Plant pathologists track where Phytophthora ramorum came from and how it has managed to spread. The author specifically discusses Phytophthora ramorum clones and mating types and tracking the migration of the pathogen.
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Dr. Niklaus Grünwald
Research Plant Pathologist
Horticultural Crops Research Laboratory
USDA Agricultural Research Service
Associate Professor
Department of Botany and Plant Pathology
Oregon State University
Corvallis, OR.