Technique for Rapid Assessment of Tolerance of Banksia spp. to Root Rot Caused by Phytophthora cinnamomi. Kingsley W. Dixon, Botanist, Kings Park and Botanic Gardens, West Perth 6005, Western Australia. Thinlay, Honors Student, and K. Sivasithamparam, Lecturer, School of Agriculture, Soil Science and Plant Nutrition Group, University of Western Australia, Nedlands 6009, Western Australia. Plant Dis. 68:1077-1080. Accepted for publication 19 May 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-1077.

The technique of stem wound inoculation is described that provides a rapid, reliable method of assessing and calibrating tolerance of Banksia spp. to root rots caused by Phytophthora cinnamomi. Inoculated intact stems and excised stem-cuttings developed characteristic lesion lengths. Similar results for the relative susceptibility of a species were obtained using wound-inoculating and zoospore root-drenching procedures. Both techniques showed Banksia ashbyi, B. verticillata, B. victoriae, and B. prionotes susceptible and B. baueri tolerant to P. cinnamomi. Root lesions were difficult to measure because of secondary infection and irregularities in root morphology. Using intact, field-grown plants, stem lesion length was useful for assessing interspecific and intraspecific tolerance of Banksia spp.

Keyword(s): Proteaceae.