摘要:

SummaryWhen particles of Kashmir bee virus (KBV) and sacbrood virus (SBV) were fed to larvae of the honey bee,Apis mellifera, in Australian colonies, the resulting pupae became in apparently infected. There was no statistically significant difference in the susceptibility of 1, 2, 3 or 4‐day‐old larvae for either virus, but 5‐day‐old larvae were significantly less susceptible to SBV than younger larvae. There was no significant difference in the proportions of pupae that became in apparently infected when, as larvae, they were fed various concentrations of each virus, but significantly more larvae were removed from their cells when fed concentrated preparations of each virus than when fed diluted preparations. Susceptible larvae that became in apparently infected with KBV and SBV developed normally into in apparently infected pupae and later, emerged as in apparently infected work

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06781.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryThe phytotoxicity of methyl bromide gas on chrysanthemum cuttings was investigated in relation to gas concentration, length of exposure, temperature, and variety and age of cuttings. Concentrations of 10.5 to 13.5 g/m3for 4 to 5 h produced a concentration time product (CTP) of 54 g h/m3which is suitable for safe fumigation of most varieties of chrysanthemum. Length of exposure was not critical up to 5 h. However, fumigations of cuttings which were more than 3 wk old generally caused excessive phytotoxicity and therefore cannot be recommended. There was less damage at temperatures of between 14 and 16°C than at higher temperatures. A table of predictions from a fitted regression equation is included to demonstrate the increased susceptibility of chrysanthemums at higher temperatures and ages of cuttings

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06782.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryThe intensities of foliar infection (leaf blight and shot hole) and pod rot, caused byColletotrichum gloeosporioides, were recorded from a cocoa‐areca mixed garden and a cocoa‐monocrop garden during 2 years. The intensity of pod rot was recorded from both the gardens. The intensities of leaf blight and shot hole gradually increased from July, reached a peak during September‐November, decreased thereafter and reached the lowest level during April‐June. Increase in leaf infection was associated in both plantings and in both years with the period of rain (June‐November). The phylloplane population of C.gloeosporioidesalso increased during June‐November when the temperature tended to be low and constant with high rainfall and relative humidity. During this period there were few susceptible stages of pods (cherelles and young pods) and pod infection was very low. Nearly mature pods were free from infection. I n both years, pod infection was more in the cocoaareca mixed garden than' in the cocoa‐monocrop; it was observed during January‐May, when the susceptible stages were mostly prevalent but when theC. gloeosporioidespopulation was low and the climatic factors appeared to be relatively unfavourable. This may be one reason for the lesser incidence of pod rot when compared to

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06783.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryConidia of two isolates ofElsinoe venetawere consistently producedin vitroby a 3‐stage culture system in which sparsely sporulating microcolonies produced on corn meal agar were used to ‘seed’ Czapek‐Dox V8 juice agar.E. venetathen sporulated on this medium if dises were floated mycelium uppermost on sterile distilled water for 24 h at 25°C. Both isolates also produced microconidiain vitro.Only the growing apices of raspberry canes were susceptible to infection. Of 12 genotypes inoculated in the glasshouse, a red raspberry derivative ofRubus coreanus, EMRS 2769/9, was the most resistant and the black raspberry selection SCRI 815286 and cv. Malling Delight were the most susceptible. Of four red raspberry cultivars inoculated in the field cv. Malling Orion was the most susceptible. Inoculated flowers and developing fruits produced malformed fruits because infected drupelets were smaller or slower to ripen than uninfec

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06784.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryA histological survey was made of the canes of several raspberry genotypes inoculated in the field and glasshouse withElsinoe veneta. Acervuli bearing conidia developed on all genotypes and hyphae penetrated the cortex, polyderm and phloem inducing extensive cell divisions, utilisation of starch reserves and deposition of suberin and lignin‐like materials in these tissues.The results indicated that the polyderm was invaded via the passage cells at an early stage in its development. Phloem fibre cells surrounded by lignified middle lamellae were rarely infected, but since the fibre bundles did not form a complete sheath around the vascular tissues, hyphae spread between the bundles to invade the phloem in all genotypes. The deposition of suberin and lignin‐like materials in host cells in the cortex, phelloid cells of the polyderm and phloem partially restricted the spread of mycel

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06785.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryCross‐protection experiments were performed inChenopodium quinoausing arabis mosaic virus (ArMV) and grapevine fanleaf virus (GFLV) isolates.Two factors were specially studied, namely the time interval and the distance between the two inoculations, respectively, with the hypovirulent isolate and with the hyper virulent challenge isolale.ArMV‐S clearly protectedC. quinoafrom a super infection with GFLV‐F13 as shown by a diminution, or even suppression, of the synthesis of the coat protein and the nucleic acids of the GFLV‐F13 isolate. In the homologous interaction between GFLV isolates (GH and F13), protection was also observed. In the interaction between GFLV‐GH and ArMV‐862, by contrast, symptoms were typical of the hyper virulent ArMV‐862 and the amount of coat protein of ArMV

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06786.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryA cDNA library was produced from the RNA of a Swedish MAV‐like isolate of barley yellow dwarf virus (BYDV). The procedure involved random priming and the ds cDNA was cloned into the EcoRl site of the plasmid pUC19. Among the clones obtained some hybridised specifically with MAV‐like isolates whereas others also hybridised with PAV‐like isolates. Only very weak hybridisation was observed with an RPV‐like isolate. An Australian cDNA clone, reported to be PAV‐specific (pBY82, Waterhouse, Gerlach&Miller, 1986), hybridised with Swedish MAV‐like but not with PAV‐like isolates. Probes prepared from the clones detected virus in plant extracts by dot‐blot hybridisation with sensitivity greater than that of ELISA. Virus was also readily detected in extracts of viru

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06787.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryAnthriscus yellows virus (AYV), a phloem‐limited virus transmitted in the semi‐persistent manner by the aphidCavariella aegopodii, waspurified by treatment of leaf extracts with cellulasc, followed by differential and sucrose density gradient centrifugation. ‘The preparations contained isometric particlesc. 29 nm in diameter which were unstable unless stored in buffer at pH 8.0 containing 1 mM CaCl2,. The particles sedimented as two components, ’full‘ nucleoprotein particles with A260/A280= 1.83 containing about 42% nucleic acid, and ’empty‘ protein shells withA260,/A280=0.73; their buoyant densities in CsCl solutions were 1.52 and 1.27 g/cm3. Respectively. Yields of ihe nircleoprotein particles were c. 1.75 mg/kg leaf tissue. The particles contained a single species of RNA, of mol. wt 3.6 × 10 “(10 000 nucleotides). Particle protein preparations contained four electrophoretic species, of mol. wt (× 103) 35.0, 28.3, 23.3 and 22.3.C. aegopodiidid not transmit AYV from purified preparations. A rabbit injected with AYV preparations produced antibodies that coated AYV particles in electron microscope tests, but gave variable reactions in immunosorbent electron microscopy (ISEM), depending on the composition of the medium. No reactions were obtained in enzyme‐linked inimunosorbent asjay (ELISA). No serological relationship was detected in ISEM between AYV and any of 10 viruses that resembled it in one

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06788.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryParticle preparations of parsnip yellow fleck virus (PYFV) isolates A‐421 and P‐121, representing the two major serotypes, were made by clarifying leal extracts with ether or butan‐1‐ol and concentrating the virus particles by precipitation with polyethylene glycol and differential centrifugation. The preparations containedc. 31 nm‐diameter particles comprising two sedimenting components. Top component (T) consisted of stain‐penetrable protein shells withA260/A280=0.8–0.9, sedimentation coefficient (S20) =56 S (A‐421) or 60 S (P‐121), and buoyant density = 1.297 g/cm3. Bottom component (B) consisted of nucleoprotein particles, not penetrable by negative stain, withA260/A280= 1.9, sedimentation coefficient (S020.w) = 148S(A‐421) or 153 S (P‐121), and buoyant density = 1.520 g/cm3(A‐421) or 1.490 g/cm3(P‐121). Yields of B component particles were up to c. 1 mg/100 g leaf tissue (both isolates); yields of T component particles were up toc. 0.6 mg (A‐421) or 5.5 mg (P‐121) per 100 g leaf tissue. PYFV particles were found to contain a single RNA species (mol. wtc. 3.4 × 106,c. 9800 nucleotides), constituting 40% of the particle weight, and three polypeptide species, of mol. wt (× 103)30, 26 and 24

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06789.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

SummaryIsolates of parsnip yellow fleck virus (PYFV) from parsnip (P‐121), celery (CV506 and CV065) andHeracleum sphondylium(Hs2) were serologically close to each other but distant from isolates from carrot (Dc2 and Dc5) andAnthriscus sylvestris(A‐421 and As2), which were in turn close to each other serologically. The two groups of isolates also differed from each other in host range. Minor differences in immunological reactions and in host range and symptomatology were observed between isolates in each group. Particles of all eight isolates had similar RNA and protein compositions. The data confirm that PYFV isolates fall into two major serotypes, those from parsnip, celery andH. sphondyliumbelonging to the P‐121 serotype and those from carrot andA. sylvestrisbelonging to the A‐421 s

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1989.tb06790.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY