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   

Breakdown of resistance in cotton to cotton leaf curl disease in Pakistan   总被引：5，自引：0，他引：5  

S. Mansoor  I. Amin  S. Iram  M. Hussain  Y. Zafar  K. A. Malik  R. W. Briddon 《Plant pathology》2003,52(6):784-784

  相似文献   

First report of Carnation necrotic fleck virus (CNFV) infecting carnations in India     

G. Raikhy  V. Hallan  S. Kulshrestha  M. L. Sharma  Raja Ram  A. A. Zaidi 《Plant pathology》2003,52(6):801-801

  相似文献   

Die Wirkung elektromagnetischer Stimulation auf den Keimungsprozess von Weizen     

Branko Marinkovic  Miroslav Maleševic  Jovan Crnobarac  Hans-Jürgen Schaller  Franz Götz  Olaf Röder  Goran Jacimovic 《Gesunde Pflanzen》2003,55(6):187-190

  相似文献   

Die Biophysik in der Wachstumsfunktion von jungen Maispflanzen     

Branko Marinkovic  Novica Petrovic  Jovan Crnobarac  Hans-Jürgen Schaller  Franz Götz  Olaf Röder  Goran Jacimovic 《Gesunde Pflanzen》2003,55(6):184-186

  相似文献   

Application of fuzzy logic for the simulation of Plasmopara viticola using agrometeorological variables*     

S. Orlandini  A. Dalla Marta  I. D&#x;Angelo  R. Genesio 《EPPO Bulletin》2003,33(3):415-420

A mechanistic model called PLASMO was developed earlier to simulate grapevine downy mildew (Plasmopara viticola) and has been applied in several viticultural areas of Italy since 1988 by the collaboration of several research institutions of Firenze. In this study, a new simulation model based on fuzzy logic has been developed for the same structure (biological cycle of P. viticola). This approach allows classical quantitative information to be used together with qualitative information. Vague concepts can also be handled. Agrometeorological data is used, with an hourly time step, starting from budbreak to the end of the growing season. Air temperature, relative humidity, rainfall and leaf wetness are required. The simulated processes are the growth of grapevine leaf area and the main phases of the biological cycle of the pathogen: incubation, sporulation, germination, spore survival and inoculation. The main epidemiological outputs are timing of infection events and disease intensity. The performance of the model is evaluated and the mechanistic and fuzzy logic approaches are compared.  相似文献   

Control of the cowpea aphid, Aphis craccivora Koch (Homoptera: Aphididae), in cowpea, Vigna unguiculata (L.) Walp.     

THOMAS I. OFUYA 《Integrated Pest Management Reviews》1997,2(4):199-207

Cowpea, Vigna unguiculata (L.) Walpers, is a major dietary staple in tropical Africa where it is most often cultivated. The production is, however, greatly hampered by severe infestation and damage by insect pests including the cowpea aphid, Aphis craccivora Koch. The damage and bionomics of the aphid are briefly introduced. Chemical, cultural, physical and biological methods, and use of plant resistance for A. craccivora control in cowpea are reviewed. Finally, prospects for integrated pest management are discussed  相似文献   

Leafhopper and planthopper vectors of rice viruses and their management in Nepal     

G. DAHAL 《Integrated Pest Management Reviews》1997,2(3):139-159

Research on insect pests (including leafhoppers and planthoppers) in Nepal was initiated in 1956 by the Entomology Division and Plant Protection Units of the Department of Agriculture. More systematic work began after the establishment of a Rice Improvement Programme in 1972. Because of poor documentation and publication of research findings, it is difficult to assess the research efforts and achievements to date. The available research reports are mostly published in the proceedings of national seminars/workshops. They are used here to assess the current status of research on the occurrence and damage caused, distribution and composition, relative abundance, biology and management through chemicals. Much of past research has focused on insect surveys by light traps and sweep nets and the evaluation of insecticides and, since early 1990, some research on rice green leafhoppers (Nephotettix virescens and Nephotettix nigropictus) has begun to determine their relative abundance and population characteristics in relation to their potential as vectors of rice viruses. The challenges to pest management in general and some suggestions for future research needs are discussed, based on the present standing of agricultural research in the country  相似文献   

Phylogenetic relationships between rice dwarf phytoreovirus isolates from five countries     

B.C. Lee  Y.K. He  K. Murao  M. Isogai  G. Dahal  I. Uyeda 《European journal of plant pathology / European Foundation for Plant Pathology》1997,103(6):493-499

Rice dwarf virus isolates were collected from several locations in Japan, the Philippines, China, Nepal and Korea. Genomic dsRNA segment profiles in polyacrylamide gel electrophoresis differed among the isolates. There were less differences in the profiles between isolates from Japan and Korea than in those between these two Countries and others. Nucleic acid hybridization was used to examine the extent of genomic variation. Full-length cDNAs to all genomic segments encoding non-structural proteins (S4, S6, S9, S10, S11 and S12) were synthesized from two Japanese isolates, and were used for dot-blot hybridization. Hybridizations using probes generated from the full-length cDNA clones failed to differentiate isolates from different geographical areas. However, cDNA probes covering a variable region of S12 were able to distinguish Japanese and Korean isolates from those of other countries. Phylogenetic tree analysis based on the amino acid sequence of P12 encoded by S12 grouped Japanese and Korean isolates together. The Chinese isolates from two different locations (Yunnan and Fujian) were closely related to each other, and were the most distantly related to Japanese and Korean isolates.  相似文献   

Viruses in the northern potato-producing regions of Saudi Arabia   总被引：2，自引：0，他引：2  

I. M. AL-SHAHWAN  O. A. ABDALLA  & M. A. AL-SALEH 《Plant pathology》1997,46(1):91-94

Agar double diffusion tests and, later, ELISAs were used to detect viruses associated with potato in 242 samples collected in 16 trips to Tabuk and Hail, northern regions of Saudi Arabia, in four consecutive growing seasons (autumn 1989, spring and autumn 1990 and spring 1991). Eleven different viruses were detected in Tabuk and 12 in Hail. The viruses detected in Tabuk were alfalfa mosaic (AMV), cucumber mosaic (CMV), tobacco mosaic (TMV), potato leaf roll (PLRV), tomato spotted wilt (TSWV), tobacco ringspot (TRSV) and potato A, M, S, X and Y. The same viruses, plus potato yellow dwarf (PYDV), were detected in Hail. AMV was most frequently and CMV least frequently detected in Tabuk, whereas in Hail the most and least common were PVA and PLRV respectively.  相似文献