Évolution comparée de l'amidon et des glucides éthanolo-solubles dans les tumeurs produites par Eriosoma lanigerum sur Pirus malus cultivar 'Calville blanc' et dans les rameaux sains témoins

Abstract

In the tumors caused by Eriosoma lanigerum Haussm. on Pirus malus L. cultivar 'Calville blanc,' the starch disappears gradually and according to a determined order, first in the pathological tissues, then in the underlying healthy ones. This depletion depends on the action of an amylase which is contained in the insect's saliva. Tumoral cells of the xylem never contain starch. The infected shoots are more turgescent than the healthy ones. The amount of mannose is higher in the tumors than in the healthy shoots. It appreciably increases with the growth of tumoral tissues. This increase may be linked to the phenomenon of delignification of the ligneous tissues, in particular the xylem. The tumors also contain some glucose, some raffinose, lactose, maltose, and more saccharose than the healthy shoots.