rhizospheric Soil of Soybean%大豆根际土壤真菌分子生物学鉴定方法

    Institute of Scientific and Technical Information of China (English)

    接伟光; 张勇; 蔡柏岩; 白莉; 王丽阳; 李二平

    2011-01-01

    The fungi in the rhizospheric soil of soybean played a vital role in the formation of soil fertility, the spread of soilborne diseases, the occurrence of allelopathy, etc. In particularly, soybean root rot caused by soil fungi has became a major disease which result in soybean production declined dramatically in China. Therefore, the rapid identification of the fungi in rhizospheric soil of soybean has great significance in preventing and curing fungal diseases of soybean. In this study, the fungal spores were isolated from soybean rhizospheres following a procedure including wet sieving, decanting, and separation in a sucrose gradient. Nested-PCR was conducted to specifically amplify the large-subunit (28S) rDNA D1/D2 domain sequences. They were identified from sequencing, and phylogenetic analysis. It showed that sequence alignment of the DT-1 28S rDNA D1/D2 domain sequence to fungi sequences in the database revealed that DT-1 shared 97% homology with the corresponding DT-1 sequence; DT-2 clusters shared 99% homology with the corresponding Mucor racemosus(Y213713) sequence. Results demonstrate that the method can get results quickly and accurately, and is suitable for identification of fungi in rhizospheric soil of soybean.%以大豆根际土壤为研究对象,采用湿筛倾析-蔗糖离心法分离大豆根际土壤真菌孢子.应用Nested-PCR技术扩增其28S rDNA D1/D2区域,并结合DNA测序、系统发育分析,对其进行分类鉴定.结果表明:筛选出的大豆根际土壤真菌孢子DT-1与土壤真菌(AB438763)有较高的序列同源性,为97%;DT-2与Mucor racemosus (Y213713)有较高的序列同源性,为99%.此方法适用于大豆根际土壤真菌的鉴定,并且能够快速准确地得到试验结果.

  14. Cover crop management in the weed control and productive performance in cornManejo de plantas de cobertura no controle de plantas daninhas e desempenho produtivo da cultura do milho

    Directory of Open Access Journals (Sweden)

    Pedro Valério Dutra de Moraes

    2013-05-01

    Full Text Available Objetivou-se avaliar espécies vegetais com potencial alelopático, associados às práticas de manejo e ao uso de herbicida nicosulfuron, no controle de plantas daninhas e nos componentes de produtividade da cultura do milho. O delineamento experimental utilizado foi em blocos ao acaso, com quatro repetições. O experimento foi composto por três fatores: espécies de cobertura, manejo das coberturas e aplicação ou não de herbicida nicosulfuron em pós-emergência. As variáveis avaliadas foram: número de plantas daninhas, número de fileiras de grãos, número de grãos por fileira, número de grãos por espiga e produtividade de grãos de milho. A cobertura de azevém, em geral, reduz o número de plantas daninhas emergidas e favorece o desempenho produtivo do milho. O manejo das plantas de cobertura com roçada e retirada da palha reduz a produtividade do milho. A maior produtividade do milho, foi observada com a aplicação de nicosulfuron em pós-emergência, independente da cultura de cobertura ou do manejo adotado. The objective of the study was evaluate the allelopathy of cover species, associated to management practices and use of nicosulfuron herbicide on the productive performance of corn. The experimental design consisted of complete randomized block with four replications. The treatments were: cover species, cover management and application or not of post-emergence herbicide. The variables evaluated were: number of weeds, number of rows kernels, number of kernels rows, number of kernels ear and grain yield of corn. Lolium multiflorum, reduced the number of emerged weeds and provides the best results in productive performance. The management simulated grazing, does not favor the yield of corn. The application of nicosulfuron in post-emergence, along with the allelopathic activity increases the productive performance of corn, regardless of cover crop or soil management.

  15. 旱地农业区危害大豆的鸟类及保护性预防%Birds Harm to Soybean in Dryland Agricultural Areas and Protective Prevention

    Institute of Scientific and Technical Information of China (English)

    降云峰; 刘学义

    2013-01-01

    With the improvement of living environment,the number of birds associated with soybean production in the northern China have been restored.As a member of the food chain,birds have close allelopathy relationship with soybean.Soybean seedlings are threatened by some birds of Columbidae and Phasianidae families in dry land area,which often results in soybean seedlings deficiency.These birds include rock pigeon,rock dove,gray turtledove,powder head turtledove,chukar,big chukar,pheasant and quail,most of them are national protected animals,hunting is strictly prohibited.Protective control measures based on the characteristics of these birds hazards soybean has proposed.Including(i) choose varieties with strong drought resistance,small grain,green cotyledon,and purple flower,so as to circumvent the hazard of birds;(ii) adopt cultivation techniques with fast centralized emergence targets to reduce bird hazards ; (iii) adopt bird repellents and apparatus measures to keep away the pest birds.%随着我国鸟类生存环境的改善,北方地区与大豆生产相关的鸟类数量得到恢复.鸟类与大豆具有十分密切的相生相克关系,是自然生态环境中食物链之一.旱地大豆苗期主要受鸠鸽科和雉科中部分鸟类威胁,常常导致大豆缺苗断垄或毁苗情况出现.这些鸟类包括岩鸽、原鸽、灰斑鸠、粉头斑鸠、石鸡、大石鸡、雉鸡和鹌鹑8个主要种类,它们多数为国家级保护动物,严禁猎杀.依据这些鸟类危害大豆的特点提出保护性防治措施,主要包括:(1)选择抗旱性强、籽粒小、子叶青色、紫花类型大豆品种,规避鸟类危害;(2)采用以快速集中出苗目标的栽培技术,减轻鸟类危害;(3)采用驱鸟剂和驱鸟器等保护性措施,防治鸟类危害.

  16. Research on design of chemical open experimental teaching:The extraction and separation of Streptomyces allelochemicals%研究创新性化学开放实验教学设计--链霉菌化感活性物质的提取与分离

    Institute of Scientific and Technical Information of China (English)

    李春远; 卢其明; 陈敏; 罗志刚

    2015-01-01

    Streptomyces is the most important genus in actinomycetes since they produce many antibiotics and biologically active compounds.The extraction of allelochemicals is an important step to study allelopathy. Extraction of allelochemicals of Streptomyces strain 6803 as the researching experimental subject is designed. The students design different experimental schemes after reading a lot of papers and carries out the experiment by themselves,the solvent consumption and environmental pollution are remarkably reduced by optimizing extraction.Optimal selection of the methods for extraction and separation can lead to efficient purification of the target compounds. The structures are elucidated by analysis of the nuclear magnetic resonance spectroscopy under the guidance.The researching chemical open experiments help the students promote their awareness of environmental protection,the operating skills and innovative ability,which can improve the quality of education and teaching.%链霉菌属是多数抗生素和化感活性物质的最重要的产生菌,而化感活性物质提取方法的研究是研究化感作用的重要步骤。以一株活性链霉菌6803(Streptomyces srtain 6803)为研究对象,以绿色化学思想为指导,设计链霉菌活性物质提取及分离为开放实验学生的研究性实验,引导学生通过查阅相关研究文献,自行设计实验方案,优选提取及纯化方法,使溶剂消耗及环境污染显著降低;高效率地分离、纯化出目标产物,并用核磁共振谱图鉴定活性物质的结构。该研究性实验设计有助于增强学生的环保意识,提高学生的实验技能及科研创新能力,从而达到提高教育和教学质量的目的。

  17. Effects of Solanum rostratum on seed germination and seedling growth of tomato%黄花刺茄浸提液对番茄种子萌发及幼苗生长的影响

    Institute of Scientific and Technical Information of China (English)

    平亚飞; 朱建雯; 张振国

    2012-01-01

    为明确入侵植物黄花刺茄对当地主栽经济作物番茄种子萌发和幼苗生长的影响,本文采用培养皿滤纸法,在智能光照培养箱的变温控制条件下,分别研究了黄花刺茄根、茎、叶浸提液对番茄种子发芽率、发芽指数及幼苗根长和苗高的影响.结果表明:(1)黄花刺茄不同器官的浸提液对番茄种子发芽率、发芽指数、幼苗根长和苗高的影响不同,其茎、叶浸提液的化感作用较为显著(P<0.01).(2)黄花刺茄同部位浸提液对番茄种子发芽率、发芽指数、幼苗根长和苗高不同指标的影响也不同.根漫提液对种子发芽率、幼苗根长影响不显著(P>0.05),但对种子发芽指数的影响极显著(P<0.01).茎和叶浸提液各浓度对种子发芽指数的影响比种子发芽率、幼苗根长和苗高的影响显著(P<0.01).%Solatium rostratum is a invasive weed, while tomato is a main local cultivated crop. We used the filter paper method in petri dish under variable temperature in illumination box to study the effects of the root, stem and leaf extract of Solarium rostratum on seed germination rate, germination speed, root length and seedling height of tomato. The results showed that: (1) The extract of different organs of Solarium rostratum had different effects on seed germination rate, germination speed, root length and seedling height of tomato, among which the allelopathy effects of the extract of stem and leaf were more significant ( P 0.05 ) for the seed germination rate and root length of tomato, but the effect was more significant on germination speed ( P < 0.01) . The effect of the extract of stem and leaf of Solarium rostratum on germination speed was the most significant ( P < 0.01) .

  18. A new mechanism of invader success: Exotic plant inhibits natural vegetation restoration by changing soil microbe community

    Institute of Scientific and Technical Information of China (English)

    YU Xingjun; YU Dan; LU Zhijun; MA Keping

    2005-01-01

    Since the 1950s of the last century, the exotic plant, Eupatorium adenophorum, has spread rapidly across southwest China, damaging native ecosystems and causing great economic losses. We examined the pH, N, P, K, and organic matter concentrations, and the bacterial community character (by Biolog EcoPlateTM) in soils from sites heavily and lightly invaded by this exotic species. Also, soil from the lightly invaded site was treated with a water extract of E. adenophorum roots to examine the effect of the plant on soil properties. We grew three plant species, one native and two exotic, in pot experiment using soil from heavily invaded site to examine the effects of the soil on these plants growth. The soil analysis demonstrated that the pH, organic matter, total N, total P and total K in soils from the heavily invaded site were only slightly different from those of the lightly invaded site, but concentrations of NH4+, NO3? and available P and K in the heavily invaded site were greater than those in the lightly invaded site. The catabolic activity of soil bacterial community in the heavily invaded site was different from that in the lightly invaded site. The catabolic activity of bacterial community in soils treated by the water extract of E. adenophorum roots changed and became similar to that in soils from the heavily invaded site. The pot experiment showed that the exotic plants growth in heavily invaded soil were not different from in lightly invaded soil; however, the native plant biomass decreased dramatically when grown in soil from the heavily invaded site as compared to soil from the lightly invaded site; and the same phenomenon was found when any potential allelopathic effects by E. adenophorum were eliminated by added activated carbon to those soils. Difference in soil nutrient availability and allelopathy could not explain this phenomenon of the native plant in the soils from the heavily and lightly invaded sites. Changes observed in the soil bacterial

  19. Meeting the demand for crop production: the challenge of yield decline in crops grown in short rotations.

    Science.gov (United States)

    Bennett, Amanda J; Bending, Gary D; Chandler, David; Hilton, Sally; Mills, Peter

    2012-02-01

    There is a trend world-wide to grow crops in short rotation or in monoculture, particularly in conventional agriculture. This practice is becoming more prevalent due to a range of factors including economic market trends, technological advances, government incentives, and retailer and consumer demands. Land-use intensity will have to increase further in future in order to meet the demands of growing crops for both bioenergy and food production, and long rotations may not be considered viable or practical. However, evidence indicates that crops grown in short rotations or monoculture often suffer from yield decline compared to those grown in longer rotations or for the first time. Numerous factors have been hypothesised as contributing to yield decline, including biotic factors such as plant pathogens, deleterious rhizosphere microorganisms, mycorrhizas acting as pathogens, and allelopathy or autotoxicity of the crop, as well as abiotic factors such as land management practices and nutrient availability. In many cases, soil microorganisms have been implicated either directly or indirectly in yield decline. Although individual factors may be responsible for yield decline in some cases, it is more likely that combinations of factors interact to cause the problem. However, evidence confirming the precise role of these various factors is often lacking in field studies due to the complex nature of cropping systems and the numerous interactions that take place within them. Despite long-term knowledge of the yield-decline phenomenon, there are few tools to counteract it apart from reverting to longer crop rotations or break crops. Alternative cropping and management practices such as double-cropping or inter-cropping, tillage and organic amendments may prove valuable for combating some of the negative effects seen when crops are grown in short rotation. Plant breeding continues to be important, although this does require a specific breeding target to be identified. This

  20. (+/-)-catechin: chemical weapon, antioxidant, or stress regulator?

    Science.gov (United States)

    Chobot, Vladimir; Huber, Christoph; Trettenhahn, Guenter; Hadacek, Franz

    2009-08-01

    (+/-)-Catechin is a flavan-3-ol that occurs in the organs of many plant species, especially fruits. Health-beneficial effects have been studied extensively, and notable toxic effects have not been found. In contrast, (+/-)-catechin has been implicated as a 'chemical weapon' that is exuded by the roots of Centaurea stoebe, an invasive knapweed of northern America. Recently, this hypothesis has been rejected based on (+/-)-catechin's low phytotoxicity, instability at pH levels higher than 5, and poor recovery from soil. In the current study, (+/-)-catechin did not inhibit the development of white and black mustard to an extent that was comparable to the highly phytotoxic juglone, a naphthoquinone that is allegedly responsible for the allelopathy of the walnut tree. At high stress levels, caused by sub-lethal methanol concentrations in the medium, and a 12 h photoperiod, (+/-)-catechin even attenuated growth retardation. A similar effect was observed when (+/-)-catechin was assayed for brine shrimp mortality. Higher concentrations reduced the mortality caused by toxic concentrations of methanol. Further, when (+/-)-catechin was tested in variants of the deoxyribose degradation assay, it was an efficient scavenger of reactive oxygen species (ROS) when they were present in higher concentrations. This antioxidant effect was enhanced when iron was chelated directly by (+/-)-catechin. Conversely, if iron was chelated to EDTA, pro-oxidative effects were demonstrated at higher concentrations; in this case (+/-)-catechin reduced molecular oxygen and iron to reagents required by the Fenton reaction to produce hydroxyl radicals. A comparison of cyclic voltammograms of (+/-)-catechin with the phytotoxic naphthoquinone juglone indicated similar redox-cycling properties for both compounds although juglone required lower electrochemical potentials to enter redox reactions. In buffer solutions, (+/-)-catechin remained stable at pH 3.6 (vacuole) and decomposed at pH 7.4 (cytoplasm

  1. Response of Root Border Cells of Vicia faba L.to Volatile Oil from Erigeron canadensis L.%蚕豆根缘细胞对加拿大蓬挥发油的响应

    Institute of Scientific and Technical Information of China (English)

    张红; 贾贵芳; 王亚男; 李群; 马丹炜

    2011-01-01

    Allelopathy is one of the mechanisms by which an invasive alien species, Erigeron canadensis L.(horseweed) invades successfully and spreads rapidly.In order to further explore allelopathic and invasion mechanisms of this species, allelopathic effects ofvolatile oil from this species on root border cells and the activity of pectin methylesterase(PME) of broad bean were studied by aeroponic culture.The results showed that the volatile oil from E.canadensis inhibited the root growth, and the survival rate of root border cells decreased, and the activity of root pectin methylesterase increased.But the stimulating effect gradually lowered down along with the increasing doses of the volatile oil and treatment times.These results suggested that volatile oil from this species caused root border cells death and inhibited the growth of ambient plants.%化感作用是入侵植物加拿大蓬(Erigeron canadensis L.)成功入侵和快速扩散的机制之一.为了深入探讨加拿大蓬的化感机制和入侵枧制,以蚕豆为材料,采用悬空气法研究了加拿大蓬挥发油对根边缘细胞和果胶甲基酯酶的化感效应.结果表明在加拿大蓬挥发油作用下,蚕豆根的生长受到抑制,根缘细胞存活率下降,根果胶甲基酯酶活性升高,但随着挥发油剂量增大和作用时间延长,这种促进效应逐渐降低.这些结果说明加拿大蓬挥发油对根边缘细胞具有致死效应,从而抑制了周围植物的生长发育.

  2. Allelopathic evidence in Brachiaria decumbens and its potential to invade the Brazilian Cerrados

    Directory of Open Access Journals (Sweden)

    Elizabeth Gorgone Barbosa

    2008-08-01

    Full Text Available The aim of this study was to look for evidence of allelochemicals in B. decumbens, in parts of the plant from where they could easily be released to the environment. The germination inhibition of Phalaris canariensis, Lactuca sativa (standard species and Melinis minutiflora, another invasive African grass, was tested using B. decumbens germinating seeds and aqueous leachates of the roots, green and senescent leaves, at 5, 10 and 20% w/v. Both the germinating seeds and the aqueous leachates of B. decumbens reduced the germination of the species tested; the effectiveness of the aqueous leachates increased according to concentration. Apparently, the competitive advantage of B. decumbens in the cerrados could be amplified via allelopathy.Invasão biológica é uma das maiores causas atuais da perda de biodiversidade. Várias espécies que se tornam invasoras produzem substâncias fitotóxicas que aumentam sua capacidade competitiva; assim, a alelopatia é uma estratégia capaz de potencializar o sucesso de invasão. Brachiaria decumbens, uma gramínea africana, invadiu os cerrados brasileiros e representa, atualmente, uma séria ameaça à biota regional. Neste ensaio, verificamos a presença de aleloquímicos em partes de B. decumbens das quais poderiam ser facilmente liberados para o ambiente. Testamos a inibição da germinação de Phalaris canariensis, Lactuca sativa (espécies padrão e Melinis minutiflora (outra gramínea africana invasora usando sementes de B. decumbens e soluções aquosas lixiviadas de suas raízes, folhas verdes e folhas senescentes, a 5, 10 e 20% de peso do material por volume de água. Tanto as sementes como as soluções lixiviadas de decumbens reduziram a germinação das outras espécies; a eficiência dos lixiviados aumentou de acordo com a concentração da solução. Acreditamos que a grande vantagem competitiva de B. decumbens no cerrado possa ser amplificada pela alelopatia.

  3. De novo sequencing and analysis of the Ulva linza transcriptome to discover putative mechanisms associated with its successful colonization of coastal ecosystems

    Directory of Open Access Journals (Sweden)

    Zhang Xiaowen

    2012-10-01

    Full Text Available Abstract Background The green algal genus Ulva Linnaeus (Ulvaceae, Ulvales, Chlorophyta is well known for its wide distribution in marine, freshwater, and brackish environments throughout the world. The Ulva species are also highly tolerant of variations in salinity, temperature, and irradiance and are the main cause of green tides, which can have deleterious ecological effects. However, limited genomic information is currently available in this non-model and ecologically important species. Ulva linza is a species that inhabits bedrock in the mid to low intertidal zone, and it is a major contributor to biofouling. Here, we presented the global characterization of the U. linza transcriptome using the Roche GS FLX Titanium platform, with the aim of uncovering the genomic mechanisms underlying rapid and successful colonization of the coastal ecosystems. Results De novo assembly of 382,884 reads generated 13,426 contigs with an average length of 1,000 bases. Contiguous sequences were further assembled into 10,784 isotigs with an average length of 1,515 bases. A total of 304,101 reads were nominally identified by BLAST; 4,368 isotigs were functionally annotated with 13,550 GO terms, and 2,404 isotigs having enzyme commission (EC numbers were assigned to 262 KEGG pathways. When compared with four other full sequenced green algae, 3,457 unique isotigs were found in U. linza and 18 conserved in land plants. In addition, a specific photoprotective mechanism based on both LhcSR and PsbS proteins and a C4-like carbon-concentrating mechanism were found, which may help U. linza survive stress conditions. At least 19 transporters for essential inorganic nutrients (i.e., nitrogen, phosphorus, and sulphur were responsible for its ability to take up inorganic nutrients, and at least 25 eukaryotic cytochrome P450s, which is a higher number than that found in other algae, may be related to their strong allelopathy. Multi-origination of the stress related proteins

  4. 球形棕囊藻与红树林细菌Flavobacterium sp.相互关系的研究%Relationship of Phaeocystis globosa and mangrove bacteria Flavobacterium.sp

    Institute of Scientific and Technical Information of China (English)

    姜发军; 何碧娟; 许铭本; 雷富; 张荣灿

    2012-01-01

    A bacteria was isolated from Futian mangrove in Shenzhen and was identified as Pseudomonas. Spp. These bacteria had the aigicidal activity on Phaeocystis globosa. When the bacteria was co-cultured with P. Globosa, algae filtrate and hemolytic toxins, the number of live bacteria and cultivable bacteria were studied by method of fluorescence microscopy counting and plate counting. The results showed that when the bacteria were incubated in P. Globosa,and co-cultured with P. Globosa,the bacteria entered the VBNC state quickly. The bacteria could promote P. Globosa the accumulation of hemolysin. When the bacteria cells were placed in dialysis bag and co-culture with P. Globosa, the bacteria did not impact the hemolysin production also P. Globosa .hardly effect on the VBNC state of the bacteria. Almost P. Globosa filtrate of logarithmic phase and stationary phase and hemolytic toxins promoted the bacteria to entering the VBNC state. Hemolysin hemolysin may play an important role to prevent the grazing and inhibiting other competitors (allelopathy).%从深圳福田红树林中分离出一株细菌,对球形棕囊藻有溶藻活性,通过形态鉴定为假单胞菌属细菌.将球形棕囊藻、藻过滤液和提取的溶血毒素与细菌共培养,通过荧光显微计数及平板计数研究活细菌数和可培养细菌数,结果表明:当细菌直接与棕囊藻共培养时,细菌很快进入VBNC状态,细菌能够促进棕囊藻溶血毒素的积累.而将细菌置于透析袋中与棕囊藻一起共培养时,棕囊藻对细菌的VBNC状态影响不大,细菌对棕囊藻溶血毒素的积累无影响.对数期、稳定期棕囊藻培养过滤液和溶血毒素均可使细菌很快进入VBNC状态,溶血毒素可能在球形棕囊藻在被牧食及抑制其他竞争者中(化感作用)扮演着重要的角色.

  5. Potencial alelopático de espécies nativas na germinação e crescimento inicial de Lactuca sativa L. (Asteraceae Allelopathic potential of native species in Lactuca sativa L. (Asteraceae germination and initial growth

    Directory of Open Access Journals (Sweden)

    Fabiana Maraschin-Silva

    2006-03-01

    Full Text Available A alelopatia caracteriza-se pelos efeitos danosos ou benéficos sobre o desenvolvimento da vegetação, causados por substâncias químicas produzidas e liberadas para o ambiente por uma planta. Com o objetivo de avaliar o potencial alelopático de espécies brasileiras, foram testados extratos foliares de Cecropia pachystachya Trec. (Urticaceae, Peltophorum dubium (Spreng. Taub. (Fabaceae, Psychotria leiocarpa Cham. & Schltdl (Rubiaceae, Sapium glandulatum (Vell. Pax (Euphorbiaceae e Sorocea bonplandii (Baill. Burg., Lanj. & Boer (Moraceae, utilizando-se bioensaios de germinação e crescimento e alface (Lactuca sativa L. como planta alvo. Nesses bioensaios, foram usados extratos foliares aquosos nas concentrações de 2 e 4%, preparados por maceração estática com água fria e quente. Os extratos das cinco espécies causaram atraso na germinação dos aquênios da alface, bem como efeitos tóxicos no crescimento das plântulas, com redução e enfraquecimento das raízes. Os resultados obtidos mostraram a presença de substâncias químicas inibidoras nos extratos, revelando potencial alelopático para as cinco espécies avaliadas.Allelopathy is characterized by harmful or beneficial effects on vegetation development, caused by chemical substances produced and released into the environment by the plant. Aiming to assess the allelopathic potential of Brazilian species, aqueous leaf extracts of Cecropia pachystachya Trec. (Urticaceae, Peltophorum dubium (Spreng. Taub. (Fabaceae, Psychotria leiocarpa Cham. & Schltdl (Rubiaceae, Sapium glandulatum (Vell. Pax (Euphorbiaceae, and Sorocea bonplandii (Baill. Burger, Lanj. & Boer (Moraceae were tested on lettuce using germination and growth bioassays. In these bioassays, aqueous leaf extracts were used at concentrations of 2 and 4%, prepared by static maceration with cold and hot water. The five species extracts delayed lettuce germination and produced toxic effects on seedling growth, with root

  6. Effects of aqueous leaf extracts of Populus tomentosa at different ages on the growth and photosynthetic characteristics of its own seedlings

    Institute of Scientific and Technical Information of China (English)

    Meiqiu ZHU; Ying WANG; Bingxiang LIU; Lili ZHANG; Hui WANG; Yuxin YUAN; Kejiu DU

    2009-01-01

    all P. tomentosa extracts, whereas it decreased significantly at higher concentrations. It seemed that aqueous leaf extracts from P. tomentosa were harmful to the photosynthetic structure of its own seedlings, inhibited seedling growth, and led to an eventual decrease of biomass. Extracts from older P. tomentosa leaves had more negative effects on the seedling growth of poplar. The effects on photosynthesis are the more important mechanism of the allelopathy of poplar.

  7. Time-dependent alterations in growth, photosynthetic pigments and enzymatic defense systems of submerged Ceratophyllum demersum during exposure to the cyanobacterial neurotoxin anatoxin-a

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Mi-Hee; Pflugmacher, Stephan, E-mail: stephan.pflugmacher@tu-berlin.de

    2013-08-15

    Highlights: •We examined time-dependent metabolic changes in C. demersum exposed to anatoxin-a. •Biotransformation and antioxidative defense mechanisms responded positively to anatoxin-a. •Decline in chlorophylls contents was detected in company with irreversible plant growth inhibition during exposure to anatoxin-a. •Anatoxin-a exhibits phytotoxic allelopathy by provoking oxidative stress. •Macrophytes may have interactions with anatoxin-a in aquatic environments. -- Abstract: Recently, aquatic macrophytes have been considered as promising tools for eco-friendly water management with a low running cost. However, only little information is available thus far regarding the metabolic capacity of macrophytes for coping with cyanobacterial toxins (cyanotoxins) in the aquatic environment. Cyanotoxins have become emerging contaminants of great concern due to the high proliferation of cyanobacteria (cyanobacterial bloom) accelerated by eutrophication and climate change. Anatoxin-a, one of the common and major cyanotoxins, is suggested as a high priority water pollutant for regulatory consideration owing to its notoriously rapid mode of action as a neurotoxin. In this study, the time-course metabolic regulation of the submerged macrophyte Ceratophyllum demersum (C. demersum) was investigated during exposure to anatoxin-a at an environmentally relevant concentration (15 μg/L). Biotransformation and antioxidative systems in C. demersum responded positively to anatoxin-a through the promoted synthesis of most of the involved enzymes within 8 h. Maximum enzyme activities were exhibited after 24 or 48 h of exposure to anatoxin-a. However, an apparent decline in enzyme activities was also observed at longer exposure duration (168 and 336 h) in company with high steady-state levels of cell internal H{sub 2}O{sub 2}, which showed its highest level after 48 h. Meanwhile, irreversible inhibitory influence on chlorophyll content (vitality) was noticed, whereas the ratio of

  8. Allelopathic effect of lemongrass and sabugueiro on Cuban jute germination/ Efeito alelopático de capim limão e sabugueiro sobre a germinação de guanxuma

    Directory of Open Access Journals (Sweden)

    Andréa Maria Teixeira Fortes

    2007-08-01

    Full Text Available The invasive species Cuban jute (Sida rhombifolia L. is common in no-till areas. It is an important competitor of crops because of a quite effective root system. For this reason, Cuban jute control commonly is made on large-scale applications of chemicals. This study seeks to make a contribution to the control of Cuban jute via allelopathy using hot aqueous extracts of the medicinal species lemongrass (Cymbopogon citratus Stapf. and sabugueiro (Sambucus australis Cham & Schltdl.. The experiment was carried out in two complementary steps: first we attempted to overcome dormancy of the invasive species, and then we investigated the effect of the medicinal species lemongrass and sabugueiro on Cuban jute germination. The seeds were placed in Petri dishes previously autoclaved for 20 minutes at 121°C and then taken to a germination chamber with a photoperiod of 12 hours at 25°C. A potential allelopathic, inhibitory effect was identified on Cuban jute seed germination when the weed was exposed to the hot aqueous extract of both medicinal species.A espécie invasora guanxuma (Sida rhombifolia L. é comum em áreas de plantio direto e destaca-se na competição com a cultura agrícola por apresentar um sistema radicular bastante eficiente; para tanto, seu controle depende comumente de aplicações químicas em larga escala. O presente estudo teve como objetivo avaliar o efeito alelopático do extrato aquoso quente das espécies medicinais capim limão (Cymbopogon citratus Stapf. e sabugueiro (Sambucus australis Cham & Schltdl. sobre a germinação da espécie invasora guanxuma. O experimento foi realizado em duas etapas complementares: primeiramente visou-se à quebra de dormência da espécie invasora e depois, verificou-se o efeito de capim limão e sabugueiro sobre a germinação de guanxuma. O acondicionamento das sementes foi realizado em placas de Petri previamente autoclavadas por 20 minutos a 121°C, dispostas em Câmara de Germinação com

  9. 马铃薯对瓜列当种子萌发的化感作用研究%Allelopathic effect of potato on Orabanche aegyptiaca Pers.seed germination

    Institute of Scientific and Technical Information of China (English)

    王钟; 马永清; 贾锦楠; 董淑琦; 叶晓馨

    2013-01-01

    Orobanche aegyptiaca is a national-class quarantine species in China which is seriously harmful to melons and other economic crops.In this study, four commercial potato varieties ("Xiabodi", "Qingshu 168", "Jizhangshu No.5" and "Kexin No.1") were planted at a pot experiment, and their rhizosphere soils and plant organs (roots, stems and leaves) sampled at different growth stages (seedling, blossoming and tuber forming stages).Allelopathy potential of extracts (methanol and distilled water) of the above samples was measured in terms of germination rates of O.aegyptiaca seeds treated.The potatoes varieties with O.aegyptiaca seed high germination rates were chosen to prevent and kill off O.aegyptiaca seeds on croplands.The results showed that potato stimulated O.aegyptiaca germination, and the allelopathy potential differed with potato variety.The germination rates of O.aegyptiaca seeds treated with extracts of potato rhizosphere soil increased with potato growth.This suggested that potato secreted O.aegyptiaca germination stimulants at certain period of growth which in turn reduced O.aegyptiaca seed bank in the soil.At seedling stage of potato, the germination rate of O.aegyptiaca seeds treated with 10-fold diluted methanol extracts from potato roots was higher than those from the shoot system.Seeds treated with "Xiabodi" showed the highest germination rate (48.5%).At blossoming stage of potato, the germination rate of O.aegyptiaca seeds treated with 10-fold diluted methanol extracts from stems was highest, followed by those treated with root extracts and leaf extracts.Seeds treated with "Jizhangshu No.5" had the highest germination rate (33.0%).At tuber forming stage of potato, the germination rate of O.aegyptiaca seeds treated with 10-fold diluted methanol extracts from shoot system was higher than those from roots.Also seeds treated with "Xiabodi" gave the highest germination rate (51.2%).While the germination rate of O.aegyptiaca seeds treated with root extracts

  10. Effects of leachates from Casuarina equisetifolia on growth and physiological and biochemical characteristics of Terminalia catappa seedlings%木麻黄浸提液对榄仁树幼苗生长及生理生化的影响

    Institute of Scientific and Technical Information of China (English)

    冯剑; 刘强; 王瑾; 罗炘武; 阮长林; 张晓楠

    2016-01-01

    In this study, we tried to introduce Terminalia catappa into coastal Casuarina equisetifolia windbreak to form mixed forest as windbreak, so as to improve efficiency of wind sheltering and sand fixation and the regional ecological envi-ronment. We selected Terminalia catappa of seedling age of 15 d as experimental and irrigate allelochemicals of leachates of Casuarina equisetifolia of concentration of 125 g•L-1 from roots, rhizosphere soil and litter, and studied the effects of allel-opathy of C. equisetifolia on growth, photosynthesis, the damage of membrance system, antioxidant enzyme activity system and proline content of T. catappa seedlings in growing period of 60 d. The results showed that the leachates of roots, litter and rhizosphere soil reduced the survival rates and damaged seedlings of the beginning of the treatment, and significantly af-fected the plant height, leaves, roots biomass of Terminalia catappa seedlings. Therefore, we could deduce that influence plant growth by the composition of different leachates of Casuarina equisetifolia. All the three leachates significantly reduced the net photosynthesis(Pn), stomatal conductance(Ccond), inter cellular CO2 concentration(Ci),transpiration rate(Tr), but significantly increased the water use efficiency(WUE) of the seedlings after 15-45 d since the treatment beginning. No significant effect of leachates from C. equisetifolia on the leaf chlorophyll contents of Terminalia catappa seedling of treat-ment beginning, with the prolong of growth period, but the roots leachates of C. equisetifolia significantly reduced chloro-phyll content of seedling. The seedlings growth period of 60 d, all the three leachates significantly increased the cell mem-brane penetrability and proline content (Pro), but the roots leachate significantly increased the stomatal conductance, inter cellular CO2 concentration, superoxide dismutase in leaves and catalase in roots of T. catappa. The litter leachates increased the stomatal

  11. Atividade alelopática de extratos de diferentes orgãos de Caesalpinia ferrea na germinação de alface Allelopathic activity of extracts from different organs of Caesalpinia ferrea on lettuce germination

    Directory of Open Access Journals (Sweden)

    Andreya Kaliana de Oliveira

    2012-08-01

    Full Text Available A alelopatia pode afetar muitos aspectos da ecologia das plantas, incluindo a ocorrência, crescimento, sucessão de plantas, estrutura das comunidades, dominância, diversidade e produtividade. Neste trabalho, o objetivo foi avaliar o potencial alelopático de diversos órgãos de jucá (Caesalpinea ferrea sobre a germinação de sementes e desenvolvimento de plântulas de alface (Lactuca sativa. Foi usado o delineamento experimental inteiramente casualizado no esquema fatorial 2x5, com dois métodos de extração (25 e 100°C e cinco concentrações do extrato bruto (0, 25, 50, 75 e 100% para cada órgão avaliado: folhas, cascas e vagens maduras de C. ferrea, em quatro repetições de 25 sementes da alface 'Mônica SF FI'. As características avaliadas foram porcentagem de germinação (PG, índice de velocidade de germinação (IVG, porcentagem de plântulas normais (PN e anormais (PA, comprimentos da parte aérea (CPA e da raiz (CR de plântulas de alface. Os extratos de folhas e de vagens de C. ferrea obtidos a quente (100°C reduziram a porcentagem de germinação de L. sativa em relação à testemunha (0%. Nas maiores concentrações dos extratos de todos os órgãos, houve alta PA (atrofiamento da raiz, queima e escurecimento da radícula, encurvamento do caulículo, geotropismo negativo e menor CPA e CR, comparado à testemunha. Os extratos dos diferentes órgãos de C. ferrea apresentam atividade alelopática inibindo o desenvolvimento de plântulas de alface.Allelopathy can affect many aspects of plant ecology, including the occurrence, growth, plant succession, community structure, dominance, diversity and productivity of plants. The aim of this study was to evaluate the allelopathic potential of various organs of jucá (Caesalpinea ferrea on seed germination and seedling development of lettuce (Lactuca sativa. It was used in a completely randomized 2x5 factorial arrangement, with two extraction methods (25 and 100°C and

  12. 飞机草类黄酮3’-羟化酶基因(CoF3’H)的克隆及其在烟草中的表达%Chromolaena odorata Flavonoid 3’-hydroxylase Gene Cloning and Its Expres-sion in Tobacco

    Institute of Scientific and Technical Information of China (English)

    何海旺; 潘华清; 张铙丹; 何龙飞

    2015-01-01

    A flavonoid 3’-hydroxylase gene cDNA sequence was cloned by RACE and RT-PCR techniques fromChromolaena odorata. The obtained full-length cDNA was named asCoF3’H with GenBank accession number HQ268505.1. It is 1628 bp in length, containing a 1524 bp open reading frame, encoding 507 amino acid residues. The amino acid sequence ofCoF3’H con-tains cytochrome P450 domain and cysteine heme binding region (F××G×R×C×G). Homology analysis by DNAMAN software showed that the deducedCoF3’H protein was highly homologous to F3’H proteins from different species.CoF3’H gene was transferred into tobacco byAgrobacterium-mediated genetic transformation. There was higher content of flavonvoids in T2 trans-genic tobacco than in the wild type. This result shows thatCoF3’H plays an important role in flavonoid biosynthesis, and provides a basis for researches on allelopathy and comprehensive utilization ofC. odorata in the future.%利用RT-PCR和RACE技术从飞机草中克隆得到1628 bp的类黄酮3’-羟化酶cDNA的全长序列,命名为CoF3’H, GenBank登录号为HQ268505.1。CoF3’H基因的编码区长度为1524 bp,编码507个氨基酸。氨基酸序列含P450蛋白结构域和半胱氨酸亚铁血红素结合域保守区(F××G×R×C×G),利用 DNAMAN 软件比对显示, CoF3’H 与其他植物的F3’H蛋白的同源性很高。通过农杆菌介导成功地将CoF3’H基因导入烟草, T2代的转CoF3’H基因烟草植株的黄酮含量显著高于野生型。说明CoF3’H在黄酮的生物合成中起重要作用,为后续研究飞机草的化感作用及综合利用提供基础。

  13. Allelopathic Effects of Cyanobacterial Filtrates on Baltic Diatom

    Science.gov (United States)

    Śliwińska, Sylwia; Latała, Adam

    2012-01-01

    Allelopathy may be one of the factors affecting the formation of massive and harmful algal blooms in aquatic environments. Recent studies indicate that blooms of cyanobacteria in the Baltic Sea has grown significantly in last decades, so it is important to determine the allelopathic interactions between the dominant species of cyanobacteria and microalgae. In this work we investigated the influence of allelopathic compounds on the growth of Skeletonema marinoi by addition of cell-free filtrate of the Baltic cyanobacterium Nodularia spumigena cultures grown under different temperature (15-25°C). Additionally the effects of filtrates of both an exponential and a stationary growing culture of N. spumigena were tested on diatom. These studies indicate that high temperature affected the donor species by increasing its production of allelochemicals. The highest drop of growth of analyzed diatom were observed after the addition of cell-free filtrate obtained from N. spumigena grown at 25°C and constituted 70% of their control. N. spumigena was only allelopathic in exponential growth phase, whereas the cyanobacteria filtrate from stationary phase have any effect on S. marinoi. These findings suggest that N. spumigena may reveal allelopathic activity and that the production of allelopathic substances is influenced by the temperature and growth phase of cyanobacteria. Allelopatia może być kluczowym czynnikiem wpływającym na tworzenie się masowych zakwitów sinic w wielu wodnych ekosystemach. Badania pokazują, że zakwity sinic w Morzu Bałtyckim w ostatnich dekadach znacznie się nasiliły, dlatego tak ważne jest określenie stopnia oddziaływania allelopatycznego dominujących w tym akwenie gatunków fitoplanktonu. W przeprowadzonych badaniach określono wpływ związków allelopatycznych produkowanych przez bałtycką sinicę Nodularia spumigena hodowaną w różnych temperaturach (15-25°C) na wzrost okrzemki Skeletonema marinoi. Dodatkowo w niniejszej pracy por

  14. Biogenic volatile organic compounds - small is beautiful

    Science.gov (United States)

    Owen, S. M.; Asensio, D.; Li, Q.; Penuelas, J.

    2012-12-01

    While canopy and regional scale flux measurements of biogenic volatile organic compounds (bVOCs) are essential to obtain an integrated picture of total compound reaching the atmosphere, many fascinating and important emission details are waiting to be discovered at smaller scales, in different ecological and functional compartments. We concentrate on bVOCs below ground to pollination of flowers. Although bVOC emissions from soil surfaces are small, bVOCs are exuded by roots of some plant species, and can be extracted from decaying litter. Naturally occurring monoterpenes in the rhizosphere provide a specialised carbon source for micro-organisms, helping to define the micro-organism community structure, and impacting on nutrient cycles which are partly controlled by microorganisms. Naturally occurring monoterpenes in the soil system could also affect the aboveground structure of ecosystems because of their role in plant defence strategies and as mediating chemicals in allelopathy. A gradient of monoterpene concentration was found in soil around Pinus sylvestris and Pinus halepensis, decreasing with distance from the tree. Some compounds (α-pinene, sabinene, humulene and caryophyllene) in mineral soil were linearly correlated with the total amount of each compound in the overlying litter, indicating that litter might be the dominant source of these compounds. However, α-pinene did not fall within the correlation, indicating a source other than litter, probably root exudates. We also show that rhizosphere bVOCs can be a carbon source for soil microbes. In a horizontal gradient from Populus tremula trees, microbes closest to the tree trunk were better enzymatically equipped to metabolise labeled monoterpene substrate. Monoterpenes can also increase the degradation rate in soil of the persistant organic pollutants, likely acting as analogues for the cometabo-lism of polychlorinated biphenyls (PCBs) Flowers of a ginger species (Alpinia kwangsiensis) and a fig species

  15. 红小豆根系水浸提液对4种受体作物的化感作用%Allelopathic Effect of Adzuki Bean Root Aqueous Extracts on Four Crops

    Institute of Scientific and Technical Information of China (English)

    连慧达; 裴红宾; 张永清; 秦成

    2014-01-01

    For choosing suitable summer-planting adzuki bean crop, this experiment adopted the method of indoor petri dish bioassay to study the allelopathy effect of adzuki bean, radish, cabbage and wheat under different concentrations of adzuki bean root aqueous extracts. The result showed that the adzuki bean had a strong inhibition towards its germination rate and germination index. With the increasing of adzuki bean root aqueous extracts concentration, the seed germination rate and germination index of the three kinds of receptor crops presented a decreasing trend. From the root length, young leaves length, the number of lateral roots, plant height, fresh weight and other forms indicators of seedlings, it was concluded that with the increase of adzuki bean root aqueous extracts concentration, only wheat presented a promoting effect while the other two kinds of receptor crops show inhibitory effect, which were not significant at low concentrations. With the increase of adzuki bean root extracts concentration, the SOD and POD activity of radish and wheat also increased, but the two kinds of enzyme activity of cabbage showed a decreasing trend. The MDA content in seedlings of radish and wheat decreased, but the MDA content in cabbage increased significantly, which showed that receptor crop wheat could be used as rotation crop of adzuki bean, radish also had a great application potential in adzuki bean crop rotation.%为选择适合红小豆的接茬作物,采用室内培养皿生物测定方法,对不同浓度的红小豆根系水提液下红小豆、萝卜、白菜、小麦的化感效应进行了研究。结果表明:红小豆水提液对自身种子发芽率、发芽指数具有极强的化感抑制作用;随着红小豆根系水提液浓度的增大,3种受体作物的种子发芽率和发芽指数均呈现降低趋势;从幼苗的根长、幼叶长、侧根数、株高及鲜质量等形态指标上来看,只有小麦随着红小豆根系水提液浓度

  16. Potential phytotoxic and shading effects of invasive Fallopia (Polygonaceae taxa on the germination of native dominant species

    Directory of Open Access Journals (Sweden)

    Lenka Moravcová

    2011-08-01

    riparian-like habitats where it often encounters U. dioica populations, while F. ×bohemica tends to occur more often in ruderal sites with a high representation of C. epigejos; this might imply that each of the knotweed species exhibits a stronger effect on native species that are dominant in habitats they typically invade. The weakest phytotoxic effect of F. japonica corresponds to the results of previous studies that found this species to be generally a weaker competitor than its two congeners. Although the results of our experiments cannot be taken as a direct evidence for allelopathic effects acting in the field, the demonstrated potential phytotoxic effect of invasive Fallopia species on the germination of native species suggests that allelopathy may play a role in the strong impact of knotweed invasion on species diversity of invaded communities observed in the field.

  17. ESTRESSE OXIDATIVO EM CÉLULAS VEGETAIS MEDIANTE ALELOQUÍMICOS OXIDATIVE STRESS IN VEGETABLE CELLS MEDIATED BY ALLELOCHEMICALS

    Directory of Open Access Journals (Sweden)

    Gustavo Dias de Almeida

    2008-06-01

    Full Text Available A alelopatia é uma interação entre dois organismos, onde um componente é afetado e o outro permanece estável. Esta interação pode ser fonte de descobertas para novos compostos fitotóxicos naturais com baixa toxicidade aos organismos não alvos de controle. A maior parte dos aleloquímicos são metabólitos secundários como os terpenóides, compostos fenólicos e ácido cianídrico, entre outros. A atuação dos aleloquímicos é variada e afeta um grande número de reações bioquímicas, resultando em diferentes modificações fisiológicas nas plantas, como na atividade enzimática, divisão e estrutura de células, permeabilidade das membranas e captação de íons, culminado na redução ou inativação da germinação e crescimento das plantas. Efeitos dos aleloquímicos sobre a fotossíntese e respiração tem sido melhor caracterizados, embora vários trabalhos tenham demonstrado a atuação desses compostos no estresse oxidativo, resultando em um aumento da produção de espécies reativas de oxigênio, os quais em concentrações elevadas são danosos às células. Dessa forma, o conhecimento dos mecanismos de atuação dos aleloquímicos é necessário para o desenvolvimento de técnicas de manejo sustentável na agricultura.Allelopathy is an interaction among two organisms, where one of that is affected and the other stays stable. It can be source for discoveries of new natural phytotoxic compounds with low toxicity to the organisms that are not target of control. Most of the allelochemicals are secondary metabolites like terpenoids, phenolic compounds, organic cyanides and longchain fatty acids. The performance of the allelochemicals can be different according the situations, and it affects a great number of biochemical reactions, resulting in different physiologic modifications in the plants. Allelochemicals could affect different pathways, like, the enzymatic activity, division and structure of cells, permeability of the

  18. 作物格局、土壤耕作和水肥管理对农田杂草发生的影响及其调控机制%Effects of crop pattern,tillage practice and water and fertilizer management on weeds and their control mechanisms

    Institute of Scientific and Technical Information of China (English)

    赵玉信; 杨惠敏

    2015-01-01

    Field weeds pose significant threats to agricultural production.Weed occurrence is affected by many factors,both natural and artificial.Crop pattern,tillage practices and the management of water and fertiliser are three fundamental factors.In this review paper,we summarize the effects of crop species and the temporal and spatial patterns of cropping.We describe the weed control outcomes of different planting modes,and com-pare changes in weed communities under different tillage practices and fertiliser applications.Possible control mechanisms are identified by considering the competition for resources between crops and weeds,crop allelopa-thy and changes in soil seed banks.Reasonable crop rotation,intercropping and mixed intercropping signifi-cantly restrain weed occurrence.No-tillage can increase weed community diversity.Straw mulch can reduce weed density and biomass.The effects of fertiliser application on weeds vary due to differences in crop species, fertiliser amount and type.Long-term balanced fertilisation can reduce weed density but increase weed commu-nity diversity.Irrigation and improved efficiency of natural precipitation use can inhibit upland weeds,and deep water management at appropriate times can effectively control some weeds in paddy fields.We conclude with some suggestions and prospects for future research on weed control.%农田杂草的危害是阻碍农业生产快速、健康发展的主要因素之一。农田杂草的发生受到诸多自然因素的影响和人工措施的调控,而作物格局、土壤耕作和水肥管理是除施用除草剂外最基本的人工干扰措施。本文综述了作物种类和时空格局对杂草的影响,阐述了主要的作物种植模式防治杂草的效果,并比较了不同土壤耕作和水肥管理措施下杂草群落的变化,重点剖析了杂草发生的调控机制,探讨了通过作物与杂草的资源竞争、作物的他感作用及土壤种子库的变化来调控杂草发生

  19. Lake Granbury and Lake Whitney Assessment Initiative Final Scientific/Technical Report Summary

    Energy Technology Data Exchange (ETDEWEB)

    Harris, B. L. [Texas AgriLife Research, College Station, TX (United States); Roelke, Daniel [Texas AgriLife Research, College Station, TX (United States); Brooks, Bryan [Texas AgriLife Research, College Station, TX (United States); Grover, James [Texas AgriLife Research, College Station, TX (United States)

    2010-10-11

    blooms. Our numerical modeling results support the idea that cyanobacteria, through allelopathy, control the timing of golden algae blooms in Lake Granbury. The in-lake experiments in Lake Whitney and Lake Waco also revealed that as golden algae blooms develop, there are natural enemies (a species of rotifer, and a virus) that help slow the population growth. Again, better characterization of these organisms is a high priority as it may be key to managing golden algae blooms. Our laboratory and in-lake experiments and field monitoring have shown that nutrient additions will remove toxicity and prevent golden algae from blooming. In fact, other algae displace the golden algae after nutrient additions. Additions of ammonia are particularly effective, even at low doses (much lower than what is employed in fish hatchery ponds). Application of ammonia in limited areas of lakes, such as in coves, should be explored as a management option. The laboratory experiments and field monitoring also show that the potency of toxins produced by P. parvum is greatly reduced when water pH is lower, closer to neutral levels. Application of mild acid to limited areas of lakes (but not to a level where acidic conditions are created), such as in coves, should be explored as a management option. Finally, our field monitoring and mathematical modeling revealed that flushing/dilution at high enough levels could prevent P. parvum from forming blooms and/or terminate existing blooms. This technique could work using deeper waters within a lake to flush the surface waters of limited areas of the same lakes, such as in coves and should be explored as a management option. In this way, water releases from upstream reservoirs would not be necessary and there would be no addition of nutrients in the lake.

  20. Chemical Composition and Allelopathyc Activity of Essential Oil of Lippia sidoides Cham Composición química y actividad alelopática del aceite esencial de Lippia sidoides Cham

    Directory of Open Access Journals (Sweden)

    Cláudia Araújo Marco

    2012-03-01

    Full Text Available The allelopathy is a process for which products of the secondary metabolism, as terpenes phenolic, of a certain vegetal intervene significantly, generally of antagonistic form, in the development of other species of plants. The objective of this work was to chemically characterize the essential oil of Lippia sidoides Cham. growing in the Cariri cearense region, Brazil, and evaluate the allelopathyc effect of this oil on the germination of lettuce (Lactuca sativa L., arugula (Eruca sativa Mill., and cauliflower (Brassica oleracea L., in pre-plantation application. The monoterpene thymol (84.90% has been identified as the principal constituent in the essential oil. The experiment was done in randomized complete block, in 4 x 3 factorial; being used four essential oil combinations applied in three different species in pre-plantation applications. Emergence velocity index (EVI, germination percentage and mean time to germination (MTG, had been analyzed through daily counting carried out until the 14th day after sowing. Through qualitative analysis performed by gas chromatography coupled with mass spectrometry (GC/MS were identified seven chemical constituents representing 97.82% of essential oil of L. sidoides, being that the constituent present in greater concentration in oil was the thymol (84.90%. Could be verified the occurrence of the negative allelopathyc effect of lettuce crop, because its present low EVI and greater MTG, for the other vegetable species there were no allelopathic effect.La alelopatía es un proceso mediante el cual productos metabólicos secundarios, tales como terpenos fenoles, producidos por una planta en particular interfieren significativamente, y de manera antagónica, en el desarrollo de otras especies vegetales. Nuestros objetivos fueron caracterizar químicamente el aceite esencial de Lippia sidoides Cham., cultivada en la región de Cariri Ceará, y evaluar el efecto alelopático del aceite aplicado en pre-siembra en

  1. Allelopathic effect of aqueous extracts of Eucalyptus globulus Labill. and of Casearia sylvestris Sw. on cropsEfeito alelopático de extratos aquosos de Eucalyptus globulus Labill. e de Casearia sylvestris Sw. sobre espécies cultivadas

    Directory of Open Access Journals (Sweden)

    Grasielle Soares Gusman

    2011-10-01

    Full Text Available Allelopathy is characterized by the harmful or benefic effects caused by secondary metabolites, that are produced by plants, microorganisms or fungi and are released in the environment, on the development of natural biological systems or implemented ones. This study aimed to evaluate the allelopathic effects of aqueous extracts of eucalypt (Eucalyptus globulus Labill. and wild coffee (Casearia sylvestris Sw. on the germination and initial development of mustard (Brassica campestris L., cabbage (Brassica oleracea L. cv. capitata, broccoli (Brassica oleracea L. cv. italica, kale (Brassica pekinensis L., lettuce (Lactuca sativa L. cv. grand rapids, tomato (Lycopersicum esculentum Miller, turnip (Brassica rapa L., rucola (Eruca sativa L. and radish (Raphanus sativus L.. Six concentrations of each aqueous extract were tested (10, 30, 50, 70, 90 and 100% and compared to control (distilled water, with five replicates of each concentration, being ten seeds of each crop distributed in each replicate. The aqueous extracts of E. globulus and C. sylvestris reduced significantly the percentage of seed germination, the index of germination speed and the initial growth of the above ground part and roots of all cultivated species, being the reduction of these parameters higher with the increment of the aqueous extracts concentration, which led to thicker and atrophied roots with a higher number of absorbent hairs. Therefore, the results indicate an existence of allelopathic potential of E. globulus and C. sylvestris.A alelopatia caracteriza-se pelos efeitos danosos ou benéficos que metabólitos secundários produzidos por plantas, microrganismos ou fungos liberados no ambiente exercem sobre o desenvolvimento de sistemas biológicos naturais ou implantados. O objetivo do trabalho foi avaliar o efeito alelopático de extratos aquosos de eucalipto (Eucalyptus globulus Labill. e guaçatonga (Casearia sylvestris Sw. na germinação e no crescimento inicial de

  2. 空心莲子草水浸提液对水稻根缘细胞的化感作用%Allelopathic Effect of Aqueous Extracts of Alternanthera philoxeroides on Root Border Cells of Oryza sativa

    Institute of Scientific and Technical Information of China (English)

    王桂芹; 郑玉华; 张晓娟

    2012-01-01

    increases, and then inhibites, but that from stems was contrary to the effect of leaves, roots and rhizome. Synthesis effect of water - solubility allelopathie substance from differences vegetative organs of A. philoxeroides are arranged as follows: leaves 〉 root and rhizome 〉 stem.

  3. Estudo fitoquímico e alelopático do extrato de caule de sucupira-branca (Pterodon emarginatus Phytochemistry and allelophatic study of Pterodon emarginatus stem extract

    Directory of Open Access Journals (Sweden)

    M.G. Hernández-Terrones

    2007-12-01

    Full Text Available A alelopatia é um dos fenômenos pouco estudados no Cerrado. Trata-se de uma ocorrência natural, resultante da liberação de substâncias capazes de estimular ou inibir o desenvolvimento de outras plantas. Objetivou-se neste trabalho avaliar a ação alelopática de extratos da sucupira-branca (Pterodon emarginatus sobre a germinação e o desenvolvimento da raiz e parte aérea do capim-colonião (Panicum maximum. Bioensaios de germinação realizados em placas de Petri comprovaram que o extrato metanólico do tronco dessa planta, a 150 ppm, inibiu 83% do desenvolvimento da raiz, 75% da parte aérea e 30% da germinação de sementes de capim-colonião. Em casa de vegetação, os resultados de inibição foram de 83% para a parte aérea, 80% para a raiz e 63% para a germinação, mas somente na concentração de 400 ppm. Frações do extrato metanólico bruto obtidas por cromatografia de coluna cromatográfica não reproduziram os resultados de inibição obtidos inicialmente. A fração mais ativa (diclorometano/clorofórmio foi analisada por CG/EM. Ela é constituída fundamentalmente por substâncias alifáticas de cadeia longa: fitol (13,5%, ácido oléico (12,8%, linoleiladato de metila (10,9% e ácido palmítico (6,9%. Foram detectados, também, os compostos 1,2,4-trimetil e isopropilbenzenos (12,2% e as cetonas isoméricas isopropenilmetilcetona e 3-penten-2-ona (7,3%. Três compostos desconhecidos também se destacaram: um de baixa massa molar (98 Da, 13,5% e dois de massa molar elevada (13,6%.Allelopathy is one of the natural phenomena little studied in the cerrado. It is the result of the release of substances capable of stimulating or inhibiting the growth of other plants. The objective of this work was to evaluate the allelophatic action of the white sucupira (Pterodon emarginatus stem extract on the germination and development of colonião grass (Panicum maximum under germination, root and aerial part development of coloni

  4. Study on Germination Characteristics of Perilla frutescens under Simulation Environment of Acid Rain and Bryophyta%模拟酸雨及苔藓植物化感条件下紫苏种子萌发特性的研究

    Institute of Scientific and Technical Information of China (English)

    谢天; 江安娜; 王曼君; 颜凤; 方元平; 项俊

    2012-01-01

    通过模拟酸雨胁迫及苔藓化感作用两种不同的生长环境,初步探讨了模拟酸雨及3种苔藓凤尾藓(Fissidens bryoides)、提灯藓(Mnium hornum)、缩叶藓(Ptychomitrium)种植水对紫苏(Perilla frutescens)种子萌发特性的影响.结果表明,pH为5.0及以上的低浓度模拟酸雨环境对紫苏种子的萌发及幼苗生长影响不大,但随着酸化程度的加深,对紫苏种子萌发的抑制作用明显增加,当pH降到1.0时种子不发芽.紫苏幼苗叶片POD活力随胁迫时间的延长呈先升后降的趋势.而叶片MDA含量除pH为5.0处理组与对照组相近外,其他胁迫浓度下均有显著增加,说明pH低于5.0紫苏幼苗生长受到较严重损害.在苔藓种植水培养环境中,与对照组相比,紫苏种子发芽率、发芽指数、活力指数均随苔藓植物种植水浓度的升高而升高,在浓度为100%时对种子萌发的促进效果最为显著.%By simulating two different growth environment, acid rain stress and moss allelopathy, the effects of acid rain and three bryophyte cultivate water (Fissidens bryoides ,Mnium hornum,Ptychomitrium) on Perilla frutescens seed germination was studied. The results showed that the simulated acid rain with pH lower than 5.0 had little effect on P. frutescens seed germination and seedling growth; as the increasing of acidification, there was a significant inhibition of seed germination, and the seed could not germinate under the pH lower than 1.0. The POD activity in P. frutescens blade increased firstly and then decreased as the stress time prolonged, and the MDA content was decreased when pH was lower than 5.0, suggesting that P. frutescens seedling growth was affected by pH lower than 5.0. In the culture water environment, compared to the control, P. frutescens germination rate, germination index, vigor index increased as the bryophyte planting concentration increasing, and the treatment with the most significant effect was 100% bryophyte planting

  5. Allelopathic Effects and Chemincal Components of the Volatiles from Cedrus deodara Leaves and Branches%雪松枝叶挥发性物质的化感作用及其化学成分分析

    Institute of Scientific and Technical Information of China (English)

    李晓凤; 焦慧; 袁艺; 田胜尼

    2015-01-01

    Allelopathy of the volatiles from isolated leaves and branches of C. deodara to seed germination of Brassica pekinensis, Raphanus sativus and Lactuca sativa were studied in a semi-closed container. The componenets of llelochemicals were determined by GC-MS. The results indicated that germination rate and dry weight of B. pekinensis, R. sativus and L. sativa were not significantly affected by the natural volatiles released by the leaves and branches of C. deodara, but seedling growth was significantly inhibited. The volatile oil from leaves and branches of C. deodara had significant inhibitory effects on the germination rate, germination index, root length and seedling length of seeds of these three vegetables. Germination rate and germination index of L. sativa were inhibited by 92.85%and 96.43%, respectively, while root length of B. pekinensis were inhibited by 51.3%, suggesting that there were potential allelochemicals in the natural volatiles released by the leaves and branches of C. deodara that inhibited seed germination, and that the allelopathic effect of volatile oil was stronger than natural volatile compounds. The chemical components of volatile oil and natural volatile were analyzed. In particular, 37 volatile chemical compounds were identified in volatile oil and 84.64%of these volatiles were α-pinene(24.72%), β-pinene(21.04%) and Caryophyllene(12.42%). 22 volatile chemical compounds were identified in the natural volatile and 52.81% of them were terpenes. The main components were α-pinene(17.16%), β-pinene(11.53%) and Bicyclo[3.1.0]hex-2-ene, 4-methyl-1-(1-methylethyl)-(13.06%). Both the volatile oil and natural volatile shared, but the volatile oil had relatively high terpene content. The components and chemical profile of volatile oil were both more than that of natural volatile, which might be a reason for the stronger allelopathic effect of volatile oil than than that of natural volatile. Seen from the results of analysis, terpenes were the

  6. 不同暴露方式下水生植物化感物质抑藻效应的比较研究%Comparative Study on Antialgal Effects of Allelochemicals from Aquatic Plants under Different Exposure Protocols

    Institute of Scientific and Technical Information of China (English)

    高云霓; 葛芳杰; 刘碧云; 鲁志营; 何燕; 张甬元; 吴振斌

    2015-01-01

    effect were examined. Stronger inhibition on cyanobacterial growth was observed in the low-dose (0.5 mg·L-1) repeated exposure (five times at 2 h interval) group than that in the high-dose (2.5 mg·L-1) single exposure group. The inhibition ratio of nonanoic acid, N-phenyl-1-naphthylamine and caffeic acid in the former group was 1.8, 1.1 and 1.6 times that of the latter group on the 7th day. When nonanoic acid and N-phenyl-1-naphthylamine were repeatedly exposed 10 times at 1h interval, the cyanobacterial growth inhibition ratio decreased with the reduction of single dose. However, the growth ofM.aeruginosa was significantly inhibited by the two allelochemicals when the single dose was as low as 0.1 mg·L-1, with an inhibition ratio up to 50.25% by N-phenyl-1-naphthylamine on the 7th day. The inhibition effects of nonanoic acid and N-phenyl-1-naphthylamine when repeatedly added under dark phase were stronger than that under light phase, the cyanobacterial growth inhibition ratio of the former group was 2.2 and 1.3 times that of the latter group on the 3rd day. All above results indicated that the allelochemicals released by aquatic plants could exert more effective inhibition on the growth ofM.aeruginosa by low-dose repeated exposure than high-dose single exposure. Hence, further study on the antialgal effects of plant allelochemicals through repeated exposure would be helpful for revealing allelopathy mechanism of aquatic plants in natural environments, and guiding their theoretical research and practical application.

  7. 紫茎泽兰入侵过程中生物群落的交互作用%The interaction between biological communities in the process of invasion of Ageratina adenophora

    Institute of Scientific and Technical Information of China (English)

    张红玉

    2013-01-01

    strong allelopathy. 3) Influences soil animal communities by changing the surface habitat and associated litter. 4) Due to changes in composition and function of soil microbial community,changes the form and quantity of available resources of soils , influences and reshapes the biological species interaction model, dynamic feedbacks to the formation of the new pattern of plant community. Then, the paper analyzed and pointed out: 1) In the process of biological invasion, the interaction effect plays an important role in the ecological change of plant community structure and function by the ecological process of multiple levels. 2) An ecological driving force was produced because of the impact of biological invasion on communities, then, it feedback effect to the remodeling of community interaction patterns and reconstruction of the new pattern of community and ecosystem. The complexity of biological invasion on community impact and future developments about the effects of biological invasion on communities and ecosystem were pointed out.

  8. Factors affecting seedling regeneration of Liquidambar formosana in the L.formosana forests in hilly regions of Southeast Hubei,China%鄂东南低丘地区枫香林下枫香幼苗更新限制因子

    Institute of Scientific and Technical Information of China (English)

    王传华; 李俊清; 陈芳清; 杨莹

    2011-01-01

    Aims Liquidambarformosana is an important canopy tree species widely distributed in the plains and mountains from the north-subtropical zone to the tropical zone in China. Full understanding of the natural regeneration processes of tree seedling and limiting factors is important for plant population conservation and forest management. Our objective is to investigate the factors that limit seedling regeneration ofL. formosana under canopies of Formosan sweetgum forests in hilly regions of Southeast Hubei, China.Methods Seedling regeneration of L. formosana occurs sporadically under canopies of mixed pine forests but poorly under Formosan sweetgum canopy. In 2008, we carried out a series of experiments to study factors limiting seedling regeneration of L. formosana under mixed pine forests and Formosan sweetgum forests and tested: (1) effects of lower temperature and soil moisture on seed longevity, (2) effects of forest type, soil type and litter cover on seed survival, (3) litter allelopathy effects on seed longevity and germination, and (4) effects of light intensity under canopies on seedling survival.Important findings Dispersed seeds of L. formosana could germinate immediately at lower temperatures (4-8℃), although such temperatures were fatal to seedling establishment. Contrary to our prediction, soil type, litter leachate and litter cover had no effects on L. formosana seed viability and could not be used to explain poor seedling regeneration under canopies of Formosan sweetgum forest. We also did not find any litter leachate inhibition or promotion effects on seed germination, although a short germination lag effect was found with leachate of pine needles and sweetgum leaves. Shading first-year seedlings of L. formosana indicated that about 90% would die under the canopy of the Formosan sweetgum forest (with its 3% transmittance of open-sky light). In general, our experiments suggested that non-dormant seed and shade-intolerant seedlings of L

  9. Research progress and prospect about exotic invasive species Phalaris minor Retz%外来入侵植物小子虉草研究进展与展望

    Institute of Scientific and Technical Information of China (English)

    徐高峰; 申时才; 张付斗; 张云; 毛佳; 金桂梅

    2015-01-01

    interested in studying this weed species and thus much progress has been made in understanding the biology and ecology of this species of weeds. However, research on P. minor in China has remained largely inadequate, resulting in difficulties in developing reliable early warning and control system for the weed. This paper reviewed some of the hot research issues on P. minor based on the abroad and domestic research results, including its distribution all across the world, the possible reasons for the damage it caused to crops (e. g. interspecific competition, allelopathy), the mechanisms underlying its invasion and spread, genetic variations in the weed population, and the highly adaptive ability and biological characteristics of the invasive weed to explain its highly successful rate of spread (e. g., morphological similarity of P. minor with wheat, small seed size and persistent soil seed bank). The paper also reviewed control methods of P. minor, which were divided into three general categories — manual, chemical and biological. Finally, three areas of future research were proposed: 1) multi-disciplinary mechanisms underlying its invasion and spread; 2) eco-physiological adaptation of the invasive species to global climate change;and 3) effective control of the invasive species. Thus it was very important to build an in-depth research on the invasive species in order to predict and prevent the successful invasion of P. minor, and to eventually lay the theoretical and technical support for the management of P. minor.

  10. 低氮胁迫下小麦抑草作用的化感效应与资源竞争分析%Analysis of allelopathic effects and resource competition of weed suppression ability of wheat (Triticum aestivum) under low nitrogen stress condition

    Institute of Scientific and Technical Information of China (English)

    陈珊; 谢惠玲; 李圆萍; 王微; 肖清铁; 林瑞余; 林文雄

    2014-01-01

    Allelopathic effects and resource competition are critical factors of weed suppression ability of crops. To separate the allelopathic effects from resource competition of weed suppression ability of wheat under low nitrogen stress condition, two strong allelopathic wheat accessions (‘115/Q’ and‘92L89’) and one weak allelopathic wheat accession (‘K10103’) were used in two sets of separate experiments (co-cultivated Alopecurus aequalis with wheat and treating Alopecurus aequalis with hydroponic solutions of co-cultured wheat root exudates) to evaluate bio-interference, allelopathy and resource competition effects. The experiments were conducted in gradient N concentration hydroponic solutions with N levels of 25 mg·L-1, 50 mg·L-1, 100 mg·L-1 and 200 mg·L-1. The results showed significantly differences in the abilities of inhibition to the growth of Alopecurus aequalis in the three wheat accessions in both experiments. Weed suppression ability (inhibitory rate, IR) increased with decreasing N level in all the wheat accessions. The rank order of IR for different wheat accessions was‘115/Q’ (55.1%-73.9%)>‘92L89’ (48.9%-65.9%)>‘K10103’ (15.4%-45.5%). Generally, IR increased with decreasing N level in hydroponic solutions. Both allelopathic effects and resources competition were critical for wheat weed suppression. Different ecological strategies were noted in different allelopathic potential wheat accessions under low N stress condition. Weed suppression ability improved by increasing allelopathic effects of strong allelopathic wheat accessions. This was triggered by enhanced resources competition of weak allelopathic wheat accessions. Allelopathic effects increased with decreasing N level and the changes in inhibitory rate with N level well fitted quadratic equations.%化感效应和资源竞争在作物抑草中起重要作用。为区分低氮胁迫下小麦抑草作用的化感效应与资源竞争,以强化感小麦品种‘115/

  11. Effects of Applying Accumulator Straw in Soil on Growth and Cadmium Accumulation of Galinsoga parviflora%土施富集植物秸秆对牛膝菊生长及镉积累的影响

    Institute of Scientific and Technical Information of China (English)

    汤福义; 林立金; 廖进秋; 廖明安; 何静; 杨代宇; 张潇

    2015-01-01

    To study the allelopathy effects of accumulator straw on hyperaccumulator,a pot experiment was con-ducted to study the effects of applying accumulators (Conyza canadensis,Cardamine hirsuta,Eclipta prostrata and Nasturtium officinale)straws in soil on growth and cadmium accumulation of Galinsoga parviflora under cadmium pollution.The results were as follows:Compared with non-application (control),the application of C.canadensis and C.hirsute straws improved the roots,stems,leaves,shoots and whole plants biomasses of G.parviflora,and the plant height and antioxidant enzymes (SOD,POD and CAT)activity of G.parviflora also increased.The straws of E.pros-trate and N.officinale reduced the biomass,plant height and antioxidant enzyme activity of G.parviflora.The straws of C.canadensis,C.hirsuta,E.prostrata and N.officinale improved cadmium content in shoots of G.parviflora,which improved 1 2.01 %,9.55%,22.03% and 5.39% respectively compared with control,but only C.canadensis and C.hirsuta straws improved the cadmium accumulation in shoots of G.parviflora (which improved by 35.78% and 1 1 .77% respectively compared with control).C.canadensis and C.hirsuta straws increased soil catalase activity, soil urease activity and soil invertase activity,and the straws of E.prostrata and N.officinale reduced soil activity. Therefore,the applying C.canadensis and C.hirsuta straws in soil could improve cadmium contaminated soil remedy ability of G.parviflora,and C.canadensis straw was the best one.%为研究富集植物秸秆对超富集植物的化感作用,通过盆栽试验,研究了镉污染条件下,土施4种镉富集植物(小飞蓬、碎米荠、旱莲草和豆瓣菜)秸秆对牛膝菊生长及镉积累的影响。结果表明:与未施用相比,施用小飞蓬和碎米荠秸秆提高了牛膝菊根系、茎秆、叶片、地上部分及整株生物量,也提高了牛膝菊株高和抗氧化酶(SOD、POD 和CAT)活性,但施用旱莲草和豆瓣菜秸秆

  12. GC-MS identification of chemicals in lily root exudates%百合根系分泌物的GC-MS鉴定

    Institute of Scientific and Technical Information of China (English)

    程智慧; 徐鹏

    2012-01-01

    lower than 0.20%,11 organic compounds were identified in methanol component,mainly derivatives of parabens such as 1,2-benzenedicarboxylic acid,diisooctyl ester(52.11%) and bis(2-ethylhexyl) phthalate(40.95%),and the contents of other compounds were lower than 1%.Six derivatives of parabens were identified in petroleum ether component,such as 1,2-benzenedicarboxylic acid,diisooctyl ester(88.04%),bis(2-ethylhexyl) phthalate(9.06%),and the contents of other parabens were lower than 1%.There were abundant organic compounds identified in chloroform component,totally 19 compounds included esters,aldehyde,phenol,olefin,alkane,and so on.Among them,the contents of the following compounds were over than 1%:1,2-benzenedicarboxylic acid,diisooctyl ester(39.87%),Bis(2-ethylhexyl) phthalate(39.62%),hexadecane(1.36%),2-methoxy-1-(2-nitroethenyl)-3-(phenylmethoxy)-benzene(1.22%),phenol,2,4-bis(1,1-dimethylethyl)(1.02%).The allelopathy of diethyl ether component and the ethyl acetate component were weak and the organic compounds in the two components were not further identified.【Conclusion】 The organic compounds in lily root exudates identified by GC-MS are mainly esters.The higher level compounds in all the three components are the derivatives of parabens.Also there are few aldehyde,phenol and olefin.

  13. Analysis of phenolic acids and terpenoids in rhizosphere soils of different allelopathic rice varieties under dry field conditions%田间旱育条件下不同化感潜力水稻根际土壤酚酸类和萜类物质分析

    Institute of Scientific and Technical Information of China (English)

    孙小霞; 王海斌; 何海斌; 陆锦池; 林文雄

    2014-01-01

    Although phenolic acids and secondary terpenoid metabolites respectively from shikimate pathway and isoprene metabolic pathway are the main plant allelochemicals, it is far from conclusion in academic circles on what allelochemicals cause rice allelopathy. Thus far, most studies on rice root exudates have been conducted in laboratory conditions. Furthermore, few reports have been made on the changes in allelopathic substances in the rhizoshpere soil of different allelopathic potential rice cultivars especially under stressful field conditions. This paper studied the differences in allelopathic compounds including phenolic acids and terpenoids extracted from the rhizosphere soils of strong allelopathic rice cultivar‘PI312777’ and its counterpart ‘Lemont’ and those from the control soil without any plants under dry and wet soil conditions in the seedling nursery. Putative allelochemicals of rhizosphere soil extracts were then identified via GC-MS (Gas Chromatograph-Mass Spectrometer-computer) and HPLC (High-performance liquid chromatography). The results showed that the compositions of phenolic acids and terpenoid compounds were similar but the contents of them were different in different treated rhizosphere soils and controls. Under moderate drought stress, the total content of five phenolic acids such as caffeic acid, 4-hydroxybenzoic acid, vanillic acid, ferulic acid and cinnamic acid, increased in all treated rhizosphere soils, and allelopathic rice‘PI312777’ showed the highest increases in the total content of the five phenolic acids, which was 2.84 times higher than that of control soil under wet treatment. In addition, among 27 detected and identified terpenoids, 17 were oxygenic monoterpenoid compounds in the extracts of rhizosphere soil samples. Under drought stress, the contents of monoterpenes, oxygenated monoterpenes, oxygenated sesquiterpenes and total terpene showed the changing patterns with different extents and different trends in

  14. Efeito alelopático de folhas de Solanum lycocarpum A. St.-Hil. (Solanaceae na germinação e crescimento de Sesamum indicum L. (Pedaliaceae sob diferentes temperaturas Allelopathic effect of Solanum lycocarpum A. St.-Hil. leaves on the germination and growth of Sesamum indicum L.(Pedaliaceae under different temperatures

    Directory of Open Access Journals (Sweden)

    Sarah C. Caldas Oliveira

    2004-09-01

    Full Text Available Alelopatia pode ser definida como o efeito maléfico ou benéfico que uma planta exerce sobre a outra por meio de compostos químicos liberados no ambiente. Diversas espécies do gênero Solanum apresentam evidências de propriedades alelopáticas. S. lycocarpum A. St.-Hil (lobeira é espécie de ampla distribuição em ambientes perturbados do Cerrado. No presente trabalho foram investigados efeitos alelopáticos de extratos de folhas de lobeira na germinação e no crescimento do gergelim (Sesamum indicum L.. Extratos aquosos das folhas foram preparados nas concentrações de 1%, 2%, 3%, 4% e 5% (p/v. A osmolaridade dos extratos foi medida e soluções de polietileno glicol (PEG 6000, de osmolaridade similar, foram preparadas para avaliar possíveis efeitos osmóticos dos extratos aquosos. Nos testes de germinação, as sementes de gergelim foram colocadas em placas de Petri forradas com papel de filtro com a solução a ser testada e observadas a cada 8h. Para os experimemtos de crescimento, sementes de gergelim foram germinadas em água e posteriormente dispostas para crescimento nos extratos. Após 5 dias, foram medidos os comprimentos da parte aérea e radicular das plântulas. Todos os experimentos foram conduzidos a 22 ºC, 30 ºC e 38 ºC. Observou-se que os extratos de folhas não afetaram a germinabilidade, mas aumentaram o tempo médio de germinação em uma relação próxima à dose-dependente, nas três temperaturas. Quanto ao crescimento, a parte radicular foi a mais afetada pelos extratos aquosos, apresentando redução no tamanho, necroses, ausência de pêlos absorventes e formação de raízes laterais. Os efeitos dos extratos no crescimento das plântulas foram mais evidentes a 38 ºC. Os experimentos conduzidos com soluções de PEG 6000 mostraram que os efeitos observados na presença dos extratos não são de natureza osmótica.Allelopathy should be defined as any stimulatory or inhibitory effect by one plant on another

  15. Padrão de resposta de Mimosa pudica e Senna obtusifolia à atividade potencialmente alelopática de espécies de Poaceae Response pattern of Mimosa pudica e Senna obtusifolia to potentially allelopathic activity of Poaceae species

    Directory of Open Access Journals (Sweden)

    A.P.S. Souza Filho

    2010-01-01

    Full Text Available A alelopatia é um importante mediador de interferências que alteram a dinâmica de espécies de plantas em sistemas agrícolas. Neste trabalho, procurou-se determinar a existência de padrão de respostas das plantas daninhas Mimosa pudica e Senna obtusifolia a espécies da família Poaceae, via interação entre espécies e frações e ordenamento dos efeitos. Bioensaios de germinação de sementes e alongamento da radícula e do hipocótilo foram desenvolvidos, em condições controladas. Os testes foram realizados utilizando-se extratos hidroalcoólicos na concentração de 1,0% das frações folha, raiz e sementes de quatro espécies de Poaceae. Diferenças na intensidade dos efeitos para os fatores espécie e fração foram verificadas. O padrão de atividade observado foi de Paspalum maritimum apresentar as inibições mais intensas. Entre as espécies de Brachiaria, as inibições mais intensas foram produzidas por B. brizantha. Houve resposta efetiva para a especificidade entre espécies e fração para a germinação e alongamento da radícula, especialmente na espécie Mimosa pudica. Apenas para os extratos de P. maritimum foram observadas especificidade e efetividade em relação à germinação de sementes e alongamento da radícula da espécie Senna obtusifolia. A fração folha foi mais efetiva nas inibições, sobretudo na espécie P. maritimum. Comparativamente, a espécie Mimosa pudica foi mais sensível aos efeitos dos extratos, especialmente em relação ao desenvolvimento da radícula e do hipocótilo. A intensidade dos efeitos alelopáticos variou na seguinte ordem: alongamento da radícula > germinação de sementes > alongamento do hipocótilo. A ordenação dos resultados, para os indicadores de inibição, indicou discriminação no padrão para as espécies receptoras, o que sugere especificidade dos extratos.Allelopathy is an important device to measure interferences affecting the dynamics of plant species in

  16. Advances in the research of methane oxidation in forest soils%森林土壤氧化(吸收)甲烷研究进展

    Institute of Scientific and Technical Information of China (English)

    邓湘雯; 杨晶晶; 陈槐; 黄志宏; 项文化; 彭长辉

    2012-01-01

    Methane (CH4) is an important greenhouse gas, which is second only to carbon dioxide and about 25% contribution to global warming. Atmospheric methane can be oxidized by methanotrophic bacteria under aerobic condition. There are numerous reports of atmospheric CH4 oxidation and absorption in forest soils. Methanotrophic bacteria are a group of bacteria physiologically defined by their ability to use methane as sole source of carbon and energy for growth. However, it remains considerable uncertainty about the amounts of CH4 released from forest soils to the atmosphere, which depended on the abundance and relative activity of methanogenus and methanotrophic bacteria in forest ecosystems. Most studies have been focused on the environmental effects on the oxidizability and the biochemical properties of methanotrophic bacteria. The oxidation processes were a kind of high capacity and low affinity oxidation, affected by lots of factors, such as soil temperature, soil aeration, soil pH and nitrogen fertilizer. Generally, soil aeration was influenced by soil texture and soil moisture. And soil bulk density, soil structure and moisture were also influenced by land use types, and thereby affecting soil methane oxidation. Soil methane oxidation capacity also could be influenced by plants through changes in habitat or allelopathy. Few studies on soil animals, only termites in the emissions inventory is included in the global methane accounting. Starting from the classification of the methane-oxidizing bacteria, the methanotrophs on methane oxidation mechanism, the ecological distribution of the bacteria and methane oxidation factors, spatial and temporal heterogeneity, observation methods are reviewed. So, this review could provide a theoretical basis to correctly understand and accurately predict forest soil methane oxidation under the conditions of a certain type of climate and land use intensity.%甲烷是一种重要的温室气体,对全球气

  17. The Alleviate Effect of Extracellular DNA and Protein in Maize Root Border Cells on the Allelochemical Stress from Chenopodium ambrosioides L.%玉米根边缘细胞exDNA和胞外蛋白对土荆芥化感胁迫的缓解效应

    Institute of Scientific and Technical Information of China (English)

    胡忠良; 王亚男; 马丹炜; 陈斌; 何亚强; 周健

    2015-01-01

    合物的毒性最小;土荆芥挥发油具有诱导根边缘细胞黏胶层面积增大的效应,并表现出剂量效应,当挥发油剂量达到5μL时,黏胶层相对面积与对照差异显著(P<0.05)。与对照相比,在对伞花素和α-萜品烯的作用下玉米根边缘细胞黏胶层面积变化不显著;当exDNA或胞外蛋白被DNA酶或蛋白酶降解后,根边缘细胞黏胶层相对面积缩小,细胞活性降低,其中,挥发油处理组根边缘细胞活性均在10%以下,对伞花素处理组、α-萜品烯处理组、对伞花素和α-萜品烯混合物处理组根边缘细胞活性虽然有所降低,但仍保持在80%左右。【结论】土荆芥挥发油及其主要成分对伞花素、α-萜品烯具有细胞毒性,可导致玉米根边缘细胞活性降低,根边缘细胞黏胶层中的exDNA和胞外蛋白对土荆芥挥发油、对伞花素、α-萜品烯的细胞毒性具有缓解效应,可在一定程度上缓解土荆芥的化感胁迫。%[Objective]Root border cells (RBCs) are released from the root cap as individual cells or a group of attached cells. The mucilage of root border cells acts in a manner similar to that of neutrophil extracellular traps (NETs) in defense, thus, known as border cell extracellular traps (BETs). The extracellular DNA (exDNA) and proteins are components of border cell mucilage, which have been considered to play a vital role in protecting root tip from biotic and abiotic stresses. Allelopathy is one of the successful mechanisms of exotic plant for invading. The objective of this study is to reveal the roles of the exDNA and extracellular proteins of root border cell mucilage in resistance to allelochemical stress from an invasive plant, Chenopodium ambrosioides L..[Method]Experiments were performed with maize (Zea mays L.)‘Yayu26#’, a widely grown crop in the introduced habitats of C. ambrosioides under aeroponic culture with agar medium. The developmental

  18. Identification of phenolic acids in tobacco root exudates and their role in the growth of rhizosphere microorganisms%烟草根系分泌物酚酸类物质的鉴定及其对根际微生物的影响

    Institute of Scientific and Technical Information of China (English)

    刘艳霞; 李想; 蔡刘体; 张恒; 石俊雄

    2016-01-01

    [Objectives] Tobacco continuous mono-cropping has caused very serious problems, including soil-borne disease outbreak, tobacco growth suppression, yield reduction and quality decline.Allelopathy comes from tobacco and soil microorganisms may be one of the most important reasons leading to mono-cropping obstacle. Tobacco root exudates ( TRE) play a key role in the plant-microorganism interactions in the rhizosphere.It is of great importance to explore effect of tobacco root exudates on rhizosphere microorganisms.[Methods] In this study, the main phenolic acids were screened and identified by the UPLC-Q-TOF/MS method, and their contents in tobacco root exudates were evaluated.Effect of identified phenolic acids from TRE in liqiud medium on pathogen and its antagonist was investigated by applying exogenous phenolic acids.Besides, the soil was added with the identified phenolic acids and cultured for 3 d.After that, the rhizosphere microbial diversities and counts, especially the population of pathogen Ralstonia solanacearum and its antagonist Brevibacillus brevis in the soil were measured.[Results] 1 ) The tobacco root exudates promote the growth of pathogen by 16.8% and suppress the growth of antagonist by 29.4%.2 ) Two phenolic acids are screened and identified by UPLC-Q-TOF/MS with the concentrations of 0.25 μg/g and 1.15 μg/g dry root, respectively.3 ) When the exogenous phenolic acids were added to the culture media, low concentrations of benzoic acid (≤2 μg/L) and 3-phenylpropanoic acid (≤3μg/L) promote the growth of the pathogen and antagonist, and the 4μg/L benzoic acid does not significantly affect R.solanacearum, whereas the population of antagonist is decreased by 90.2%.The 6 μg/L 3-phenylpropanoic acid promotes the growth of the pathogen while inhibits the growth of antagonist by 81.1%.High concentrations of benzoic acid (≥ 4 μg/L ) and 3-phenylpropanoic acid (≥ 7 μg/L ) significantly suppress the pathogen and antagonist.4) When the soil