Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2004
Publication Date: August 20, 2004
Citation: Martin, F.N., Tooley, P.W. The use of mitochondrial dna for clarifying phylogenetic relationships and isolate identification with the genus phytophthora. Phytopathology. 2004. v. 94 p. S66. Technical Abstract: This abstract describes molecular methods based on mitochondrial DNA that have been developed for the genus Phytophthora that can be used for understanding the evolutionary relationships among species, detecting the presence of this genus in infected plant tissue, and for identification of individual species based on RFLP analysis. The mitochondrial genome in Phytophthora has provided additional tools for phylogenetic analysis (cox 1 and 2 genes) of the genus that allows for greater resolution among closely related species that the more commonly used rDNA-ITS region. In addition, a molecular marker system for detection of the pathogen in infected tissue was developed from mtDNA that uses a primer pair that is specific for Phytophthora spp. multiplexed with a plant primer pair that serves as a positive control. A second round amplification with nested species-specific primers was used to detect specific species. This marker system was most widely tested with P. ramorum, but has been found to work on a range of other species as well. An alternative approach for isolate identification was developed using RFLP analysis of another PCR amplified region to accurately identify isolates to a species level. In evaluation with 153 isolates representing 31 species isolates were consistently identified to the correct species, including those not clearly differentiated by RFLP analysis of the rDNA-ITS region.