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Genetic diversity of Phytophthora cinnamomi in disease fronts of natural vegetation

Dobrowolski, M.P., Tommerup, I.C., Shearer, B.L. and O'Brien, P.A. (1998) Genetic diversity of Phytophthora cinnamomi in disease fronts of natural vegetation. In: Biodiversity, Biotechnology & Biobusiness - 2nd Asia-Pacific Conference on Biotechnology, 23 - 27 November, Perth, Western Australia.

Abstract

Phytophthora cinnamomi, a global plant pathogen, causes devastating damage to many natural ecosystems in southern Australia due to the low resistance of the dominant vegetation to this introduced pathogen. It is a serious threat to ecosystem biodiversity particularly in southwest Australia. The number of introductions of P. cinnamomi to southern Australia is unknown, although three isozyme types and both A I and A2 mating types have been found. We aimed to survey the genetic structure of P. cinnamomi and assess the potential for sexual reproduction in disease fronts of southwestern Australia. We hierarchically sampled three P. cinnamomi disease fronts, widely spaced in southwestern Australia, which were 600-900 m long with natural vegetation dominated by Banksia spp. P. cinnamomi was isolated from bark of recently dead susceptible plants and adjacent soil samples. The mating types of isolates were determined and genetic analysis performed using five microsatellite loci. The isolates of P. cinnamomi we recovered grouped into three clonal types as indicated by their multilocus microsatellite genotypes, two of A2 and one of Al mating type. One A2 clonal type was common to all three disease fronts, and one disease front had all three clonal types. At this disease front no isolates with recombinant genotypes were found even though Al and A2 mating types were found in close proximity, i.e. the potential for sexual reproduction exists but we have found no evidence for it. Founder effects can explain the genetic diversity of P. cinnamomi in the disease fronts we examined.

Publication Type: Conference Item
Notes: Poster abstract: In M. van Keulen & M. Borowitzka (eds) Biodiversity, Biotechnology & Biobusiness. 2nd Asia-Pacific Conference on Biotechnology. Murdoch University, Perth, pp. 55
URI: http://researchrepository.murdoch.edu.au/id/eprint/10881
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