Infection of Axenic Eucalyptus Seedlings With Phytophthora cinnamomi Zoospores

Abstract

Young Eucalyptus seedlings were raised axenically and infected with small numbers of Phytophthora cinnamomi zoospores at the root tip. The linear extent of hyphal growth up the root was measured from 2 to 4 days and shown to be significantly greater in the highly susceptible species of Eucalyptus when compared with those which are less susceptible in the field. Sporangium production on the root was observed on both highly susceptible and less susceptible species in the presence of free water and certain salts.