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1.
Belz RG 《Pest management science》2007,63(4):308-326
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 mechanisms, persistence, selectivity and modes of action, as well as consequences of improved crop allelopathy on plant physiology, the environment and management strategies. Creation of weed-suppressive cultivars with improved allelopathic interference is still a challenge, but traditional breeding or biotechnology should pave the way. 相似文献
2.
Allelopathy is a naturally occurring ecological phenomenon of interference among organisms that may be employed for managing weeds, insect pests and diseases in field crops. In field crops, allelopathy can be used following rotation, using cover crops, mulching and plant extracts for natural pest management. Application of allelopathic plant extracts can effectively control weeds and insect pests. However, mixtures of allelopathic water extracts are more effective than the application of single-plant extract in this regard. Combined application of allelopathic extract and reduced herbicide dose (up to half the standard dose) give as much weed control as the standard herbicide dose in several field crops. Lower doses of herbicides may help to reduce the development of herbicide resistance in weed ecotypes. Allelopathy thus offers an attractive environmentally friendly alternative to pesticides in agricultural pest management. In this review, application of allelopathy for natural pest management, particularly in small-farm intensive agricultural systems, is discussed. 相似文献
3.
Allelopathy studies the interactions among plants, fungi, algae and bacteria with the organisms living in a certain ecosystem, interactions that are mediated by the secondary metabolites produced and exuded into the environment. Consequently, allelopathy is a multidisciplinary science where ecologists, chemists, soil scientists, agronomists, biologists, plant physiologists and molecular biologists offer their skills to give an overall view of the complex interactions occurring in a certain ecosystem. As a result of these studies, applications in weed and pest management are expected in such different fields as development of new agrochemicals, cultural methods, developing of allelopathic crops with increased weed resistance, etc. The present paper will focus on the chemical aspects of allelopathy, pointing out the most recent advances in the chemicals disclosed, their mode of action and their fate in the ecosystem. Also, attention will be paid to achievements in genomics and proteomics, two emerging fields in allelopathy. Rather than being exhaustive, this paper is intended to reflect a critical vision of the current state of allelopathy and to point to future lines of research where in the authors' opinion the main advances and applications could and should be expected. 相似文献
4.
水稻化感物质的代谢途径及基因调控 总被引：3，自引：0，他引：3
水稻化感作用和竞争作用是水稻抑草的两个方面,化感作用是通过水稻植株向环境中释放化感物质实现对杂草的生长抑制作用。水稻化感作用的物质主要有4大类:酚类、萜类、含氮化合物和其他化感物质。水稻酚类化感物质的代谢物质为莽草酸和乙酸-丙二酸;类萜是由乙酰CoA经甲羟戊酸和异戊二烯焦磷酸(IPP)转化而来的,类萜生物合成中起作用的是IPP;含氮化感物质是由不同的氯基酸衍生来的。很多植物次生物质产生的酶基因已得到了克隆。紫外光处理水稻化感材料后12 h和24 h,被诱导的苯丙氨酸氨基裂合酶(PAL)、肉桂酸-4-羟化酶(CA4H)和二萜环化酶的酶活力比紫外光处理的无化感作用水稻中的要高2-4倍。用胁迫相关酶的编码基因对水稻的化感作用进行基因调控研究是探明产生水稻化感物质基因的重要策略。 相似文献
5.
The effects of cover crops on weeds and the underlying mechanisms of competition, physical control and allelopathy are not fully understood. Current knowledge reveals great potential for using cover crops as a preventive method in integrated weed management. Cover crops are able to suppress 70–95% of weeds and volunteer crops in the fall‐to‐spring period between two main crops. In addition, cover crop residues can reduce weed emergence during early development of the following cash crop by presenting a physical barrier and releasing allelopathic compounds into the soil solution. Therefore, cover crops can partly replace the weed suppressive function of stubble‐tillage operations and non‐selective chemical weed control in the fall‐to‐spring season. This review describes methods to quantify the competitive and allelopathic effects of cover crops. Insight obtained through such analysis is useful for mixing competitive and allelopathic cover crop species with maximal total weed suppression ability. It seems that cover crops produce and release more allelochemicals when plants are exposed to stress or physical damage. Avena strigose, for example, showed stronger weed suppression under dry conditions than during a moist autumn. These findings raise the question of whether allelopathy can be induced artificially. © 2019 Society of Chemical Industry 相似文献
6.
Edward I. Newman 《Pest management science》1982,13(6):575-582
Many plant species contain toxic secondary chemicals, but it is still uncertain how often allelopathy (the influence of one plant on another by means of a toxic chemical) actually operates in field conditions. The complexities are illustrated by the effects of couch grass on crop species. It has been suggested that crops could be selected for ability to suppress weeds by allelopathy, but the few attempts at this show only limited promise. More promising appear to be: (a) the production of synthetic herbicides chemically similar to natural plant toxins; (b) the blocking of the production by grassland weeds of chemicals that deter grazers; (c) the chemical control of toxin production by microorganisms in decomposing crop residues. 相似文献
7.
Allelopathic studies of common wheat (Triticum aestivum L.) 总被引：1，自引：0，他引：1
YONGQING MA 《Weed Biology and Management》2005,5(3):93-104
Wheat ( Triticum aestivum L.) is a common name for cereal grasses of a genus of the grass family, cultivated for food since prehistoric times by the people of the temperate zones and now the most important grain crop of those regions. It has allelopathic potential if used as a cover crop for weed control in various cropping systems. Research results indicate that, among modern varieties, there is a variable resistance potential against weeds. Numerous allelochemicals have been identified in wheat, mainly belonging to the categories of phenolic acids, hydroxamic acids and short-chain fatty acids. Some researchers conceived that wheat allelopathy is genetically controlled, but systematic research on gene behaviors is lacking. The negative effects of wheat on other crops under different agricultural production systems have been reported. Research is needed to determine the genetic control of wheat allelopathy prior to the development of allelopathic wheat varieties. Further research is needed to conduct in vitro studies to isolate, identify and quantify allelochemicals from living wheat plants at different growth stages. Also, the relationship between heritages of modern varieties and the allelopathic characteristics of wheat during their evolution and selection by humans is still unclear. There is also a lack of research on the modern varieties as to whether the allelopathic potential can be genetically transferred to the next generation. In the future, more models and assessment systems must be developed to illuminate the essence of allelopathy and the genomes of wheat with allelopathic traits should be constructed to make available allelopathic bioinformation on wheat. 相似文献
8.
Crop cultivars with allelopathic capability 总被引：12，自引：0，他引：12
Allelopathy has potential in integrated weed management. Crop plants have the capability to produce and exude allelochemicals into their surroundings to suppress the growth of weeds in their vicinity. Selection for superior genotypes with allelopathic potential has been carried out in several field crops, and evidence has accumulated that crop cultivars differ significantly in their ability to inhibit the growth of certain weed species. To date, progress has been made in understanding the genetics of crop allelopathic activity, and successful genetic manipulation of this trait has also been demonstrated. However, much more research needs to be carried out in order to have a thorough understanding of the genetic control of allelopathic activity. Several genes might be involved in regulating the production and exudation of allelochemicals. Concerted efforts using advances in plant biotechnology will help to unveil the genetics of this trait. Once the allelopathic genes have been located, a breeding programme could be initiated to transfer the genes into modern cultivars to enhance their allelopathic activity for weed suppression, thereby reducing over-reliance on herbicides. 相似文献
9.
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。 相似文献
10.
Review of the biotechnological applications of rice allelopathy in agricultural production 
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下载免费PDF全文 Ill‐Min Chung Sung‐Kyu Park Muthu Thiruvengadam Ji‐Hee Lee Seung‐Hyun Kim Govindasamy Rajakumar 《Weed Biology and Management》2018,18(2):63-74
An improvement in the allelopathic potential of rice will have a great impact on both low‐input and high‐input management systems. Allelopathy alone is not likely to replace other weed control practices, but it surely functions as a component of integrated weed management technology. Allеlораthу is thе рrосе?? whеrеbу аn organic сhеm?саl (аllеlосhеm?саl) that is rеlеа?еd from one рlаnt influences the growth and dеvеlорmеnt of other plants. Allelochemical biosynthesis, release, environmental fate and action on other plant species can depend on genetic factors or on the environment and their interaction. As a result of these interactions, allelopathy is a complex phenomenon with limited repeatability. The term “allelopathy” has undergone several changes and it has been defined as any direct or indirect harmful or beneficial effect of a plant on another through the production of chemical compounds that it releases into the environment. Rice allelopathy is one of the modes of interaction between receptor and donor plants and could exert either positive effects or negative effects. The development of genetic modification by enhancing crops with allelopathic traits should be done cautiously, given the ecological risk (untoxic and safe for humans and the ecosystem, crop productivity, the ratio of benefit and cost etc.). Finally, this article reviews the agricultural production system allelopathy of novel applications, including the role of allelochemical consortia and their potential use in no‐tillage cropping systems, cover crops or mulches. 相似文献
11.
CHUI HUA KONG 《Weed Biology and Management》2010,10(2):73-80
The development of pest management and control is striving toward a future of sustainable agriculture. Weeds cause serious problems in agricultural ecosystems and attempts to control them have met with limited success. However, many weeds are allelopathic; that is, they can produce and release allelochemicals to interact with other plant competitors and to attack microbes or insect and other animal predators. These allelopathic weeds and their allelochemicals may be put into use for ecological pest management and control or employed for other uses. Currently, little attention has been paid to how allelopathic weeds and their allelochemicals potentially can be utilized as an important part of pest management and control in agricultural ecosystems. This review outlines recent research regarding the potential for pest management and control by allelopathic weeds and their allelochemicals by studying the cases of Ageratum conyzoides, Ambrosia trifida, and Lantana camara and provides examples of allelopathic weeds and their allelochemicals that have been incorporated into ecological pest management and control in China. 相似文献
12.
Duke SO Baerson SR Dayan FE Rimando AM Scheffler BE Tellez MR Wedge DE Schrader KK Akey DH Arthur FH De Lucca AJ Gibson DM Harrison HF Peterson JK Gealy DR Tworkoski T Wilson CL Morris JB 《Pest management science》2003,59(6-7):708-717
Recent research of the Agricultural Research Service of USDA on the use of natural products to manage pests is summarized. Studies of the use of both phytochemicals and diatomaceous earth to manage insect pests are discussed. Chemically characterized compounds, such as a saponin from pepper (Capsicum frutescens L), benzaldehyde, chitosan and 2-deoxy-D-glucose are being studied as natural fungicides. Resin glycosides for pathogen resistance in sweet potato and residues of semi-tropical leguminous plants for nematode control are also under investigation. Bioassay-guided isolation of compounds with potential use as herbicides or herbicide leads is underway at several locations. New natural phytotoxin molecular target sites (asparagine synthetase and fructose-1,6-bisphosphate aldolase) have been discovered. Weed control in sweet potato and rice by allelopathy is under investigation. Molecular approaches to enhance allelopathy in sorghum are also being undertaken. The genes for polyketide synthases involved in production of pesticidal polyketide compounds in fungi are found to provide clues for pesticide discovery. Gene expression profiles in response to fungicides and herbicides are being generated as tools to understand more fully the mode of action and to rapidly determine the molecular target site of new, natural fungicides and herbicides. 相似文献
13.
Stephen Moss 《Pest management science》2019,75(5):1205-1211
Implementation of integrated weed management (IWM) has been poor, with little evidence of concomitant reductions in herbicide use. Non‐chemical methods are often adopted as a means of compensating for reduced herbicide efficacy, due to increasing resistance, rather than as alternatives to herbicides. Reluctance to adopt non‐chemical methods is not due to a lack of research or technology but to a lack of farmer motivation and action. Justifiably, herbicides are often seen as the easier option – their convenience outweighs the increased complexity, costs and management time associated with non‐chemical alternatives. Greater use of non‐chemical alternatives to herbicides will only occur if the following seven aspects are addressed: (i) better recognition of the reasons why farmers are reluctant to use non‐chemical alternatives; (ii) encouraging farmers to adopt a longer‐term approach to weed control; (iii) changing farmers' attitudes to pesticides; (iv) paying more attention to the individual farmer's perspective; (v). greater involvement of economists, social scientists and marketing professionals; (vi) re‐evaluating research and extension priorities; and (vii) changing the mindset of funders of research and extension. If ‘persuasion’ fails to deliver greater implementation of IWM, authorities may resort to greater use of financial and other incentives combined with tougher regulations. © 2018 Society of Chemical Industry 相似文献
14.
Fifty years of herbicide research: comparing the discovery of trifluralin and halauxifen‐methyl 下载免费PDF全文
下载免费PDF全文 Fifty years separate the commercialization of the herbicides trifluralin and halauxifen‐methyl. Despite the vast degree of technological change that occurred over that time frame, some aspects of their discovery stories are remarkably similar. For example, both herbicides were prepared very early in the iterative discovery process and both were developed from known lead compound structures by hypothesis‐driven research efforts without the use of in vitro assays or computer‐aided molecular design. However, there are aspects of the halauxifen‐methyl and trifluralin discovery stories that are substantially different. For example, the chemical technology required for the cost‐effective production of halauxifen‐methyl simply did not exist just two decades prior to its commercial launch. By contrast, the chemical technology required for the cost‐effective production of trifluralin was reported in the chemical literature more than two decades prior to its commercial launch. In addition, changes in regulatory environment since the early 1960s ensured that their respective discovery to commercial launch stories would also differ in substantial ways. Ultimately, the time and cost required to develop and register halauxifen‐methyl demanded a global initial business case while the lower registration hurdles that trifluralin cleared enabled a narrow initial business case mainly focused on the USA. © 2017 Society of Chemical Industry 相似文献
15.
Current status of biological control of paddy weeds in Vietnam 总被引：1，自引：0，他引：1
TRAN DANG KHANH † TRAN DANG XUAN DUONG VAN CHIN ILL MIN CHUNG † ELZAAWELY ABDELNASER ABDELGHANY SHINKICHI TAWATA 《Weed Biology and Management》2006,6(1):1-9
Rice is a staple food in Vietnam and accounts for > 7.7 × 106 cultivated ha, which provide 35.5 × 106 t of rice, of which 4.2 × 106 t were exported in 2004. The enlargement of the cropping area and the enhancement of rice yield have rapidly increased the amount of agrochemicals, including herbicides, in crop production in Vietnam. From 1990–2003, the percentage of herbicides in total pesticides has increased ≈ 10-fold to 30.2%. In addition, the improper use of herbicides caused environmental hazards, unsafe agricultural products, and human health problems. Biological management integrated with traditional weed control techniques might help to reduce the dependence on synthetic herbicides and build eco-friendly, sustainable agricultural production in Vietnam. This paper reviews the efforts in establishing a strategy for biological management of weeds that was conducted in recent years by Vietnamese weed scientists. This has included cropping system management, water and soil management, integrated pest management, and utilization of plant allelopathy as major components of the strategy. Many plants with strong allelopathic potential can be a source for biological weed suppression and soil fertility improvement. The utilization of allelopathic properties in rice might also help to provide new rice cultivars with weed-suppressing characteristics. 相似文献
16.
Approach of allelopathy study with Arabidopsis thaliana (L.) Hevnh. and Neurospora crassa 总被引：2，自引：0，他引：2
KAORI TOMITA-YOKOTANI TAKAKO KATO MOHAMMAD MASUD PARVEZ YASUHEI MORI NOBUHARU GOTO KOJI HASEGAWA 《Weed Biology and Management》2003,3(2):93-97
Allelopathy in Arabidopsis seeds was investigated in the present study because there are few available reports of allelopathy studies regarding the early development stage of the plant life cycle, and because Arabidopsis is widely used as a model plant for molecular biology. When cockscomb ( Celosia cristata ) was incubated together with Arabidopsis seeds, the growth of cockscomb was promoted by Arabidopsis seeds. Exudate of Arabidopsis seeds showed a promotive activity on the growth of cockscomb and Arabidopsis itself. A new method for studying allelopathic mechanisms involving the interaction of the plant Arabidopsis thaliana (L.) Hevnh. and the fungus Neurospora crassa was suggested. Arabidopsis seed exudate and the water-soluble fraction of the exudate promoted Arabidopsis growth and reduced fungal germination, indicating that the seed exudate has a species-selective activity. Conversely, the ethylacetate-soluble fraction inhibited growth of all tested materials in the current study. These results demonstrate that the water-soluble substance(s) released from Arabidopsis seeds have species-selective activity on growth of both plants and microorganisms. 相似文献
17.
Francisco A Macías Juan C
G Galindo Jos M
G Molinillo Diego Castellano Raúl F Velasco David Chinchilla 《Pest management science》1999,55(6):662-665
Plants contain allelochemicals which are their own defence systems and can act as herbicides. Selected examples of guaianolides and heliannuols, which are sesquiterpenes, are discussed in the context of their potential use as natural herbicide templates. 相似文献
18.
Kevin B. Kelley 《Pesticide biochemistry and physiology》2007,89(1):1-11
Auxinic herbicides mimic the effects of natural auxin. However, in spite of decades of research, the site(s) of action of auxinic herbicides has remained unknown and many physiological aspects of their function are unclear. Recent advances in auxin biology provide new opportunities for research into the mode of action of auxinic herbicides. Of considerable interest is the discovery of auxin receptors (TIR1 and possibly ABP1) that may lead to the discovery of auxinic herbicide site(s) of action. Knowledge of auxin-conjugating enzymes and auxin signal transduction components may shed new light on herbicide activity, selectivity in dicots, and mechanisms leading to phytotoxicity in sensitive plants. Analysis of genes induced in response to auxin may provide a novel approach for detection of off-target herbicide injury in crops. For example, the auxin-responsive gene GH3 is highly and specifically induced in response to auxinic herbicides in soybean, and may offer a novel method for diagnosing auxinic herbicide injury. Advances in our understanding of auxin biology will provide many new avenues and opportunities for auxinic herbicide research in the future. 相似文献
19.
A bird's eye review was tried to select the bio‐rational targets from known and novel plant‐specific ones for the molecular design of modern herbicides, which exhibit efficient phytotoxicity at a low‐use rate and preserve a good environment in the 21st century. In phytotoxic sites in the photosynthetic electron transport (PET) system discussed in the present article (Part 1), the generally called bleaching herbicides interfering with the biosynthesis of photosynthetic pigments, chlorophylls and carotenoids, and the biosynthesis of plastoquinone, were considered to be good models for the molecular design of modern herbicides. The PET itself was still considered as an interesting target site for new herbicides, although they need to exert their action in all green leaves of weeds to achieve herbicidal efficacy. Because these herbicides never form a tight binding with D1‐protein, their use‐rate cannot be expected to be as low as the herbicides inhibiting chlorophyll or branched amino‐acid biosynthesis. Other herbicidal targets found in chloroplasts, namely ATP and NADPH formations, have already been omitted from the worldwide biorational molecular design program of herbicides targeting the PET system. 相似文献