Genetic variation and host specificity of Phytophthora cactorum

摘要

The morphological differences found in Phytophtora cactorum isolates from different host species were insufficient for the identification of genetic groups or host origin. The oogonia of P. cactorum isolates from different hosts were different from each other, but the variation among isolates from the same host was also in most cases significant. The random amplified microsatellite (RAMS) technique revealed considerable variation among P. cactorum isolates. In UPGMA-dendrogram all isolates from birch were within one of the four major branches. P. cactorum population on strawberry was much more variable in North America than in Europe. The pathogenicity tests done in greenhouse with silver birch, common alder and strawberry seedlings suggested thatisolates of P. cactorum would be more virulent to their original hosts than to other plants.