bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incidence and severity of pest and disease damage to white clover foliage at 16 sites in England and Wales
Authors: LEWIS G. C. , THOMAS B. J. 
Published: February 2008

SummaryFrom 1985 to 1987, leaves of white clover (Trifolium repens) cv. Grasslands Huia were examined for damage by pests and fungal diseases on seven occasions at up to 16 sites in England and Wales. Pest damage was recorded at all sites on all sampling dates. Over all sampling dates, the mean number of leaves damaged by slugs ranged from 23% to 67%, and that by weevils (Sitona spp.) ranged from 3% to 62%. Also, up to 30% of leaves were damaged by other, unidentified pests. At individual sites, total pest damage frequently exceeded 90% of leaves. The area of leaf damaged by pests ranged from 2 ‐ 12%. Fungal diseases were recorded in July and September but not in May, and were more prevalent in September 1985 than in September 1986 or 1987. Black blotch (Cymadothea trifolii) was the most frequently recorded disease, and the mean number of leaves damaged ranged from 4% to 21%. The mean area of leaves covered by lesions was 1–2%. Infections by viruses were assessed on two occasions, using indicator plants and electron microscopy, and only a very low incidence of arabis mosaic virus and red clover necrotic mosaic virus was recorded.
Studies on transmission of Indian peanut clump virus disease by Polymyxa graminis*
Authors: RATNA A. S. , RAO A. S. , REDDY A. S. , MOLT B. L. , REDDY D. V. R. , VIJAYALAKSHMI M. , McDONALD D. 
Published: February 2008

SummaryThe plasmodiophoromycete fungus, Polymyxa graminis was observed in the roots of Sorghum bicolor, S. sudanense, Pennisetum glaucum, Triticum aestivum, Cyperus rotundus, Eleucine coracana, Zea mays, Tridax procumbens and Arachis hypogaea collected from Indian peanut clump virus (IPCV)‐infested fields. Examination of roots of IPCV‐infected S. bicolor, S. sudanense, P. glaucum and T. aestivum grown in previously air dried field soil also showed the presence of cystosori of P. graminis. IPCV‐infested soil stored at room temperature for 3 years transmitted the virus to A. hypogaea, T. aestivum and S. bicolor. Roots extracted from IPCV‐infected P. glaucum and S. bicolor containing cystosori, and dried root fragments incorporated into sterile soil, transmitted the virus to A. hypogaea and T. aestivum. The root extracts contained primary zoospores of the fungus, presumably arising from cystosori. Utilising root fragments of S. sudanense containing cystosori as inoculum P. graminis was shown to infect both monocotyledonous and dicotyledonous plants. Profuse cystosorus production in rootlets only occurred in monocotyledonous plants. In dicotyledonous plants, in general, only few rootlets showed cystosori. Indian isolates of P. graminis appear to differ from isolates from temperate soils in that they can infect dicotyledonous plants and have a much wider host range.
Monoclonal antibodies against tomato spotted wilt virus: Characterisation and application*
Authors: ADAM G. , LESEMANN D. ‐E. , VETTEN H. J. 
Published: February 2008

SummaryMouse hybridoma cells, secreting monoclonal antibodies (MCA) against tomato spotted wilt virus, were produced and screened for virus specificity by an indirect triple antibody ELISA, using a rabbit polyclonal antiserum for antigen trapping. A Bulgarian virus isolate from tobacco was used for immunisation of mice and rabbits. One fusion eventually led to 10 stable hybridoma cell lines, all of which produced antibodies of IgG‐type though of different subgroups. Since none of the MCAs reacted with TSWV structural proteins after electrophoresis and transfer to nitrocellulose, other methods were chosen to examine their protein specificity. Purified viral cores and detergent‐solubilised envelope proteins were used as antigens for ELISA, or, alternatively, glycosylated viral envelope proteins were trapped onto microtitre plates coated with lectins in order to detect MCAs specific for them. Both methods, independently, led to the identification of two MCAs that were specific for envelope proteins of TSWV. Only these two antibodies reacted with intact TSWV particles when examined by immunogold labelling in the electron microscope. The reaction of all MCAs with 11 different TSWV isolates eventually led to the selection of one core‐ and one envelope‐specific antibody for routine use. Core‐specific MCAs revealed serological differences between isolates belonging to the common serotype (= lettuce serotype), but did not react with the serotype TSWV‐I. When comparing different ELISA procedures, broadest reactivity and highest sensitivity with different isolates were obtained in an indirect test procedure, using goat anti‐mouse antibody conjugates.
Improving the selectivity of water traps for monitoring populations of the cabbage root fly
Authors: FINCH S. 
Published: February 2008

SummaryTraps placed within brassica crops to monitor changes in cabbage root fly activity could be made more selective by painting black the inner wall of the standard fluorescent yellow water‐traps. Traps could also be made more selective by covering them with cylinders of Netlon mesh, although this procedure reduces the numbers of cabbage root fly caught by about 70%. Of the single‐coloured traps tested, those painted “marigold” yellow were the most selective in capturing female cabbage root flies. Although white and certain blue traps were as effective as the best yellow traps at capturing cabbage root flies, such traps should be avoided, as they catch 4–5 times as many of the closely‐related bean seed fly. The presence of bean seed flies makes cabbage root fly identification more difficult and adds considerably to the time required to sort trap catches.
The impact of two insecticides on predatory ground beetles (Carabidae) in newly‐sown grass
Authors: ASTERAKI E. J. , HANKS C. B. , CLEMENTS R. O. 
Published: February 2008

SummaryField scale experiments carried out over three years showed that chlorpyrifos reduced the numbers of several carabid beetle species caught in pitfall traps. Fonofos seed treatment was also shown to affect selected species. Consideration of the biology of individuals of groups of species provided explanations of why some species such as Nebria brevicollis, Notiophilus spp., Bembidion spp., and Trechus quadristriatus were severely affected by one or other of the chemicals, whereas other species (e.g. Amara spp., Harpalus spp.) were able to survive or recolonise pastures shortly after chemical application. Measurements of elytral and pronotal widths and counts of mature eggs in N. brevicollis, which was trapped in reduced numbers over a long period, were made and provided some information about the mode of action of these chemicals.
Arabis mosaic nepovirus coat protein in transgenic tobacco lessens disease severity and virus replication
Authors: BERTIOLI D. J. , COOPER J. I. , EDWARDS M. L. , HAWES W. S. 
Published: February 2008

SummaryTobacco plants expressing the coat protein of a lilac isolate of arabis mosaic virus (ArMV) poorly supported the replication of this virus and did not display any of the signs of systemic invasion produced in their untransformed counterparts or in transgenic plants expressing a different gene (β‐glucuronidase). These effects, were manifest whether the inoculum was virions or RNA. This is the first report of such coat protein protection with a nepovirus.
Restricted virus multiplication in potatoes transformed with the coat protein gene of potato leafroll luteovirus: similarities with a type of host gene‐mediated resistance
Authors: BARKER H. , REAVY B. , KUMAR A. , WEBSTER K. D. , MAYO M. A. 
Published: February 2008

SummaryPlants of two potato cultivars were transformed with disarmed Agrobacterium rumefaciens (LBA4404) containing a binary expression vector. The vector contained sequences that encode the coat protein of potato leafroll luteovirus (PLRV) under the control of the 35s promoter of cauliflower mosaic virus. RNA transcripts from the integrated viral gene were readily detected in the transgenic plants. PLRV coat protein was detected in only some of these plants when using sensitive immunoblotting techniques. Tubers were collected from transgenic plants that became infected following inoculation either by viruliferous aphids or by grafting with scions from infected plants. When these tubers were used to grow plants with secondary infection, less virus accumulated in each plant of some transgenic lines than in control plants. The PLRV concentration, estimated at different sampling times, in plants of cv. Désirée (transgenic line B1) and cv. Pentland Squire (transgenic line C4) was about 15% and 30% respectively of that in control plants. Among a number of conventionally‐bred clones of potato, some were resistant to virus multiplication and were found to accumulate little virus. The coat protein‐mediated resistance in transgenic potato plants is discussed in relation to the conventional gene‐mediated resistance found in some breeding clones.
Sugar‐beet treatments, water supply and depth of sowing
Authors: DURRANT M. J. , MASH S. J. 
Published: February 2008

SummaryWith variation in rainfall patterns, evaporation, seedbed soil structure and depth of sowing, sugar‐beet seed and seedlings can be subjected to damaging extremes of water availability. Under controlled conditions, seed given progressively longer pre‐sowing treatments (steeped for 12 h at 25°C or advanced for 4 days at 25°C) was more tolerant of non‐optimal conditions than seed given a brief steep (20 min at 15°C). The prolonged steep treatment accelerated emergence and increased establishment (3% on average) in the field, compared with the brief steep. Advanced seed consistently gave the quickest emergence, produced as many plants as the prolonged steep, and was less affected by depth of sowing so its introduction should improve the establishment phase of the sugar‐beet crop.
The effect of galls induced by the gall fly Procecidochares utilis on vegetative growth and reproductive potential of crofton weed, Ageratina adenophora
Authors: ERASMUS D. J. , BENNETT P. H. , STADEN J. VAN 
Published: February 2008

SummaryReproductive potential and vegetative growth of Ageratina adenophora (Spreng.) K. & R. (crofton weed) were measured under ambient conditions to evaluate the efficacy of the gall fly, Procecidochares utilis Stone as a biocontrol agent for this weed. Galls induced by the fly resulted in the production of underdeveloped capitula and a reduction in the number of capitula and filled achenes per capitulum. Galling had no effect on subsequent germination of the seed produced. Where vegetative growth was concerned the effect of galling ranged from a temporary cessation of growth to death of stems above the gall. Although galling promoted production of side shoots, the dry mass of above‐ground material was markedly reduced.
Epidemiology of tobacco leaf curl virus in India
Authors: VALAND G. B. , MUNIYAPPA V. 
Published: February 2008

SummaryThe incidence of disease caused by tobacco leaf curl geminivirus (TbLCV) in ten tobacco growing areas of India ranged from 1.2% to 77%. The highest incidence of disease was observed in Andhra Pradesh (77%) followed by Gujarat (59%), Karnataka (17%), Bihar (11.6%) and West Bengal (5.4%). Under field conditions, an average of 32 adult whiteflies (Bemisia tabaci) per plant were recorded in Andhra Pradesh followed by Gujarat (20), Karnataka (12), Bihar (8) and West Bengal (5). In sequential sowings at Bangalore, all the plants were infected within 90 days in plots planted from February to June. Infection in plots planted later was progressively less. There was a positive correlation between whitefly catches and the final incidence of leaf curl disease in plantings. TbLCV was transmitted by Bemisia tabaci to 35 plant species, including Beta vulgaris, Capsicum annuum, Carica papaya, Cymopsis tetragonoloba, Lycopersicon esculentum, Sesamum indicum, Phaseolus vulgaris and Petunia hybrida. Forty five TbLCV isolates from different parts of India induced four distinct types of symptoms on tobacco cultivars Samsun and Anand 119. Group 1 isolates caused severe curling and cup‐shaped enations; group II isolates induced pale green leaves, pit‐like depressions and thorny enations: group III isolates caused leathery leaves, narrow and tiny protruding enations between the veins, and group IV isolates induced irregular thickening and swelling of veins and green flap‐like enations on veins. Nylon net covers protected tobacco seedlings in nursery beds for 45 days. Ricinus communis and Helianthus annuus sown around the tobacco nursery bed as barrier crops attracted adult whiteflies and decreased the number found on tobacco.
The transmissibility of a potyvirus by an aphid vector: reliability of measurements under controlled conditions
Authors: LABONNE G. , LUPOLI R. , QUIOT J. ‐B. , YVON M. 
Published: February 2008

SummaryReproducibility of measurements of the transmission rate of a given potyvirus by a given aphid vector was assessed using a standardised transmission procedure. The plant‐virus‐vector system studied was: Cucurbita pepo ‐ Papaya ringspot virus ‐ Aphis gossypii.Several elements concerning the rearing and handling of the aphids were analysed. One of these, the climatic conditions under which the aphids were reared, influenced the transmission rate of the virus. Six trials were carried out to measure the rate of transmission of the virus from a defined leaf surface area. The measurements appeared to be reliable. A two year experiment was carried out to compare transmission rates at different dates. Although strong variations were observed in some source plants, the transmission rates obtained for samples of 10 source plants were stable, with a 10% coefficient of variation.The results show that transmissibility of the virus is a stable property which is independent of the trial date. They are discussed in relation to standardised elements of the transmission process.
Comparative transmission of, and varietal reaction to, three isolates of rice tungro virus disease
Authors: DAHAL G. , DASGUPTA I. , LEE G. , HULL R. 
Published: February 2008

SummaryComparative transmission by leafhoppers of three tungro isolates obtained from the Philippines, India and Malaysia, and of an infectious clone of the Philippine isolate of rice tungro bacilliform virus (RTBV) by agroinoculation, was conducted on 12 rice cultivars. The symptoms, including height of inoculated plants were recorded and the efficiency of RTBV and rice tungro spherical virus (RTSV) transmission was determined by enzyme‐linked immunosorbent assay. In most cases, the reduction of height and leaf symptoms of plants infected with RTBV and/or RTSV by the three isolates were similar in any given cultivar. On cultivar ASD7, the Malaysian isolate showed more severe yellow orange leaf discolouration symptoms than the Indian isolate which in turn had more severe leaf discolouration than the Philippine isolate. On the other hand, cultivars ASD 7 and Ptb 18 produced the most severe yellow orange leaf discolouration when agroinoculated with an infectious RTBV clone of the Philippine isolate. There was some variation in the transmission profile of the two tungro viruses among the three isolates. However, there was no one clear set of characteristics by which one could use cultivars to distinguish isolates.The amount of viral DNA in agroinfected plants of cultivars Utri merah, Balimau putih, Utri Rajapan and ARC 11554 was low, while the amount was high in cultivars TN1, ASD7, Ptb 18 and TKM 6. There was high correlation between the amount of viral coat protein by ELISA and viral nucleic acid by DNA hybridisation on 10 agroinoculated rice cultivars; this might indicate that similar proportions of the total RTBV DNA are encapsidated in each cultivar.
Interactions of the Solanum spp. of the Etuberosa group and nine potato‐infecting viruses and a viroid
Authors: VALKONEN J. P. T. , BRIGNETI G. , SALAZAR L. F. , PEHU E. , GIBSON R. W. 
Published: February 2008

SummaryAll 26 accessions of Solanum brevidens, one accession of S. etuberosum and one accession of S. fernandezianum tested were all extremely resistant to potato leafroll virus (PLRV) and potato viruses Y (PVY) and A (PVA). S. brevidens and S. etuberosum were also resistant to Andean potato mottle virus (APMV) and moderately resistant to potato virus X (PVX), whereas S. fernandezianum was susceptible to these viruses. Additionally, S. brevidens was resistant to sap‐inoculated potato viruses M (PVM) and S (PVS). All the Etuberosa accessions were susceptible by graft‐inoculation to PVM, PVS, potato virus T (PVT) and Andean potato latent virus (APLV). Infections by the above mentioned viruses were symptomless in all of the Etuberosa spp. S. etuberosum and S. fernandezianum were infected by mechanical inoculation with potato spindle tuber viroid, S. etuberosum developing severe stunting and leaf‐curl symptoms, but S. brevidens was infected only by graft‐inoculation.The genes conferring resistance to PVY and PVX in S. brevidens and S. etuberosum appeared to be different from those currently utilised by plant breeders.
Growth and development of Avena fatua (Wild‐oat) in the field
Authors: COUSENS R. , WEAVER S. E. , PORTER J. R. , ROONEY J. M. , BUTLER D. R. , JOHNSON M. P. 
Published: February 2008

SummaryThe growth and development of field‐grown Avena fatua plants were studied for autumn and spring sowings in two consecutive years. The duration of various growth stages from sowing until anthesis was quantified in terms of thermal time (accumulated degree days) or photothermal time (degree days modified by photoperiod). Base temperatures and photoperiods for developmental phases were estimated as those which minimised the coefficient of variation among sowing dates. Relationships were derived between leaf emergence, canopy height, plant leaf area, and photothermal time. Stem extension and flowering occurred earlier in autumn‐sown plants than spring‐sown plants. Autumn‐sown plants produced more leaves on the main stem, and had greater leaf area and above‐ground biomass at anthesis than spring‐sown plants.
Postharvest biological control of Penicillium digitatum decay on citrus fruit by Bacillus pumilus
Authors: HUANG YONG , WILD B. L. , MORRIS S. C. 
Published: February 2008

SummaryA new antagonist/pathogen combination is reported, with Bacillus pumilus showing strong antagonistic activity against Penicillium digitatum. B. pumilus (1.6 × 1010 to 1.6 × 1012*cfu ml‐1) gave significant control of P. digitatum infection in Valencia orange, which was as effective as imazalil (500 μg ml‐1) and was significantly better than benomyl treatment (500 μg ml‐1). When lower concentrations of B. pumilus (1.9 × 107 to 1.9 × 109 cfu ml‐1) were tested on Washington Navel orange and Lisbon lemon fruit, the antagonist caused significant control of P. digitatum infection at two inoculum levels (6.5 × 104 and 6.5 × 105 spores ml‐5). Concentrations of both the pathogen and the antagonist affected the biocontrol effect.
Transcription amplification of polymerase chain reaction products of bean yellow mosaic virus RNA extracted from gladioli corms
Authors: ROSNER ARIE , STEIN ADINA , LEVY SAMUEL 
Published: February 2008

SummaryThe RNA genome of bean yellow mosaic virus (BYMV) was detected in gladioli corms by reverse transcription and polymerase chain reaction (PCR). However, a positive signal was not obtained from some infected corms because the virus concentration was below the sensitivity limits of PCR. Virus was detected in these corms by using a modified protocol in which transcription of the PCR products by T7 RNA polymerase yielded an additional 10‐ to 100‐fold signal amplification.The relative concentrations of BYMV in gladioli corms were evaluated using PCR. Virus accumulation in corms was found to be a 100 times lower than in leaves, and be within the range of picogram quantities of viral RNA per gram fresh weight of corm tissue.
Pathogenicity of three RPV isolates of Barley Yellow Dwarf Virus on barley, wheat and wheat alien addition lines
Authors: BANKS P. M. , WATERHOUSE P. M. , LARKIN P. J. 
Published: February 2008

SummaryBarleys with and without the Yd2 resistance factor, wheat alien addition stocks with other barley yellow dwarf virus (BYDV) resistance factors and true wheats were challenged with three Australian isolates of BYDV‐RPV. Yd2 resistance was effective against two of the BYDV‐RPV isolates and inoculated barleys which carry Yd2 did not develop BYD symptoms and shoot growth was not affected. However, barleys with Yd2 were susceptible to the third BYDV‐RPV isolate. All barley lines inoculated with the third virus isolate developed typical BYD symptoms (yellowing), shoot growth was reduced compared to uninfected controls and virus titres determined by ELISA were high and similar in barleys with and without Yd2. In contrast, resistances from Thinopyrum intermedium and Agropyron pulcherrimum in wheat backgrounds were effective against all three BYDV‐RPV isolates. Shoot growth of inoculated plants with either of these resistance factors did not differ from uninfected controls and virus titres determined by ELISA were very low.
Accumulation of potato virus Y is enhanced in Solatium brevidens also infected with tobacco mosaic virus or potato spindle tuber viroid
Authors: VALKONEN JARI P. T. 
Published: February 2008

SummaryThe accumulation of potato virus Y˚(PVY˚) and potato leaf roll virus (PLRV) was studied in plants of Solanum brevidens co‐infected with each of six viruses or a viroid. Virus could not be detected by ELISA in plants of S. brevidens infected solely with PVY. However, accumulation of PVY was increased c. 1000‐fold in plants doubly infected with tobacco mosaic virus or potato spindle tuber viroid (PSTVd). PVY titres in doubly infected plants of S. brevidens were between 1% and 0.1% of those found in the PVY‐susceptible interspecific Solanum hybrid DTO‐33. Double infections of 5. brevidens by PVY and alfalfa mosaic virus or potato viruses M, S, T or X did not significantly enhance PVY accumulation. Accumulation of PLRV was not enhanced in plants co‐infected with any of the six viruses or PSTVd.
Spread of potato leafroll virus is decreased from plants of potato clones in which virus accumulation is restricted
Authors: BARKER H. , WOODFORD J. A. T. 
Published: February 2008

SummaryTubers of eight potato clones infected with potato leafroll luteovirus (PLRV) were planted as ‘infectors’ in a field crop grown, at Invergowrie, of virus‐free potato cv. Maris Piper in 1989. The mean PLRV contents of the infector clones, determined by enzyme‐linked immunosorbent assay (ELISA) of leaf tissue, ranged from c. 65 to 2400 ng/g leaf. Myzus persicae colonised the crop shortly after shoot emergence in late May and established large populations on all plants, exceeding 2000/plant by 27 June. Aphid infestations were controlled on 30 June by insecticide sprays. Aphid‐borne spread of PLRV from plants of the infector clones was assessed in August by ELISA of foliage samples from the neighbouring Maris Piper ‘receptors’. Up to 89% infection occurred in receptor plots containing infector clones with high concentrations of PLRV. Spread was least (as little as 6%) in plots containing infectors in which PLRV concentrations were low. Primary PLRV infection in guard areas of the crop away from infectors was 4%. Some receptor plants became infected where no leaf contact was established with the infectors, suggesting that some virus spread may have been initiated by aphids walking across the soil.
Distribution and prevalence of the entomopathogenic nematode Steinernema feltiae in Scotland
Authors: BOAG B. , NEILSON R. , GORDON S. C. 
Published: February 2008

SummaryThe distribution of insect parasitic nematodes in Scotland was investigated between April 1988 and April 1989 using the wax moth, Galleria mellonella, larvae as bait. Of the 1014 samples examined only 2.2% were found to be positive and all the nematodes recovered and identified belonged to the one species Steinernema feltiae. A more detailed investigation into the distribution of S. feltiae in a 1 ha block indicated that it had a very aggregated distribution.