Abstract:
Phytophthora cinnamomi is the causal agent of root rot, canker and dieback of thousands of plant
species around the globe. This oomycete not only causes severe economic losses but also threatens
natural ecosystems. In South Africa, P. cinnamomi affects eucalyptus, avocado, macadamia and
indigenous fynbos. Despite being one of the most important plant pathogens with a global distribution,
little information is available regarding origin, invasion history and population biology. This is partly
due to the limited number of molecular markers available for studying P. cinnamomi. Using available
genome sequences for three isolates of P. cinnamomi, sixteen polymorphic microsatellite markers
were developed as a set of multiplexable markers for both PCR and Gene Scan assays. The application
of these markers on P. cinnamomi populations from avocado production areas in South Africa revealed
that they were all polymorphic in these populations. The markers developed in this study represent a
valuable resource for studying the population biology and movement of P. cinnamomi and will aid in the
understanding of the origin and invasion history of this important species.
