PROTEINIC VARIABILITY OBSERVED BY MEANS O F 2-DIMENSIONAL GEL-ELECTROPHORESIS ON 9 ISOLATES OF HETERODERA-SCHACHTII ORIGINATING FROM 6 EUROPEAN COUNTRIES AND ON 2 ISOLATES OF HETERODERA-TRIFOLII F-SP BETA

Two dimensional gel electrophoresis (2-DGE) was applied on females rea red on standard conditions on rape, Brassica napus L. var. napus cv. S amoural. Gels were compared by a computerized image analysis system. T he similarity index (F) and the genetic distances (D=1-F) were calcula ted on the basis of all spots observed from each isolate being compare d and of the shared spots observed between these isolates. The dendrog ram was obtained according to the UPGMA method. The two species able t o multiply on Beta vulgaris were closely related, and the main differe nces are indicated out by arrows and letters on the figures. Some typi cal spots of isolates of H schachtii were identified. The possible use of 2-DGE for the identification of specific proteins linked to the vi rulence of isolates seems a promising way of investigation. A large sa mpling of isolates is needed.