共查询到20条相似文献，搜索用时 31 毫秒
1.
D. Pilarska M. McManus A. E. Hajek F. Herard F. E. Vega P. Pilarski G. Markova 《Anzeiger für Sch?dlingskunde》2000,73(5):125-126
The entomopathogenic fungusEntomophaga maimaiga was introduced into aL. dispar population situated in South Bulgaria for the first time in Europe.
It was found that of all larvae collected in the five experimental plots, 6.3 % contained conidia and resting spores ofE. maimaiga, 14.2 % contained parasitoids and 2.3 % were infected with nucleopolyhedrovirus (NPV). The presence of the fungus in cadavers
collected from each experimental plots and on five of the six collection dates was observed. 相似文献
2.
Georgi Georgiev Zdravko Hubenov Margarita Georgieva Plamen Mirchev Maria Matova Leellen F. Solter Daniela Pilarska Plamen Pilarski 《Phytoparasitica》2013,41(2):125-131
Interactions between the gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae), pathogenic fungus Entomophaga maimaiga, and the tachinid parasitoid (Diptera: Tachinidae) complex in gypsy moth larvae were investigated in Bulgaria, where E. maimaiga was recently released as a biological control agent. Gypsy moth larvae were collected in oak stands where E. maimaiga was originally introduced (nine sites) and in sites where the pathogen has invaded by natural extension of the range (ten sites). In total, 4,375 host larvae were examined and 401 tachinid larvae emerged from parasitized hosts. Host mortality caused by tachinids varied from 0 to 48.5% among sites, with an overall average of 9.2%. Emerging adult tachinid parasitoids included 54 individuals belonging to six species: Compsilura concinnata, Exorista larvarum, Senometopia separata, Senometopia excisa, Drino incospiqua and Zenilia libatrix; the remaining parasitoids (86.5%) died in the pupal stage. E. maimaiga azygospores were observed on puparia surfaces, an indication that the gypsy moth host larvae were infected with the fungus. No azygospores were observed in parasitoid tissues. The high parasitoid mortality may be the result of the competition with E. maimaiga during development in the same host. 相似文献
3.
Assumpció Batlle M. Angeles Martínez Amparo Laviña 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(9):811-816
The main viticultural production areas in Spain were surveyed in 1994, 1995 and 1996 for the occurrence and incidence of Grapevine Yellows diseases associated to phytoplasmas. Samples from 300 plants showing symptoms of phytoplasma infection were collected from grapevine fields in the Spanish regions of Aragón, Catalonia and Navarra and analysed by PCR with specific primers for a non-ribosomal DNA of stolbur/Bois Noir (BN) and of Flavescence dorée (FD) phytoplasma. Nested PCR with universal primers P1/P7 and fU5/rU3 was also used. In the survey conducted in 1994 and 1995 only BN/stolbur phytoplasma was detected. The incidence of symptomatic plants was low in five plots of Catalonia from 3% to 18% in 1994 and 1995, respectively, and high in two plots of Navarra, from 60% to 80%. In the survey conducted in 1996 the incidence of symptomatic plants in Catalonia increased (6–80%) due to the presence of FD in five plots in the Northeastern Catalonia. An epidemiological study was carried out in two BN-affected plots of two regions from 1994 to 1997, with the evaluation of potential vectors and of host plants. The stolbur phytoplasma was found in individuals from different insect species belonging to the families Cicadellidae and Delphacidae. Some wild plants naturally infected with stolbur phytoplasma around the infected grapevines were: Convolvulus arvensis, Lavandula officinalis, Polygonum convolvulus, Solanum nigrum, and Thymus officinalis. The incidence of the disease in one BN-infected grapevine plot increased from 3.4% in 1994 to 18.40% in 1997. 相似文献
4.
The effectiveness of old and new strategies for the long‐term control of Pteridium aquilinum,an 8‐year test 
下载免费PDF全文
下载免费PDF全文 G Milligan E S Cox J G Alday V M Santana H A McAllister R J Pakeman M G Le Duc R H Marrs 《Weed Research》2016,56(3):247-257
There is a need for management strategies to control dominant perennial weeds and restore seminatural communities. We compared the effects of five weed control treatments on dense Pteridium aquilinum relative to an untreated experimental control over an 8‐year period with the aim of restoring acid grassland. The weed control treatments tested were as follows: cutting and bruising, both twice and thrice annually, and herbicide treatment (asulam in year 1 followed by annual spot retreatment of all emergent fronds). Pteridium aquilinum performance and plant species composition were monitored. Data were analysed using Bayesian mixed‐effect models and multivariate techniques. Cutting twice and thrice yearly and the asulam treatment all reduced frond density to zero; both bruising treatments were ineffective. The plant communities in the cut and asulam‐treated plots showed differences from the untreated and bruised plots; the asulam‐treated plots contained more ruderal species and the cut plots were more typical of acid grassland. Acid grassland recovery was fastest in the asulam‐treated plots, but the cut plots caught up after approximately 5 years. There were two important conclusions. First, an intractable weed like P. aquilinum can be eradicated and a vegetation more suited for grazing can be achieved by the continuous application of some treatments over many years. Here, success was achieved by cutting twice/thrice annually, or by a single asulam application followed by annual spot spraying of all emergent fronds for 8 years. Second, bruising, a treatment favoured by some conservation organisations, did not work and cannot be recommended. The use of long‐term, continuously applied treatments might be considered for all perennial weeds with large underground root/rhizome systems. 相似文献
5.
Fluazifop-butyl, haloxyfop and sethoxydim with adjuvant oil were applied for three successive growing seasons to established strawberries infested with Elymus repens. The weed was virtually eradicated by three applications of haloxyfop (0.8 kg a.e. ha?1) in successive years. A similar effect was given by five applications of haloxyfop (0.4 kg a.e. ha?1) and fluazifop-butyl (1.6 kg AI ha?1) in three growing seasons. Lower rates of haloxyfop and fluazifop-butyl, and a high rate of sethoxydim (1.6 kg AI ha?1) applied five times were less effective, the ground cover of E. repens shoots not being reduced by the end of the experiment although weight of living rhizome was only 10-30% of that on untreated plots. Fruit yields on treated plots generally reflected the level of E. repens control, but there was some evidence of crop phytotoxicity from herbicide treatments. During the experiment E. repens untreated plots increased from about 30-100% ground cover and reduced yield 13, 28 and 68% in successive years compared with weed-free plots. 相似文献
6.
Ko-ichi OSHIMAN 《Journal of General Plant Pathology》2000,66(3):258-263
Pretreatment with sodium alginate (20 g/m2) prior to application of a biocontrol agent, Pseudomonas fluorescens strain A11RN, enhanced the control turfgrass snow mold caused by Typhula ishikariensis biotype B. Disease severities in two fields relative to untreated control plots were 53% and 61% in plots treated with both
the strain and sodium alginate, which were significantly lower than 69% and 77% in plots treated only with the strain. The
antagonist population remained above the threshold for effective control (ca. 1×107 cfu/cm3) at least for the first month under snow in pretreatment with sodium alginate. The population of the biocontrol agent after
snowmelt on turfgrass was five times higher in sodium alginate-amended plots than in unamended plots. Sodium alginate alone
did not reduce disease severity. Sodium alginate might have supported the survival of the applied strain.
Received 7 June 1999/ Accepted in revised form 20 December 1999 相似文献
7.
为明确内蒙古自治区阴山北麓地区向日葵小核盘菌Sclerotinia minor的遗传变异,对自内蒙古自治区乌兰察布市、包头市和呼和浩特市向日葵上分离纯化的110株向日葵小核盘菌菌株进行菌丝亲和组(mycelium compatibility group,MCG)划分,并对5个主要MCG组间和组内各菌株的生物学特性、致病力和交配型进行测定。结果表明,供试的110株菌株被划分为14个亲合组,其中MCG1为主要类型,包含32株菌株,占总菌株的29.1%;MCG2包含来自7个地点的25株菌株;5个MCG仅包含1株菌株;在这14个MCG中,MCG1～MCG5包含92株菌株,占总菌株数的83.6%。MCG1～MCG5组间各菌株在菌落直径和草酸分泌量上存在差异,但在菌核形成量、多聚半乳糖醛酸酶活性和致病力上无显著差异;而MCG1～MCG5组内各菌株在菌落直径、草酸分泌量、菌核形成量、多聚半乳糖醛酸酶活性和致病力上均有一定差异。在MCG1～MCG5各菌株的交配型中,除MCG2中菌株的负反转型与正反转型比例接近1∶1外,其它4个MCG中菌株的负反转型与正反转型比例均偏离1∶1,表明内蒙古自治区向日葵小核盘菌具有较高的遗传变异程度。 相似文献
8.
9.
为明确中国61个小麦后备品种对白粉病的抗性水平及其抗病基因,将2016年从黄淮海冬麦区、长江中下游冬麦区及东北春麦区的9个市采集分离的269株单孢子堆白粉病菌,分别接种于61个小麦后备品种进行抗性测定;用NTSYSpc 2.10e软件对供试品种表型数据进行聚类分析;用35株鉴别菌株对29个含已知抗白粉病基因小麦材料和61个小麦后备品种进行鉴别,比较其抗谱并推导61个小麦后备品种所含抗白粉病基因。结果显示,61个小麦后备品种间的抗谱存在明显差异,国豪麦5号和7号、BL5008、绵麦系列、黔麦系列、楚麦16号、内麦101和366等18个品种抗谱较宽,抗性频率均大于97.0%;泰科麦5303、邯11-5272和临Y8222等10个品种的抗性频率在42.0%～56.1%之间;郑麦0943等33个品种的抗性频率小于37.9%。聚类分析可将61个小麦后备品种分成5大类,第I类有11个品种,其中8个品种的抗性频率在42.0%～56.1%之间;第II类和第III类共30个品种,抗性频率均小于32.7%;第IV类有2个品种,抗性频率分别为53.5%和53.2%,第V类有18个品种,抗性频率均大于97.0%;聚类显示来自于同一地区且抗性频率相近的品种具有相似或相近的抗性遗传背景。本研究推导出21个小麦后备品种含抗病Pm基因,其中,邯11-5272含有Pm30,安科1503含有Pm2、Pm5a、Pm6、Pm19和Pm30,临Y8222含有Pm5a、Pm6、Pm19和Pm30,云154-15含有Pm5a、Pm6、Pm7、Pm19和Pm2+ta,泰科麦5303等6个品种含有Pm2和Pm30,华麦7号等5个品种含有Pm5a、Pm6和Pm19,扬麦24号等6个品种含有Pm5a、Pm6、Pm19和Pm2+ta。研究表明,54.1%的小麦后备品种对白粉病菌群的抗性频率小于37.9%,存在适宜条件下小麦白粉病暴发流行的风险,因此这些小麦后备品种推广种植时需加强病害预警和监测。 相似文献
10.
11.
Pedro Boff Pieter Kastelein Joop de Kraker Matthijs Gerlagh Jürgen Köhl 《European journal of plant pathology / European Foundation for Plant Pathology》2001,107(6):615-624
The epidemiology of Botrytis cinerea was studied in five annual strawberry crops using waiting-bed transplants, a system widely adopted in the Netherlands. On dead leaves of transplants the incidence of B. cinerea varied from 26.7% to 52.6%, but the leaf area with potential sporulation was low (3.5–15.6%). During each crop cycle, the availability of necrotic leaf substrate for spore production of B. cinerea was generally low and varied between seasons and with the quality of transplants. B. cinerea sporulated on a maximum of 15.5 cm2 of leaf area per plant, measured as potential sporulation. The aerial concentration of B. cinerea conidia in untreated plots did not differ from the concentration in plots where all dead leaves had been removed, nor from the concentration at 25–50 m distance from the strawberry plots. B. cinerea incidence on flowers ranged from 5% to 96%, but no correlation was found with the potential spore production on necrotic leaves. Grey mould at harvest varied from 1.4% to 11.3% and was correlated with the average precipitation during the harvesting period but not with B. cinerea incidence on flowers. Post-harvest grey mould ranged from 2.1% to 32.6% and was correlated with petal colonisation by B. cinerea. The results suggest that in the annual cropping system with waiting-bed transplants, necrotic leaves are not a significant source of B. cinerea inoculum, unlike in other strawberry production systems. Therefore, control measures of grey mould in this annual system should focus on protection of flowers and young developing fruits, and not on the reduction of inoculum production on leaf debris. 相似文献
12.
A three-year field study was conducted using twelve 7.4×3.7 m plots and simulated rainfall to investigate pesticide run-off following application to a golf course fairway. The plots were sprigged with ‘Tifway 419’ bermudagrass (Cynodon dactylon×C transvaalensis). The dimethylamine salt of 2,4-D [(2,4-dichlorophenoxy)acetic acid] was applied as foliar sprays at a rate of 2.24 kg AI ha−1. Simulated rainfall was applied at an intensity of 29 mm h−1 one day before and 1, 2, 4, and 8 days after the pesticide applications for 0.92, 1.75. 1.75, 0.92, and 0.92 h, respectively. Water run-off was measured using a tipping-bucket apparatus and sub-samples were analyzed for pesticide residues. Data collected from the study were also compared with the GLEAMS and PRZM-2 model simulations for surface water and 2,4-D run-off. Mass and concentration of 2,4-D in run-off decreased rapidly, with 74.5% of the total run-off of 2,4-D occurring in the first run-off event after treatment. When calibrated to the site-specific characteristics, the GLEAMS and the PRZM-2 models adequately simulated the average of surface water run-off over all plots, with normalized root mean square error (NRMSE) and coefficient of determination for linear regression (R2) being 22.8% and 0.917 for GLEAMS, and 23.7% and 0.879 for PRZM-2, respectively. However, both GLEAMS (NRMSE=82.1%, R2=0.776) and PRZM-2 (NRMSE=125.8%, R2=0.513) less accurately simulated 2,4-D concentrations in run-off. © 1999 Society of Chemical Industry 相似文献
13.
Narrow-leaved hawk's-beard (Crevis tectorum L.) occurs in all provinces of Canada, but is particularly abundant in the northern portions of the agricultural regions of the three prairie provinces and British Columbia. The losses in yield in terms of quantity and quality due to narrow-leaved hawk's-beard were investigated in fields of lucerne (Medicago sativa L.) used in the dehydration industry and in experimental plots. The effect of hawk's-beard on creeping red fescue (Festuca rubra L.) seed yield in the Peace River Region of British Columbia was also investigated. In the lucerne, the average percentage of hawk's-beard in the total biomass over the 3 years of the study was only 2?5%, with a minimum of 1?2% in one year and a maximum of 5?5% in another year. In the lucerne vs hawk's-beard plots, yields on plots free of hawk's-beard were not significantly higher than on those with hawks'-beard. Although excellent control was achieved in creeping red fescue (Festuca rubra L.) by the use of the herbicide 2, 4-DB, yields of seed were not significantly increased. Therefore, narrow-leaved hawk's-beard seems to be an excellent colonizer but a weak competitor and contributed little to crop losses in lucerne and creeping red fescue. 相似文献
14.
Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae) is a major pest of oilseed rape in Europe and North America. The last decade has seen growing interest in the occurrence, importance and efficiacy of its parasitoids as biocontrol agents. The infestation of pods by C. obstrictus larvae and their parasitism rates were assessed in a total of nine commercially-grown crops and fifteen experimental plots of winter oilseed rape in 2004–2007. Pod samples were collected at the pod maturation stage and incubated in emergence traps. Emerged larvae, their exit holes and parasitoids were counted and identified; the percentage of infested pods and parasitism rates were calculated. Pod infestation by larvae increased continuously over the study period. The parasitism level was lowest in 2005 and increased thereafter up to 96%. The most abundant parasitoid was Trichomalus perfectus (Walker), but Mesopolobus morys (Walker) and Stenomalina gracilis (Walker) (Hymenoptera: Pteromalidae) were also reared from host larvae. This study showed that naturally-occurring ectoparasitoids of C. obstrictus were capable of becoming established as viable populations and have the potential to contribute to biological control of C. obstrictus. 相似文献
15.
L. Benjamini 《Phytoparasitica》1981,9(2):89-94
Temik, the granular formulation of aldicarb [2-methyl-2(methylthio) propionaldehyde 0-(methylcarbamoyl) oxime], was placed together with sugar beet seeds during sowing along the rows, at a rate of 1.4 g/m, in a 1.5-ha experimental area within a 6-ha sugar beet field in an arid area with a long history of bird damage. Thirty-three chukar partridges, a major pest of sprouting crops, were observed foraging in the experimental area throughout the 4-week period between sowing and assessment of damage. Damage was restricted to the borders of the field, with a significant difference in level of damage between treated and control plots located along the borders; the size of damaged areas was about five times smaller in the treated plots than in the control plots. The results were interpreted as reflecting the repellent effect of aldicarb absorbed by the sprouts, and as establishment of a conditioned aversion by the chukars to sugar beet sprouts. The high toxicity of the treated sprouts was demonstrated when adult Japanese quail were fed sprouts collected from treated plots. 相似文献
16.
Standing water from carbofuran-treated Azolla plots showing accelerated degradation was further enriched by five repeated transfers to carbofuran-supplemented mineral salts medium. This enrichment culture developed from standing water of carbofuran-treated Azolla plot can utilise carbofuran as sole source of carbon and nitrogen. The enrichment culture was able to hydrolyse nearly 100% of [ring-14C]carbofuran to carbofuran phenol in five days, which accumulated in the medium, while the carbamate side-chain in [carbonyl-14C]carbofuran was readily mineralized to [14C]carbon dioxide. Enrichment culture was able to degrade carbofuran up to 1000 µg ml−1 levels in mineral salts medium with ease. © 1999 Society of Chemical Industry 相似文献
17.
Whitefly infestations and parasitism were monitored year-round in overlapping cotton crops sown on three dates in Burkina Faso. The relative abundance of B. tabaci (Gennadius) and its parasitoids, Eretmocerus spp. and Encarsia spp., was recorded in control and insecticide-sprayed plots. Low B. tabaci populations developed during the first half of the rainy season. Pest populations increased when rainfall was ending, and the levels reached were higher in insecticide-treated plots (48 nymphs/leaf) than in control plots (25 nymphs/leaf). Parasitism reached 88.7% in control plots, and 53.7% in insecticide-treated plots. Eretmocerus spp. nymphs were more abundant than Encarsia spp. in both treated and control plots. A positive and significant curvilinear relationship was observed where % parasitism, on a linear scale, rose to a plateau with logarithmic increase in host density. In general % parasitism was correlated with the abundance of pest populations except in March and April where parasitism increased while B. tabaci populations decreased. In a separate experiment, adult Eretmocerus spp. were released into caged cotton plants to study the impact of augmentative releases of the parasites on the population dynamics of the pest. Pest densities increased from 1.47 nymphs/leaf to 39.4 nymphs/leaf in the control, but were reduced to 0.8 and 0.6 nymphs/leaf in the cages where, respectively, 4 and 8 parasitoids were released per plant. It appears that parasitism is an important factor reducing B. tabaci populations during and after the cotton-growing season, and that Eretmocerus spp. are promising biological control candidates against the pest in cotton. 相似文献
18.
Factors involved in the establishment of Taraxacum officinale (dandelion) seedlings in grasslands and plant mortality in the first growing season were studied during 2008–2011. The study was conducted at 11 grassland sites that differed in the quantity of seed rain and the intensity of seedling predation by slugs. In April, of each study year, 10 plots open to the sedimentation of naturally dispersed seeds were established at each site, five plots of which were also sown with 250 T. officinale seeds each. The amount of natural seed rain, slug feeding activity and number of plants in each plot were then recorded at monthly intervals. Seed rain and seedling predation accounted for c. 50% of the variation in seedling establishment. Populations of established seedlings then declined through October, at which point they were at 25% of the original abundance on average. The percentage of plants that survived varied among sites and years. The temporal and spatial variation in T. officinale establishment and survival of young plants was enormous, even within a small area. Predation of seedlings by slugs can effectively prevent the establishment of T. officinale in grassland. This only occurred, however, at slug abundances not acceptable under conditions of public access. 相似文献
19.
Field experiments were conducted during 1997 and 1998 to determine the effects of sugar beet cultivar susceptibility to Cercospora
leaf-spot on the sensitivity ofCercospora beticola isolates to the triazole fungicide flutriafol. Four cultivars with different levels of disease resistance were treated in
experimental plots with six spray applications of flutriafol. Disease assessments were carried out at 15-day intervals. Sensitivity
to flutriafol was measured on isolates collected from the plots ∼15 days after the last flutriafol application. Measurements
of disease severity and calculations of AUDPC (area under disease progress curve) values showed a distinct differentiation
among cultivars, reflecting their level of disease resistance. Disease severity was significantly lower in cvs. ‘Bianca’ and
‘Areth’ than in ‘Univers’ and ‘Rizor’ both in the untreated and in the flutriafol-treated plots. Fungal isolates from flutriafol-treated
plots were less sensitive to the fungicide than were isolates from untreated plots. However, no differences in isolate sensitivity
were observed among the cultivars, as regards their level of disease resistance. Despite the fact that the use of resistant
cultivars cannot eliminate selectively the resistant strains, it can eliminate both resistant and sensitive isolates. Reducing
the number of treatments with DMIs, by applying them only when environmental conditions are favorable for disease development,
is a prerequisite for successful resistance management; therefore, the use of disease-resistant varieties could aid toward
management of DMIs resistance inC. beticola.
http://www.phytoparasitica.org posting May 6, 2003. 相似文献
20.
基于SSR序列的江西省不同生态地区稻瘟病菌遗传多样性分析 总被引：1，自引：1，他引：0
为明确江西省稻瘟病菌Magnaporthe oryzae群体遗传结构及其多样性水平,选用13对SSR引物对分离自5个不同生态地理县(市)水稻穗颈瘟标样的稻瘟病菌单孢菌株的全基因组进行PCR扩增,利用最长距离法和POPGENE 32生物学软件对其进行聚类分析和群体遗传多样性分析。结果显示,共分离获得189株稻瘟病菌菌株,13对SSR引物对其均能扩增出1条大小相同且清晰的条带,多态性位点百分率高达100.00%。供试189株稻瘟病菌菌株在相似系数为0.74时可划分为15个遗传宗谱,其中宗谱JXL01包含71株菌株,占总菌株数的37.57%,为优势宗谱;宗谱JXL02、JXL14为亚优势宗谱,分别包含31、26株菌株,占总菌株数的16.40%和13.76%;宗谱JXL03、JXL08、JXL10为次要宗谱,包含10～17株菌株;其它9个宗谱为小宗谱,包含菌株都在5株以下。在群体水平上,来源于不同生态型地区的5个稻瘟病菌群体的Nei’s基因多样性指数为0.375,Shannon信息指数为0.558,具有丰富的遗传多样性,且群体间差异较大;这5个种群基于非加权配对平均法大多聚为一类,种群遗传谱系与地理区域分布呈一定相关性,群体遗传多样性均值为0.373,存在一定的遗传分化,且群体内多样性大于群体间多样性,总遗传变异的64.56%存在于群体内。表明江西省稻瘟病菌群体结构既包含明显的优势宗谱,又存在复杂多变的特异性小宗谱,遗传多样性丰富,且与地理分布有一定的相关性。 相似文献