Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: September 9, 2003
Publication Date: September 13, 2003
Citation: Bowers, J.H., Bailey, B.A., Martin, F.N. 2003. Genetic diversity of temperate and tropical isolates of phytophthora capsici [abstract]. American Phytopathological Society Annual Meeting. Technical Abstract: Phytophthora capsici is a major pathogen of economical crops in both temperate and tropical climates worldwide. Those isolates that are pathogenic on tropical crops have been described as P. tropicalis through morphometric analysis. The research objective was to determine if isolates of P. capsici causing black pod on cacao in Brazil are genetically similar to isolates causing Phytophthora blight on peppers in the U.S. AFLP analysis was used to evaluate genetic diversity. Cluster analysis of AFLP results identified two distinct clusters, consisting of either all temperate isolates or all tropical isolates. Additionally, PCR analysis with PCAP and ITS1 primers and subsequent restriction of the amplicon with Msp1 also was able to differentiate temperate and tropical isolates. Sequence analysis of the PCR product revealed a 166-bp segment with a single base change at the restriction site. Results support the hypothesis of separate populations within the P. capsici / P. tropicalis group. Additional data on mitochondrial gene phylogenies will be presented.