Identification of PVY strains in Belgium and determination of the aphid species associations.

Genin, V. Desoignies, N. Francis, F. Bragard, Claude [UCL]

Today, PVY control is mainly based on the use of certified potato seeds and on aphid flights monitoring (Euraphid system and aspiration traps) allowing to inform major flights. On such a basis, control measures are taken within the crop. Our project aims, through a better understanding of the interactions between the PVY and the vector aphids, to propose an alternative approach of the viral control. It can be divided into two parts: - The identification and characterization of the PVY strains present in Wallonia and the determination of associations with the aphid species, with a particular attention for sequences potentially involved in the transmission by the vector. - The study of the interaction between the aphids stylet (Myzus persicae and Aphis gossypii), a viral protein (HC-Pro) and the coat protein which determine the transmissibility and its efficiency in the Potyvirus. In particular, we hypothesize that the interactions of the viral particles with the aphid stylet follow the model of the "bridge" protein and can be inhibited by blocking agents. Data on the type of PVY strains present in Southern Belgium, their distributions and the related aphid species will be presented.