New microsatellite markers for population studies of Phytophthora cinnamomi, an important global pathogen

AbstractPhytophthora cinnamomiis 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. cinnamomiaffects 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 studyingP. cinnamomi. Using available genome sequences for three isolates ofP. 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 onP. cinnamomipopulations 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 ofP. cinnamomiand will aid in the understanding of the origin and invasion history of this important species.