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1.
H. D. Frinking E. G. A. Linders 《European journal of plant pathology / European Foundation for Plant Pathology》1986,92(3):97-106
The development of downy mildew (Peronospora farinosa) on a cultivated spinach crop (Spinacia oleracea) was compared to that on lambsquarters (Chenopodium album), a naturally occurring weed. Experiments were carried out on small spinach plots, in which epidemics could develop from point sources (PS) or area sources (AS).Two lambsquarter populations were studied, in which downy mildew epidemics arose from oospore infections. The downy mildew epidemics, on spinach and lambtquarters, were related to the environmental factors: temperature, vapour pressure deficit (VPD) and rainfall. It is concluded that the two different formae speciales ofP. farinosa, one on spinach and one on lambsquarters, react in the same way to weather changes. The epidemiological patterns were almost similar.Samenvatting De ontwikkeling van valse meeldauw (Peronospora farinosa) op het cultuurgewas spinazie (Spinacia oleracea) werd vergeleken met die op het zich natuurlijk ontwikkelende onkruid melganzevoet (Chenopodium album). Daarvoor werden experimenten uitgevoerd op spinazieperceeltjes, waarop in enkele gevallen puntbroninfecties (PS), en in andere gevallen oppervlaktebrondinfecties (AS) waren aangebracht. Er werd gevarieerd in inoculatietijdstip.Bij melganzevoet werden twee populaties bestudeerd, waarin de ziekte via oösporeinfectie op natuurlijke wijze was ontstaan.Het geheel werd in verband gebracht met de omgevingsfactoren: temperatuur, dampdruk-deficiet (VPD) en regenval. Geconcludeerd kan worden, dat deP. farinosa formae speciales zowel op spinazie als op melganzevoet op gelijke wijze reageerden op veranderingen in het weer. Het verloop van de epidemieeën was sterk vergelijkbaar. 相似文献
2.
Mamoru Satou Kazufumi Nishi Masaharu Kubota Michiko Fukami Hideaki Tsuji Kees van Ettekoven 《Journal of General Plant Pathology》2006,72(3):193-194
The races for the causal agent of spinach downy mildew Peronospora farinosa f. sp. spinaciae were identified by inoculation of race-differential cultivars. One isolate was identified as Pfs:5s and the others belonged
to a new race. This is the first report of race Pfs:5 and another new race in Japan. 相似文献
3.
Roy Kennedy Alison J. Wakeham 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(1):147-155
A monoclonal antibody that recognises components of the wall of sporangia of Peronospora destructor was raised. Tests using spores of higher fungi and other species of mildew demonstrated the specificity of the monoclonal.
The antibody was used to develop lateral flow devices for sporangia of P. destructor. A competitive lateral flow format was developed which could detect onion downy mildew sporangia. Five-microliter gold anti-mouse
IgM solution pre-mixed with 10 μl of P. destructor monoclonal antibody (EMA 242) proved the optimal concentration for detection of sporangia of P. destructor when applied to sample pads of lateral flow devices. Limits of approximately 500 sporangia of P. destructor could be detected by the absence of a test line on the lateral flow device within test samples. Using a scanning densitometer
improved the sensitivity of detection. Further development and validation of the test is required if it is to be used for
risk assessments of onion downy mildew in the field. 相似文献
4.
暗黑链霉菌PY-1活性产物分析及其对葡萄霜霉病田间防效评价 总被引：2，自引：0，他引：2
为探究暗黑链霉菌Streptomyces atratus PY-1对葡萄霜霉病菌Plasomopara viticola的抑制作用,通过扫描电镜观察PY-1发酵滤液对葡萄霜霉病菌孢子囊的影响,检测PY-1的活性物质种类,并测定其对葡萄霜霉病的田间防效。结果表明,PY-1发酵滤液能够导致葡萄霜霉病菌孢子囊和孢子囊梗出现褶皱、破裂和畸形,进而使其丧失侵染功能。PY-1菌株代谢产物中包含几丁质酶、蛋白酶、嗜铁素、1-氨基环丙烷-1-羧酸脱氨酶、氰化氢、吲哚乙酸,不含纤维素酶。PY-1菌株对葡萄霜霉病具有较好的田间防效,发酵原液对葡萄霜霉病的田间中期防效可达到89.17%以上,末期防效达86.28%以上,比52.5%噁唑菌酮·霜脲氰2 000倍液的防效略低,但显著高于58%甲霜·锰锌1 000倍液的防效;PY-1菌株发酵液稀释700倍后对葡萄霜霉病的末期防效与甲霜锰锌1 000倍液防效相当。表明PY-1菌株具有研制防治葡萄霜霉病生防制剂的潜力。 相似文献
5.
H. D. Frinking E. G. A. Linders 《European journal of plant pathology / European Foundation for Plant Pathology》1986,92(3):107-113
The development of downy mildew on spinach (Peronospora farinosa f. sp.spinaciae) was stratified according to leaf layers and represented in three-dimensional computer graphics, in which percentage diseased leaf area was plotted against time for each leaf layer. Distinction was made between a point source and an area source. Inoculations were made at three growth stages of the crop.More information could be gathered on the course of disease development on the upper leaf layers, for the first true leaf pair sporulates longer and more intensively, masking the disease development on the other leaf layers in this way.Samenvatting De ontwikkeling van valse meeldauw op spinazie (Peronospora farinosa f. sp.spinaciae) werd geanalyseerd aan de hand van drie-dimensionale grafische voorstellingen, waarbij percentage ziek bladoppervlak per bladetage werd uitgezet tegen tijd. Onderscheid werd gemaakt tussen de ontwikkeling vanuit een puntbron en vanuit een oppervlaktebron, bij inoculatie in drie groeistadia van het gewas.Het bleek dat hierbij meer informatie kon worden verkregen over het verloop van de ziekte-ontwikkeling op de bovenste bladetages, omdat het eerste echte bladpaar langduriger en heviger sporuleert, en zo de ziekte-ontwikkeling op de overige bladetages maskeert. 相似文献
6.
Occurrence and molecular characterization of azoxystrobin resistance in cucumber downy mildew in Shandong province of China 总被引：1，自引：0，他引：1
Cucumber downy mildew caused byPseudoperonospora cubensis (Berk. and Curt.) Rostov. limits crop production in Shandong Province of China. Since management of downy mildew is strongly
dependent on fungicides, a rational design of control programs requires a good understanding of the fungicide resistance phenomenon
in field populations of the pathogen. A total of 106 and 97 isolates ofP. cubensis were obtained in 2006 and 2007, respectively. The EC50 values for the growth of all the 106 isolates collected in 2006 were 0.0063–0.0688μg ml−1 (average: 0.0196±0.0048μg ml−1) azoxystrobin and these were therefore considered sensitive isolates. However, 57 field isolates ofP. cubensis of the 97 collected in 2007 with EC50 values that ranged from 0.609 to >51.2μg ml−1 were considered resistant to azoxystrobin. Fragments of the fungicide-targeted mitochondrial cytochromeb gene from total pathogen DNA were amplified using polymerase chain reaction and their sequences analyzed to elucidate the
molecular mechanism of resistance. A single point mutation (GGT to GCT) in the cytochromeb gene, resulting in substitution of glycine by alanine at position 143, was found in the three selected azoxystrobin-resistant
isolates of downy mildew. This substitution in cytochromeb exhibited different resistance levels, with the resistance factor from 21.15 to greater than 2618.9. In addition, the different
resistance levels seemed to appear within 1 year (between 2006 and 2007). Therefore, growers of Shandong Province in China
now are faced with a challenge in managing the azoxystrobin resistance in cucumber downy mildew.
http://www.phytoparasitica.org posting March 10, 2008. 相似文献
7.
Saïd Mouzeyar Felicity Vear Denis Tourvieille de Labrouhe 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(4):399-404
The mode of action of the fungicide metalaxyl againstPlasmopara halstedii, the causal agent of sunflower downy mildew, was studied following its application before, during and after artificial contamination of seedlings. The development of the fungus within the treated seedlings was examined microscopically and compared to that occuring in untreated genetically susceptible or resistant genotypes. Hypersensitive-like reactions and necrotic zones leading to the inhibition of fungus growth within the hypocotyl were observed for the three modes of application. This suggests that sunflower defence mechanisms activated by genetical resistance are also involved in the control of downy mildew by metalaxyl. 相似文献
8.
葡萄叶提取物对葡萄霜霉病的防治作用及有效成分分析 总被引：1，自引：0，他引：1
为探究葡萄叶提取物对葡萄霜霉病的防治作用,测定了葡萄叶提取物及其有效物质对葡萄生单轴霉Plasmopara viticola孢子囊和游动孢子的抑制作用以及对葡萄霜霉病的防治效果,观察了其对葡萄生单轴霉在叶片中扩展、产生孢子囊能力的影响,并对葡萄叶提取物组成成分进行了分析。结果表明,葡萄叶提取物对葡萄生单轴霉孢子囊的形成和萌发均有明显的抑制作用。当葡萄叶提取物浓度为10 mg/mL时,其对孢子囊形成的抑制率为82.4%,葡萄生单轴霉孢子囊和游动孢子的萌发率仅为7.6%和1.1%,均显著低于无菌水处理。荧光显微观察发现,葡萄叶提取物可以抑制葡萄生单轴霉在叶片内的扩展。当葡萄叶提取物浓度为10 mg/mL和50 mg/mL时,对葡萄霜霉病的室内防治效果分别为80.1%和100.0%;且浓度为10 mg/mL的葡萄叶提取物对葡萄霜霉病的田间预防效果为67.8%,与烯酰吗啉处理无显著差异。液质联用技术检测显示,葡萄叶提取物中含有白藜芦醇和紫檀芪,其对葡萄生单轴霉均有显著的抑制作用,且紫檀芪的抑制效果强于白藜芦醇。 相似文献
9.
Mamoru SATOU Takuma SUGIURA Ryuki OHSAKI Noriyuki HONDA Seizo HORIUCHI Norihito YAMAUCHI 《Journal of General Plant Pathology》2002,68(1):49-51
A new race of spinach downy mildew caused by Peronospora effusa occurred in Fukui, Japan. The fungus was capable of affecting spinach cultivars resistant to races 1, 2, 3 and 4, but not
some other cultivars. Thus, the fungus had different pathogenicity from race 3 and race 4 of the pathogen and was considered
to be a new race of spinach downy mildew in Japan.
Received 26 April 2001/ Accepted in revised form 17 August 2001 相似文献
10.
为明确樟树枝叶提取物对葡萄霜霉病的防治效果,采用混合液滴显微镜观察法研究了樟树枝叶提取物及其活性成分对病原菌孢子囊萌发的抑制作用,利用高效液相色谱法鉴定了枝叶乙酸乙酯萃取物的化学成分,测定了其活性成分对葡萄霜霉病的室内和田间防治效果。结果表明,浓度为0.1 g/mL以上的樟树枝叶提取物对孢子囊萌发均有很好的抑制效果,抑制率达100.0%;樟树枝叶提取物经不同极性有机溶剂萃取后,分别获得正己烷、乙酸乙酯、正丁醇和水相分离物,浓度为1.0%时各分离物对孢子囊萌发的抑制率分别为58.4%、92.4%、32.5%和58.7%,乙酸乙酯相富集了主要抑菌活性成分,经液相色谱分析并与色谱库数据比对,确定其活性成分中含有芦丁和槲皮素;浓度为1.0%的芦丁和槲皮素对孢子囊具有抑制作用;田间试验显示,浓度为0.3 g/mL以上的枝叶提取物对葡萄霜霉病预防效果显著,治疗效果在60.0%以上。研究表明,樟树枝叶提取物可以有效控制葡萄霜霉病,提取物的活性成分芦丁和槲皮素可以作为植物源药剂。 相似文献
11.
枯草芽胞杆菌HMB-20428与化学杀菌剂互作对葡萄霜霉病菌抑制作用和替代部分化学药剂减量用药应用 总被引：1，自引：0，他引：1
为明确生防菌剂枯草芽胞杆菌Bacillus subtilis HMB-20428与化学杀菌剂互作对葡萄霜霉病菌Plasmopara viticola的抑制作用,采用生物测定与田间药效试验研究其最佳用药时期,筛选最佳生化互作组合,结合空间竞争能力和诱导抗病性生理测定试验了解互作增效机制,并建立葡萄霜霉病的综合防控技术。结果显示,枯草芽胞杆菌HMB-20428预防葡萄霜霉病最佳时期为发病前1个月,连续喷雾用药3~4次,间隔期10~15 d。研发出协同增效生化互作组合生防菌剂HMB-20428+嘧菌酯,及其与硅氧烷化合物增效组合,防效分别为91.06%~98.92%和87.78%~92.04%。枯草芽胞杆菌HMB-20428与嘧菌酯互作可增强枯草芽胞杆菌HMB-20428定殖能力和植株抗病作用,且定殖能力和抗病机制作用的增强时间基本一致。以生防菌剂HMB-20428替代部分化学药剂减量用药流程的防效为91.40%。表明枯草芽胞杆菌HMB-20428与嘧菌酯互作可达到减少化学药剂用量的目的。 相似文献
12.
S. Friedrich G.M.E. Leinhos F.-J. Löpmeier 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(1):35-45
The weather-based forecasting model ZWIPERO was developed by the German Weather Service and determines the risk of sporulation and infection of Peronospora destructor quantitatively based on actual as well as predicted weather data (temperature, relative humidity, leaf wetness, precipitation). The model allows precise planning of disease monitoring and infection-related application of fungicides. ZWIPERO is a more complex mathematical model than the previously published models for downy mildew. In order to operate ZWIPERO independently of the actual field location and season, the time of sunrise and sunset of the location are exactly determined by a subroutine. Another subroutine provides simulated microclimatic input variables based on local production data as well as actual and hourly predicted (up to 4 days) standard weather data. Starting at the time of 'sunrise + 7 h', ZWIPERO calculates the number of sporangia produced, the time of onset of sporangia release, as well as the number of infections possible and the number of sporangia which may survive the day for each 24-h time step. Field evaluations of sporulation periods of downy mildew showed that the simulated micrometeorological input variables are reliable. As the actual plant development, the susceptibility and the disease incidence in the field are not taken into account, ZWIPERO has to be considered primarily as a decision support system for extension services and growers. 相似文献
13.
Hedvig Komjáti Ilona Walcz Ferenc Virányi Reinhard Zipper Marco Thines Otmar Spring 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(4):421-428
Leaves of Xanthium strumarium infected with downy mildew were collected in the vicinity of a sunflower field in southern Hungary in 2003. Based on phenotypic
characteristics of sporangiophores, sporangia and oospores as well as host preference the pathogen was classified as Plasmopara angustiterminalis. Additional phenotypic characters were investigated such as the size of sporangia, the number of zoospores per sporangium
and the time-course of their release. Infection studies revealed infectivity of the P. angustiterminalis isolate to both X. strumarium and Helianthus annuus. Inoculation of the sunflower inbred line, HA-335 with resistance to all known P. halstedii pathotypes, resulted in profuse sporulation on cotyledons and formation of oospores in the bases of hypocotyls. Infections
of sunflower differential lines often led to damping-off. Molecular genetic analysis using simple sequence repeat primers
and nuclear rDNA sequences revealed clear differences to Plasmopara halstedii, the downy mildew pathogen of sunflower. 相似文献
14.
Peronospora salviae-officinalis, the causal agent of downy mildew on common sage, is an obligate biotrophic pathogen. It grows in the intercellular spaces of the leaf tissue of sage and forms intracellular haustoria to interface with host cells. Although P. salviae-officinalis was described as a species of its own 10 years ago, the infection process remains obscure. To address this, a histological study of various infection events, from the adhesion of conidia on the leaf surface to de novo sporulation is presented here. As histological studies of oomycetes are challenging due to the lack of chitin in their cell wall, we also present an improved method for staining downy mildews for confocal laser scanning microscopy as well as evaluating the potential of autofluorescence of fixed nonstained samples. For staining, a 1:1 mixture of aniline blue and trypan blue was found most suitable and was used for staining of oomycete and plant structures, allowing discrimination between them as well as the visualization of plant immune responses. The method was also used to examine samples of Peronospora lamii on Lamium purpureum and Peronospora belbahrii on Ocimum basilicum, demonstrating the potential of the presented histological method for studying the infection processes of downy mildews in general. 相似文献
15.
葡萄生单轴霉重寄生菌F3的鉴定及防治效果测定 总被引：1，自引：0，他引：1
为明确从生长异常的葡萄霜霉层上分离获得的菌株F3对葡萄生单轴霉Plasmopara viticola的重寄生作用及对葡萄霜霉病的防治效果,通过光学和扫描电子显微镜观察菌株F3对葡萄生单轴霉的重寄生作用,并对菌株F3进行形态特征观察及28S rDNA序列分析,采用孢子囊萌发抑制和离体叶片点样法测定该菌株对葡萄霜霉病的防治效果。结果表明,菌株F3对葡萄生单轴霉表现出覆盖、缠绕的重寄生现象。结合形态特征与序列分析结果将该菌株最终鉴定为层生镰刀菌Fusarium proliferatum。菌株F3分生孢子悬浮液及其无菌发酵液对葡萄霜霉菌孢子囊萌发具有显著的抑制作用,抑制率分别为86.8%和83.1%;经菌株F3分生孢子悬浮液预防处理后的离体葡萄叶片发病率为10.9%,显著低于对照的发病率98.8%,防治效果达88.9%;菌株F3分生孢子悬浮液与葡萄霜霉病菌孢子囊混合后点样接种处理的叶片发病率为50.0%,也显著低于对照,防治效果为49.1%;而治疗处理的叶片发病率与对照间无显著差异。表明层生镰刀菌对葡萄生单轴霉具有重寄生作用,且对葡萄霜霉病具有较强的预防控制作用。 相似文献
16.
Spray mixtures consisting of the plant activator BABA (DL-3-aminobutyric acid) and the protectant fungicide mancozeb were
significantly more effective than BABA or mancozeb alone in controlling late blight (Phytophthora infestans) in potato and tomato and downy mildew (Pseudoperonospora cubensis) in cucumber. A mixture composed of 5 parts BABA and 1 part mancozeb (w/w, a.i.) exhibited a higher synergy factor than the
1+1 or the 1+5 (BABA + mancozeb) mixtures. No synergistic interaction was detected between BABA plus mancozeb in controlling
sporangial or cystospore germination, nor mycelial growth ofP. infestans in vitro. The results showed enhanced effect of mancozeb in BABA-induced plants, suggesting, therefore, that lower dosages of this
fungicide may be sufficient to control late blight or downy mildew under field conditions.
http://www.phytoparasitica.org posting July 15, 2003. 相似文献
17.
J. Palti 《Phytoparasitica》1989,17(1):31-48
The effect of environmental factors on the development of each stage ofPeronospora destructor (Berk.) Caspary on onions is reviewed. For sporulation to take place, a period of light must precede the period of darkness
and high humidity in which spores are formed. Spores are discharged when the relative humidity (RH) is increasing or decreasing,
and over a wide range of temperatures. Their discharge is triggered by exposure to red-infrared radiation and by vibration
of the leaf. Dissemination of spores follows a daily periodic cycle and spores can be blown by wind over long distances. Duration
of spore survival depends on temperature, RH and, especially, the absence of strong radiation.
The rate of spore germination is highest at 10°C and declines with the rise in temperature. Germ tubes develop in liquid water,
and a continuous period of wetness is required for infection to be completed. Systemic infection is common in cooler climates,
where necks of onion bulbs are slow to dry. The principal sources of downy mildew infection by wind-borne spores are systemically
infected propagation material, onion volunteer plants, and neighboring older crops. 相似文献
18.
Shantharaj Deepak Sathyanarayana Niranjan-Raj Shekar Shailasree Ramachandra K. Kini Wilhelm Boland Hunthrike S. Shetty Axel Mithfer 《Physiological and Molecular Plant Pathology》2007,71(1-3):96-105
The synthetic 1-oxo-indanoyl-l-isoleucine methyl ester (Ind-Ile-Me) represents a highly active mimic of octadecanoic phytohormones, which are involved in plant defenses against pathogens and pests. Seed treatments and foliar spray with Ind-Ile-Me were tested for induced resistance against downy mildew disease caused by the phytopathogenic oomycete Sclerospora graminicola in pearl millet (Pennisetum glaucum) under greenhouse and field conditions. Under greenhouse conditions, a 50% protection level was achieved after seed treatment. Seed treatment in combination with foliar spray resulted in 60% protection. The induction of resistance was correlated with the enhanced activities of defense-related proteins such as phenylalanine-ammonia-lyase, peroxidase, and enhanced level of hydroxyproline-rich glycoproteins. Under field conditions, a maximum protection of 62% was recorded upon seed treatment along with foliar spray. Hence, it infers that Ind-Ile-Me can be used as a valuable protection compound at least in downy mildew disease management. 相似文献
19.
20.
Barbara Thuerig Andres Binder Thomas Boller Urs Guyer Sonia Jiménez Christina Rentsch Lucius Tamm 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(2):185-197
We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field
conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion from downy mildew (Peronospora destructor) and apple trees from apple scab (caused by Venturia inaequalis) to a similar extent as fungicides such as copper and sulphur or well-known inducers such as benzothiadiazole or β-aminobutyric
acid. Pen had no major direct fungicidal effect and is thus supposed to protect plants by activating their defense mechanisms.
The raw material for extraction of Pen was available in constant quality, a prerequisite for commercial application. Under
certain conditions, Pen caused phytotoxic side effects. The symptoms mostly consisted of small necrotic spots or, more rarely,
of larger necrotic areas. The development of the symptoms was dependent on several parameters, including concentration of
Pen, the number of applications, the persistence on the plant tissue, the plant species and variety and environmental conditions.
In grapevine, a partially purified fraction of Pen was much less toxic than the crude Pen extract, but protected the plants
to a similar extent against P. viticola. Our data show that Pen has interesting and unique properties as a plant protection agent, but more research is needed to
further reduce its phytotoxic side effects. 相似文献