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 共查询到19条相似文献,搜索用时 390 毫秒
1.
席家文  娄巍 《植物检疫》1995,9(2):97-98
独脚金的生物学及危害席家文,娄巍(珲春动植物检疫局133300)独脚金属为玄参科的半寄生或寄生性杂草。在亚、非洲,澳大利亚热带和亚热带地区大约有60种,黄独脚金Strigaasiatica、埃及独脚金S.hermonthica、独脚金S.gesner...  相似文献   

2.
独脚金(Striga asiatica(L)O.kunt,ze,异名Striga lutea Lour)是玄参科独脚金属中很重要的半寄生杂草,严重威胁着农业生产。通常寄生在玉米、甘蔗、高梁、小米、燕麦、稻的根上,也寄生在番茄和某些荚豆、豇豆和禾本科的苏丹草、大刍草、马唐等的根上。  相似文献   

3.
独脚金(Striga asiatica)是玄参科的寄生植物之一,很久以来就给农作物生产造成灾害。独脚金和它的姊妹植物 S.hermon-thica,S.gesnetioides 和 S.euphrasioides早已遍及东半球热带地区,非洲,印度,以及热带和亚热带的许多地区。据报道,在非洲大陆、这些寄生杂草比任何病虫害对作物造成的危害都大。因为独脚金寄生于根部,吸收作物的养料和水分。这种危害较之根据寄生物的生物  相似文献   

4.
王定国  林剑峰 《植物检疫》1994,8(3):162-163
寄生杂草独脚金种子电镜扫描和检疫王定国,林剑峰,陈加平(黄埔动植物检疫局510700)独脚金属StrigaLour.是一类半寄生性恶性杂草,没有根,主要靠吸器在寄主根上吸收营养和水分,对多种作物,如玉米、甘蔗、高粱等造成严重危害。对此恶性杂草,有关植...  相似文献   

5.
寄生在其它高等植物根部的高等植物一列当和独脚金这两个属内的种,既是杂草,又是寄生植物。作为杂草,它们对环境表现出较强的适应性、抗逆性和多实性。它们的种子生命力强,埋藏于土壤中,经历多年仍  相似文献   

6.
列当(Orobanche spp.and Phelipanche spp.)是一种在世界范围内危害严重的根寄生杂草,防除列当的研究也越来越多。正确地采集和预培养列当种子是获得正确防除列当研究结果的前提。列出了大田正确采集列当种子的方法,以及对采集到的种子进行过筛提纯、加洗洁精和吐温20清洗后,再表面消毒和预培养,并通过发芽试验检验此方法的可行性。结果表明,经过处理的向日葵列当、瓜列当种子的发芽率最高分别为54.4%、59.1%。此方法可以应用于列当的采集和预处理过程中,可为列当研究和防除提供参考。  相似文献   

7.
向日葵列当Orobanche cumana是一种检疫性恶性寄生杂草。本研究采用透析法制备了一种水溶性氟乐灵纳米制剂(Tf-OR-CC),评价其对向日葵列当的室内毒力和田间药效。种子发芽毒力测定结果表明:在独脚金内酯类似物GR24的诱导下,用5μg/mL Tf-OR-CC处理向日葵列当种子,7 d后表现出良好的抑制发芽活性,列当种子发芽率为28.5%,与对照相比差异显著。消解动态试验表明,Tf-OR-CC消解半衰期比48%氟乐灵乳油延长6.56 d,说明Tf-OR-CC具有一定的缓释作用。田间药效试验结果表明,滴灌施用有效成分含量为75 g/667 m~2Tf-OR-CC 45 d后,向日葵列当寄生率为32.1%,寄生强度为5.3,Tf-OR-CC制剂对向日葵列当的田间防效为36.3%。该方法可为向日葵滴灌施药技术防治向日葵列当提供科学依据。  相似文献   

8.
寄生杂草菟丝子属及其防治与检疫   总被引:3,自引:0,他引:3  
危害田园作物的主要恶性寄生杂草有:旋花科(Convolvulaceae)的菟丝子属(Cuscuta)、列当科(Orobanchaceae)的列当属(Orobanche)、玄参科(Scrophulariaceae)的独脚金属(Striga)、樟科(Lauraceae)的无根藤属(Cassytha)和桑寄生科(Loranthaceae)的桑寄生属(Viscum)等。本文主要阐述了对农业生产造成严重危害的菟丝子属的生物学特性、种子萌发和休眠以及与外界条件的关系、寄生物的营养方式、繁  相似文献   

9.
列当杂草及其防除措施展望   总被引:1,自引:0,他引:1  
根寄生杂草列当Orobanche spp.每株可产生大量细小的种子,易于传播,且在出苗前已经对寄主作物造成危害,使列当的防除成为一个世界性难题。本文详述了列当的生活史、为害现状以及防除措施,并突出了生物防除的生态效益与经济效益。基于"诱捕"作物及"捕获"作物诱导列当种子"自杀发芽"理论的防除机制,本文提出了新型可持续生态防除思想,为列当科杂草防除提供参考。  相似文献   

10.
为了解锁阳(Cynomorium songaricum)寄生生长特性,使用物理方法和化学方法对其种子进行萌发诱导处理,观察萌发情况。结果表明:锁阳种子较小,成熟的种胚发育不完全,萌发前后处于球形原胚阶段。试验结果证明,锁阳种子萌发的启动,需有来自寄主根中的某种萌发刺激信号;外源赤霉素(GA3)及乙烯溶液对种子休眠的破除...  相似文献   

11.
Damage caused by Orobanchaceae root parasitic weeds is a substantial agricultural problem for global food security. Many studies have been conducted to establish practical methods of control, but efforts are still required for successful management. Seed germination of root parasitic weeds requires host-derived germination stimulants including strigolactones (SLs). Studies on SLs have revealed that a butenolide ring is the essential moiety for SL activity as a germination stimulant. Interestingly, recent studies have revealed that butenolide hormones regulate the biosynthesis of secondary metabolites and mediate communication in actinomycete bacteria. Because of the structural similarity between SLs and the bacterial butenolides, we evaluated the germination stimulatory activity of butenolides isolated from Streptomyces albus J1074 on root parasitic weeds. These butenolides were found to specifically induce seed germination of Orobanche minor. Our findings contribute to understanding the molecular mechanisms of germination stimulant perception and to the development of a method for their biological control.  相似文献   

12.
Various Orobanche species are weedy and cause severe reduction in the yields of many important crops. The seeds of these parasitic weeds may remain dormant in the soil for many years until germination is stimulated by the release of a chemical signal from a host plant. In order to determine the effects of fenugreek root exudate on the induction of Orobanche crenata, Orobanche ramosa and Orobanche foetida seed germination, root exudate was collected from hydroponically grown fenugreek seedlings. Fractionation patterns obtained from column and thin layer chromatography of the fenugreek root exudate showed a set of metabolites differing in their polarity with stimulatory activity on Orobanche seed germination. The crude root exudate stimulated both O. ramosa and O. crenata seed germination to the same level caused by the synthetic germination stimulant GR24 at 10 mg L?1. It also stimulated O. foetida seed germination which did not respond to GR24. Active fractions of root exudate stimulated the germination of Orobanche species differentially.  相似文献   

13.
In vitro culture of Orobanche ramosa   总被引:3,自引:0,他引:3  
Orobanche spp. (broomrapes) are holoparasites that subsist on the roots of many important crops and can considerably reduce yield. The control of Orobanche spp. includes physical, chemical and biological methods. Interactions between parasitic angiosperms and their hosts first occur at the level of parasite seed germination. The seeds of all Orobanchaceae germinate in soil under natural conditions only in response to specific chemical exudates from the host plant. This study describes the influence of different plant growth regulators and host plant root exudates on germination and development of calli from Orobanche seeds in vitro . The effect of indole-3-acetic acid, gibberellic acid and kinetin on the germination of Orobanche seeds varied with concentration. These plant growth regulators also affected the period of germination and the structure of calli and protrusions. An in vitro system for the collection of tobacco root exudates was established. Compounds released from the host roots of three different tobacco cultivars were found to provoke high levels of germination of the Orobanche seeds without any period of pre-conditioning. This study developed methods for the investigation of host–parasite interactions and the effect of germination stimulants in Orobanche spp.  相似文献   

14.
Phelipanche ramosa (Branched broomrape) is an obligate root parasitic plant that is a major pest of oilseed rape in France. Knowledge on seed viability and dormancy under field conditions is crucial to understand how to control P. ramosa, but is as yet unknown. Our study aimed to quantify these processes with a 2‐year seed burial experiment. Two genetically distinct populations of P. ramosa were studied, collected on winter oilseed rape (population O) and hemp (population H). Seed mortality was very low in both populations (4–7% per year). Although obligate parasitic seeds are assumed to germinate only after exposure to germination stimulants from host root exudates, a high proportion of population H seeds germinated spontaneously (up to 90%). Seeds of both populations displayed seasonal dormancy, with timing and magnitude depending on the population. Dormancy was low at the time each native host crop is usually sown. Populations differed in germination dynamics, with seeds of population H germinating faster. The difference in behaviour that we observed between populations is consistent with reported adaptations of pathovars to their preferred hosts. The results indicate that the parasitic plant management requires targeting at the populations concerned. For example, delayed sowing is more promising against population O than against population H.  相似文献   

15.
BACKGROUND: Orobanche and Phelipanche species (the broomrapes) are root parasitic plants, some of which represent serious weed problems causing severe yield losses on important crops. Control strategies have largely focused on agronomic practices, resistant crop varieties and herbicides, albeit with marginal success. An alternative control method is the induction of suicidal seed germination with natural substances isolated from root exudates of host and non‐host plants. RESULTS: Soyasapogenol B [olean‐12‐ene‐3,22,24‐triol(3β,4β,22β)] and trans‐22‐dehydrocampesterol [(ergosta‐5,22‐dien‐3‐ol, (3β,22E,24S)] were isolated from Vicia sativa root exudates. They were identified by comparing their spectroscopic and optical properties with those reported in the literature. Soyasapogenol B was very specific, stimulating the germination of O. minor seeds only, whereas trans‐22‐dehydrocampesterol stimulated P. aegyptiaca, O. crenata, O. foetida and O. minor. CONCLUSION: Soyasapogenol B and trans‐22‐deydrocampesterol were isolated for the first time from Vicia sativa root exudates, and their biological activity as stimulants of Orobanche or Phelipanche sp. seed germination was reported. Copyright © 2011 Society of Chemical Industry  相似文献   

16.
The root parasitic weeds Phelipanche ramosa (branched broomrape) and P. aegyptiaca have the widest host range among Orobanche and Phelipanche species. In Western Europe, P. ramosa attacks, with increasing aggressiveness, crops such as oilseed rape, tobacco, hemp, and tomato. The unique biology of root parasites, establishes a closed link with their host plant, thus reducing the possibility to successfully control them. Control measures include (a) physical processes (such as weeding, solarization, deep ploughing, burning off, flooding), (b) chemical (like soil fumigation, use of herbicides, germination stimulants) and (c) biological methods (e.g. resistant varieties, use of fungi and insects as antagonists, trap and catch crops). German tobacco growers rely mostly on the herbicide method. They apply glyphosate in very low concentrations, when the first tubercles are formed. Also a fungal antagonist against the parasitic weed on tobacco was found in Germany, but until now has not been developed into a commercial mycoherbicide. After hemp production lost its significance as a crop in Germany, tobacco remained as the main host for P. ramosa. In the past 10 years, branched broomrape has spread out and currently it can be found in areas where previously were free of it. Since the elimination of EU subsidies, some tobacco growers began to cultivate on their land parsley instead of tobacco. As a result, parsley has now been infected with P. ramosa. When used 10 years ago as catch crop, parsley had a rather small effect on branched broomrape. This potential danger, especially by other potential host plants, such as oilseed rape, tomato and potato or even weeds should not be underestimated. Spread and expansion of the host plant spectrum of branched broomrape in Germany might be reduced by the introduction of appropriate phytosanitary measures and improved information policies.  相似文献   

17.
Root parasitic plants of the family Orobanchaceae cause severe damage to important agricultural crops worldwide. These parasitic weeds are difficult to control since most of their lifecycle occurs belowground. This hinders the diagnosis of infection and normally when irreversible damage has been caused to the crop. Therefore, new and more effective control strategies against these parasitic weeds should be focused on the initial stages of the interaction. Using tomato-Phelipanche ramosa as model system, we have explored the host response during the initial phase of parasitic infection by monitoring the expression of marker genes of different defense-related hormonal pathways. Two different colonization stages were selected and analyzed by quantitative real-time PCR. The data suggest that the three principal defense regulating hormonal pathways - salicylic acid (SA), jasmonic acid (JA) and abscisic acid (ABA) - are induced after infection, being therefore, likely involved in the defense response against these root parasites. In addition, an induction of the strigolactone (SL) biosynthesis genes SlD27 and SlCCD8 was observed. Our results suggest a complex regulation of plant defenses during the early stages of plant-parasite interaction involving the classical defense hormones, and suggest an additional role of the parasite germination stimulants SLs at this post-attachment stage.  相似文献   

18.
Parasitic weeds of the genera Striga and Orobanche spp. cause severe yield losses in agriculture, especially in developing countries and the Mediterranean. Seeds of these weeds germinate by a chemical signal exuded by the roots of host plants. The radicle thus produced attaches to the root of the host plant, which can then supply nutrients to the parasite. There is an urgent need to control these weeds to ensure better agricultural production. The naturally occurring chemical signals are strigolactones (SLs), e.g. strigol and orobanchol. One option to control these weeds involves the use of SLs as suicidal germination agents, where germination takes place in the absence of a host. Owing to the lack of nutrients, the germinated seeds will die. The structure of natural SLs is too complex to allow multigram synthesis. Therefore, SL analogues are developed for this purpose. Examples are GR24 and Nijmegen‐1. In this paper, the SL analogues Nijmegen‐1 and Nijmegen‐1 Me were applied in the field as suicidal germination agents. Both SL analogues were formulated using an appropriate EC‐approved emulsifier (polyoxyethylene sorbitol hexaoleate) and applied to tobacco (Nicotiana tabacum L.) fields infested by Orobanche ramosa L. (hemp broomrape), following a strict protocol. Four out of 12 trials showed a reduction in broomrape of ≥95%, two trials were negative, two showed a moderate result, one was unclear and in three cases there was no Orobanche problem in the year of the trials. The trial plots were ca 2000 m2; half of that area was treated with stimulant emulsion, the other half was not treated. The optimal amount of stimulant was 6.25 g ha?1. A preconditioning prior to the treatment was a prerequisite for a successful trial. In conclusion, the suicidal germination approach to reducing O. ramosa in tobacco fields using formulated SL analogues was successful. Two other options for weed control are discussed: deactivation of stimulants prior to action and biocontrol by Fusarium oxysporum. © 2016 Society of Chemical Industry  相似文献   

19.
The parasitic flowering plants of the genera Orobanche and Phelipanche (broomrape species) are obligatory chlorophyll-lacking root-parasitic weeds that infect dicotyledonous plants and cause heavy economic losses in a wide variety of plant species in warm-temperate and subtropical regions. One of the most effective strategies for broomrape control is crop breeding for broomrape resistance. Previous efforts to find natural broomrape-resistant tomato (Solanum lycopersicon) genotypes were unsuccessful, and no broomrape resistance was found in any wild tomato species. Recently, however, the fast-neutron-mutagenized tomato mutant SL-ORT1 was found to be highly resistant to various Phelipanche and Orobanche spp. Nevertheless, SL-ORT1 plants were parasitized by Phelipanche aegyptiaca if grown in pots together with the susceptible tomato cv. M-82. In the present study, no toxic activity or inhibition of Phelipanche seed germination could be detected in the SL-ORT1 root extracts. SL-ORT1 roots did not induce Phelipanche seed germination in pots but they were parasitized, at the same level as M-82, after application of the synthetic germination stimulant GR24 to the rhizosphere. Whereas liquid chromatography coupled to tandem mass spectrometry analysis of root exudates of M-82 revealed the presence of the strigolactones orobanchol, solanacol, and didehydro-orobanchol isomer, these compounds were not found in the exudates of SL-ORT1. It can be concluded that SL-ORT1 resistance results from its inability to produce and secrete natural germination stimulants to the rhizosphere.  相似文献   

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