Spotlight On...
The Luteoviridae.
The Luteoviridae family contains a number of economically important viruses, which attack food crops, including the barley yellow dwarf viruses. This month's feature highlights a book edited by H. G. Smith and H. Barker, which forms a comprehensive review of the current knowledge of luteoviruses:
- The Luteoviridae
Edited by H. G. Smith and H. Barker.
The Luteoviridae is currently Book of the Month at the CABI Publishing Online Bookshop, where a full-text version can be read on-line and the book can be ordered at a 20% discount. Details of the following books are also available at the Online Bookshop:
- Viruses of Plants
A. Brunt, K. Crabtree, M. Dallwitz, A. Gibbs and L. Watson.
- The Gene-for-Gene Relationship in Plant-Parasite Interactions
Edited by I. R. Crute, E. B. Holub and J. J. Burdon.
- The Potyviridae
D. D. Shukla, C. W. Ward and A. A. Brunt.
- Nematode Vectors of Plant Viruses
C. E. Taylor and D. J. F. Brown
A selection of abstracts on Luteoviridae from the Review of Plant Pathology is given below.
Related items included in PEST CABWeb®:
TI: Effects of beet western yellows virus on growth and yield of oilseed rape (Brassica napus).
AU: Jay, C. N.\ Rossall, S.\ Smith, H. G.
JN: Journal of Agricultural Science
YR: 1999
VL: 133
NO: 2
PP: 131-139
LA: En
MS: 22 ref.
AA: IACR-Broom's Barn, Higham, Bury St Edmunds, Suffolk IP28 6NP, UK.
AB: Field trials were undertaken in Suffolk, UK, in commercial crops of autumn-sown oilseed rape cv. Capricorn during 1993/94 and cv. Apex in 1994/95. Plots were artificially infected with beet western yellows virus (BWYV) using viruliferous Myzus persicae, giving 73 to 94% infection. Control plots had natural infections ranging from 0 to 17.8%. Destructive plant samples were taken from each of the infected and control plots throughout the seasons for growth analyses, and final yields were measured on 44 m2 areas combine harvested from each plot. The seed yields of infected plots were 26 and 11% lower than control plots in 1994 and 1995 respectively (P<0.001). Harvested seed yields were shown to be inversely proportional to the area of the plot that was inoculated with BWYV. Infection significantly lowered the oil content in 1995 from 47.9 to 46.8% (P<0.001), and increased glucosinolate levels from 16.12 to 18.37 µmol/g (P<0.01). BWYV caused a significant reduction in plant height and in numbers of primary branches in the effect on the dry weight of the leaves, stalks, racemes and pods at some sample dates in both seasons. Virus-testing of infected plants showed that BWYV was present in the pod wall, the septum and seed coat; 2 of 78 embryo samples also contained virus. It was concluded that BWYV can cause significant yield losses in those years in which there is a high incidence of virus in the overwintered crops.
DE: Brassica\Brassica napus\rape\yellows\yields\Myzus\Myzus persicae\overwintering\yield losses\plant diseases\plant pathogens\plant viruses\UK\crop losses\beet western yellow virus\Luteoviridae\Polerovirus
AN: 0M07901245
TI: The importance of barley yellow dwarf virus (BYDV) infection in spring barley and opportunities to manage the disease.
AU: Carver, M.\ Overthrow, R.\ Lucas, J.\ Phillips, S.
JN: HGCA Project Report
YR: 1999
NO: No. 206
PP: 19 pp.
LA: En
AA: Arable Research Centres, Manor Farm, Lower End, Daglingworth, Nr Cirencester, Gloucestershire GL7 7AH, UK.
AB: Barley yellow dwarf virus (BYDV) is an aphid transmitted disease which can severely reduce the yield of barley. Management techniques to control BYDV infection in autumn sown barley are now well understood and regularly adopted. However BYDV can also cause severe problems in spring sown barley and the full extent of the problem has only been realised since the introduction of varieties possessing tolerance of BYDV infection. Control of BYDV infection primarily revolves around control of the vector, the aphid. As the autumn progresses and temperatures decrease management techniques have been timed to control primary infections (infected aphids flying into crops) before secondary infections (infected aphids moving within crops) develop. Both foliar sprays and seed treatments can be successfully used to control aphids in the winter sown crops. Control in the spring sown barley crop has always been considered to be more difficult. BYDV infections have tended to increase as the spring progresses as temperatures rise thereby encouraging more aphid activity. It has not been considered feasible to use foliar insecticides as a reliable method of control as primary infection will always be taking place as temperatures increase in the spring. However the potential of both BYDV resistance in varieties and the seed treatment imidacloprid in reducing the incidence of BYDV infections in spring sown barley crops were considered to be important and were evaluated in a series of trials conducted over three seasons. Three varieties of spring barley, (two resistant to BYDV - CORK and OPTIC and one susceptible to BYDV - DERKADO) were drilled on two drilling dates at four locations in England. Treatments involving both seed and foliar applied insecticides were compared over the three seasons of the study. BYDV infection levels were heavy in one season but not severe in the other two seasons, and whilst the susceptible variety did exhibit more BYDV infection the differences between varieties were not as marked as had been anticipated. Delaying the drilling date, typically by about one month from March to April had a marked effect on yield the greatest reduction from later drilling being in the season that illustrated the highest BYDV infection levels. Later drillings reduced yields by 14.9% to 37.6% and the overall average over the three seasons of trials was -26.9%. The different combinations of insecticidal seed treatment and foliar insecticide application produced very inconsistent results, and no treatment satisfactorily controlled primary BYDV infections from in flying aphids (Sitobion avenae, Rhopalosiphum padi and Metopolophium dirhodum). The main management techniques to reduce the impact of BYDV infection on spring barley crops would appear to be earlier drilling dates and the use of resistant varieties.
DE: plant diseases\plant pathogens\plant viruses\Hordeum vulgare\barley\viruses\barley yellow dwarf
luteovirus\Luteovirus\Luteoviridae\plant disease control\disease transmission\Aphidoidea\Sitobion avenae\Rhopalosiphum padi\Metopolophium dirhodum\pest control\imidacloprid\insecticides\seed treatment\temperature\varieties\cultivars\vectors\yields\pest resistance\disease resistance\cultural control\cultural methods\sowing date\planting date
GL: UK
AN: 0E08801017\0M07901685\6T01700654
TI: Development and validation of decision support methodology for control of barley yellow dwarf virus.
AU: Harrington, R.\ Mann, J. A.\ Burgess, A. J.\ Tones, S. J.\ Rogers, R.\ Foster, G. N.\ Blake, S.\ Morrison, S. F.\Ward, L.\ Barker, I.\ Morgan, D.\ Walters, K. F. A.
JN: HGCA Project Report
YR: 1999
NO: No. 205
PP: 86 pp.
LA: En
MS: 12 ref.
AA: IACR-Rothamsted, Harpenden, Hertfordshire AL5 2JQ, UK.
AB: The aim of this project was to develop an effective, user-friendly, field specific system for assessing the need to control the aphid vectors of barley yellow dwarf virus (BYDV). The main vectors in the UK are the bird cherry-oat aphid (Rhopalosiphum padi) and the grain aphid (Sitobion avenae). An existing regional scale trapping system was used to assess how many winged aphids carrying the virus enter crops (barley, wheat and oats) in autumn (primary infection). A mathematical model was developed under MAFF funding to capture the effect of weather on the development, reproduction, movement and survival of aphids and this is used to determine how much secondary spread of the virus there has been from the initial foci. The model was tested against independent data collected at three sites in the UK. To assess how regional risk translates to a field-specific risk a major survey was done to examine the characteristics of fields, which make them prone to BYDV problems. The whole system is designed to fit within the DESSAC decision support system.
DE: plant diseases\plant pathogens\plant viruses\barley yellow dwarf luteovirus\Luteovirus\Luteoviridae\Hordeum vulgare\barley\wheat\Triticum aestivum\oats\Avena sativa\plant disease control\disease transmission\plant pests\insect pests\Aphidoidea\Rhopalosiphum padi\Sitobion avenae\trapping\spread\epidemiology\monitoring\models\environmental factors\climatic factors\expert systems
GL: UK
AN: 0E08800998\0M07901679\6T01700660
TI: First records of bean leafroll luteovirus in Australia.
AU: Schwinghamer, M. W.\ Johnstone, G. R.\ Johnston-Lord, C. F.
JN: Australasian Plant Pathology
YR: 1999
VL: 28
NO: 3
PP: 260
LA: En
MS: 2 ref.
AA: NSW Agriculture, RMB 944, Tamworth, New South Wales 2340, Australia.
AB: Bean leafroll virus (BLRV) was shown to infect naturally a range of winter-grown legumes (chickpeas, fababeans, peas, lentils, medics (Medicago polymorpha and M. truncatula) and clovers (Trifolium subterraneum and T. glomeratum)) in northern New South Wales, Australia. Identification was by symptoms, enzyme-linked immunosorbent assays (ELISA), a reverse transcription polymerase chain reaction (RT-PCR) test and transmissibility.
DE: chickpeas\faba beans\peas\lentils\Medicago truncatula\Medicago polymorpha\Trifolium subterraneum\Trifolium glomeratum\Bean leafroll virus\Australia\Luteovirus\legumes\New South Wales\plant diseases\plant pathogens\plant viruses\Fabaceae\Luteoviridae
AN: 0M07900082
TI: A plant and field study of BYDV-PAV and -MAV distribution on maize in France.
FT: Untersuchungen zur Wanderung von BYDV-PAV und -MAV in einzelnen Maispflanzen und in einem Maisfeld in Frankreich.
AU: Haack, L.\ Courbon, R.\ Riault, G.\ Tanguy, S.\ Vilain, D. le\ Henry,M.\ Dedryver, C. A.
JN: Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz
YR: 1999
VL: 106
NO: 3
PP: 297-303
LA: En
LS: de
MS: 15 ref.
AA: INRA, Laboratoire de Zoologie, Domaine de la Motte, 35653 Le Rheu, France.
AB: The distribution of the PAV and MAV strains of barley yellow dwarf luteovirus in maize (cv. Dea) was studied in 1996 and 1997 at plant and field levels at Le Rheu in western France. The distribution of viruses was studied in individual maize plants grown in a glasshouse and inoculated in the laboratory by viruliferous Rhopalosiphum padi (PAV) and Sitobion avenae (MAV). In the first experiment, the influence of the growth stage of maize when inoculated on the success of infection was studied. For both virus strains 100 % infection was obtained in maize plants inoculated at the 2, 4 and 6 leaf stages. The percentage of infection decreased drastically for PAV and more slowly for MAV in plants inoculated at an older stage. In the second experiment the kinetics of PAV and MAV was studied in maize plants inoculated at the 4 leaf stage. PAV was detected more frequently than MAV in roots and both viruses developed mainly in the upper leaves. Leaves 8 and 9 were the most consistently infected by PAV and could be used for field sampling. The distribution of MAV and PAV was studied weekly in a maize field during spring and summer 1997, by regular sampling of several hundreds of plants. The results clearly showed a lack of secondary spread of the viruses: 50-80 % of the plants were infected in a few days following the infestation of the maize crop by the alate aphid vectors in mid-June and this percentage of infected plants remained unchanged during the summer.
DE: plant diseases\plant pathogens\plant viruses\Zea mays\maize\barley yellow dwarf luteovirus\geographical distribution\transmission\strains\Rhopalosiphum padi\Sitobion avenae\insect pests\disease vectors\growth stages\epidemiology\spread
GL: France
AN: 0M07806934\6P01502888\0E08711582
TI: Characterisation of resistance to potato leafroll virus accumulation in Solanum phureja.
AU: Franco-Lara, L.\ Barker, H.
JN: Euphytica
YR: 1999
VL: 108
NO: 2
PP: 137-144
LA: En
MS: 23 ref.
AA: Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
AB: Strong resistance to accumulation of potato leaf roll luteovirus (PLRV) was identified in a clone of the diploid potato species Solanum phureja (cv. Egg Yolk, clone 5010) using a quantitative enzyme-linked immunosorbent assay (ELISA). The resistance is expressed very strongly in leaf tissue (virus could not be detected in leaves of some plants although other tissues were infected) but less strongly in petiole and stem tissue of infected plants. The titre of PLRV in leaves of S. phureja (5010) is approximately 2%, or less, of the titre in S. tuberosum cv. Maris Piper. The pattern of virus accumulation in different tissues of S. phureja (5010) and the distribution of virus-infected cells in phloem bundles suggest that this resistance is different to a similar form of resistance to PLRV accumulation previously identified in clones of Solanum tuberosum. Plants of S. phureja (5010) were transformed with the coat protein gene of potato leaf roll virus (PLRV). Transgenic lines of S. phureja (5010) expressing transgene RNA transcript were no more resistant to aphid-borne infection with PLRV or to virus accumulation than were non-transgenic lines.
DE: potato leaf roll luteovirus\Solanum\Solanum phureja\viruses\assays\clones\ELISA\phloem\Solanum tuberosum\transgenic plants\coat proteins\genetic transformation\genetic engineering\gene expression\Aphididae\disease vectors\plant viruses\disease resistance\plant pathogens\wild relatives\Luteoviridae\Polerovirus\plant diseases
AN: 7B01105559\6C00802228\7K02401420\0P06912466
TI: Evaluation of barley yellow dwarf virus tolerance: a controlled field system compared with a molecular marker test.
AU: Steyer, S.\ Léal, C.\ Grégoire, D.\ Froidmont, D. de
JN: Zeitschrift für Pflanzenkrankheiten und Pflanzenschutz
YR: 1999
VL: 106
NO: 5
PP: 553-555
LA: En
LS: de
MS: 3 ref.
AA: Centre de Recherches Agronomiques, Département de Lutte Biologique et de Ressources Phytogénétiques, Chemin de Liroux, B-5030 Gembloux, Belgium.
AB: For the evaluation of BYDV tolerance, a controlled field system was developed to test barley lines from a breeding programme. ELISA tests confirmed the presence of the virus in the plants. Visual assessments were made during the spring to select tolerant F4 generations. A PCR marker was used to discriminate between Yd2 and non-Yd2 barley plants. In parallel trials, plants were analysed for the presence of the Yd2 gene. Results obtained with the controlled field systems were compared with the PCR test. The cost and time taken were evaluated for each method and the breeding possibilities offered with the combined methods are discussed.
DE: Hordeum vulgare\barley\ELISA\polymerase chain reaction\plant diseases\plant pathogens\plant viruses\barley yellow dwarf luteovirus\disease resistance\testing\molecular biology\Luteoviridae
TI: In situ localization of barley yellow dwarf virus-PAV 17-kDa protein and nucleic acids in oats.
AU: Nass, P. H.\ Domier, L. L.\ Jakstys, B. P.\ D'Arcy, C. J.
JN: Phytopathology
YR: 1998
VL: 88
NO: 10
PP: 1031-1039
LA: En
MS: 37 ref.
AA: University of Illinois, Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana 61801, USA.
AB: Barley yellow dwarf virus strain PAV (BYDV-PAV) RNA and the 17-kDa protein were localized in BYDV-PAV-infected oat (Avena byzantina) cells using in situ hybridization and in situ immunolocalization assays, respectively. The in situ hybridization assay showed labelling of filamentous material in the nucleus, cytoplasm, and virus-induced vesicles with both sense and antisense nucleic acid probes, suggesting that the filamentous material found in BYDV-PAV-infected cells contains viral RNA. BYDV-PAV negative-strand RNA was detected before virus particles were observed, which indicates that RNA replication is initiated before synthesis of viral coat protein in the cytoplasm. The 17-kDa protein was associated with filamentous material in the cytoplasm, nucleus, and virus-induced vesicles. The labelling densities observed using antibodies against the 17-kDa protein were similar in the nucleus and cytoplasm. No labelling of the 17-kDa protein was observed in plasmodesmata, but filaments in the nuclear pores occasionally were labelled. Since BYDV-PAV RNA and 17-kDa protein colocalized within infected cells, it is possible that single-stranded viral RNA is always associated with the 17-kDa protein in vivo. The 17-kDa protein may be required for viral nucleic acid filaments to traverse the nuclear membrane or other membrane systems.
DE: oats\Avena byzantina\barley yellow dwarf luteovirus\hybridization\RNA\plant viruses\plant pathogens\proteins\Luteovirus\Luteoviridae\plant diseases\molecular genetics\infection\pathogenicity
TI: Transformation of tobacco and potato with cDNA encoding the full-length genome of potato leafroll virus: evidence for a novel virus distribution and host effects on virus multiplication.
AU: Franco-Lara, L. F.\ McGeachy, K. D.\ Commandeur, U.\ Martin, R. R.\ Mayo, M. A.\ Barker, H.
JN: Journal of General Virology
YR: 1999
VL: 80
NO: 11
PP: 2813-2822
LA: En
MS: 32 ref.
AA: Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
AB: A full-length cDNA copy of the genome of potato leafroll virus (PLRV) was introduced into the genome of tobacco and potato plants by Agrobacterium tumefaciens-mediated transformation. Transgenic lines were obtained in which the transgene was readily detected by PCR with DNA extracted from T1 tobacco seedlings and clonally multiplied potato plants. PLRV-specific genomic and sub-genomic RNAs, coat protein antigen and virus particles were detected in transgenic plants. Aphids fed on the transgenic tobacco plants readily transmitted PLRV to test plants. Infected transgenic tobacco plants, like non-transgenic (WT) PLRV-infected plants, displayed no symptoms of the infection but transgenic plants of potato were severely stunted. In parallel tests, the mean PLRV titres in WT tobacco plants and transgenic tobacco plants were 600 and 630 ng virus/g leaf, respectively, although differences in PLRV titres among transgenic plants were much greater than those among infected WT plants. In similar tests with potato, the mean PLRV titre of WT plants was 50 ng virus/g leaf whereas higher concentrations (up to 3400 ng virus/g leaf) accumulated in transgenic potato plants. In tissue prints of stems, PLRV was detected in similar proportions of phloem cells in transgenic and infected WT plants. In transgenic tobacco and potato plants, but not in infected WT plants, a few stem epidermal cells also contained virus. From tissue prints of transgenic tobacco leaves, it was estimated that approx 1 in 40000 mesophyll cells contained virus, but in transgenic potato, a greater proportion of mesophyll cells was infected.
DE: complementary DNA\genomes\potato leafroll virus\tobacco\Nicotiana\Aphidoidea\DNA\transgenics\transgenic plants\luteoviridae\polerovirus\plant diseases\plant pathogens\plant viruses\potatoes\Solanum tuberosum\genetics\Nicotiana tabacum\genetic transformation\gene expression
TI: Role of the beet western yellows virus readthrough protein in virus movement in Nicotiana clevelandii.
AU: Mutterer, J. D.\ Stussi-Garaud, C.\ Michler, P.\ Richards, K. E.\ Jonard, G.\ Ziegler-Graff, V.
JN: Journal of General Virology
YR: 1999
VL: 80
NO: 10
PP: 2771-2778
LA: En
MS: 24 ref.
AA: Institut de Biologie Moléculaire des Plantes du CNRS et de l'Université Louis Pasteur, 12 rue du Général Zimmer, Strasbourg 67084 cedex, France.
AB: The readthrough domain (RTD) of the minor BWYV capsid protein P74 is required for efficient virus accumulation in Nicotiana clevelandii. Experiments were carried out to determine if the low virus titres observed following agro-inoculation of whole plants with certain RTD mutants are due to a defect in virus multiplication in the nucleate cells of the phloem compartment or to inefficient virus movement to new infection sites. Immuno-localization of wild-type and an RTD-null mutant virus in thin sections of petioles and in phloem cells of leaf lamina, as well as electron microscopy observations, were all consistent with the conclusion that the RTD is not essential for efficient virus multiplication in the nucleate phloem cells but intervenes in virus movement to increase the rate at which new infection foci are established and expand.
DE: Nicotiana\Nicotiana clevelandii\plant diseases\plant pathogens\plant viruses\beet western yellows luteovirus\Luteoviridae\Polerovirus\movement\coat proteins
AN: 0M07901394
TI: Influence of Neotyphodium lolii and barley yellow dwarf virus, individually and combined, on the growth of Lolium perenne.
AU: Hesse, U.\ Latch, G. C. M.
JN: Australasian Plant Pathology
YR: 1999
VL: 28
NO: 3
PP: 240-247
LA: En
MS: 27 ref.
AA: Institut für und Pflanzenbau, Lehrgebiet Saatgutwirtschaft, Martin-Luther-Universität Halle-Wittenberg, 06099 Halle, Germany.
AB: The effect of infection by either of 2 strains of the endophyte Neotyphodium lolii with or without infection by barley yellow dwarf virus (BYDV) on the growth of 8 perennial ryegrass genotypes was investigated in a greenhouse trial. Herbage production was significantly influenced by plant genotype. Infection with BYDV reduced dry matter and tiller production of most perennial ryegrass plants and although there was no significant plant genotype x virus interaction, the genotypes differed in their response to virus infection. Infection with endophyte induced an increase in plant dry weight of 42% in one genotype, whereas the others were not significantly affected. The presence of BYDV did not influence production of the alkaloids ergovaline, lolitrem B or peramine, nor was there a significant interaction between the 2 strains of endophyte and the virus. However, with some genotypes virus infection masked the effect of endophyte on the dry matter production of plants.
DE: Lolium\Lolium perenne\growth\plant diseases\plant pathogens\plant viruses\alkaloids\endophytes\Luteovirus\Luteoviridae\barley yellow dwarf luteovirus\Neotyphodium lolii\mixed infections\varietal reactions\crop losses
AN: 0M07900174
TI: Primary and secondary structural elements required for synthesis of barley yellow dwarf virus subgenomic RNA1.
AU: Koev, G.\ Mohan, B. R.\ Miller, W. A.
JN: Journal of Virology
YR: 1999
VL: 73
NO: 4
PP: 2876-2885
LA: En
MS: 49 ref.
AA: Plant Pathology Department, 351 Bessey Hall, Iowa State University, Ames, IA 50011-1020, USA.
AB: Barley yellow dwarf virus (BYDV) generates 3 3’-coterminal subgenomic RNAs (sgRNAs) in infected cells. The promoter of sgRNA1 is a putative hot spot for RNA recombination in luteovirus evolution. The sgRNA1 transcription start site was mapped previously to either nucleotide 2670 or nucleotide 2769 of BYDV genomic RNA (gRNA) in 2 independent studies. Data presented supports the former initiation site. The boundaries of the sgRNA1 promoter map between nucleotides 2595 and 2692 on genomic RNA. Computer prediction, phylogenetic comparison, and structural probing revealed 2 stem-loops (SL1 and SL2) in the sgRNA1 promoter region on the negative strand. Promoter function was analysed by inoculating protoplasts with a full-length infectious clone of the BYDV genome containing mutations in the sgRNA promoter. Because the promoter is located in an essential coding region of the replicase gene, it was duplicated in a nonessential part of the genome from which a new sgRNA was expressed. Mutational analysis revealed that secondary structure, but not the nucleotide sequence, was important at the base of SL1. Regions with both RNA primary and secondary structural features that contributed to transcription initiation were found at the top of SL1. Primary sequence, but not the secondary structure, was required in SL2, which includes the initiation site. Disruption of base pairing near the sgRNA1 start site increased the level of transcription 3- to 4-fold.It is proposed that both primary and secondary structures of the sgRNA1 promoter of BYDV play unique roles in sgRNA1 promoter recognition and transcription initiation.
DE: genomes\mutations\nucleotides\phylogeny\protoplasts\recombination\RNA\transcription\barley yellow dwarf luteovirus\plant pathogens\plant viruses\molecular genetics\synthesis\replication\luteoviridae\luteovirus\mapping
AN: 0M07900773
TI: Nutrient solution nitrogen form and barley yellow dwarf virus disease tolerance in oat and wheat.
AU: Riedell, W. E.
JN: Journal of Plant Nutrition
YR: 1999
VL: 22
NO: 10
PP: 1577-1587
LA: En
MS: 20 ref.
AA: USDA-ARS, NPA, Northern Grain Insects Research Laboratory, 2923 Medary Avenue, Brookings,
SD 57006, USA.
AB: A greenhouse study was conducted to determine how growth, grain yield, and yield components of oat (Avena sativa) and wheat (Triticum aestivum) plants given nutrient solutions containing different ratios of NO3-N to NH4-N would react to barley yellow dwarf virus (BYDV) infection. Fifteen-day-old seedlings (2nd leaf stage) were either infected with BYDV (PAV strain) or left uninfected. Nutrient solution treatments (started 19 days after germination) provided three ratios of NO3-N to NH4-N (100% NO3, 50:50 NH4:NO3, or 100% NH4) for a 30-day period, after which plant height and tillers plant(-1) were measured. Oat and wheat plants given NH4 had fewer tillers than plants given the other nutrient solution treatments. BYDV-infected oat and wheat plants were shorter than uninfected plants. All pots then received NO3 nutrient solution until plant maturity, after which days to anthesis, primary tiller height,grain yield and yield components were measured. In the NH4 nutrient solution treatments, BYDV infection significantly reduced and primary tiller height in wheat. These same measures were not significantly affected by BYDV infection in the NO3 or NH4NO3 nutrient solution treatments. There were no other significant nutrient solution by BYDV infection interactions for any other dependent variable measured. Nutrient solution treatments had no significant effect on grain yield, but BYDV infection reduced grain yield by 45% in oat and 46% in wheat. It is concluded that nutrient solution N form interacted with BYDV infection to alter disease tolerance in oat (kernel weight) and wheat (primary tiller height), but these alterations had no effect in ameliorating grain yield loss caused by BYDV disease.
DE: plant viruses\wheat\Triticum aestivum\barley yellow dwarf luteovirus\oats\Avena sativa\plant nutrition\mineral nutrition\nitrogen\ammonium nitrogen\nitrate nitrogen\tillering\yield components\crop yield\yield losses\plant pathogens\plant diseases\luteoviridae\luteovirus
AN: 0Q05208747\0M07900846\6T01700229
TI: Reduction of yield components by barley yellow dwarf infection in susceptible winter wheat and winter barley in Virginia.
AU: Herbert, D. A., Jr.\ Stromberg, E. L.\ Chappell, G. F.\ Malone, S. M.
JN: Journal of Production Agriculture
YR: 1999
VL: 12
NO: 1
PP: 105-109
LA: En
MS: 11 ref.
AA: Tidewater Agric. Res. and Ext. Cent., 6321 Holland Rd., Suffolk, VA 23437, USA.
AB: Five field studies were conducted during 1990-93 at two locations in eastern Virginia to determine the effect of naturally occurring barley yellow dwarf virus (BYDV) infection on yield components of susceptible winter barley (Hordeum vulgare) cv. Barsoy and susceptible wheat (Triticum aestivum) cv. Wakefield. At each study site, yield components were compared for grain harvested from 25 disease loci and 25 adjacent asymptomatic areas. Rhopalosiphum padi and Sitobion avenae aphid populations were monitored weekly by visual inspection of plant leaves and stems. Aphid numbers were low in all studies, with only one site exceeding the economic threshold of 15 aphids/row foot at any time during the season. The BYDV, PAV strain, was present in all five studies; the MAV strain was present at only one location in 1990-91. Autumn infection was predominant and occurred in all studies, with plants showing typical disease symptoms. Symptoms consistent with spring infection were observed in only one study. With few exceptions, autumn infection significantly reduced tiller height, head number, seed number, seeds per head, 1000-seed weight and yield. Yield components were not equally affected. Seed number, seeds per head and yield were reduced the most, by 28%, 22%, and 34%, respectively, compared with only about a 5 to 13% reduction in the other components. Spring infection significantly reduced number of seed per head and 1000-seed weight, but not the other yield components.
DE: Hordeum vulgare\barley\Virginia\USA\wheat\Triticum aestivum\yield components\economic thresholds\grain\Hordeum\Rhopalosiphum\Rhopalosiphum padi\seed weight\Sitobion\Sitobion avenae\symptoms\tillers\Triticum\plant viruses\monitoring\transmission\insect pests\barley yellow dwarf luteovirus\diseases\Luteoviridae\Luteovirus\plant pathogens\plant diseases\plant viruses
GL: USA\Virginia
AN: 0Q05206309\6T01603939\0E08710530\0M07900008
TI: Are there risks associated with transgenic resistance to luteoviruses?
AU: Miller, W. A.\ Koev, G.\ Mohan, B. R.
JN: Plant Disease
YR: 1997
VL: 81
NO: 7
PP: 700-710
LA: En
MS: 82 refs.
AA: Plant Pathology Department, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA.
AB: The potential risks associated with transgenic resistance to luteoviruses are discussed with particular reference to comparisons of luteoviral genome sequences, an understanding of the viral replication mechanisms, observations of interactions of luteoviruses with each other and with their hosts and cross-hybridization between luteovirus host plants and related weeds. Three categories involving risk are reviewed: (1) interactions that do not involve any genomic rearrangements between the transgene product and an invading virus, (2) recombination between the transgene and theinvading virus that can create new strains or viruses, (3) the potential escape of the transgene via pollen to weed species related to the transgenic host.
DE: plant diseases\plant pathogens\plant viruses\luteoviruses\disease resistance\molecular genetics\genetic transformation\replication\hybridization\transgenic plants\recombination\reviews\crops\genetic engineering\resistance
AN: 0M07702830\0P06803370\0W04701742
TI: Extreme reduction of disease in oats transformed with the 5’ half of the barley yellow dwarf virus-PAV genome.
AU: Koev, G.\ Mohan, B. R.\ Dinesh-Kumar, S. P.\ Torbert, K. A.\ Somers, D. A.\ Miller, W. A.
JN: Phytopathology
YR: 1998
VL: 88
NO: 10
PP: 1013-1019
LA: En
MS: 49 ref.
AA: Plant Pathology Department, Iowa State University, 351 Bessey Hall, Ames 50011-1020, USA.
AB: Oat plants were transformed with the 5’ half of the barley yellow dwarf viruse (BYDV) strain PAV genome, which includes the RNA-dependent RNA polymerase gene. In experiments on T2- and T3-generation plants descended from the same transformation event, all BYDV-inoculated plants containing the transgene showed disease symptoms initially, but recovered, flowered, and produced seed. In contrast, all but one of the BYDV-PAV-inoculated nontransgenic segregants died before reaching 25 cm in height. Although all of the recovered transgenic plants looked similar, the amount of virus and viral RNA ranged from substantial to undetectable levels. Thus, the transgene may act either by restricting virus accumulation or by a novel transgenic tolerance phenomenon. This work demonstrated a strategy for genetically stable transgenic resistance to BYDVs that should apply to all hosts of the virus.
DE: genomes\oats\Avena sativa\barley yellow dwarf luteovirus\hosts\RNA\RNA polymerase\symptoms\transformation\transgenics\transgenic plants\plant viruses\plant pathogens\Luteovirus\disease resistance
TI: Barley yellow dwarf virus RNA requires a cap-independent translation sequence because it lacks a 5’ cap.
AU: Allen, E.\ Wang ShanPing\ Miller, W. A.
JN: Virology (New York)
YR: 1999
VL: 253
NO: 2
PP: 139-144
LA: En
MS: 23 ref.
AA: Plant Pathology Department, Genetics and MCDB Programs, Iowa State University, Ames, IA 50011, USA.
AB: Functional and physical evidence is presented to show that barley yellow dwarf luteovirus (BYDV) RNA from virions is unmodified at its 5’ terminus, having neither a genome-linked protein nor a 5’ cap. It is also shown that a 3’ translation enhancer (3’ TE), located near the 3’ end of BYDV RNA, is required for translation of the viral genome and thus for viral replication.
DE: RNA\translation\barley yellow dwarf luteovirus\plant pathogens\plant viruses\molecular genetics\nucleotide sequences\Luteovirus
AN: 0M07805341
TI: RAPD marker of resistance gene to strain GPV of BYDV in wheat addition line Z1.
AU: Sun XiaoPing\ Qian YouTing\ Zhou GuangHe
JN: Acta Phytopathologica Sinica
YR: 1999
VL: 29
NO: 1
PP: 37-40
LA: Ch
LS: en
MS: 6 ref.
AA: Institute of Plant Protection, CAAS, Beijing 100094, China.
AB: The wheat-Elytrigia intermedia [Elymus hispidus] addition line Z1 was identified as highly resistant to strain GPV of barley yellow dwarf luteovirus (BYDV) which only exists in China. The genomes of resistant lines and susceptible lines were analysed by RAPD using 104 random primers. It was found that primer OPS-16 can amplify a specific 1.7 kb fragment from the genome of Z1. When Z1, Zhong7902, Elytrigia intermedia and Zhong5 were amplified using primer OPS-16, this specific 1.7 kb fragment was also produced in Elytrigia intermedia, Zhong5 and Z1. When self-bred progenies of resistant and susceptible Z1 individuals were amplified using primer OPS-16, this specific 1.7 kb fragment was amplified in progenies of resistant individuals of Z1, but not in progenies of susceptible individuals.
DE: plant diseases\plant pathogens\plant viruses\barley yellow dwarf luteovirus\strains\wheat\Triticum aestivum\lines\Elymus hispidus\genomes\disease resistance\molecular genetics\random amplified polymorphic DNA
GL: China
AN: 0M07804614\6T01602700\0P06911924
TI: Comparison of nucleotide sequences from three potato leaf roll virus (PLRV) isolates collected in Brazil.
AU: Souza-Dias, J. A. C. de\ Russo, P.\ Miller, L.\ Slack, S. A.
JN: American Journal of Potato Research
YR: 1999
VL: 76
NO: 1
PP: 17-24
LA: En
MS: 26 ref.
AA: Instituto Agronomico de Campinas, Cx.P. 28, 13001-970, Campinas, SP, Brazil.
AB: Polymerase chain reaction linked automated sequencing was used to compare the relatedness of Brazilianpotato leafroll luteovirus (PLRV) isolates obtained from potatoes. By comparing PLRV genomic sequences from Holland, Poland, Canada, Scotland, and Australia (GeneBank), 3 primer pairs were designed and made that would hybridize to all 5 isolates. The primer pairs amplified 3 variable regions which displayed distinctive nucleotide variations in each isolate. These primer pairs were used in the reverse-transcription polymerase chain reaction (RT-PCR) to analyse analogous variable regions in 3 PLRV isolates from around Sao Paulo State, Brazil (2 from field potatoes grown 500 km apart, 1 from Datura stramonium). Each primer pair amplified a DNA product of predicted size from the Brazilian isolates and an isolate from Wisconsin, USA. All of the PCR products were directly sequenced. Comparisons of the variable region sequences from the 3 Brazilian isolates to the 5 isolates from GenBank and the 1 from Wisconsin, revealed that the Brazilian isolates were approx. 99% homologous with each other, 97% with the European and Canadian isolates, and 95% with the USA and Australian isolates. It is suggested that the primer pairs utilised in this study could be used to detect PLRV (by RT-PCR) for diagnostic purposes, and could be used to differentiate between different PLRV isolates for epidemiological purposes.
DE: isolates\nucleotide sequences\potato leaf roll luteovirus\Luteovirus\Datura stramonium\DNA\polymerase chain reaction\potatoes\Solanum\molecular genetics\phylogeny\plant diseases\plant pathogens\plant viruses\genomes\DNA\identification\diagnosis\epidemiology\genome analysis
GL: Brazil\Australia\Poland\Sao Paulo\Scotland\UK\USA\Wisconsin\Canada\Netherlands
AN: 7K02400769\0M07804734
TI: Transgenic wheat plants resistant to barley yellow dwarf virus obtained by pollen tube pathway-mediated transformation.
CT: Chinese agricultural sciences: for the compliments to the 40th anniversary of the founding of the Chinese Academy of Agricultural Sciences [edited by Editorial Department of Scientia Agricultura Sinica].
AU: Cheng ZhuoMin\ He XiaoYuan\ Chen CaiCeng\ Zhang Jie\ Wu MaoSen\ Zhou GuangHe
YR: 1997
PP: 98-108
BN: ISBN 7-80119-467-5
LA: En
LS: ch
MS: 41 ref.
AA: Institute of Plant Protection, CAAS, Beijing 100094, China.
AB: An efficient pollen tube pathway-mediated transformation protocol was developed for a generation of transgenic wheat plants expressing coat protein (CP) of GPV, a Chinese serotype isolate of the barley yellow dwarf luteovirus (BYDV). Molecular analysis of the CP gene in transgenic plants confirmed the stable integration of the CP gene into the wheat genome and inheritance of the gene in T1, T2 and T3 generations. The CP gene segregated as a dominant Mendelian trait in T1 selfed plants. Upon inoculation with GPV in greenhouse tests, transgenic plants that expressed the CP gene exhibited a significant delay of disease development compared with control plants. Field trials showed a high level of resistance to virus infection in T2 and T3 plants, indicating that the resistance trait was stably transmitted to transgenic T1, T2 and T3 plants.
DE: genetic transformation\wheat\Triticum aestivum\transgenic plants\inheritance\coat proteins\barley yellow dwarf luteovirus\plant viruses\plant diseases\disease resistance\books
AN: 7B99999999\6T01502776\0P06807873\0M07708133
TI: Transformation of potato (cv. Late Harvest) with the potato leafroll virus coat protein gene, and molecular analysis of transgenic lines.
AU: Murray, S. L.\ Burger, J. T.\ Oelofse, D.\ Cress, W. A.\ Staden, J. van\ Berger, D. K.
JN: South African Journal of Science
YR: 1998
VL: 94
NO: 6
PP: 263-268
LA: En
MS: 39 ref.
AA: Biotechnology Division, ARC-Roodeplaat Vegetable and Ornamental Plant Institute, Private Bag X293, Pretoria, 0001 South Africa.
AB: Potato leaf roll luteovirus (PLRV) is one of the most destructive potato viruses in South Africa. In order to establish resistance against PLRV in the potato cultivar Late Harvest, the coat protein (CP) gene of a South African isolate of the virus was isolated, cloned into the plant transformation vector pBI121 and inserted into potatoes using Agrobacterium tumefaciens-mediated transformation. Six plantlets, which appeared to be phenotypically normal, were regenerated from leaf discs under kanamycin selection. These lines were analysed for stable transgene insertion and expression. The presence of the PLRV CP, uidA (GUS) and nptII (kanamycin resistance) genes were shown using PCR. Southern blot analysis verified that the PLRV CP gene had been inserted into the genome of the transgenic potato lines. Coat protein was not detected, but RNA dot blots demonstrated PLRV CP gene expression at the mRNA level. Expression of the uidA gene was investigated using a fluorometric assay, and it was observed that lines containing the PLRV CP gene in the antisense orientation exhibited GUS activity.
DE: genetic transformation\coat proteins\potato leaf roll luteovirus\transgenics\gene expression\genes\messenger RNA\potatoes\Solanum tuberosum\plant pathogens\plant viruses\disease resistance\genes\plant diseases
AN: 0M07800473\7K02400299\0P06902246
TI: Barley yellow dwarf virus-PAV RNA does not have a VPg.
AU: Shams-Bakhsh, M.\ Symons, R. H.
JN: Archives of Virology
YR: 1997
VL: 142
NO: 12
PP: 2529-2535
LA: En
MS: 22 ref.
AA: Department of Plant Science, Waite Institute, University of Adelaide,Glen Osmond, SA 5064, Australia.
AB: The genus Luteovirus is divided into 2 subgroups. It has been shown that a genome-linked protein (VPg) is covalently attached to the 5’-end of the genomic RNA of subgroup II luteoviruses. It was investigated whether a VPg is present or absent on the genomic RNA of subgroup I luteoviruses. A simple and sensitive method was developed for the detection of the VPg on virion genomic RNA. This procedure involved hybridizing a 5’-(32)P-labelled oligodeoxynucleotide to the known 5’-terminal sequence of the viral RNA, digesting this complex with RNase T1 (which cleaves on the 3’-side of G residues in regions of single-stranded RNA), and then fractionating the reaction mixture using non-denaturing acrylamide gel electrophoresis. Viral RNAs which do not contain VPg would produce a labelled DNA:RNA hybrid. This would migrate to a similar position as a size marker of the double-stranded DNA form of the oligodeoxynucleotide used in the hybridization step. For viral RNAs with VPg, the labelled product would migrate more slowly because of the presence of VPg. This method was used to show that a VPg is not attached to the 5’-end of the RNA genome of barley yellow dwarf luteovirus-PAV, which is a member of subgroup I luteoviruses.
DE: luteoviruses\plant pathogens\plant viruses\barley yellow dwarf luteovirus\proteins\RNA\molecular genetics\genomic RNA\techniques
AN: 0M07707255
TI: Influence of imidacloprid after seed-treatment of maize on the sucking behavior of the bird-cherry aphid (Rhopalosiphum padi L.) and on the transmission of BYDV using electrical penetration graph technique in laboratory investigations.
FT: Laboruntersuchungen mittels Electrical Penetration Graph zum Einfluss von Imidacloprid als Saatgutbehandlungsmittel am Mais auf das Saugverhalten der Traubenkirschenlaus (Rhopalosiphum padi L.) und die Virusübertragung von BYDV.
AU: Abraham, K.\ Epperlein, K.
JN: Gesunde Pflanzen
YR: 1999
VL: 51
NO: 3
PP: 90-94
LA: De
LS: en
MS: 14 ref.
AA: Universität Halle-Wittenberg, Land-wirtschaftliche Fakultät, Institut für Pflanzenzüchtung und Pflanzenschutz, Postfach 1, D-06108 Halle (Saale), Germany.
AB: EPG (electrical penetration graph)-measurements in the laboratory showed that imidacloprid strongly reduced the sucking activity of Rhopalosiphum padi. Imidacloprid reduced the transmission of BYDV-PAV (barley yellow dwarf luteovirus) in maize cv. Helga by 65%. It was demonstrated that a short inoculation period of 32 s was enough to infect maize plants with the persistent virus.
DE: behaviour\imidacloprid\Zea mays\maize\Rhopalosiphum\Rhopalosiphum padi\transmission\plant viruses\insect pests\insecticides\barley yellow dwarf luteovirus\vectors\effects
AN: 0E08707677\6P01502118
TI: The molecular basis of the interactions between luteoviruses and their aphid vectors.
AU: Hogenhout, S. A.
YR: 1999
PP: 119 pp.
BN: ISBN 90-5808-052-8
LA: En
AA: Wageningen Agricultural University, Wageningen, Netherlands.
AB: In this thesis the molecular relationships of luteoviruses and aphids were investigated. The interaction of the potato leafroll luteovirus (PLRV) and Myzus persicae were used as a model system. Aphid derived proteins were isolated that influenced luteovirus transmission. A 60 kDa protein (p63) that specifically bound to luteoviruses was identified and characterized. The groE operon of an endosymbiont of Myzus (Buchnera sp.) was characterized and the PLRV-binding domain of Buchnera GroEL was identified and site directed mutagenesis was carried out. Experiments were also carried out to determine whether the minor or major luteovirus capsid proteins were involved in binding to Buchnera GroEL. Attempts were made to define the exact binding position of GroEL. The effects of neem seed kernel extracts on the primary endosymbiotic bacteria of M. persicae were studied.
DE: plant diseases\plant pathogens\plant viruses\transmission\plant pests\insect pests\vectors\proteins\genes\binding\characterization\Myzus persicae\potato leafroll luteovirus\Luteovirus\amino acid sequences\molecular genetics\Azadirachta indica\plant extracts\kernels
AN: 0M07806808\0E08711340\7K02401666
TI: Modelling the incidence of virus yellows in sugar beet in the UK in relation to numbers of migrating Myzus persicae.
AU: Werker, A. R.\ Dewar, A. M.\ Harrington, R.
JN: Journal of Applied Ecology
YR: 1998
VL: 35
NO: 5
PP: 811-818
LA: En
MS: 38 ref.
AA: IACR-Broom's Barn, Higham, Bury St Edmunds, Suffolk IP28 6NP, UK.
AB: The incidence of virus yellows diseases (caused by beet yellowing virus [beet yellows closterovirus] and/or beet mild yellowing luteovirus) in sugar beet crops in eastern England during 1965-96 was analysed in relation to numbers of migrating M. persicae. A non-linear model was fitted to the data incorporating dual routes of infection: primary infection, arising from winged immigrant aphids carrying the virus, and secondary infection, arising from local dispersion of their wingless offspring transferring the virus from infected to uninfected plants. A good description of virus yellows incidence in August depended on allowing the rate parameters for primary and secondary infection to decrease sigmoidally over the years during 1965-96. The shape of this function depicted a major change in the epidemiology of virus yellows since 1974-76. Amongst several contributory factors, this change coincided with the introduction and subsequent wide use of systemic granular pesticides. Good fits also depended on allowing the rates of disease progress to decay with time to accommodate effects of increasing host resistance with plant age to feeding aphids. Given that the changes in the epidemiology of virus yellows over the years are associated with improvements in pest management practices, it is suggested that the model presents a useful extension to disease forecasting by providing predictions of disease risk in the absence of pesticides.
DE: Myzus persicae\sugarbeet\Aphidoidea\dispersion\epidemiology\feeding\forecasting\pest management\pesticides\vectors\Beta vulgaris var. saccharifera\plant diseases\plant pathogens\plant viruses\plant pests\insect pests\insecticides\mathematical models\models\beet yellows closterovirus\beet mild yellowing luteovirus\Luteovirus\Closterovirus\disease resistance\transmission
GL: UK\England
AN: 0M07804926\0E08708823
TI: Variation among clones of Myzus persicae and Myzus nicotianae in the transmission of a poorly and a highly aphid-transmissible isolate of potato leafroll luteovirus (PLRV).
CT: Proceedings of the 7th international congress of plant pathology, Edinburgh, UK, 9-16 August 1998 [edited by Johnson, R.].
AU: Bourdin, D.\ Rouzé, J.\ Tanguy, S.\ Robert, Y.
JN: Plant Pathology
YR: 1998
VL: 47
NO: 6
PP: 794-800
LA: En
MS: 31 ref.
AA: INRA, Station de Pathologie Végétale, BP 29, 35653 Le Rheu Cedex, France.
AB: Fifteen clones of Myzus persicae (Mp) and 2 of Myzus nicotianae (Mn) were used to assess the aphid transmission of 2 isolates of PLRV characterized as highly (HAT) and poorly (PAT) transmissible. Experiments conducted under controlled conditions showed that the HAT isolate was very efficiently transmitted by all the clones tested. In contrast, an important aphid clonal effect was observed with the PAT isolate, with mean transmission rates by 15 clones being low (0-26%) and by the 2 others much higher (57 and 71%). Transmission values for each clone were shown to be stable over time and independent of the kind of source plant used for acquisition, either infected Physalis floridana plants propagated by cuttings or grown from seedlings previously inoculated by aphids. It is concluded that poor transmissibility cannot be related to intrinsic properties of either the viral particles or the aphid clones on their own: the transmission process and its specificity depend on interactions between both parameters.
DE: potato leaf roll luteovirus\plant diseases\plant pathogens\plant viruses\Physalis floridana\Myzus persicae\Myzus nicotianae\disease transmission\insect vectors\Luteovirus\clones\transmission
AN: 0E08704260\0M07803245
TI: First report of pea enation mosaic virus affecting lentil (Lens culinaris) in Syria.
AU: Makkouk, K. M.\ Kumari, S. G.\ Bassam Bayaa
JN: Plant Disease
YR: 1999
VL: 83
NO: 3
PP: 303
LA: En
MS: 2 ref.
AA: Virology Laboratory, Germplasm Program, International Center for Agricultural Research in the Dry Areas (ICARDA), P.O. Box 5466, Aleppo, Syria.
AB: Symptoms suggestive of virus infection in lentil fields in Dara'a in southern Syria have been observed, in epidemic proportions, almost equally since 1994. A similar epidemic was observed on many lentil genotypes at the ICARDA farm, near Aleppo, as well as other locations in northern Syria during 1998. Symptoms included growth reduction and rolling of leaves, accompanied by mottling with tip wilting or necrosis. Field symptoms were reproduced on lentil cv. Syrian Local upon mechanical inoculation of plants with inoculum from symptomatic field plants. Transmission tests showed that the disease agent can be transmitted from lentil to lentil, pea and faba bean (Vicia faba) plants by the pea aphid (Acyrthosiphon pisum) in a persistent manner. More than 500 symptomatic lentil plants were collected and tested for the presence of 14 different viruses by the tissue-blot immunoassay. Around 80% of the samples reacted only with antiserum to pea enation mosaic enamovirus (PEMV). Surveys conducted during the 1997-98 growing season showed that PEMV was widely distributed in the major lentil-growing areas of Syria: some lentil fields had more than 50% virus incidence.
DE: plant diseases\plant pathogens\plant viruses\pea enation mosaic enamovirus\Lens culinaris\lentils\symptoms\epidemics\disease surveys\transmission\Acyrthosiphon pisum\immunodiagnosis\incidence
GL: Syria
AN: 0M07804724\0E08708680
TI: Beet western yellows luteovirus in Western Oregon: pathosystem relationships in a vegetable-sugar beet seed production region.
AU: Hampton, R. O.\ Keller, K. E.\ Baggett, J. R.
JN: Plant Disease
YR: 1998
VL: 82
NO: 2
PP: 140-148
LA: En
MS: 40 ref.
AA: U.S. Department of Agriculture, Agricultural Research Service, Oregon State University, Corvallis, USA.
AB: The history of beet western yellows luteovirus (BWYV), the biology and epidemiology of this plant virus, the assays used for incidence assessment of BWYV, the presence of BWYV in vegetable and sugarbeet seed crops and associated weeds are all discussed with reference to cause risks to BWYV-susceptible crops in western Oregon, USA.
DE: plant diseases\plant pathogens\plant viruses\beet western yellows luteovirus\sugarbeet\vegetables\seed production\interactions\biology\symptoms\epidemiology\Aphidoidea\disease transmission\disease vectors\weeds\immunoassay\ELISA\crop production\reviews\weeds
GL: USA\Oregon
AN: 0M07704236\0W04701748
TI: Barley yellow dwarf viruses.
AU: Miller, W. A.\ Rasochová, L.
JN: Annual Review of Phytopathology
YR: 1997
VL: 35
PP: 167-190
LA: En
MS: 119 ref.
AA: Plant Pathology Department, Iowa State University, Ames, IA 50010-1020, USA.
AB: This review focuses on 4 research areas with respect to barley yellow dwarf luteoviruses (BYDVs): evidence supporting reclassification of BYDVs into 2 genera; elucidation of gene function and novel mechanisms controlling gene expression; initial attempts to understand the complex interactions between BYDV virions and their aphid vectors; and replication of a BYDV satellite RNA. Economic losses, symptomatology and means of control of BYDVare also discussed.
DE: plant diseases\plant pathogens\plant viruses\barley yellow dwarf luteovirus\barley\reviews\molecular genetics\gene expression
AN: 0M07701922\6T01501461
TI: Evidence for the North American origin of Rhopalosiphum and barley yellow dwarf virus.
CT: Aphids in natural and managed ecosystems. Proceedings of the Fifth International Symposium on Aphids, Leon, Spain, 15-19 September, 1997 [edited by Nieto Nafrìa, J. M.; Dixon, A. F. G.].
AU: Halbert, S. E.\ Voegtlin, D. J.
YR: 1998
PP: 351-356
BN: ISBN 84-7719-628-1
LA: En
MS: 15 ref.
AA: Division of Plant Industry, Florida Department of Agriculture and Consumer Services, PO Box 147100, Gainesville, FL 32614-7100, USA.
AB: This paper presents evidence that North America is the center of origin for the genus Rhopalosiphum and for the complex of plant viruses collectively known as barley yellow dwarf virus (BYDV). These hypotheses are based on world wide distribution and biology of the organisms. The center of diversity for the genus Rhopalosiphum is North America. Most, if not all, of the species in the genus occur in North America. The majority of those that occur outside of North America are cosmopolitan pests. Holocycles for at least three of the five cosmopolitan pests have been documented in North America. BYDV has a wide host range among Poaceae, making it unlikely that evolution of the virus complex is driven by plant host. It is more likely that the virus complex evolves with vector specificity. BYDV's are regularly classified both by vector specificity and by serology. There is a correlation between serotype and vector specificity, possibly because both phenomena are mediated by the configuration of the viral coat protein. Although this onship between transmission and serotype has been fairly stable, some North American variants of all described serotypes are transmissible by Rhopalosiphum padi. This suggests that R. padi, which is probably a North American species, may be the original natural vector of the complex. Finally, western North America is the apparent center of diversity for BYDV variants. All five serotypes can be found, and most occur with a wide variety of transmission specificities. It is suggested that BYDV originated in western North America, with R. padi as its natural vector. With the introduction of new aphid pests, the virus complex evolved as vector opportunities became available.
DE: North America\Rhopalosiphum\viruses\barley yellow dwarf luteovirus\America\host range\plant viruses\Poaceae\Rhopalosiphum padi\serology\serotypes\transmission\vectors\conferences
AN: 0E08708506