摘要:

AbstractSynthesis of tobacco mosaic virus (TMV)‐specific low molecular weight component RNA (LMC) was investigated in relation to that of other TMV‐related RNAs and proteins, and formation of progeny virus particles using synchronously infected tobacco mesophyll protoplasts.Timing of LMC synthesis was shown to be almost the same as, but somewhat earlier than that of TMV‐RNA synthesis. In contrast, synthesis of TMV‐specific double‐stranded RNAs (replicative intermediate, RI and replicative form, RF) as well as a high molecular weight virus‐induced protein (140 K protein) showed the maximum incorporation rate 4–6 h earlier than LMC synthesis. While, synthesis of coat protein and formation of progeny virus particles lagged behind LMC synthesis for 6–8 h.LMC occurring in polysomes was also investigated during the course of virus replication. The amount of produced coat protein calculated theoretically from the amount of LMC in polysomes of infected protoplasts was shown to be well agreed with the experimental results, indicating that LMC in polysomes is actively functioning as messenger for coat protien s

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00708.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe reproduction organs of maize are those most often attacked byUstilago maydis. In the male organs it produces a decline in free radicals concentration and, conversely, a rise of concentration in the female organs (in ears). The smut proper, grown on the flower, exhibits an essentially higher free radicals concentration than the smut grown out on the ear of that plant. A smut mixture from flower and ear has only a slightly higher free radicals concentration than the separate ear smut, but an essentially lower one than the smut of the flower.

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00709.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractEffects were examined of barley powdery mildew (Erysiphe graminisf. sp.hordei) on the major leaf protein, ribulose‐l,5‐bisphosphate carboxylase (RuBPCase), and other enzymes of CO2assimilation, phosphoenolpyruvate carboxylase (PEPcase) and malic enzymes, and enzymes associated with RuBPCase in the reductive pentose phosphate pathway. Activity of RuBPCase per unit fresh weight of leaf was inhibited by infection from the first sample, 3 days after inoculation, to the last sample, 24 days after inoculation, when healthy control leaves were visibly senescing. The inhibition occurred because the amount of RuBPCase protein (measured specifically by an immunological technique) was reduced from 6 days after inoculation and because activity per unit protein declined from 3 days until 21 days after inoculation, at which time there was little protein remaining. Activity of PEPcase per unit fresh weight of leaf was initially stimulated by infection but, thereafter, it was inhibited. Inhibition, like that also affecting malic enzymes (NAD) and (NADP), 3‐phosphoglycerate kinase, and glyceraldehyde‐3‐phosphate dehydrogenases (NAD) and (NADP), was associated with a decline in amounts of total soluble minus RuBP Case protein per unit fresh weight of leaf.Reduced amounts of leaf protein may be associated with reduced nitrate uptake by roots and fungal demand for nitrogen in mildew

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00710.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractBy measuring deposits of droplets downwind from a source in a barley crop during crop growth, gradients of deposition were established. Droplets were generated using a May spinning disc, which approximated to a point source. Droplets were labelled with thiabendazole so that deposit could be measured photometrically. Droplet diameter was approximately 20 micrometres, a size similar to spores of barley powdery mildew, an important foliar pathogen.Gradients of deposition were influenced by the density of the crop, by wind speed and by air turbulence. At any one time these three factors could interact to change the gradient substantially.Exponential and power law equations fitted the data equally well although due to experimental variation neither gave a very good fit. It is suggested that over the first few metres of dispersal from the source an exponential equation can be used to model the gradient. This has the advantage that it can be extrapolated to give an estimate of “self‐infection” i.e. the spores deposited on the plant on which they were pro

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00711.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractFalcarinol and falcarindiol were isolated from tomato vascular tissue infected withVerticillium albo‐atrumand identified. Separation and characterization of trimethylsilyl derivatives of four tomato phytoalexins could be obtained by capillary gas chromatographymass spectrometry.We are most grateful to Dr. P. J. G. M.deWit, Agricultural University, Wageningen, to Dr. D. T. Coxon, Food Research Institute, Norwich and to Dr. M. S. Kemp, Long Ashton Research Station, Bristol for making their analytical data available for us. Also thanks are due to Miss J. I. Liem, Mr. G. Verweijand C. Loriauxfor their assistanc

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00712.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractSpherical, coated microconidia‐aggregates as survival and dispersal units ofBotrytis cinereaPers.As a reaction to longer lasting unfavourable growth conditionsBotrytis cinereais able to form spherical microconidia‐aggregates enclosed in a protective coat. Genesis, structure and occurrence of these so far unknown microconidia‐aggregates are described and their function as survival and dispersal units of the fungus is disc

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00713.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractVein‐clearing followed by downward rolling and necrosis of leaves and severe stunting of groundnut (Arachis hypogaea) plants were caused by cowpea mild mottle virus (CMMV). The virus was readily transmitted by mechanical sap inoculations to groundnut and to 10 plant species belonging to Leguminosae, Chenopodiaceae and Solanaceae.Chenopodium quinoaandBeta vulgariswere good diagnostic hosts. Diseased sap remained infective at 10–3but not 10–4, when stored 8 to 9 days at 25 °C; for 10min at 75 °C but not 80°C. In limited tests, virus was not seed‐transmitted m groundnut or soybean. Virus was transmitted byBemisia tabacibut not byAphis craccivoraorMyzus persicae. An antiserum for CMMV was produced and virus was serologically related to CMMV reported on cowpea and groundnut crinkle virus (GCV) from West Africa. Employing carbon diffraction grating replica as a standard the modal length of virus particles to be 610 nm. Infected cells contained large number of virus particles associated with endoplasmic

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00714.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractGram (Cicer arietinumL.) was sown at different dates, viz., 15, 22, 29 Oct., 5, 12, 19 and 26 Nov., and 3 and 10 Dec. in 1978–1979 and 1979–1980 in four replications to enable observations to be made on the occurrence and severity of stem rot and wilt infection caused bySclerotinia sclerotiorum(Lib.) de Bary. The plant height and canopy width were also measured and correlated with the disease intensity. Yield of each plot was taken as the criterion for suggesting to farmers the best period of sowing the gram crop. November was the most suitable period for this purp

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00715.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractScanning electron microscopy showed that hyphae ofConiothyrium minitansproduced appressorium‐like swellings when they came in contact withSclerotinia sclerotiorumin dual culture on PDA. The parasitized hyphae gradually skrank and collapsed, and hyphae of the mycoparasite were found inside the host hyphae. The mycoparasite hyphae grew inter‐ and intracellularly within the sclerotia ofS. sclerotiorum. In the later stages of parasitism, hyphae of the mycoparasite proliferated extensively within the sclerotia and formed pycnidia near the sclerotial surface. At this stage, the sclerotia became flattened, soft and disintegrated. Sclerotia parasitized byC. minitansfailed to germinate either myceliogenically or carpogenica

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00716.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractA disease of sweet potato which causes dwarfing and shoot proliferation is reported from the Central Province of Papua New Guinea. The disease primarily effects yield by reducing tuber number and yield reductions of more than 50 % have been recorded. Mycoplasma like organisms have been detected in the phloem cells of diseased plants using electron microscopy and may be the cause of the disease. Early stage infections can be detected using fluorescent light microscopy and this may prove an appropriate method for rapid diagnosis of the disease. Treatment of diseased plants with tetracycline results in temporary symptom remission.

ISSN:0931-1785    

DOI:10.1111/j.1439-0434.1984.tb00717.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY