GREMMENIELLA-ABIETINA AND G-LARICINA IN EUROPE - CHARACTERIZATION AND IDENTIFICATION OF ISOLATES AND LABORATORY STRAINS BY SOLUBLE-PROTEIN ELECTROPHORESIS

Forty-four isolates of Gremmeniella abietina from different European regions and laboratory strains of G. abietina and Ascocalyx abietis, which originated from regenerated protoplasts, were characterized morphologically and by protein electrophoresis. On the basis of the electrophoretic profiles of all isolates tested, the North American race of G. abietina is not present in Europe. Isolates from Pinus cembra and two Finnish isolates differed slightly from the tester strain for the European race; their electromorphs were very similar to that of the European race on other hosts but differences were noticed that would support the maintenance of the variety cembrae. Gremmeniella abietina var. balsamea, common on Abies balsamea and Picea spp. in Quebec, Canada, seems to be absent from the European counterparts Abies alba and Picea abies. The isolates from P. abies belong unequivocally to the European race of G. abietina. European isolates of G. laricina were morphologically and electrophoretically indistinguishable from the North American ones. The P. cembra and Larix decidua endophytes showed the same electrophoretic profile as the isolates from diseased pines identified as Brunchorstia pinea var. cembrae. No changes in the electrophoretic patterns of laboratory strains derived from regenerated protoplasts, compared with those of the original isolates, were observed. Two isolates from Abies do not belong to any known species of Brunchorstia; on the basis of morphological, electrophoretic, and immunological evidence they belong to a taxon taxonomically close to G. abietina.