Pathogenicity of Phytophthora cinnamomi Towards Nothofagus cunninghamii

Abstract

Two-year-old plants of Nothofagus cunninghamii were inoculated with isolates of either A1 or A2 mating types of Phytophthora cinnamomi. Both mating types were pathogenic, causing root rot and cankers, and resulting in significant reductions of height and dry weight compared with controls. Death occurred in all host plants inoculated with the A1 mating type, but in only 60% of those inocu- lated with the A2 isolate. Symptoms were correspondingly more severe in plants inoculated with the A1 mating type of the pathogen than in those inoculated with the A2 type.