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1.
用K84对我国不同寄主来源的68个Agrobacterium tumefaciens菌株进行生物防治试验,结果表明:K84对我国桃树菌株的防治效果显著,对新疆的啤酒花菌株也有效;但对浙江萧山的部分啤酒花菌株无效;对甜菜菌株的防治效果不佳;对葡萄菌株基本上无效。对致病菌株的质粒类型的研究结果表明:桃树、啤酒花和甜菜菌株基本上都是胭脂碱(Nopaline)型质粒、葡萄菌株基本上是章鱼碱(Octopine)型质拉。试验中还发现不少胭脂碱型菌株不能被K84所防治。此外,在甜菜和毛白杨菌株中也发现了对细菌素A84(agrocin84)敏感,但不能被K84防治的菌株。 相似文献
2.
The damson hop aphid, Phorodon humuli (Schrank) (Hemiptera: Aphididae), is one of the most important sucking pests of many hop-growing areas world-wide. In this study we determined the efficacy of several insecticides against strains collected throughout the year 2001. All strains were collected in different hop gardens in the Hallertau (Bavaria), Germany, the largest hop-growing area of the world. First of all we established a leaf dip bioassay, carried out using six-well tissue culture plates and appropriate for monitoring susceptibility against imidacloprid, oxydemeton-methyl, cyfluthrin, amitraz, pymetrozine and pirimicarb. Four of these compounds, imidacloprid, cyfluthrin, pymetrozine and amitraz, are currently registered for the control of sucking pests in German hop gardens and are useful against P. humuli. The leaf-dip bioassay system turned out to be very reliable and robust. Ten P. humuli strains were collected in May 2001 and maintained in the laboratory to assess their resistance to the different insecticides in comparison with two laboratory reference strains (H2 and H5). Using diagnostic concentrations, resistance monitoring for imidacloprid and cyfluthrin was investigated during July and August 2001 on 53 populations from 30 sites around the Hallertau, an area of ca 2500 km2. Resistance to diagnostic concentrations (LC95 for reference strains) of imidacloprid, amitraz and pymetrozine was not detected in any strain received in 2001, but late-season (August) populations seemed to respond more heterogeneously than those collected mid-season (July). Overall composite mean mortalities to diagnostic concentrations of imidacloprid (13 mg litre(-1)) in collections from May, July and August were 95 (+/-2.5), 98 (+/-2.3) and 87 (+/-5.9)%, respectively. Moderate resistance to pyrethroids was observed in all strains collected in May and August using a diagnostic concentrations of 10 mg litre(-1) cyfluthrin (LC95 of the susceptible reference strain H5). Slight to moderate resistance to diagnostic concentrations of oxydemeton-methyl and pirimicarb was observed in some, but not all, strains collected early season. The results are discussed in terms of the implemention of hop aphid resistance management strategies in German hop-cultivation areas. 相似文献
3.
Downy mildew of hop, caused by Pseudoperonospora humuli , is an important disease in most regions of hop production and is managed largely with regular fungicide applications. A PCR assay specific to P . humuli and the related organism P . cubensis was developed and used to monitor airborne inoculum in hop yards to initiate fungicide applications. The PCR amplified as little as 1 fg of genomic DNA of P . humuli , and yielded an amplicon in 70% of reactions when DNA was extracted from single sporangia. In the presence of 25 mg of soil, an amplicon was amplified in 90% of reactions when DNA was extracted from 10 or more sporangia. During nine location-years of validation, PCR detection of the pathogen in air samples occurred no later than 8 days after the appearance of trace levels of disease signs and/or detection of airborne spores in a volumetric spore sampler. Inoculum was detected on average 4·5 days before (range −8 to 14 days) the first appearance of basal spikes in six commercial yards, or 1·3 days after (range −5 to 1 days) sporangia were detected in a volumetric spore sampler in experimental plots. In commercial yards, use of PCR to initiate the first fungicide application led to enhanced disease control or a reduction in fungicide use in four of six yards compared to growers' standard practices. These results indicate that the efficiency and efficacy of hop downy mildew management can be improved when control measures are timed according to first detection of inoculum. 相似文献
4.
Deep‐sequencing revealed Citrus bark cracking viroid (CBCVd) as a highly aggressive pathogen on hop 
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下载免费PDF全文 Newly emerging or re‐emerging diseases are a constant and significant threat to agricultural production, so prompt and accurate identification of the causative agents is required for rapid and appropriate disease management. Classical methods of pathogen detection can be successfully supplemented by next‐generation sequencing (NGS), whereby sequence analysis can help in the discovery of new or emerging diseases. In 2007, hop growers in Slovenia reported the appearance of severely stunted hop plants, a phenomenon that spread rapidly within hop gardens and among farms. Classical diagnostic methods were unable to detect a new pathogen; therefore, single step high‐throughput parallel sequencing of total RNA and small RNAs from plants with and without symptoms was employed to identify a novel pathogen. The sequences were assembled de novo and also mapped to reference genomes, resulting in identification of a novel sequence of Citrus bark cracking viroid (CBCVd) in the stunted hop plants. Furthermore, the presence of this novel pathogen on hop was confirmed by RT‐PCR analysis of 59 plants with symptoms from 15 hop gardens, representing the main outbreak locations identified by systematic disease monitoring, and small RNA Illumina sequencing of the bulked RNA sample. The high infectivity of the newly identified CBCVd was also confirmed by biolistic inoculation of two hop cultivars, which developed aggressive symptoms in controlled conditions. This study shows the feasibility of deep sequencing for the identification of causative agents of new diseases in hop and other plants. 相似文献
5.
The neonicotinoid insecticide imidacloprid is the most important insecticide in hop cultivation in Germany. A laboratory study was undertaken to investigate its systemic properties and translaminar bioavailability in hop leaves. Radiolabelled [methylene-14C]imidacloprid was applied either alone or in combination with different additives onto leaves of several hop varieties. Uptake and translocation were evaluated 1 and 7 days after foliar application under greenhouse conditions. The uptake of imidacloprid into hop leaves was most pronounced in the first 24 h after application and only negligible amounts were taken up after this period. Significant differences in the quantitative uptake occurred when imidacloprid was combined with additives, such as Amulsol, Genapol C-100, Hasten and LI 700. The uptake of imidacloprid applied without additives was less than 10% 7 days after application, whereas the combination with LI 700 provided 70-80% uptake. Genapol C-100 and Amulsol induced considerable phytotoxicity at the application site. Comparing hop varieties revealed differences up to twofold in foliar penetration of imidacloprid. The translaminar and acropetal bioavailability of imidacloprid foliarly applied to hop leaves was determined by a laboratory bioassay using the damson hop aphid, Phorodon humuli (Schrank). Significantly higher mortality was observed with laboratory formulations containing imidacloprid and the additive LI 700. In contrast to these results from systemic tests, contact mortality at the application site was constantly high over the testing period of 7 days, highlighting the importance of this mode of entry for aphid intoxication. 相似文献
6.
The in vitro production of extracellular polygalacturonase, pectin lyase, and cellulase by hop isolates of Verticillium albo-atrum was studied. A total of 24 isolates belonging to the two pathotypes commonly described as fluctuating or progressive, according to the symptoms produced in certain susceptible hop cultivars, were grown in liquid shake cultures. The media used contained glucose, pectin or acetone-extracted hop tissue as a carbon source. The production of all three enzymes was significantly correlated with pathotype when the medium contained hop tissue. Pectin lyase production was also correlated with pathotype when pectin was used as the carbon source. The influence of carbon source on enzyme output and possible reasons for some exceptions to the correlations observed are discussed. 相似文献
7.
Sebastjan Radišek Jernej Jakše Branka Javornik 《European journal of plant pathology / European Foundation for Plant Pathology》2006,116(4):301-314
Verticillium wilt, caused by Verticillium albo-atrum or V. dahliae, is an important disease of many worldwide crop species. In Europe, V. albo-atrum isolates infecting hop express different levels of virulence, inducing mild or lethal disease syndromes, and it is therefore an attractive model for studying the virulence of this pathogen. In this work, eleven amplified fragment length polymorphism (AFLP) primer combinations were used to analyze genetic variability among 55 V. albo-atrum hop isolates from four European hop growing regions, as well as isolates from other hosts and V. dahliae isolates. Cluster analysis divided V. albo-atrum and V. dahliae isolates into two well-separated groups. Within the V. dahliae cluster, isolates were separated without host specific grouping, although no host adapted isolates were included. In V. albo-atrum, the alfalfa isolates were distinct from isolates of other hosts, where a high association with virulence was observed in hop and tomato isolates. All lethal hop isolates were genetically different from mild hop isolates. The lethal hop isolates from England and Slovenia expressed the same virulence phenotype, although they showed a different AFLP pattern. The mild hop isolates formed two subgroups, to which isolates clustered irrespective of geographical location. These data suggest multiple origins of V. albo-atrum hop isolates, and the possible appearance of new virulent isolates in the future in other hop growing regions. 相似文献
8.
In order to assess the potential of infection of hop powdery mildew it is important to know the spore dissemination coming from different sources. Overwintering via cleitothecia is not provable in experiments. So wild hops, not correctly cleared cultural hops and non-cultivation hops are potential carriers of powdery mildew which is overwintering via mycel. In 2007 we found a source which has infected an area of about 30?ha cultural hops. By the observation of infections in these hop gardens we found that half of the amount of conidia is in a distance of 9,55?m away from the source. In a smaller dimension we counted the amount of conidia around one single plant in a commercial hop garden by a special spore trap. In the single plant the amount of spores is lower than outside, while it is decreasing in a higher distance from the single plant. Analysing the micro spore dissemination in a single plant there was a big diversity of the amount of spores because of the complex architecture of the hop plants. Further studies showed that the susceptibility of hop is much higher in May than later in the year. Thus, statistically a lower amount of conidia is needed for one complete infection. However, a lower amount of conidia can easily be transported for long distances by wind. As a result a source of powdery mildew in a long distance from the cultural hops is a serious danger for the commercial hop gardens early in the year. Later each source of conidia looses its influence nearly completely. 相似文献
9.
Forty-two percent of leaf samples taken from hop cv. Qingdao Dahua growing in plantations in northeastern China in 1983-1984 were infected with hop mosaic virus (HMV) and/or hop latent virus (HLV). Mosaic or line-pattern symptoms were seen in some plants but only in spring and it is uncertain if the symptoms were caused by either virus which appeared in our studies to be similar, both serologically and in host range, to HMV and HLV described in Europe and North America. In host range studies, HMV infected Nicotiana clevelandii systemically without inducing symptoms. Occasionally it caused chlorotic spots in the inoculated leaves of Chenopodium quinoa and brown star-point lesions in inoculated leaves of Phaseolus vulgaris cv. Topcrop, The virus was purified by PEG precipitation from extracts of N. clevelandii plants; yields were about 40-120 mg/kg fresh leaves. The virus contained a single protein (estimated molecular weight 34 200) that was estimated to contain 272 amino acids with no methionine, and a single RNA species (estimated molecular weight 295 x 106 ) that represented c. 6% of the particle weight. HLV sometimes caused inconspicuous chlorotic spots in inoculated leaves of C. murale and local pinpoint lesions in P. vulgaris in winter only. A virus similar to alfalfa mosaic virus was isolated from leaves of hop cv. Golding and caused systemic necrotic symptoms in C. quinoa and C. amaranticolor , and systemic chlorotic spots in hop cv. Styrian. 相似文献
10.
Peter M. Lsel Michael Lindemann Jürgen Scherkenbeck Johann Maier Bernhard Engelhard Colin A. M. Campbell Jim Hardie John A. Pickett Lester J. Wadhams Alfred Elbert Gerhard Thielking 《Pest management science》1996,48(4):293-303
Field experiments employing yellow water-traps with vials releasing methyl salicylate, butyl isothiocyanate, 4-pentenyl isothiocyanate and diethyltoluamide were conducted during the spring migration of Phorodon humuli (Schrank), with the aim of identifying substances which might be used in the field to deter landing on hop plants. Methyl salicylate and the two isothiocyanates reduced trap catches of P. humuli. During the spring of 1994 a slow-release formulation of methyl salicylate and a β-acid-rich hop resin sprayed on to hop plants did not reduce aphid infestations significantly. In autumn cis,cis-nepetalactol, the main component of P. ‘humuli’s sex pheromone, prepared by various synthetic routes, increased trap catches of males and gynoparae equally. Catches of males in pheromone traps situated in a hop garden decreased with increasing trap height. Catches of males in traps charged with increasing doses of the cis,cis-nepetalactol peaked at 1 mg and then plateaued, whereas catches of gynoparae peaked similarly at 1 mg and then decreased. The effects of kairomones from an extract of the primary host, sex pheromone and a visual cue from yellow compared with clear water-traps were additive. The prospects for developing a semiochemicals-based control strategy against P. humuli, using some or all of the above elements, are discussed. 相似文献
11.
Diversity of the coat protein-coding region among Ilarvirus isolates infecting hop in Australia 总被引：1，自引：0，他引：1
D. R. Crowle S. J. Pethybridge G. W. Leggett L. J. Sherriff C. R. Wilson † 《Plant pathology》2003,52(5):655-662
Coat protein (CP) sequences of 17 Ilarvirus isolates were obtained from hops at three farms in Tasmania, Australia. Phylogenetic analysis of these sequences and additional database sequences indicated several Apple mosaic virus (ApMV) isolate clusters distinct from Prunus necrotic ringspot virus (PNRSV): one containing isolates from apple; one containing a single isolate from almond; a third containing Australian hop isolates of the 'apple' serotype and a German isolate of unknown origin; and a fourth containing Australian hop isolates of the 'intermediate' serotype. Isolates from hop, pear and prune from the Czech Republic either formed a fifth grouping, or were divergent members of the 'intermediate' serotype group. Deduced amino acid (aa) residue differences between the coat proteins of the two hop isolate serotype groups were highlighted as possible regions of serological differentiation. No evidence for coinfection of plants with both serotypes was found. Tests of ApMV-infected hop buds using the Shirofugen flowering cherry assay revealed a possible differentiation of the two strains based on hypersensitivity. Because of serological similarities to PNRSV, these viruses have commonly been reported as strains of PNRSV. However, this study shows ilarviruses from Australian hops are strains of ApMV, but distinct from those infecting Malus spp. 相似文献
12.
啤酒花根癌病在我国发生普遍,是影响啤酒花生产的重要病害。从啤酒花主要生产基地新疆、山东、浙江等地分离到61个菌株。通过培养性状、染色反应,以及14～15个菌株的生理生化性状和12个菌株致病性的测定,确定啤酒花根癌病病原菌为根癌土壤杆菌Agrobacteria tumefaciens(E.F.Smith &Jownsend)Conn属生物型1、病原菌菌株对K84(Agrobacterium radiobacter)菌株的细菌素敏感,各菌株间敏感性的强弱不一。盆裁番茄和啤酒花初步生防试验表明,用K84与敏感性强的菌株按1:1比例混合接种,番茄和啤酒花都不产生瘿瘤;而敏感性弱的菌株需用3:1才能防止瘿瘤的产生。 相似文献
13.
Three fluctuating (M18, M33 and M50) and three progressive (PVl, PV2 and PV3) hop wilt isolates of Verticillium albo–atrum Reinke and Berthold were tested against the hop ( Humulus lupulus L.) cultivars, Fuggle, Wye Challenger and Wye Target. Significant differences in pathogenicity were observed between progressive and fluctuating isolates and although wilt symptoms varied in intensity from season to season, the relative order of pathogenicity and host resistance usually remained the same. Using a detached leaf procedure, differences were observed in the frequency of successful re–isolations of Vertieillium from hop plants infected with wild–type isolates. This procedure is discussed as a possible additional method for distinguishing between progressive and fluctuating hop wilt isolates. Auxotrophic and morphological mutants derived from these six wild–type isolates were tested under glasshouse conditions against hop and the non–selective alternative host Antirrhinum majus L. (cv. Maximum). Although auxotrophic mutants generally showed a reduction in pathogenicity to, and ability to colonize, both hop and Antirrhinum , certain auxotrophs retained near–parental levels of colonization and were therefore suitable for studies on possible parasexual recombination in these hosts. 相似文献
14.
15.
啤酒花的地理分布与中国的野生啤酒花资源 总被引：2，自引：0，他引：2
啤酒花隶属于桑科葎草属,全世界共有该植物5变种,分布遍及北半球,间断分布于欧亚大陆和北美洲。作者通过对中国新疆地区啤酒花的实地调查,结合所搜集的啤酒花的文献资料,对啤酒花的起源,分化和地理分布进行讨论,并提出保护野生啤酒花资源的建议。 相似文献
16.
Zhixiang Zhang Ying Zhou Rui Guo Lingxiao Mu Yuanai Yang Shifang Li Hongqing Wang 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(2):217-225
A survey for the incidence of Hop stunt viroid (HSVd) infection in China was conducted using dot-blot hybridization. Out of 553 tested samples, 127 samples of stone fruits (apricot, peach, plum and almond), grapevine and hop were positive for HSVd, giving a mean infection rate of 23?%. Phylogenetic analysis revealed that most of the HSVd variants isolated from stone fruits, grapevine and hop were clustered into known hop and plum groups. However, two grapevine variants, HSVd.g50 and HSVd.g57, could not be clustered into any known groups, indicating a previously unknown phylogenetic group of HSVd isolates. HSVd.g38 was the single grapevine variant that clustered with the plum group isolates, supporting cross transmission between grapevine and stone fruits and the heterogeneity of grapevine isolates. 相似文献
17.
Leaf mesophyll protoplasts and cell suspension cultures obtained from resistant and susceptible cultivars of hop ( Humulus lupulus ) exhibited differential cell death responses when treated with sterile culture filtrates (CF) obtained from four isolates of Verticillium albo-atrum showing a range of virulence towards hop. The extent of cytotoxicity was correlated with both the virulence of the isolates and the resistance of the cultivars. Cytotoxicity was attributed to a low-molecular-weight, heat-labile, component of CF. Cell cultures from a susceptible and a resistant cultivar exhibited similar, growth-related, patterns of sensitivity to CF. The extent of inhibition of callus growth caused by CF treatment was related to the level of the resistance of the cultivar. 相似文献
18.
The downy mildew pathogen, Pseudoperonospora humuli, forms oospores abundantly in diseased hop tissue. Diverse monosporangial isolates of P. humuli derived from samples collected in Japan, Germany and the USA readily formed oospores within hop leaves when inoculated singly, suggesting homothallism. Single zoospore isolates also readily formed oospores within hop leaves, further supporting the homothallic nature of this oomycete. The majority of oospores were deemed viable based on cytoplasm characteristics and plasmolysis assays. However, disease symptoms failed to develop when hop leaves were inoculated with newly formed oospores, even when oospore conditioning was attempted with treatment with potassium permanganate or β‐glucuronidase/arylsulphatase, brief exposure to freezing temperature, or passage through an earthworm. Oospores derived from a monosporangial isolate of P. humuli that overwintered outdoors in infested leaves buried in soil also failed to cause downy mildew. Pseudoperonospora humuli is homothallic and oospores of the organism appear to require as yet unknown conditions to stimulate their germination and/or infection. 相似文献
19.
The hop looper, Hypena humuli Harris (Lepidoptera: Noctuidae), is becoming an increasingly important pest of hops (Humulus lupulus L.) (Rosales: Cannabaceae) in western USA. Currently, control of this pest usually involves broad-spectrum pesticides that kill natural enemies and disrupt biological control of other hop pests. In order to develop better management strategies for H. humuli, field and laboratory studies were conducted over a four-year period to identify the pest's natural enemies and to investigate their phenologies and to assess their impact. Nine parasitoid species and assorted species of invertebrate predator were found to attack different life-stages of H. humuli. Levels of parasitism were consistently low throughout the study period and none of the parasitoids found was a specialist natural enemy of the pests. Exclusion cage studies showed, however, that the complex of natural enemies as a whole can significantly reduce larval densities of the pest, and laboratory studies confirmed successful predation of H. humuli larvae by several generalist predators including the European earwig (Forficula auricularia L.), the damsel bug Nabis alternatus Parshley and two species of the geocorid bug genus Geocoris. 相似文献
20.
M. G. Solomon 《Phytoparasitica》1992,20(1):S51-S56
A wide range of species of predators has been exploited, or has the potential to be exploited, as biological control agents against pests of fruit and hop. They include members of the families Miridae, Anthocoridae and Chrysopidae, and of the mite family Phytoseiidae. Some species can colonise fruit plantations naturally, whereas others are mass-cultured and introduced artificially. The characteristics of the various predator species are considered in relation to the requirements for biological control agents in specific crop situations. 相似文献