Molecular and biological characterization of Lettuce mosaic virus (LMV) isolates reveals a distinct and widespread type of resistance-breaking isolate : LMV-most

Renate Krause-Sakate (1, 2) , Olivier O. Le Gall (1) , Hatem Fakhfakh (3) , Martine Peypelut (1) , M. Marrakchi (3) , C. Varveri (4) , M.A. Pavan (5) , Sylvie Souche (6) , Hervé Lot (6) , F.M. Zerbini (2) , Thierry T. Candresse (1)

1 GD2P - Génomique, développement et pouvoir pathogène
2 BIOAGRO - Departamento de Fitopatologia [Viçosa, Brazil]
3 Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie
4 BPI - Benaki Phytopathological Institute
5 UNESP - Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University
6 PV - Unité de Pathologie Végétale

Lettuce mosaic virus (LMV) causes an economically important seedborne and aphid-transmitted disease of lettuce and ornamental crops worldwide. The genetic diversity among 73 LMV isolates was examined based on a 216-nucleotide sequence at the variable region encoding the NIb-coat protein junction, Three clusters of LMV isolates were distinguished: LMV-Yar, LMV-Greck, and LMV-RoW. In the latter cluster, two subgroups of isolates, LMV-Common and LMV-Most, accounted for a large proportion of the LMV isolates analyzed. These two subgroups included the seedborne isolates, consistent with this property contributing a selective advantage and resulting in widespread distribution. In addition to being seedborne, LMV-Most isolates overcome the two resistance genes commonly used in lettuce, mol(1) and mol(2), and thus represent a potential threat to lettuce cultivation. The complete sequence of an LMV-Most isolate (LMV-AF199) was determined, allowing a better definition of the genetic relationships among LMV-Most, LMV-Common, and an additional isolate of the LMV-RoW cluster.

Domaines: Phytopathologie et phytopharmacie; Virologie; Sciences agricoles

Renate Krause-Sakate, Olivier O. Le Gall, Hatem Fakhfakh, Martine Peypelut, M. Marrakchi, et al.. Molecular and biological characterization of Lettuce mosaic virus (LMV) isolates reveals a distinct and widespread type of resistance-breaking isolate : LMV-most. Phytopathology, 2002, 92 (5), pp.563-572. ⟨10.1094/PHYTO.2002.92.5.563⟩. ⟨hal-02678572⟩