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1.
植物寄生线虫现已成为危害农业生产的第二大类病害,其防治迫在眉睫。线虫的生物防治是一种新型的线虫防治策略,主要是利用动植物和微生物及其次级代谢产物对线虫进行防治。植物源次级代谢产物即植物源化合物,源于自然,是植物源农药的核心。相比于化学杀线虫剂,植物源杀线虫剂对环境影响较小、靶向性强且不易使线虫产生抗药性。因此,从植物中获得结构新颖且杀线虫活性好的小分子化合物并将其开发成绿色农药,对于线虫病的防治具有重要意义。本文对杀线虫植物、具有杀线虫活性的植物源化合物及其杀虫机理、植物源杀线虫农药的应用情况展开综述,并对该研究领域进行了展望,希望能为植物寄生线虫病的防治与植物源杀线虫农药的开发利用提供参考和帮助。  相似文献   

2.
近年水稻主要线虫病害的研究进展   总被引:3,自引:2,他引:1  
目前,以拟禾谷根结线虫Meloidogyne graminicola、水稻干尖线虫Aphelenchoide besseyi、水稻潜根线虫Hirschmanniella oryzae、水稻茎线虫Ditylenchus angustus和旱稻孢囊线虫Heterodera elachista为主的水稻寄生线虫侵染水稻以及其它禾本科作物引致的线虫病害,已造成了严重的经济损失。近年来,对拟禾谷根结线虫的致病机制和寄主的防御机制等方面的研究已取得了显著进展,但对其它水稻寄生线虫与寄主互作机制的研究还存在较大空白。水稻寄生线虫的防治多依赖化学农药,抗性品种和生物防治等措施的实施存在一定的局限性。本文对上述5种主要水稻寄生线虫病的发生为害、致病机制以及防治方法等进行了综述,并对水稻寄生线虫致病机理的研究以及抗性品种、生物防治和诱导化合物的应用进行了探讨。  相似文献   

3.
BACKGROUND: The small number of available nematicides and restrictions on the use of non‐fumigant nematicides owing to high toxicity to human and non‐target organisms hinder effective nematode control. The nematicidal efficacy of MCW‐2, a new nematicide of the fluoroalkenyl group, was evaluated against the root‐knot nematode Meloidogyne javanica (Treub.) Chitwood. RESULTS: MCW‐2 showed irreversible nematicidal activity against second‐stage juveniles of M. javanica in vitro, following exposure for 48 h at concentrations as low as 0.5 mg L?1, in contrast to fenamiphos or cadusafos. When exposed to MCW‐2 for shorter periods, motile juveniles became immobile with time after rinsing in water. MCW‐2 at 8 mg L?1 inhibited nematode hatching, which, however, recovered after rinsing in water. In pot and plot experiments, 0.5 mg MCW‐2 L?1 soil and 2 kg MCW‐2 ha?1, respectively, controlled M. javanica similarly to or better than fenamiphos or cadusafos at the same concentrations or at their recommended doses. In the soil, the nematicidal activity of MCW‐2 was less persistent than that of fenamiphos. CONCLUSION: MCW‐2 has potential to be used as a new non‐fumigant nematicide that probably has a novel mode of action. Copyright © 2009 Society of Chemical Industry  相似文献   

4.
Abstract

Plant parasitic nematodes are among the most destructive plant pathogens worldwide and their control is very challenging. Plant essential oils (EOs) have showed a great potential in nematode control. In this work, EOs from 10 aromatic plants acclimatized in Togo were assessed in vitro for their nematicidal activity on the root-knot nematode Meloidogyne incognita. EOs were subsequently analyzed by GC-MS and compounds were tested individually on nematodes. The most potent EOs were: Ocimum sanctum L., Cymbopogon schoenanthus (L.) Spreng and Cinnamomum zeylanicum Blume with EC50/72h values of 282?±?53, 288?±?30 and 355?±?126?mg/L, respectively. The EC50/48h values of tested compounds were 81?±?14, 117?±?33, 128?±?42, 141?±?47, 168?±?40, 216?±?86 and 235?±?43?mg/L for cinnamyl acetate, methyl eugenol, cinnamyl alcohol, acetyl eugenol, isoeugenol, eugenol and benzyl benzoate, respectively. Furthermore, we found a synergistic nematicidal activity when we combined phenylpropanoids compounds with carvone. EOs and their constituents described herein merit further studies, especially in pot experiments before serving as nematicides.  相似文献   

5.
1,2-Dehydropyrrolizidine alkaloids (PAs), known to be nematotoxic in vitro, represent a class of secondary plant metabolites from hundreds of plant species worldwide. Pot experiments with the commercially available PA-containing plants Ageratum houstonianum, Borago officinalis, Senecio bicolor, and Symphytum officinalis demonstrate that Meloidogyne hapla is not per se repelled by these plants as all species were infested with nematodes. However, the development of M. hapla juveniles was completely suppressed on A. houstonianum and S. bicolor. Soil in which A. houstonianum and S. bicolor were cultivated and incorporated contained 200–400 times less nematodes than soil treated with Lycopersicon esculentum. Depending on their qualitative composition of PAs at least some of these plants thus appear to be valuable tools for integrated root-knot nematode management.  相似文献   

6.
7.
Bacterial soft rot is a globally significant plant disease that causes major losses in the production of many popular crops, such as potato. Little is known about the dispersal and ecology of soft‐rot enterobacteria, and few animals have been identified as vectors for these pathogens. This study investigates whether soil‐living and bacterial‐feeding nematodes could act as vectors for the dispersal of soft‐rot enterobacteria to plants. Soft‐rot enterobacteria associated with nematodes were quantified and visualized through bacterial enumeration, GFP‐tagging, and confocal and electron scanning microscopy. Soft‐rot enterobacteria were able to withstand nematode grazing, colonize the gut of Caenorhabditis elegans and subsequently disperse to plant material while remaining virulent. Two nematode species were also isolated from a rotten potato sample obtained from a potato storage facility in Finland. Furthermore, one of these isolates (Pristionchus sp. FIN‐1) was shown to be able to disperse soft‐rot enterobacteria to plant material. The interaction of nematodes and soft‐rot enterobacteria seems to be more mutualistic rather than pathogenic, but more research is needed to explain how soft‐rot enterobacteria remain viable inside nematodes.  相似文献   

8.
Treatments of soil to control plant parasitic nematodes constitute a complex problem because product losses, costs of treatments, efficiency of control and increases of yield are subject to multiple variables. To evaluate the situation, the whole system should be as carefully as possible analysed: nematode species must be identified and population densities determined; economical thresholds and the pedoclimatic conditions which affect distribution and persistence of nematicides should be investigated; rate of mortality that nematicides will induce at different doses and their side-effects on plants and environment need to be known. Although a great amount of information is available, this is often rather scattered, so much work is yet to be done. Integrated control is at present the only economical answer.  相似文献   

9.
BACKGROUND: Many California grape growers use preplant fumigation to ensure uniform and healthy grapevine establishment in replant situations. A field study was conducted to evaluate the performance of subsurface drip‐applied chemical alternatives to methyl bromide on plant‐parasitic nematodes, plant vigor and fruit yield during the 6 year period following replanting. RESULTS: Subsurface drip fumigation with 1,3‐dichloropropene plus chloropicrin and with iodomethane plus chloropicrin had generally similar nematicide activity as methyl bromide in three grape types, while sodium azide was less effective. The combination of 1,3‐dichloropropene plus chloropicrin enhanced vine vigor similarly to methyl bromide. However, all plots treated with alternative fumigants produced less fruit yield than methyl bromide over the 4 years of evaluation. CONCLUSION: Subsurface drip fumigation with alternative chemicals to methyl bromide generally provided adequate management of plant‐parasitic nematodes during the vine establishment period. However, further research is required to increase the performance of alternative chemicals against other components of the replant problem, as grape yield in vines grown in the alternative treatments was lower than in methyl bromide. Copyright © 2011 Society of Chemical Industry  相似文献   

10.
Nematicidal activity of the leaf powder, leaf extracts and formulated leaf extracts of Myrtus communis, an evergreen shrub that is widely distributed in Israel and other Mediterranean countries, was evaluated using the root‐knot nematode Meloidogyne javanica in in vitro and pot experiments. Leaf powder added to sand at 0·1% (w/w) reduced the number of juveniles recovered from the sand by more than 50%. Reduction in galling index and number of nematode eggs on tomato roots was also observed by incorporating the leaf powder at 0·1–0·4% (w/w) in the soil in pot experiments. Leaf powder extracts with methanol or ethanol showed the highest nematicidal activity among all extracts tested. Emulsifiable concentrates of leaf‐paste extract at a concentration as low as 0·005% (a.i., w/w) reduced the number of juveniles recovered from treated sand and the gall index of cucumber seedlings. The extract paste at 26 g m?2 was also effective in reducing the gall index of tomato plants in field‐plot experiments. The leaf powder at 0·2% and the formulated leaf‐paste extract at 0·02% were also nematicidal to Tylenchulus semipenetrans and Ditylenchus dipsaci, but not to Pratylenchus penetrans or Steinernema feltiae. At least three nematicidal compounds were found in the leaf extract upon fractionation by thin‐layer chromatography. The results suggest that the leaf powder and paste extract of M. communis are potential nematicides against root‐knot nematodes.  相似文献   

11.
Ochradenus baccatus is a widely distributed shrub in desert regions of the Middle East and North Africa. This plant's nematicidal activity against the root‐knot nematode Meloidogyne javanica was evaluated because it has been found to contain exceptionally high levels of glucosinolates. In in vitro assays with aqueous extracts of the plant, 100% of second‐stage juveniles were immobilized after exposure to 4% root‐core extract for 48 h; 8% root‐core extract suppressed their hatching by 87%, whereas stem, flower and root bark showed lower activity. Incorporation of root core or bark into the soil, as fresh or dry powder at 1 and 0·5% (w/w), respectively, reduced the number of nematodes recovered from the soil by 95–100%, whereas the flower and stem were much less effective. Results from further pot experiments indicated that only the root bark consistently contains nematicidal compounds which are effective in soil, whereas the nematicidal activity of the root core in soil was inconsistent. The presence of non‐volatile lipophilic and lipophobic nematicidal compounds in the root bark was suggested by extraction with different polar solvents, but these compounds do not seem to be isothiocyanates – glucosinolate‐hydrolysed compounds with nematicidal activity. Very poor host status of Ochradenus baccatus to M. javanica, Mincognita and M. hapla, but with root‐penetration rates of juveniles similar to those in tomato roots, suggest that this plant may be used as a cover plant or trap plant to reduce nematode populations in the soil.  相似文献   

12.
Current environmental awareness has led to a greater demand for alternative nematode control strategies. Three field experiments were established to compare management tactics on cucumber in commercial greenhouses naturally infested with root-knot nematodes (Meloidogyne spp). Cucumber rootstocks which have shown resistance to soil-borne diseases were tested to reveal any resistance/tolerance to root-knot nematodes, and integration of these rootstocks with nematicides was investigated. Metham-sodium and 1,3-dichloropropene (1,3-D) provided good control of nematode populations when their application was followed by the application of a non-fumigant nematicide such as cadusafos or oxamyl. Neither fumigant could provide season-long control of nematode populations, and a further application of cadusafos was required for satisfactory control. The efficacy of metham-sodium was significantly increased when injected into soil in comparison with its application through the drip irrigation system. The use of rootstocks resistant to soil-borne fungal pathogens used together with chemical means of nematode control provided promising results for their further use in integrated strategies as alternatives to methyl bromide. However, the latter was the superior treatment for the control of root-knot nematodes in soil infested with residues of galled roots. Dazomet, metham-sodium nor the non-fumigant nematicides oxamyl and fenamiphos could reduce nematode population as efficiently as methyl bromide. None of the chemicals tested except methyl bromide could enter galled roots and kill surviving nematodes.  相似文献   

13.
Few plant parasitic nematodes are currently included in the European Union (EU) regulated pest lists. However, many plant parasitic nematodes not present in the EU are known to be damaging and present a risk to Europe. Therefore a study was performed to assess the risk of importing plant parasitic nematodes with the soil attached to plants for planting, with emphasis on plants in pots. Prior to the survey, a list of harmful plant parasitic nematodes not present within Europe was prepared per continent based on a literature review. This resulted in a Risk List of 26 species. Additionally, over a 3‐year period a survey was carried out on plants for planting imported to the Netherlands with adhering soil, focusing on all plant parasitic nematodes and with special attention to the nematodes on the Risk List. A total of 258 soil samples were studied, originating from 54 different plant species and 20 different countries. Despite the small number of samples, several quarantine nematodes and species from the Risk List were detected, including new nematode–plant combinations. This survey illustrates that plants with adhering soil can be a pathway for the introduction of listed nematodes, including those from the Risk List, to the EU/EPPO region. This information might encourage a more risk‐based approach to performing import inspections.  相似文献   

14.
植物寄生线虫乙酰胆碱酯酶结构与功能研究进展   总被引:1,自引:0,他引:1  
乙酰胆碱酯酶通过水解神经递质乙酰胆碱使得神经信号能够在生物体内进行正常的传递,从而有效调节正常的肌肉活动,在生物体神经传导的过程中发挥着重要作用。植物寄生线虫乙酰胆碱酯酶具有由多种基因编码的不同分子型,在线虫化感、运动、取食、抗药性等多个方面承担着不同的功能。本文简要综述了植物寄生线虫乙酰胆碱酯酶分子型、基因结构、基因功能、组织表达及其在线虫抗药性中的作用等方面的研究进展。  相似文献   

15.
生物防治不仅作为植物寄生线虫病安全有效的防治措施,而且其具有降低化学农药施用量和减少环境污染的作用。木霉菌作为一种生防潜力巨大的线虫病防治真菌,已被广泛研究并应用于植物寄生线虫病的防治。本文主要从木霉防治植物寄生线虫病的直接和间接生防机制的视角,综述了木霉对线虫的重寄生作用、毒杀作用以及木霉对植物的诱导抗性、促生作用等多种协同防治植物寄生线虫的机制,展望了今后需要继续扩大对杀线木霉资源种类的调查和挖掘、木霉菌对植物寄生线虫的作用机理以及从分子水平上加深对木霉防治线虫病机制的研究,旨在为科学利用木霉菌防治植物线虫病提供参考。  相似文献   

16.
Plant products are receiving greater attention as prophylactics against several species of plant-parasitic nematodes. Numerous experiments have shown the potential nematicidal value of plant parts and their by-products when incorporated into soil or when the plants themselves are interplanted as seedlings among crop plants. Various products (oils, cakes, extracts, etc.) prepared from the leaves and seeds of the neem plant (Azadirachta indica A. Juss) (Family Meliaceae) have been reported as effective protectants against nematode pests when used as root-dips and seed treatments. Nemato-toxic compounds of the neem plant, especially the azadirachtins, are released through volatilization, exudation, leaching and decomposition. The modes of action of these compounds are complex, and a number of mechanisms in relation to nematode management are yet to be fully explored. This review critically assesses the potential of these products in the management of nematodes in tropical agriculture.  相似文献   

17.
BACKGROUND: Because methyl bromide has been phased out as a soil sterilant, new nematicides are urgently needed. Four different chemical classes of organic acids acting as anion transport (AT) blockers were tested against a free-living nematode, Caenorhabditis elegans Maupas, a plant-parasitic nematode, Meloidogyne incognita (Kofoid and White) Chitwood, and an entomopathogenic nematode, Heterorhabditis bacteriophora Poinar, in toxicity bioassays. The materials tested were DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid), 9-AC (anthracene-9-carboxylic acid), NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid] and IAA-94 (indanyloxyacetic acid). RESULTS: All the compounds showed slowly developing nematicidal activity against second-stage juveniles of M. incognita and adults of C. elegans, but not against H. bacteriophora infective-stage juveniles. The LC(50) values of these compounds were < 50 mg L(-1) after 48 and 72 h incubation, while at 168 h incubation the LC(50) values were < 10 mg L(-1) for both sensitive species. Across both species and time, the LC(50) values generally differed no more than twofold among the four compounds tested in this study. In contrast, none of the compounds (200 mg L(-1)) caused more than control mortality to H. bacteriophora, even after 168 h of incubation. CONCLUSION: These compounds are potential leads for commercial nematicides. The insensitivity to H. bacteriophora is consistent with the natural exposure of this nematode to DST (3,5-dihydroxy-4-isopropylstilbene), a stilbene produced by its symbiotic bacterium. Based on the known activity of the compounds used in this study, it is suggested that anion transporters form the probable target sites for DIDS, 9-AC, NPPB and IAA-94 in nematodes.  相似文献   

18.
Damage caused by nematodes is one of the limiting factors in crop production. Traditional nematode management is based on the use of crop rotations, resistant cultivars, nematicides, or combinations of these methods. For a crop like peanut (Arachis hypogaea), cultivars resistant to root-knot nematodes are not available. There are soybean (Glycine max) cultivars resistant to some of the species of root-knot nematodes (Meloidogyne spp.); however, most fields have nematode infestations composed of mixtures of species. Research at Auburn has shown that tropical crops can be used effectively in rotation to manage nematode problems. Rotations with American jointvetch (Aeschynomene americana), castor (Ricinus communis), hairy indigo (Indigofera hirsuta), partridge pea (Cassia fasciculata), sesame (Sesamum indicum), and velvetbean (Mucuna deeringiana) have resulted in good nematode control and increased yields of peanut and soybean. Some crops (castor, sesame) are considered ‘active’ in that they produce compounds that are nematicidal, whereas others (e.g. corn, sorghum) are simply non-host, that is, ‘passive’.  相似文献   

19.
20.
The complete phase-out of methyl bromide from use in developed countries by 1 January 2005 will cause many problems in agricultural industries that are now heavily reliant on its use. Three field experiments were established to compare management tactics on tomato and cucumber in commercial greenhouses naturally infested with root-knot nematodes (Meloidogyne spp). Reduction of nematode juveniles in soil and roots to nil detection levels was observed in all plots following soil fumigation with methyl bromide. A significant reduction of nematode juveniles and root-galling index was observed in plots treated with metham-sodium, dazomet and 1,3-dichloropropene compared with the control and plots treated with non-fumigant nematicides. Reduction of the nematode population led to an increase in fruit yield. However, data collected from the second cultivation season indicated that single control methods such as fumigant or contact nematicides alone cannot drastically decrease initial nematode population and those nematodes which escape control lead to population increase by the end of the cropping season.  相似文献   

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