The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform

Roger Hull - One of the best experts on this subject based on the ideXlab platform.

  • Some biological and genomic properties of rice tungro bacilliform badnavirus and rice tungro spherical Waikavirus from Nepal
    Annals of Applied Biology, 1996
    Co-Authors: G. Dahal, A. Druka, T M Burns, L C Villegas, Z. Fan, Ram B. Shrestha, Roger Hull
    Abstract:

    Summary. A survey of rice fields during the main growing seasons in 81 locations from 21 districts of the Southern Terai region of Nepal indicated that rice tungro was primarily restricted to the Hardinath (Janakpur) and Parwanipur (Bara) regions. The tungro incidence in Hardinath ranged from 17% to 51% and in Parwanipur from 6% to 61% causing about 89% grain yield loss in Hardinath. Both rice tungro bacilliform badnavirus (RTBV) and rice tungro spherical picornavirus (RTSV) were found in tungro isolates collected from Hardinath and Parwanipur. These isolates were transmitted by Nephotettix virescens and leaf extracts reacted to antisera against RTBV and RTSV. In a dot blot hybridisation assay, leaf extracts of 12 weed species collected from the tungro-affected area in Hardinath and Parwanipur also reacted with RTBV DNA probes. On mass inoculation of 15 popular rice cultivars most became more than 50% infected and only cv. Radha 9 had low (22.2%) infection. RTBV DNA and the coat protein region of RTSV from the Hardinath isolate were cloned and partially characterised. A comparative analyses by restriction endonuclease digestion, cross hybridisation, the polymerase chain reaction and partial sequencing indicated that the Nepalese RTBV DNA clone and the cDNA clones of the RTSV RNA were more similar to the various tungro isolates from the Indian subcontinent than to those from the Philippines.

Thierry Wetzel - One of the best experts on this subject based on the ideXlab platform.

  • Secoviridae: a proposed family of plant viruses within the order Picornavirales that combines the families Sequiviridae and Comoviridae, the unassigned genera Cheravirus and Sadwavirus, and the proposed genus Torradovirus
    Archives of Virology, 2009
    Co-Authors: Joan Wellink, Olivier Gall, Alexander Karasev, René Vlugt, Thierry Wetzel
    Abstract:

    The order Picornavirales includes several plant viruses that are currently classified into the families Comoviridae (genera Comovirus , Fabavirus and Nepovirus ) and Sequiviridae (genera Sequivirus and Waikavirus ) and into the unassigned genera Cheravirus and Sadwavirus . These viruses share properties in common with other picornavirales (particle structure, positive-strand RNA genome with a polyprotein expression strategy, a common replication block including type III helicase, a 3C-like cysteine proteinase and type I RNA-dependent RNA polymerase). However, they also share unique properties that distinguish them from other picornavirales. They infect plants and use specialized proteins or protein domains to move through their host. In phylogenetic analysis based on their replication proteins, these viruses form a separate distinct lineage within the picornavirales branch. To recognize these common properties at the taxonomic level, we propose to create a new family termed “Secoviridae” to include the genera Comovirus , Fabavirus , Nepovirus , Cheravirus , Sadwavirus , Sequivirus and Waikavirus . Two newly discovered plant viruses share common properties with members of the proposed family Secoviridae but have distinct specific genomic organizations. In phylogenetic reconstructions, they form a separate sub-branch within the Secoviridae lineage. We propose to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae.

G. Dahal - One of the best experts on this subject based on the ideXlab platform.

  • Some biological and genomic properties of rice tungro bacilliform badnavirus and rice tungro spherical Waikavirus from Nepal
    Annals of Applied Biology, 1996
    Co-Authors: G. Dahal, A. Druka, T M Burns, L C Villegas, Z. Fan, Ram B. Shrestha, Roger Hull
    Abstract:

    Summary. A survey of rice fields during the main growing seasons in 81 locations from 21 districts of the Southern Terai region of Nepal indicated that rice tungro was primarily restricted to the Hardinath (Janakpur) and Parwanipur (Bara) regions. The tungro incidence in Hardinath ranged from 17% to 51% and in Parwanipur from 6% to 61% causing about 89% grain yield loss in Hardinath. Both rice tungro bacilliform badnavirus (RTBV) and rice tungro spherical picornavirus (RTSV) were found in tungro isolates collected from Hardinath and Parwanipur. These isolates were transmitted by Nephotettix virescens and leaf extracts reacted to antisera against RTBV and RTSV. In a dot blot hybridisation assay, leaf extracts of 12 weed species collected from the tungro-affected area in Hardinath and Parwanipur also reacted with RTBV DNA probes. On mass inoculation of 15 popular rice cultivars most became more than 50% infected and only cv. Radha 9 had low (22.2%) infection. RTBV DNA and the coat protein region of RTSV from the Hardinath isolate were cloned and partially characterised. A comparative analyses by restriction endonuclease digestion, cross hybridisation, the polymerase chain reaction and partial sequencing indicated that the Nepalese RTBV DNA clone and the cDNA clones of the RTSV RNA were more similar to the various tungro isolates from the Indian subcontinent than to those from the Philippines.

Joan Wellink - One of the best experts on this subject based on the ideXlab platform.

  • Secoviridae: a proposed family of plant viruses within the order Picornavirales that combines the families Sequiviridae and Comoviridae, the unassigned genera Cheravirus and Sadwavirus, and the proposed genus Torradovirus
    Archives of Virology, 2009
    Co-Authors: Joan Wellink, Olivier Gall, Alexander Karasev, René Vlugt, Thierry Wetzel
    Abstract:

    The order Picornavirales includes several plant viruses that are currently classified into the families Comoviridae (genera Comovirus , Fabavirus and Nepovirus ) and Sequiviridae (genera Sequivirus and Waikavirus ) and into the unassigned genera Cheravirus and Sadwavirus . These viruses share properties in common with other picornavirales (particle structure, positive-strand RNA genome with a polyprotein expression strategy, a common replication block including type III helicase, a 3C-like cysteine proteinase and type I RNA-dependent RNA polymerase). However, they also share unique properties that distinguish them from other picornavirales. They infect plants and use specialized proteins or protein domains to move through their host. In phylogenetic analysis based on their replication proteins, these viruses form a separate distinct lineage within the picornavirales branch. To recognize these common properties at the taxonomic level, we propose to create a new family termed “Secoviridae” to include the genera Comovirus , Fabavirus , Nepovirus , Cheravirus , Sadwavirus , Sequivirus and Waikavirus . Two newly discovered plant viruses share common properties with members of the proposed family Secoviridae but have distinct specific genomic organizations. In phylogenetic reconstructions, they form a separate sub-branch within the Secoviridae lineage. We propose to create a new genus termed Torradovirus (type species, Tomato torrado virus) and to assign this genus to the proposed family Secoviridae.

Hong-soo Choi - One of the best experts on this subject based on the ideXlab platform.

  • Complete genome sequence of bellflower vein chlorosis virus, a novel putative member of the genus Waikavirus
    Archives of Virology, 2015
    Co-Authors: Hae-ryun Kwak, Hong-soo Choi
    Abstract:

    The complete genome sequence of a new virus isolated from a bellflower ( Campanula takesimana ) plant was determined. The genome of this virus is composed of monopartite single-stranded RNA of 11,649 nucleotides in length. BLAST searches of protein databases showed that the encoded polyprotein has a maximum amino acid sequence identity of 42 % (with 99 % coverage) to the polyprotein of the isolate Orissa of rice tungro spherical virus (RTSV; genus Waikavirus ). Phylogenetic analysis strongly supports that the identified virus is a member of a new species of the genus Waikavirus . The name bellflower vein chlorosis virus (BVCV) is proposed for this new virus.