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C. G. PANAGOPOULOS 《EPPO Bulletin》1987,17(2):225-230
Bacterial blight of grapevine (caused by Xanthomonas ampelina) occurs in Greece, France, Spain, Italy, Turkey, Portugal, USSR and South Africa. It is a serious, chronic vascular disease which is widespread in some areas of grape production, affecting commercially important cultivars. There is evidence that the disease is presently spreading into new areas in some countries. The actual distribution of blight may be much wider, since its symptoms may be confused with those of other diseases. It is therefore essential to confirm the presence of X. ampelina by isolation and identification. X. ampelina is an anomalous member of the genus Xanthomonas which is readily distinguished on the basis of a few tests. The pathogen may also be rapidly detected in grapevine sap using the indirect immunofluorescence technique. The susceptibility of shoots to infections, under Cretan conditions, is highest from November to late January and very low during February and March. It has been found that up to 50% of apparently healthy canes obtained from diseased vineyards were latently infected. Transmission of the pathogen through soil and roots during the control of Daktulosphaira vitifolii or frost damage by flooding has been demonstrated in France. Several of the more widely grown cultivars were found to be very susceptible to the pathogen while no completely resistant cultivar has been detected. Control trials based on four sprays with a number of chemicals were unsuccessful. Control policy should be directed: (a) to preventing spread of the disease, by exclusive use of certified material; (b) to minimizing the disease in affected areas by suitable sanitary, cultural and preventive measures. 相似文献
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为了探求导致早期落叶病发生的土壤条件,分析果树栽培前与果园管理过程中存在技术问题,本研究以相同园龄、相同果树品种、落叶和不落叶的几个果园为研究对象,进行了果园土壤管理调查与土壤剖面化学性质的监测,测定了苹果果实的主要品质指标,结果表明:果园土壤有机质含量明显低于农田土壤,土壤表层,落叶果园土壤有机质含量要高于不落叶果园的,而在60 cm以下,落叶果园土壤有机质反而低于不落叶果园;而不落叶果园土壤中的碳酸钙含量略高于落叶果园;土壤剖面碱解氮含量随土层厚度的增加,呈递减趋势,不落叶与落叶果园土壤碱解氮含量在35 cm以上土层中基本相同,差异不明显(P>0.05);果实的密度测定结果为不落叶果园果实>落叶果园果实;在糖度上,不落叶果园果实>落叶果园果实。 相似文献
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Surveys were carried out in autumn 2004 and spring 2005 in the traditional areas dedicated to pome and stone fruit cultivation in Bosnia and Herzegovina to assess the presence, distribution and incidence of phytoplasma diseases in fruit trees. The occurrence of psyllid vectors was also considered. The detection of phytoplasmas in plant and insect samples and their identification were carried out by symptom observations in the field, double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA), nested polymerase chain reaction (nested-PCR) and restriction fragment length polymorphism (RFLP) analyses. Laboratory analyses showed the presence of phytoplasmas belonging to: (i) 16SrX group, subgroup A (' Candidatus Phytoplasma mali') in 23 out of 25 apple samples, in 4 groups out of 18 of Cacopsylla picta (synonym Cacopsylla costalis ) and in 2 groups out of 9 of Cacopsylla melanoneura ; (ii) 16SrX group, subgroup C (' Candidatus Phytoplasma pyri') in 11 out of 30 pears samples and in 2 groups out of 9 of Cacopsylla pyri ; (iii) 16SrX group, subgroup B (' Candidatus Phytoplasma prunorum') in 4 apricots, 2 peaches out of 42 stone fruit samples and in 1 group out of 14 of Cacopsylla pruni . The presence of different subtypes of Candidatus Phytoplasma mali, both in apple trees and in insects, was proven. 相似文献
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水果和蔬菜保鲜技术研究进展 总被引:7,自引:0,他引:7
介绍了目前国内、外一系列先进的水果和蔬菜保鲜技术,包括低温保鲜、化学保鲜、气调保鲜、涂膜保鲜、保鲜包装等;讨论了其优、缺点,并结合成本和安全性,分析了保鲜行业今后的发展趋势. 相似文献
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First report of Cucurbit aphid-borne yellows virus in Italy 总被引:2,自引:0,他引:2
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D. Ruano‐Rosa L. Schena G. E. Agosteo G. Magnano di San Lio S. O. Cacciola 《Plant pathology》2018,67(6):1362-1373
A homothallic Phytophthora species was found to be consistently associated with a rot of mature fruits of two local cultivars of olive (Olea europaea) in Calabria, southern Italy. The phylogenetic analysis of sequences of the ITS1‐5.8S‐ITS2 region and cox1 gene enabled its identification as a new species of clade 2, with a basal position compared to previously described subclades. The new species is described formally with the epithet Phytophthora oleae, referring to the natural matrix from which it was isolated. A unique combination of molecular and morphological characters clearly separates P. oleae from other already described Phytophthora species. This new species produced semipapillate, occasionally bipapillate, persistent sporangia on simple sympodially branching sporangiophores as well as globose and smooth‐walled oogonia, paragynous antheridia and spherical, plerotic oospores. The pathogenicity of P. oleae was confirmed in inoculation trials on fruits of three olive cultivars, including the two local cultivars from which the pathogen had been isolated. 相似文献
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Occurrence of Citrus psorosis virus in Campania, southern Italy 总被引:1,自引:0,他引:1
D. Alioto A. Troisi A. Peluso G. Quatrano V. Masenga R.G. Milne 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(8):795-799
Citrus psorosis virus (CPsV), genus Ophiovirus, is associated with a severe disease of citrus worldwide. Double antibody sandwich (DAS) ELISA using a polyclonal antiserum, and triple antibody sandwich (TAS) ELISAs, employing the IgG monoclonal antibody (mab) 13C5, and the IgM mab 2A3, were used to detect CPsV in orchards of different citrus varieties in Campania, southern Italy. TAS ELISA with 13C5 detected all the infections detected by DAS ELISA. Overall, 14% of trees younger than 15 years were positive, but only 1% of older trees, suggesting that infected propagating material has been increasingly used in recent years, in the absence of certification. Highest infection rates were in younger trees of sweet orange (22.8%) and clementine (18.6%). CPsV could easily be detected at all seasons of the year tested (June–January); these and earlier results indicate that TAS ELISA using 13C5 is a sensitive, broad-spectrum and reliable diagnostic method useful for routine tests and certification programmes. Of 44 field isolates responding strongly to DAS ELISA and 13C5-TAS ELISA, mab 2A3 gave similar results with 29 isolates, but gave low values with the others, thus providing a degree of differentiation among isolates. To confirm that the ELISA tests were indeed detecting CPsV, samples of 42 ELISA-positive plants were analysed by ISEM in a blind test, and in 38 of these, characteristic virus particles were clearly seen. Although CPsV was frequently and consistently detected in the area sampled, bark scaling symptoms were not seen: possible reasons for this are discussed. 相似文献
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Recent progress in understanding relationships betweenVerticillium species and subspecific groups 总被引:1,自引:0,他引:1
Randall C. Rowe 《Phytoparasitica》1995,23(1):31-38
Improved understanding of the genetic diversity within fungi in the genusVerticillium has resulted from recent studies based on vegetative compatibility analysis and several techniques of molecular biology.
Although the method used to identify vegetative compatibility groups (VCGs) does affect the results, vegetative compatibility
appears to be a stable characteristic among isolates. Fairly low VCG diversity has been detected withinV. dahliae andV. albo-atrum using nitrate non-utilizing mutants. VCGs do not appear to be related to pathogenicity to particular host species, with the
exception ofV. albo-atrum on alfalfa. However, there is some correlation with virulence on certain hosts and with the ability ofV. dahliae to interact with root-lesion nematodes. Studies based on DNA analysis indicate thatV. dahliae andV. albo-atrum are closely related but separate species. Restriction fragment length polymorphism (RFLP) studies have identified several
subspecific groups withinV. dahliae, including two non-host-adapted groups and two that are host-adapted. They also have confirmed that alfalfa strains ofV. albo-atrum are a distinct subgroup that is probably a separate population of clonal origin. Using polymerase chain reaction (PCR), a
second non-host-adapted subgroup withinV. albo-atrum was identified that was previously unknown. 相似文献
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Franco Gozzo Luigi Garlaschelli Pier M. Boschi Angela Zagni Jean C. Overeem Lambertus de Vries 《Pest management science》1985,16(3):277-286
The influence of structural variations in compounds of the N-acylalanine type, on their fungicidal activity towards Peronosporales, was examined. Within a series of methyl N-(acyl)-N-(2,6-xylyl)alaninates ( I ), a quantitative structure-activity relationship was given for the curative action against Plasmopara viticola, through a Hansch-type equation. A deviation from this equation is discussed with reference to benalaxyl ( I ; acyl=phenylacetyl). Syntheses and qualitative indications of activity are reported for structural changes in the xylyl and in the alanine moieties. Progress in the latter approach is briefly outlined. 相似文献