Analysis of variability in partial sequences of genomes of Tobacco yellow dwarf virus isolates

Australasian Plant Pathology (Impact Factor: 1.02). 01/2004; 33(3):367-370. DOI: 10.1071/AP04023

ABSTRACT The movement protein coding region of six isolates of Tobacco yellow dwarf virus (TYDV), collected over a 30 year period from various regions throughout Australia, was analysed using PCR and DNA sequencing.
Four isolates of Bean summer death virus, considered a synonym of TYDV, were also analysed. Phylogenetic analysis showed that
all 10 isolates were greater than 95% homologous to the published TYDV sequence (GenBank accession number M81103). The weed
Raphanus raphanistrum was identified as an alternative host of TYDV for the first time.

Additional keywordsBean summer death virus–detection, geminivirus–mastrevirus–TYDV

  • [Show abstract] [Hide abstract]
    ABSTRACT: The complete genome for a barley isolate of Wheat dwarf virus (WDV) from Tekirdağ, Turkey, WDV-Bar[TR], was isolated and sequenced. The genome was found to be 2739 nucleotides long, which is shorter than wheat-infecting WDV isolates, and with a genome organization typical for mastreviruses. The complete genome of WDV-Bar[TR] showed 83-84% nucleotide identity to wheat isolates of WDV, with the non-coding regions SIR and LIR least conserved (72-74% identity). The deduced amino acid sequences for Rep and RepA were most conserved (92-93%), while CP and MP were less conserved (87% and 79-80%, respectively). The identity to other mastrevirus species was significantly lower. In phylogenetic analyses, the WDV isolates formed a distinct clade, well separated from the other mastreviruses with the wheat isolates grouping closely together. Phylogenetic analyses of WDV-Bar[TR], the partial sequence for another Turkish barley isolate (WDV-Bar[TR2]) and published WDV sequences further supported the division of WDV into two distinct strains. The barley strain could also be divided into three subtypes based on relationships and geographic origin. This study shows the first complete published sequence for a barley isolate of WDV.
    Virus Genes 07/2007; 34(3):359-66. · 1.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Factors that determine the epidemiology of Tobacco yellow dwarf virus (TbYDV), including alternative host plants and insect vector(s), were assessed over three consecutive growing seasons at four field sites in Northeastern Victoria in commercial tobacco growing properties. In addition, these factors were assessed for one growing season at three bean growing properties. Overall, 23 leafhopper species were identified at the 7 sites, with Orosius orientalis as the predominant leafhopper. Of the leafhoppers collected, only O. orientalis and Anzygina zealandica tested positive for TbYDV by polymerase chain reaction (PCR). The population dynamics of O. orientalis was assessed using sweep net sampling over three growing seasons and a trimodal distribution was observed. Despite large numbers of O. orientalis occurring early in the growing season (September–October), TbYDV was only detected in these leafhoppers between late November and end of January. The peaks in the detection of TbYDV in O. orientalis correlated with the observation of disease symptoms in tobacco and bean and were associated with warmer temperatures and lower rainfall. Spatial and temporal distribution of vegetation at selected sites was determined using quadrat sampling. Of the 40 plant species identified, TbYDV was detected only in four dicotyledonous species, Amaranthus retroflexus, Phaseolus vulgaris, Nicotiana tabacum and Raphanus raphanistrum. The proportion of host and non-host availability for leafhoppers was associated with climatic conditions.
    Annals of Applied Biology 06/2010; 157(1):13 - 24. · 2.15 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Natural infection by mastreviruses was investigated in chickpea (Cicer arietinum) and other dicotyledonous crops and weeds in grain production areas of Queensland and northern New South Wales, Australia, from 2000 to 2005. Altogether, 33 639 plants comprising 31 species and 10 dicot families were screened for infection by a tissue-blot immunoassay that did not distinguish between mastrevirus strains or species. Nine plant species in three families were identified as natural hosts. Chickpea was infected throughout the region although infection incidence did not exceed 5%. Infection was rare in faba bean (Vicia faba), canola (Brassica napus), and mustard (B. juncea) and not detected in field pea (Pisum sativum). Infection of chickpea and turnip weed (Rapistrum rugosum) was confirmed by immunocapture polymerase chain reaction (IC-PCR) with primers generic for dicot-infecting mastreviruses, and also immunosorbent electron microscopy and graft transmission in the case of chickpea. Individual mastreviruses were identified by comparing their IC-PCR amplicons by a combination of methods. Among 42 isolates from 41 chickpea plants, one was typical Tobacco yellow dwarf virus (TYDV) and the others were three recently distinguished strains including two proposed novel species: 34 Chickpea chlorosis virus strain A, six Chickpea chlorosis virus strain B, and one Chickpea redleaf virus. All of 10 isolates from 10 turnip weed plants were TYDV-B, a strain distinct from typical TYDV. The symptoms associated with mastrevirus infection in chickpea included foliar chlorosis or reddening, stunting, and usually phloem browning. The potential for losses in winter and summer grown field crops is discussed.
    Australasian Plant Pathology 39(6):551-561. · 1.02 Impact Factor